Friday, December 14, 2018

Rain coming to an end soon, but for how long? First thoughts on Christmas weather

Storms are currently rolling through the Mid-South, bringing a good splurge or rain. With the weekend now here, it brings the question: "How wet is the weekend supposed to be?" We will break down those rain chances, talk about how long we remain dry next week, and even take a peak at early projections for our Christmas forecast.

Tonight and Tomorrow

With that low pressure system gradually moving through the Mid-South, we are receiving showers and storms. As of 5pm, a bulk of the storm activity is getting close to wrapping up. That said, rain will not be ending. Instead, showers will continue for tonight as they remain scattered. When not light rain, drizzle/foggy conditions will be taking place. With the rain and clouds, don't look for much day-vs-night temperature changes taking place: low of 46.

National Weather Service's surface analysis map, showing the low pressure system bringing rain for the Mid-South.
Your Saturday will start with lingering rain as we wait for the low to propagate out of our area. The morning brings the greatest chance for rain, with shower activity becoming lighter and more isolated by the afternoon. Minimal diurnal shifts remain a part of the forecast, so our high will only be 50 degrees. Saturday night cooler air creeps in as we just start to lose the clouds. By this point, that low is now out of the area and high pressure starts to build in, bringing an end to our rain chances.

Sunday-Wednesday

Weather Prediction Center's QPF Totals showing that we aren't expecting much rain over the next 5 days.
Sunday through Wednesday, high pressure takes over, drying us out over this period of the forecast. With the dry weather comes the return of sunshine and clear nights: that means that we will see our diurnal temperature swings return. One thing of note is that today's low is going to be bringing in more Pacific like air, rather than Arctic, so we won't be pulling in colder air. Instead, look for our highs to range between the mid to upper 50s. Meanwhile, that diurnal swing effect means that we have our nighttime lows getting into the upper 30s.

Wednesday Night-Friday


Wednesday night brings the return of clouds and rain chances. A shortwave will drop from the north, meaning that we will have conditions, though minimal, for getting some shower activity going. With the rain comes cloud cover which should help insulate us and keeping our temps a little warmer overnight, with a low near the mid 40s.

A shortwave Wednesday night into Thursday in the Mid-South brings minimal rain chances that night and through the day.


Rain chances from Wednesday night last into Thursday, though rain chances never climb too high. The weak shortwave mean that at most we will see scattered rain chances through the day as we remain mostly cloudy. Highs remain in the mid 50s. By that evening, we dry out somewhat as the clouds try to hang on. Lows in the lower 40s.

Friday takes on an interesting look for the forecast with a low pressure system setting up behind the shortwave. Depending on how fast and how far the low digs will determine how much moisture is pumped out of this system late Friday and into Saturday. Likewise, we need to watch how fast the cold air on the back side of the low infiltrates. For now, we are sticking with our normal forecast and saying mostly sunny skies for your Friday and temps climbing to the mid 50s. We will keep watching Friday night into Saturday as more model runs/data come available.



Christmas Outlook





With Christmas less than two weeks away (queues holiday panic), we are close enough to get some rough idea what that time frame will look like. At the moment, as per the Weather Prediction Center, it looks to be a good chance we keep an above average weather pattern for that time frame. For those that don't like warm Christmases, we do have some good news so don't freak yet. Looks like we will be remaining near average precipitation wise, so no major wash outs for Christmas foretasted at the moment. In fact, ensemble forecasts look like they place us in a ridge during that time frame, which would mean we remain dry. All this said, there is still plenty of time for this forecast to change. Likewise, you know where to go to in order to find those changes!


The WPC's temperature and precipitation outlooks are showing near average precipitation and above average temperature probabilities for the week of Christmas.


Reggie Roakes
MWN Meteorologist

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MWN is a NOAA Weather Ready Nation Ambassador Meteorologist Erik Proseus is an NWA Digital Seal Holder

Saturday, December 8, 2018

Winter Weather Advisory in effect - what to expect

6:45pm UPDATE --

The forecast remains largely on track. Temperatures are dropping into the mid 30s this evening with several hours of precipitation to move through. Though they are not far from freezing at the surface, there remains a bit of warm air aloft as well that is keeping precipitation from changing to anything wintry just yet. Within the next few hours, some sleet could mix in, particularly in far northern areas of the metro (i.e., mainly Tipton Co). That area will also be the first to reach freezing tonight and a changeover to light freezing rain is expected, probably between 10pm-midnight.

Current StormView Radar loop
Temperatures are expected to hold for several hours overnight in the 32° (north) to 35° (south) range with the potential for a light wintry mix as far south as the the immediate metro as we head into the early morning hours (2-5 am). By sunrise, most precipitation will be gone, but lingering very light precip will likely be in the form of snow flurries or freezing drizzle through about 9-10am in TN portions of the metro.

Early evening HRRR model output shows a wintry mix remaining primarily north of the metro, but inching south into the immediate metro overnight with lingering flurries or freezing drizzle during the morning hours. (WeatherModels.com)

Overall, Tipton County stands the best chance for up to 0.10" of an ice glaze on exposed surfaces and bridges. Very light icing will also be possible in Crittenden, Shelby and Fayette Counties by morning. As stated below, "wait and see" is the best approach for morning travel. I expect the primary roads will be OK, but elevated roadways could be slippery. Treatment has not been applied ahead of time due to the constant rain before it changes over, so any road treatment will have to wait until the ice forms.


ORIGINAL POST (9:45am) --

Earlier this morning, the National Weather Service - purveyor of all watches/warnings/advisories - extended a Winter Weather Advisory south into the I-40 corridor, a.k.a. the Memphis metro along this part of I-40.  What does that mean for us? Let's answer your questions.

What is a Winter Weather Advisory?

The NWS issues a Winter Weather Advisory when a winter weather event is expected to cause a some degree of inconvenience, but is not expected to be a major hazard to travel and commerce (when a warning would be required). A combination of precipitation types is possible. An Advisory is basically a "Junior Warning." Caution is advised while traveling or working outdoors during an advisory.


When is it in effect and who does it include?

The advisory is in effect for those counties in purple above. Basically if your county has I-40 running through it or you are north of I-40, you're included. In addition, DeSoto and Tunica Counties are also included. The advisory runs from 6pm this evening through 9am Sunday.

What is driving this potential winter weather?

A fairly common wintertime pattern is in place, with a low pressure system moving along the Gulf Coast over the next 24 hours and an "inverted trough" (or weaker pressure extending north from the low) crossing the Mid-South. The low and trough are providing the lift and precipitation. Cold high pressure to our north is seeping the cold air into the region. Areas to the north of the metro, in northeast AR and northwest TN, are deeper into the cold air and are already experiencing winter weather conditions, including freezing rain, snow and some sleet.

As the Gulf low and trough move east tonight, the colder air will wrap in behind them, dropping south into the I-40 corridor. That will be the impetus for today's rain to change over to freezing or frozen precipitation. The kicker (there always is one, and it's the same as usual in these scenarios) is that precipitation will be departing late tonight as the cold air arrives.

The high-resolution NAM model from this morning shows temperatures remaining above freezing until early Sunday morning, when they could touch the freezing mark for a few hours. (WeatherModels.com)


So what can we expect in the metro, and when?

Rain today. Cold, yucky, hot chocolate-sipping, wintertime rain.

After 10pm tonight, some colder air will start working into the mid levels of the atmosphere and surface temperatures will be in the mid 30s. We could start to see some light sleet mix with the cold rain. No travel hazards are expected during this time. (Yes, you can safely go see the Grizzlies drag LeBron and the Fakers through the mud and return home with no issues.)


After midnight, and likely closer to 3am, surface temperatures will near freezing (especially in Tipton County) and precipitation will diminish in intensity. This is when we could see some light freezing rain (if the surface temperature drops to 32), sleet, or light snow mix in with the rain. We call it "wintry mix" because it's darn near impossible to know what exactly will fall. It should all be pretty light though, with minor accumulation on grassy surfaces, exposed objects, and maybe some bridges possible, especially in Tipton County.

The high-resolution HRRR model from this morning shows wintry precipitation remaining north of the metro until early Sunday morning, as precipitation is departing. The best chance of minor accumulation will be Tipton County and points north. (WeatherModels.com)

The high-resolution NAM model depiction of total accumulation of various winter weather types above. Sleet (top left, orange) should mainly avoid the metro with no accumulation expected. Snow (lower right, blue) should be about the same. Minor accumulation of freezing rain (top right, red) could occur as far south as I-40, while rain (lower left, green) will be widespread. (WeatherBell)

By dawn, most precipitation will be over. After that, a bit of freezing drizzle or flurries are possible for a couple more hours but shouldn't affect morning church-goers or dedicated joggers. Overall, we advise a "wait and see" approach to those headed out in the early morning, but honestly, I don't really expect too many problems. A slippery bridge here or there, mainly north of I-40, is possible. With lows right at 31-32° and highs in the upper 30s, by late morning everything should be thawing and drying out.

Starting Monday, a warming trend brings us back to near 50 by Tuesday with highs remaining in the 50s the rest of the week. Rain is a good bet Thursday and Friday with no winter shenanigans in view. Here's hoping for (and we're forecasting as of now) a dry and seasonal weekend next week!

Stay updated

Get the latest updates on our winter weather threats via our Facebook and Twitter feeds, as well as the latest precipitation-typed radar loop, current conditions around the metro, and forecast in our mobile app. All links are below.

Erik Proseus
MWN Meteorologist

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Follow MWN on Facebook and Twitter for routine updates and the latest info!
Complete MWN Forecast: MemphisWeather.net on the mobile web or via the MWN mobile app
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MWN is a NOAA Weather Ready Nation Ambassador Meteorologist Erik Proseus is an NWA Digital Seal Holder

Thursday, December 6, 2018

Cold rain returns, but let's talk about frozen precip potential

Below-average temperatures will continue to hold onto the Mid-South over the next several days with highs remaining in the lower to mid 40s and overnight lows in the mid 30s. The next few days will be characterized by scattered showers throughout the day, continuing into this weekend. There are some concerns about frozen precipitation Saturday night into Sunday morning, but more on this later.


Overall, expect areas near and south of the metro area to receive more precipitation over the next few days with decreasing precipitation as you move northward. Some areas could see up to 2 to 3 inches of precipitation over the next few days (yes this is the rain-only form).

The 72-hour precipitation map from the Weather Prediction Center has areas around the Mid-South receiving 2 to 3 inches of precipitation between now and Sunday morning with others receiving closer to an inch. (Pivotal Weather)

Today

We will continue our downward trend in temperatures today with highs only expected to reach 46. Cloudy skies will remain overhead as we prepare for scattered showers that will arrive by evening. Breezy winds around 10 mph could make things feel even colder at times today. Be sure to bundle up before heading out the door and you may want to grab the umbrella for this afternoon and evening.

The HRRR model loop shows scattered showers increasing in coverage this afternoon into this evening. These scattered showers will continue into tomorrow. (WeatherBell)

Friday & Saturday

We will end this week with some pretty chilly and dreary conditions. Showers will begin to increase throughout the day Friday, continuing into the overnight hours Friday and into Saturday. Rain on both days will be a very cold rain, so keeping an umbrella handy will be ideal. 

The high-res NAM model from early Friday through Saturday evening shows scattered, mainly light, showers on Friday with continuous rain through most of the day Saturday. (Tropical Tidbits)

Temperatures will stay just warm enough throughout both days that wintry precipitation is not a concern. Highs both days will be in the low 40s with overnight lows in the mid 30s, so temperatures will not vary too much through the day. 

Sunday

Showers will continue through the early morning hours on Sunday and could *potentially* turn into light snow or freezing rain. The biggest concern with Sunday's forecast is where our temperatures will be. If surface temperatures can cool enough, then we could see some freezing rain. Temperatures just aloft will also be borderline for the potential for some light snow. It appears right now that there is a slightly better chance for light snow mixing with rain than freezing rain.  It will remain cold on Sunday, with most of the day spent in the 30s.

GFS model loop from late Saturday through mid-day Sunday shows a very small window of opportunity for frozen precipitation early on Sunday. Regardless, any precipitation should begin to move out by the afternoon hours on Sunday. (Tropical Tidbits)
Those to the north of the metro area have the greatest chance of seeing freezing precipitation from Saturday into Sunday, as surface temperatures will be colder the farther north you move. If you have travel plans north of Memphis this weekend, keep that in mind.

Greatest chance of seeing any type of wintry mix and snow appears to be north of I-40. Chances increase the farther north of the metro area you move. (NOAA/NWS)

This is an evolving forecast that will need to be monitored over the next few days. For latest trends and thinking, be sure to check out our social media accounts (linked below) and the MWN forecast online and on our app.


Next Week

Things will remain around to slightly below average early next week. For those curious, around this time of year our "average" high temperatures is in the low 50s with our "average" low temperature in the mid 30s.

Later next week, we will begin to warm slightly with highs nearing the upper 40s to lower 50s. Overnight lows will be in the low to mid 30s. This will leave us right around that average category. Through the first half of next week, we should remain dry with plenty of sunshine for all. 

Weather Prediction Center 6 to 10 day outlook for temperature shows the Memphis area right around average for next week. (Pivotal Weather)

Caroline MacDonald
MWN Meteorologist

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Follow MWN on Facebook and Twitter for routine updates and the latest info!
Complete MWN Forecast: MemphisWeather.net on the mobile web or via the MWN mobile app
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MWN is a NOAA Weather Ready Nation Ambassador Meteorologist Erik Proseus is an NWA Digital Seal Holder

Monday, December 3, 2018

Much cooler week ahead; keeping an eye on this weekend

After an extremely warm end to last week and the weekend, we have finally dropped back down into a fall to winter-like pattern. Temperatures are expected to remain below average through the entire week with rain chances coming towards the weekend. Dry conditions will remain for the first half of the week with some sunshine expected by midweek.

First half of the week 

We will continue to transition back into our colder spell over the next few days with high temperatures slowly falling through the 40s. While today's high will be in the upper 40s, Tuesday and Wednesday's highs will be in the lower to mid 40s.

Clouds will begin to increase today and hang around a bit longer tomorrow. However, by Wednesday skies will begin to clear to introduce more sunshine to our weather pattern. Luckily, we are not expecting any rain over the next few days.

The Weather Prediction Center's Frontal Analysis for early Wednesday shows high pressure dominating much of the central and southeastern regions of the U.S. This high pressure will help to keep rain chances out through the first half of the week. (NOAA/WPC)
Overnight temperatures will fall to near freezing tonight, with temps dipping down into the upper 20s to lower 30s Tuesday and Wednesday nights. If you haven't already, you may want to pull out the extra blankets and turn on the heat once again.


Thursday & Friday

Our dry spell could only last so long as rain chances are re-introduced Thursday evening. We should make it through the majority of the day with partly sunny skies and highs in the upper 40s. Scattered shower chances will begin to increase into the evening to overnight hours with additional showers possible on Friday.

GFS model loop from Thursday evening through late Friday evening show very light showers moving through the Mid-South. Isolated showers will be possible Thursday evening with an increase in showers on Friday. (TropicalTidbits)
Light rain is expected to continue into Friday, helping to keep high temperatures in the lower 40s. Showers shouldn't be too heavy, but heavy enough that you may want to keep the umbrella handy Friday to keep the cold, drizzle away. 


Glance at this upcoming weekend

Rain and cooler temperatures are expected to continue into this weekend. Highs are expected to be in the upper 30s to near 40 both Saturday and Sunday with overnight temperatures falling near to below freezing.

Saturday looks pretty gross if you ask me with a cold rain expected through a good portion of the day. While we are several days out, we will need to continue to keep an eye on things for Saturday night.

GFS loop from early Saturday through Sunday evening shows showers moving through the Mid-South on Saturday with a possible wintry mix mixing in overnight Saturday. Rain and this possible wintry mix should move out Sunday morning. (TropicalTidbits)
Temperatures may become just cold enough to allow for some flakes to mix in on Saturday night. This is still only a possibility, but worth mentioning. Moisture from Saturday's showers may move out earlier than expected, which would eliminate this wintry mix potential. However, the chance still remains for now. We will keep an eye on this through the remainder of the week, and will provide additional information as we draw closer to the weekend. You can check our latest thinking in the MWN Forecast anytime via the web or our mobile app (links provided below).


Caroline MacDonald
MWN Meteorologist

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Follow MWN on Facebook and Twitter for routine updates and the latest info!
Complete MWN Forecast: MemphisWeather.net on the mobile web or via the MWN mobile app
Download our iPhone or Android apps, featuring StormWatch+ severe weather alerts!
MWN is a NOAA Weather Ready Nation Ambassador Meteorologist Erik Proseus is an NWA Digital Seal Holder

Wednesday, November 28, 2018

Warming trend to finish the week, t'storms expected Friday night

We have had quite the temperature roller coaster over the past few days with this trend expected to continue. Just one week ago, highs were nearing the 60s while Monday and Tuesday only had highs in the lower 40s. For right now, we are going back up on our temperature roller coaster as highs will reach near 70 this weekend.


We know a lot of people have questions about the forecast over the next few days, especially for this weekend, so we will get right to it.

Rest of Today

Cloud coverage is expected to continue increasing into the afternoon hours. Latest satellite images show clouds increasing to our north and west and drifting towards our area. Clouds will hang around into the overnight hours, and combined with a south wind, will help to keep temps a little warmer than we've seen recently overnight. Lows will reach near 46. 

Latest (around 1 PM 11/28/2018) GOES 16 visible satellite loop. (College of DuPage)

Tomorrow

Into tomorrow, we will begin to shift into a somewhat-muggier period. We aren't talking summertime mugginess, but it will be a little more humid than we have seen recently. Mostly cloudy skies and warmer conditions can be expected as highs near 63. Scattered rain chances are possible throughout the day, with rain chances increasing slightly. 

Friday

Cloudiness will continue into Friday with scattered showers being possible throughout the day. Highs will near 70, with breezy winds out of the south making things feel even muggier.

Heavier showers and a few potentially strong to severe thunderstorms will be possible during the overnight hours on Friday. A few thunderstorms could develop Friday evening, but timing suggests that the strongest storms, if we get any, would occur overnight.
The Storm Prediction Center currently includes Memphis in a "slight" risk (level 2/5) with surrounding areas either in the "marginal" (1/5) or "slight" risk categories as well. (NOAA/SPC)
All hazards are possible and cannot be ruled out at this time, but the main concerns appear to be periods of heavy rainfall and damaging wind gusts. We will continue to keep an eye on things over the next few days, so be sure to keep up with us on our social media pages (linked below) for the most up-to-date information.

Saturday

Oh Saturday. Saturday is a busy day for many in Memphis with the St. Jude Marathon series taking place (I will be running in the half marathon too!). There is some good news and bad news for runners participating in this year's races depending what running conditions you typically like to run in. Lingering showers are possible during the early morning hours of race day, but are expected to clear out around or before 9 AM-ish. Clouds will likely hang around for the majority of the morning during all of the races, although some clouds may begin to clear out as the morning progresses. As for our temps, temps will remain in the low 60s around race time but be pretty muggy as well. Additionally, winds will be pretty breezy (10-20 mph), which could help out with the muggy temps but may cause you to be running into the wind at times.


Regardless, severe weather is not expected to linger that far into the morning hours. Be prepared for warm and muggy conditions throughout the race with light rain possible before 9 AM.
NAM model loop shows heavy showers during the Friday overnight hours, with showers clearing out during the morning hours. (TropicalTidbits)
For the rest of the day, skies will continue clearing after the morning's cloudiness. Highs will reach the lower 70s by the afternoon.

Sunday into Next Week

Somewhat "cooler" weather is expected to return to the Mid-South on Sunday and continue into the beginning of next week. Luckily, we are not expecting another frigid cold snap, just highs lowers 60s on Sunday and 50s for the first half of next week. Overnight temps will dip into the 40s.

While widespread showers aren't expected, we could see a few isolated showers Monday and Tuesday. Forecasting showers this far out should be taken with a grain of salt, so I will leave it at that. Enjoy the somewhat fall-ish weather coming next week!


Caroline MacDonald
MWN Meteorologist

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Follow MWN on Facebook and Twitter for routine updates and the latest info!
Complete MWN Forecast: MemphisWeather.net on the mobile web or via the MWN mobile app
Download our iPhone or Android apps, featuring StormWatch+ severe weather alerts!
MWN is a NOAA Weather Ready Nation Ambassador Meteorologist Erik Proseus is an NWA Digital Seal Holder

Sunday, November 25, 2018

Say good-bye to 60s; colder weather is on the way

Hopefully everyone got to enjoy the period of warmer weather, especially since it happened to fall during the holiday period. That said, tonight's cold front is going to quickly bring an end to that. Brace yourselves, grab the jacket, and check out the upcoming forecast for this week!

The European model (ECMWF) shows that by 6am Monday we will see temperatures around 34 degrees. (WxBell)

Tonight

Very windy conditions are accompanying tonight's cold front thanks to such a strong temperature gradient. Source: National Weather Service

The small band of rain from today's cold front is going to be scooting out of here very fast. In fact, rain wraps up early this evening. The big topic is what's behind it: very windy conditions. With such a strong pressure gradient associated with the front, plan on hanging on to more than just your hat. Gusts will be over 30 mph through a portion of the night. Skies will be quickly clearing overnight as well. Accompanying these wind conditions will be a very fast cool down. How fast of a cool down? Well, at 5pm the temperature was 64 degrees. Tonight's low is set for 33 degrees. That's a 31 degree temperature change in about 12 hours. 

Monday

Sunshine returns for your Monday, but make sure you have the coat as you are running out the door to work. After tonight's low of 33 degrees, it will be a struggle to warm during the day and temps will only climb to 44 degrees. Don't forget about that wind, too. Winds will still be blowing, but not as badly as tonight. Look for a northwest wind around 13 mph to make for a blustery feeling. Monday night will be very chilly: the coldest night of the week with a low of 27, thanks to effective cooling due to minimal wind and no cloud cover.

Tuesday through Thursday

The weather takes a "chill pill" through the mid week. Temperatures will slowly be on the rise (key word slowly). On Tuesday, look for another day with highs in the 40s (but upper 40s at least). Wednesday we climb into the lower 50s and finally by Thursday we climb back into the lower 60s. That slow warm up will be a result of the Canadian high pressure shifting to our east, allowing a south wind  to return to the region. Unfortunately, along with it will come some moisture to feed some rain, but Thursday will only be a minimal chance of a few showers. The best rain chances hold off until Thursday night/Friday and into the weekend. All the while, lows through this time period will also slowly be on the rise, starting in the upper 20s for Tuesday night and finishing off in the lower 40s by Thursday night.

The American climate model (CFS) shows well below average surface temperatures for the upcoming 5 days. (WxBell)


Friday

Thanks to the input of moisture with the return of our southerly wind and the combination of weak shortwaves that act as triggers, we will see the chance for stray showers. With the return of rain also comes with warmer weather. Look for a high of 65 degrees. Friday night will feature cloudy skies, mild weather (low of 55), and a chance of showers.


Saturday and Sunday


Models place a strong low in Missouri Saturday morning to mid-day, bringing rain and potential storms to Memphis. (Tropical Tidbits)
Models are coming into agreement for timing of a strong low pressure system to bring a cold front with accompanying rain and possible storms Saturday, with the best lock in for timing being earlier in the day, at the moment. That means for those prepping to run the St.Jude Memphis Marathon, you may want to start looking into a great pair of swimming googles. With such a strong system and a low located around the Missouri region, we will be keeping an eye on this event, but will refrain from mentioning severe weather at the moment (wait, did I just mention it??). Look for a high in the mid 60s Saturday (which could change if we get any change on arrival time of the front). Saturday night, skies will remain mostly to partly cloudy as temps start to drop, with a low foretasted in the mid 40s.

Sunday should be much less of a headache weather-wise unless the front slow significantly. Partly cloudy skies and a high in the upper 50s for now.

Reggie Roakes
MWN Meteorologist

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Follow MWN on Facebook and Twitter for routine updates and the latest info!
Complete MWN Forecast: MemphisWeather.net on the mobile web or via the MWN mobile app
Download our iPhone or Android apps, featuring StormWatch+ severe weather alerts!
MWN is a NOAA Weather Ready Nation Ambassador Meteorologist Erik Proseus is an NWA Digital Seal Holder