Severe Weather Center

Current Severe Weather Discussion Issued by the Storm Prediction Center

   SPC AC 071630

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1130 AM CDT Sat Jun 07 2025

   Valid 071630Z - 081200Z

   ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS
   AFTERNOON/EVENING FROM NORTHERN MISSISSIPPI TO NORTH GEORGIA...

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
   THE SOUTHEAST AND THE SOUTHERN HIGH PLAINS...

   ...SUMMARY...
   An organized/bowing line of storms will move across northern
   Mississippi/Alabama/Georgia through this evening with the potential
   for corridors of wind damage.  Other areas of severe storms will be
   possible in the wake of this morning's storms from Mississippi
   westward to north Texas, and across parts of west Texas and the
   southern High Plains.

   ...Mid-South into the Southeast through tonight...
   Ahead of a midlevel shortwave trough over the lower MO Valley, an
   MCS and associated MCV are moving eastward across the Mid-South. 
   Per modified 12z soundings, as surface temperatures warm into the
   80s, MLCAPE will exceed 2000 J/kg in an environment with sufficient
   downdraft potential and low-midlevel vertical shear to maintain a
   wind-damage threat through the afternoon from northern MS/adjacent
   TN across AL to GA.  Please see MD 1175 for additional short-term
   details.  Otherwise, the MCS is expected to weaken late this
   evening/early tonight while moving into SC.  

   In the wake of the morning convection, some additional storm
   development will be possible along the trailing outflow/effective
   front from north TX across southern AR into MS/AL.  The specific
   corridor will depend on the southern extent of the outflow
   progression with today's MCS, but some hail/wind threat will be
   possible later this afternoon into tonight.

   ...Northeast NM into the northern TX Panhandle this evening...
   Low-level flow will become upslope this afternoon, when surface
   heating and low-level moisture could be sufficient for isolated
   thunderstorm development near the Raton Mesa in far northeast NM. 
   There is the potential for a sustained supercell to emerge from
   initially high-based convection, and then move southeastward into
   the northwest TX Panhandle this evening.  Moderate buoyancy (MLCAPE
   of 1000-1500 J/kg), relatively straight hodographs with effective
   bulk shear near or above 40 kt and midlevel lapse rates of 7-8 C/km
   will support the primary threats of large hail and strong-severe
   outflow gusts for a few hours this evening.

   ...Permian Basin this afternoon/evening...
   The 12z MAF sounding revealed a warm elevated mixed layer and a
   strong cap.  Surface heating/mixing along and south of an outflow
   boundary could be sufficient to support isolated thunderstorm
   development later this afternoon/evening, though confidence is low. 
   If storms form, the environment will support splitting supercells
   capable of producing isolated large hail and damaging outflow gusts
   for a few hours this evening.  This area will be re-evaluated for a
   possible upgrade at 20z.

   ...Mid MS/lower OH Valleys this afternoon/evening...
   As the midlevel shortwave trough progresses east-southeastward from
   northwest MO vicinity as of mid morning, there will be the potential
   for a short arc of thunderstorms near and immediately southeast of
   the midlevel vorticity center.  Boundary-layer dewpoints remain in
   the 60s ahead of this feature, and there will be some increase in
   vertical shear as the midlevel trough approaches.  However, fairly
   widespread clouds, poor midlevel lapse rates and the influence of
   the MCS farther south all suggest that the severe threat is best
   characterized as marginal.

   ...Northern Plains this afternoon/evening...
   A cold front will surge southeastward across ND this afternoon, in
   association with a digging shortwave trough now over southern SK. 
   Pre-frontal low-level moisture and buoyancy will likely remain
   rather limited this afternoon, but a band of convection is expected
   along the front this afternoon.  Gusty outflow winds and some hail
   may occur with the strongest storms for a few hours this
   afternoon/evening.

   ..Thompson/Supinie.. 06/07/2025

   CLICK TO GET <a href="/products/outlook/archive/2025/KWNSPTSDY1_202506071630.txt">WUUS01 PTSDY1</a> PRODUCT

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 2000Z
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Current Excessive Rainfall Discussion Issued by the Weather Prediction Center

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
1120 AM EDT Sat Jun 7 2025
Day 1
Valid 16Z Sat Jun 07 2025 - 12Z Sun Jun 08 2025

...THERE IS A RISK OF EXCESSIVE RAINFALL ACROSS MUCH OF THE EASTERN
UNITED STATES...WITH SLIGHT RISKS IN SOUTHERN NEW ENGLAND... THE
OHIO RIVER VALLEY...AND MID-SOUTH...

An active day of heavy rainfall and flash flooding is expected
across a large portion of the eastern United States, with the
Marginal Risk area now encompassing the majority of the land area
in the CONUS east of 95W longitude. This is due to a broad region
of near to above normal tropospheric moisture (via PW anomalies)
and sufficient instability for convective rain bands and
thunderstorms.

Generally, the broad zone of heavy rainfall risk can be divided
into three main areas of concern, all indicated by a regional-scale
Slight Risk maximum now:

1. In the Northeast, where low-topped convection has organized into
narrow bands of efficient heavy rainfall. MRMS analysis indicates
almost no ice present in these convective bands, with 30 dBZ echo
tops generally shy of the -10C level. In other words, warm rain
processes are dominant and any organized convective rain band could
produce localized heavy rainfall. The area of greatest concern is
probably from active area of flash flooding in the Hudson Valley
near Albany, NY eastward through Massachusetts and northern
Connecticut to the Boston metro area. There should naturally be
increasing low-level convergence with the existing front draped
across the region, and increasing easterly flow near the coast
around the north side of the offshore low. Aloft, a coupled jet
structure should lead to enough divergence to focus convection.

2. The Ohio River Valley region, particularly the middle and upper
Ohio Valley from late this afternoon well into the overnight hours.
This will be due to scattered convective rain bands and perhaps
some thunderstorms developing in advance of an eastward propagating
mid-upper level wave, and developing surface low by this afternoon,
currently centered over IA- MO. This should allow for some
organized convective bands in the warm air advection regime. Model
forecast soundings show increasing PWs to near or above the 90th
percentile for early June and tall, skinny CAPE profiles that are a
good match for efficient, low-topped convective flash flood events.
Of particular concern will be the potential for flash flooding
overnight in the central Appalachian region from eastern Kentucky
and southeast Ohio into West Virginia and southwest Pennsylvania.
Models show southwest low-level inflow increasing into the
mountains in a very moist environment, with the right entrance
region of an upper level jet streak providing divergence aloft. All
of this should support an organized heavy rain threat and the
structure of the instability profile will keep convection low-
topped and dominated by warm rain processes. Locally significant
flash flooding will be possible given the terrain in the area and
relatively wet antecedent conditions.

3. Across the mid-South where a forward propagating MCS has already
generated some flash flooding in central Arkansas, but appears to
begin accelerating. Renewed development and/or stalling and
training will be possible along the southern periphery of the cold
pool later today, and hi-res models do show localized corridors of
heavy rainfall that would be sufficient to cause flash flooding.
The Slight Risk was shifted south to account for observational
trends indicating the current position of the cold pool and
convective line, and the projected motion over the next few
hours.

Lamers


Day 1 threat area: <a href="https://www.wpc.ncep.noaa.gov/qpf/94epoints.txt"<u>www.wpc.ncep.noaa.gov/qpf/94epoints.txt</u></a>