Monday, March 14, 2011

March 14 2011 Forecast Discussion

FORECAST DISCUSSION
Image above is 24 hour 18z GFS Ensembles.
Low pressure system located over Tennessee with strength of 1014 mb makes for a weak SLP (Surface Low Pressure). We will be seeing this air mass wrapping around a mass of pure Gulf air on the right side of this low. With tight isobars surrounding the low, winds are expected to be fairly strong.
These winds should be able to bring a decent warmup to the Southeast as a whole, as the warm air also extends a bit north of this SLP.
Main issue is the cool air mass behind this low pressure system.
The cool air mass has likely been taken from the Arctic masses, and although a somewhat cool air mass continues to support this air mass behind the low, the cool air mass does not seem to be strong enough to provide any strong thunderstorms.
The cool air mass will be supported by a high pressure area, but the cool air mass should subside as the low continues off.
The other possibility is the high moving southward, taking on warm air as the cold air mass retreats.
While a line of rain and embedded storms is likely, the weakness of the low and the only relatively cool air mass on the backside of this low will prohibit severe storms from developing.
However, any storms that do develop will have a risk for some gusty winds.

Elsewhere, SLP over the Rockies should be the same strength as the Southeast low pressure system. This storm, however, will be different. The SLP will be pulling dry, warm air up from the Arizona area. The low will be shooting straight into a relatively neutral air mass.
Precipitation is expected to develop ahead of this low, but with abundance of dry air in the warmer air mass, I don't believe precipitation would be much of an issue. The precipitation would also be in the form of rain.
Main concern with this specific SLP will be how this low should move eastward and bring a strong push of warm air into the Midwest, Northeast.
The dry air should be overcome with humid air.
I would certainly not be surprised to see dew points and RH (Relative Humidity) measurements to greatly increase over the Midwest and Northeast.

That's about it. A new Forecast Discussion will be issued tomorrow.

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