Severe Thunderstorm Warning 40, NWS Raleigh, NC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
253 PM EDT FRI MAY 28 2010

.SYNOPSIS...
A COLD FRONT WILL DRIFT SOUTHWESTWARD INTO THE REGION TODAY THROUGH
SATURDAY...INCREASING THE CHANCE OF THUNDERSTORMS. MORE STABLE
CONDITIONS ARE ANTICIPATED FOR SUNDAY AND MONDAY AS HIGH PRESSURE
BUILDS ALOFT OVER THE AREA.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 240 PM FRIDAY...

MID TO LATE AFTERNOON CONVECTION STILL EXPECTED TO DEVELOP. CUMULUS
FIELDS BECOMING EXTENSIVE IN THE FOOTHILLS AND BEGINNING TO FORM IN
THE WESTERN AND NORTHERN PIEDMONT. AIR MASS TYPICAL OF A DRIER
SUMMER DAY WITH WEAK WINDS BUT DECENT SURFACE INSTABILITY.
THUNDERSTORMS SHOULD BE PULSE IN NATURE AND ISOLATED DAMAGING WINDS
POSSIBLE. NO DECENT SURFACE BOUNDARIES PRESENT BUT THETA-E GRADIENT
BEST IN OUR WEST AND SOUTH PARTS. UPPER LEVEL SHORT WAVE IN THE
MIDWEST DIVING SOUTH SOUTHWEST AND ITS JET LEVEL DIVERGENCE FIELD
LOOKS TO REMAIN WEST OF OUR AREA.

SOME FOG LATE TONIGHT BUT NOT EXPECTED TO BE SIGNIFICANT ENOUGH TO
MENTION IN THE TEXT PRODUCTS. SOME STRATUS LATE TONIGHT. LOW LEVEL
MOISTURE LOOKS BEST TOWARD VIRGINIA AND INTO THE NORTHWEST
PIEDMONT... AND THESE AREAS FAVORED... THOUGH BRIEF SUNRISE LOW
OVERCAST POSSIBLE ALMOST ANYWHERE. OVERNIGHT LOW TEMPERATURES WILL
AGAIN BE MILD WITH MID TO UPPER 60S FORECAST.

&&

.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
AS OF 240 PM FRIDAY...

MID LEVEL WINDS BECOME SOLIDLY SOUTHWEST SATURDAY AND MINIMALLY
CONVERGENT ACROSS NORTH PARTS DURING THE AFTERNOON. MODELS ARE TOO
MOIST WITH THEIR SURFACE DEW POINTS... OVERDOING SURFACE INSTABILITY
PARAMETERS. WARMING ABOVE 700 MILLIBARS FORECAST... WHICH WILL
LESSEN THE STRENGTH OF ANY UPDRAFTS IN THE MID LEVELS. FORTY PERCENT
RAIN CHANCE NORTH AND THIRTY PERCENT SOUTH. AFTERNOON HIGH
TEMPERATURES 80 TO 84.

SATURDAY NIGHT WILL SEE CONVECTION DIMINISH WITH THE LOSS OF
AFTERNOON HEATING. LIGHT SOUTHWEST FLOW OVERNIGHT WITH LOW
TEMPERATURES 65 TO 69.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
AS OF 250 PM FRIDAY...

A RETROGRESSING CUTOFF LOW WILL BE PINNED OVER THE GULF STATES
SUNDAY AND MONDAY IN A LINGERING REX BLOCKING PATTERN.
MEANWHILE...WE WILL BE STAGNANT AND COOKING UNDER A GRADUALLY
WEAKENING RIDGE AXIS OVERHEAD. FORCING WILL BE VERY LIMITED AND
AM ONLY LOOKING FOR ISOLATED DIURNAL CONVECTION SUNDAY AND MONDAY
WITH HIGHS REACHING AROUND 90 AFTER MORNING LOWS IN THE 65 TO 70
RANGE.

THE BLOCKING PATTERN BEGINS TO BREAK DOWN AND DEAMPLIFY AND THE
UPPER CUTOFF LOW WILL WEAKEN AND BEGIN TO BE ABSORBED INTO THE
BROADER WESTERLY FLOW OVER THE CONUS. REMNANTS OF THIS LOW WILL BE
PICKED UP ON THE SOUTHERN END OF AN APPROACHING FRONT MONDAY NIGHT
AND TUESDAY. AS SUCH...POPS WILL INCREASE TO CHANCE TUESDAY AND
WEDNESDAY WITH A SLIGHT REDUCTION IN HIGH TEMPS...85-90.

LOTS OF UNCERTAINTY IN THE LATER EXTENDED...BUT WARM TEMPS...UPPER
80S...AND ABUNDANT MOISTURE WILL BE IN PLACE. WORTH AT LEAST A
CLIMATOLOGICAL CHANCE FOR AFTERNOON/EVENING CONVECTION.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 215 PM...

CUMULUS BEGINNING TO DEVELOP OVER THE AREA WITH CONVECTION
EXPECTED MID TO LATE AFTERNOON. LITTLE TO KEEP THUNDERSTORMS GOING
OVERNIGHT EXCEPT THE INSTABILITY OF THE AIR MASS... BUT SOME
STORMS MAY PERSIST TO MIDNIGHT.

AREAS OF IFR CEILINGS AND MVFR FOG BEFORE DAWN INTO SUNRISE
SATURDAY MORNING. SCATTERED SHOWERS WITH A FEW THUNDERSTORMS...
MAINLY AFTERNOON. THE STORMS WILL NOT BE AS VIGOROUS AS THOSE
EXPECTED TODAY.

FOR SATURDAY NIGHT THROUGH WEDNESDAY....EXPECT PROLONG PERIODS OF
VFR CONDITIONS WITH A FEW HOURS OF MVFR CEILINGS AND VISIBILITY
BETWEEN 09Z-13Z EACH MORNING. AFTERNOON SHOWERS AND
THUNDERSTORMS... A BIT MORE WIDESPREAD TUESDAY AND WEDNESDAY.

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

SYNOPSIS...RE
NEAR TERM...RLH
SHORT TERM...RLH
LONG TERM...MLM
AVIATION...RLH

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE RALEIGH NC
416 AM EDT FRI MAY 28 2010

NCZ007>011-021>028-038>043-073>078-083>086-088-089-290930-
PERSON-GRANVILLE-VANCE-WARREN-HALIFAX-FORSYTH-GUILFORD-ALAMANCE-
ORANGE-DURHAM-FRANKLIN-NASH-EDGECOMBE-DAVIDSON-RANDOLPH-CHATHAM-WAKE-
JOHNSTON-WILSON-STANLY-MONTGOMERY-MOORE-LEE-HARNETT-WAYNE-ANSON-
RICHMOND-SCOTLAND-HOKE-CUMBERLAND-SAMPSON-
416 AM EDT FRI MAY 28 2010

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL NORTH CAROLINA.

.DAY ONE...TODAY AND TONIGHT.

A FEW STRONG TO SEVERE THUNDERSTORMS ARE EXPECTED TODAY AND THIS
EVENING AS A COLD FRONT DRIFTS SOUTHWESTWARD ACROSS THE REGION. THE
MAIN SEVERE WEATHER HAZARDS WILL BE DAMAGING DOWNBURST WINDS AND
LARGE HAIL UP TO THE SIZE OF QUARTERS. IN ADDITION...NEARLY
CONTINUOUS LIGHTNING STRIKES MAY OCCUR WITH THE STRONGER STORMS.

SINCE THE WINDS ALOFT ARE WEAK...THE LACKING OF A STEERING FLOW
WILL RESULT IN SLOW MOVING SHOWERS AND STORMS. THIS MAY LEAD TO
LOCALLY HEAVY RAINFALL WHICH MAY CAUSE BRIEF FLOODING OF SMALL
CREEKS...STREAMS AND POOR DRAINAGE AREAS.

THE THREAT FOR SEVERE THUNDERSTORMS WILL BE GREATEST BETWEEN 1 PM
AND 10 PM.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY.

HAZARDOUS WEATHER IS NOT EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SKYWARN SPOTTER ACTIVATION MAY BE NEEDED THIS AFTERNOON AND
EVENING.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE RALEIGH NC
528 PM EDT FRI MAY 28 2010

NCZ083-282215-
ANSON-
528 PM EDT FRI MAY 28 2010

...A STRONG THUNDERSTORM WILL MOVE ACROSS ANSON COUNTY THROUGH 615 PM
EDT...

AT 528 PM EDT...DOPPLER RADAR INDICATED A STRONG THUNDERSTORM OVER
POLKTON...OR ABOUT 6 MILES WEST OF WADESBORO...MOVING NORTHWEST AT 15
MPH.

SOME LOCATIONS AFFECTED BY THIS STORM INCLUDE...POLKTON AND
PEACHLAND.

HAZARDS INCLUDE...
PEA SIZE HAIL.
GUSTY WINDS OF 30 TO 40 MPH.

DON'T WAIT UNTIL YOU SEE THE FIRST LIGHTNING FLASH BEFORE HEADING TO
SAFETY. MOVE INDOORS AT THE FIRST SIGN OF THREATENING SKIES OR THE
FIRST SOUND OF THUNDER. MAKE SURE THAT LIGHTNING IS WELL AWAY FROM
YOUR LOCATION BEFORE RESUMING OUTDOOR ACTIVITY.

&&

LAT...LON 3519 8028 3520 8026 3520 8024 3516 8022
      3517 8019 3515 8017 3516 8015 3496 8005
      3488 8024 3496 8032
TIME...MOT...LOC 2128Z 151DEG 16KT 3497 8018

GIH

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE RALEIGH NC
537 PM EDT FRI MAY 28 2010

NCZ021-282215-
FORSYTH-
537 PM EDT FRI MAY 28 2010

...A STRONG THUNDERSTORM WILL MOVE ACROSS FORSYTH COUNTY THROUGH 615
PM EDT...

AT 536 PM EDT...DOPPLER RADAR INDICATED A STRONG THUNDERSTORM OVER
PFAFFTOWN...AND WAS NEARLY STATIONARY.

SOME LOCATIONS AFFECTED BY THIS STORM INCLUDE...PFAFFTOWN.

HAZARDS INCLUDE...
PEA SIZE HAIL.
GUSTY WINDS OF 30 TO 40 MPH.

SEEK SHELTER IN A NEARLY BUILDING OR VEHICLE. STRONG WINDS ARE
CAPABLE OF KNOCKING DOWN SMALL TREES AND BLOWING AROUND TRASH CANS...
POTTED PLANTS...LAWN FURNITURE AND OTHER LIGHT OUTDOOR OBJECTS.

&&

LAT...LON 3614 8045 3615 8045 3620 8045 3626 8034
      3626 8026 3626 8017 3610 8007 3602 8037
TIME...MOT...LOC 2136Z 243DEG 2KT 3614 8032

KRR

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE RALEIGH NC
600 PM EDT FRI MAY 28 2010

NCZ083-282230-
ANSON-
600 PM EDT FRI MAY 28 2010

...A STRONG THUNDERSTORM WILL MOVE ACROSS ANSON COUNTY THROUGH 630 PM
EDT...

AT 559 PM EDT...DOPPLER RADAR INDICATED A STRONG THUNDERSTORM OVER
ANSONVILLE...OR ABOUT 7 MILES NORTHWEST OF WADESBORO...MOVING
NORTHWEST AT 15 MPH.

SOME LOCATIONS AFFECTED BY THIS STORM INCLUDE ANSONVILLE... AND
HIGHWAY 52 NORTH OF WADESBORO.

HAZARDS INCLUDE...
PEA SIZE HAIL.
GUSTY WINDS OF 30 TO 40 MPH.
HEAVY RAINFALL AND MINOR FLOODING.

DON'T WAIT UNTIL YOU SEE THE FIRST LIGHTNING FLASH BEFORE HEADING TO
SAFETY. MOVE INDOORS AT THE FIRST SIGN OF THREATENING SKIES OR THE
FIRST SOUND OF THUNDER. MAKE SURE THAT LIGHTNING IS WELL AWAY FROM
YOUR LOCATION BEFORE RESUMING OUTDOOR ACTIVITY.

THIS STORM WILL PRODUCE HEAVY RAINFALL...WHICH WILL CAUSE MINOR
FLOODING OF LOW LYING AREAS INCLUDING DITCHES...CREEKS...ROADWAYS AND
AREAS OF POOR DRAINAGE. AVOID THESE AREAS AND DO NOT CROSS FLOODED
ROADS. MOTORISTS SHOULD ALSO REDUCE DRIVING SPEEDS TO AVOID
HYDROPLANING.

&&

LAT...LON 3519 8028 3520 8026 3520 8024 3516 8022
      3517 8019 3515 8017 3518 8015 3517 8013
      3519 8011 3515 8007 3510 8006 3509 8003
      3496 7992 3490 8013 3507 8030
TIME...MOT...LOC 2159Z 148DEG 11KT 3506 8014

GIH

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE RALEIGH NC
618 PM EDT FRI MAY 28 2010

NCZ021-282300-
FORSYTH-
618 PM EDT FRI MAY 28 2010

...A STRONG THUNDERSTORM WILL CONTINUE ACROSS FORSYTH COUNTY THROUGH
700 PM EDT...

AT 617 PM EDT...DOPPLER RADAR INDICATED A STRONG THUNDERSTORM OVER
PFAFFTOWN THAT WAS NEARLY STATIONARY.

SOME LOCATIONS AFFECTED BY THIS STORM INCLUDE...PFAFFTOWN...
WINSTON-SALEM.

HAZARDS INCLUDE...
PEA SIZE HAIL.
GUSTY WINDS OF 30 TO 40 MPH.
HEAVY RAINFALL AND MINOR FLOODING.

THIS STORM WILL PRODUCE HEAVY RAINFALL...WHICH WILL CAUSE MINOR
FLOODING OF LOW LYING AREAS INCLUDING DITCHES...CREEKS...ROADWAYS AND
AREAS OF POOR DRAINAGE. AVOID THESE AREAS AND DO NOT CROSS FLOODED
ROADS. MOTORISTS SHOULD ALSO REDUCE DRIVING SPEEDS TO AVOID
HYDROPLANING.

&&

LAT...LON 3626 8040 3626 8024 3618 8008 3603 8028
      3608 8048
TIME...MOT...LOC 2217Z 296DEG 2KT 3610 8033

KRR