Prognostic Meteorological Discussion
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FXUS21 KWNC 041842
PMDTHR
US HAZARDS OUTLOOK
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
300 PM EDT AUGUST 04 2015

SYNOPSIS: A LOW PRESSURE CENTER IS FORECAST TO MOVE FROM NORTH CAROLINA
NORTHEASTWARD TO THE GULF OF MAINE DURING THE FIRST FEW DAYS OF THE OUTLOOK
PERIOD, WITH ITS ASSOCIATED COLD FRONT EXPECTED TO PUSH INTO THE DEEP SOUTH.
ANOTHER FRONTAL SYSTEM IS ANTICIPATED TO MOVE EASTWARD ACROSS THE NORTHERN
CONUS DURING THE SAME TIME PERIOD, WEAKENING AS IT APPROACHES NEW ENGLAND.
THESE TWO SYSTEMS ARE PREDICTED TO BE THE MAIN PRODUCERS OF PRECIPITATION
DURING THE 3-7 DAY PERIOD ACROSS THE CONTIGUOUS U.S. TROPICAL STORM GUILLERMO,
CURRENTLY LOCATED OVER THE EAST-CENTRAL TROPICAL PACIFIC OCEAN, IS FORECAST TO
PASS NORTH OF THE HAWAIIAN ISLANDS PRIOR TO THE BEGINNING OF THIS OUTLOOK. A
FAIRLY LARGE LOW PRESSURE SYSTEM IS ANTICIPATED TO AFFECT SOUTHWESTERN AND
SOUTHERN ALASKA.

HAZARDS

HEAVY RAIN FROM VIRGINIA NORTHEASTWARD TO MASSACHUSETTS, FRI-SAT, AUG 7-8.

EXCESSIVE HEAT FOR THE EASTERN HALF OF THE SOUTHERN PLAINS, AND THE LOWER
MISSISSIPPI VALLEY, FRI-TUE, AUG 7-11.

FLOODING IS POSSIBLE FROM NORTHEAST MISSOURI TO NORTH-CENTRAL ILLINOIS,
FRI-SUN, AUG 7-9.

FLOODING IS PROBABLE IN NORTH-CENTRAL MISSOURI, FRI-SUN, AUG 7-9.

SEVERE DROUGHT FOR PARTS OF THE WESTERN THIRD OF THE CONUS, SOUTHERN GEORGIA,
SOUTHERN FLORIDA, NORTH CAROLINA AND HAWAII.

SLIGHT CHANCE OF MUCH ABOVE-NORMAL TEMPERATURES ACROSS THE EASTERN HALF OF THE
SOUTHERN PLAINS, THE LOWER MISSISSIPPI VALLEY, AND PORTIONS OF ALABAMA AND THE
FLORIDA PANHANDLE, WED-FRI, AUG 12-14.

DETAILED SUMMARY

FOR FRIDAY AUGUST 07 - TUESDAY AUGUST 11: A LOW PRESSURE CENTER MOVING
NORTHEASTWARD FROM NORTH CAROLINA TO THE GULF OF MAINE IS PREDICTED TO BRING
HEAVY RAIN (UP TO 2 INCHES) TO THE I-95 CORRIDOR BETWEEN WASHINGTON, D.C., AND
BOSTON, ON FRIDAY AND SATURDAY. THE ASSOCIATED COLD FRONT IS FORECAST TO PUSH
INTO THE DEEP SOUTH, BEFORE STALLING. THE FLORIDA PANHANDLE MAY RECEIVE AN INCH
OF RAIN DURING THE SAME TWO-DAY PERIOD, BUT THIS AMOUNT DOES NOT EXCEED
HAZARDOUS CRITERIA.



AN AREA OF EXCESSIVE HEAT IS DESIGNATED ACROSS THE EASTERN HALF OF THE SOUTHERN
PLAINS, AND THE LOWER MISSISSIPPI VALLEY DURING THIS PERIOD. DAILY MAXIMUM HEAT
INDICES ARE FORECAST TO RANGE BETWEEN 105-110 DEGREES F. THE PLACES MOST LIKELY
TO EXPERIENCE THESE CONDITIONS FOR THIS ENTIRE 5-DAY PERIOD ARE NEAR THE GULF
COAST.



AREAS OF POSSIBLE/PROBABLE FLOODING ARE INDICATED OVER THE MIDWEST FROM FRIDAY
THROUGH SUNDAY. THESE ARE DUE TO BOTH ANTECEDENT RAINFALL DURING THE PAST WEEK,
AND PREDICTED RAINFALL FOR THE UPCOMING WEEK.



ACCORDING TO THE USDA FOREST SERVICE, THERE ARE ABOUT 2 DOZEN LARGE WILDFIRES
IN PROGRESS ACROSS THE WEST COAST STATES, WITH THE GREATEST CONCENTRATION OF
WILDFIRES IN CALIFORNIA. MOST OF THE FIRES IN NORTHERN AND CENTRAL CALIFORNIA
HAVE BURNED LESS THAN 14,000 ACRES. HOWEVER, THERE IS A PROMINENT EXCEPTION.
JUST NORTH OF SAN FRANCISCO (LAKE COUNTY), THERE IS A WILDFIRE THAT HAS ALREADY
BURNED 62,000 ACRES, WHICH IS A 15 PERCENT INCREASE FROM YESTERDAY. THIS
WILDFIRE IS ONLY 12 PERCENT CONTAINED AT THIS TIME. MANY OF THE WILDFIRES NEAR
THE WEST COAST APPEAR TO BE RELATED TO STRONGER WINDS ASSOCIATED WITH A 500-HPA
TROUGH NEAR THE COAST, AND THE PRESENCE OF DRY VEGETATIVE FUELS IN THIS REGION.



AS OF 5AM HAWAIIAN TIME, TROPICAL STORM GUILLERMO WAS LOCATED ABOUT 430 MILES
EAST OF HILO, HI, MOVING TOWARD THE HAWAIIAN ARCHIPELAGO. IT IS STILL A STRONG
TROPICAL STORM, WITH MAXIMUM SUSTAINED WINDS OF 70 MPH. THE OFFICIAL TRACK,
ISSUED BY THE CENTRAL PACIFIC HURRICANE CENTER (CPHC) IN HONOLULU, HAS
GUILLERMO PASSING NORTH OF HAWAII AS A STILL-POTENT TROPICAL STORM BEFORE THE
START OF THIS PERIOD. EVEN THOUGH IT APPEARS THAT THE ISLANDS WILL BE SPARED
THE WORST OF GUILLERMO, RESIDENTS ARE ENCOURAGED TO KEEP UPDATED ON THE FUTURE
PROGRESS OF THIS STORM BY CONSULTING LOCAL NEWS MEDIA, AND/OR THE CPHC AT:
HTTP://WWW.PRH.NOAA.GOV/HNL/CPHC/ UNTIL THE HAZARD PASSES. IN THE ATLANTIC
BASIN, A LOW PRESSURE AREA WITH INCREASING THUNDERSTORM ACTIVITY AND 35 MPH
WINDS (EAST AND SOUTH OF THE CENTER, OVER WATER) IS CURRENTLY LOCATED NEAR
MYRTLE BEACH, SC. EVEN IF THIS SYSTEM DEVELOPS FURTHER, IT IS EXPECTED TO MOVE
AWAY FROM THE EAST COAST TONIGHT AND TOMORROW. PLEASE REFER TO THE NATIONAL
WEATHER SERVICE AND LOCAL NEWS MEDIA FOR UPDATES ON THIS SYSTEM.



A FAIRLY LARGE LOW PRESSURE SYSTEM IS PREDICTED TO MOVE EASTWARD ACROSS THE
SOUTHERN COAST OF ALASKA DURING THIS PERIOD, BRINGING CLOUDS AND PRECIPITATION.
HOWEVER, AT THIS TIME, NO WEATHER-RELATED HAZARDS ARE EXPECTED WITH THIS SYSTEM.

FOR WEDNESDAY AUGUST 12 - TUESDAY AUGUST 18: BY THE END OF THE 3-7 DAY PERIOD,
AND INTO AT LEAST THE FIRST HALF OF WEEK-2, THE HIGHEST 500-HPA HEIGHTS
ASSOCIATED WITH THE SUBTROPICAL RIDGE ARE FORECAST TO BE LOCATED OVER THE
SOUTHERN GREAT PLAINS REGION. THIS FAVORS A SLIGHT RISK OF MUCH ABOVE-NORMAL
TEMPERATURES ACROSS THE SOUTH-CENTRAL CONUS. MID-TROPOSPHERIC TROUGHS ARE
ANTICIPATED NEAR THE PACIFIC COAST, AND THE ATLANTIC COAST STATES.



THE LATEST WEEKLY U.S. DROUGHT MONITOR MAP, RELEASED ON JULY 30TH, SHOWS A
SLIGHT INCREASE IN THE COVERAGE OF SEVERE TO EXCEPTIONAL DROUGHT (D2 TO D4)
ACROSS THE CONTIGUOUS U.S., FROM 16.74 PERCENT TO 17.17 PERCENT. ACCORDING TO
AHPS, RAINFALL HAS BEEN BELOW-NORMAL DURING THE PAST TWO WEEKS FOR MOST AREAS
EAST OF THE MISSISSIPPI RIVER, THOUGH WITH ONE SIGNIFICANT EXCEPTION. FOR MOST
OF THE NORTHWEST QUARTER OF THE FLORIDA PENINSULA, RAINFALL AMOUNTS HAVE RANGED
FROM 5-8 INCHES ABOVE NORMAL, AND EVEN HIGHER IN SOME LOCALIZED AREAS. THIS IS
ASSOCIATED WITH A WEAK AREA OF LOW PRESSURE OVER NORTHERN FLORIDA. IN CONTRAST,
SOUTHERN FLORIDA IS RUNNING A 1-3 INCH RAINFALL DEFICIT DURING THE LAST 14 DAYS.

FORECASTER: ANTHONY ARTUSA

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