Subj : HVYRAIN: Excessive Rainfa
To   : All
From : Mike Powell
Date : Tue Feb 18 2025 08:21:00

FOUS30 KWBC 180801
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
301 AM EST Tue Feb 18 2025

Day 1
Valid 12Z Tue Feb 18 2025 - 12Z Wed Feb 19 2025

....THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ALONG PORTIONS OF
THE CENTRAL GULF COAST...

Strengthening southwesterly return flow from the Gulf ahead of an 
amplifying upper-level shortwave and an associated surface cold 
front are expected to draw deeper moisture into portions of the
central Gulf Coast with PWs climbing to 1.5"+. This moisture, 
along with increasing lift (via right-entrance region of 120+ kt
subtropical jet streak) and marginal instability (MU CAPE rising to
near 500 J/kg right along the immediate coast) are likely to be
sufficient for a relatively short period of heavy rainfall rates
(concentrated between 00-09z, and lasting for around 3 hours total
at any one locality). While the potential for training storms looks
relatively low (with instability largely lacking prior to the
arrival of the progressive storms along the front), chances for any
isolated flash flooding appear maximized in the vicinity of Lake
Charles (with the best instability resulting in highest odds for
1-2"/hr rainfall rates, and localized totals of 2-4" over a 3-hr
period). Elsewhere (and particularly farther north from the
immediate coastline) rates will likely struggle to surpass 1"/hr
with a lack of instability, though in some places these brief
downpours may be enough to cause localized excessive rainfall
(particularly into portions of east-central TX and west-central LA
where antecedent conditions are wetter, especially compared to
relatively dry antecedent conditions in south-central LA). 

Churchill


Day 2
Valid 12Z Wed Feb 19 2025 - 12Z Thu Feb 20 2025

The probability of rainfall exceeding flash flood guidance is less
than 5 percent. 

Churchill


Day 3
Valid 12Z Thu Feb 20 2025 - 12Z Fri Feb 21 2025

The probability of rainfall exceeding flash flood guidance is less
than 5 percent. 

Churchill

$$
--- SBBSecho 3.20-Linux
 * Origin: ILink: CCO - capitolcityonline.net (454:3/105)

.