Area Forecast Discussion
Issued by NWS Sterling, VA

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000
FXUS61 KLWX 061447
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1047 AM EDT MON JUL 6 2015

.SYNOPSIS...
A WARM FRONT WILL LIFT NORTH INTO THE AREA TODAY AS A LOW PRESSURE
SYSTEM WEAKENS OVER THE REGION. HIGH PRESSURE BRIEFLY BUILDS
TUESDAY. A WEAK COLD FRONT WILL THEN ENTER THE REGION TUESDAY
NIGHT...THEN LINGER THROUGH THE REST OF THE WEEK.

&&

.NEAR TERM /THROUGH TUESDAY/...
14Z SFC ANALYSIS SHOWING WEAK WARM FRONT EXTENDING ACROSS THE
AREA WHILE UPPER LVL TROUGH SLOWLY PUSHES EAST INTO THE MID
ATLANTIC. LATEST REFLECTIVITY SHOWING SPOTTY SHOWERS POPPING UP
ALONG FRONTAL BOUNDARY WITH SUPPORT FROM WEAK VORT MAX PLACED OVER
WESTERN MD. EXPECTING MOSTLY DRY CONDITIONS FOR MOST OF THE AREA
THRU THE MORNING...WITH INCRSG COVERAGE OF CONVECTION AFTR 18Z.

AFTR 18Z...FRONTAL BOUNDARY REMAINS NEARLY STATIONARY NEAR THE
MASON-DIXON LINE INTO THIS EVENING. AS THE UPPER LVL TROUGH PIVOTS
EAST...EXPECTING SHOWERS AND TSTMS TO FORM WEST OF THE BLUE RIDGE
AND ALONG THE FRONT OVER MD...PUSHING EAST LATE AFTN AND INTO THE
EVENING. CONCERNING SVR THREAT...MOST OF THE AREA REMAINS IN A
MARGINAL RISK WITH DAMAGING WINDS...HEAVY RAINFALL AND EVEN AN
ISO TORNADO PSBL. THINKING THE BEST TIMING WILL BE BTW 18-02Z TO
MAXIMIZE DIURNAL HEATING. CLOUDS LOOKING TO NOT SCATTER OUT
NEARLY AS ORIGINALLY THOUGHT...BUT ENOUGH DESTABILIZATION SHOULD
STILL OCCUR TO AID IN TSTM DEVELOPMENT. STRONG SURGE OF MOISTURE
ON GOING...WITH PWATS FROM 12Z SOUNDING AROUND 1.7 INCHES. WITH
THE GENERAL FLOW FROM THE S...COULD SEE TRAINING CELLS THIS
AFTN...AND WITH THE HIGHER MOISTURE...HEAVY RAIN IS EXPECTED.
HOWEVER...WITH THE SCT NATURE OF THE STORMS...ANY FLOODING/FLASH
FLOODING WILL BE LOCALIZED. BACKING WINDS RIGHT AROUND THE FRONTAL
BOUNDARY WILL ALSO HEIGHTEN THE TORNADO DEVELOPMENT
THREAT...MAINLY LATE AFTN.

THE AXIS OF THE REMNANT UPR TROUGH SHIFTS INTO THE AREA
TONIGHT... SHUNTING ACTIVITY EAST. KEPT SOME POPS NEAR THE
CHESAPEAKE THROUGH THE NIGHT. MIN TEMPS MILD...UPR 60S WEST OF THE
BLUE RIDGE...LOW 70S EAST.

TUESDAY...SWLY FLOW OVER THE AREA WITH A SWATH OF 20C 850 TEMPS
SUGGEST MID 90S IF THE CLOUDS CAN CLEAR. WENT GENERALLY LOW 90S...AN
INCREASE PREVIOUS FORECAST. DEWPOINTS IN THE MID/UPR 60S WOULD ADD A
FEW DEGREES IN A HEAT INDEX. ISOLATED TSTMS NEAR THE BAY BREEZE AND
IN THE TERRAIN. OTW...NVA BEHIND THE TROUGH LIMITS ACTIVITY.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
LOW LEVEL MOISTURE WILL INCREASE FROM THE SOUTH TUESDAY NIGHT
AHEAD OF A COLD FRONT FORECAST TO CROSS THE REGION ON WEDNESDAY.
THE FRONT WILL LIKELY BE ACCOMPANIED BY INCREASING CHANCES FOR
SHOWERS AND THUNDERSTORMS ESPECIALLY DURING THE AFTERNOON AND
EARLY EVENING. HIGH TEMPERATURES ON WEDNESDAY WILL LIKELY REACH
THE LOW TO MID 80S WEST TO THE UPPER 80S TO LOWER 90S EAST OF THE
BLUE RIDGE.

FRONT WILL PUSH OFFSHORE LATE WEDNESDAY NIGHT INTO THURSDAY
MORNING AND HIGH PRESSURE WILL BUILD IN BRIEFLY FOR THE FIRST PART
OF THURSDAY. THURSDAY WILL BE SLIGHTLY COOLER BUT THERE WILL STILL
BE A CHANCE FOR SCATTERED SHOWERS/STORMS DURING THE AFTERNOON AND
EVENING.

&&

.LONG TERM /FRIDAY THROUGH SUNDAY/...
MEDIUM TO LONG RANGE PATTERN FEATURES A RIDGE OF HIGH PRESSURE
OVER THE SOUTHEAST U.S WITH A SERIES OF WEAK UPPER DISTURBANCES
CROSSING THE REGION THROUGH THE WEEKEND. THIS WILL LEAD TO AT
LEAST OF CHANCE FOR SCATTERED AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS EACH DAY. HIGH TEMPERATURES IN THE 80S TO NEAR 90
CAN BE EXPECTED.

&&

.AVIATION /15Z MONDAY THROUGH FRIDAY/...
BKN-OVC MVFR-VFR CIGS CURRENTLY. EXPECTING CIGS TO BECOME ALL
VFR...AROUND 4-5 KFT...FOR THE AFTN. TSTMS MAINLY PSBL
18-02Z...THOUGH WILL BE SCT IN NATURE. SOME OF THE STORMS...ESP
NEAR DC/BALTIMORE...COULD RESULT IN STRONG WINDS IN EXCESS OF 40
KTS AND HEAVY RAINFALL. THE STORMS WILL ALSO DROP CONDITIONS TO
SUB-VFR AND PSBL IFR AT TIMES. LINGERING PCPN THIS
EVENING...CLEARING FROM WEST TO EAST OVERNIGHT. VFR CONDITIONS FOR
TUESDAY.

MOSTLY VFR CONDITIONS EXPECTED TUESDAY NIGHT THROUGH
FRIDAY...HOWEVER...AFTERNOON AND EVENING SCATTERED SHOWERS AND
THUNDERSTORMS WILL BE POSSIBLE EACH DAY WHICH COULD LOCALLY REDUCE
VISIBILITIES BELOW VFR. PATCHY OVERNIGHT FOG MAY ALSO BE POSSIBLE.

&&

.MARINE...
WARM FRONT LIFTS INTO THE AREA TODAY WITH SLY CHANNELING WITH 20 KT
GUSTS OVER SRN MD BAY WATERS LATE THIS AFTERNOON INTO THE OVERNIGHT
WHERE THERE IS AN SCA. 10 TO 15 KT ELSEWHERE. FLOW SHIFTS SWLY
TONIGHT AND 15 KT SWLY FLOW EXPECTED TUESDAY...WILL NEED TO WATCH
FOR SOME 18 KT GUSTS ACROSS THE WATERS.

WINDS ARE EXPECTED TO REMAIN BELOW SCA FOR MUCH OF THE MEDIUM TO
LONG RANGE PERIOD. OCCASIONAL AFTERNOON AND EVENING THUNDERSTORMS
WILL BE POSSIBLE THROUGH THE WEEKEND. ANY STORM THAT DOES DEVELOP
COULD PRODUCE GUSTY WINDS...LIGHTNING AND BRIEF HEAVY DOWNPOURS.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 5 PM THIS AFTERNOON TO 5 AM EDT
     TUESDAY FOR ANZ533-534-537-543.

&&

$$
SYNOPSIS...KRW
NEAR TERM...BAJ/SEARS
SHORT TERM...BAJ/KRW
LONG TERM...KRW
AVIATION...BAJ/KRW
MARINE...BAJ/KRW


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