Archive for May, 2010

Update on WKU meteorology class investigating storms in the plains and recap of May 21st severe event

May 29, 2010

We start one week ago yesterday (May 21st),  their second day out covering storms,  we had our own event here in Kentucky. Enough instability more than what was predicted  allowed  thunderstorms to develop along a week warm front and a cold front further west. These storms  developed into supercells near the warm front positioned over the bluegrass by Friday evening. These supercells were scattered but produced hail to the size of golfballs, numerous reports of wall clouds and also had multiple signs of rotation on radar prompting several tornado warnings. Along the cold front a squall line of thunderstorms developed from Bowling Green to Louisville with gusty winds from 35-65 mph in most cases, there was one tornado touchdown near Elizabethtown. Kentucky had them beat for now in terms of severe weather, this would not last long similar to any lead any 16 seed gets in a ncaa tourney game.

Later that day they our storm team in the plains caught up with a supercell near the WY/NE border and tracked this storm for several hours that did produce a tornado which was missed but they saw some funnel clouds and wall clouds. The next day several tornadoes were observed as they tracked a storm from the inital formation. In order to do this the forecast thinking for the day had to be dead on with where storms would develop and this was the case. Here is there forecast map for May 22nd.

Cape which is an indicator of atmospheric instability was over 5000 J/KG so the storms that fired had the potential to be explosive. After the formation of the storm they set-up just southeast of the hook where tornadoes most often occur with supercells.

radar of the storm

Tornado pics

sky is getting a little dark on the last one, wow!

On May 23rd the group went south where more severe storms were expected. The first cell they tracked two cells, the first they were able to capture the classic structure of this storm. The second storm they set-up about 15 miles away and saw another tornado.

cell 1

cell 2

On May 24th the SPC had a moderate risk for a large portion of the plains. However storms were moving very quick, to quick to track. They went back and forth between storms but were not able to really lock on to any particular storm like the previous few days but they did get to see how a squall line is structured.

May 25th was a much better day in Nebraska this time tracking a cell from 4:30 to 10:30 pm local time getting once again non the southeast side of the storm to avoid the hail core. With this storm they saw a tornado touchdown first hand and saw a total of 5 tornadoes from this storm!!!

initial funnel

touchdown

At first they were over 5 miles away but got within 2 miles of another tornado!!

On May 26th the storm team saw the same thing I did and posted that day the observation from the Denver international airport of a funnel cloud so of course that is the area they are near that day. This cell produced more funnels but no touchdowns likely due to the higher elevations and drier airmass.

The last few days have been a bust so far but I don’t think there complaining after the fast start they had. Looking back those stuck in KY as the 16 seed are now 100 points behind in that game after an interesting May 21st and I for one hope to be able to switch spots next year.

Looking at this weekend there is a slight risk of severe storms Saturday over the northern plains and Monday, memorial day in Kansas with a day 4 risk in the northern plains. For us in Kentucky we have to watch this very same front by the middle of next week to see if a mcs complex can dive southeast into the lower Ohio valley and produce severe weather around here. For this weekend weatherwise we’ll have isolated storms sat-sun then increase the coverage to scattered on memorial day as a weak cold front gets closer.

Our eyes also should be turned to tropics a bit as well with the Canadian model bringing a tropical storm into Tampa bay and taking its leftovers into eastern Kentucky for June 2nd-4th.

the gfs has this feature to some extent as well, we’ll see not biting untill the euro starts to show it as well.

– all the photos are from the wku storm group and are not mine.

link to track the group across the plains.

http://people.wku.edu/michael.grogan/FieldMethods/

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some storms today with locally hvy rains

May 28, 2010

This morning we have a thin band of thunderstorms from bourbon county and the city the paris to Lexington to just east of Harrodsburg in mercer county, some of the locations impacted in Jessamine county saw locally hvy rains yesterday. with the thunderstorms moving from ne to sw over the same areas  local rises in streams and creeks are possible. Gusty winds and small hail with any strong storms are possible from development this afternoon over the region. An example of local nature of this activity can be seen in Woodford county yesterday where around the castle and north toward midway hvy rains fell much of the evening however in Versailles only trace amounts of rain fell.

this from the nws…

…STRONG THUNDERSTORMS WITH TORRENTIAL RAIN AND DANGEROUS
LIGHTNING…

AT 937 AM EDT…NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING
STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM 6 MILES NORTH OF
NICHOLASVILLE TO HARRODSBURG. THESE STORMS WERE DRIFTING SOUTHWEST.

FREQUENT CLOUD TO GROUND LIGHTNING…AND TORRENTIAL RAIN WITH
RAINFALL RATES OF AROUND TWO INCHES PER HOUR REDUCING VISIBILITIES TO
LESS THAN ONE HALF MILE…ARE EXPECTED WITH THESE STORMS.

THESE STORMS WILL ALSO IMPACT…
   NICHOLASVILLE…

THESE STORMS WILL AFFECT INTERSTATE 75 IN KENTUCKY BETWEEN MILE
MARKERS 111 AND 113

radar

Central Great Lakes sector loop

Isolated strong to severe storms today

May 27, 2010

1. Today scattered storms have fired to our north with a warm and marginally unstable airmass in place. Some of these storms are strong to severe with small hail and gusty winds.

radar

Central Great Lakes sector loop

I expect these thunderstorms to move into Kentucky west of I-75 this afternoon. Notice the odd storm motion moving from northeast to southwest as well. Right now I do not expect a watch to be issued but isolated severe storms are possible.

For the rest of the weekend forecast please read below. Updates will be issued in the comments section as needed on today’s storms.

Weekend Forecast

May 26, 2010

I will be in Louisville most of Thursday and Friday so I’m posting this a little early with the additional benefit of getting the memorial day forecast sooner.

first the 4 pm et Wednesday observation from the Denver international airport

“Funnel Cloud Thunderstorm and Windy” don’t see that everyday an actual site reporting a funnel cloud in the hourly observation!!!

1. Over the past several days we have had warm and humid weather with isolated thunderstorms thanks to some moisture although limited coming from a subtropical low off the east coast and from the gulf. Look for the coverage of storms to increase a bit from isolated 10-20% to scattered 30-50% with a very weak front moving into the lower Ohio valley which will serve as a trigger. This front won’t have much change in wind direction or temperature so expect the same spread of 60’s for lows and 80’s for highs Thursday and Friday with the best chance for storms in the afternoon and evening.  Also with an LI of -2 and  CAPE just over 1000 a few of these storms may be strong with some instability  of the atmosphere.

2.  Some leftovers from the front may still be enough to trigger an isolated storm on Saturday or Sunday in the heating of the day with 80’s for highs and 60’s for lows once again.

3. The next front this one a little stronger moves into the region for Memorial day and Tuesday allowing for a chance for scattered storms ( I’ll go 30-50% but may need to go higher for Tuesday). By the middle to end of next week the front may be in position to our north and west to allow for the formation and passage of organized mcs’s which would increase the severe threat with this frontal boundary. Once again 60’s for lows and 80’s for highs will be the rule.

4. Over the weekend I’ll give another update on the WKU class out in the plains so far they have seen 10 tornadoes in less than one week of storm tracking!!!!

5. I’ll post my summer forecast on June 1st( Tuesday)

summertime pattern this week

May 23, 2010

1. here is the overall set-up this week.

a blocking high over the east coast should keep frontal zones out in the high plains this week. Also we still have a sub-tropical low off the east coast which should stall offshore. With return flow from the gulf some tropical moisture should come north into the region to promote isolated thunderstorms each day but with mostly sunny skies each day any thunderstorm could produce flash flooding. With a muggier airmass lows should stay in the 60’s with highs in the mid 80’s on average.

2. my goal is to have my summer forecast for the nation up by June 1. The last two winter forecasts I have hit dead on, now onto nailing the summer forecast.  

3. 1-2 of new rain is needed to make this the wettest May on record for us.

edited to add this: the subtropical low off the carolina coast  has a low chance to delevop into a tropical depression.

1. THE NON-TROPICAL LOW PRESSURE SYSTEM CENTERED BETWEEN BERMUDA AND
THE BAHAMAS REMAINS DISORGANIZED…AND THE POTENTIAL TO ACQUIRE
SUBTROPICAL CHARACTERISTICS DURING THE NEXT DAY OR SO IS
DIMINISHING. THERE IS A LOW CHANCE…20 PERCENT…OF THIS SYSTEM
BECOMING A SUBTROPICAL CYCLONE DURING THE NEXT 48 HOURS. THIS LOW
IS MOVING SLOWLY TOWARD THE NORTH-NORTHWEST AND IS STILL PRODUCING
A LARGE AREA OF SHOWERS AND THUNDERSTORMS ALONG WITH GALE FORCE
WINDS. FOR ADDITIONAL INFORMATION…PLEASE SEE HIGH SEAS FORECASTS
ISSUED BY THE NATIONAL WEATHER SERVICE…UNDER AWIPS HEADER
NFDHSFAT1 AND WMO HEADER FZNT01 KWBC. NO FURTHER SPECIAL TROPICAL
WEATHER OUTLOOKS ON THIS SYSTEM ARE ANTICIPATED.