Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Tallahassee Florida
644 am EDT Tuesday Mar 31 2015
[through 12z wednesday]... visibilities have been up and down for
the past few hours. Currently all terminals are LIFR or IFR. Expect
conditions to improve to VFR after 15z. Thunderstorms are possibleat
dhn, aby, tlh and vld this afternoon. Included tempo groups
between 18 and 23z to account for brief gusty winds and reduced
visibility in those storms. Fog and low ceilings will return after 06z
with MVFR expected.
Previous discussion [319 am edt]...
Near term [through today]...
Similar to yesterday, we are again under a marginal risk from Storm Prediction Center. A
short wave will approach from the west and will interact with a
front stalled across middle Alabama and Georgia. While the
thermodynamic environment will support severe storms, the forcing
will depend on the strength of the short wave. Models show steep
lapse rates and about 1700 j/kg of cape. This combined with daytime
heating will create the potential for isolated strong to severe
storms. Again, the main concerns will be strong winds and hail. Rain
chances will range from 40 in southwest Georgia to 20 near the
coast. High temperatures will be near 80.
Short term [tonight through thursday]...
A short wave ridge will develop over the southeast Wednesday.
However...a quasi-stationary front...oriented southeast to
northwest across central Georgia...may still serve as a focus for
isolated showers and thunderstorms Wednesday afternoon. Though
the 0-6 km bulk shear magnitude appears weaker than what observed
on Monday...the persistent elevated mixed layer (that originated
in the northern Mexican plateau) will continue to pose at least
some threat for small to marginally severe hail and gusty winds. A
weak short wave trough will translate across the southeast on
Thursday...but weak forcing and poor thermodynamics (including
much less impressive middle-layer lapse rates) will limit deep moist
convection to isolated coverage. Temperatures will be above
Long term [thursday night through tuesday]...
A long wave trough and associated surface cold front will pass
through our forecast area this weekend...brining slightly cooler
and much drier air to the region into the next work week. Both the
00 UTC GFS and European model (ecmwf) forecast this front to lose much of its deep
layer moisture as it passes through Saturday morning...so rain
chances will be slight. Temperatures will remain above average
through Saturday morning...then begin to cool behind the cold
front. Highs on Saturday and Sunday will be in the middle 70s...with
lows Sunday morning in the upper 40s to lower 50s. Temperatures
will rebound to slighty above average early next week.
Relatively light southwest winds will increase to moderate levels
this afternoon and evening...then subside overnight. A similar
trend is likely Wednesday...though winds will not increase quite
as much in the afternoon. Winds will become southeast on Thursday
as a high pressure system moves east off the Atlantic coast.
Relative humidity will remain above critical values. On Wednesday
dispersion values will be high in parts of the Florida Panhandle and
Big Bend. No red flag concerns.
Rivers will continue to slowly fall over the next few days as
widespread heavy rainfall is not expected.
Preliminary point temps/pops...
Tallahassee 82 62 82 60 82 / 30 20 20 20 10
Panama City 75 65 75 62 76 / 10 10 10 10 10
Dothan 81 61 80 59 81 / 30 20 30 20 20
Albany 80 60 81 59 80 / 40 40 30 20 20
Valdosta 81 61 81 59 80 / 30 30 30 20 30
Cross City 81 62 81 59 82 / 20 10 20 10 30
Apalachicola 76 65 77 62 76 / 10 10 10 10 10
Florida...dense fog advisory until 10 am EDT /9 am CDT/ this morning for
Calhoun-central Walton-coastal Bay-coastal Dixie-coastal
Franklin-coastal Gulf-coastal Jefferson-coastal Taylor-
coastal Wakulla-Gadsden-Holmes-inland Bay-inland Dixie-
inland Franklin-inland Gulf-inland Jefferson-inland Taylor-
Georgia...dense fog advisory until 10 am EDT this morning for Baker-Ben
Alabama...dense fog advisory until 9 am CDT this morning for Coffee-Dale-