Thursday, March 17, 2011

March 17 Severe Weather Forecast Discussion

This is a Forecast Discussion about a potential severe weather situation in in next week's midweek.

Enough energy may be available Monday-Tuesday so that strong storms may develop. Possibly in the form of a squall line.

A measure of the lifted index is a measure to tell how unstable the atmosphere may be. When the Lifted Index goes below 0, that is when instability begins to develop in the atmosphere.
Below is the most recent image from the 12z GFS image.
Based on this image, some instability will be in a formation that appears suitable for a squall line. At this time, The Weather Centre is not very concerned with this severe weather event, but we will definitely watch this situation.

CAPE is a measure of instability in the atmosphere. When levels go above 2000 j/kg, it is a sign of developing instability in the atmosphere. Below is the latest image in the 12z GFS.
CAPE values also show the prospect of a fairly weak squall line that may begin to dissipate as it moves east.

Humidity can play a big factor in the severe thunderstorm. Humidity is supplied by the Gulf of Mexico. The image below details the humidity values expected in the air.
This image definitely shows fairly high values of humidity in the range of potential severe weather. The Weather Centre will issue a map on this potential outbreak.