Subj : MESO: Nws Weather Prediction Center College Park Md
To   : wx-storm@lists.illinois.edu
From : COD Weather Processor
Date : Fri Jul 18 2025 19:31:29

AWUS01 KWNH 181931
FFGMPD
MDZ000-VAZ000-NCZ000-WVZ000-190130-

Mesoscale Precipitation Discussion 0746
NWS Weather Prediction Center College Park MD
330 PM EDT Fri Jul 18 2025

Areas affected...Central and Southern VA...Northern NC

Concerning...Heavy rainfall...Flash flooding likely

Valid 181930Z - 190130Z

SUMMARY...Strong and locally slow-moving thunderstorms with very
heavy rainfall rates are expected across large areas of central to
southern VA and northern NC by later this afternoon and continuing
into the evening hours.

DISCUSSION...The latest GOES-E visible satellite imagery shows
convective initiation taking place across areas of central to
southern VA and northern NC. An increasingly agitated CU field is
noted near and to the south of a quasi-stationary front draped
across the region, and LightningCast data is suggestive of
multiple areas of thunderstorm activity that will soon be
expanding in coverage, including the I-64 corridor from near
Richmond on down through the Hampton Roads/Norfolk area, and
adjacent areas of northeast NC.

A substantial amount of moisture and instability is pooled along
and south of this front, with PWs of 1.5 to 2 standard deviations
above normal, and MLCAPE values of 2500 to 3500 J/kg. This will
support convective cores with very high rainfall rates that will
be capable of reaching 2 to 4 inches/hour which is strongly
supported by a consensus of the 12Z HREF and 06Z REFS guidance.

Some of the thunderstorms will be capable of growing upscale into
some semi-organized convective clusters over the next several
hours, and this will especially be the case over central to
southeast VA where stronger frontal convergence and closer
proximity to some stronger shear profiles will be noted.

Localized cell-merger and cell-training activity is expected, and
some spotty rainfall amounts by mid-evening may reach 3 to 5
inches. A combination of these heavier rainfall totals along with
locally wet antecedent conditions and urban sensitivities will
likely result in scattered to numerous areas of flash flooding.
This will include concerns for locally dangerous urban flash
flooding impacts.

Orrison

....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!=
DZ3fjg!6Zb3n8gbOMrXG2RHnQpd7vwbdft2TTJviYxpNgS43J77Ry_YhTtNwGXZ736jqo9TRm2g=
Js269-IolDYX5OLLWs3DN2Q$  for graphic product...

ATTN...WFO...AKQ...GSP...LWX...MHX...RAH...RNK...

ATTN...RFC...ALR...ORN...RHA...TIR...NWC...

LAT...LON   39307756 38427676 37107609 36067552 35677544=20
            35187621 35417798 35877977 35858094 36028181=20
            36498158 37568003 38517909 39267855=20

=3D =3D =3D
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