247
FXUS21 KWNC 241839
PMDTHR
US HAZARDS OUTLOOK
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
300 PM EDT JULY 24 2024
SYNOPSIS: COAST-TO-COAST MID-LEVEL HIGH PRESSURE IS PREDICTED ACROSS THE
CONTIGUOUS U.S. (CONUS) DURING WEEK-2. THIS IS ASSOCIATED WITH FAVORED
WARMER-THAN-NORMAL TEMPERATURES FOR MOST OF THE LOWER 48 STATES. EXCESSIVE HEAT
IS MOST LIKELY ACROSS THE WEST-CENTRAL, CENTRAL, AND NORTHEASTERN CONUS DURING
THE WEEK-2 OUTLOOK PERIOD. IN ALASKA, MID-LEVEL LOW PRESSURE IS FORECASTED
ACROSS MOST OF THE STATE, WITH THE EXCEPTION OF THE ALEUTIAN ARCHIPELAGO WHERE
MID-LEVEL HIGH PRESSURE IS FAVORED.
HAZARDS
HIGH RISK OF EXCESSIVE HEAT FOR THE SOUTH-CENTRAL PLAINS AND NORTHERN AND
WESTERN MISSOURI, THU-MON, AUG 1-5.
MODERATE RISK OF EXCESSIVE HEAT FOR THE NORTHEAST AND MID-ATLANTIC REGION,
THU-WED, AUG 1-7.
MODERATE RISK OF EXCESSIVE HEAT FOR PORTIONS OF THE INTERIOR WEST, ALL BUT FAR
SOUTHERN PORTIONS OF THE GREAT PLAINS, AND CENTRAL PORTIONS OF THE MISSISSIPPI
VALLEY, THU-WED, AUG 1-7.
SLIGHT RISK OF EXCESSIVE HEAT FOR THE INTERIOR WEST, MOST OF THE GREAT PLAINS,
MOST OF THE MISSISSIPPI AND OHIO VALLEYS, THE GREAT LAKES REGION, NORTHEAST,
AND MID-ATLANTIC, THU-WED, AUG 1-7.
SLIGHT RISK OF EXCESSIVE HEAT FOR THE CENTRAL VALLEY OF CALIFORNIA, FRI-WED,
AUG 2-7.
RAPID ONSET DROUGHT RISK FOR PORTIONS OF THE NORTHERN AND CENTRAL PLAINS.
DETAILED SUMMARY
FOR SATURDAY JULY 27 - WEDNESDAY JULY 31:
HTTPS://WWW.WPC.NCEP.NOAA.GOV/THREATS/THREATS.PHP
FOR THURSDAY AUGUST 01 - WEDNESDAY AUGUST 07: FOR THE WEEK-2 PERIOD, ENSEMBLE
MEANS FAVOR ANOMALOUS MID-LEVEL RIDGING AND ACCOMPANYING POSITIVE HEIGHT
DEPARTURES ACROSS THE CONUS, WITH MAXIMUM 500-HPA HEIGHTS OF AT LEAST 594 DM
ACROSS THE SOUTHWESTERN AND SOUTH-CENTRAL STATES.
THE WEEK-2 TEMPERATURE OUTLOOK FAVORS ABOVE-NORMAL TEMPERATURES OVER ALMOST ALL
OF THE CONUS. A SLIGHT RISK OF EXCESSIVE HEAT IS DEPICTED ACROSS MOST OF THE
LOWER 48 STATES OUTSIDE OF THE SOUTHEAST AND SOUTHERN TEXAS, AND VALID FOR THE
ENTIRE OUTLOOK PERIOD. WITHIN THIS EXTENSIVE SLIGHT RISK AREA, THERE ARE TWO
AREAS WHERE A MODERATE RISK OF EXCESSIVE HEAT IS FAVORED. ONE AREA INCLUDES THE
NORTHEAST AND MUCH OF THE MID-ATLANTIC REGION, VALID AUG 1-7. THE SECOND,
LARGER AREA INCLUDES MUCH OF THE INTERIOR WEST, MOST OF THE GREAT PLAINS, AND
CENTRAL SECTIONS OF THE MISSISSIPPI VALLEY, AUG 1-7. WITHIN THIS SECOND, LARGER
AREA, THERE IS A HIGH RISK OF EXCESSIVE HEAT FOR THE SOUTH-CENTRAL PLAINS AND
ADJACENT PARTS OF THE MISSISSIPPI VALLEY, VALID AUG 1-5. A GENERAL CONSENSUS OF
TEMPERATURE AND EXCESSIVE HEAT GUIDANCE INDICATES ACTUAL AIR TEMPERATURES
ACROSS PORTIONS OF THE NORTHEAST AND MID-ATLANTIC REGION MAY REACH WELL INTO
THE 90’S, WITH HEAT INDEX VALUES EXCEEDING 100 DEG F. FOR THE PLAINS, MAXIMUM
AIR TEMPERATURES OF 100-105 DEG F ARE EXPECTED, WITH HEAT INDEX VALUES
SURPASSING 110 DEG F OVER PORTIONS OF THE SOUTH-CENTRAL PLAINS. A SKILL
WEIGHTED, BIAS-CORRECTED HYBRID TOOL (WHICH CONSIDERS ACTUAL AIR TEMPERATURE
AND HEAT INDEX), RAW TEMPERATURES FROM THE ENSEMBLE MEANS, AND PROBABILISTIC
EXTREMES TOOL (PET) TEMPERATURES WERE USED IN THE CONSTRUCTION OF TODAY’S
EXCESSIVE HEAT MAP. BASED ON THESE SAME OBJECTIVE TOOLS, A SLIGHT RISK OF
EXCESSIVE HEAT IS DEPICTED FOR THE CENTRAL VALLEY OF CALIFORNIA, AUG 2-7, WHERE
HEAT INDEX VALUES MAY APPROACH OR EXCEED 110 DEG F.
THE SUBTROPICAL RIDGE IS PREDICTED TO BE CENTERED OVER THE FOUR CORNERS REGION
DURING WEEK-2, IN ITS CLIMATOLOGICAL POSITION DURING THE SUMMER MONSOON SEASON.
THE 06Z AND 12Z GEFS RUNS ARE PREDICTING A TROPICAL CYCLONE OVER THE EASTERN
PACIFIC TO PASS SOUTH OF THE GULF OF CALIFORNIA EARLY IN THE OUTLOOK PERIOD.
THIS SCENARIO MAY TRIGGER A GULF SURGE OF MOISTURE INTO THE AMERICAN SOUTHWEST,
WITH THE PET PRECIPITATION TOOL DEPICTING AMOUNTS OF ABOUT 0.5-INCH. HOWEVER,
NO PRECIPITATION HAZARD IS PREDICTED AT THIS TIME.
THE HEAVIEST PRECIPITATION AMOUNTS PREDICTED DURING THIS OUTLOOK PERIOD RANGE
FROM 1.0-1.5 INCHES OVER A 3-DAY PERIOD, FOCUSED ALONG THE SOUTHEAST AND GULF
COASTS. HOWEVER, NORMAL WEEKLY PRECIPITATION AMOUNTS FOR THOSE AREAS RANGE FROM
1.0-1.5 INCHES IN MOST AREAS TO ALMOST 2 INCHES ALONG THE GULF COAST OF
FLORIDA. THEREFORE, NO PRECIPITATION HAZARDS ARE DEPICTED ON TODAY’S HAZARDS
MAP. HOWEVER, ACCORDING TO THE EXPERIMENTAL FLOOD HAZARD OUTLOOK, THIS AMOUNT
OF PRECIPITATION IS ENOUGH TO RENEW FLOODING CHANCES ACROSS THE EASTERN COASTAL
REGION OF NORTH CAROLINA, WHICH RECENTLY EXPERIENCED HEAVY PRECIPITATION AND
HAS ELEVATED SOIL MOISTURE ANOMALIES.
THE COMBINATION OF CONTINUED ABOVE-NORMAL TEMPERATURES AND BELOW-NORMAL
PRECIPITATION SUPPORTS THE CONTINUATION OF A RAPID ONSET DROUGHT (ROD) RISK
OVER MANY PARTS OF THE NORTHERN AND CENTRAL HIGH PLAINS. DRY SOILS, STRESSED
VEGETATION, AND REDUCED WATER AVAILABILITY DUE TO LOW PONDS AND STREAMS MAY
LEAD TO INCREASED IMPACTS TO AGRICULTURE AND LIVESTOCK, WITH SOME LOCATIONS
ALREADY EXPERIENCING IMPACTS.
NO HAZARDS ARE POSTED FOR ALASKA DURING WEEK-2. HOWEVER, THERE IS A SIGNIFICANT
CHANCE OF ACCUMULATING SNOW FOR PORTIONS OF THE CENTRAL AND EASTERN BROOKS
RANGE, WHICH COULD HAVE AN IMPACT ON PEOPLE WITHIN THAT AREA. THIS POSSIBILITY
WILL BE REASSESSED TOMORROW AFTER LOOKING AT THE MOST RECENT MODEL SOLUTIONS.
NEAR JUNEAU, LOCALIZED FLOODING MAY BE A CONCERN ASSOCIATED WITH THE GLACIAL
OUTBURST FLOOD FOR THE MENDENHALL RIVER.
FORECASTER: ANTHONY ARTUSA
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