542 FOUS30 KWBC 150042 QPFERD Excessive Rainfall Discussion NWS Weather Prediction Center College Park MD 842 PM EDT Wed Oct 14 2026 Day 1 Valid 01Z Thu Oct 15 2026 - 12Z Thu Oct 15 2026 ...THERE IS A MODERATE RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF OKLAHOMA INTO THE RED RIVER VALLEY OF TEXAS... ...16Z and 01Z Updates... The prior forecast reasoning remains on track with the approach of the upper low and analyzed cold front through northern Oklahoma into the Texas Panhandle. Minimal ERO were made at 01Z, mainly to trim both the Slight and Marginal Risk areas, now north of the surface cold front, across the OH Valley. An anomalously moist environment is in place along and ahead of the front with plentiful Gulf moisture and influence from Simon in the Pacific leading to PWATs near/at or even past record breaking levels for the month of October. The 2.23 in PWAT value indicated by the 12Z OUN sounding is the highest recorded for October during the period of record. Storms overnight which continue this morning have already lead to several inches of rainfall, particularly from central Oklahoma west-southwest into the southeastern Texas Panhandle where areal average estimated rainfall totals per MRMS data are in the 3 to 4" range (locally 6-8" to the west of Oklahoma City). Expect a lull in activity as the overnight low-level jet continues to wind down and before renewed surface heating leads to higher instability later this afternoon. The latest surface observations indicate an outflow boundary through southern Oklahoma which leads to some uncertainty with the northward extent of the threat, though expect most of this region to recover as storms wind down into the early afternoon in combination with daytime heating, as well as when the low-level flow ramps up again into the overnight hours helping to draw higher theta-e air back further north ahead of the approaching dry line/Pacific front. There is some uncertainty with westward extent when combining the HREF/RRFS deterministic amounts and ensemble probabilities, with the RRFS favoring a bit more of a southwesterly axis in terms of additional rainfall which makes sense given the airmass may not fully recover as far north as the observed west- southwesterly axis overnight. However, there is growing concern of potentially higher impact flash flooding over portions of central Oklahoma around the greater Oklahoma City metropolitan area and just to the west along I-40. The best overlap in the high-res guidance for higher rainfall totals is through this region (moderate to high HREF and RRFS probabilities of >5"), and some of the heaviest rainfall overnight into this morning was observed in the I-40 vicinity just to the west of Oklahoma City (estimates of over 8"). Hurley/Putnam Day 2 Valid 12Z Thu Oct 15 2026 - 12Z Fri Oct 16 2026 ...THERE IS A MODERATE RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF WEST TEXAS... ...2030Z Update... A targeted Moderate Risk has been introduced for portions of west Texas from just east of Big Bend along the Rio Grande and across the Stockton Plateau to the Pecos River Valley and north to just past the I-10 corridor. As previously noted, this region will see a more favorable set up for longer duration, heavy rainfall as the progression of the cold front slows and becomes more ENE to WSW oriented ahead of a surface wave compared to the faster eastward progression of the front to the north, preserving the warm sector through most of the day 2 period. An axis of higher Gulf moisture and instability as well as stronger southerly low-level flow will be in place through the day and into the evening/early overnight hours, intersecting the front as it pushes southward towards the I-10 corridor. Storms are expected to initiate both along/ahead of the front and within the instability axis Thursday afternoon and last through the cold front passage, not expected until at least the early hours of Friday morning. The anomalously high moisture will support efficient downpours with these storms, with rainfall rates of 2"+ per hour possible. The latest deterministic hi-res guidance shows the potential for locally heavy totals as much as 6-7", and HREF/RRFS guidance both show high probabilities (70-90%) of totals exceeding 3" and at least moderate (40-60%) probabilities of totals exceeding 5". One caveat to the overall threat will be the speed of the cold front. If the front happens to be faster than currently progged, this would limit the duration of the heavy rainfall and thus flash flood threat. However, felt there was enough consistency in the forecast and confidence from the latest 12Z guidance for the upgrade. The Slight Risk northeastward through Texas to south-central Oklahoma was also adjusted a bit to the southeast based on the 12Z hi-res guidance. Otherwise, minimal other changes were needed to the inherited outlook other than trimming some of the northern extent of the Marginal Risk through the Midwest based on the latest forecast frontal position through the day 2 period. Putnam ...Previous Discussion... Complex upper level evolution across the northern half of the CONUS will lead to our first strong cold front of the season being propelled rapidly to the south Thursday evening as diurnal mixing ceases near sunset and the front faces little resistance on its push southward. The upper level setup over the Southeast CONUS will still be in position to provide a continued draw of rich theta_E air out of the Gulf into the Southern Plains ahead of the front meaning the convergence signature and prospects for heavy rainfall will continue for those along and ahead of the front. The greatest potential for heavy rain will exist over the Southern High Plains into southwestern TX as they will be the last places to see the frontal passage at any point in the forecast period with areas of the Big Bend and Lower Trans Pecos likely to not see the front until perhaps after the D2 time frame. General instability maximum and PWAT anomalies up near +3 standard deviations correlate to heavy thunderstorm prospects over the Southern High Plains with a corridor of significant rainfall potential from the Western Rolling Hills of TX, through the Permian Basin and Concho Valley, down into the Big Bend area and over into the terrain of southwest TX. Some added isentropic ascent will lead to prolonged periods of heavy rain, even after the front passes until a more robust dry air advection regime takes shape beyond the current D3. Ensembles continue to trend towards an area of appreciable rainfall, especially south of the Pecos River in west TX where the greatest instability axis is located, along with substantially high PWATs running between 1.5-2", a signal that would easily encroach on the 95-99th percentile according to the latest NAEFS and ECENS climatological percentiles. Forecast total remain prolific for this area of the CONUS with guidance inferring on a broad area of at least 2-4", locally higher, across portions of west TX with the max focused over the Stockton Plateau towards the RGV within the Big Bend. This setup resembles some of the more prominent heavy rain depictions for west TX as the combination of pre-frontal convection and then prolonged isentropically forced precipitation will account for a cumulative effect, leading to such a robust QPF depiction. This is trending towards a formidable setup for this area of the CONUS with a high- end SLGT remaining the forecast over the above areas. There is a potential for an upgrade in the risk further as the the progged cold front will play a significant role in the potential, thus will need to evaluate any timing differences in the latitudinal push of the front itself. For now, a pretty high likelihood of at least scattered flash flood prospects within the Stockton Plateau to Big Bend area with outside chances for more appreciable flash flooding in the areas of both Midland/Odessa over into San Angelo. The previous SLGT was adjusted a bit further north to encompass southern OK to account for lingering flash flood chances beyond the main impacts from the now D1. Kleebauer Day 3 Valid 12Z Fri Oct 16 2026 - 12Z Sat Oct 17 2026 The probability of rainfall exceeding flash flood guidance is less than 5 percent. Putnam Day 4 and Day 5 Valid 12Z Sat Oct 17 2026 - 12Z Mon Oct 19 2026 ...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS PARTS OF SOUTHEAST FLORIDA SATURDAY... ...2030Z Update... The prior forecast remains on track as little to no changes were needed to the inherited Outlooks. Hurley ...Previous Discussion... A well defined cold front is expected to press southward Saturday across central to south Florida, becoming stationary across South FLorida on Sunday. Low level east northeasterly flow will strengthen into the east coast Florida in the wake of this front on Saturday and remain strong through Sunday. PW values in this strengthening low level east northeasterly flow are expected to remain above average, 1.5 to 2+ standard deviations above the mean. Strong boundary layer convergence maxima likely along the east central coast of Florida. This will support potential for locally heavy rains from well defined rain bands that may train for a period both Saturday and Sunday, with isolated runoff issues possible along the east central coast of Florida, especially in urbanized regions. Oravec 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 $$