Saturday, March 26, 2011

March 26 Strong Supercell Concern

There is a real concern in the Texas area due to a singular supercell that may turn violent at any moment.
Some indicators of this are the following:
-Craven/Brooks Significant Severe weather indicator are 3 and a half times the amount needed to begin reasonable probabilities for significant severe weather.
-Effective Bulk Wind Shear (what is needed for tornadoes due to winds in different directions) are 2 times the amount minimally needed for probability of supercells.
-CAPE values are 1000 j/kg above what makes the atmosphere considered unstable. Also an indicator of energy in the atmosphere.
-Lifted Index is at -9, while values under -6 are classified as extremely unstable. Severe storms are likely with a lifting mechanism.
-CAPE Downdraft values are off the charts, meaning downdrafts from clouds are likely.

Overall, this is a very intense situation.
Below is real-time radar image of these supercells.

March 26- Tomorrow's Forecast


Tomorrow, we will see a string of low pressures across the South make for a wet day across that region. With a cold front moving through, if a dry line develops, I would not be surprised to see some form of severe storms. Even at the time of publishing, a very strong supercell is catching my eye in Texas due to this front, which is currently a trough.
On the north end of the string of low pressures will be some snow. Accumulations are not expected to be significant. Just to the west will be some icy conditions, but those are not expected to be significant, either. We will definitely watch that area tomorrow.
Out west, more low pressure systems will create more snow in the Rockies. On the West Coast, rain will be found as a low pressure off the shore, just to the north and out east will surround the Northwest.
In the Plains will be some icy conditions and snow showers mixed in as temperatures hover around freezing.
Out in the Northeast will be some snow showers.

Trough/Dry Line Poses Concerns

A trough associated with a low pressure system is creating a possible dry line in Texas. Below is a visible satellite imagery at time of publishing.
In Texas, we definitely see a line separating what appears to be dry air and moist air. Should that be a dry line, a severe weather situation would definitely be possible.
Wind shear indicates that any storms that develop would have potential to have rotation.
CAPE values are at 3000 around a section of this trof/dry line, so any storms developing could pose a serious tornadic risk.

POTENTIALLY DANGEROUS SITUATION March 26

This is a PDS.

AS OF 1:08PM CDT, THE STORM PREDICTION CENTER HAD OUTLINED A PORTION OF THE SOUTHEAST IN A MODERATE RISK OF SEVERE STORMS.
BELOW IS RADAR IMAGERY AS WELL AS CURRENT RISKS.
SUPERCELLS ARE BEGINNING TO DEVELOP. SUPERCELLS ARE THE MAIN CAUSE OF TORNADOES. A TORNADO WATCH HAS BEEN ISSUED FOR A LARGE PORTION OF THE SOUTHEAST AS SEEN BELOW. IT EXPIRES AT 8PM CDT.
ANYONE IN THIS WATCH BOX SHOULD PREPARE FOR:
-TORNADOES
-ISOLATED STRONG TORNADOES
-VERY LARGE HAIL
-DAMAGING WINDS

March 26 Today's Forecast

SOUTHEAST
Showers and thunderstorms currently ongoing are expected to possibly redevelop and intensify over an area of the Southeast where severe weather is possible today.

SOUTH CENTRAL
Some of the precipitation from those Southeast storms will develop from a low pressure system associated with the other system forming the severe weather.

SOUTHWEST
The Southwest should be fine except for a West Coast storm that may cause some sprinkles and showers the closer you get to the Coast.

NORTHWEST
The Northwest will be soggy and gross with another low pressure system off the West Coast.

NORTH PLAINS
Snowfall will occur, associated with a low pressure system. It could be heavy at times, with accumulations up to 6 inches.

MIDWEST
Some rain will occur in the far south Midwest. Otherwise, a Canadian high pressure will keep the area cool.

NORTHEAST
High pressure will keep the area dry.