693
FXUS07 KWBC 151230
PMD30D
PROGNOSTIC DISCUSSION FOR MONTHLY OUTLOOK
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
830 AM EDT THU MAY 15 2025
30-DAY OUTLOOK DISCUSSION FOR JUNE 2025
THE JUNE 2025 TEMPERATURE AND PRECIPITATION OUTLOOKS ARE BASED ON THE: NORTH
AMERICAN MULTI-MODEL ENSEMBLE (NMME) AND INTERNATIONAL MULTI-MODEL ENSEMBLE
(IMME), CONSOLIDATION (STATISTICAL AND DYNAMICAL TOOLS), SOIL MOISTURE
INFLUENCE AND ITS CONSTRUCTED ANALOG, AND DECADAL TRENDS. THE MADDEN-JULIAN
OSCILLATION (MJO) REMAINS WEAK AND DYNAMICAL MODEL SPREAD IS HIGH ON WHETHER
THE MJO MAY STRENGTHEN HEADING INTO JUNE. ALTHOUGH THE MJO IS UNLIKELY TO
AFFECT THE MID-LATITUDE CIRCULATION PATTERN DURING JUNE, IT WILL BE CLOSELY
MONITORED AS IT COULD CONTRIBUTE TO A MORE FAVORABLE ENVIRONMENT FOR AN EARLY
SEASON TROPICAL CYCLONE IN THE ATLANTIC BASIN. ENSO-NEUTRAL CONDITIONS ARE
FORECAST TO CONTINUE THROUGHOUT JUNE.
THE HIGHEST FORECAST CONFIDENCE IN THE TEMPERATURE OUTLOOK IS FOR ABOVE-NORMAL
TEMPERATURES (PROBABILITIES GREATER THAN 60 PERCENT) ACROSS THE SOUTHWEST,
BASED ON THE CALIBRATED NMME, WARMING INFLUENCE FROM LOW SOIL MOISTURE, AND
CONSISTENT WITH DECADAL TRENDS. THE JUNE OUTLOOK REFLECTS THE NMME AND IMME
WITH THEIR DECREASING ABOVE-NORMAL TEMPERATURE PROBABILITIES FARTHER TO THE
NORTH OVER THE WEST. PROBABILITIES ARE ALSO LOWER ACROSS MUCH OF OKLAHOMA AND
NORTHEASTERN TEXAS WHERE HIGH SOIL MOISTURE (ABOVE THE 90TH PERCENTILE) WOULD
HAVE A COOLING EFFECT ON SURFACE TEMPERATURES IN THE COMING WEEKS. IN ADDITION,
A CONSTRUCTED ANALOG DERIVED FROM SOIL MOISTURE DEPICTS A WEAK COLD SIGNAL. THE
NMME AND THE DECADAL TREND SUPPORT AN INCREASED CHANCE OF ABOVE-NORMAL
TEMPERATURES FOR MOST OF THE EAST WITH THE LARGEST PROBABILITIES (EXCEEDING 50
PERCENT) FORECAST ACROSS THE FLORIDA PENINSULA. DUE TO LITTLE OR NO SIGNAL IN
THE NMME AND A MORE NEUTRAL TREND, EQUAL CHANCES (EC) OF BELOW, NEAR, OR
ABOVE-NORMAL TEMPERATURES ARE FORECAST FOR PARTS OF THE NORTHEAST AND GREAT
LAKES. CONSISTENT WITH THE NMME AND DECADAL TRENDS, ABOVE-NORMAL TEMPERATURES
ARE MORE LIKELY ACROSS THE SOUTHERN TIER OF ALASKA WITH EC FORECAST FOR THE
NORTHERN TWO-THIRDS OF MAINLAND ALASKA.
BASED ON THE NMME, IMME, CONSTRUCTED ANALOG FROM SOIL MOISTURE, AND TREND,
BELOW-NORMAL PRECIPITATION IS FAVORED FOR PARTS OF THE PACIFIC NORTHWEST,
NORTHERN INTERMOUNTAIN WEST, GREAT BASIN, ROCKIES, AND HIGH PLAINS. THE LARGEST
BELOW-NORMAL PRECIPITATION PROBABILITIES (GREATER THAN 40 PERCENT) EXTEND FROM
IDAHO AND SOUTHWESTERN MONTANA SOUTHEASTWARD TO THE SOUTHERN HIGH PLAINS WHERE
THE DYNAMICAL MODEL OUTPUT AND STATISTICAL TOOLS ARE IN THE BEST AGREEMENT. IN
THE CLIMATOLOGICALLY DRIER AREAS OF CALIFORNIA AND THE SOUTHWEST, EC IS
FORECAST. THE CONSTRUCTED ANALOG USING SEA SURFACE TEMPERATURES DEPICTS A WET
SIGNAL FOR THE SOUTHWEST, IMPLYING AN EARLY, ROBUST START TO THE MONSOON. THIS
WOULD ALSO BE CONSISTENT WITH ONGOING LOW SOIL MOISTURE FOR THE SOUTHWEST.
HOWEVER, FORECAST CONFIDENCE WAS NOT HIGH ENOUGH AT THIS TIME TO LEAN TOWARDS
ABOVE-NORMAL PRECIPITATION, GIVEN THE LACK OF DYNAMICAL MODEL SUPPORT, BUT THIS
REGION WILL BE REEVALUATED FOR THE UPDATE RELEASED ON MAY 31ST. A BROAD AREA
WITH EC COVERS MUCH OF THE GREAT PLAINS AND MISSISSIPPI VALLEY DUE TO A WEAK
SIGNAL AMONG THE PRECIPITATION TOOLS ALONG WITH LARGE UNCERTAINTY IN PREDICTING
AREAS OF ANOMALOUS CONVECTIVE RAINFALL AT A HALF-MONTH LEAD. A SLIGHT LEAN
TOWARDS ABOVE-NORMAL PRECIPITATION IS FORECAST FOR THE EAST AND PARTS OF THE
GREAT LAKES WITH THE NMME, IMME, CONSTRUCTED ANALOG FROM SOIL MOISTURE, AND
TREND AT LEAST HAVING A WEAK SIGNAL FOR A WETTER-THAN-NORMAL JUNE. FOR ALASKA,
ABOVE-NORMAL PRECIPITATION IS MOST LIKELY ACROSS SOUTHEASTERN PARTS OF THE
STATE WHICH IS SUPPORTED BY THE NMME AND TREND.
FORECASTER: BRAD PUGH
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.
AN UPDATED MONTHLY OUTLOOK... FOR JUN WILL BE ISSUED ON SAT MAY 31 2025
THESE OUTLOOKS ARE BASED ON DEPARTURES FROM THE 1991-2020 BASE PERIOD.
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