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FXUS07 KWBC 311900
PMD30D
PROGNOSTIC DISCUSSION FOR MONTHLY OUTLOOK
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
300 PM EDT THU OCT 31 2024
30-DAY OUTLOOK DISCUSSION FOR NOVEMBER 2024
THE UPDATED NOVEMBER 2024 TEMPERATURE AND PRECIPITATION OUTLOOK IS ADJUSTED BY
THE AVAILABILITY OF MEDIUM- AND EXTENDED-RANGE FORECAST MODEL GUIDANCE WITHIN
THE VALIDATION PERIOD (I.E. FIRST 2 WEEKS OF OCTOBER) AND THE MOST RECENT
AVAILABLE SUBSEASONAL FORECAST MODEL GUIDANCE FOR THE LATTER HALF OF NOVEMBER.
ADDITIONALLY, THE LATEST STATUS OF ENSO AND THE MJO WERE ALSO CONSIDERED. THE
LAGGED IMPACTS OF THE MJO RESULTED IN MODERATED PROBABILITIES ACROSS MUCH OF
THE FORECAST DOMAIN, AS IT IS LARGELY OUT OF PHASE WITH MUCH OF THE DYNAMICAL
MODEL GUIDANCE LATER IN THE MONTH.
THE TEMPERATURE GUIDANCE FOR EARLY NOVEMBER REFLECTS AN EARLY MONTH COLD PERIOD
ACROSS THE WESTERN CONUS. THE EARLY COOL PERIOD IS BALANCED BY SOME GUIDANCE
FOR LATER IN NOVEMBER THAT REFLECTS A MODERATION. MJO RELATED CIRCULATION
CHANGES, BASED ON LAGGED COMPOSITES FROM A PHASE 7 MJO, WOULD FAVOR WARMER
SOLUTIONS ACROSS THE WEST AND COOLER SOLUTIONS IN THE EASTERN CONUS. THE
UNCERTAINTY FROM THE DISAGREEMENT RESULTS IN EQUAL CHANCES OF ABOVE-, NEAR-, OR
BELOW-NORMAL TEMPERATURES FROM THE WEST COAST TO THE ROCKIES. ACROSS THE
EASTERN CONUS, AN EARLY WARM PERIOD FOLLOWED BY PREDICTED ABOVE-NORMAL
TEMPERATURES FOR THE REST OF THE MONTH ARE MITIGATED BY THE POTENTIAL FOR
SUB-MONTHLY VARIABILITY AND SOME SHORT PERIODS OF COLD AIR ACROSS THE
MISSISSIPPI AND OHIO VALLEYS. ACROSS ALASKA, NEAR SHORE SSTS ARE MODERATING, SO
PROBABILITIES ARE LOW. TRENDS STILL FAVOR ABOVE-NORMAL TEMPERATURES ALONG THE
NORTHERN COAST. LA NINA RELATED FORCINGS WOULD FAVOR COOLER THAN AVERAGE
CONDITIONS ALONG SOUTHERN MAINLAND ALASKA AND THE ALASKA PANHANDLE, THOUGH
GUIDANCE EARLY IN THE MONTH SHOWS A LIKELY PERIOD OF SIGNIFICANT WARMTH THAT
WANES, SO PROBABILITIES ARE LOW ALONG THE SOUTHERN COAST FOR BELOW-NORMAL
TEMPERATURES.
THE PRECIPITATION OUTLOOK REFLECTS HIGH PROBABILITIES OF A WET START TO THE
MONTH FROM THE SOUTHERN GREAT PLAINS TO THE GREAT LAKES. FORECAST PRECIPITATION
TOTALS DURING THE FIRST WEEK OF THE MONTH WOULD RULE OUT BELOW OR EVEN
NEAR-NORMAL PRECIPITATION FOR A LARGE SWATH OF THE CENTRAL CONUS. THIS IS A
LARGE CHANGE FROM THE MID-MONTH OUTLOOK AND HIGHLY RELATED TO SHORT-TERM
VARIABILITY. SOME MODELS CONTINUE A WETTER PATTERN ACROSS THE GREAT PLAINS
THROUGH THE LATTER HALF OF THE MONTH, WITH A MODERATION ALONG THE GULF COAST. A
DRY START TO THE MONTH ALONG THE EAST COAST, COMBINED WITH LATER MONTH OUTLOOKS
OF NEAR TO BELOW-NORMAL PRECIPITATION IS ENOUGH TO FAVOR BELOW-NORMAL
PRECIPITATION FROM NORTH CAROLINA TO NEW ENGLAND. PROBABILITIES ARE LOW AND
UNCERTAINTY HIGH, AS THE MJO WOULD FAVOR TROUGHING ACROSS THE CENTRAL CONUS,
POTENTIALLY BRINGING MOISTURE NORTHWARD DURING THE MIDDLE OF NOVEMBER. EARLY
MONTH STORM ACTIVITY AND THE DEVELOPING LA NINA FAVOR ABOVE-NORMAL
PRECIPITATION ACROSS THE PACIFIC NORTHWEST AND SOUTHERN PORTIONS OF ALASKA,
INCLUDING THE ALASKA PANHANDLE.
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********** PREVIOUS DISCUSSION FROM THE MIDDLE OF OCTOBER ************
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THE NOVEMBER 2024 OUTLOOK CONSIDERED THE CURRENT AND PROJECTED STATE OF EL NIñO
SOUTHERN OSCILLATION (ENSO), THE MADDEN JULIAN OSCILLATION (MJO), TRENDS, AND
RECENT SEA SURFACE TEMPERATURES (SSTS). TOOLS CONSIDERED ARE THE SEA SURFACE
TEMPERATURE BASED CONSTRUCTED ANALOG (SST-CA), CANONICAL CORRELATION ANALYSIS
(CCA), OPTIMAL CLIMATE NORMALS (OCN), ENSO-OCN BLEND, AND THE DYNAMICAL MODELS
IN BOTH THE NORTH AMERICAN MULTI-MODEL ENSEMBLE (NMME) AND COPERNICUS CLIMATE
CHANGE SERVICES (C3S) SUITES. OF NOTE, SOIL MOISTURE WAS NOT CONSIDERED DUE TO
THE WANING INFLUENCE AT THIS TIME OF YEAR. FURTHER, PRECIPITATION MEASUREMENTS
OVER ONTARIO CANADA WERE DEEMED UNRELIABLE SO THEY WERE NOT CONSIDERED IN THE
ANALYSIS OF TOOLS FOR THE PRECIPITATION OUTLOOK.
THE TEMPERATURE OUTLOOK IS CLOSE TO THE CONSOLIDATION OF THE STATISTICAL TOOLS
AND NMME, THOUGH NOTABLY SHIFTED TOWARD A LESS CERTAIN OUTLOOK IN THE PACIFIC
NORTHWEST AND NORTHERN GREAT PLAINS. THE LIKELY PROGRESSION OF THE MJO AND
ASSOCIATED DOWNSTREAM IMPACTS, COMBINED WITH SOME ANALYSES SHOWING AN
OVER-AMPLIFIED TREND IN THE MANY OF THE DYNAMICAL MODELS, LEADS TO LESS
CERTAINTY IN THE PACIFIC NORTHWEST AND NORTHERN GREAT PLAINS. UNCERTAINTY ABOUT
THE TEMPERATURE OUTCOMES ALONG THE MID-ATLANTIC RESULTED IN LOWERED
PROBABILITIES THERE COMPARED TO THE FINAL CONSOLIDATION, AS THE TOOLS INDICATE
EITHER NEAR- OR ABOVE-NORMAL TEMPERATURES. THE ONLY TOOL INDICATING
BELOW-NORMAL TEMPERATURES IS A SOIL MOISTURE BASED CONSTRUCTED ANALOG, WHICH
WAS NOT CONSIDERED DUE TO THE TIME OF YEAR. RECENT SST CHANGES TOWARD WARMER
TEMPERATURES AND CLIMATOLOGICALLY LOW SEA ICE FAVOR ABOVE-NORMAL TEMPERATURES
ACROSS THE NORTH SLOPE AND NORTHWEST COAST OF ALASKA. SLIGHTLY ELEVATED ODDS
FOR BELOW-NORMAL TEMPERATURES FROM THE KENAI PENINSULA TO THE ALASKA PENINSULA
ARE CONSISTENT WITH LA NIñA THOUGH ONLY WEAKLY SUPPORTED IN THE DYNAMICAL
MODELS.
THE PRECIPITATION OUTLOOK REFLECTS THE CONSISTENT SIGNALS AMONG THE TOOLS AND
DYNAMICAL MODELS. FAVORING BELOW-NORMAL PRECIPITATION ALONG MOST OF THE
SOUTHERN TIER IS RELATED TO THE DEVELOPING LA NIñA, AS WELL AS INDICATED IN
MOST OF THE TOOLS AND DYNAMICAL MODELS. THE CFS INDICATES SOME WETNESS ACROSS
THE SOUTHERN PLAINS, SO PROBABILITIES THERE ARE LOWER THAN THE SOUTHWEST AND
THE LOWER MISSISSIPPI VALLEY. STATISTICAL TOOLS ALSO INDICATE ABOVE-NORMAL
PRECIPITATION IN KANSAS AND OKLAHOMA BUT THE DYNAMICAL MODELS DO NOT, AND
CALIBRATIONS RESULT IN VERY SMALL AND UNCERTAIN AREAS. ACROSS THE PACIFIC
NORTHWEST, THE FORECAST FOR ABOVE-NORMAL PRECIPITATION IS SUPPORTED IN THE
DYNAMICAL MODELS (NMME AND C3S) AND ALIGNS WITH THE EMERGING LA NIñA.
ABOVE-NORMAL PRECIPITATION ACROSS NORTHERN ALASKA IS TYPICALLY ASSOCIATED WITH
WARMER SSTS AND LOWER SEA ICE. ALMOST ALL OF THE MODELS IN THE NMME SUITE HAVE
A SIGNAL FOR ABOVE-NORMAL PRECIPITATION ACROSS THE NORTH SLOPE, WHICH IS
RETAINED IN THE CALIBRATED OUTLOOKS.
FORECASTER: MATTHEW ROSENCRANS
THE CLIMATIC NORMALS ARE BASED ON CONDITIONS BETWEEN 1991 AND 2020, FOLLOWING
THE WORLD METEOROLOGICAL ORGANIZATION CONVENTION OF USING THE MOST RECENT 3
COMPLETE DECADES AS THE CLIMATE REFERENCE PERIOD. THE PROBABILITY ANOMALIES
FOR TEMPERATURE AND PRECIPITATION BASED ON THESE NEW NORMALS BETTER REPRESENT
SHORTER TERM CLIMATIC ANOMALIES THAN THE FORECASTS BASED ON OLDER NORMALS.
THE NEXT MONTHLY OUTLOOK...FOR DEC ... WILL BE ISSUED ON THU NOV 21 2024
THESE OUTLOOKS ARE BASED ON DEPARTURES FROM THE 1991-2020 BASE PERIOD.
CLICK HERE TO GO TO PREVIOUS BULLETINS.
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