606
FXUS21 KWNC 141813
PMDTHR
US HAZARDS OUTLOOK
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
300 PM EDT OCTOBER 14 2026
SYNOPSIS: MULTIPLE MODELS DEPICT A ROBUST STORM DEVELOPING IN THE LEE OF THE
ROCKIES LATE IN WEEK-1 WHICH HAS THE POTENTIAL TO DROP HEAVY PRECIPITATION ON
MUCH OF THE PLAINS AND MISSISSIPPI VALLEY EARLY IN WEEK-2, ESPECIALLY IN
SOUTHERN PARTS OF THE REGION. FARTHER WEST, PRECIPITATION FROM THIS STORM IS
EXPECTED TO COINCIDE WITH BELOW-NORMAL TEMPERATURES, INCREASING THE POTENTIAL
FOR HEAVY SNOW ACROSS MUCH OF THE ROCKIES, ESPECIALLY THE HIGHER ELEVATIONS. AS
THIS SYSTEM FORMS AND PUSHES EASTWARD, PERIODS OF HIGH WINDS ARE POSSIBLE OVER
A LARGE PART OF THE CENTRAL CONTIGUOUS U.S. (CONUS).
HAZARDS
MODERATE RISK OF HEAVY PRECIPITATION FOR PORTIONS OF THE SOUTHERN PLAINS AND
LOWER MISSISSIPPI VALLEY, THU, OCT 22.
SLIGHT RISK OF HEAVY PRECIPITATION FOR CENTRAL AND SOUTHERN SECTIONS OF THE
PLAINS AND MISSISSIPPI VALLEY, THU-SAT, OCT 22-24.
SLIGHT RISK OF HIGH WINDS FOR MOST OF THE PLAINS AND MISSISSIPPI VALLEY,
THU-FRI, OCT 22-23.
SLIGHT RISK OF HEAVY SNOW FOR MUCH OF THE NORTHERN AND CENTRAL ROCKIES,
THU-FRI, OCT 22-23.
DETAILED SUMMARY
FOR SATURDAY OCTOBER 17 - WEDNESDAY OCTOBER 21:
HTTPS://WWW.WPC.NCEP.NOAA.GOV/THREATS/THREATS.PHP
FOR THURSDAY OCTOBER 22 - WEDNESDAY OCTOBER 28: MODELS CONTINUE TO DEPICT A
500-HPA TROUGH OVER OR NEAR THE SOUTHWESTERN CONUS, WHICH IS EXPECTED TO INDUCE
LEE CYCLOGENESISPLAINS STARTING LATE IN THE WEEK-1 PERIOD AND CONTINUING FOR
THE FIRST FEW DAYS OF WEEK-2. THIS SYSTEM HAS THE POTENTIAL TO BRING A VARIETY
OF HAZARDS TO LARGE PORTIONS OF THE CENTRAL CONUS. THERE IS LESS MODEL
AGREEMENT ON THE DETAILS OF THIS SCENARIO COMPARED TO YESTERDAY, WITH THE
EUROPEAN ENSEMBLE (ECENS) MEAN INDICATING SOMEWHAT LOWER CHANCES FOR HEAVY
PRECIPITATION IN THE SOUTHERN GREAT PLAINS COMPARED TO YESTERDAY AND FOCUSING
THE LARGEST AMOUNTS FARTHER WEST ACROSS OKLAHOMA AND TEXAS. THE EUROPEAN
ARTIFICIAL INTELLIGENCE FORECAST SYSTEM (ECMWF-AIFS) SIMILARLY REDUCES THE ODDS
OF HEAVY TO EXCESSIVE PRECIPITATION ACROSS THE PLAINS. THE DYNAMICAL EUROPEAN
MODEL (ECMWF) STILL BRINGS AREAS OF HEAVY TO EXCESSIVE RAIN TO THE SOUTHERN
PLAINS, BUT THE EVOLUTION IS A LITTLE SLOWER AND THE LARGEST AMOUNTS (1.5 TO 3
INCHES IN 48 HOURS) ARE NOT AS WIDESPREAD AS YESTERDAY. IN CONTRAST, THE
DYNAMICAL GFS-AI SHOWS HEAVY TO EXCESSIVE AMOUNTS ACCOMPANYING THE STORM
SYSTEM, BUT FOCUSES THE HEAVIEST PRECIPITATION (3-DAY TOTALS OF 5-8 INCHES)
FARTHER WEST ACROSS OKLAHOMA. MEANWHILE, THE CANADIAN ENSEMBLE (CMCE) IS
CONSISTENT WITH ITS EARLIER SOLUTIONS, SHOWING LOW TO MODERATE CHANCES FOR
HEAVY PRECIPITATION ACROSS THE REGION. THE PROBABILISTIC EXTREMES TOOLS (PETS)
FROM THE 0Z GEFS, ECENS, AND CMCE ARE MORE CONSISTENT, ALL HIGHLIGHTING AN AREA
WHERE 3-DAY TOTALS TOP THE 85TH CLIMATOLOGICAL PERCENTILE AND 1 INCH ACROSS THE
SOUTHERN TO CENTRAL GREAT PLAINS AND ADJACENT LOWER MISSISSIPPI VALLEY. DESPITE
CONSIDERABLE UNCERTAINTY, A PREPONDERANCE OF THE TOOLS SUPPORT A MODERATE RISK
(40-60% CHANCE) OF HEAVY PRECIPITATION DAY 8 (OCT 22) WHERE THE PETS ARE IN
BEST AGREEMENT AND MANY MODELS DEPICT MODERATE TO HEAVY AMOUNTS, WITH SOME
EXPANSION TO THE WEST TO MATCH THE WESTWARD SHIFT IN SOME MODELS. THEREAFTER,
THE TOOLS ARE TOO INCONSISTENT TO JUSTIFY ANY MODERATE RISK, BUT GUIDANCE
GENERALLY AGREES THAT ENHANCED PRECIPITATION IS LIKELY TO FALL SOMEWHERE ACROSS
A BROAD PART OF THE CENTRAL CONUS. MOST TOOLS SHOW PARTS OF THIS AREA BEING
AFFECTED BY THE STORM SYSTEM, BUT THERE IS SIGNIFICANT UNCERTAINTY REGARDING
LOCATIONS AND TIMING. WITH SOME TOOLS SHOWING A SLIGHTLY SLOWER EVOLUTION
COMPARED TO YESTERDAY, THE SLIGHT RISK IS EXTENDED AN ADDITIONAL DAY, THROUGH
OCT 24 (DAY 10). NO AREAS ARE CURRENTLY DEPICTED WITH ENHANCED CHANCES FOR
WIDESPREAD PROLONGED FLOODING, BUT LOCALIZED FLASH FLOODING IS POSSIBLE IN ANY
AREAS THAT RECEIVE HEAVY TO EXCESSIVE RAINS.
MODEL SOLUTIONS SPIN UP THE SURFACE LOW VERY CLOSE TO THE FRONT RANGE OF THE
ROCKIES, FAVORING UNSETTLED WEATHER ALONG THE NORTHERN AND CENTRAL ROCKIES
BEFORE THE SYSTEM MOVES AWAY FROM THE MOUNTAINS, ALONG WITH BELOW NORMAL
TEMPERATURES. MEANWHILE, CONTINUED TROPICAL CYCLONE (TC) ACTIVITY IN THE
EASTERN NORTH PACIFIC HAS THE POTENTIAL TO BRING TROPICAL MOISTURE NORTHWARD
INTO THE WESTERN CONUS. THIS SET-UP ENHANCES THE POTENTIAL FOR HEAVY SNOW
ACROSS MUCH OF THE ROCKIES, PARTICULARLY THE HIGHER ELEVATIONS. MODEL FORECASTS
ARE LESS ROBUST WITH THIS EVENT THAN YESTERDAY OVERALL, BUT MOST BRING
SIGNIFICANT ACCUMULATING SNOW TO THE REGION EARLY WEEK-2, AND THE DYNAMICAL
ECMWF SHOWS 48-HOUR TOTALS EXCEEDING 10 INCHES IN ISOLATED HIGHER ELEVATIONS
MAINLY ACROSS SOUTHERN COLORADO AND NORTHEASTERN UTAH. DESPITE SOME
INCONSISTENCIES OF AMOUNTS AND TIMING, TOOLS SUPPORT A SLIGHT RISK FOR HEAVY
SNOW ACROSS THE CENTRAL ROCKIES AND ADJACENT AREAS DAYS 8-9 (OCT 22-23) BEFORE
THE STORM SYSTEM BEGINS TO PULL EASTWARD. THIS IS ONE DAY BEYOND THE HEAVY SNOW
HAZARD POSTED YESTERDAY, CONSISTENT WITH THE SOMEWHAT SLOWER PROGRESSION OF THE
STORM SYSTEM SHOWN BY MOST MODELS TODAY.
SURFACE PRESSURE GRADIENTS ASSOCIATED WITH THIS SYSTEM START OFF QUITE STRONG,
FAVORING ENHANCED WINDS OVER MUCH OF THE COUNTRY'S MIDSECTION. THE PET FROM THE
ECENS REFLECTS THIS, INDICATING AT LEAST A 20% CHANCE OF 3-DAY MAXIMUM WINDS
EXCEEDING THE 85TH PERCENTILE OVER PORTIONS OF THE NORTH-CENTRAL CONUS EARLY IN
THE FORECAST PERIOD, WITH ISOLATED AREAS EXCEEDING 25 MPH. THE GEFS PET IS NOT
AS ROBUST, BACKING OFF THE ENHANCED CHANCES FOR HIGH WINDS DEPICTED YESTERDAY.
AMONG THE DYNAMICAL MODELS AND ENSEMBLE MEANS, MOST SHOW AT LEAST BRIEF PERIODS
WITH WIND GUSTS NEAR TROPICAL STORM FORCE OVER PARTS OF THE PLAINS AND ADJACENT
AREAS, BUT THERE IS A GREAT DEAL OF UNCERTAINTY REGARDING THE TIMING AND
LOCATION OF HIGH WINDS. GIVEN THE REDUCED AND LESS CONSISTENT GUIDANCE COMPARED
TO YESTERDAY, A BROAD AREA IS HIGHLIGHTED WITH A SLIGHT RISK OF HIGH WINDS IS
POSTED FOR DAYS 8-9 (OCT 22-23) FROM THE FRONT RANGE THROUGH PORTIONS OF THE
MISSISSIPPI VALLEY, BASED ON PATTERN RECOGNITION, AND WHERE TOOLS MODESTLY
HIGHLIGHT INCREASED CHANCES FOR HIGH WINDS AT CERTAIN LOCATIONS AND TIMES. THE
RISK DECLINES AS THE SURFACE SYSTEM PULLS EASTWARD.
MODEL SOLUTIONS DEPICT PERSISTENT TROUGHING AT THE SURFACE AND ALOFT OVER
ALASKA AND ADJACENT AREAS THROUGH MUCH OF THE FORECAST PERIOD. STRONG WINDS AND
HEAVY PRECIPITATION ARE EXPECTED TO AFFECT SOUTH-CENTRAL AND SOUTHEAST ALASKA
AT TIMES, BUT STORMY WEATHER IS NOT UNUSUAL IN THESE AREAS DURING EARLY AUTUMN,
AND NORMAL PRECIPITATION APPROACHES ONE INCH PER DAY IN A FEW SPOTS. SINCE
HAZARDS THRESHOLDS ARE NOT LIKELY TO BE EXCEEDED, NO ASSOCIATED HAZARDS ARE
POSTED AT THIS TIME FOR ALASKA.
FORECASTER: RICH TINKER
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