Monday, April 18, 2011

Forecast for Starkville, MS and Leesburg, VA

Starkville, MS

Overnight-  Clear with a low temperature around 47.

Monday-  Mostly sunny and warmer with a high temperature around 83.

Monday night-  Mostly clear with a low temperature around 62.

Tuesday-  Mostly sunny with a high temperature around 85.

Tuesday night-  Scattered clouds overnight.  Low temperature around 66.

Wednesday-  Scattered clouds with showers and thunderstorms developing late in the afternoon.  High temperature around 84.

Wednesday night-  Showers and thunderstorms during the evening, with a few showers possible overnight.  Low temperature around 61.

Thursday-  Sun and clouds mixed throughout the day with scattered showers and thunderstorms.  High temperature around 79.

Extended Forecast-  A stray thunderstorm is possible Friday afternoon with highs around 80.  Showers and thunderstorms are likely Saturday afternoon with highs in the lower 80s.  Clear skies will return Sunday with highs in the upper 70s.

Leesburg, VA

Overnight-  Mostly clear with a low temperature around 51.

Monday-  Scattered clouds throughout the day.  High temperature around 70.

Monday night-  Mostly cloudy with a low temperature around 53.

Tuesday-  Mostly cloudy with showers and thunderstorms developing during the afternoon.  High temperature around 72.

Tuesday night-  Showers and thunderstorms during the evening, then remaining mostly cloudy overnight.  Low temperature around 55.

Wednesday-  Scattered clouds and sun with showers and thunderstorms developing during the afternoon.  Some storms may be strong with damaging winds and hail.  High temperature around 81.

Wednesday night-  Showers during the evening with partial clearing overnight.  Low temperature around 50.

Thursday-  Mostly sunny with a high temperature around 66.

Extended Forecast-  Showers and thunderstorms will return late Friday night and linger through Sunday.  High temperatures will be in the mid 60s Friday, in the upper 60s Saturday, and around 70 Sunday.

Sunday, April 17, 2011

Forecast for Starkville, MS and Leesburg, VA

Starkville, MS

Overnight-  Clear and cool.  Low temperature around 42.

Sunday-  Sunny and warmer with a high temperature around 76.

Sunday night-  Clear with a low temperature around 45.

Monday-  Mostly sunny with a high temperature around 82.

Monday night-  Mostly clear and mild with a low temperature around 61.

Tuesday-  Mostly sunny and breezy.  Winds gusting up to 30 MPH.  High temperature around 84.

Tuesday night-  Scattered clouds overnight.  Low temperature around 63.

Wednesday-  Sun and clouds with scattered showers and thunderstorms developing late in the afternoon.  High temperature around 83.

Extended Forecast-  Showers and thunderstorms will be possible Thursday afternoon with highs in the lower 80s.  Clear skies will return Friday and Saturday with highs around 80.

Leesburg, VA

Overnight-  Mostly clear with a low temperature around 49.

Sunday-  Sunny and windy.  Winds gusting up to 40 MPH.  High temperature around 67.

Sunday night-  Scattered clouds overnight.  Low temperature around 45.

Monday-  Mostly cloudy for most of the day.  High temperature around 69.

Monday night-  Mostly cloudy with scattered showers overnight.  Low temperature around 53.

Tuesday-  Mostly cloudy with showers and thunderstorms during the afternoon.  High temperature around 72.

Tuesday night-  Showers and thunderstorms during the evening, with partial clearing overnight.  Low temperature around 57.

Wednesday-  Scattered clouds and sun with showers and thunderstorms likely during the afternoon.  High temperature around 81.

Extended Forecast-  Expect scattered clouds Thursday and clear skies Friday.  Highs will be in the mid 60s Thursday and lower 60s Friday.  Showers and thunderstorms will return Saturday with highs in the upper 60s.

Saturday, April 16, 2011

Possible Tornado in Leesburg

As the storms moved through Leesburg, the southern edge rushed eastward, met by southeasterly winds at the surface.  As this happened, the storm began to rotate and a brief tornado likely developed directly over Leesburg, touching down for probably less than a minute.  As of right now, the only damage report from Leesburg is a large sign blown down and multiple trees down along S. King street and Davis Ave.  Here are some radar images during the storm:

 This first radar image shows the hook echo directly over the eastern side of Leesburg.  Notice the defined "hook" shape as the storm pulls wind and rain from the storm and rotates.

 This is a closer view from the terminal radar used by Dulles airport.  You can see the clear hook shape over Leesburg which is likely where the tornado was.

This is storm relative velocity at the same time as the previous images.  The bright green on the south side of Leesburg represents winds traveling southbound at 50 to 60 MPH, while the pocket of dark red just to the east of Leesburg represents winds traveling north at 30 to 40 MPH.  This is known as wind shear, or a "couplet" on radar, where wind travels in opposite directions over a very small area.  This commonly represents rotating winds associated with a tornado.

Severe Weather- Leesburg, VA

Severe thunderstorm warning now in effect for Loudoun county including Leesburg until 7:45 PM.  Expect strong winds in excess of 50 to 60 MPH, hail to the size of quarters, and heavy rain.  This storm will move through Leesburg by 7:20 PM.



This is storm relative velocity.  Green is wind moving toward the radar which is just east of Leesburg.  The bright green just west of Leesburg is wind gusting up to 50 to 60 MPH.  Some rotation associated with this, so be alert.

Severe Weather- Leesburg, VA

Another round of storms will move through Leesburg within the next hour to hour and a half.  The first line along the Blue Ridge mountains in western Loudoun county will likely merge with the faster eastbound line entering Clarke county and push east.  Expect heavy rain, gusty winds in excess of 50 to 60 MPH, and hail to the size of quarters with these storms.  The yellow box indicates a severe thunderstorm warning which is in effect for Loudoun county until 7:15 PM but does not include Leesburg yet.  Another warning will likely be issued within the next 30 to 45 minutes to include Leesburg as these storms intensify.  I will try to keep this updated as storms develop.  A tornado watch remains in effect for the entire area until 9PM tonight, however after this line passes the severe weather threat will diminish.

Severe Weather- Leesburg, VA

While it may seem strange that severe weather could be possible on a cloudy day with temperatures in the upper 50s, it is happening.  This is the current radar image for areas in and around Leesburg.  The large red box indicates a tornado watch which is in effect until 9 PM tonight.  There is a severe thunderstorm warning (yellow box) on the storm in Shenandoah and Frederick county, which is moving to the east-northeast.  This storm is capable of producing winds up to 60 MPH and heavy rain.  Expect this storm within the next 1 to 2 hours.  I do not expect very many tornadoes to develop today around Leesburg given the lower temperatures and available moisture.  However, that does not completely eliminate the risk.  Winds from the southeast at the surface coupled with winds from the southwest just 10,000 feet from the ground will help thunderstorms to rotate.  I will do my best to keep this updated as severe weather develops.

Forecast for Starkville, MS and Leesburg, VA

Starkville, MS

Overnight-  Mostly clear and breezy.  Winds gusting up to 30 MPH, calming down around sunrise.  Low temperature around 51.

Saturday-  Mostly sunny and cooler with a high temperature around 66.

Saturday night-  Clear and cool with a low temperature around 43.

Sunday-  Sunny and warmer with a high temperature around 78.

Sunday night-  Scattered clouds overnight.  Low temperature around 50.

Monday-  Mostly sunny with a few afternoon clouds.  High temperature around 81.

Monday night-  Scattered clouds overnight.  Low temperature around 62.

Tuesday-  Mostly sunny with scattered thunderstorms developing during the afternoon.  High temperature around 83.

Extended Forecast-  An afternoon thunderstorm is possible Wednesday and Thursday with highs in the mid 80s Wednesday and lower 80s Thursday.  Thunderstorms will be likely Friday with highs in the lower 80s.

Leesburg, VA

Overnight-  Mostly cloudy with showers possible by sunrise.  Low temperature around 47.

Saturday-  Mostly cloudy and breezy with showers and thunderstorms throughout the afternoon.  Some storms could be strong during the afternoon with damaging winds in excess of 60 MPH and heavy rain.  Winds gusting up to 40 MPH outside of thunderstorms.  High temperature around 65.

Saturday night-  Cloudy with showers likely during the evening.  Partial clearing overnight but remaining breezy.  Winds gusting up to 30 MPH.  Low temperature around 46.

Sunday-  Mostly sunny and breezy.  Winds gusting up to 30 MPH.  High temperature around 66.

Sunday night-  Mostly clear with a low temperature around 45.

Monday-  Scattered clouds with a shower possible during the afternoon.  High temperature around 67.

Monday night-  Scattered clouds overnight.  Low temperature around 52.

Tuesday-  Mostly sunny and warmer with a high temperature around 75.

Extended Forecast-  Showers and thunderstorms will be possible Wednesday, some possibly strong, with a high temperature in the lower 80s.  Clear skies will return Thursday with highs in the lower 70s.  Showers and thunderstorms will be possible again Friday with highs around 70.