


Quantitative Precipitation Forecast
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Issued by NWS
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964 FOUS30 KWBC 132350 QPFERD Excessive Rainfall Discussion NWS Weather Prediction Center College Park MD 750 PM EDT Sun Jul 13 2025 Day 1 Valid 01Z Mon Jul 14 2025 - 12Z Mon Jul 14 2025 ...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF THE TEXAS, THE OHIO VALLEY, & THE MID-ATLANTIC STATES... ...South-Central Texas... A well-defined MCV, which has occasionally sported an eye feature, is moving by Hamilton TX at the present time. Also present is an upper level low is far southeast NM. Precipitable water values remain north of 1.5", MU CAPE remains 2000-4000 J/kg across the southern third of TX, and effective bulk shear is near 25 kts, but declining as the MCV moves away. The expectation is that a more limited round of convection is possible overnight as a small uptick in the low-level inflow is forecast, which could keep the effective bulk shear close enough, and possibly exceeding, 25 kts so convective organization remains possible. The REFS and HREF have backed off on heavy rain expectations overnight between their last couple cycles, but given the ingredients, a more splotchy and at least semi-organized convective event is possible, perhaps on a smaller scale, overnight. Hourly rain amounts to 2.5" and local amounts to 5" remain possible, which is problematic given the compromised soils across portions of Central and South-Central TX. The guidance and current convective trends no longer supports a Moderate Risk, so it was dropped on this update. However, this environment appears to fit a higher end Slight Risk as the mesoscale guidance sometimes has issues with this environments where convective organization could occur but remains iffy. Higher amounts could be more splotchy overnight than last night/earlier today, depending on convective organization. While there is a bit of uncertainty regarding expected evolution, it remains prudent to keep a higher end Slight Risk going as a precaution. ...New Mexico... Convective organization is expected to continue for several more hours. Pared back the Slight Risk from continuity based on radar reflectivity trends and the latest HREF/REFS guidance. ...Ohio River Valley... Shifted the Slight Risk forward, up the Ohio River Valley, per radar reflectivity trends. See Mesoscale Precipitation Discussion #675 for more details on the short term threat in this area, which is valid through 0410z. This system is expected to have the highest chance of sputtering convection through the overnight hours, so maintained a fairly large Marginal Risk around the Slight to account for this. ...Mid-Atlantic into the Northeast... Kept the Slight Risk going per trends seen in radar reflectivity and signals seen in the 12z AIFS, 18z HREF, and 12z REFS guidance, with activity expected to survive for at least a few hours after sunset. There is some indication that there could be an early morning uptick to activity near the urban centers as well. Available moisture and instability support hourly amounts to 2.5" where cells backbuild, merge, or train. ...Florida... A tropical disturbance east of the state has been drifting southward today. Moisture is high, with precipitable water values above 2", with effective bulk shear roughly 20 kts. HREF and REFS guidance suggest that currently activity could survive until 04-06z before fading. Roth Day 2 Valid 12Z Mon Jul 14 2025 - 12Z Tue Jul 15 2025 ..THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR MUCH OF THE MID-ATLANTIC AND NORTHEAST AS WELL AS THE FLORIDA PENINSULA... ...Mid-Atlantic Through Northeast... There is an overnight threat of thunderstorms tracking across southern portions of the Midwest that could still be going over eastern KY/southern OH early Monday. The Marginal Risk was expanded east through this area to account for this threat. Then, diurnally driven thunderstorms develop ahead of a slow moving cold front over the northern/central Appalachians and track east to the I-95 Northeast urban corridor through the evening. The front is slow to advance because the parent upper low remains stationary into midweek. Broad return flow ahead of the front (SW at 10-15 kts) draws a ribbon of PWs around 2 inches (above the 90th percentile according to NAEFS), sufficient instability (MUCAPE over 1000 J/kg into New England), deep warm cloud depths (above 15,000 ft) and light mean layer flow to support efficient and heavy rain. Rain rates exceeding 2"/hr have a 40-60% probability from the 12Z HREF, especially in the Mid-Atlantic. Guidance today increased the likelihood of heavy rain up through New England, so the Slight Risk was expanded through New Hampshire in coordination with WFOs GYX, ALY, BGM, and PHI. ...Florida... A westward-advancing and deepening mid-level wave approaches the FL peninsula on Monday, providing widespread increasing ascent. In addition to the height falls/PVA accompanying this trough, modest upper diffluence will develop as northerly flow continues, enhancing deep layer lift. This impressive and amplifying ascent will impinge into intensifying thermodynamics with PWs surging above 2.25 inches, or above the 90th percentile according to NAEFS. There continues to be some evolutionary discrepancies among the various models, but in general the setup will be favorable for widespread thunderstorms with heavy rainfall, especially during peak heating when MUCAPE climbs above 2000 J/kg. The heaviest rainfall now looks to develop across central and southern portions of the peninsula. With rainfall rates likely eclipsing 2"/hr, some bulk shear 20-30 kts to help organized convection into clusters, and chaotic/weak storm motions, total rainfall could exceed 3" in places. The inherited SLGT risk was focused just a little. ...Desert Southwest through Texas, the Ozarks and Mid-Mississippi Valley... MCVs and impulses will track along the existing stationary front over the Mid-Miss Valley down to Texas. A very favorable environment remains to support heavy rainfall with PW nearly 2 inches into the Ozarks and above 1" as far as southern Arizona thanks to persistent moist advection out of the Gulf leading to PW anomalies reaching above the 90th percentile locally from West TX into NM and near the Ozarks. These are the locations that may have slightly higher potential for excessive rainfall on Monday, with slow moving storms over West Texas/New Mexico (0-6km mean winds 5 kts or less) and organized convection on 20-30 kts of bulk shear from OK into MO/AR. As of now the Marginal was expanded more over southern Texas given the threat for further overnight activity from central TX. ...Northern Plains... Marginal Risk along Canadian border from MT to MN retained. Potent but positively tilted shortwave will dig out of British Columbia and emerge into a belt of pinched westerlies aligned to the Canada/United States border. This will help elongate a cold front as it drops southward into the Northern Rockies and Northern High Plains, producing locally enhanced ascent across the area. A piece of this vorticity lobe will swing rapidly eastward and interact with the low-level baroclinic zone, which will intensify due to warm advection on an 850mb LLJ surging to 30 kts Monday evening up the Plains, drawing thermodynamics characterized by PWs of 1-1.25 inches and MUCAPE of 1000 J/kg northward. This will support scattered thunderstorms Monday night, and although cells should remain progressive on 0-6km mean winds of 20-25 kts, aligned Corfidi vectors to the mean wind and the front suggests training which could produce 1-2" of rainfall and local FFG exceedance. Jackson/Weiss Day 3 Valid 12Z Tue Jul 15 2025 - 12Z Wed Jul 16 2025 ..THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR THE SOUTHERN FLORIDA PENINSULA AS WELL AS THE UPPER MIDWEST TO CENTRAL GREAT PLAINS... ...Florida... The mid-level wave reaches the Florida Peninsula on Tuesday providing ascent with PWs of 2-2.25 inches collocated with tall skinny cape with MUCAPE above 1000 J/kg. There could also be a surface low (please see NHC guidance) which would additionally enhance ascent. As winds behind the wave turn back to the S/SE across the peninsula, it will likely result in weakly convergent boundaries upon which thunderstorms will blossom and track NW with 2+"/hr rates. Where these cells exhibit even short- term training, especially atop urban areas or across soils moistened from rainfall between now and then, instances of flash flooding could result from 2-3" of rain with locally higher amounts. The Slight Risk for the southern half of the Peninsula remains. ...Northern Rockies through the Upper Midwest... A defined shortwave trough shifts east across MT Tuesday. This will push a cold front, initially aligned generally west-to- east, to become more SW to NE as it approaches the Upper Midwest the latter half of the period. The accompanying ascent (driven by low- level convergence, PVA, and jet- level diffluence) will produce widespread convection on Tuesday areas with PWs above the 90th percentile according to NAEFS. This will support rainfall rates of 1-2"/hr, with training of echoes likely due to boundary parallel mean flow. The greatest potential for heavy rainfall continues to be focused from the eastern Dakotas through northern MN with additional maxes south/southwest across eastern SD to central Nebraska where backbuilding/regenerating cells appear likely. The Slight Risk was expanded over central MN to align with 12Z consensus (that includes the 12Z RRFS and Canadian Regional). ...Northeast, Mid-Atlantic and Southeast... A generally moist and unstable environment will remain across much of the eastern CONUS Tuesday morning as broad ridging expands from the Atlantic. A lingering surface front over southern New England retains an excessive rainfall threat from overnight convection. So a Marginal risk was raised up through Boston. 850mb flow around the offshore ridge will become increasingly S/SE, surging a ribbon of PWs above 2" from the Gulf Coast through the Mid-Atlantic. Although forcing for ascent will be modest, widespread showers and thunderstorms are expected, many of which will have 1-2"/hr rain rates despite their pulse nature. Therefore, the Marginal Risk was maintained for the Mid-Atlantic down to Georgia. ...Mid-Mississippi Valley... Continued risk for MCV coming out from central TX activity looks to push through MO/IL on Tuesday. Elevated moisture and pivoting forcing from associated impulses raise a threat for excessive rain. A Marginal Risk is raised for much of IL, eastern MO into central IN. ...Southwest... Elevated moisture with light steering flow should allow diurnal convection to be locally excessive over the Big Bend of Texas and southeast Arizona. Targeted Marginal Risks were raised for both areas. Jackson/Weiss Day 1 threat area: https://www.wpc.ncep.noaa.gov/qpf/94epoints.txt Day 2 threat area: https://www.wpc.ncep.noaa.gov/qpf/98epoints.txt Day 3 threat area: https://www.wpc.ncep.noaa.gov/qpf/99epoints.txt