Prognostic Meteorological Discussion
Issued by NWS

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6
000
FXUS21 KWNC 271815
PMDTHR
US HAZARDS OUTLOOK
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
300 PM EDT MAY 27 2015

SYNOPSIS: AT THE START OF THE PERIOD, A FRONTAL SYSTEM IS EXPECTED TO EXTEND
SOUTHWESTWARD FROM THE GREAT LAKES ACROSS THE MIDDLE MISSISSIPPI VALLEY TO THE
SOUTHERN PLAINS. THE FRONT IS FORECAST TO MOVE SLOWLY SOUTHEASTWARD BEFORE
STALLING AND THEN MOVING BACK NORTHEASTWARD AS A WARM FRONT. SURFACE LOW
PRESSURE OVER THE NORTHERN ROCKIES ON MAY 30 IS ANTICIPATED TO MOVE SLOWLY
EASTWARD TO THE NORTHERN PLAINS BY JUN 2. SURFACE LOW PRESSURE EXPECTED OVER
SOUTHEASTERN ALASKA ON MAY 30 IS EXPECTED TO MOVE VERY LITTLE THROUGH JUN 2. AN
AREA OF DISTURBED WEATHER SOUTH OF THE MEXICAN COAST IS FORECAST TO TRACK
TOWARDS THE WEST-NORTHWEST.



HAZARDS

HEAVY RAIN FOR PARTS OF THE MIDDLE MISSISSIPPI AND OHIO VALLEYS, GREAT LAKES,
CENTRAL APPALACHIANS, MID-ATLANTIC, AND NORTHEAST, SAT-SUN, MAY 30-31.

HEAVY RAIN FOR PARTS OF THE NORTHERN ROCKIES AND NORTHERN PLAINS, MON-TUE, JUN
1-2.

ENHANCED WILDFIRE RISK FOR INTERIOR EASTERN ALASKA, SAT-WED, MAY 30-JUN 3.

FLOODING IS POSSIBLE, IMMINENT, OR OCCURRING ACROSS PORTIONS OF THE CENTRAL AND
WEST-CENTRAL CONUS.

SEVERE DROUGHT FOR PARTS OF THE NORTHERN, CENTRAL, AND SOUTHERN GREAT PLAINS,
SOUTHWEST, GREAT BASIN, CALIFORNIA, AND THE PACIFIC NORTHWEST.

DETAILED SUMMARY

FOR SATURDAY MAY 30 - WEDNESDAY JUNE 03: AN UPPER-LEVEL RIDGE IS EXPECTED TO
LEAD TO VERY WARM DAILY MAXIMUM TEMPERATURES (POSITIVE ANOMALIES OF 10-15
DEGREES F) FOR PARTS OF THE NORTHWESTERN CONUS MAY 30-31. WHILE SOME LOCATIONS
MAY APPROACH 90 DEGREES F, A HAZARD SHAPE IS NOT DEEMED WARRANTED.



AT THE START OF THE PERIOD A FRONTAL SYSTEM IS FORECAST TO STRETCH
SOUTHWESTWARD FROM THE GREAT LAKES ACROSS THE MIDDLE MISSISSIPPI VALLEY TO THE
SOUTHERN PLAINS. AS THE FRONT MOVES SLOWLY SOUTHEASTWARD IT IS EXPECTED TO ACT
AS A FOCUSING MECHANISM FOR SHOWERS AND THUNDERSTORMS. HEAVY RAIN (IN EXCESS OF
1 INCH IN 24 HOURS) IS EXPECTED FOR PARTS OF THE MIDDLE MISSISSIPPI AND OHIO
VALLEYS, GREAT LAKES, CENTRAL APPALACHIANS, MID-ATLANTIC, AND NORTHEAST MAY
30-31. THUNDERSTORMS ARE LIKLEY DURING THE PERIOD OVER THESE REGIONS BUT MODEL
UNCERTAINTY PRECLUDES THE SPECIFICATION OF A SEVERE WEATHER HAZARD AT THE
CURRENT TIME.



LOW PRESSURE MOVING ACROSS THE NORTHERN ROCKIES LEADS TO HEAVY RAIN (IN EXCESS
OF 1 INCH IN 24 HOURS) FOR PARTS OF THE REGION JUNE 1-2.



IN THE EASTERN INTERIOR OF ALASKA, CONTINUED WARM, DRY, AND BREEZY CONDITIONS
FAVOR A SIGNIFICANTLY INCREASED CHANCE OF CRITICAL WILDFIRE CONDITIONS
THROUGHOUT THIS PERIOD.



NUMEROUS AREAS OF POSSIBLE, LIKELY, IMMINENT, AND OCCURRING FLOODING ARE
INDICATED OVER THE CENTRAL AND WEST-CENTRAL PORTIONS OF THE CONUS, WITH ALL THE
HEAVY RAIN RECEIVED IN RECENT DAYS AND WEEKS. TO OBTAIN THE VERY LATEST,
DETAILED INFORMATION ON THE STATUS OF STREAMS AND RIVERS ACROSS THE U.S.,
PLEASE CONSULT THE RIVER FORECAST CENTER (RFC) HOMEPAGE AT:
HTTP://WATER.WEATHER.GOV/AHPS/RFC/RFC.PHP.

FOR THURSDAY JUNE 04 - WEDNESDAY JUNE 10: THE EXPECTED MID-TROPOSPHERIC FLOW
PATTERN FOR WEEK-2 FEATURES BASICALLY ZONAL FLOW ACROSS THE NORTHERN HALF OF
THE CONUS. SIGNIFICANT POSITIVE HEIGHT ANOMALIES AT 500-HPA (RANGING FROM +60
TO +100 METERS) ARE FORECAST ACROSS THE NORTHEAST, AND ARE EXPECTED TO COINCIDE
WITH ABOVE NORMAL SURFACE TEMPERATURES DURING THIS PERIOD FOR THAT REGION.



THE MOST RECENT U.S. DROUGHT MONITOR, RELEASED MAY 21ST, INDICATES A
SUBSTANTIAL DECREASE (FROM 17.68 TO 15.16) IN THE PERCENTAGE OF THE CONUS IN
SEVERE TO EXCEPTIONAL DROUGHT (D2-D4).

FORECASTER: RANDY SCHECHTER

$$




USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.