Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 08/31/14
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1125 PM MDT THU AUG 28 2014
.UPDATE...
ISSUED AT 612 PM MDT THU AUG 28 2014
AS UPPER LOW PULLS AWAY TO THE EAST...SHOWERS AND THUNDERSTORMS
HAVE BEEN DECREASING EARLIER THAN GRIDS PORTRAYED FOR
NORTHERN/WESTERN PORTIONS OF THE FORECAST AREA. GRIDS WERE UPDATED
TO REFLECT EARLIER END TO PRECIPITATION. LATEST HRRR SUGGESTS THAT
PRECIPITATION SHOULD COME TO AN END FOR MOST AREAS SHORTLY AFTER
MIDNIGHT. -KT
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 238 PM MDT THU AUG 28 2014
CURRENTLY...
SCATTERED SHOWERS WERE MAINLY OVER THE GREATER PIKES PEAK REGION AND
C MTNS...WITH MOST OF THE ACTIVITY ON THE LIGHT SIDE. TEMPS ACROSS
THE REGION WERE ON THE COOL SIDE...WITH READING MAINLY IN THE 60S TO
LOWER 70S. WAT VAP IMGY SHOWS THE TROUGH ALOFT WAS OVER THE EASTERN
PLAINS OF CO AND WAS MOVING SLOWLY EAST.
SCATTERED SHOWERS WILL CONTINUE TO MOVE SOUTHEAST ON THE BACKSIDE OF
THE UPPER LOW THROUGH THE EARLY EVENING HOURS. AS HEATING
DECREASES...PRECIP WILL DECREASE WITH ONLY SOME ISOLD SHOWERS OVER
THE FAR E PLAINS BY LATE EVENING. WITH LIMITED CAPE...NOT EXPECTING
MUCH IN THE WAY OF STRONG STORM ACTIVITY OR HEAVY RAIN...AND ANY
STORMS SHOULD MOVE SOUTHEAST AT A STEADY CLIP.
FOR TOMORROW...AS UPPER TROUGH MOVE EAST AND HEIGHTS BEING TO
RISE...ALL GUIDANCE SHOWS AREAS DRYING OUT AND TEMPS WARMING UP INTO
THE 80S ACROSS THE PLAINS...60S AND 70S VALLEYS AND 40S AND 50S
MTNS. SHOWERS WILL MAINLY BE RELEGATED TO THE MTNS TOMORROW
AFTERNOON...WITH NEARLY ALL OF THE LOWER ELEVATIONS REMAINING DRY.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 238 PM MDT THU AUG 28 2014
...HOT AND DRY END OF AUGUST AND BEGINNING OF SEPTEMBER...
EXTENDED FORECAST NOT LOOKING TOO ACTIVE AT THIS POINT. AFTER THIS
CURRENT SYSTEM MOVES TO THE EAST OUR AREA WILL BE UNDER
STRENGTHENING W-SW FLOW...WHICH WILL TEND TO KEEP THE PLAINS ON THE
WARM SIDE AND MAINLY DRY. THERE WILL BE ENOUGH MID LEVEL MOISTURE FOR
SOME ISOLD STORMS OVER THE MTS...BUT NOT MUCH ELSEWHERE. SHOULD GET
INTO THE 90S OVER THE PLAINS FOR BOTH SAT AND SUN...WITH POPS
NEGLIGIBLE. MT AREAS WILL SEE COMFORTABLE 70S THIS WEEKEND.
AS THE JET STAYS MAINLY TO OUR NORTH...A SHORT WAVE TROUGH WILL PASS
THROUGH ON SUNDAY...BUT SHOULD HAVE LITTLE IMPACT OTHER THAN A SLIGHT
COOLING OFF FOR MONDAY. WE THEN STAY UNDER BROAD CYCLONIC TO ZONAL
FLOW AS THE JET REMAINS OVER THE NORTHERN ROCKIES INTO THE HIGH
PLAINS. A FEW WEAK DISTURBANCES WILL SET OFF SOME CONVECTION OVER KS
AND NE CO...POSSIBLY SNEAKING INTO NE PORTIONS OF OUR CWA...BUT FOR
THE MOST PART WE REMAIN ON THE DRY AND WARM SIDE.
DOES NOT LOOK LIKE ANY REAL RETURN OF THE MONSOON UNTIL POSSIBLY THE
LATTER PART OF NEXT WEEK...AS A DEEPER TROUGH BUILDS OVER THE PACNW
AND WE BEGIN TO SEE A RETURN OF SRLY FLOW ALOFT. NEXT WEEKEND LOOKS
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1119 PM MDT THU AUG 28 2014
VFR CONDITIONS EXPECTED OVERNIGHT AS SKIES CLEAR OUT BEHIND
THE DEPARTING SYSTEM. THERE MAY BE SOME ENHANCED NORTHERLY
DRAINAGE WINDS AT TIMES AT KCOS OVERNIGHT. ON FRIDAY THERE
WILL BE POCKETS OF WESTERLY WINDS 10-15 KTS IN THE MORNING
ALONG THE LEE OF THE SOUTHEAST MTS...HOWEVER WINDS WILL LIGHTEN
AND SHIFT AROUND TO THE SOUTH TO SOUTHEAST AT KCOS AND KPUB WITH
SPEEDS AROUND 10 KTS DURING THE AFTERNOON. KALS WILL SEE LIGHT
SOUTHERLY WINDS AROUND 10 KTS DEVELOP IN THE AFTERNOON. ISOLATED
THUNDERSTORMS WILL DEVELOP OVER THE MTNS AFTER 18Z THEN DRIFT TO
THE SOUTHEAST ACROSS THE ADJACENT PLAINS. KCOS HAS THE BEST CHANCE
OF SEEING -TSRA AFFECT THE TERMINAL SO HAVE INTRODUCED A VCTS
GROUP AFTER 21Z. ISOLATED -TSRA COULD AFFECT KALS AND KPUB...BUT
PROBABILITY LOOKS TOO LOW TO WARRANT INCLUSION IN THE TAF AT THIS
POINT.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KT
SHORT TERM...HODANISH
LONG TERM...ROSE
AVIATION...KT
AREA FORECAST DISCUSSION
NWS ALBANY NY
705 PM EDT SAT AUG 30 2014
.SYNOPSIS...
A SLOW MOVING COLD FRONT WILL BRING SHOWERS AND THUNDERSTORMS
LATE TONIGHT INTO SUNDAY...SOME POSSIBLY WITH HEAVY RAINFALL. WEAK
HIGH PRESSURE WILL BUILD IN LABOR DAY. IT WILL BE VERY WARM AND
HUMID AND MAINLY RAIN-FREE...BUT AN ADDITIONAL THUNDERSTORM CANNOT
BE RULED OUT. ANOTHER COLD FRONT IS EXPECTED TO BRING A CHANCE FOR
SHOWERS AND THUNDERSTORMS TUESDAY AND TUESDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 704 PM...LOWER CLOUDS COVER THE SOUTHERN THIRD OF THE ALBANY
FORECAST AREA WHILE HIGHER CLOUDS APPROACH FROM THE WEST. THERE IS
A BROKEN LINE OF SHOWERS AND THUNDERSTORMS TO THE WEST THAT
EXTENDS FROM NEAR BUFFALO TO ROCHESTER AND THEN NORTHEAST ACROSS
EASTERN LAKE ONTARIO. THESE SHOWERS AND STORMS ARE ONLY VERY
SLOWLY GETTING CLOSER TO THE FAR NORTHWEST PART OF HERKIMER AND
HAMILTON COUNTIES...BUT DECIDED TO PUT SLIGHT CHANCE POPS OVER
THAT AREA FOR THIS EVENING AS LATEST HRRR AND HIRESWRF MODELS HAVE SOME
SHOWERS SCRAPE THE FAR NORTHWEST. AFTER THOSE SHOWERS GO BY TO THE
NORTH LATER THIS EVENING...MODELS INDICATE DRY CONDITIONS TILL AFTER
MIDNIGHT. LOWS TONIGHT IN THE 60S.
JUST SOME MINOR TWEAKS TO THE FIRST 12 HOURS OF THE FORECAST BASED
ON RADAR...SATELLLITE...CURRENT OBS AND LATEST RUNS OF FORECAST MODELS.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
STILL SOME QUESTION AS TO HOW MUCH CLOUD COVER WILL BE OVER THE
REGION TOMORROW. SOUTHWEST BOUNDARY LAYER FLOW AND A LOOSENING
BOUNDARY LAYER THERMAL GRADIENT SHOULD PROMOTE SOME BREAKS IN
CLOUD COVER. THERE SHOULD ALSO BE BREAKS IN THE LEFTOVER
CONVECTIVE DEBRIS FROM CONVECTION IN THE GREAT LAKES AND WESTERN
NY/PA. CLOUD COVER CURRENTLY UPSTREAM IN THE OH VALLEY AND GREAT
LAKES IS SCATTERED TO BROKEN. SO WITH THE PROSPECTS FOR AT LEAST
SOME INTERVALS OF SUN...WITH RAPIDLY WARMING BOUNDARY LAYER
TEMPERATURES...HIGHS SOLIDLY IN THE 80S SUNDAY...BUT UPPER 70S
SOUTHERN ADIRONDACKS WHERE SHOWERS AND THUNDERSTORMS SHOULD AFFECT
EARLIER IN THE DAY.
UPPER DYNAMICS...ALONG WITH A LITTLE LOW LEVEL JET SEGMENT TRACKS
THROUGH THE REGION SUNDAY AND SUNDAY NIGHT. DEEP MOISTURE SEEN IN
THE SATELLITE DERIVED SOUNDER IMAGERY OF PWAT...IS SURGING NORTH
FROM THE MS/TN VALLEY. SO...COVERAGE OF SHOWERS AND SCATTERED
THUNDERSTORMS SHOULD INCREASE TO LIKELY IN THE AFTERNOON IN MOST
AREAS. LOCALLY HEAVY RAIN IS POSSIBLE AND WILL ADDRESS IN
HAZARDOUS WEATHER OUTLOOK...BUT NO WIDESPREAD OR HIGH IMPACT FLOOD
THREAT EXPECTED.
WEAK COLD FRONT EXITS SUNDAY NIGHT WITH JUST SOME LINGERING
SCATTERED SHOWERS AND THUNDERSTORMS...WITH THE BEST COVERAGE IN
THE MID HUDSON VALLEY...BERKSHIRES AND NW CT SUNDAY EVENING. SOME
QUESTION AS TO HOW FAR SOUTH THE WEAK LOW LEVEL BOUNDARY GETS...SO
SCATTERED SHOWERS AND THUNDERSTORMS COULD LINGER THROUGH MUCH OF
MONDAY IN THE MID HUDSON VALLEY AND NW CT...BUT JUST SCATTERED...
WITH ISOLATED AFTERNOON ACTIVITY ELSEWHERE. STILL...SOME PERIODS
OF SUNSHINE EXPECTED MONDAY...WITH PERHAPS MORE CLOUDS THAN SUN IN
THE MID HUDSON VALLEY AND NW CT. HIGHS MONDAY SOLIDLY IN THE 80S.
THERE COULD BE A LULL IN THE SHOWER AND THUNDERSTORM ACTIVITY
MONDAY NIGHT WITH PARTIAL CLEARING...BUT DEW POINTS ARE NOT
EXPECTED TO DROP MUCH IF ANY...SO LOWS MONDAY NIGHT IN THE 60S.
ANOTHER COLD FRONT APPROACHES TUESDAY...WITH A BIT BETTER BOUNDARY
LAYER FRONTOGENESIS AND THERMAL GRADIENT TRACKING TOWARD THE
REGION. CURRENT CONSENSUS ON TIMING SUGGESTS SOME SUNSHINE AND
DAYTIME HEATING AT LEAST TUESDAY MORNING...WITH THE LEADING EDGE
OF SCATTERED SHOWERS AND THUNDERSTORMS APPROACHING WESTERN AREAS
MIDDAY OR EARLY AFTERNOON TUESDAY...THEN AFFECTING THE REST OF THE
REGION THROUGH THE AFTERNOON. HIGHS TUESDAY SOLIDLY IN THE 80S.
THUNDERSTORMS TUESDAY COULD BE STRONG BASED ON THE POTENTIAL
INSTABILITY...THERMAL GRADIENT FORCING AND BOUNDARY LAYER WINDS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
MIDWEEK THROUGH THE END OF THE WORK WEEK WILL FEATURE DRY CONDITIONS
AS HIGH PRESSURE MOVES OVER THE FORECAST AREA BEHIND A COLD FRONT.
HOWEVER...A COLD FRONT ON SATURDAY WILL BRING A SHOWERY START FOR
THE BEGINNING OF THE WEEKEND.
TEMPERATURES WILL AVERAGE A FEW DEGREES ABOVE NORMAL...WITH HIGHS
FROM AROUND 70 DEGREES...TO THE LOWER AND MID 80S WEDNESDAY THROUGH
FRIDAY. SATURDAY WILL BE COOLER WITH HIGHS FROM THE MID 60S TO
AROUND 809 DEGREES.
NIGHTTIME LOWS WILL BE IN THE MID 50S TO UPPER 60S RANGE JUST PRIOR
TO THE COLD FRONT TUESDAY NIGHT. WEDNESDAY NIGHT LOWS WILL RANGE
FROM AROUND 50 DEGREES IN THE WESTERN ADIRONDACKS...TO NEAR 60
DEGREES DOWN THE HUDSON VALLEY. THEN READINGS SLOWLY BOUNCE BACK...
WITH LOWS FROM MAINLY THE LOWER AND MID 50S IN THE MOUNTAINS...TO
THE LOWER 60S DOWN THE HUDSON VALLEY.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS PREVAILING ACROSS THE TERMINALS THIS
AFTERNOON...HOWEVER AN EXPANSIVE AREA OF STRATUS CLOUDS IS
NOTICEABLY CREEPING TOWARDS THE AREA FROM PA/NJ INTO THE CATSKILLS
OF NY...COURTESY OF LOW LEVEL MOISTURE INCREASING WITH A SOUTH TO
SOUTHWEST FLOW. FOR NOW...MOST OF THE CIGS ARE IN VFR RANGE
ALTHOUGH MVFR CIGS HAVE BEEN NOTED ACROSS SOME HIGHER TERRAIN
AREAS. WILL MENTION SCT CLOUDS EARLY WITH CIGS DEVELOPING LATER
THIS AFTERNOON OR EARLY EVENING...FROM SOUTHWEST TO NORTHEAST
ACROSS THE AREA. CIGS EXPECTED TO LOWER TO MVFR RANGE THIS
EVENING...ESPECIALLY LATER THIS EVENING AS LOW LEVEL DEWPOINTS
CONTINUE TO RISE. OVERNIGHT MAINLY MVFR CONDITIONS EXPECTED WITH
OVC CIGS AND SOME MIST. HOWEVER...THERE IS A CHANCE OF SOME
OCCASIONAL IFR AT KPSF BUT CONFIDENCE NOT GREAT ENOUGH TO MENTION
IN TAF AT THIS TIME.
CIGS WILL ONLY SLOWLY RISE ON SUNDAY...BUT SHOULD STILL GENERALLY
REMAIN IN MVFR RANGE THROUGH 18Z SUNDAY. A COLD FRONT WILL
APPROACH FROM THE WEST BRINGING A THREAT OF MAINLY AFTERNOON
CONVECTION. WILL MENTION VCSH IN KGFL/KALB TAF PRIOR TO 18Z.
WINDS WILL BE SOUTHERLY AROUND 6-12 KT WITH SOME OCCASIONAL HIGHER
GUSTS. WIND SPEEDS WILL DECREASE TO AROUND 3-8 KT AFTER DARK.
WINDS WILL GENERALLY BE SOUTH-SOUTHWEST AROUND 5-10 KT ON SUNDAY.
OUTLOOK...
SUNDAY NIGHT: MODERATE OPERATIONAL IMPACT. SCATTERED SHRA...TSRA.
LABOR DAY: LOW OPERATIONAL IMPACT. ISOLATED SHRA...TSRA.
MONDAY NIGHT: LOW OPERATIONAL IMPACT. ISOLATED SHRA...TSRA.
TUESDAY: MODERATE OPERATIONAL IMPACT. SCATTERED SHRA...TSRA.
TUESDAY NIGHT: MODERATE OPERATIONAL IMPACT. SCATTERED SHRA...TSRA.
WEDNESDAY: NO OPERATIONAL IMPACT. NO SIG WX.
WEDNESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
THURSDAY: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.FIRE WEATHER...
LATE TONIGHT INTO SUNDAY A SLOW MOVING COLD FRONT WILL BRING A
ROUND OF SHOWERS AND THUNDERSTORMS...SOME POSSIBLY WITH HEAVY
RAINFALL. WEAK HIGH PRESSURE WILL BUILD IN LABOR DAY. IT WILL BE
VERY WARM HUMID AND MAINLY RAIN-FREE...BUT AN ADDITIONAL
THUNDERSTORM CANNOT BE RULED OUT. ANOTHER COLD FRONT IS
EXPECTED TO BRING A CHANCE FOR SHOWERS AND THUNDERSTORMS TUESDAY
AND TUESDAY NIGHT.
MINIMUM RH VALUES SHOULD BE BETWEEN 65 TO 75 PERCENT SUNDAY ASS
COVERAGE OF SHOWERS AND THUNDERSTORMS INCREASES. MINIMUM RH VALUES
MONDAY SHOULD BE 55 TO 65 PERCENT. MAXIMUM RH VALUES TONIGHT AND
TOMORROW NIGHT ARE EXPECTED TO BE 80 TO 100 PERCENT WITH SOME DEW
FORMATION.
THE SURFACE WIND BE SOUTH TO SOUTHWEST AT 15 MPH OR LESS TONIGHT
THROUGH SUNDAY NIGHT...THEN BECOME WEST TO SOUTHWEST MONDAY.
&&
.HYDROLOGY...
SHOWERS AND THUNDERSTORMS WILL DEVELOP LATE TONIGHT AND
ESPECIALLY SUNDAY INTO SUNDAY EVENING. AVERAGE BASIN RAINFALLS
LOOK TO GENERALLY BE UNDER AN INCH SO AT THIS POINT...MAIN STREAM
RIVERS WILL GENERALLY SEE LITTLE OR NO RISES.
HOWEVER...WITH PWAT VALUES FORECAST TO INCREASE TO 2 INCHES...ANY
THUNDERSTORM COULD CONTAIN LOCALLY HEAVY RAINFALL EASILY EXCEEDING
AN INCH. ANY TRAINING THUNDERSTORMS COULD RESULT LOCALIZED PONDING
OF WATER IN AREAS OF POOR DRAINAGE.
ADDITIONAL THUNDERSTORMS ON LABOR DAY LOOK ISOLATED AND GENERALLY
NOT EXPECTED TO PRODUCE ADDITIONAL HYDRO PROBLEMS.
MORE SHOWERS AND THUNDERSTORMS ARE POSSIBLE LATE TUESDAY INTO
WEDNESDAY AS A STRONGER COLD FRONT ARRIVES.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...SND/NAS
NEAR TERM...SND
SHORT TERM...NAS
LONG TERM...ELH
AVIATION...JPV
FIRE WEATHER...NAS
HYDROLOGY...NAS
AREA FORECAST DISCUSSION...UPDATED
NWS COLUMBIA SC
1013 AM EDT FRI AUG 29 2014
.SYNOPSIS...
A BUILDING UPPER RIDGE WILL KEEP VERY WARM TEMPERATURES IN THE
FORECAST THROUGH EARLY NEXT WEEK. MOISTURE WILL INCREASE OVER THE
WEEKEND INTO EARLY NEXT WEEK BRINGING BACK A LOW CHANCE OF
AFTERNOON THUNDERSTORMS AND HIGHER HUMIDITY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
BACKDOOR COLD FRONT PUSHED INTO SOUTHERN NORTH CAROLINA OVERNIGHT
AND LOOKS TO BE SITUATED FROM NEAR GREENVILLE TO LANCASTER
EASTWARD TOWARDS NEWPORT NC WITH SURFACE WINDS FROM THE NORTH
BEHIND THE FRONT. MOST OF THE ATMOSPHERIC MOISTURE IS POOLED ALONG
THE BOUNDARY WITH THE BEST 925MB MOISTURE ACROSS SOUTHERN NC AND
HIGHEST PRECIPITABLE WATER ALSO EXTENDING ACROSS CENTRAL NORTH
CAROLINA. HIGH RESOLUTION MODEL DATA FROM HRRR AND SPC WRF
INDICATE ISOLATED CONVECTION IN THE VICINITY OF THE FRONT OVER
SOUTHERN NC BUT THE FORECAST AREA SHOULD REMAIN RAIN FREE ONCE
AGAIN. THE BOUNDARY IS QUITE SHALLOW AND LIKELY WILL MIX OUT AND
BECOME RE-ESTABLISHED FURTHER NORTH OVER CENTRAL NC BY AFTERNOON.
TEMPERATURES TODAY WILL QUICKLY RISE THROUGH THE 80S AND PEAK IN
THE MID TO POSSIBLE UPPER 90S THIS AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
UNDER MOSTLY CLEAR SKIES AND A SLIGHT INCREASE IN LOW-LEVEL
MOISTURE...LOWS TONIGHT WILL ONLY FALL INTO THE UPPER 60S. FOR
SATURDAY THE UPPER RIDGE REMAINS ACROSS THE AREA. MUCH OF THE
FORECAST AREA SHOULD REMAIN DRY ONCE AGAIN ON SATURDAY. LOW-LEVEL
MOISTURE CONTINUES TO INCREASE THROUGH THE DAY...BUT THE BEST
MOISTURE AND RAIN SHOULD REMAIN ACROSS THE EXTREME WESTERN
PORTIONS OF THE CWA. WILL CARRY A SLIGHT CHANCE FOR RAIN ACROSS
THE WEST...BUT CONFIDENCE NOT HIGH. MODELS CONTINUE TO TREND DRIER
FOR SATURDAY. CONTINUE WARM TEMPERATURES AS READINGS REMAIN ABOVE
NORMAL. FOR SATURDAY NIGHT...WILL HOLD ONTO THE SLIGHT CHANCE
EARLY IN THE EVENING...THEN EXPECTING CONDITIONS TO DRY OUT FOR
THE REMAINDER OF THE NIGHT.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
UPPER RIDGE CONTINUES OVER THE AREA THROUGH THE EXTENDED PERIOD.
LOW-LEVEL MOISTURE CONTINUES TO SLOWLY INCREASE THROUGH THE
REMAINDER OF THE WEEKEND AND INTO EARLY NEXT WEEK WITH SOUTHEAST
FLOW OFF THE ATLANTIC. EXPECT A LOW CHANCE OF SHOWERS AND
THUNDERSTORMS THROUGH THE MIDDLE OF NEXT WEEK. AT THIS TIME IT
APPEARS THAT ANY SHOWERS AND THUNDERSTORMS WILL BE MAINLY
DIURNALLY DRIVEN WITH LITTLE UPPER LEVEL FORCING. TEMPERATURES
WILL CONTINUE ABOVE NORMAL THROUGH THE REMAINDER OF THE LONG TERM
PERIOD.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
ATMOSPHERE REMAINS DRY. EXPECT VFR CONDITIONS TODAY. AN UPPER
RIDGE AND DRY AND CAPPED ATMOSPHERE WILL REMAIN IN PLACE AND
CONTINUE TO PRECLUDE ANY CONVECTION CONCERNS. LIGHT SOUTHEAST
WINDS EXPECTED THROUGH THE PERIOD. FOG LOOKS TO BE MORE LIKELY
TONIGHT AS LOW LEVEL MOISTURE INCREASES WITH THE SOUTHEAST FLOW.
EXTENDED AVIATION OUTLOOK...LATE NIGHT AND EARLY MORNING STRATUS AND
FOG POSSIBLE. SCATTERED MAINLY AFTERNOON THUNDERSTORMS SUNDAY
THROUGH TUESDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
NEAR TERM...HC
AVIATION...HC
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1014 PM CDT SAT AUG 30 2014
.DISCUSSION...
221 PM CDT
SYNOPSIS...SCATTERED THUNDERSTORMS ARE POSSIBLE NW OF I-55 WHILE A
LINE OF STORMS WILL IMPACT AREAS ALONG AND EAST OF I-55 THROUGH THIS
EVENING. TOMORROW WILL BE DRY BUT UNSETTLED WEATHER RETURNS MONDAY
WITH MULTIPLE CHANCES FOR THUNDERSTORMS. SEVERE STORMS ARE POSSIBLE
MONDAY. TEMPERATURES WILL BE ABOVE NORMAL THROUGH THE PERIOD WITH A
COUPLE DAYS GETTING INTO THE MID 80S.
THROUGH TONIGHT...
AN UPPER LEVEL TROUGH IS OVER THE UPPER MISSISSIPPI RIVER VALLEY AND
IT WILL PASS OVER THE REGION THROUGH THIS EVENING. A SURFACE LOW IS
OVER THE NORTHERN END OF LAKE MI WITH ITS COLD FRONT EXTENDING
THROUGH WI AND EASTERN IA. THE LOW WILL CONTINUE NE THROUGH THE
NIGHT.
HAVE MUCH HIGHER CONFIDENCE IN THE CONVECTIVE FORECAST TODAY
COMPARED TO YESTERDAY DUE TO CLEAR FORCING MECHANISMS. EXPECTING TO
HAVE TWO AREAS TO MONITOR. THE FIRST IS NORTHWEST OF I-55 WHERE
ISOLATED TO SCATTERED STORMS WILL CONTINUE TO FESTER THROUGH THIS
AFTERNOON AHEAD OF UPPER LEVEL WAVE AND COLD FRONT.
THE BIGGER CONCERN WILL BE ALONG AND SE OF I-55 WHERE A LINE OF
SHOWERS AND STORMS HAS ALREADY DEVELOPED. THE LATEST RAP ANALYSIS
SHOWS A NICE CORRIDOR OF MOISTURE CONVERGENCE WHERE THE CONVECTION
HAS FIRED. THE LATEST AMDAR SOUNDINGS ARE CAPLESS WITH 1000-1500
J/KG OF CAPE. HOWEVER...LAPSE RATES ARE POOR AND WIND SHEAR IS
MINIMAL AT BEST. THE AMDAR SOUNDINGS DO HAVE LOW LEVEL INVERTED
V/S AND THE RAP ANALYSIS HAS AROUND 1000 J/KG OF DOWNDRAFT CAPE.
THEREFORE NOT EXPECTING WIDESPREAD SEVERE WEATHER...BUT A STORM OR
TWO MAY PULSE UP AND PRODUCE SEVERE WINDS.
HEAVY DOWNPOURS ARE ALSO EXPECTED WITH PWAT VALUES OF 1.6-1.8
INCHES. BASED ON SHORT TERM GUIDANCE...THE AREA MOST CONCERNING IS
SOUTH OF A VALPARAISO IN TO GIBSON CITY IL LINE. STORMS WILL
CONTINUE TO DEVELOP AND MOVE OVER THIS REGION WITH AMPLE FORCING.
THEREFORE IF STORMS TRAIN OVER THE SAME AREA FOR AN EXTENDED PERIOD
OF TIME...FLASH FLOODING MAY OCCUR.
STORMS DIMINISH AND PUSH EAST OVERNIGHT WHILE HIGH PRESSURE SPREADS
OVER THE REGION. WINDS WILL DIMINISH AND FOG IS POSSIBLE.
SUNDAY...
SUNDAY LOOKS DRY WITH HIGH PRESSURE OVER THE REGION. WE WILL BE IN
THE NEXT LOW/S WARM SECTOR WITH 850MB TEMPS AROUND 18C. THEREFORE
RAISED HIGH TEMPS INTO THE MID 80S AWAY FROM THE LAKE. THE WEAK
PRESSURE GRADIENT WILL ALLOW A LAKE BREEZE TO FORM AND KEEP THE IL
LAKEFRONT AROUND 80. GUIDANCE HAS SLOWED THE NEXT LOW SO PUSHED
BACK POPS SUNDAY NIGHT.
JEE
MONDAY...
UPPER WAVE DIGGING TOWARDS THE INTER-MOUNTAIN WEST THIS AFTERNOON
WILL LIFT ACROSS THE PLAINS INTO THE UPPER MIDWEST ON MONDAY WITH
ATTENDANT SURFACE LOW DEEPENING AS IT LIFTS ACROSS ONTARIO TO NEAR
JAMES BAY BY LATE MONDAY. A SURFACE FRONT WILL SLOWLY PUSH ACROSS
THE REGION MONDAY AND GUIDANCE HAS TRENDED TOWARDS A SLOWER SOLUTION
OVER THE LAST 24 HOURS. MODERATE TO STRONG INSTABILITY IS PROGGED TO
DEVELOP ALONG AND AHEAD OF THE FRONT WHERE THE GFS ADVERTISES A
CORRIDOR OF JUST OVER 2000 J/KG MLCAPE JUST TO THE WEST OF THE CWA
MONDAY AFTERNOON. THE BETTER CONVERGENCE ASSOCIATED WITH THE COLD
FRONT MAY ARRIVE JUST PAST THE MOST FAVORABLE DIURNAL TIMING IF
TIMING TRENDS HOLD TRUE...BUT THE RIGHT ENTRANCE REGION TO THE UPPER
JET IS PROGGED TO MOVE OVER THE AREA BY MID TO LATE IN THE EVENING
WITH DEEP LAYER SHEAR VALUES INCREASING TO AROUND 40 KT OR SO WHICH
WOULD BE SUFFICIENT FOR AN ORGANIZED SEVERE WEATHER THREAT...THOUGH
THIS THREAT SHOULD DIMINISH WEST TO EAST AS WE GET LATER INTO THE
OVERNIGHT HOURS AND THE BOUNDARY LAYER STABILIZES.
TUESDAY THROUGH THURSDAY...
A SECONDARY SHORTWAVE TROUGH IS PROGGED TO PUSH ACROSS THE REGION ON
TUESDAY BRINGING ADDITIONAL CHANCES FOR SHOWER AND THUNDERSTORMS
MAINLY ACROSS SOUTH/SOUTHEASTERN PORTIONS OF THE CWA WHERE THE
FRONTAL BOUNDARY MAY STILL SLOWLY BE MAKING A PUSH. MODERATE TO
STRONG HEIGHTS RISES QUICKLY BUILD IN BEHIND THIS FEATURE THOUGH AND
SHOULD RESULT IN A DRY WEATHER FOR MOST OF THE FORECAST AREA
TUESDAY. THE GFS IS PARTICULAR IS HOLDING ONTO SOME POPS NORTH OF
THE BOUNDARY WEDNESDAY INTO THURSDAY WHERE PERSISTENT WARM ADVECTION
WILL RESULT IN MID LEVEL ASCENT...THOUGH THE ECMWF REMAINS DRY THIS
PERIOD. WILL MAINTAIN SLIGHT CHANCE POPS IN THE MEANTIME.
FRIDAY THROUGH SATURDAY...
THERMAL RIDGE IS EXPECTED TO MOVE BACK OVERHEAD LATE IN THE WEEK
WITH H85 TEMPS PUSHING INTO THE LOW 20C RANGE WHICH WILL LEAD TO
ANOTHER WARM UP WITH TEMPS INTO THE UPPER 80S. ANOTHER SLOW MOVING
COLD FRONT WILL THEN SAG SOUTH ACROSS THE REGION BRINGING RENEWED
CHANCES FOR SHOWERS AND THUNDERSTORMS.
DEUBELBEISS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 03Z...
* SLIGHT CHANCE OF FOG/STRATUS EARLY SUNDAY MORNING
* CHANCE LAKE BREEZE/WIND SHIFT EASTERLY LATE SUNDAY AFTERNOON
IZZI
//DISCUSSION...UPDATED 00Z...
SCT`D TSRA WILL CONTINUE THIS EVENING TO THE SOUTHEAST OF THE
TERMINALS...WITH VFR CONDITIONS EXPECTED CLOSER TO THE TERMINALS.
THE TSRA ARE OCCURRING NEAR AND JUST AHEAD OF A WEAK FRONT JUST
SOUTH OF THE TERMINALS WITH SLIGHTLY DRIER/LESS HUMID AIR TO THE
NORTH OF THE FRONT. GIVEN THE LACK OF RAIN TODAY AND MIXING OUT OF
LOW LEVEL MOISTURE...PLUS THE URBAN HEAT ISLAND EFFECTS...NOT
ANTICIPATING FOG/STRATUS TO BE MUCH OF AN ISSUE FOR THE CHICAGO
TERMINALS. MODEL GUIDANCE IS STILL HITTING THE THREAT OF IFR
CIGS/VSBY PRETTY HARD...BUT CONDITIONAL CLIMO SUGGESTS THE CHANCES
OF IFR TOMORROW MORNING GIVEN CURRENT CONDITIONS IS FAR LESS THAN
10% SO HAVE GONE WITH VFR FOR MDW/ORD. MAINTAINED MVFR/IFR FOG AT
THE MORE FOG PRONE OUTLYING TERMINALS...PARTICULARLY GYY AND DPA.
ANY VSBY RESTRICTIONS/FOG THAT DOES FORM OVERNIGHT WILL QUICKLY
DISSIPATE BY MID MORNING SUNDAY WITH VFR CONDITIONS EXPECTED THE
REMAINDER OF THE DAY. WINDS SHOULD REMAIN LIGHT ENOUGH TO ALLOW A
LAKE BREEZE TO DEVELOP...BUT IF IT WERE TO THREATEN ORD/MDW IT
LIKELY WOULDN`T DO SO UNTIL VERY LATE IN THE AFTERNOON OR TOWARD
EARLY EVENING.
IZZI
//ORD AND MDW CONFIDENCE...UPDATED 03Z...
* MEDIUM-HIGH CONFIDENCE IN NO IFR AT ORD/MDW OVERNIGHT
* LOW-MEDIUM CONFIDENCE IN POTENTIAL LAKE BREEZE SUNDAY AFTERNOON
* HIGH CONFIDENCE IN ALL OTHER ELEMENTS
IZZI
//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...
MONDAY...PERIOD OR TWO OF SHRA/TSRA...STRONG TSRA POSSIBLE.
TUESDAY AND WEDNESDAY...PREDOMINANTLY VFR.
THURSDAY...SLIGHT CHANCE TSRA...OTHERWISE VFR.
FRIDAY...CHANCE TSRA.
IZZI
&&
.MARINE...
221 PM CDT
MODERATE SOUTHWEST FLOW IS CURRENTLY IN PLACE ACROSS LAKE MICHIGAN
WHERE SOUTHWEST WINDS ARE GUSTING 20 TO 25 KTS WITH OCCASIONAL 30 KT
WINDS. A SMALL CRAFT ADVISORY HAS BEEN ISSUED FOR THE NEARSHORE
WATERS THROUGH LATE THIS EVENING. THIS IS AHEAD OF LOW PRESSURE
CURRENTLY CENTERED NEAR GREEN BAY. THE LOW WILL DRAG A COLD FRONT
SOUTH ACROSS LAKE MICHIGAN TONIGHT TURNING WINDS TO THE NORTHWEST.
WINDS WILL ABATE BRIEFLY AS TRANSIENT HIGH PRESSURE PUSHES ACROSS
THE NORTHERN LAKES REGION...BUT BY MIDDAY SUNDAY WINDS ARE EXPECTED
TO BEGIN TO TURN SOUTHEAST AND START TO RAMP UP AGAIN AHEAD OF
ANOTHER AREA OF LOW PRESSURE. THIS NEXT WILL LOW LIFT FROM THE
NORTHERN PLAINS...DEEPENING AS IT HEADS TO HUDSON BAY MONDAY NIGHT
INTO TUESDAY. SOUTH WINDS ARE EXPECTED TO PEAK MONDAY OVER THE LAKE
WITH GUSTS SOLIDLY INTO THE 20 KT RANGE...APPROACHING 30 KT OVER THE
NORTH END OF THE LAKE. ANOTHER COLD FRONT WILL SAG SOUTH ACROSS LAKE
MICHIGAN MONDAY NIGHT.
DEUBELBEISS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
637 PM CDT SAT AUG 30 2014
.DISCUSSION...
221 PM CDT
SYNOPSIS...SCATTERED THUNDERSTORMS ARE POSSIBLE NW OF I-55 WHILE A
LINE OF STORMS WILL IMPACT AREAS ALONG AND EAST OF I-55 THROUGH THIS
EVENING. TOMORROW WILL BE DRY BUT UNSETTLED WEATHER RETURNS MONDAY
WITH MULTIPLE CHANCES FOR THUNDERSTORMS. SEVERE STORMS ARE POSSIBLE
MONDAY. TEMPERATURES WILL BE ABOVE NORMAL THROUGH THE PERIOD WITH A
COUPLE DAYS GETTING INTO THE MID 80S.
THROUGH TONIGHT...
AN UPPER LEVEL TROUGH IS OVER THE UPPER MISSISSIPPI RIVER VALLEY AND
IT WILL PASS OVER THE REGION THROUGH THIS EVENING. A SURFACE LOW IS
OVER THE NORTHERN END OF LAKE MI WITH ITS COLD FRONT EXTENDING
THROUGH WI AND EASTERN IA. THE LOW WILL CONTINUE NE THROUGH THE
NIGHT.
HAVE MUCH HIGHER CONFIDENCE IN THE CONVECTIVE FORECAST TODAY
COMPARED TO YESTERDAY DUE TO CLEAR FORCING MECHANISMS. EXPECTING TO
HAVE TWO AREAS TO MONITOR. THE FIRST IS NORTHWEST OF I-55 WHERE
ISOLATED TO SCATTERED STORMS WILL CONTINUE TO FESTER THROUGH THIS
AFTERNOON AHEAD OF UPPER LEVEL WAVE AND COLD FRONT.
THE BIGGER CONCERN WILL BE ALONG AND SE OF I-55 WHERE A LINE OF
SHOWERS AND STORMS HAS ALREADY DEVELOPED. THE LATEST RAP ANALYSIS
SHOWS A NICE CORRIDOR OF MOISTURE CONVERGENCE WHERE THE CONVECTION
HAS FIRED. THE LATEST AMDAR SOUNDINGS ARE CAPLESS WITH 1000-1500
J/KG OF CAPE. HOWEVER...LAPSE RATES ARE POOR AND WIND SHEAR IS
MINIMAL AT BEST. THE AMDAR SOUNDINGS DO HAVE LOW LEVEL INVERTED
V/S AND THE RAP ANALYSIS HAS AROUND 1000 J/KG OF DOWNDRAFT CAPE.
THEREFORE NOT EXPECTING WIDESPREAD SEVERE WEATHER...BUT A STORM OR
TWO MAY PULSE UP AND PRODUCE SEVERE WINDS.
HEAVY DOWNPOURS ARE ALSO EXPECTED WITH PWAT VALUES OF 1.6-1.8
INCHES. BASED ON SHORT TERM GUIDANCE...THE AREA MOST CONCERNING IS
SOUTH OF A VALPARAISO IN TO GIBSON CITY IL LINE. STORMS WILL
CONTINUE TO DEVELOP AND MOVE OVER THIS REGION WITH AMPLE FORCING.
THEREFORE IF STORMS TRAIN OVER THE SAME AREA FOR AN EXTENDED PERIOD
OF TIME...FLASH FLOODING MAY OCCUR.
STORMS DIMINISH AND PUSH EAST OVERNIGHT WHILE HIGH PRESSURE SPREADS
OVER THE REGION. WINDS WILL DIMINISH AND FOG IS POSSIBLE.
SUNDAY...
SUNDAY LOOKS DRY WITH HIGH PRESSURE OVER THE REGION. WE WILL BE IN
THE NEXT LOW/S WARM SECTOR WITH 850MB TEMPS AROUND 18C. THEREFORE
RAISED HIGH TEMPS INTO THE MID 80S AWAY FROM THE LAKE. THE WEAK
PRESSURE GRADIENT WILL ALLOW A LAKE BREEZE TO FORM AND KEEP THE IL
LAKEFRONT AROUND 80. GUIDANCE HAS SLOWED THE NEXT LOW SO PUSHED
BACK POPS SUNDAY NIGHT.
JEE
MONDAY...
UPPER WAVE DIGGING TOWARDS THE INTERMOUNTAIN WEST THIS AFTERNOON
WILL LIFT ACROSS THE PLAINS INTO THE UPPER MIDWEST ON MONDAY WITH
ATTENDANT SURFACE LOW DEEPENING AS IT LIFTS ACROSS ONTARIO TO NEAR
JAMES BAY BY LATE MONDAY. A SURFACE FRONT WILL SLOWLY PUSH ACROSS
THE REGION MONDAY AND GUIDANCE HAS TRENDED TOWARDS A SLOWER SOLUTION
OVER THE LAST 24 HOURS. MODERATE TO STRONG INSTABILITY IS PROGGED TO
DEVELOP ALONG AND AHEAD OF THE FRONT WHERE THE GFS ADVERTISES A
CORRIDOR OF JUST OVER 2000 J/KG MLCAPE JUST TO THE WEST OF THE CWA
MONDAY AFTERNOON. THE BETTER CONVERGENCE ASSOCIATED WITH THE COLD
FRONT MAY ARRIVE JUST PAST THE MOST FAVORABLE DIURNAL TIMING IF
TIMING TRENDS HOLD TRUE...BUT THE RIGHT ENTRANCE REGION TO THE UPPER
JET IS PROGGED TO MOVE OVER THE AREA BY MID TO LATE IN THE EVENING
WITH DEEP LAYER SHEAR VALUES INCREASING TO AROUND 40 KT OR SO WHICH
WOULD BE SUFFICIENT FOR AN ORGANIZED SEVERE WEATHER THREAT...THOUGH
THIS THREAT SHOULD DIMINISH WEST TO EAST AS WE GET LATER INTO THE
OVERNIGHT HOURS AND THE BOUNDARY LAYER STABILIZES.
TUESDAY THROUGH THURSDAY...
A SECONDARY SHORTWAVE TROUGH IS PROGGED TO PUSH ACROSS THE REGION ON
TUESDAY BRINGING ADDITIONAL CHANCES FOR SHOWER AND THUNDERSTORMS
MAINLY ACROSS SOUTH/SOUTHEASTERN PORTIONS OF THE CWA WHERE THE
FRONTAL BOUNDARY MAY STILL SLOWLY BE MAKING A PUSH. MODERATE TO
STRONG HEIGHTS RISES QUICKLY BUILD IN BEHIND THIS FEATURE THOUGH AND
SHOULD RESULT IN A DRY WEATHER FOR MOST OF THE FORECAST AREA
TUESDAY. THE GFS IS PARTICULAR IS HOLDING ONTO SOME POPS NORTH OF
THE BOUNDARY WEDNESDAY INTO THURSDAY WHERE PERSISTENT WARM ADVECTION
WILL RESULT IN MID LEVEL ASCENT...THOUGH THE ECMWF REMAINS DRY THIS
PERIOD. WILL MAINTAIN SLIGHT CHANCE POPS IN THE MEANTIME.
FRIDAY THROUGH SATURDAY...
THERMAL RIDGE IS EXPECTED TO MOVE BACK OVERHEAD LATE IN THE WEEK
WITH H85 TEMPS PUSHING INTO THE LOW 20C RANGE WHICH WILL LEAD TO
ANOTHER WARM UP WITH TEMPS INTO THE UPPER 80S. ANOTHER SLOW MOVING
COLD FRONT WILL THEN SAG SOUTH ACROSS THE REGION BRINGING RENEWED
CHANCES FOR SHOWERS AND THUNDERSTORMS.
DEUBELBEISS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* SLIGHT CHANCE OF FOG/STRATUS EARLY SUNDAY MORNING
IZZI
//DISCUSSION...UPDATED 00Z...
SCT`D TSRA WILL CONTINUE THIS EVENING TO THE SOUTHEAST OF THE
TERMINALS...WITH VFR CONDITIONS EXPECTED CLOSER TO THE TERMINALS.
THE TSRA ARE OCCURRING NEAR AND JUST AHEAD OF A WEAK FRONT JUST
SOUTH OF THE TERMINALS WITH SLIGHTLY DRIER/LESS HUMID AIR TO THE
NORTH OF THE FRONT. GIVEN THE LACK OF RAIN TODAY AND MIXING OUT OF
LOW LEVEL MOISTURE...PLUS THE URBAN HEAT ISLAND EFFECTS...NOT
ANTICIPATING FOG/STRATUS TO BE MUCH OF AN ISSUE FOR THE CHICAGO
TERMINALS. MODEL GUIDANCE IS STILL HITTING THE THREAT OF IFR
CIGS/VSBY PRETTY HARD...BUT CONDITIONAL CLIMO SUGGESTS THE CHANCES
OF IFR TOMORROW MORNING GIVEN CURRENT CONDITIONS IS FAR LESS THAN
10% SO HAVE GONE WITH VFR FOR MDW/ORD. MAINTAINED MVFR/IFR FOG AT
THE MORE FOG PRONE OUTLYING TERMINALS...PARTICULARLY GYY AND DPA.
ANY VSBY RESTRICTIONS/FOG THAT DOES FORM OVERNIGHT WILL QUICKLY
DISSIPATE BY MID MORNING SUNDAY WITH VFR CONDITIONS EXPECTED THE
REMAINDER OF THE DAY. WINDS SHOULD REMAIN LIGHT ENOUGH TO ALLOW A
LAKE BREEZE TO DEVELOP...BUT IF IT WERE TO THREATEN ORD/MDW IT
LIKELY WOULDN`T DO SO UNTIL VERY LATE IN THE AFTERNOON OR TOWARD
EARLY EVENING.
IZZI
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* LOW-MEDIUM CONFIDENCE IN CONDITIONS REMAINING VFR OVERNIGHT AND
MEDIUM-HIGH CONFIDENCE IN NO PREVAILING IFR AT ORD/MDW OVERNIGHT
* MEDIUM CONFIDENCE IN NO WIND SHIFT TO EASTERLY WITH LAKE BREEZE
SUNDAY AFTERNOON AT ORD/MDW
* HIGH CONFIDENCE IN ALL OTHER ELEMENTS
IZZI
//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...
MONDAY...PERIOD OR TWO OF SHRA/TSRA...STRONG TSRA POSSIBLE.
TUESDAY AND WEDNESDAY...PREDOMINANTLY VFR.
THURSDAY...SLIGHT CHANCE TSRA...OTHERWISE VFR.
FRIDAY...CHANCE TSRA.
IZZI
&&
.MARINE...
221 PM CDT
MODERATE SOUTHWEST FLOW IS CURRENTLY IN PLACE ACROSS LAKE MICHIGAN
WHERE SOUTHWEST WINDS ARE GUSTING 20 TO 25 KTS WITH OCCASIONAL 30 KT
WINDS. A SMALL CRAFT ADVISORY HAS BEEN ISSUED FOR THE NEARSHORE
WATERS THROUGH LATE THIS EVENING. THIS IS AHEAD OF LOW PRESSURE
CURRENTLY CENTERED NEAR GREEN BAY. THE LOW WILL DRAG A COLD FRONT
SOUTH ACROSS LAKE MICHIGAN TONIGHT TURNING WINDS TO THE NORTHWEST.
WINDS WILL ABATE BRIEFLY AS TRANSIENT HIGH PRESSURE PUSHES ACROSS
THE NORTHERN LAKES REGION...BUT BY MIDDAY SUNDAY WINDS ARE EXPECTED
TO BEGIN TO TURN SOUTHEAST AND START TO RAMP UP AGAIN AHEAD OF
ANOTHER AREA OF LOW PRESSURE. THIS NEXT WILL LOW LIFT FROM THE
NORTHERN PLAINS...DEEPENING AS IT HEADS TO HUDSON BAY MONDAY NIGHT
INTO TUESDAY. SOUTH WINDS ARE EXPECTED TO PEAK MONDAY OVER THE LAKE
WITH GUSTS SOLIDLY INTO THE 20 KT RANGE...APPROACHING 30 KT OVER THE
NORTH END OF THE LAKE. ANOTHER COLD FRONT WILL SAG SOUTH ACROSS LAKE
MICHIGAN MONDAY NIGHT.
DEUBELBEISS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 11 PM SATURDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
420 PM CDT FRI AUG 29 2014
.MESOSCALE DISCUSSION...
411 PM CDT
THUNDERSTORMS ARE GENERALLY ISOLATED IN NORTHEAST ILLNOIS THIS
AFTERNOON WITH SCATTERED ACTIVITY EAST OF INTERSTATE 57 IN
ILLNOIS AND ALONG THE INTERSTATE CORRIDOR IN NW INDIANA. RADAR
ESTIMATES A QUICK THREE QUARTERS OF AN INCH TO 1 INCH HAS FALLEN
IN THE HEAVIER DOWNPOURS...WITH STREET FLOODING REPORTED IN
LANSING. EXPECT HEAVY RAIN AND LOCALIZED PONDING OF WATER TO
REMAIN A THREAT INTO THE EARLY EVENING...ESPECIALLY IN NW
INDIANA...THOUGH STORMS MAY INCREASE AS THE WARM FRONT TO THE
SOUTH AND DEEPER MOISTURE SPREAD NORTHWARD.
KMD
&&
.DISCUSSION...
221 PM CDT
SYNOPSIS...UNSETTLED WEATHER CONTINUES THROUGH TOMORROW WITH
SCATTERED THUNDERSTORMS EXPECTED. CONFIDENCE REMAINS LOW IN WHEN
AND WHERE THUNDERSTORMS WILL FORM. SUNDAY STILL LOOKS DRY BUT
MULTIPLE CHANCES FOR STORMS RETURN MONDAY THROUGH THE END OF THE
WEEK. ABOVE NORMAL TEMPERATURES ARE ALSO EXPECTED THROUGH THE PERIOD
AS WELL.
//NEAR TERM FORECAST//
THROUGH TONIGHT...
A LARGE RIDGE IS OVER THE EAST COAST WHILE A TROUGH IS OVER THE
PLAINS. THE TROUGH WILL WEAKEN AS IT APPROACHES OUR AREA AND PASS
OVERHEAD LATE SATURDAY NIGHT INTO SUNDAY MORNING. AT THE SURFACE THE
HIGH HAS PUSHED EAST WHILE A DEVELOPING LOW PRESSURE SYSTEM IS OVER
MINNESOTA. THE LOWS WARM FRONT LIES TO OUR SOUTH ACROSS SOUTHERN
IL...AND IT WILL LIFT NORTH THROUGH THE REGION THIS AFTERNOON.
HAVE VERY LOW CONFIDENCE IN EXACT TIMING AND LOCATION OF
THUNDERSTORMS THROUGH THIS EVENING. THERE IS NO CLEAR FORCING
MECHANISM BUT WITH AROUND 2000 J/KG OF CAPE AVAILABLE...STORMS ARE
CERTAINLY POSSIBLE. PWAT VALUES ARE AROUND 2 INCHES SO THE MAIN
CONCERN REMAINS HEAVY DOWNPOURS. THE STRONGEST STORMS MAY PRODUCE
WIND GUSTS TO 50 KT BUT NO SEVERE WEATHER IS EXPECTED AS WIND SHEAR
IS BASICALLY NIL.
FOR POPS USED A BLEND OF NEAR TERM GUIDANCE WHICH HAS BEEN DOING
REASONABLY WELL THIS MORNING. HOWEVER...KEPT A CHANCE OF STORMS
ACROSS THE REGION THIS AFTERNOON AND EVENING DUE TO THE SCATTERED
NATURE OF THE STORMS THAT ARE EXPECTED. A WASH OUT IS NOT
EXPECTED. THE BEST CHANCE FOR WIDESPREAD STORMS WILL BE OVERNIGHT
AS THE UPPER LEVEL TROUGH APPROACHES. IN FACT THE STORMS ASSOCIATED
WITH THE TROUGH STRETCH FROM MINNESOTA THROUGH ARKANSAS. MODELS
DIFFER IN HOW WELL THIS AREA OF PRECIP WILL HOLD TOGETHER SO LIMITED
POPS TO THE LIKELY CATEGORY.
LOWS WILL BE IN THE UPPER 60S TO LOWER 70S TONIGHT AND FOG IS
POSSIBLE. GIVEN THAT WE HAVE NOT SEEN MUCH RAIN TODAY...HAVE LIMITED
CONFIDENCE SO LEFT FOG OUT OF THE FORECAST FOR NOW.
SATURDAY AND SATURDAY NIGHT...
THE SURFACE LOW PASSES OVER LAKE MICHIGAN SATURDAY AFTERNOON WHILE
ITS COLD FRONT GETS DRAGGED THROUGH THE AREA SATURDAY
AFTERNOON/EVENING. SCATTERED STORMS ARE AGAIN POSSIBLE IN THE
MORNING IN THE WARM AND MOIST ENVIRONMENT WITH LINGERING 2 INCH PWAT
VALUES. STORMS WILL THEN FORM ALONG THE COLD FRONT SOUTH OF A GARY
IN TO PONTIAC IL LINE. STORMS ARE POSSIBLE NORTH AND WEST OF THIS
LINE...BUT CONFIDENCE IS SIGNIFICANTLY LOWER.
CAPE VALUES WILL BE AROUND 1000 J/KG TOMORROW WITH WEAK SHEAR ONCE
AGAIN. THEREFORE EXPECTING STORMS TO PRODUCE HEAVY DOWNPOURS AND THE
STRONGEST MAY BE CAPABLE OF GUSTY WINDS. SEVERE WEATHER IS NOT
EXPECTED.
TOMORROW LOOKS LIKE ANOTHER WARM AND STICKY DAY AHEAD OF THE COLD
FRONT. LOWS WILL BE IN THE 60S AND FOG IS POSSIBLE OVERNIGHT.
JEE
//EXTENDED FORECAST//
SUNDAY...
EXPECT A BRIEF LULL IN THE PRECIP CHANCES DURING MUCH OF THE DAY
SUNDAY AS THE FIRST COLD FRONT DEPARTS TO THE EAST AND ANOTHER LOW
TAKES SHAPE OVER THE NORTHERN PLAINS. IN BETWEEN THESE TWO
SYSTEMS...WEAK INDUCED SURFACE HIGH SHOULD RESULT IN QUIET WEATHER
LOCALLY...WITH THE H85 THERMAL RIDGE ADVECTING OVERHEARD THROUGHOUT
THE DAY. RETURN FLOW WILL HELP PUSH THE DEWPOINTS BACK UP TO AROUND
70 WITH AFTERNOON HIGH TEMPS EXPECTED TO BE IN THE MID 80S. STEEP
LOW/MID LEVEL LAPSE RATES WILL RESULT IN MODERATE INSTABILITY
DEVELOPING DURING THE AFTERNOON...BUT MODEST SBCIN IS PROGGED TO
STAY IN PLACE CAPPING ANY SURFACE BASED CONVECTION. IN ADDITION...
THE AREA SHOULD BE SQUARELY UNDER AREA OF MID LEVEL HEIGHT RISES
WHICH SHOULD HELP REINFORCE THE INVERSION...AND NO SIGNIFICANT
FORCING NOTED OVER THE AREA.
MONDAY...
TROUGHING CURRENTLY MOVING ONSHORE OVER THE PAC NORTHWEST TODAY WILL
MOVE ACROSS THE CENTRAL PLAINS THIS WEEKEND...THEN BEGIN TO LIFT
ACROSS THE UPPER MIDWEST EARLY NEXT WEEK. SURFACE LOW IS PROGGED TO
DEEPEN FROM THE NORTHERN PLAINS SUNDAY AS IT LIFTS TO NEAR HUDSON
BAY LATE ON MONDAY. THIS WILL DRAG A COLD FRONT ACROSS THE REGION ON
MONDAY. WITH THE LOW LIFTING AWAY FROM THE AREA...CONVERGENCE ALONG
THE FRONT IS PROGGED TO WEAKEN AS IT COMES ACROSS NORTHERN ILLINOIS
EARLY MONDAY WITH THE BETTER DYNAMICS STAYING TO OUR NORTH.
MEANWHILE...THE LOCAL AREA APPEARS TO LIE ON THE NORTHERN PERIPHERY
OF THE BETTER INSTABILITY TO OUR SOUTH. GFS SHOWS SOME HINTS THAT
PARTICULARLY NORTH CENTRAL ILLINOIS MAY BE SPLIT BY THE
PRECIP...ESPECIALLY CONSIDERING THE CAPPING EARLY IN THE DAY...BUT
WILL HOLD OFF ON FINE TUNING THIS DETAIL FOR NOW. IN ADDITION...THE
REGION DOES FALL WITHIN AN OVERLAPPED AREA OF FAVORABLE
SHEAR/INSTABILITY THAT COULD POTENTIALLY SUPPORT A SEVERE WEATHER
THREAT.
TUESDAY THROUGH FRIDAY...
FRONTAL BOUNDARY IS PROGGED TO STALL ACROSS/NEAR CENTRAL ILLINOIS
TUESDAY GRADUALLY LIFTING BACK NORTH ACROSS THE FORECAST AREA BY THE
END OF THE WORK WEEK AS A SERIES OF UPPER LEVEL DISTURBANCES MOVE
ACROSS THE REGION. THIS WILL RESULT IN PERIODIC CHANCES FOR SHOWERS
AND THUNDERSTORMS ACROSS THE AREA...THOUGH TIMING AND LOCATION
DETAILS WILL BE DIFFICULT TO PIN DOWN THIS FAR OUT GIVEN THE
PATTERN. THE ATMOSPHERE REMAINS QUITE SOUPY IN THE VICINITY OF THE
FRONT WHERE PWATS REMAIN AROUND 2 INCHES. THUS THE HEAVY RAIN AND
FLOODING THREAT WILL HAVE TO BE CLOSELY MONITORED THROUGH MUCH OF
THE UPCOMING WEEK.
DEUBELBEISS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* ISOLATED-SCATTERED SHRA/TSRA THIS AFTERNOON THRU EARLY EVENING.
* SOUTH WINDS WITH GUSTS 15-20 KT THIS AFTERNOON.
* ANOTHER PERIOD OF SHRA/TSRA LIKELY AFTER MIDNIGHT INTO SATURDAY
MORNING.
* SOUTHWEST WINDS GUSTING AROUND 20 KT SATURDAY.
RATZER
//DISCUSSION...UPDATED 20Z...
ISOLATED TSRA DEVELOPING FROM NORTHEAST OF DOWNTOWN CHICAGO SOUTH
INTO IKK AREA. THINK COVERAGE WILL REMAIN FAIRLY LOW...THOUGH HAVE
ADDED VCTS FOR THE NEXT FEW HOURS FOR CHICAGO TERMINALS AS THEY
WILL BE SPARSE BUT IN THE NEIGHBORHOOD SO TO SPEAK.
RATZER
PREVIOUS DISCUSSION FROM 18Z...
FAIRLY LOW CONFIDENCE CONVECTIVE FORECAST THIS PERIOD...WITH
TERMINALS WITHIN A BROAD AREA OF SOUTH WARM/MOIST ADVECTION
DOWNSTREAM OF AN UPPER TROUGH OVER THE CENTRAL PLAINS BUT WITH
OTHERWISE LITTLE ORGANIZED FOCUS FOR TSRA.
SATELLITE EVIDENCE OF WEAK MID-LEVEL DISTURBANCE OVER NORTHEAST
IL EARLY THIS AFTERNOON...WITH MORNING ELEVATED SHRA/TSRA DECAYING
OVER NORTH CENTRAL IL. DIURNAL TSRA WERE FORMING IN LOW LEVEL
INSTABILITY AXIS ALONG IL/IN BORDER REGION GENERALLY ALONG A DEC-
GIJ-MKG LINE...AND THIS LOOKS TO REMAIN THE FOCUS REGION FOR
HIGHEST COVERAGE TSRA THIS AFTERNOON. HIGH-RES GUIDANCE STILL
DEVELOPS SOME ISOLATED SHRA/TSRA INTO THE TERMINAL REGION IN
ASSOCIATION WITH AFOREMENTIONED MID-LEVEL DISTURBANCE AND NORTH
OF SURFACE WARM FRONT WHICH IS ACROSS DOWNSTATE IL AT THIS TIME...
THOUGH COVERAGE IS EXPECTED TO REMAIN LOW. A GREATER CHANCE OF
SHRA/TSRA APPEARS TO BE LATE TONIGHT AND EARLY SATURDAY AS THE
MAIN UPPER TROUGH APPROACHES. WEAK COLD FRONT APPROACHES FROM THE
WEST SATURDAY MIDDAY AND AFTERNOON...WITH THUNDERSTORMS EXPECTED
TO DEVELOP ALONG THE FRONT BY EARLY AFTERNOON. CURRENT SUITE OF
HIGH-RES GUIDANCE SUGGESTS TSRA POTENTIAL MAY BE GREATER JUST
EAST/SOUTH OF CHICAGO TERMINALS SATURDAY AFTERNOON. OUTSIDE OF ANY
PRECIP VIS REDUCTION EARLY SATURDAY...SOME MVFR HAZE POSSIBLE
OVERNIGHT IN MOIST WARM SECTOR AIR.
WINDS...GENERALLY SOUTH 10-12 KT WITH GUSTS TO 20 KT OR SO
POSSIBLE THIS AFTERNOON. WIND MAY BACK A BIT TO THE SOUTH-
SOUTHEAST LATE THIS AFTERNOON/EARLY EVENING AS SURFACE WARM
FRONT APPROACHES...BEFORE SHIFTING SOUTHWEST OVERNIGHT AND SUNDAY
AHEAD OF THE COLD FRONT. DEEPER MIXING SUNDAY SUGGESTS GUSTS AGAIN
IN THE 20 KT RANGE OR A LITTLE HIGHER DURING THE LATE MORNING AND
AFTERNOON.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM IN SHRA/TSRA BEING LOW IN COVERAGE IN IMMEDIATE TERMINAL
AREA THIS AFTERNOON...GREATER COVERAGE EAST/SOUTH OF CHICAGO.
* LOW IN TSRA TIMING/COVERAGE LATER TONIGHT/SATURDAY.
* MEDIUM-HIGH IN WIND TRENDS THROUGH PERIOD.
RATZER
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
* SATURDAY NIGHT THROUGH SUNDAY NIGHT...VFR. WX NIL.
* MONDAY...CHANCE OF TSRA.
* TUESDAY...VFR. WX NIL.
* WEDNESDAY THROUGH THURSDAY NIGHT...SLIGHT CHANCE OF TSRA
KREIN
&&
.MARINE...
221 PM CDT
MODERATE SOUTHERLY WINDS ARE IN PLACE TODAY AHEAD OF LOW PRESSURE
OVER THE NORTHERN PLAINS. SOUTH TO SOUTHWEST WINDS 20 TO 25 KT
WITH AN OCCASIONAL 30 KT GUSTS POSSIBLE WILL BE IN PLACE THROUGH
TOMORROW...THEN A COLD FRONT WILL START TO PUSH ACROSS THE LAKE
TURNING WINDS NORTHWESTERLY. HIGH PRESSURE WILL PROVIDE A BRIEF
LULL IN THE WINDS SUNDAY ALLOWING LAKE BREEZES TO DEVELOP...BUT
THEN SOUTHERLY WINDS RAMP BACK UP TO 25 TO 30 KT SUNDAY NIGHT INTO
MONDAY AHEAD OF ANOTHER LOW. THIS LOW IS PROGGED TO DEEPEN AS IT
LIFTS FROM THE NORTHERN PLAINS SUNDAY TO HUDSON BAY LATE MONDAY.
BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
303 PM CDT Fri Aug 29 2014
.SHORT TERM...(This evening through Saturday)
ISSUED AT 302 PM CDT FRI AUG 29 2014
19z/2pm surface analysis shows warm front extending from southern
Minnesota to southern Indiana, generally along the I-74 corridor
across central Illinois. Widely scattered showers and thunderstorms
have developed along the front and will continue to do so for the
balance of the afternoon. Meanwhile further upstream, a trough of
low pressure is evident across central Missouri where thunderstorms
are becoming more numerous. As this trough shifts northeastward,
storm chances will begin to increase across southwest Illinois early
this evening, then across the entire KILX CWA by mid to late
evening. May see a gradual decrease in areal coverage as daytime
instability is lost, so will keep PoPs in the 50-60 range tonight.
As has been the case for the past several days, any storms that
occur will be capable of frequent lightning and very high rainfall
rates of 1.5 to 2 inches per hour.
The trough axis will lift northeast of the area late tonight into
Saturday morning, with only scattered showers/storms lingering early
in the day. As a cold front currently across the Plains pushes
eastward and interacts with the very moist airmass in place across
the region, a renewed round of convection will be likely Saturday
afternoon/evening. Will carry high chance PoPs in the Illinois
River Valley and likely further east across the remainder of the CWA
accordingly.
&&
.LONG TERM...(Saturday night through Friday)
ISSUED AT 302 PM CDT FRI AUG 29 2014
In the wake of Saturdays precip, the boundary at the sfc slows and
becomes a bit more diffuse overall and models are starting to speed
up the clearing as the boundary slips to the southeast into the Ohio
River Valley. Though precip chances linger in southern and east
central Illinois on Saturday night, Sunday may be a break in the
widespread chances for rain. Next wave slowing in the 12z runs of
the ECMWF and the NAM...though the wave aloft is slowing, the GFS
qpf is slower to respond. Postponing the pops resulting in a dry
Sunday evening for the eastern half of the state with pops
increasing in the overnight hours along and west of Interstate 55,
with precip spreading and dominating much of the day on Monday.
Given the high PW values in the atmosphere, heavy rains will remain
a threat for the forecast pd. Delaying the onset of precip from
Sunday night into Monday also resulting in a prolonging into Monday
night. Question for the models beyond Monday night really revolving
around the boundary stalling in quasi zonal flow aloft not really
supporting any major progression of the sfc boundary and yet another
pd of being just on the edge of the unsettled weather with a signif
lack of 500mb height gradient over the southern half of the CONUS.
Whereas the GFS is pushing a series of MCSs on the edge of the weak
flow, the ECMWF is far more conservative...though both models are
tempering the amplification significantly over the latter half of
the work week. Thermal ridging in the south keeps above normal
temps over the region.
&&
.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
ISSUED AT 1250 PM CDT FRI AUG 29 2014
Widely scattered thunderstorms will continue to develop across
central Illinois over the next couple of hours as a warm front
lifts north of the area. Will carry VCTS at all terminals
accordingly. Meanwhile further upstream, regional radar mosaic is
showing a band of showers/thunder developing across western
Missouri into northern Arkansas. HRRR is showing this band lifting
N/NE this afternoon, eventually arriving in west-central Illinois
early this evening. Have therefore opted to carry predominant
light rain with VCTS for a 6-hour period at all sites this evening
into the overnight hours. Based on HRRR and observed trends, have
brought precip into KSPI after 02z, then further east to KCMI
after 05z. After this initial band lifts through the area, only
widely scattered showers will be noted Saturday morning.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BARNES
LONG TERM...HJS
AVIATION...BARNES
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
107 PM CDT FRI AUG 29 2014
.DISCUSSION...
326 AM CDT
THE MAIN FORECAST CONCERNS WILL CENTER AROUND CONVECTIVE CHANCES AND
TIMING...AS WELL AS TEMPERATURES TODAY...AND THROUGH THE HOLIDAY WEEKEND.
CURRENTLY...THE REMNANT MCV FROM YESTERDAY EVENINGS SHOWERS AND
STORMS CONTINUES TO SHIFT ACROSS MY SOUTHERN COUNTIES EARLY THIS
MORNING. HOWEVER...ONLY A FEW LIGHT SHOWERS/SPRINKLES REMAIN ACROSS
THIS AREA...WITH DRIER AND FAIRLY STABLE CONDITIONS IN PLACE TO THE EAST.
ANOTHER AREA OF CONVECTION IS ONGOING TO OUR WEST ACROSS IOWA AND
INTO SOUTHERN MN. THIS ACTIVITY IS OCCURRING WITHIN A REGION OF GOOD
LOWER LEVEL WARM AIR ADVECTION/ISENTROPIC ASCENT ON THE DOWNSTREAM
PERIPHERY OF A REMNANT MID/UPPER LEVEL TROUGH OVER THE PLAINS STATES.
DOWN STREAM UPPER RIDGING OVER THE GREAT LAKES REGION IS LEADING TO A
STEERING FLOW TO THE NORTHEAST. THEREFORE...MOST IF NOT ALL OF THIS
CONVECTIVE ACTIVITY WILL SHIFT INTO SOUTHERN WISCONSIN AND PERHAPS
FAR NORTHWESTERN ILLINOIS THIS MORNING. IN SPITE OF THIS...I HAVE
LEFT SLIGHT CHANCE POPS IN THIS MORNING AS IT IS POSSIBLE THAT SOME
ADDITIONAL CELLS COULD DEVELOP IN ASSOCIATION WITH AN EASTWARD MOVING
OUTFLOW BOUNDARY...AS EVIDENT OFF OF THE DMX RADAR MOVING TOWARDS
EASTERN IOWA. THIS ACTIVITY...IF IT OCCURS IN ANY OF NORTHERN
ILLINOIS EARLY THIS MORNING...WOULD LIKELY BE ISOLATED TO WIDELY
SCATTERED...WITH THE MAIN FOCUS REMAINING NORTH.
A SURFACE WARM FRONT IS EXPECTED TO LIFT NORTHWARD OVER THE AREA
INTO THIS AFTERNOON...WITH A WARMER AIRMASS EXPECTED IN ITS WAKE. IN
SPITE OF THIS...HOWEVER...HIGH TEMPERATURES ACROSS THE AREA WILL BE
TRICKY AS IT APPEARS THAT SOME SCATTERED THUNDERSTORMS COULD DEVELOP
ACROSS PORTIONS OF THE AREA THIS AFTERNOON...AND HAMPER THE MAGNITUDE
OF THE WARMTH ACROSS SOME AREAS. MODEST HEIGHT FALLS ALOFT ARE FORECAST
ACROSS NORTHERN ILLINOIS IN ASSOCIATION WITH THE AFOREMENTIONED UPPER
TROUGH SHIFTING EASTWARD OVER THE MID MISSOURI VALLEY THIS
AFTERNOON. IN SPITE OF THE FACT THAT THE BEST LARGE SCALE FORCING
FOR ASCENT WITH THIS DISTURBANCE SHOULD REMAIN WEST OF THE AREA THIS
AFTERNOON...THE EXPECTED INCREASE IN LOW-LEVEL THETA E IS EXPECTED
TO PRODUCE AN UNCAPPED ATMOSPHERE FEATURING MLCAPES OF AROUND 1500
J/KG BY THIS AFTERNOON. A MAJORITY OF THE GLOBAL MODELS...AS WELL AS
THE HIRES CONVECTIVE ALLOWING MODELS FIRE UP ACTIVITY WITHIN THIS
REGIME THIS AFTERNOON. IT APPEARS WE WILL HAVE TO WATCH MORNING
CLOUD COVER...HOWEVER...AS THIS COULD INHIBIT THE DEGREE OF
WARMING A BIT THROUGH THE MORNING...AND POSSIBLY LEAD TO WEAKER
INSTABILITY THAN WHAT THE MODELS ARE CURRENTLY ADVERTISING.
IF THE CONVECTION DOES DEVELOP AS EXPECTED...MARGINAL DEEP LAYER
SHEAR OF 25 TO 30 KT COULD ALLOW FOR A FEW STRONGER STORMS CAPABLE
OF SOME ISOLATED HIGH WIND GUSTS. SOME TORRENTIAL DOWNPOURS WOULD
ALSO BE A THREAT FROM THESE STORMS GIVEN THE JUICY AIRMASS FEATURING
PWATS UP AROUND 1.75 INCHES. HOWEVER...EXTREME RAINFALL AMOUNTS
APPEAR UNLIKELY GIVEN STORM MOTIONS SHOULD BE TO THE NORTHEAST
AROUND 30 KT. SO THE STORMS SHOULD NOT BE OVER A GIVEN AREA TOO
LONG. MUCH OF THIS ACTIVITY APPEARS TO BE HIGHLY DIURNAL IN
NATURE...SO A RAPID DOWNWARD TREND IS EXPECTED AFTER SUNSET THIS
EVENING.
ANOTHER ROUND OF THUNDERSTORMS APPEARS LIKELY ON
SATURDAY...ESPECIALLY DURING THE MORNING AS THE UPPER LEVEL
TROUGH...AND AN ASSOCIATED SURFACE LOW AND COLD FRONT SHIFTS
EASTWARD ACROSS ACROSS SOUTHERN WI AND NORTHERN IL. THIS ACTIVITY
COULD LINGER INTO SATURDAY EVENING ACROSS MY FAR SOUTHEASTERN
COUNTIES. HOWEVER...IT APPEARS THAT FOLLOWING THIS FRONTAL PASSAGE
WE WILL BE GREETED WITH A NICE DRY SUNDAY ACROSS THE AREA.
UNFORTUNATELY...LABOR DAY APPEARS THAT IT COULD BE ANOTHER ACTIVE
WEATHER DAY ACROSS THE REGION. ANOTHER POTENT UPPER LEVEL
DISTURBANCE AND SURFACE FRONT IS FORECAST TO SHIFT OVER THE AREA BY
MONDAY. WE WILL ALSO HAVE TO WATCH FOR THE THREAT OF SEVERE
THUNDERSTORMS ON MONDAY AND MONDAY NIGHT AS A 45 TO 50 KT MID LEVEL
JET IS PROGGED TO DEVELOP ACROSS THE AREA. THIS COULD RESULT IN DEEP
LAYER SHEAR STRONG ENOUGH TO PRODUCE MORE ORGANIZED STRONG TO SEVERE
CONVECTION. VERY HEAVY RAINFALL WOULD AGAIN BE A CONCERN WITH THIS
ACTIVITY...ESPECIALLY IF THE FRONTAL ZONE STALLS OUT OVER THE AREA
MONDAY NIGHT. AT THIS TIME...HOWEVER...UNCERTAINTY IS HIGH ON WHERE
THE SURFACE FRONT MAY STALL AND HENCE WHAT AREAS COULD BE FAVORED FOR
EXTENDED PERIODS OF VERY HEAVY RAINFALL.
THE ACTIVE WEATHER PATTERN COULD SHIFT SOUTH OF THE AREA FOR A DAY
OR TWO INTO MID TO LATE WEEK BEFORE MORE PERIODS OF CONVECTION ARE
POSSIBLE. OVERALL...IT APPEARS TEMPERATURES WILL REMAIN ON THE WARM
SIDE OF AVERAGE...WITH THE POTENTIAL FOR SOME VERY WARM AND HUMID DAYS
LATER NEXT WEEK.
KJB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* ISOLATED-SCATTERED SHRA/TSRA THIS AFTERNOON THRU EARLY EVENING.
* SOUTH WINDS WITH GUSTS 15-20 KT THIS AFTERNOON.
* ANOTHER PERIOD OF SHRA/TSRA LIKELY AFTER MIDNIGHT INTO SATURDAY
MORNING.
* SOUTHWEST WINDS GUSTING AROUND 20 KT SATURDAY.
RATZER
//DISCUSSION...UPDATED 18Z...
FAIRLY LOW CONFIDENCE CONVECTIVE FORECAST THIS PERIOD...WITH
TERMINALS WITHIN A BROAD AREA OF SOUTH WARM/MOIST ADVECTION
DOWNSTREAM OF AN UPPER TROUGH OVER THE CENTRAL PLAINS BUT WITH
OTHERWISE LITTLE ORGANIZED FOCUS FOR TSRA.
SATELLITE EVIDENCE OF WEAK MID-LEVEL DISTURBANCE OVER NORTHEAST
IL EARLY THIS AFTERNOON...WITH MORNING ELEVATED SHRA/TSRA DECAYING
OVER NORTH CENTRAL IL. DIURNAL TSRA WERE FORMING IN LOW LEVEL
INSTABILITY AXIS ALONG IL/IN BORDER REGION GENERALLY ALONG A DEC-
GIJ-MKG LINE...AND THIS LOOKS TO REMAIN THE FOCUS REGION FOR
HIGHEST COVERAGE TSRA THIS AFTERNOON. HIGH-RES GUIDANCE STILL
DEVELOPS SOME ISOLATED SHRA/TSRA INTO THE TERMINAL REGION IN
ASSOCIATION WITH AFOREMENTIONED MID-LEVEL DISTURBANCE AND NORTH
OF SURFACE WARM FRONT WHICH IS ACROSS DOWNSTATE IL AT THIS TIME...
THOUGH COVERAGE IS EXPECTED TO REMAIN LOW. A GREATER CHANCE OF
SHRA/TSRA APPEARS TO BE LATE TONIGHT AND EARLY SATURDAY AS THE
MAIN UPPER TROUGH APPROACHES. WEAK COLD FRONT APPROACHES FROM THE
WEST SATURDAY MIDDAY AND AFTERNOON...WITH THUNDERSTORMS EXPECTED
TO DEVELOP ALONG THE FRONT BY EARLY AFTERNOON. CURRENT SUITE OF
HIGH-RES GUIDANCE SUGGESTS TSRA POTENTIAL MAY BE GREATER JUST
EAST/SOUTH OF CHICAGO TERMINALS SATURDAY AFTERNOON. OUTSIDE OF ANY
PRECIP VIS REDUCTION EARLY SATURDAY...SOME MVFR HAZE POSSIBLE
OVERNIGHT IN MOIST WARM SECTOR AIR.
WINDS...GENERALLY SOUTH 10-12 KT WITH GUSTS TO 20 KT OR SO
POSSIBLE THIS AFTERNOON. WIND MAY BACK A BIT TO THE SOUTH-
SOUTHEAST LATE THIS AFTERNOON/EARLY EVENING AS SURFACE WARM
FRONT APPROACHES...BEFORE SHIFTING SOUTHWEST OVERNIGHT AND SUNDAY
AHEAD OF THE COLD FRONT. DEEPER MIXING SUNDAY SUGGESTS GUSTS AGAIN
IN THE 20 KT RANGE OR A LITTLE HIGHER DURING THE LATE MORNING AND
AFTERNOON.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM IN SHRA/TSRA BEING LOW IN COVERAGE IN IMMEDIATE TERMINAL
AREA THIS AFTERNOON...GREATER COVERAGE EAST/SOUTH OF CHICAGO.
* LOW IN TSRA TIMING/COVERAGE LATER TONIGHT/SATURDAY.
* MEDIUM-HIGH IN WIND TRENDS THROUGH PERIOD.
RATZER
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
* SATURDAY NIGHT THROUGH SUNDAY NIGHT...VFR. WX NIL.
* MONDAY...CHANCE OF TSRA.
* TUESDAY...VFR. WX NIL.
* WEDNESDAY THROUGH THURSDAY NIGHT...SLIGHT CHANCE OF TSRA
KREIN
&&
.MARINE...
315 AM CDT
HIGH PRESSURE OVER THE EASTERN GREAT LAKES WILL MOVE EAST OFF THE
NEW ENGLAND COAST FRIDAY EVENING...WHILE A TROUGH OF LOW PRESSURE
DEVELOPS ACROSS THE CENTRAL PLAINS AND UPPER MIDWEST. THIS WILL
SET UP A PERIOD OF SOUTHERLY WINDS AND AS THE TROUGH MOVES
EAST...THE GRADIENT OVER THE LAKE WILL STRENGTHEN AND WINDS SHOULD
INCREASE TO THE 20-25 KT RANGE. A DEEPENING LOW CENTER WITHIN THE
TROUGH WILL MOVE TO WISCONSIN SATURDAY AND ACROSS NORTHERN LAKE
MICHIGAN SATURDAY EVENING. AS THE LOW TRACKS TO THE NORTHEAST...AN
ASSOCIATED COLD FRONT WILL MOVE DOWN THE LAKE SATURDAY AFTERNOON
AND EVENING...QUICKLY SHIFTING WINDS TO NWLY FOLLOWING THE FROPA.
THE LATEST MODEL GUIDANCE SUGGESTS THAT THE FRONT WILL WASH OUT
LATE SATURDAY NIGHT BEFORE REACHING THE SOUTH END OF THE LAKE AND
WINDS THERE SHOULD NEVER TRULY SHIFT NWLY...BUT RATHER BECOMING
LIGHT AND VARIABLE LATE SATURDAY NIGHT THROUGH SUNDAY MORNING. A
DEEPER LOW IS EXPECTED TO DEVELOP OVER THE DAKOTAS AND LIFT
THROUGH WESTERN ONTARIO SUNDAY NIGHT AND MONDAY BRINGING A RETURN
TO BRISK SOUTH TO SOUTHWEST WINDS TO THE LAKE FOR MONDAY AND
TUESDAY.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1250 PM CDT Fri Aug 29 2014
.UPDATE...
ISSUED AT 948 AM CDT FRI AUG 29 2014
Made a quick update to the forecast to raise PoPs from Lincoln
northward to Henry due to current radar trends. A cluster of
thunderstorms with high rainfall rates of 1.5 to 2 inches per hour
is lifting northward into Tazewell and western McLean counties at
this time and will continue northward across Woodford and Marshall
counties over the next couple of hours. Once this cluster
weakens/exits the KILX CWA toward midday, additional showers/storms
will develop along outflow boundaries as well as the synoptic warm
front as it pushes northward later today. Have gone with low
chance PoPs across the board this afternoon, with highs climbing
well into the 80s.
&&
.SHORT TERM...(Today and tonight)
ISSUED AT 337 AM CDT FRI AUG 29 2014
Frontal boundary from NW Missouri through southern Illinois into
Kentucky will push northward today as southwesterly flow increases
ahead of a trough currently over the central plains. For this
afternoon convection will be primarily driven by surface heating and
not well organized, therefore have ramped up pops through early
afternoon and trended them downward in early evening in eastern IL.
In the early evening, the upper level trough and weak surface cold
front associated with the plains system begin to move into western
IL. This will bring a good chance of showers and thunderstorms
pushing across central and southeast IL overnight. Temperatures for
today will be similar to Thursdays...generally mid to upper 80s with
dew points in the low 70s resulting in heat index values in the low
to mid 90s.
&&
.LONG TERM...(Saturday through Thursday)
ISSUED AT 337 AM CDT FRI AUG 29 2014
Cold front accompanying current deep Plains upper trough will be
losing some of its punch as it comes into the mid-Mississippi
Valley, but will still be potent enough for showers and
thunderstorms to be likely on Saturday over our area. Some heavier
rains will be possible with the stronger storms, primarily over the
southeast CWA where precipitable water values will be around 1.8
inches Saturday afternoon, about 2 standard deviations above normal
for the end of August. The precipitation threat will continue
Saturday night and Sunday over the southeast CWA as moisture
continues to surge into the Ohio Valley. However, the northwest half
of the forecast area should be dry during this period.
West-east upper high to dominate the lower CONUS into mid week, as a
broad trough tracks across the northern states. Showers and storms
ahead of the surface front should begin spreading in northwest of
the I-55 corridor after midnight Sunday night. Most of the models
try to form some sort of dual MCS`s, one tracking east across
Wisconsin and the other southwest through Missouri, with some
potential for lesser amounts of rain Monday morning. However,
redevelopment is expected by afternoon as the front starts to hang
up in the upper flow, so have likely PoP`s over most of the CWA for
Monday. With the frontal boundary in the vicinity, the 00Z models
are trending more toward additional MCS activity tracking over our
forecast area Monday night. Have increased the PoP`s some,
especially across the north which had been dry Monday night. The
front should start to be dragged a bit further south on Tuesday as a
surface wave moves along it, but have kept PoP`s in the 30-40% range
into Tuesday night before the focus shifts more into the Ohio Valley.
Mid to late week, the upper high begins to ridge again across the
Mississippi Valley. 850 mb temperatures of 20-22C should allow for
highs to return to the 90s late next week.
&&
.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
ISSUED AT 1250 PM CDT FRI AUG 29 2014
Widely scattered thunderstorms will continue to develop across
central Illinois over the next couple of hours as a warm front
lifts north of the area. Will carry VCTS at all terminals
accordingly. Meanwhile further upstream, regional radar mosaic is
showing a band of showers/thunder developing across western
Missouri into northern Arkansas. HRRR is showing this band lifting
N/NE this afternoon, eventually arriving in west-central Illinois
early this evening. Have therefore opted to carry predominant
light rain with VCTS for a 6-hour period at all sites this evening
into the overnight hours. Based on HRRR and observed trends, have
brought precip into KSPI after 02z, then further east to KCMI
after 05z. After this initial band lifts through the area, only
widely scattered showers will be noted Saturday morning.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BARNES
SHORT TERM...ONTON
LONG TERM...GEELHART
AVIATION...BARNES
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
112 AM CDT FRI AUG 29 2014
.DISCUSSION...
714 PM CDT
PAIR OF MCVS NOTED ON RADAR IMAGERY CONTINUE TO MOVE EASTWARD
DRIVING SLOWLY DECAYING CONVECTIVE COMPLEX EASTWARD INTO OUR CWA
EARLY THIS EVENING DESPITE THE MUCH MORE STABLE AND SOMEWHAT DRIER
AIR MASS OVER THE REGION. HAVE ALREADY UPDATED PRECIP TRENDS A
COUPLE TIME TO ACCOUNT FOR THE RAIN THIS EVENING. ANTICIPATE
CONTINUED WEAKENING TREND...PARTICULARLY FROM THE NORTH...IN THIS
AREA OF LEFT OVER RAIN AND EVEN SOME LINGERING THUNDER. THE THREAT
OF THUNDER WITH THE NORTHERN MCV TRACKING CLOSE TO I-88 LOOKS TO END
VERY SOON...WHILE THE CONVECTION WITH THE SOUTHERN MOST MCV LIES
CLOSE ENOUGH TO MORE UNSTABLE AIR TO POTENTIALLY MAINTAIN
THUNDERSTORMS ACROSS THE SOUTHERN TIER OF OUR CWA THE NEXT FEW
HOURS. IN THE WAKE OF THESE MCVS...WHICH REALLY HAVENT BEEN HANDLED
WELL BY NUMERICAL GUIDANCE...SHOULD SEE A PERIOD OF DRY CONDITIONS
HOWEVER MODELS DO BREAK OUT ADDITIONAL CONVECTION OVERNIGHT WHICH
ISN`T THAT UNREASONABLE GIVEN THE NORTHWARD ADVANCING WARM FRONT.
IZZI
//PREV DISCUSSION...
230 PM CDT
VISIBLE IMAGERY THIS AFTERNOON SHOWS A MID/UPR LEVEL CLOUD DECK
LIFTING NORTHEAST ACROSS NORTHERN IL. REMNANTS FROM A MORNING
COMPLEX OF THUNDERSTORMS RESIDES OVER IOWA...WITH SOME CONVECTIVE
LOOK TO THE CLOUDS LINGERING INTO THIS AFTN. SFC TEMPS ACROSS THE
FORECAST AREA HAVE BEEN ABLE TO WARM INTO THE MID/UPR 70S. A FEW
POINTS SOUTH OF PONTIAC TO KANKAKEE HAVE PUSHED TO ARND 80 DEG...BUT
WITH THE LIGHT EASTERLY FLOW AT THE SFC SOME WEAK SUBSIDENCE HAS
BEEN NOTED WITH DEW POINTS BEING PUSHED INTO THE LOW 50S ALONG THE
LAKESHORE AND MID/UPR 50S INLAND.
THE MAIN CHALLENGE FOR THIS EVENING WILL FOCUS ON CONVECTIVE
CHANCES/COVERAGE...WHICH WILL CONTINUE THROUGH DAYBREAK FRI.
GUIDANCE HAS CONTINUED TO BACK OFF ON THE ARRIVAL OF PRECIP INTO THE
FORECAST AREA...WHICH SEEMS TO LINE UP RELATIVELY WELL WITH THE
CURRENT TRENDS. THE FRONTAL BOUNDARY WILL SLOWLY LIFT NORTH THIS
EVENING...BUT NOT EXPECTING MUCH IN THE WAY OF PRECIP UNTIL PERHAPS
AFT 04Z WITH A GRADUAL UPGLIDE OF PARCELS ALLOWS FOR MOISTENING.
SOME ELEVATED CONVECTION COULD BEGIN TO DEVELOP...ALTHOUGH NOT
EXPECTING MUCH COVERAGE OVERNIGHT. THE FOCUS FOR SLIGHTLY BETTER
PRECIP COVERAGE WILL REMAIN ALONG THE NORTHERN ROW OF COUNTIES IN
NORTHERN IL...HOWEVER CLOSER TO DAYBREAK FRI IT APPEARS SOME
PRECIP/CONVECTION COULD SAG SOUTHEAST AND CLIP NORTHEAST
IL/NORTHWEST IN BEFORE DISSIPATING.
WITH INCREASING CLOUD COVER TONIGHT...IT SHUD LIMIT HOW COOL TEMPS
BECOME. SO HAVE MADE ONLY MINOR ADJUSTMENTS TO THE TEMPS WITH
GENERALLY MID/UPR 60S FOR LOWS.
BEACHLER
FRIDAY AND FRIDAY NIGHT...
CLOSED UPPER LOW CURRENTLY NEAR THE COLORADO FRONT RANGE WILL SLOWLY
TRAVERSE EAST TOWARDS THE MID-MISSOURI VALLEY FRIDAY BECOMING AN
OPEN WAVE. AT THE SURFACE...BROAD AND WEAK SURFACE LOW WILL LIFT
INTO THE UPPER MIDWEST WHILE SOUTHWEST FLOW RAMPS UP THROUGH THE
COLUMN AS THE WARM FRONT LIFTS INTO THE CENTRAL GREAT LAKES. HEAT
AND HUMIDITY WILL MAKE A RETURN AS THIS OCCURS. H85 TEMPS WARMING TO
AROUND 18C WILL HELP SUPPORT MID/UPPER 80S DURING THE DAY
FRIDAY...AND SURFACE DEWPOINTS ARE PROGGED TO PUSH BACK INTO THE LOW
POSSIBLY MID 70S. THIS WILL RESULT IN MODERATE INSTABILITY
DEVELOPING DURING THE DAY...AND ONLY WEAKLY CAPPED DURING THE
AFTERNOON AS BROAD HEIGHT FALLS ASSOCIATED WITH THE UPPER WAVE START
TO OVERSPREAD THE AREA. THERE DOESNT SEEM TO BE MUCH FOCUS IN THE
LOWER LEVELS SO WOULD EXPECT ONLY SCATTERED THUNDERSTORM DEVELOPMENT
ACROSS THE REGION FRIDAY AFTERNOON/EVENING. UPPER WAVE BEGINS TO
MOVE INTO THE UPPER MIDWEST TOMORROW NIGHT AND BROAD WARM ADVECTION
OUT AHEAD DURING THE EVENING AND OVERNIGHT HOURS WILL HELP SUSTAIN
SOME CONVECTION LATE BUT WOULD EXPECT SOME NOCTURNAL DOWNTICK IN
ACTIVITY OVERNIGHT WITH THE LOW LEVEL JET FOCUSED WELL TO OUR NORTH.
GFS/NAM SEEM TO BE OVERDOING POPS MUCH OF THE DAY AND NIGHT
FRIDAY...AND OPTED TO LEAN CLOSER TO ECMWF THESE PERIODS.
THIS WEEKEND...
COLD FRONT WILL SWEEP ACROSS THE FORECAST AREA STARTING VERY EARLY
ON SATURDAY. WHILE NOT A FAVORABLE DIURNAL TIME...WE SHOULD STILL
HAVE SOME VERY MODEST INSTABILITY IN PLACE THAT WILL SUPPORT SOME
EARLY DAY THUNDERSTORMS ALONG THE FRONTAL BOUNDARY...WHICH WOULD BE
ABLE TO EXPAND IN COVERAGE AS THE DAY PROGRESSES AND THE BOUNDARY
LAYER WARMS. IN ADDITION...GUIDANCE SUGGESTS A SECOND SHORTWAVE
WILL WRAP INTO THE AREA THAT WILL PROVIDE ADDITIONAL BROAD SCALE
ASCENT. THE ECMWF IS ABOUT SIX HOURS SLOWER WITH THIS FEATURE
COMPARED TO THE NAM/GFS...WITH THE GEM A COMPROMISE...SO THERE
REMAINS SOME UNCERTAINTY IN TIMING. HIGH PRESSURE WILL BUILD IN
BEHIND THE FRONT SATURDAY NIGHT INTO SUNDAY AND WILL PROVIDE A
BRIEF RESPITE FROM THE ACTIVE WEATHER. THE ATMOSPHERE LOOKS TO
QUICKLY RELOAD HOWEVER WITH THERMAL RIDGE ONCE AGAIN STARTING TO
TILT BACK OVER THE AREA WITH H85 TEMPS AROUND 20C BY LATER IN THE
DAY SUNDAY.
NEXT WEEK...
AN ACTIVE PATTERN LOOKS TO PERSIST THROUGH AT LEAST THE MIDDLE OF
NEXT WEEK WITH A SERIES OF WAVES PUSHING ACROSS THE REGION BRINGING
CONTINUED PERIODIC CHANCES FOR SHOWERS AND THUNDERSTORMS. ANOTHER
COLD FRONT WILL PUSH ACROSS THE AREA LATER ON MONDAY WITH THE
FRONTAL BOUNDARY STALLING JUST TO OUR SOUTH. THEREAFTER...THERE IS
CONSIDERABLE UNCERTAINTY ON HOW FAR NORTH THE BOUNDARY MAY LIFT
WITH THE BEST PRECIP CHANCES FOCUSED IN THE VICINITY OF THE
FRONT AS A SERIES OF UPPER LEVEL DISTURBANCES PUSH ACROSS THE
AREA. PWATS REMAIN JUICY ALONG THE FRONT...AROUND TWO INCHES...AND
GUIDANCE SUGGESTS THAT THERE COULD BE SEVERAL CONVECTIVE COMPLEXES
NEXT WEEK WITH A CONCERN FOR HEAVY RAIN AND FLOODING SHOULD THIS
PAN OUT.
DEUBELBEISS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* ISOLATED SHRA/TSRA LATE TONIGHT INTO EARLY FRIDAY MORNING.
* SCATTERED TSRA FRIDAY AFTERNOON/EARLY EVENING.
* SOUTH WIND WITH GUSTS DEVELOPING TO 20KT LATE MORNING FRIDAY.
KREIN
//DISCUSSION...UPDATED 06Z...
FORECAST CONCERNS WILL FOCUS ON SHRA/TSRA POTENTIAL THROUGH THE
PERIOD AS WELL AS GUSTY SOUTH WINDS DEVELOPING LATE FRIDAY MORNING
AND PERSISTING INTO EARLY FRIDAY EVENING.
FOR THE REMAINDER OF THE OVERNIGHT HOURS...THE REGION WILL REMAIN
UNDER SELY FLOW...NORTH OF A WARM FRONT CURRENTLY OVER CNTRL MO TO
SRN IL. SOME REMNANT SHOWERS FROM EARLIER CONVECTIVE ACTIVITY ARE
STILL SEEN ON THE LATEST RADAR IMAGERY...BUT THIS ACTIVITY IS
DIMINISHING WITH TIME FOR MUCH OF THE REGION. THE EXCEPTION IS A
SMALL AREA OF RAIN WHICH IS MORE PERSISTENT OVER ECNTRL IL. WITH
MID LEVEL FLOW MORE SOUTHWESTERLY...THERE HAS BEEN A MORE
PERSISTENT FETCH OF LIGHT PCPN INTO NWRN IL...SO KGYY COULD LIKELY
SEE SOME LIGHT RAIN THROUGH THE NIGHT THOUGH NO ADDITION THUNDER
IS ANTICIPATED WITH THIS PCPN. WITH A VERY MOIST AIRMASS IN PLACE
FROM RECENT PCPN ALONG WITH LIGHT WINDS...THERE WILL BE THE
POTENTIAL FOR SOME PATCHY BR WITH KDPA/KRFD BEING THE MORE LIKELY
TAF SITES TO SEE VIS DROP AT LEAST INTO MVFR LEVELS. EXPECT THAT
ORD/MDW SHOULD REMAIN VFR AS WINDS WILL REMAIN A LITTLE STRONGER
AND TEMP/DEWPOINT SPREADS A LITTLE HIGHER.
THE WARM FRONT WILL SLOWLY LIFT NWD THROUGH THE NIGHT AND PUSH
NORTH OF THE TERMINALS BY LATE FRIDAY MORNING. AT THIS
POINT...WINDS WILL SHIFT TO MORE SOUTHERLY. SOME BREAKS IN THE
CLOUD COVER SHOULD ALLOW FOR DEEPER LAYER MIXING...TAPPING
STRONGER WINDS ALOFT AND EXPECT THAT WINDS WILL BEGIN TO GUST TO
20KT FOLLOWING THE WARM FROPA.
INSTABILITY WILL INCREASES VERY QUICKLY AS THE WARM FRONT PASSES
TO THE NORTH AND WARM SECTOR AIR OVERSPREADS THE REGION BRINGING
INCREASING TEMPERATURES AND DEWPOINTS. MID LEVEL IMPULSES SHOULD
TRACK ACROSS THE AREA FRIDAY AFTERNOON AND EVENING IN UPPER LEVEL
SWLY FLOW AS THE UPPER RIDGE PUSHES TO THE EAST AND A LARGER SCALE
UPPER TROUGH MOVES ACROSS THE CENTRAL PLAINS. THESE IMPULSES WILL
BE THE TRIGGERING MECHANISM FOR ADDITIONAL SHRA/TSRA...BUT IN THE
ABSENCE OF ANY SFC FORCING...ACTIVITY WILL GENERALLY BE SCATTERED
AND DIFFICULT TO TIME AT THE TERMINALS. SO...WILL MAINTAIN THE
GOING PROB30 GROUP FOR TSRA WITH THE MOST FAVORABLE TIMING DURG
THE AFTERNOON HOURS. HOWEVER...WITH SCATTERED COVERAGE...ANY OF
THE TERMINALS COULD SEE SOME SHRA/TSRA A LITTLE EARLIER OR A
LITTLE LATER THAN THE GOING PROB30 TIMING.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* LOW CONFIDENCE IN THUNDER CHANCES/COVERAGE AND SPECIFIC TIMING
FRIDAY AFTERNOON.
* HIGH CONFIDENCE IN WIND TRENDS THROUGH THE PERIOD.
* MEDIUM CONFIDENCE THAT ORD/MDW WILL REMAIN VFR THROUGH THE
REMAINDER OF THE NIGHT AND INTO EARLY FRIDAY MORNING.
KREIN
//OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z...
* SATURDAY...TSRA LIKELY.
* SUNDAY...SLIGHT CHANCE OF TSRA.
* MONDAY AND TUESDAY...CHANCE OF TSRA.
* WEDNESDAY AND THURSDAY...SLIGHT CHANCE OF TSRA
KMD
&&
.MARINE...
123 PM CDT
SURFACE HIGH PRESSURE OVER THE GREAT LAKES REGION THIS AFTERNOON
WILL DRIFT TO THE EAST TONIGHT IN THE WAKE OF A DEPARTING UPPER
TROUGH OVER NEW ENGLAND/QUEBEC...AND AHEAD OF ANOTHER SURFACE TROUGH
AND WEAK COLD FRONT STRETCHING FROM FAR NORTHWEST ONTARIO TO THE
CENTRAL PLAINS. WINDS ON LAKE MICHIGAN WILL SHIFT TO THE SOUTHEAST
AND EVENTUALLY SOUTH HEADING INTO FRIDAY...AS AN AREA OF SURFACE LOW
PRESSURE DEVELOPS ACROSS THE PLAINS AND LIFTS ACROSS THE UPPER
MISSISSIPPI RIVER VALLEY. TIGHTENING OF THE PRESSURE GRADIENT
SOUTHEAST OF THE LOW TRACK WILL RESULT IN S-SE WINDS INCREASING INTO
THE 15-25 KT RANGE TONIGHT AND FRIDAY...GRADUALLY WEAKENING SATURDAY
AS THE LOW MOVES OFF TO THE NORTHEAST AND A WEAK COLD FRONT TRAILS
ACROSS THE LAKE FOLLOWED BY WEAK HIGH PRESSURE.
THIS COLD FRONT APPEARS TO DISSIPATE OR STALL ACROSS FAR SOUTHERN
LAKE MICHIGAN OR NORTHERN IL/IND LATE SATURDAY NIGHT OR EARLY SUNDAY
BEFORE DEVELOPING BACK TO THE NORTH AS A WARM FRONT SUNDAY NIGHT AS
ANOTHER AREA OF LOW PRESSURE DEVELOPS OVER THE PLAINS AND LIFTS
NORTHEAST INTO THE WESTERN/NORTHERN LAKES LATE SUNDAY NIGHT INTO
MONDAY. AGAIN...A TIGHTENING OF THE PRESSURE GRADIENT ALONG THE
SOUTHEAST PERIPHERY OF THE LOW TRACK IS EXPECTED WITH WINDS AGAIN
BECOMING SOUTHERLY INTO THE 15-25 KT RANGE ON MONDAY. ANOTHER
TRAILING COLD FRONT WILL PASS ACROSS THE LAKE MONDAY NIGHT...WITH
WEAK HIGH PRESSURE AND LIGHTER WINDS DEVELOPING TUESDAY.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1159 PM CDT Thu Aug 28 2014
.SHORT TERM...(This evening through Friday)
ISSUED AT 255 PM CDT THU AUG 28 2014
18z/1pm surface map shows warm front extending from northern
Missouri into western Kentucky. Aloft...vigorous upper-level low is
evident on water vapor imagery over eastern Colorado/western Kansas.
Large cluster of showers/storms associated with the low developed
along the front across Iowa last night and has since weakened as it
lifted northeastward into drier air over the Upper Midwest/Great
Lakes. Convection is still ongoing along outflow boundary from
eastern Iowa into northern Missouri: however, most of this will
remain W/NW of the KILX CWA late this afternoon into the early
evening. Meanwhile, scattered convection is firing further south
along the front across western Kentucky and this is expected to
develop further north into central Illinois over the next couple of
hours. HRRR has had a good handle on the convection and have
followed its solution closely for the immediate short-term. Have
therefore gone with scattered showers/thunder across all but the far
NE CWA around Champaign and Danville this afternoon into the
evening. Think convection will be diurnally driven and will
dissipate shortly after sunset.
As upper low slowly approaches from the west, corresponding
downstream ridging will help push the warm front northward tonight
into Friday. With strongest upper support remaining west of
Illinois through the day, think convection will once again only be
scattered in nature and primarily occur during peak heating. Have
therefore gone with a mostly dry forecast during the morning,
followed by chance PoPs during the afternoon. Best rain chances
will be focused closer to the frontal boundary across the northern
two-thirds of the CWA. High temperatures on Friday will be held
down a bit by clouds/precip, but will still rise well into the 80s,
with locations along/south of I-70 perhaps hitting the 90-degree
mark.
&&
.LONG TERM...(Friday night through Thursday)
ISSUED AT 255 PM CDT THU AUG 28 2014
Upper wave currently over the Rockies expected to slowly move out
and bring rain chances to the area, particularly Friday night and
Saturday as the upper trof moves through the Midwest. Keeping the
precip around on Saturday may result in slightly cooler temperatures
by the afternoon. Once again, the cold front associated with the
upper trof moves across the region, losing its distinct baroclinic
zone and becoming more diffuse as it slows considerably just to the
southeast near the Ohio River Valley. The remaining boundary will
keep pops around for the areas in the southeastern portions of the
state through the remains of the weekend until another larger trof
moves across the country bringing more widespread rain and thunder
for Sunday night into Monday. Signif differences between the ECMWF
and the GFS with the GFS being weaker with the boundary and leaving
a more stationary focus for prolonged showers...whereas the ECMWF is
more progressive and dries out the region on Tuesday. At this
point, the ECMWF builds a weak upper ridge into the Midwest and the
GFS stays more active.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
ISSUED AT 1156 PM CDT THU AUG 28 2014
The new 06Z TAF valid time is expected to be much like the past
couple. Predominantly VFR/quiet weather conditions are expected.
However, scattered showers/storms are possible. Initially the main
precipitation threat will be diurnally driven on Friday, but
chances will also be increasing Friday evening with the approach
of a cold front. As such, it is difficult to pinpoint
precipitation until it is closer to arrival time. So, have limited
most mention to VCTS. Storms, if they impact a terminal, may
briefly reduce cigs/vsbys to MVFR or lower.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BARNES
LONG TERM...HJS
AVIATION...BAK
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
729 PM EDT SAT AUG 30 2014
.SYNOPSIS...
ISSUED AT 729 PM EDT SAT AUG 30 2014
SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE TO MOVE ACROSS
NORTHWEST PARTS OF THE AREA THIS EVENING AS LOW PRESSURE TRACKS
INTO THE NORTHERN GREAT LAKES. DRIER AIR WILL BRIEFLY WORK INTO
THE AREA ON SUNDAY BEFORE A COLD FRONT BRINGS RENEWED CHANCES FOR
SHOWERS AND THUNDERSTORMS ON MONDAY. LOWS WILL BE NEAR 70 WITH
HIGHS ON SUNDAY AND MONDAY IN THE LOW TO MID 80S.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 335 PM EDT SAT AUG 30 2014
CONVECTIVE DEVELOPMENT HAS TRIGGERED WHERE THE CLOUDS CLEARED
EARLIER TODAY...MAINLY OVER CENTRAL ILLINOIS TO LOWER LAKE
MICHIGAN AND INTO NORTHERN MICHIGAN. BEST SYNOPTIC SCALE FORCING
ASSOCIATED WITH THE LOW/TROF IN WISCONSIN. FLOW REGIME IS SUCH
THAT THE CONVECTION HAS DEVELOPED IN A STRETCHING DEFORMATION
AXIS. HRRR AND LOCAL WRF SHOW THE SFC BASED FRONTOGENESIS IN THIS
AXIS...
LAPSE RATES AND WIND PROFILES SUPPORT THE POTENTIAL FOR CONVECTIVE
LINES AND INDIVIDUAL LINE SEGMENTS. ISOLATED THREAT FOR SEVERE WIND
GUSTS. DO NOT EXPECT TO SEE SUSTAINED CONVECTIVE DEVELOPMENT AS THE
BOUNDARY LAYER FORCING DOES NOT PERSIST MUCH PAST 04Z.
LOW LEVEL JET KICKS IN OVERNIGHT AND THIS SHOULD BE ENOUGH TO
SUSTAIN MORE ORGANIZED SHRA/TSRA ACROSS THE SOUTHEASTERN HALF OF THE
FORECAST AREA. WHILE THERE IS DISCREPANCY IN TIMING AND INTENSITY
BETWEEN THE MODELS...THE BOUNDARY LAYER CAPE AND WIND PROFILES ARE
VERY SIMILAR AND DO SUPPORT PERSISTENT/LINGERING SHOWERS THROUGH
SUNDAY MORNING. WITH ABUNDANT MOISTURE TAP AND A LONG FETCH OF
ISENTROPIC ASSENT...SOME OF THE SHOWERS COULD PRODUCE MODERATE TO
LOCALLY HEAVY RAINFALL.
AS THE LOW LEVEL JET DECREASES AND THE TROF/DEFORMATION AXIS SHIFTS
EASTWARD...EXPECT IMPROVING CONDITIONS DURING THE DAY SUNDAY AHEAD
OF ANOTHER MORE ROBUST SYNOPTIC SYSTEM APPROACHING THE AREA FOR
MONDAY.
&&
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 335 PM EDT SAT AUG 30 2014
MAIN FOCUS OF LONG TERM IS ON PRECIP/SEVERE WEATHER CHANCES MONDAY
INTO MONDAY NIGHT. WELL DEFINED MID/UPPER LEVEL TROUGH CURRENTLY
DIGGING INTO THE PACIFIC NORTHWEST WILL SWING THROUGH THE GREAT
LAKES LATE MONDAY. TROUGH WILL BE LIFTING AS IT MOVES THROUGH THE
REGION BUT STRONG PUSH OF HEIGHT FALLS AND CVA WILL SUPPORT A DECENT
SURFACE CYCLONE AND ATTENDANT COLD FRONT. PRECIP CHANCES WILL BE
FURTHER AIDED BY GOOD RIGHT ENTRANCE JET DYNAMICS OVER THE SOUTHERN
GREAT LAKES. DEEP AND STRONG SOUTHWEST FLOW AHEAD OF THE TROUGH WILL
EASILY ADVECT HIGH THETA-E AIRMASS BACK INTO OUR AREA ON MONDAY.
AFTERNOON SBCAPE VALUES EXPECTED TO REACH THE 2-3 KJ/KG RANGE AS
HIGH TEMPS CLIMB INTO THE MID...OR PERHAPS UPPER...80S WITH SURFACE
DEWPOINTS IN THE LOW 70S. VERY DYNAMIC WAVE WILL LIKELY SUPPORT
NUMEROUS SHOWERS AND THUNDERSTORMS BUT TIMING WILL BE CRITICAL TO
SEVERE WEATHER CHANCES. LATEST 12Z NWP SUITE KEEPS SURFACE BOUNDARY
WEST OF OUR CWA UNTIL TUESDAY MORNING. ISO/SCT CONVECTION MAY
DEVELOP IN THE WARM SECTOR MONDAY AFTERNOON ALONG WEAK PREFRONTAL
TROUGH AS SUGGESTED BY THE LATEST NAM12 BUT EXPECT BULK OF THE
ACTIVITY WILL BE TIED TO THE ACTUAL COLD FRONT LATE MONDAY NIGHT.
BETTER WIND PROFILES...WITH 0-6KM SHEAR OF 30+ KNOTS...WILL ALSO BE
TIED CLOSER TO THE FRONT. DESPITE MORE THAN ADEQUATE
SHEAR...MIDLEVEL LAPSE RATES OF 6-7 C/KM ARE ONLY WEAKLY SUPPORTIVE
OF A NOCTURNAL SEVERE WEATHER THREAT. FORECAST SOUNDINGS INDICATE
ONLY AROUND 1000 J/KG OF ELEVATED INSTABILITY MONDAY NIGHT....PLENTY
FOR WIDESPREAD THUNDERSTORMS BUT SEVERE POTENTIAL IS LESS CLEAR.
THERE WILL BE A THREAT FOR SEVERE WINDS...AND POTENTIAL
ROTATION...WITH ANY SUBSTANTIVE UPDRAFTS THAT MANAGE TO DEVELOP BUT
LATE ARRIVAL OF FRONT MAY LIMIT CHANCES FOR A WIDESPREAD SEVERE
WEATHER EVENT. PUSHED BACK TIMING OF POPS BUT ALSO INCREASED THEM A
BIT BASED ON LATEST MODEL SOLUTIONS. COULD ALSO BE A THREAT FOR
STRONGER STORMS IN OUR FAR SOUTHEAST COUNTIES LATE TUESDAY MORNING
IF SURFACE BOUNDARY IS SLOW ENOUGH TO EXIT THE CWA.
QUIET WEATHER EXPECTED MIDWEEK BEFORE ANOTHER TROUGH APPROACHES NEXT
WEEKEND. SCT CONVECTION MAY BE POSSIBLE THURSDAY INTO FRIDAY AS WARM
FRONT LIFTS NORTH ONCE AGAIN BUT BEST CHANCES LOOK TO HOLD OFF UNTIL
THE WEEKEND. AFTER A BRIEF BREAK TUES AND WED...HEAT AND HUMIDITY
WILL RETURN FOR THE END OF THE WEEK AS ACTIVE WEATHER PATTERN
CONTINUES.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 729 PM EDT SAT AUG 30 2014
VFR CONDS THIS EVENING WILL GIVE WAY TO A PD OF MVFR/IFR CONDS LT
TONIGHT AS WK SFC TROUGH STALL ACRS THE AREA. FORCING ALG TRAILING
BNDRY ASSOCD/W PARENT SW SHIFTING EWD THROUGH NRN WI HAS SO FAR BEEN
GENERALLY POOR W/FRACTURED...POORLY DVLPD CONVECTIVE LINE EXTENDING
FM ERN IL NEWD THROUGH NW IN/SRN MI. DOUBT THIS WILL IMPROVE
OVERNIGHT AS NR TERM HIGHRES GUIDANCE WEAKENS VEERED LLJ AFT
MIDNIGHT AND W/NO REAL PUSH TO SFC BNDRY DOUBT CONVN MAKES IT OUT OF
NWRN ZONES. THUS WILL KEEP W/PRIOR TEMPO TSRA MENTION AT KSBN WHICH
MAY NEED TO BE EXTENDED A BIT FURTHER. HWVR CONVN XPCD TO REMAIN NW
OF KFWA AND DROPPED PREV VCTS MENTION THERE. HIGH BNDRY LYR MSTR
REMAINS IN PLACE AND W/DECAYING SFC GRADIENT AND SOME CLRG OVERNIGHT
XPC SOME FOG TO DVLP.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR LMZ043-046.
&&
$$
SYNOPSIS...T
SHORT TERM...LEWIS
LONG TERM...AGD
AVIATION...T
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AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
212 PM CDT FRI AUG 29 2014
.SYNOPSIS...
ISSUED AT 1244 PM CDT FRI AUG 29 2014
A DEEP RICH MOISTURE PLUME CONTINUES TO FEED INTO EASTERN IOWA AND
MUCH OF THE UPPER MIDWEST. OUR CWA FELL WEST OF A FEW HEAVY RAIN
PRODUCING STORMS IN ILLINOIS EARLIER TODAY...AND UNDER A WEAK AREA
OF SUBSIDENCE THROUGH EARLY AFTERNOON. THIS HAS ALLOWED LOW LEVELS
TO HEAT UP UNINHIBITED. AS OF 1 PM...WIDESPREAD LOWER TO MID 80S ARE
FOUND OVER EASTERN IOWA AND WESTERN ILLINOIS...WITH DEWPOINTS IN THE
70 TO 73 RANGE. HIGHS TODAY SHOULD REACH THE MID TO UPPER 80S. CAPE
VALUES ESTIMATED BY SPC RAP AS OF 1 PM ARE 2000 TO 3000 OVER ALL OF
THE CWA. A VORTICITY MAXIMA IS LOCATED IN EASTERN KS...WITH A PVA
WING OF LIFT FOUND INTO CENTRAL MISSOURI. THIS IS ALREADY DEVELOPING
A LINE OF DEEP CONVECTION FROM NORTH CENTRAL TO SOUTH
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 1244 PM CDT FRI AUG 29 2014
THE VORT MAX TO THE SOUTHWEST WILL LIFT THROUGH IOWA THIS
EVENING...HELPING ORGANIZE STORMS AS THEY MOVE THROUGH THE CWA. FROM
LATE AFTERNOON THROUGH MID EVENING...THESE SHOULD IMPACT MUCH OF THE
CWA. A LACK OF SHEAR SHOULD DECREASE ANY WIDESPREAD SEVERE WEATHER
THREAT...BUT SOME ISOLATED WIND DAMAGE IS POSSIBLE THROUGH WET
MICROBURST ACTIVITY IN THE STRONGEST CELLS. OTHERWISE....THIS SHOULD
BE HEAVY RAIN PRODUCING LINE OF STORMS...WITH SOME BRIEF TRAINING
POSSIBLE. A WIDESPREAD RAIN OF 0.25 TO 0.75 IS EXPECTED...WITH
SWATHS OF 1 TO 2 INCHES. WE ARE LIKELY TO HANDLE THIS MINOR
FLOOD/URBAN RUNOFF THREAT WITH SPS PRODUCTS.
TONIGHT...STORMS SHOULD BECOME LESS NUMEROUS...AND POSSIBLY END
FULLY. HOWEVER...WITH THE PARENT VORT MOVING BY WITH AMPLE
MOISTURE...WE WILL LEAVE POPS GOING THROUGH THE NIGHT.
SATURDAY...MODELS BRING ANOTHER QUICK SHOT OF ENERGY THROUGH WHILE
MOISTURE IS DEPARTING. THIS MAY BRING SOME SHOWERS AND STORMS TO
ROUGHLY THE EAST HALF...BUT SHOULD SUBSIDENCE BECOME MORE CONFIDENT
BEHIND TONIGHTS STORMS...WE MAY BE DRY ALL DAY SATURDAY.
TEMPERATURES LOOK MILD TONIGHT...IN THE UPPER 60S...WHILE SATURDAY
SHOULD SEE A DRY AFTERNOON REBOUND TO THE UPPER 70S TO LOWER 80S.
CLOUDS WHILE THICK IN THE MORNING SHOULD BECOME SCATTERED BY MID
DAY.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 1244 PM CDT FRI AUG 29 2014
THE MAIN FORECAST CONCERN IN THE LONG TERM PERIOD IS STORM
COVERAGE/RAINFALL AMOUNTS/SEVERE POTENTIAL WITH THE ARRIVAL OF THE
NEXT SYSTEM SUNDAY NIGHT INTO MONDAY.
EARLY IN THE PERIOD...HAVE MAINTAINED DRY FORECAST FOR SATURDAY
NIGHT THROUGH SUNDAY AFTERNOON. MEDIUM RANGE MODELS HAVE CONTINUED
A GENERAL TREND OF SLOWING THE ARRIVAL OF THE NEXT FRONTAL
BOUNDARY AND UPPER LEVEL TROUGH. HAVE REDUCED AND TRIMMED POPS
BACK TO THE NORTHWEST FOR SUNDAY EVENING...AND ADDITIONAL
ADJUSTMENTS MAY BE NEEDED OVER THE NEXT COUPLE OF DAYS. THE MAIN
WINDOW OF SHOWERS/STORMS IS NOW EXPECTED LATE SUNDAY NIGHT INTO
MONDAY MORNING. THE LATER TIMING MEANS FAVORABLE SEVERE WEATHER
PARAMETERS WILL LIKELY STAY WEST OF THE FORECAST AREA...WITH THE
MOST LIKELY SCENARIO BEING A DECAYING MCS AND POSSIBLY SOME
LOCALLY HEAVY RAIN. STORMS MAY CONTINUE INTO THE AFTERNOON...AND
POSSIBLY MONDAY NIGHT DEPENDING ON HOW FAR SOUTH THE FRONT PUSHES.
LOOKING AHEAD...CONFIDENCE IN FORECAST DETAILS IS LOWER AS THE
OPERATIONAL GFS AND EURO VACILLATE BETWEEN WEAK TROUGHING AND
ZONAL FLOW ACROSS THE REGION. TIMING AND LOCATION OF THE VARIOUS
WEAK IMPULSES IS CHALLENGING AND RIGHT NOW THERE IS NO REASON TO
VARY FROM THE CONSENSUS BLEND POPS...ESSENTIALLY SLIGHT TO LOW
CHANCE IN EVERY PERIOD THROUGH FRIDAY. TEMPERATURES ARE EXPECTED
TO BE NEAR TO SLIGHT ABOVE NORMAL THROUGH THE PERIOD...WITH
AFTERNOON HIGHS GENERALLY IN THE 8OS AND LOWS IN THE 60S TO LOWER 70S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1244 PM CDT FRI AUG 29 2014
A LARGE AREA OF STORMS WILL SWEEP NORTHEAST THROUGH EASTERN IOWA AND
NORTHWEST ILLINOIS BETWEEN 21Z AND 04Z THIS AFTERNOON AND TONIGHT.
THIS WILL BRING A PERIOD OF IFR/MVFR HEAVY RAIN IN THUNDERSTORMS
WITH MVFR CIGS LIKELY AS WELL. WINDS WILL BE SOUTHERLY TODAY AROUND
12KTS...BECOME WEST TOWARD MORNING. SCATTERED TO ISOLATED SHOWERS
AND STORMS REMAIN A THREAT UNTIL SATURDAY MORNING AROUND 15Z...BUT
COVERAGE. AFTER STORMS MOVE OUT OF THE AREA OVERNIGHT...A MOIST AIR
MASS IN PLACE IS LIKELY TO PRODUCE MVFR CIGS AND VISIBILITY THROUGH
LATE SATURDAY MORNING.
ERVIN
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...ERVIN
SHORT TERM...ERVIN
LONG TERM...ERVIN
AVIATION...RP KINNEY
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1210 AM CDT FRI AUG 29 2014
.SHORT TERM /TONIGHT/...
ISSUED AT 315 PM CDT THU AUG 28 2014
PRIMARY FORECAST QUESTION FOR TONIGHT IS COVERAGE AND TIMING OF
PRECIPITATION. RECENT RADAR TRENDS AND HIGH RESOLUTION MODELS SUCH
AS THE WRF AND HRRR HAVE INDICATED A SIGNIFICANT DECREASING TREND IN
PRECIP COVERAGE LATE THIS AFTERNOON AND EVENING...HOWEVER MOST SHORT
RANGE MODELS CONTINUE TO FORECAST AN INCREASE ONCE AGAIN AFTER DARK
TONIGHT. THIS IS CONSISTENT WITH THE SYNOPTIC SCENARIO CHARACTERIZED
BY BROAD UPPER LEVEL DIFFLUENCE OVER A SATURATED ATMOSPHERE. HAVE
CARRIED GENERALLY CHANCE POPS/SCATTERED WORDING THROUGH THE NIGHT
GIVEN THE SUPPORT FOR REDEVELOPMENT...BUT HAVE LITTLE CONFIDENCE IN
DETAILS OF TIMING AND LOCATION THUS THE POP FORECAST IS BROADBRUSHED
FOR NOW. OTHERWISE LITTLE CHANGE WAS MADE TO THE ONGOING FORECAST.
.LONG TERM /FRIDAY THROUGH THURSDAY/...
ISSUED AT 315 PM CDT THU AUG 28 2014
WITH UPPER LEVEL TROUGH STILL WEST OF THE AREA THROUGH EARLY
SATURDAY MORNING...LIKELY TO SEE SOME ADDITIONAL ROUNDS OF
THUNDERSTORMS ACROSS THE REGION THROUGH THAT TIME. OVER THE NEXT 24
TO 36 HOURS...THE HIGHEST PRECIPITABLE WATER VALUES WILL GRADUALLY
SHIFT EAST OF THE REGION AS H850 MOISTURE TRANSPORT BEGINS TO SHIFT
EAST AS WELL. BY 12Z FRIDAY...ONE ADDITIONAL WAVE...THE KICKER
WAVE...WILL BE LOCATED OVER SOUTHEAST KS/WESTERN MO. THIS SHOULD
LIFT NORTHEAST DURING THE NEXT 24 HOURS RESULTING IN INCREASING LIFT
OVER THE REGION FRIDAY AFTERNOON AND EVENING. IN COMBINATION WITH
THAT A COLD FRONT AND UPPER LEVEL LOW OVER SOUTHERN CANADA WILL
DRIFT SOUTHEAST AND ALSO AID IN DISPLACING THE TROUGH ACROSS THE
GREAT PLAINS. THROUGH THE PERIOD FRIDAY INTO EARLY SATURDAY...
ANOTHER HALF INCH TO INCH OF RAINFALL IS LIKELY TO FALL WITH THE
HEAVIER TOTALS OVER THE NORTH AND NORTHEAST PORTION OF THE FORECAST
AREA. WITH RAINFALL RATES SLOWING DOWN...FLASH FLOODING IS PROBABLY
NO LONGER A THREAT...BUT SATURATED GROUND MAY LEAD TO SOME MINOR
RUNOFF PROBLEMS AT TIMES INCLUDING SOME PONDING OF WATER AND MINOR
STREET FLOODING IN AREAS OF POOR DRAINAGE. TEMPERATURES TOMORROW
WILL LIKELY WARM A BIT IN THE SOUTHEAST IN THE LOWER 80S...AHEAD OF
THE WAVE WITH WARM AIR ADVECTION AND SOME POTENTIAL BREAKS IN THE
CLOUD COVER IN THE SOUTHEAST. AS THE COOL FRONT MOVES EAST PRECIP
CHANCES SHOULD END ACROSS THE REGION SATURDAY MORNING WITH SOME
SUNSHINE RETURNING TO THE AREA BY MORNING. HIGHS WILL BE SLIGHTLY
WARMER...BUT STILL WITHIN THE A FEW DEGREES OF HIGHS OF FRIDAY WITH
MORE SUNSHINE...BUT SOME SLIGHT COOL AIR ADVECTION. MODELS IN
GENERAL AGREEMENT WITH THE NEXT STRONG WAVE EXPECTED TO ARRIVE BY
SUNDAY AFTERNOON....WITH A RATHER WARM DAY AHEAD AS H850 RISE TO
NEAR 20C BY AFTERNOON. THE GFS SHOWS THAT PWATS WILL ONCE AGAIN RISE
TO NEAR OR SLIGHTLY ABOVE 2 INCHES ALONG THE BOUNDARY AS IT MOVES
INTO WESTERN IOWA BY 00Z. UPPER LEVEL WIND FIELDS AGAIN SHOW A
MODEST INCREASE AS A MODESTLY STRONG WAVE APPROACHES FROM THE
SOUTHWEST WITH 0-6KM BULK SHEAR OVER 40 KTS ACROSS THE AREA. THIS
SHOULD BE ENOUGH TO PROMOTE SEVERE STORMS DURING THE LATE AFTERNOON
AND EVENING HOURS. ANOTHER ROUND OF STORMS WITH OVER AN INCH OF RAIN
IN SOME OF THE HEAVIER STORMS IS EXPECTED. FINALLY...THE REMAINDER
OF THE FORECAST SUGGESTS THAT A BREAK FROM THE ACTIVE WEATHER WILL
RETURN FROM LATER ON MONDAY THROUGH WEDNESDAY...WITH SOME POTENTIAL
FOR A QUICK MOVING STORM AGAIN BY THURSDAY.
&&
.AVIATION...29/06Z
ISSUED AT 1210 AM CDT FRI AUG 29 2014
ALL ELEMENTS WILL BE A CONCERN THROUGH THE PERIOD...ESPECIALLY
OVERNIGHT. CONFIDENCE WILL BE LOW AS WELL DUE TO CONVECTION AND
VARIABLE VSBYS AND CIGS. 05Z SURFACE ANALYSIS SHOWS WARM FRONT HAS
LIFTED A BIT TOWARD THE MN BORDER WITH IFR/LIFR CONDITIONS IN THE
VICINITY OVER NRN IA WHICH SHOULD PERSIST UNTIL TYPICAL DIURNAL
RISES. ALSO EXPECT AT LEAST MVFR LIKELY ELSEWHERE DUE TO HIGH LOW
LEVEL MOISTURE LEVELS. CENTRAL IA SHOWERS/STORMS SHOULD CONTINUE
LIFTING N AND E THROUGH THE EARLY MORNING HOURS WITH ASSOCIATED
DEGRADATIONS AS WELL. PRECIP SHOULD DIMINISH WITH RETURN OF VFR
INTO MIDDAY...BUT ADDITIONAL CONVECTION MAY DEVELOP DURING THE
AFTERNOON AND EARLY EVENING HOURS. NOTHING MORE THAN VFR VCSH
WORDING UNTIL CONFIDENCE INCREASES HOWEVER.
&&
.HYDROLOGY...
ISSUED AT 315 PM CDT THU AUG 28 2014
SEVERAL ADDITIONAL EPISODES OF RAIN ARE EXPECTED THROUGH SATURDAY
MORNING AND AGAIN ANOTHER SUNDAY AFTERNOON THROUGH MONDAY MORNING.
AT THIS TIME EXPECTED RAINFALL AMOUNTS THROUGH SATURDAY MORNING WITH
EACH EVENT SHOULD BE LIGHT TO MODERATE. THIS WILL LIMIT THE LIKELIHOOD
OF FLASH FLOODING BUT STILL HAVE SOME EFFECT ON RISES ON SMALL STREAM
AND AREA RIVERS. THERE IS A GREATER RISK OF MORE SUBSTANTIAL RAINFALL
OVER PORTIONS OF THE FORECAST AREA SUNDAY EVENING. THIS TIME PERIOD
WILL BE MONITORED FOR BOTH SHORT TERM FLOODING AND RIVER FLOODING
OVER THE UPCOMING HOLIDAY WEEKEND.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...LEE
LONG TERM...REV
AVIATION...SMALL
HYDROLOGY...REV
AREA FORECAST DISCUSSION
NWS WICHITA KS
256 PM CDT FRI AUG 29 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 256 PM CDT FRI AUG 29 2014
MODERATE INSTABILITY UNDER UPPER TROF ACROSS CENTRAL AND EASTERN
KANSAS WILL SUPPORT SCATTERED DIURNAL CONVECTION LATE THIS
AFTERNOON/EVENING. VISIBLE SATELLITE SHOWED AGITATED CU FIELD
JUST WEST OF WICHITA METRO WITH CONVECTIVE DEVELOPMENT IN RENO
COUNTY SINCE 1930Z. THE RUC AND HRRR WHERE SUGGESTIVE OF CONVECTIVE
DEVELOPMENT ALONG/JUST WEST OF THE TURNPIKE CORRIDOR BEFORE
SHIFTING CHANCES FURTHER EAST THRU THE EVENING. THIS IS HANDLED
FAIRLY WELL IN THE GOING FORECAST. OTHERWISE THE WEEKEND LOOKS TO
BEGIN ON A WARM BUT DRY NOTE FOR MOST OF THE AREA ON SATURDAY AS
THE UPPER TROF MOVES SLOWLY EAST AWAY FROM THE AREA. HOWEVER THE
LATTER PART OF THE HOLIDAY WEEKEND LOOKS A BIT MORE VOLATILE AS
INCREASING WESTERLY FLOW ALOFT OVER THE PACIFIC MOVES ACROSS THE
WESTERN CONUS WITH THE DEVELOPMENT OF A PROGRESSIVE UPPER TROF
MOVING FROM THE CENTRAL/NORTHERN ROCKIES ACROSS THE PLAINS BY LATE
SUNDAY. A MODERATE TO VERY UNSTABLE AIRMASS WILL DEVELOP AHEAD OF
THE ASSOCIATED SURFACE DRYLINE AND COLD FRONT LATE SUNDAY
AFTERNOON AND EVENING ACROSS CENTRAL KANSAS. DIURNAL SURFACE BASED
CONVECTION WILL LIKELY BE SUPPRESSED BY A STOUT CAPPING INVERSION
UNTIL VERY LATE IN THE AFTERNOON OR PERHAPS EARLY EVENING ON
SUNDAY. HOWEVER THE FORCING FOR ASCENT SHOULD BE MORE THAN
SUFFICIENT ALONG THE FRONT WITH DEEP LAYER SHEAR SUPPORTIVE OF A
SEVERE CONVECTIVE EPISODE SUNDAY EVENING INTO PART OF SUNDAY
NIGHT. WHILE THIS COMPLEX WILL LIKELY EXIT STAGE RIGHT BY MONDAY
MORNING...THE SURFACE FRONT IS EXPECTED TO LAY OUT ACROSS SOUTH
CENTRAL INTO EASTERN KANSAS DURING THE DAY. THE COMBINATION OF
DIURNAL HEATING AND A TRAILING SHORTWAVE ALOFT MIGRATING EAST
ACROSS THE AREA SHOULD RESULT IN RENEWED CONVECTION BY LATE
MONDAY. MODERATE TO STRONG INSTABILITY AND SHEAR COULD ALSO GIVE
RISE TO ANOTHER ROUND OF SEVERE STORMS.
DARMOFAL
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 256 PM CDT FRI AUG 29 2014
PLAN TO MAKE LITTLE CHANGES TO THE OUTER PERIODS OF THE
FORECAST...WITH CHANCES FOR CONVECTION WANING AND TEMPERATURES
GRADUALLY WARMING WITH GEOPOTENTIAL HEIGHT RISES EXPECTED AS
THE UPPER RIDGE BUILDS IN ACROSS THE AREA AGAIN DURING THE WEEK.
KED
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1219 PM CDT FRI AUG 29 2014
AS WEAK WIND SHIFT AND ASSOCIATED UPPER TROUGH MOVE ACROSS THE
AREA TODAY...THINKING ISOLATED TO WIDELY SCATTERED
SHOWERS/THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON AND
EVENING...MAINLY EAST OF I-135. FOR NOW INCLUDED VCSH AT ICT-CNU
AFTER 20Z. OTHERWISE...THREAT SHOULD EXIT ICT BY 00Z...AND CNU BY
06Z.
ADK
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 66 92 69 95 / 20 0 10 10
HUTCHINSON 63 92 69 96 / 20 0 10 10
NEWTON 65 91 69 95 / 20 0 10 10
ELDORADO 65 91 68 94 / 30 10 10 10
WINFIELD-KWLD 67 92 69 95 / 30 10 10 10
RUSSELL 63 92 69 96 / 10 10 20 30
GREAT BEND 62 92 69 97 / 10 10 20 20
SALINA 64 93 69 97 / 20 0 20 20
MCPHERSON 64 92 69 96 / 20 0 10 20
COFFEYVILLE 69 91 69 94 / 40 20 20 10
CHANUTE 67 90 68 93 / 40 20 20 10
IOLA 67 89 68 93 / 40 20 10 10
PARSONS-KPPF 68 90 69 94 / 40 20 20 10
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1259 AM CDT FRI AUG 29 2014
.UPDATE...
ISSUED AT 748 PM CDT THU AUG 28 2014
MADE SPATIOTEMPORAL ADJUSTMENTS OF POPS AND WX GRIDS BASED OFF
RADAR TRENDS AS WELL AS HRRR GUIDANCE. CONVECTION IS STRUGGLING,
AND NOT VERY CONFIDENT OF EASTWARD PROPAGATION GIVEN UPCOMING
DECREASE IN DIURNAL INDUCED INSTABILITY AND LACK OF FORMIDABLE
COLD POOL GENERATION FOR MCS LONGEVITY. 00Z KDDC RAOB IS
CONSIDERABLY DRIER WITH A LOWER PWAT OF 1.03".
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 139 PM CDT THU AUG 28 2014
THERE IS A FRONT WHICH HAS BEEN NEARLY STATIONARY TODAY FROM JUST
WEST OF TOPEKA SOUTH-SOUTHWEST TO NEAR ANTHONY, KS AND THEN FURTHER
SOUTHWEST INTO SOUTHWESTERN OKLAHOMA. CONVECTION HAS BEEN ONGOING
AND SPREADING OUT TODAY JUST EAST OF THIS CONVERGENCE BOUNDARY.
ANOTHER SURFACE TROUGH IS QUICKLY MOVING EAST THROUGH OUR CWA,
AND CROSSED DDC AT 1952Z. CLOUDS HAVE BEEN SLOWER TO CLEAR OUT IN
OUR EASTERN CWA THAN IN THE WEST, BUT STILL THINK THERE WILL BE
ENOUGH OF A CONVERCENCE BOUNDARY TO INITIATE SOME THUNDERSTORMS.
AT THIS TIME, I DO NOT EXPECT ANY SEVERE STORMS, WITH THE NAM AND
HRRR MODELS BOTH SHOWING AROUND 1200 TO 1400 J/KG OF MUCAPE THIS
EVENING, AND THE BULK SHEAR VALUES IN THE 18 TO 22 KNOT RANGE.
THERE IS A SMALL CHANCE FOR SOME SMALL HAIL AND DOWN BURST WINDS
IN THE 50 MPH RANGE. I HAVE MIGRATED THE 50-60 PERCENT POPS FROM
DDC TO PTT FROM 22Z TO 02Z. ALSO, THERE IS AN UPPER POOL OF COLD
AIR COMING IN FROM COLORADO THIS EVENING, AND A FEW SHOWERS AND
THUNDERSTORMS MAY TRIGGER OFF THE COLD POOL IN OUR WESTERN ZONES.
THE HEAVIER RAIN CHANCES WILL BE IN OUR EASTERN 2-TIER OF
COUNTIES, WHERE THE FRONT AND TROUGH ARE, DEW POINTS ARE MUCH
HIGHER IN OUR EAST. I DO NOT EXPECT ANY POTENTIAL FLOODING
PROBLEMS OF THE PAST TWO NIGHTS WHICH AFFECTED NESS, SCOTT AND
TREGO COUNTIES.
OVERNIGHT, THE UPPER COLD POOL WILL HELP TO DE-STABILIZE THE
ATMOSPHERE, AND THE RAIN CHANCES WILL MOVE EAST TOWARDS MORNING,
ALONG WITH THE UPPER COLD POOL. THE PRECIPITATION TYPE SHOULD BE
MORE SHOWERY OVERNIGHT VERSUS THE THUNDERSTORM TYPE. WILL STILL
MENTION THE CHANCE FOR SHOWERS AND ISOLATED THUNDER, BECAUSE IT
WON`T TAKE MUCH OF AN UPDRAFT TO UPGRADE A SHOWER INTO A
THUNDERSTORM. BY 12Z, MOST OF ANY CONVECTION WILL BE CONCENTRATED
INTO OUR EASTERN ZONES, AND OUT OF OUR EASTERN ZONES BY 18Z
FRIDAY.
LOW TEMPERATURES TONIGHT SHOULD BE COOLER THAN LAST NIGHT, WITH MINS
RANGING FROM THE UPPER 50S ALONG THE COLORADO BORDER TO THE MID 60S
IN OUR EASTERN CWA FROM HAYS TO MEDICINE LODGE. FRIDAY`S
TEMPERATURES SHOULD MATCH TODAY`S MAX TEMPS VERY SIMILARLY, AND BE
BASICALLY IN THE MIDDLE TO UPPER 80S.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 205 PM CDT THU AUG 28 2014
MEDIUM RANGE MODELS INDICATE AN UPPER LEVEL SHORTWAVE TROUGH LIFTING
NORTHEAST OUT OF THE CENTRAL PLAINS INTO THE UPPER MIDWEST SATURDAY
WHILE WEAK UPPER LEVEL RIDGING BEGINS TO MOVE OUT OF THE ROCKIES
INTO THE WESTERN HIGH PLAINS. ALONG WITH A FAIRLY WEAK FLOW ALOFT,
DRIER CONDITIONS ARE LIKELY THROUGH LATE SATURDAY AFTERNOON. PRECIP
CHANCES PICK UP A LITTLE SATURDAY NIGHT AS AN UPPER LEVEL TROUGH
MOVES EAST-SOUTHEAST ACROSS THE PACIFIC NORTHWEST INTO THE GREAT
BASIN REGION. A SERIES OF H5 VORT MAXIMA WILL BEGIN TO EJECT OUT OF
THE ROCKIES INTO THE WESTERN HIGH PLAINS AS A LOW LEVEL SOUTHEASTERLY
UPSLOPE FLOW SETS UP ACROSS EASTERN AND EXTREME WESTERN KANSAS.
ALTHOUGH THE FLOW ALOFT WILL REMAIN FAIRLY WEAK, MODEST INSTABILITY
WITH CAPE VALUES AROUND 500 TO 1000 J/KG AND FAVORABLE ENOUGH
DIRECTIONAL SHEAR WILL BE PRESENT TO SUPPORT THE POTENTIAL FOR
ISOLATED THUNDERSTORMS ACROSS THE HIGH PLAINS IN THE VICINITY OF A
DEVELOPING LEE SIDE TROUGH. WIDESPREAD SEVERE IS UNLIKELY.
PRECIP CHANCES MAY PICK UP A LITTLE MORE LATE SUNDAY AFTERNOON INTO
SUNDAY NIGHT AS AN OPEN SHORTWAVE TRANSITIONS EASTWARD ACROSS THE
NORTHERN ROCKIES INTO INTO THE NORTHERN PLAINS. AN ATTENDANT COLD
FRONT IS PROJECTED TO PUSH SOUTHEASTWARD INTO WESTERN KANSAS LATE IN
THE DAY WHILE A PREVAILING SOUTHEASTERLY FLOW NEAR THE SURFACE
CONTINUES TO DRAW MOISTURE UP INTO MUCH OF KANSAS. MEANWHILE, A
+90KT UPPER LEVEL JET ASSOCIATED WITH THE OPEN WAVE IS PROJECTED TO
DIG SOUTHEAST ACROSS THE NORTHERN ROCKIES NOSING INTO THE HIGH PLAINS
OF WESTERN NEBRASKA AND POSSIBLY NORTHERN PORTIONS OF WESTERN
KANSAS. AS A RESULT, THUNDERSTORMS ARE LIKELY TO FIRE UP ALONG AND
AHEAD OF THE FRONT AS IT PUSHES EASTWARD INTO THE UPPER MIDWEST
SUNDAY NIGHT. HOWEVER, THUNDERSTORM CHANCES MAY BE MORE LIMITED
FURTHER SOUTH ALONG THE FRONT INTO KANSAS WITH WEAKER DYNAMIC
SUPPORT ALOFT. THE BETTER CHANCE FOR CONVECTION WILL REMAIN
ACROSS OUR NORTHEAST IN CENTRAL KANSAS WHERE LOW LEVEL FORCING
WILL BE MORE IDEAL NORTHEAST OF A DEVELOPING SURFACE LOW ACROSS
EXTREME SOUTHWEST KANSAS. ALTHOUGH LESS CERTAIN, THUNDERSTORMS MAY
BE POSSIBLE AGAIN MONDAY NIGHT INTO EARLY TUESDAY AS THE
AFOREMENTIONED COLD FRONT IS FORECAST TO STALL OUT SOMEWHERE
GENERALLY ALONG THE OKLAHOMA BORDER.
TEMPERATURES ARE EXPECTED TO BE NEAR THE SEASONAL SATURDAY AS
SURFACE PRESSURE BEGINS TO FALL ACROSS EASTERN COLORADO. ALTHOUGH
THIS WILL HELP QUICKLY RETURN A LOW LEVEL SOUTHEASTERLY FLOW TO
WESTERN KANSAS BY SATURDAY AFTERNOON, LITTLE CHANGE IS EXPECTED TO
THE OVERALL AIR MASS IN PLACE ACROSS THE REGION. LOOK FOR HIGHS
ONLY UP INTO THE MID TO UPPER 80S(F) IN CENTRAL KANSAS WITH THE
LOWER 90S(F) POSSIBLE IN EXTREME SOUTHWEST KANSAS WHERE SOME WARM
AIR ADVECTION IS LIKELY BY SATURDAY AFTERNOON. THE WARMING TREND
WILL CONTINUE INTO SUNDAY AS THE PREVAILING SOUTHERLY FLOW DRAWS
WARMER AIR NORTHWARD. WIDESPREAD 90S(F) ARE LIKELY TO FINISH OUT
THE WEEKEND AS A RESULT. COOLER TEMPERATURES ARRIVE MONDAY IN
WAKE OF A COLD FRONT PUSHING THROUGH WESTERN KANSAS BY MID DAY
DROPPING HIGHS BACK DOWN INTO THE 80S(F) TO START THE WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1258 AM CDT FRI AUG 29 2014
NUMEROUS SHOWERS AND A FEW OCCASIONAL LIGHTNING STRIKES WILL AFFECT
THE HAYS TERMINAL OVER THE NEXT ONE TO POSSIBLY TWO HOURS AS AN
UPPER LOW MOVES THROUGH THE HIGH PLAINS REGION. POST FRONTAL SURFACE
WINDS WILL REMAIN LIGHT AND OUT OF THE NORTH UNTIL AT LEAST MID
AFTERNOON FRIDY AT ALL TERMINAL LOCATIONS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 61 90 68 95 / 10 10 10 20
GCK 59 91 67 95 / 10 10 10 20
EHA 61 91 67 97 / 10 10 10 10
LBL 61 91 68 97 / 10 10 10 10
HYS 61 89 68 93 / 10 10 10 40
P28 66 90 69 95 / 10 10 10 30
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SUGDEN
SHORT TERM...BURKE
LONG TERM...JJOHNSON
AVIATION...RUSSELL
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
648 AM EDT Fri Aug 29 2014
...Updated Forecast and Aviation Discussions...
...Forecast Update...
Issued at 635 AM EDT Fri Aug 29 2014
Seeing a few light returns just north of our IN counties. These are
developing on the north edge of a theta-e ridge currently over KHNB.
Latest RUC keeps this going on for a few more hours before the
frontal lift dominates the rest of the morning. Added in some
isolated showers over the west this morning before switching over to
storms this afternoon over the northeast. Rest of forecast pretty
much on track.
Climate Note: BWG received 1.16 inches of rain, bringing their
monthly total to 9.26". This total is the second wettest August on
record for that station. An additional 0.08" over the next 3 days
will tie the record, set back in 1926.
.SHORT TERM (Now through Saturday)...
Issued at 300 AM EDT Fri Aug 29 2014
Weak frontal boundary is roughly located along our southern border
this hour. This boundary is forecast to lift northward today, with a
wind shift from easterly ahead of it to southerly behind it. Lift
along this front as well as instability from late afternoon heating
should produce isolated to scattered storms, with the best chance
over southern Indiana and the Bluegrass region of Kentucky. The
stronger storms will produce brief gusty winds and heavy rain.
Those storms should exit to the northeast this evening before
another round comes in from the west late tonight. This action will
be as a low-level jet aids in development over the Bootheel region
that will shift eastward toward daybreak. Precipitable water values
will climb to near 2 inches during the day. The main focus for
heavier storms will be along another front to our northwest, but any
heating over our region should be able to produce scattered storms.
The main problem with these storms will be the torrential rainfall,
given the high atmospheric moisture. Storm motion vectors indicate
enough motion that we should be able to avoid flash flooding, but
areas that receive multiple rounds of storms could see some minor
flooding, especially in poor drainage areas.
Temperatures will continue above normal this period.
.LONG TERM (Saturday Night through Thursday)...
Issued at 300 AM EDT Fri Aug 29 2014
...Unsettled Weather Through the Holiday Weekend and into Next Week...
Multiple rounds of shower and thunderstorms are expected through the
long term with storms likely for a portion of the holiday weekend. A
weakening upper level trough will cross the upper Midwest Saturday
and move into the Great Lakes region by Sunday morning. Another
vortmax will track northeast through the upper level flow and into
the Lower Ohio Valley Saturday night into Sunday. At the surface
southerly flow will remain in place with high pressure centered off
the east coast.
The best chance for showers and storms during the long term will be
right at the beginning on Saturday night and Sunday as the upper
level disturbances move through the area. Wind fields are not overly
impressive, but a few strong storms will be possible with gusty
winds. However, soundings do reveal a very saturated atmosphere with
PWAT values rising to over 2 inches. Long skinny CAPE is also
suggestive of very heavy rain. Storms should be moving somewhat
quicker than previous episodes of heavy rain we have seen this
month. However, given torrential rainfall potential from storms, if
there is any training some minor flooding issues will be possible.
This would particularly be a concern in urban areas.
Another vortmax will set off another round of showers and storms
Monday afternoon. With drier air filtering in at mid levels PWATs
will drop Monday and heavy rainfall should be less of a concern. By
Tuesday a frontal boundary will drop south towards the area from the
north. This boundary looks to get hung up north of the forecast
area, though the models do have some differences in the details
towards the end of the forecast period. Regardless, scattered
showers and storms will be possible through Thursday along and south
of this front.
Temperatures for the most part will be in the mid 80s to lower 90s.
The exception will be Sunday. With all the clouds and precipitation
in the area temperatures will top out in the lower to mid 80s. Lows
will be in the upper 60s to lower 70s.
&&
.AVIATION (12Z TAF Update)...
Issued at 645 AM EDT Fri Aug 29 2014
KBWG had a few clouds go over the last couple of hours, which
generally has kept them in the MVFR range for vsby. Could still get
an hour or two of IFR conditions down there before going VFR the
rest of the day. May see some light showers west of KSDF by late
morning. The best chance for a storm there would be in the mid
afternoon, but chance is still low enough to keep out of TAFs at
this point. Better chance continues to be at KLEX, as a front moves
north across the region and combines with daytime heating to produce
scattered storms.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Update.........RJS
Short Term.....RJS
Long Term......EER
Aviation.......RJS
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
949 PM CDT SAT AUG 30 2014
.UPDATE...
WE HAVE A FEW CHANGES TO SKY WEST AND POPS AREA WIDE OVERNIGHT.
&&
.DISCUSSION...
VERY FEW 80S LEFT IN THE CWA OVER NE TX...MOST LOCALES NOW IN THE
70S WHERE WE WILL SETTLE DOWN TO THE LOWER END BY DAYBREAK. SKIES
ARE THINNING A BIT AND EVEN CLEARING OVER NE TX. THE SHV 88D IS
NOW IN CLEAR AIR MODE SEARCHING FOR RETURNS WITH LITTLE TO BE
FOUND. THE LAST FEW STREAMERS OF SHOWERS HAVE EXITED UNION PARISH
THIS PAST HOUR. WE HAVE LOWERED POPS IN GENERAL WITH SOME
IMPROVEMENTS TO SKY OVER OUR WEST AS WELL. THE TROPICAL MOISTURE
IS LINGERING...BUT THE UPPER LEVEL SUPPORT IS JUST NOT IN PLACE
ANY LONGER WITH THE WATER VAPOR SHOWING AN UPPER LEVEL HIGH NOW IN
THE WAKE OF THE TROPICAL LOWS YESTERDAY. MUCH OF THAT LEAD VORTICITY
IS NOW OVER E TN AND N GA. MOST MODELS ARE VERY MODEST
OVERNIGHT...BUT THE HRRR MODEL DOES FLICKER IN AND OUT A BIT OF
QPF OVER OUR SOUTHEAST THIRD OR SO WITH HIGH CHANCE POPS THERE.
SLIGHT CHANCES OVER THE NORTHWESTERN HALF OF THE AREA FOR THE
OVERNIGHT HOURS. NO OTHER CHANGES NEEDED AT THIS TIME.
&&
.PREV DISCUSSION... /ISSUED 627 PM CDT SAT AUG 30 2014/
AVIATION...
IFR/LIFR CEILINGS POSSIBLE ACROSS MLU/ELD TERMINAL SITES THROUGH
31/14Z...WITH MVFR CEILINGS POSSIBLE ACROSS THE REMAINDER OF THE
TAF SITES. SOUTH WINDS 5 TO 10 KNOTS TONIGHT TO BECOME SOUTHWEST
AROUND 10 KNOTS ON SUNDAY WITH CONDITIONS IMPROVING TO VFR AREAWIDE
AFTER 31/15Z. OTHERWISE...SCATTERED CONVECTION AGAIN POSSIBLE
ACROSS MLU/ELD/LFK ON SUNDAY AFTERNOON. /05/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 73 92 76 95 75 / 20 20 10 10 10
MLU 72 91 74 94 74 / 40 30 20 10 10
DEQ 72 92 72 93 72 / 20 10 10 10 10
TXK 73 93 74 93 74 / 20 20 10 10 10
ELD 71 91 73 94 73 / 40 20 10 10 10
TYR 74 94 76 95 76 / 10 10 10 10 10
GGG 73 94 75 95 75 / 20 20 10 10 10
LFK 74 94 76 95 76 / 30 30 20 20 20
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
24
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
215 AM EDT FRI AUG 29 2014
.SYNOPSIS...
A WEAK COLD FRONT SETTLES SOUTH INTO NORTH CAROLINA OVERNIGHT
INTO FRIDAY...BEFORE LIFTING NORTH AS A WARM FRONT FRIDAY NIGHT
AND SATURDAY. A WEAK TROUGH DEVELOPS ON SUNDAY AND SHOULD RESULT
IN INCREASING PRECIPITATION CHANCES LATER IN THE DAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
WK SFC BNDRY RMNS DRAPED FM ALG THE VA/NC BORDER IN SRN/SE VA...TO
WCNTRL VA. ISOLD/SCT CONVECTION CONTS TO TRACK SLOLY SE THROUGH
AREAS OF THE PIEDMONT W OF I 95. DEWPTS RMN FM THE U60S TO L70S S
ALONG/S OF THAT BNDRY...AND MNLY IN THE L60S N (ALONG NNE WNDS).
00Z/29 RUC CONT TO PUSH THAT CONVECTION TO THE SE INTO NE NC AFT
MIDNIGHT AS THE BNDRY SINKS S. WILL KEEP POPS FOR THOSE AREAS
UNTIL AFT MDNGT...ELSW JUST CLR-PC. MAY NEED TO ADD FOG OVR SRN
AREAS OF THE FA...THOUGH XPCG A GRADUAL LWRG OF DEWPTS FM THE NNE
AS THE BNDRY SINKS TO THE S. LO TEMPS FM THE L60S N TO THE
U60S/ARND 70F S.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY/...
A WEAK FRONTAL BOUNDARY REMAINS STALLED ACROSS NRN NC FRIDAY AS A
SFC HIGH PRESSURE OVER NEW ENGLAND EXTENDS SWD INTO THE MID ATLANTIC
REGION. ONCE AGAIN...THE WEAK FRONTAL BOUNDARY SHOULD PROVIDE JUST
ENOUGH FORCING/INSTABILITY FOR ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS INVOF THE STALLED FRONT (STILL PRIMARILY SOUTH OF
INTERSTATE 64 WITH BEST PRECIP CHANCES ALONG THE VA/NC BORDER INTO
NE NC). THE AXIS OF THE SFC HIGH SITS OVER CNTRL NY TO CNTRL VA
FRIDAY MORNING AND THEN PIVOTS EWD ALONG THE COAST FROM NC TO NEW
ENGLAND BY FRIDAY EVENING. THIS WILL BRING A SLIGHTLY COOLER AIRMASS
ACROSS THE NRN HALF OF THE CWA WHILE TEMPS STAY ON THE COOLER SIDE
INVOF THE FRONT DUE TO PARTLY TO MOSTLY CLOUDY SKIES. IT IS
DIFFICULT TO SAY EXACTLY WHERE THE DIVIDING LINE WILL SET-UP BTWN
HIGHS IN THE MID-UPPER 80S SW TO LOW-MID 80S NE. CURRENT FORECAST
THINKING GENERALLY KEEPS THE COOLER HIGHS ACROSS THE NRN NECK/MD
LOWER EASTERN SHORE/ACCOMACK COUNTY VA...DESPITE MOSTLY SUNNY SKIES
ACROSS THESE AREAS.
THE STALLED BOUNDARY LIFTS NWD AS A WARM FRONT FRIDAY NIGHT INTO
SATURDAY AS THE SFC HIGH OVER NEW ENGLAND SLIDES OFF THE NEW
ENGLAND COAST LATE FRIDAY NIGHT INTO SATURDAY. AS IT DOES SO...
WILL NEED TO CARRY SLIGHT CHC POPS ACROSS MUCH OF THE FA FRIDAY
NIGHT...WITH THE BEST CHANCES FOR PRECIPITATION (STILL IN THE
20 PERCENT RANGE) ALONG AND N-NE OF INTERSTATE 64 DURING MOST OF
SATURDAY. RETURN FLOW ALSO DEVELOPS ON SATURDAY AS THE RIDGE AXIS
MOVES OFFSHORE...BRINGING WARMER TEMPS AND A MORE HUMID AIRMASS
INTO THE REGION. LOWS FRIDAY NIGHT IN THE LOW-MID 60S NORTH AND
UPPER 60S TO LOWER 70S SOUTH. HIGHS SATURDAY AROUND 90/MID-UPPER
80S IMMEDIATE COAST. A GENERALLY DRY FORECAST FOR SATURDAY NIGHT
INTO THE FIRST HALF OF SUNDAY AS HIGH PRESSURE DOMINATES AT THE
SFC AND ALOFT. LOWS SATURDAY NIGHT AROUND 70 UNDER PARTLY CLOUDY
SKIES. A WEAK TROUGH DEVELOPS ALONG THE LEE OF THE APPALACHIANS ON
SUNDAY AND MAY BE JUST ENOUGH OF A FOCUSING MECHANISM FOR SHOWERS
AND THUNDERSTORMS DURING THE AFTN/EVENING AS WEAK SHORTWAVE ENERGY
STREAMS ALONG THE PERIPHERY OF AN UPPER LEVEL RIDGE...WHICH SHOULD
BE CENTERED OVER THE WRN ATLANTIC AS A BERMUDA HIGH. MID-RANGE
MODEL SOLUTIONS VARY REGARDING OVERALL PRECIPITATION PLACEMENT...
BUT THE GENERAL TREND HAS HIGHER POPS OF 30-40 PERCENT ALONG AND
NW OF A LINE FROM AVC-RIC-SBY AND LOWER POPS AROUND 20 PERCENT
ACROSS NE NC/FAR SE VA. TEMPERATURES REMAIN WARM IN THE PERSISTENT
RETURN FLOW WITH HIGHS ONCE AGAIN AROUND 90/MID-UPPER 80S IMMEDIATE
COAST.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
SUMMER-LIKE PATTERN WILL TEND TO PREVAIL THROUGH THE MEDIUM RANGE PERIOD
AS MID/UPPER LEVEL RIDGING CENTERED ALONG/OFF THE SE US COAST...GRADUALLY
SHIFTS TO THE WSW AND BECOMES ANCHORED OVER THE DEEP SOUTH/GULF
COAST REGION. TEMPERATURES WILL GENLY RUN ABOUT 5 F ABOVE AVG WITH
HIGHS INTO THE UPPER 80S TO LOWER 90S AND LOWS IN THE UPPER 60S TO
LOWER/MID 70S. A COUPLE OF WEAK MID LEVEL SHORTWAVES WILL BRING
SOMEWHAT HIGHER POPS TO THE AREA FOR LABOR DAY...WILL CARRY 40%
POPS THROUGHOUT...FOLLOWED BY POPS ONLY ~20% ON TUE IN BETWEEN THE
DEPARTING WAVE AND A COLD FRONT APPROACHING FROM THE NW. TUE
LIKELY THE HOTTEST DAY..WITH MOST LOCATIONS GETTING ABOVE 90 F AND
PERHAPS INTO THE MID 90S OVER THE INTERIOR. ANOTHER ROUND OF
SOMEWHAT HIGH POPS IS SLATED FOR TUE EVENING/TUE NIGHT AS THE COLD
FRONT MOVES CLOSER TO THE LOCAL AREA AND HEIGHTS ALOFT DROP AS THE
RIDGE BREAKS DOWN.
BY LATE WED-THU...A GENERAL CONSENSUS OF THE GFS/ECMWF/WPC
FORECAST DOES PUSH A SFC COLD FRONT SOUTH OF THE AREA WITH HIGH
PRESSURE BUILDING ACRS THE NE CONUS. THIS SHOULD ALLOW SLIGHTLY
COOLER/DRIER AIR TO MOVE INTO THE REGION...BUT THE FRONT DOES NOT
LOOKS VERY STRONG SO HIGHS WILL STILL AVG IN THE MID-UPPER 80S ON
THU. WILL FOCUS HIGHEST POPS WED-THU ACRS THE SOUTH (20-30%) WITH
GENLY A DRY FORECAST ACRS THE ERN SHORE.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
THE SURFACE FRONT HAS STALL JUST SOUTH OF THE AREA AND A BAND OF
SHOWERS AND THUNDERSTORMS HAS FORMED JUST ON THE NORTH SIDE OF THE
FRONT. THIS CONVECTION IS SLOWLY SLIDING SE AND LOOKS LIKE IT WILL
MISS ECG...BUT IS PROVIDING SOME OVERCAST CONDITIONS FOR
PHF/ORF/ECG. THIS CLOUD COVER SHOULD KEEP ANY GROUND FOG FROM
FORMING. SBY IS DEEPER INTO THE DRIER AIR MASS TO THE NORTH AND IS
CLEAR TO BEGIN THE PERIOD. THIS LOOKS LIKELY TO CONTINUE THROUGH
THE OVERNIGHT HOURS.
ON FRIDAY...THE FRONTAL BOUNDARY WILL BEGIN TO LIFT BACK NORTH AS
A WARM FRONT. THE MODELS DIFFER ON HOW MUCH CLOUD COVER WILL
EXIST...BUT CEILINGS SHOULD REMAIN AROUND 5K TO 8K FT. FOR NOW
HAVE ALLOWED FOR A BKN CEILING DURING THE AFTERNOON HOURS ACROSS
VA INTO NE NC. FURTHER NORTH NEAR SBY HAVE JUST ALLOWED FOR SOME
SCATTERED CU TO FORM. THE MID DECK CLOUDS CONTINUE ACROSS VA AND
NERN NC TONIGHT AS THE FRONT SLOWLY EDGES NORTHWARD. BUT AT THIS
POINT...ALL CEILINGS SHOULD REMAIN IN THE VFR RANGE.
OUTLOOK...MAINLY DRY WEATHER WITH CONTINUED VFR CONDITIONS EXPECTED
FRIDAY AND THROUGH MUCH OF THE UPCOMING HOLIDAY WEEKEND. SLIGHT TO
LOW CHANCE POPS FOR AFTN/EVENING TSTMS SUNDAY EVENING INCREASE TO
30 TO 40 PERCENT MONDAY AHEAD OF THE NEXT FRONTAL PASSAGE.
OTHERWISE, SOME POTENTIAL FOR FOG OR LOW CLOUDS WILL EXIST EACH
DAY WITHIN A FEW HOURS OF SUNRISE.
&&
.MARINE...
CRISTOBAL NOW >500 NM ENE OF THE LOCAL AREA...WITH A WEAK SFC
BOUNDARY HAVE PUSHED SOUTH OF THE WATERS. N/NE WINDS AVG AROUND 10
KT...WILL LIKELY INCREASE A BIT LATER TONIGHT AS MODEST PUSH OF
COOLER AIR MOVES OVER THE WATERS WITH SFC HIGH PRESSURE MOVING ESE
FROM MICHIGAN INTO THE NE AND NRN MID ATLC REGION.
AS FOR HEADLINES...WILL MAINTAIN SCHS HEADLINE FOR COASTAL WATERS N
OF PARRAMORE ISLAND THROUGH 10PM...WITH NO HEADLINES ELSEWHERE EVEN
THOUGH THERE WILL BE SOME INCREASE IN WINDS OVER THE BAY OVERNIGHT
INTO EARLY FRI. (MUCH LIKE WHAT OCCURRED EARLIER TODAY). N/NE
WINDS WILL SLOWLY VEER TO THE E/NE IN THE AFTN AND AVG 10-15 KT
ACRS THE LOWER BAY AND SOUTHERN COASTAL WATERS TO 5-10 KT FARTHER
NORTH. SEAS WILL GENLY ONLY BE AROUND 3 FT...BUT WILL GENLY STILL
HAVE A MODERATE RISK FOR RIP CURRENTS ALONG AREA BEACHES AS ENERGY
FROM CRISTOBAL IS SLOW TO DIMINISH.
WINDS THEN GRADUALLY VEER AND BECOME SE AND GRADUALLY INCREASE BY
SATURDAY AFTN/EVENING. WINDS THEN BECOME S/SW SUNDAY. SEAS WILL
GENERALLY RUN 3 FT OR LESS BUT MAY INCREASE TO 4 FT IN THE OUTER
PORTION OF 20NM LATE SATURDAY AND SUNDAY...WITH A PERIOD OF 2-3 FT
WAVES IN THE BAY SAT NIGHT. FAIRLY QUIET (OUTSIDE OF CONVECTION) INTO
EARLY NEXT WEEK WITH SEAS 2-3 FT AND WAVES 1-2 FT OR LESS AS SFC
HIGH REMAINS ANCHORED OFFSHORE AND NO SIGNIFICANT FRONTS MOVE INTO
THE AREA UNTIL LATE TUE/WED.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...MODERATE RIP CURRENT RISK THROUGH THIS EVENING FOR MDZ025.
NC...MODERATE RIP CURRENT RISK THROUGH THIS EVENING FOR NCZ102.
VA...MODERATE RIP CURRENT RISK THROUGH THIS EVENING FOR VAZ098>100.
MARINE...NONE.
&&
$$
SYNOPSIS...ALB/BMD/JDM
NEAR TERM...ALB/BMD
SHORT TERM...BMD
LONG TERM...LKB
AVIATION...ESS
MARINE...LKB
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1133 AM EDT FRI AUG 29 2014
LATEST UPDATE...
UPDATE/MARINE
.SYNOPSIS...
ISSUED AT 325 AM EDT FRI AUG 29 2014
SHOWERS AND A FEW THUNDERSTORMS ARE POSSIBLE TODAY AS A WARM FRONT
MOVES THROUGH THE AREA. MORE WIDESPREAD THUNDERSTORM ACTIVITY IS
EXPECTED SATURDAY AHEAD OF THE COLD FRONT...WHICH COMES THROUGH
EARLY SUNDAY MORNING. BEHIND THE COLD FRONT ON SUNDAY EXPECT
PARTIAL CLEARING BY AFTERNOON. THEN A STRONG COLD FRONT WILL BRING
THE RISK OF ADDI TONAL STORMS MONDAY.
&&
.UPDATE...
ISSUED AT 1130 AM EDT FRI AUG 29 2014
LOWERED TEMPERATURES SLIGHTLY AND ADDED A RISK FOR THUNDERSTORMS
THIS AFTERNOON. ELEVATED INSTABILITY MOVES IN FOR THE AFTERNOON.
ALSO RADAR SHOWS CONVECTION CROSSING THE LAKE. CLOUDS WILL LIKELY
LIMIT HIGH TEMPERATURES TODAY. WARMEST READINGS MAY BE LATER IN
THE AFTERNOON WHEN WE WILL POTENTIALLY SEE MORE SUN.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 325 AM EDT FRI AUG 29 2014
WE ARE TRACKING SHOWERS AND THUNDERSTORMS TODAY THROUGH SATURDAY
NIGHT. WHILE THERE COULD BE SOME SHOWERS AND ISOLATED THUNDERSTORMS
AROUND TODAY....IT WOULD SEEM OUR BEST POTENTIAL FOR WIDESPREAD
CONVECTION IS SATURDAY AS THE UPPER WAVE MOVES THROUGH.
THE BIG PICTURE FINDS A OPENING UP SOUTHERN STREAM CLOSED UPPER
LOW MOVING EAST AS IT SHEARS OUT AND MOVES OVER MICHIGAN DURING
THE DAY TIME SATURDAY. THE MODELS AS NEARLY ALWAYS WEAK THESE
FEATURE TO FAST SO I WOULD EXPECT STRONG DYNAMICS SATURDAY THEN
ANY OF THE MODELS CURRENTLY WOULD SUGGEST. IN ANY EVENT AS THIS
UPPER WAVE HEADS TOWARD MICHIGAN IT DISPLACES A SHORTWAVE RIDGE
CURRENTLY IN PLACE OVER MICHIGAN. THAT RESULTS IN A SURGE OF MID
LEVEL MOISTURE THAT SHOULD LEAD TO SOME SHOWER AND THUNDERSTORM
ACTIVITY OVER THE WESTERN AND NORTHER SECTIONS OF THE CWA TODAY.
THEN THE PASSAGE OF THE MAIN SYSTEM SATURDAY WILL BRING MORE
WIDESPREAD CONVECTION TO THE AREA.
LOOKING AT THE 1000/850 MOISTURE TRANSPORT VECTORS FROM THE
GFS...NAM AND ECMWF FOR TODAY THE STORY THEY TELL IS SIMILAR TO
WHAT THEY SHOWED YESTERDAY AND THE DAY BEFORE THAT. FOR THE MOST
PART THE BEST MOISTURE TRANSPORT WILL BE NORTH AND WEST OF THE GRR
CWA TODAY. THE LOW LEVEL JET AXIS IS WEST OF MICHIGAN EARLY THIS
MORNING AND IS MOSTLY OVER NORTHERN LOWER AND UPPER MICHIGAN THIS
AFTERNOON INTO TONIGHT. ALSO THE INSTABILITY IS RATHER LIMITED AND
WHAT THERE IS OF IT IS MOSTLY OVER WESTERN SECTIONS OF LOWER
MICHIGAN INTO THIS AFTERNOON. THE SHORTWAVE RIDGE AHEAD OF THE
UPPER WAVE HAS BROUGHT TO WARM OF AIR ABOVE 700 MB SO THAT
VERTICAL TOTALS ARE MARGINAL AT BEST FOR THUNDERSTORMS TODAY. WHAT
BRING THE SHOWERS TO THE AREA TODAY IS A SURGE OF MID LEVEL
MOISTURE AS THE PRECIPITABLE WATER SURGES FROM UNDER A SEVEN TENTS
OF AN INCH EARLY THIS MORNING TO ABOVE ONE AND THREE QUARTER
INCHES OVER MOST OF THE CWA BY NOON. THE FOCUS OF THIS WILL BE ON
THE WARM FRONT NEAR THE AXIS OF THE LOW LEVEL JET. THAT MEANS MOST
OF THE CONVECTION WILL BE NORTH AND WEST OF THE GRR CWA TODAY.
SATURDAY IS WHEN THE MAIN UPPER WAVE MOVES THROUGH THE AREA AND
THERE IS WORKABLE LOW LEVEL JET IN THE AREA AND SOME UPPER LEVEL
JET SUPPORT SO WE SHOULD HAVE WIDESPREAD SHOWERS AND A FEW NON
SEVERE THUNDERSTORMS (CAPE IS LIMITED AND DEEP LAYER SHEAR IS WEAK
TOO).
ALL OF THIS MOVES OUT SATURDAY NIGHT AND SUNDAY FINES US WITH
SHORT WAVER RIDING. SO I EXPECT CLEARING TO OCCUR DURING THE DAY
SUNDAY AS DRY AIR MOVES IN FROM THE NORTHWEST.
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY) ISSUED AT 325 AM
EDT FRI AUG 29 2014
THE MAIN WEATHER IN THE LONG TERM WILL BE FOCUSED ON THE CONVECTION
CHCS EARLY ON IN THE PERIOD WITH A SYSTEM THAT WILL BE MOVING
THROUGH THE AREA. THE AREA WILL SEE A BREAK IN THE WEATHER FOR SUN
NIGHT IN THE WAKE OF THE DEPARTING SYSTEM FROM SAT/SAT NIGHT...AND
WELL OUT AHEAD OF THE SYSTEM POISED TO MOVE THROUGH THE AREA ON MON.
THE BREAK WILL BE A SHORT ONE AS THE STORM CHCS WILL BE INCREASING
ON MON MORNING AND LASTING INTO MON EVENING. SHORT WAVE ENERGY
EXPECTED TO COME ONSHORE ACROSS OREGON ON SAT WILL TRAVERSE THE
COUNTRY OVER THE HOLIDAY WEEKEND AND WILL BE LIFTING INTO ONTARIO BY
MON AFTERNOON. THE SHORT WAVE REMAINS MAINLY NORTH OF THE AREA.
HOWEVER THE ASSOCIATED LLJ AND STRONG MOISTURE TRANSPORT DOES MOVE
RIGHT INTO THE AREA MON. WE ENVISION A RESIDUAL LINE OF SHOWERS/
STORMS COMING INTO THE AREA FROM THE WEST ON MON...AND STRENGTHENING
AS IT ENCOUNTERS AN INCREASINGLY UNSTABLE AIR MASS WITH DIURNAL
HEATING THAT TAKES PLACE.
WE CAN NOT RULE SOME OF THE STORMS BECOMING SEVERE MON. DEEP LAYER
SHEAR WILL BE ON THE INCREASE WITH THE UPPER JET NEARBY. LI/S ARE
EXPECTED TO DROP DOWN AROUND -6C WITH CAPES APPROACHING OVER 1500
J/KG. THE LLJ OVERHEAD WILL INCREASE THE 0-3 KM SHEAR WHICH WILL
HELP THE CAUSE. THE LIMITATIONS OF POSSIBLE SEVERE WEATHER WOULD BE
LIMITED INSTABILITY IF NOT MUCH HEATING CAN TAKE PLACE...AND NOT
IDEAL UPPER JET DYNAMICS OVERHEAD.
MOST OF THE REST OF THE WEEK SHOULD BE RATHER QUIET AND SEASONABLE
FOR THE AREA. SOME RESIDUAL CHCS OF PCPN WILL HOLD ON TUE UNTIL THE
SECONDARY SHORT WAVE MOVES THROUGH. AFTER THAT...WE GET INTO A
NEARLY ZONAL FLOW WITH LOWER MICHIGAN JUST DOWNSTREAM OF SOME
RIDGING.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 740 AM EDT FRI AUG 29 2014
ALL OF THE HIGH RESOLUTION MODELS (HRRR 09Z AND RAP 10Z) SHOW THE
AREA OF SCATTERED SHOWERS OVER LAKE MICHIGAN BECOMING A SOLID AREA
OF SHOWERS WITH EMBEDDED HEAVER RAIN SHOWERS (INSTABILITY QUESTIONABLE
FOR THUNDERSTORMS). THE AREA OF SHOWERS WILL IMPACT THE TAF SITES
FROM AROUND 15Z TILL AROUND 21Z BEFORE DISSIPATING.
I ALSO ADDED MVFR CIGS AFTER 07Z IN THE WESTERN TAF SITES TO
REFLECT INCREASED LOW LEVEL MOISTURE ADVECTION AS THE UPPER
SHORTWAVE GETS CLOSER TO LOWER MICHIGAN. SO EXPECT MVFR VSBY/CIGS
IN SHOWERS AT MOST OF THE TAR SITES FROM 15Z TILL 19Z....THEN
BECOMING VFR.
&&
.MARINE...
ISSUED AT 1130 AM EDT FRI AUG 29 2014
KEPT THE HAZARDS GOING. SOUTHEAST WINDS BECOME MORE SOUTHERLY AND
INCREASE. THIS SHOULD RESULT IN WAVES POTENTIALLY CLIMBING ABOVE 4 FT.
&&
.HYDROLOGY...
ISSUED AT 328 PM EDT THU AUG 28 2014
THE HEAVY RAIN THREAT APPEARS TO BE LIMITED TO THE MUSKEGON AND
PERE MARQUETTE BASINS AS AN INCH OF QPF CAN BE EXPECTED THERE BY
SUNDAY MORNING...WHICH WOULD RESULT IN RISES BY EARLY NEXT WEEK.
MUCH LESS RAIN IS EXPECTED IN THE GRAND AND KALAMAZOO RIVER
BASINS.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...BEACH HAZARDS STATEMENT FROM 8 PM EDT THIS EVENING THROUGH
SATURDAY EVENING FOR MIZ037-043-050-056-064-071.
LM...SMALL CRAFT ADVISORY UNTIL 11 PM EDT SATURDAY FOR LMZ848-849.
SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 11 PM EDT
SATURDAY FOR LMZ844>847.
&&
$$
UPDATE...MJS
SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...NJJ
AVIATION...WDM
HYDROLOGY...OSTUNO
MARINE...MJS
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
742 AM EDT FRI AUG 29 2014
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 325 AM EDT FRI AUG 29 2014
SHOWERS AND A FEW THUNDERSTORMS ARE POSSIBLE TODAY AS A WARM FRONT
MOVES THROUGH THE AREA. MORE WIDESPREAD THUNDERSTORM ACTIVITY IS
EXPECTED SATURDAY AHEAD OF THE COLD FRONT...WHICH COMES THROUGH
EARLY SUNDAY MORNING. BEHIND THE COLD FRONT ON SUNDAY EXPECT
PARTIAL CLEARING BY AFTERNOON. THEN A STRONG COLD FRONT WILL BRING
THE RISK OF ADDI TONAL STORMS MONDAY.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 325 AM EDT FRI AUG 29 2014
WE ARE TRACKING SHOWERS AND THUNDERSTORMS TODAY THROUGH SATURDAY
NIGHT. WHILE THERE COULD BE SOME SHOWERS AND ISOLATED THUNDERSTORMS
AROUND TODAY....IT WOULD SEEM OUR BEST POTENTIAL FOR WIDESPREAD
CONVECTION IS SATURDAY AS THE UPPER WAVE MOVES THROUGH.
THE BIG PICTURE FINDS A OPENING UP SOUTHERN STREAM CLOSED UPPER
LOW MOVING EAST AS IT SHEARS OUT AND MOVES OVER MICHIGAN DURING
THE DAY TIME SATURDAY. THE MODELS AS NEARLY ALWAYS WEAK THESE
FEATURE TO FAST SO I WOULD EXPECT STRONG DYNAMICS SATURDAY THEN
ANY OF THE MODELS CURRENTLY WOULD SUGGEST. IN ANY EVENT AS THIS
UPPER WAVE HEADS TOWARD MICHIGAN IT DISPLACES A SHORTWAVE RIDGE
CURRENTLY IN PLACE OVER MICHIGAN. THAT RESULTS IN A SURGE OF MID
LEVEL MOISTURE THAT SHOULD LEAD TO SOME SHOWER AND THUNDERSTORM
ACTIVITY OVER THE WESTERN AND NORTHER SECTIONS OF THE CWA TODAY.
THEN THE PASSAGE OF THE MAIN SYSTEM SATURDAY WILL BRING MORE
WIDESPREAD CONVECTION TO THE AREA.
LOOKING AT THE 1000/850 MOISTURE TRANSPORT VECTORS FROM THE
GFS...NAM AND ECMWF FOR TODAY THE STORY THEY TELL IS SIMILAR TO
WHAT THEY SHOWED YESTERDAY AND THE DAY BEFORE THAT. FOR THE MOST
PART THE BEST MOISTURE TRANSPORT WILL BE NORTH AND WEST OF THE GRR
CWA TODAY. THE LOW LEVEL JET AXIS IS WEST OF MICHIGAN EARLY THIS
MORNING AND IS MOSTLY OVER NORTHERN LOWER AND UPPER MICHIGAN THIS
AFTERNOON INTO TONIGHT. ALSO THE INSTABILITY IS RATHER LIMITED AND
WHAT THERE IS OF IT IS MOSTLY OVER WESTERN SECTIONS OF LOWER
MICHIGAN INTO THIS AFTERNOON. THE SHORTWAVE RIDGE AHEAD OF THE
UPPER WAVE HAS BROUGHT TO WARM OF AIR ABOVE 700 MB SO THAT
VERTICAL TOTALS ARE MARGINAL AT BEST FOR THUNDERSTORMS TODAY. WHAT
BRING THE SHOWERS TO THE AREA TODAY IS A SURGE OF MID LEVEL
MOISTURE AS THE PRECIPITABLE WATER SURGES FROM UNDER A SEVEN TENTS
OF AN INCH EARLY THIS MORNING TO ABOVE ONE AND THREE QUARTER
INCHES OVER MOST OF THE CWA BY NOON. THE FOCUS OF THIS WILL BE ON
THE WARM FRONT NEAR THE AXIS OF THE LOW LEVEL JET. THAT MEANS MOST
OF THE CONVECTION WILL BE NORTH AND WEST OF THE GRR CWA TODAY.
SATURDAY IS WHEN THE MAIN UPPER WAVE MOVES THROUGH THE AREA AND
THERE IS WORKABLE LOW LEVEL JET IN THE AREA AND SOME UPPER LEVEL
JET SUPPORT SO WE SHOULD HAVE WIDESPREAD SHOWERS AND A FEW NON
SEVERE THUNDERSTORMS (CAPE IS LIMITED AND DEEP LAYER SHEAR IS WEAK
TOO).
ALL OF THIS MOVES OUT SATURDAY NIGHT AND SUNDAY FINES US WITH
SHORT WAVER RIDING. SO I EXPECT CLEARING TO OCCUR DURING THE DAY
SUNDAY AS DRY AIR MOVES IN FROM THE NORTHWEST.
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY) ISSUED AT 325 AM
EDT FRI AUG 29 2014
THE MAIN WEATHER IN THE LONG TERM WILL BE FOCUSED ON THE CONVECTION
CHCS EARLY ON IN THE PERIOD WITH A SYSTEM THAT WILL BE MOVING
THROUGH THE AREA. THE AREA WILL SEE A BREAK IN THE WEATHER FOR SUN
NIGHT IN THE WAKE OF THE DEPARTING SYSTEM FROM SAT/SAT NIGHT...AND
WELL OUT AHEAD OF THE SYSTEM POISED TO MOVE THROUGH THE AREA ON MON.
THE BREAK WILL BE A SHORT ONE AS THE STORM CHCS WILL BE INCREASING
ON MON MORNING AND LASTING INTO MON EVENING. SHORT WAVE ENERGY
EXPECTED TO COME ONSHORE ACROSS OREGON ON SAT WILL TRAVERSE THE
COUNTRY OVER THE HOLIDAY WEEKEND AND WILL BE LIFTING INTO ONTARIO BY
MON AFTERNOON. THE SHORT WAVE REMAINS MAINLY NORTH OF THE AREA.
HOWEVER THE ASSOCIATED LLJ AND STRONG MOISTURE TRANSPORT DOES MOVE
RIGHT INTO THE AREA MON. WE ENVISION A RESIDUAL LINE OF SHOWERS/
STORMS COMING INTO THE AREA FROM THE WEST ON MON...AND STRENGTHENING
AS IT ENCOUNTERS AN INCREASINGLY UNSTABLE AIR MASS WITH DIURNAL
HEATING THAT TAKES PLACE.
WE CAN NOT RULE SOME OF THE STORMS BECOMING SEVERE MON. DEEP LAYER
SHEAR WILL BE ON THE INCREASE WITH THE UPPER JET NEARBY. LI/S ARE
EXPECTED TO DROP DOWN AROUND -6C WITH CAPES APPROACHING OVER 1500
J/KG. THE LLJ OVERHEAD WILL INCREASE THE 0-3 KM SHEAR WHICH WILL
HELP THE CAUSE. THE LIMITATIONS OF POSSIBLE SEVERE WEATHER WOULD BE
LIMITED INSTABILITY IF NOT MUCH HEATING CAN TAKE PLACE...AND NOT
IDEAL UPPER JET DYNAMICS OVERHEAD.
MOST OF THE REST OF THE WEEK SHOULD BE RATHER QUIET AND SEASONABLE
FOR THE AREA. SOME RESIDUAL CHCS OF PCPN WILL HOLD ON TUE UNTIL THE
SECONDARY SHORT WAVE MOVES THROUGH. AFTER THAT...WE GET INTO A
NEARLY ZONAL FLOW WITH LOWER MICHIGAN JUST DOWNSTREAM OF SOME
RIDGING.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 740 AM EDT FRI AUG 29 2014
ALL OF THE HIGH RESOLUTION MODELS (HRRR 09Z AND RAP 10Z) SHOW THE
AREA OF SCATTERED SHOWERS OVER LAKE MICHIGAN BECOMING A SOLID AREA
OF SHOWERS WITH EMBEDDED HEAVER RAIN SHOWERS (INSTABILITY QUESTIONABLE
FOR THUNDERSTORMS). THE AREA OF SHOWERS WILL IMPACT THE TAF SITES
FROM AROUND 15Z TILL AROUND 21Z BEFORE DISSIPATING.
I ALSO ADDED MVFR CIGS AFTER 07Z IN THE WESTERN TAF SITES TO
REFLECT INCREASED LOW LEVEL MOISTURE ADVECTION AS THE UPPER
SHORTWAVE GETS CLOSER TO LOWER MICHIGAN. SO EXPECT MVFR VSBY/CIGS
IN SHOWERS AT MOST OF THE TAR SITES FROM 15Z TILL 19Z....THEN
BECOMING VFR.
&&
.MARINE...
ISSUED AT 325 AM EDT FRI AUG 29 2014
WE WILL BE HOISTING A SMALL CRAFT ADVISORY FOR THE NRN MARINE ZONES
FOR TODAY AND LASTING THROUGH SAT. WE WILL ALSO HOIST A SMALL CRAFT
ADVISORY FOR THE REMAINDER OF THE ZONES FOR TONIGHT AND SAT. THE
GRADIENT WILL BE INCREASING AHEAD OF THE INCOMING SYSTEM OUT OF THE
SOUTH. THIS WILL LAST INTO SAT EVENING BEFORE IT DIMINISHES A BIT.
&&
.HYDROLOGY...
ISSUED AT 328 PM EDT THU AUG 28 2014
THE HEAVY RAIN THREAT APPEARS TO BE LIMITED TO THE MUSKEGON AND
PERE MARQUETTE BASINS AS AN INCH OF QPF CAN BE EXPECTED THERE BY
SUNDAY MORNING...WHICH WOULD RESULT IN RISES BY EARLY NEXT WEEK.
MUCH LESS RAIN IS EXPECTED IN THE GRAND AND KALAMAZOO RIVER
BASINS.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...BEACH HAZARDS STATEMENT FROM THIS EVENING THROUGH SATURDAY
EVENING FOR MIZ037-043-050-056-064-071.
LM...SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO 11 PM EDT
SATURDAY FOR LMZ848-849.
SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 11 PM EDT
SATURDAY FOR LMZ844>847.
&&
$$
SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...NJJ
AVIATION...WDM
HYDROLOGY...OSTUNO
MARINE...NJJ
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1209 PM CDT FRI AUG 29 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 338 AM CDT FRI AUG 29 2014
RATHER UGLY MORNING OUT THERE IN TERMS OF AVIATION...WITH PLENTIFUL
AMOUNTS OF LOW CIGS AND FOG OUT AHEAD OF A WARM FRONT THAT WAS
STARTING TO MAKE PROGRESS NORTH INTO MN AND AT 3 AM WAS NEAR THE
I-90 CORRIDOR. BESIDE THE LOW CLOUDS...ISENTROPIC LIFT AND ELEVATED
INSTABILITY ADVECTION ASSOCIATED WITH A MODEST 20-30 KT SWRLY LLJ
HAS ALLOWED FOR AN AREA SHOWERS/THUNDERSTORMS TO MOVE NNE ACROSS THE
AREA. THE HRRR HAS HAD A GOOD HANDEL ON THIS ACTIVITY
OVERNIGHT...AND FOLLOWED IT FAIRLY CLOSELY TO TIME THIS MORNINGS
BATCH OF ACTIVITY THROUGH THE AREA. THIS BATCH OF RAIN LOOKS TO BE
MOSTLY NORTH OF THE MPX AREA BY 15Z...WITH A BRIEF BREAK IN PRECIP
EXPECTED UNTIL THUNDERSTORMS GET GOING AGAIN LATER IN THE AFTERNOON.
FOR THE AFTERNOON...WE WILL BE DEALING WITH A RATHER MESSY SFC
PATTERN AS THE MESO LOW CURRENTLY NEAR SIOUX FALLS WASHES OUT OVER
MN AS IT GETS ABSORBED BY THE MAIN COLD FRONT...WHICH WAS STILL BACK
ACROSS WRN NODAK. BIGGEST CHANGE SEEN FROM THE 28.12 TO THE 29.00
MODEL RUNS WAS A WHOLESALE SLOWING OF THE FRONT/SFC TROUGH ACROSS
THE AREA. THIS HAS RESULTED IN HIGHER POPS BEING PUSHED BACK WEST
THIS AFTERNOON...AS WHAT WAS LOOKING LIKE WAS MAINLY GOING TO BE A
SHOW FOR AREAS ALONG/EAST OF I-35 IS NOW MORE OF AN ALONG/EAST OF A
ST. CLOUD TO FAIRMONT LINE. THE HI-RES MODELS THAT LOOK TO ADHERE
TO WHAT IS SEEN FORCING WISE WITH THE DETERMINISTIC MODELS THE BEST
ARE THE 29.00 NMM AND MPX WRFS...WHICH BOTH SHOW STORMS FORMING WEST
OF THE TWIN CITIES BETWEEN 19-21Z AND MOVING EAST FROM THERE AS A
BROKEN LINE OF STORMS. ONE THING THAT HAS NOT CHANGED...IS THE MOST
WIDESPREAD RAIN/HIGHEST AMOUNTS LOOK TO FALL ACROSS SE MN/WRN WI AS
THE AFTERNOON ACTIVITY TO THE WEST OF I-35 CONGEALS INTO A BROADER
MASS EAST OF I-35.
STILL NOT ANTICIPATING MUCH IN THE WAY OF SEVERE WEATHER TODAY
EITHER...AS CLOUD COVER LOOKS TO BE EXTENSIVE...WHICH WILL LIMIT THE
DEGREE OF DESTABILIZATION WE SEE BY THE AFTERNOON. IN ADDITION...MID
LEVEL LAPSE RATES WILL REMAIN RATHER WEAK...FURTHER POINTING TO
INSTABILITY SOMEWHAT LACKING WHEN IT COMES TO THE SEVERE WEATHER
POTENTIAL. BESIDE THE INSTABILITY...THE SFC PATTERN LOOKS TO BE
RATHER DIFFUSE...WITH NO CLEAR FOCUS EXISTING FOR THUNDERSTORM
ACTIVITY /SEE FRONT SUNDAY FOR A CLEAR FOCUS FOR THUNDERSTORM
DEVELOPMENT/. WITH THAT SAID...BULK SHEAR WILL BE UP IN THE 30-40 KT
RANGE AHEAD OF THE SFC TROUGH...SUFFICIENT ENOUGH TO ALLOW FOR A
MULTI-CELL CLUSTER OR TWO TO PULSE UP ENOUGH TO POSE AN ISOLATED
WIND/HAIL THREAT TODAY.
FOR HIGHS TODAY...THERE IS ADMITTEDLY SOME BUST POTENTIAL WITH THE
CURRENT FORECAST OF HIGHS IN THE 70S AS THAT IS PREDICATED ON CLOUD
COVER BEING DOMINATE TODAY. IF WE INSTEAD GET SOME DECENT SUN BEFORE
STORMS DEVELOP THIS AFTERNOON...THEN HIGHS IN THE LOWER/MID 80S WILL
BE MORE COMMON.
FOR TONIGHT...SHOWER AND THUNDERSTORM ACTIVITY LOOKS SLOWLY CLEAR
OUT TO THE EAST...WITH TO MUCH LEFT OUTSIDE OF SOME DRIZZLE IN WRN
WI BY 12Z SATURDAY. HOWEVER...THE SFC THROUGH/FRONT WILL BE VERY
SLOW IN WORKING ACROSS THE AREA...WITH PLENTIFUL LOW LEVEL MOISTURE
LOOKING TO HANG AROUND MOST OF THE NIGHT. THIS SHOULD ALLOW FOR
ANOTHER ROUND OF LOW STRATUS AND FOG TO EXPAND ACROSS THE AREA
TONIGHT...WHICH IN TURN WILL HELP KEEP LOWS UP MAINLY IN THE
MID/UPPER 60S.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 338 AM CDT FRI AUG 29 2014
THE MAIN STORY IN THE EXTENDED IS THE SYSTEM EXPECTED SUNDAY
AFTERNOON AND SUNDAY NIGHT WITH THE HIGH LIKELIHOOD OF WIDESPREAD
THUNDERSTORMS AND THE POTENTIAL FOR SEVERE WEATHER. THE RAIN
SHOULD CLEAR EARLY ON LABOR DAY...LEAVING MAINLY DRY WEATHER
ACROSS THE FORECAST AREA THROUGH AT LEAST MID WEEK.
THE TROUGH EXPECTED TO MOVE ACROSS THE NORTHERN CONUS SUN-MON AND
BRING WIDESPREAD THUNDERSTORMS TO THE NATION`S MID SECTION IS
ALREADY AN ESTABLISHED CIRCULATION WITH A WELL-DEFINED PV FEATURE
IN THE GULF OF ALASKA THIS MORNING. THE TROUGH WILL DIG SOUTHEAST
OVER THE NEXT 48 HOURS AND DEVELOP MORE OF A NEGATIVE TILT BEFORE
LIFTING NORTH TOWARD HUDSON BAY MONDAY NIGHT. THE JET STRUCTURE
SUPPORTS WIDESPREAD UPPER DIVERGENCE AND 500MB 12-HR HEIGHT FALLS
BETWEEN 80-100M SLIP ACROSS NORTHERN MN SUNDAY NIGHT. LOWER IN THE
ATMOSPHERE...850-700MB FGEN INCREASES IN WESTERN MN NEAR OR JUST
AFTER 18Z ON SUNDAY. THE BOUNDARY MAKES GRADUAL PROGRESS TO THE
EAST FROM 18Z SUNDAY UNTIL 12Z MONDAY. A SLOWLY DEEPENING AND
EASTWARD-MOVING SURFACE CYCLONE PRODUCES 4-6MB 6-HR MSLP PRESSURE
FALLS ACROSS THE FORECAST AREA ON SUNDAY. CONVECTIVE INITIATION
SHOULD NOT BE A PROBLEM...IN FACT...STORMS SHOULD ALREADY BE
ONGOING IN THE EASTERN DAKOTAS SATURDAY MORNING. ELEVATED
CONVECTION SHOULD TRANSITION TO MORE SURFACE BASED CONVECTION WITH
HEATING AND THE LIKELY ESTABLISHMENT OF LARGE LINE SEGMENTS OR
CLUSTERS OF THUNDERSTORMS DUE TO THE LARGE-SCALE FORCING. THE DEEP
LAYER SHEAR SHOULD BE GOOD ENOUGH TO ORGANIZE STORMS INTO MULTI-CELL
WITH EMBEDDED SUPERCELLS /EVEN IF THEY EXIST IN LINES/. THE
INSTABILITY SHOULD BE SUFFICIENT TO SUPPORT STRONG UPDRAFTS. IT
LOOKS PRIMARILY LIKE A WIND AND HAIL THREAT IN THE AFTERNOON AND
EVENING HOURS ACROSS MN. BOTH THE NAM AND GFS HAVE 0-3KM SHEAR ON
THE ORDER OF 25-40KTS FROM 18Z-06Z ACROSS THE FORECAST AREA. THE
SEVERE THREAT DIMINISHES IN WI GIVEN THE LOSS OF INSTABILITY
SUNDAY NIGHT AND QUICKLY NORTHWARD LIFTING SURFACE LOW. BEYOND THE
WEEKEND...THE TROUGH FLATTENS OUT AND WE`RE LEFT WITH A RELATIVELY
DRY AND COOL WESTERLY FLOW PATTERN THROUGH AT LEAST MID WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1153 AM CDT FRI AUG 29 2014
TWO AREAS OF CONVECTION ACROSS THE PLAINS AND UPPER MIDWEST WILL
LEAD TO OCCASIONAL SHRA/TSRA FOR MOST OF MPX TAF AREA THRU THE AFTN
WITH THE EXCEPTION OF KAXN WHERE THE SFC TROUGH HAS MOVED THRU AS
OF 17Z. AN UPPER LOW WHICH IS CURRENTLY NEAR KOMA WILL LIKELY HOLD
THE SFC TROUGH ACROSS CENTRAL MN THIS AFTN AS THE UPPER LOW MOVES
NE ACROSS NC IA/SE MN. THIS WILL LEAD TO THE CONTINUATION OF
SHRA/TSRA FROM KRWF TO KSTC...EASTWARD TOWARD EC MN/WC WI THRU
THE AFTN. TIMING OF HEAVIER TSRA WILL BE PROBLEMATIC SO WILL
CONTINUE WITH TEMPO PERIOD FOR MOST AREAS WITH 2SM +TSRA. ALTHOUGH
VSBYS WILL BE REDUCED TO LESS THAN 1SM AT TIMES...IT SHOULD BE
VERY SHORT AND LAST 5 TO 10 MINS. MORE MODERATE SHRA/TSRA WILL
MEAN PERIODS OF 2-3SM WITH A PREDOMINATE 4-6SM IN LIGHTER
ACTIVITY. MOST OF THE SHRA/TSRA SHOULD MOVE OFF INTO WC WI BY
23-01Z...WITH IFR/LIFR CIGS/VSBYS DEVELOPING IN THE WAKE OF THIS
SYSTEM. WINDS WILL BE FROM THE S/SW AHEAD OF THE SFC
TROUGH...WITH A WEAK WEST/NW FLOW BEHIND IT THRU THIS EVENING. A
MORE NW/NNW IS EXPECTED BY SATURDAY MORNING ARND 5-10 KTS.
KMSP...
TWO AREAS OF CONVECTION WILL LEAD TO A CONTINUED TREND OF SHRA AND
EMBEDDED TSRA THRU THE AFTN. NOT UNTIL THE SFC TROUGH MOVES EAST
OF THE AREA ALONG WITH THE UPPER LOW...WILL CHC/S OF SHRA/TSRA
DIMINISH. TIMING OF THE HEAVIER TSRA REMAINS QUESTIONABLE...SO
WILL CONTINUE WITH A TEMPO OF 2SM +TSRA DURING THE AFTN. A BRIEF
PERIOD OF VSBYS LESS THAN 1SM IS LIKELY...BUT SHOULD ONLY LAST 5
TO 10 MINS. MOST OF THE STEADIER SHRA SHOULD MOVE OUT OF MSP
TERMINAL AREA BY 1-3Z WITH IFR/LIFR CIGS/VSBYS DEVELOPING
OVERNIGHT. VFR CONDS ARE NOT EXPECTED UNTIL AFT 18Z ON SATURDAY.
WINDS WILL BE GENERALLY FROM THE SW THIS AFTN ARND 5-10 KTS...THEN
WEAKEN AND VEER WEST TO NORTHWEST OVERNIGHT.
/OUTLOOK FOR KMSP/
SAT AFTN...VFR. WIND NNE AT 5-10 KTS.
SUN...VFR WITH MVFR/TSRA LATE. WINDS SSE AT 10-20 KTS.
MON...MVFR/TSRA ENDING EARLY. VFR BY AFTN WINDS W 10-15KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...CLF
AVIATION...JLT
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
614 AM CDT FRI AUG 29 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 338 AM CDT FRI AUG 29 2014
RATHER UGLY MORNING OUT THERE IN TERMS OF AVIATION...WITH PLENTIFUL
AMOUNTS OF LOW CIGS AND FOG OUT AHEAD OF A WARM FRONT THAT WAS
STARTING TO MAKE PROGRESS NORTH INTO MN AND AT 3 AM WAS NEAR THE
I-90 CORRIDOR. BESIDE THE LOW CLOUDS...ISENTROPIC LIFT AND ELEVATED
INSTABILITY ADVECTION ASSOCIATED WITH A MODEST 20-30 KT SWRLY LLJ
HAS ALLOWED FOR AN AREA SHOWERS/THUNDERSTORMS TO MOVE NNE ACROSS THE
AREA. THE HRRR HAS HAD A GOOD HANDEL ON THIS ACTIVITY
OVERNIGHT...AND FOLLOWED IT FAIRLY CLOSELY TO TIME THIS MORNINGS
BATCH OF ACTIVITY THROUGH THE AREA. THIS BATCH OF RAIN LOOKS TO BE
MOSTLY NORTH OF THE MPX AREA BY 15Z...WITH A BRIEF BREAK IN PRECIP
EXPECTED UNTIL THUNDERSTORMS GET GOING AGAIN LATER IN THE AFTERNOON.
FOR THE AFTERNOON...WE WILL BE DEALING WITH A RATHER MESSY SFC
PATTERN AS THE MESO LOW CURRENTLY NEAR SIOUX FALLS WASHES OUT OVER
MN AS IT GETS ABSORBED BY THE MAIN COLD FRONT...WHICH WAS STILL BACK
ACROSS WRN NODAK. BIGGEST CHANGE SEEN FROM THE 28.12 TO THE 29.00
MODEL RUNS WAS A WHOLESALE SLOWING OF THE FRONT/SFC TROUGH ACROSS
THE AREA. THIS HAS RESULTED IN HIGHER POPS BEING PUSHED BACK WEST
THIS AFTERNOON...AS WHAT WAS LOOKING LIKE WAS MAINLY GOING TO BE A
SHOW FOR AREAS ALONG/EAST OF I-35 IS NOW MORE OF AN ALONG/EAST OF A
ST. CLOUD TO FAIRMONT LINE. THE HI-RES MODELS THAT LOOK TO ADHERE
TO WHAT IS SEEN FORCING WISE WITH THE DETERMINISTIC MODELS THE BEST
ARE THE 29.00 NMM AND MPX WRFS...WHICH BOTH SHOW STORMS FORMING WEST
OF THE TWIN CITIES BETWEEN 19-21Z AND MOVING EAST FROM THERE AS A
BROKEN LINE OF STORMS. ONE THING THAT HAS NOT CHANGED...IS THE MOST
WIDESPREAD RAIN/HIGHEST AMOUNTS LOOK TO FALL ACROSS SE MN/WRN WI AS
THE AFTERNOON ACTIVITY TO THE WEST OF I-35 CONGEALS INTO A BROADER
MASS EAST OF I-35.
STILL NOT ANTICIPATING MUCH IN THE WAY OF SEVERE WEATHER TODAY
EITHER...AS CLOUD COVER LOOKS TO BE EXTENSIVE...WHICH WILL LIMIT THE
DEGREE OF DESTABILIZATION WE SEE BY THE AFTERNOON. IN ADDITION...MID
LEVEL LAPSE RATES WILL REMAIN RATHER WEAK...FURTHER POINTING TO
INSTABILITY SOMEWHAT LACKING WHEN IT COMES TO THE SEVERE WEATHER
POTENTIAL. BESIDE THE INSTABILITY...THE SFC PATTERN LOOKS TO BE
RATHER DIFFUSE...WITH NO CLEAR FOCUS EXISTING FOR THUNDERSTORM
ACTIVITY /SEE FRONT SUNDAY FOR A CLEAR FOCUS FOR THUNDERSTORM
DEVELOPMENT/. WITH THAT SAID...BULK SHEAR WILL BE UP IN THE 30-40 KT
RANGE AHEAD OF THE SFC TROUGH...SUFFICIENT ENOUGH TO ALLOW FOR A
MULTI-CELL CLUSTER OR TWO TO PULSE UP ENOUGH TO POSE AN ISOLATED
WIND/HAIL THREAT TODAY.
FOR HIGHS TODAY...THERE IS ADMITTEDLY SOME BUST POTENTIAL WITH THE
CURRENT FORECAST OF HIGHS IN THE 70S AS THAT IS PREDICATED ON CLOUD
COVER BEING DOMINATE TODAY. IF WE INSTEAD GET SOME DECENT SUN BEFORE
STORMS DEVELOP THIS AFTERNOON...THEN HIGHS IN THE LOWER/MID 80S WILL
BE MORE COMMON.
FOR TONIGHT...SHOWER AND THUNDERSTORM ACTIVITY LOOKS SLOWLY CLEAR
OUT TO THE EAST...WITH TO MUCH LEFT OUTSIDE OF SOME DRIZZLE IN WRN
WI BY 12Z SATURDAY. HOWEVER...THE SFC THROUGH/FRONT WILL BE VERY
SLOW IN WORKING ACROSS THE AREA...WITH PLENTIFUL LOW LEVEL MOISTURE
LOOKING TO HANG AROUND MOST OF THE NIGHT. THIS SHOULD ALLOW FOR
ANOTHER ROUND OF LOW STRATUS AND FOG TO EXPAND ACROSS THE AREA
TONIGHT...WHICH IN TURN WILL HELP KEEP LOWS UP MAINLY IN THE
MID/UPPER 60S.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 338 AM CDT FRI AUG 29 2014
THE MAIN STORY IN THE EXTENDED IS THE SYSTEM EXPECTED SUNDAY
AFTERNOON AND SUNDAY NIGHT WITH THE HIGH LIKELIHOOD OF WIDESPREAD
THUNDERSTORMS AND THE POTENTIAL FOR SEVERE WEATHER. THE RAIN
SHOULD CLEAR EARLY ON LABOR DAY...LEAVING MAINLY DRY WEATHER
ACROSS THE FORECAST AREA THROUGH AT LEAST MID WEEK.
THE TROUGH EXPECTED TO MOVE ACROSS THE NORTHERN CONUS SUN-MON AND
BRING WIDESPREAD THUNDERSTORMS TO THE NATION`S MID SECTION IS
ALREADY AN ESTABLISHED CIRCULATION WITH A WELL-DEFINED PV FEATURE
IN THE GULF OF ALASKA THIS MORNING. THE TROUGH WILL DIG SOUTHEAST
OVER THE NEXT 48 HOURS AND DEVELOP MORE OF A NEGATIVE TILT BEFORE
LIFTING NORTH TOWARD HUDSON BAY MONDAY NIGHT. THE JET STRUCTURE
SUPPORTS WIDESPREAD UPPER DIVERGENCE AND 500MB 12-HR HEIGHT FALLS
BETWEEN 80-100M SLIP ACROSS NORTHERN MN SUNDAY NIGHT. LOWER IN THE
ATMOSPHERE...850-700MB FGEN INCREASES IN WESTERN MN NEAR OR JUST
AFTER 18Z ON SUNDAY. THE BOUNDARY MAKES GRADUAL PROGRESS TO THE
EAST FROM 18Z SUNDAY UNTIL 12Z MONDAY. A SLOWLY DEEPENING AND
EASTWARD-MOVING SURFACE CYCLONE PRODUCES 4-6MB 6-HR MSLP PRESSURE
FALLS ACROSS THE FORECAST AREA ON SUNDAY. CONVECTIVE INITIATION
SHOULD NOT BE A PROBLEM...IN FACT...STORMS SHOULD ALREADY BE
ONGOING IN THE EASTERN DAKOTAS SATURDAY MORNING. ELEVATED
CONVECTION SHOULD TRANSITION TO MORE SURFACE BASED CONVECTION WITH
HEATING AND THE LIKELY ESTABLISHMENT OF LARGE LINE SEGMENTS OR
CLUSTERS OF THUNDERSTORMS DUE TO THE LARGE-SCALE FORCING. THE DEEP
LAYER SHEAR SHOULD BE GOOD ENOUGH TO ORGANIZE STORMS INTO MULTI-CELL
WITH EMBEDDED SUPERCELLS /EVEN IF THEY EXIST IN LINES/. THE
INSTABILITY SHOULD BE SUFFICIENT TO SUPPORT STRONG UPDRAFTS. IT
LOOKS PRIMARILY LIKE A WIND AND HAIL THREAT IN THE AFTERNOON AND
EVENING HOURS ACROSS MN. BOTH THE NAM AND GFS HAVE 0-3KM SHEAR ON
THE ORDER OF 25-40KTS FROM 18Z-06Z ACROSS THE FORECAST AREA. THE
SEVERE THREAT DIMINISHES IN WI GIVEN THE LOSS OF INSTABILITY
SUNDAY NIGHT AND QUICKLY NORTHWARD LIFTING SURFACE LOW. BEYOND THE
WEEKEND...THE TROUGH FLATTENS OUT AND WE`RE LEFT WITH A RELATIVELY
DRY AND COOL WESTERLY FLOW PATTERN THROUGH AT LEAST MID WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 557 AM CDT FRI AUG 29 2014
THE RAP CAUGHT ON TO THE VFR CONDITIONS MOVING NORTH OUT OF
SOUTHERN MN PRETTY QUICK THIS MORNING...AND FOLLOWED IT/S IDEA FOR
BRINGING VFR CONDITIONS UP INTO ERN MN/WRN WI. WITH THE SFC LOW
MOVING INTO SW MN...WILL TAKE A BIT LONGER FOR AXN TO SEE
IMPROVEMENTS. FOR TSRA THIS AFTERNOON...FOLLOWED THE TRENDS OF
HRRR/MPXWRF/NMMWRF...WHICH ARE ALL PRETTY SIMILAR WITH THEIR
HANDLING OF TSRA THIS AFTERNOON/EVENING. STORMS LOOK TO DEVELOP
BETWEEN 18Z AND 20Z NEAR/EAST OF A RWF TO STC LINE AND MOVE EAST
FROM THERE. BEHIND THE AFTERNOON STORMS...THE PRESSURE GRADIENT
LOOKS WEAK...WITH THE MAIN COLD FRONT AND ITS DRY AIR STILL HUNG
UP NORTHWEST OF THE MPX CWA. THIS MEANS WE WILL HAVE ANOTHER NIGHT
WITH VLIFR/LIFR CIGS. GIVEN LOW LEVEL WINDS...STRATUS IS MOST
LIKELY IN MN...BUT WINDS WILL BE LIGHT ENOUGH IN WRN WI TO LEAD TO
HEIGHTENED THREAT FOR FOG AT RNH/EAU.
KMSP...VFR CONDITIONS MOVING UP FROM THE SOUTH LOOK TO BE HERE TO
STAY FOR THE REST OF THE MORNING GIVEN THE FACT WE HAVE NOT SEEN
CIGS FILL BACK IN ACROSS SRN MN/NRN IA...SO WILL KEEP CIGS VFR
UNTIL TONIGHT. FRONTAL BOUNDARY FOR THE AFTERNOON IS LOOKING
SLOWER IN GETTING HERE...ALLOWING CONFIDENCE TO BE QUITE HIGH IN
MSP SEEING ANOTHER ROUND OF TSRA THIS AFTERNOON. TONIGHT...AGAIN
THERE IS HIGH CONFIDENCE IN ANOTHER ROUND OF IFR STRATUS...JUST A
QUESTION OF HOW QUICKLY DOES IT COME IN AND HOW LOW DOES IT GO.
/OUTLOOK FOR KMSP/
SAT...VFR. WIND NNE AT 5-10 KTS.
SUN...VFR WITH MVFR/TSRA LATE. WINDS SSE AT 10-20 KTS.
MON...MVFR/TSRA ENDING EARLY. VFR BY AFTNOON WINDS W 10-15KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...CLF
AVIATION...MPG
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
431 AM CDT FRI AUG 29 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 338 AM CDT FRI AUG 29 2014
RATHER UGLY MORNING OUT THERE IN TERMS OF AVIATION...WITH PLENTIFUL
AMOUNTS OF LOW CIGS AND FOG OUT AHEAD OF A WARM FRONT THAT WAS
STARTING TO MAKE PROGRESS NORTH INTO MN AND AT 3 AM WAS NEAR THE
I-90 CORRIDOR. BESIDE THE LOW CLOUDS...ISENTROPIC LIFT AND ELEVATED
INSTABILITY ADVECTION ASSOCIATED WITH A MODEST 20-30 KT SWRLY LLJ
HAS ALLOWED FOR AN AREA SHOWERS/THUNDERSTORMS TO MOVE NNE ACROSS THE
AREA. THE HRRR HAS HAD A GOOD HANDEL ON THIS ACTIVITY
OVERNIGHT...AND FOLLOWED IT FAIRLY CLOSELY TO TIME THIS MORNINGS
BATCH OF ACTIVITY THROUGH THE AREA. THIS BATCH OF RAIN LOOKS TO BE
MOSTLY NORTH OF THE MPX AREA BY 15Z...WITH A BRIEF BREAK IN PRECIP
EXPECTED UNTIL THUNDERSTORMS GET GOING AGAIN LATER IN THE AFTERNOON.
FOR THE AFTERNOON...WE WILL BE DEALING WITH A RATHER MESSY SFC
PATTERN AS THE MESO LOW CURRENTLY NEAR SIOUX FALLS WASHES OUT OVER
MN AS IT GETS ABSORBED BY THE MAIN COLD FRONT...WHICH WAS STILL BACK
ACROSS WRN NODAK. BIGGEST CHANGE SEEN FROM THE 28.12 TO THE 29.00
MODEL RUNS WAS A WHOLESALE SLOWING OF THE FRONT/SFC TROUGH ACROSS
THE AREA. THIS HAS RESULTED IN HIGHER POPS BEING PUSHED BACK WEST
THIS AFTERNOON...AS WHAT WAS LOOKING LIKE WAS MAINLY GOING TO BE A
SHOW FOR AREAS ALONG/EAST OF I-35 IS NOW MORE OF AN ALONG/EAST OF A
ST. CLOUD TO FAIRMONT LINE. THE HI-RES MODELS THAT LOOK TO ADHERE
TO WHAT IS SEEN FORCING WISE WITH THE DETERMINISTIC MODELS THE BEST
ARE THE 29.00 NMM AND MPX WRFS...WHICH BOTH SHOW STORMS FORMING WEST
OF THE TWIN CITIES BETWEEN 19-21Z AND MOVING EAST FROM THERE AS A
BROKEN LINE OF STORMS. ONE THING THAT HAS NOT CHANGED...IS THE MOST
WIDESPREAD RAIN/HIGHEST AMOUNTS LOOK TO FALL ACROSS SE MN/WRN WI AS
THE AFTERNOON ACTIVITY TO THE WEST OF I-35 CONGEALS INTO A BROADER
MASS EAST OF I-35.
STILL NOT ANTICIPATING MUCH IN THE WAY OF SEVERE WEATHER TODAY
EITHER...AS CLOUD COVER LOOKS TO BE EXTENSIVE...WHICH WILL LIMIT THE
DEGREE OF DESTABILIZATION WE SEE BY THE AFTERNOON. IN ADDITION...MID
LEVEL LAPSE RATES WILL REMAIN RATHER WEAK...FURTHER POINTING TO
INSTABILITY SOMEWHAT LACKING WHEN IT COMES TO THE SEVERE WEATHER
POTENTIAL. BESIDE THE INSTABILITY...THE SFC PATTERN LOOKS TO BE
RATHER DIFFUSE...WITH NO CLEAR FOCUS EXISTING FOR THUNDERSTORM
ACTIVITY /SEE FRONT SUNDAY FOR A CLEAR FOCUS FOR THUNDERSTORM
DEVELOPMENT/. WITH THAT SAID...BULK SHEAR WILL BE UP IN THE 30-40 KT
RANGE AHEAD OF THE SFC TROUGH...SUFFICIENT ENOUGH TO ALLOW FOR A
MULTI-CELL CLUSTER OR TWO TO PULSE UP ENOUGH TO POSE AN ISOLATED
WIND/HAIL THREAT TODAY.
FOR HIGHS TODAY...THERE IS ADMITTEDLY SOME BUST POTENTIAL WITH THE
CURRENT FORECAST OF HIGHS IN THE 70S AS THAT IS PREDICATED ON CLOUD
COVER BEING DOMINATE TODAY. IF WE INSTEAD GET SOME DECENT SUN BEFORE
STORMS DEVELOP THIS AFTERNOON...THEN HIGHS IN THE LOWER/MID 80S WILL
BE MORE COMMON.
FOR TONIGHT...SHOWER AND THUNDERSTORM ACTIVITY LOOKS SLOWLY CLEAR
OUT TO THE EAST...WITH TO MUCH LEFT OUTSIDE OF SOME DRIZZLE IN WRN
WI BY 12Z SATURDAY. HOWEVER...THE SFC THROUGH/FRONT WILL BE VERY
SLOW IN WORKING ACROSS THE AREA...WITH PLENTIFUL LOW LEVEL MOISTURE
LOOKING TO HANG AROUND MOST OF THE NIGHT. THIS SHOULD ALLOW FOR
ANOTHER ROUND OF LOW STRATUS AND FOG TO EXPAND ACROSS THE AREA
TONIGHT...WHICH IN TURN WILL HELP KEEP LOWS UP MAINLY IN THE
MID/UPPER 60S.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 338 AM CDT FRI AUG 29 2014
THE MAIN STORY IN THE EXTENDED IS THE SYSTEM EXPECTED SUNDAY
AFTERNOON AND SUNDAY NIGHT WITH THE HIGH LIKELIHOOD OF WIDESPREAD
THUNDERSTORMS AND THE POTENTIAL FOR SEVERE WEATHER. THE RAIN
SHOULD CLEAR EARLY ON LABOR DAY...LEAVING MAINLY DRY WEATHER
ACROSS THE FORECAST AREA THROUGH AT LEAST MID WEEK.
THE TROUGH EXPECTED TO MOVE ACROSS THE NORTHERN CONUS SUN-MON AND
BRING WIDESPREAD THUNDERSTORMS TO THE NATION`S MID SECTION IS
ALREADY AN ESTABLISHED CIRCULATION WITH A WELL-DEFINED PV FEATURE
IN THE GULF OF ALASKA THIS MORNING. THE TROUGH WILL DIG SOUTHEAST
OVER THE NEXT 48 HOURS AND DEVELOP MORE OF A NEGATIVE TILT BEFORE
LIFTING NORTH TOWARD HUDSON BAY MONDAY NIGHT. THE JET STRUCTURE
SUPPORTS WIDESPREAD UPPER DIVERGENCE AND 500MB 12-HR HEIGHT FALLS
BETWEEN 80-100M SLIP ACROSS NORTHERN MN SUNDAY NIGHT. LOWER IN THE
ATMOSPHERE...850-700MB FGEN INCREASES IN WESTERN MN NEAR OR JUST
AFTER 18Z ON SUNDAY. THE BOUNDARY MAKES GRADUAL PROGRESS TO THE
EAST FROM 18Z SUNDAY UNTIL 12Z MONDAY. A SLOWLY DEEPENING AND
EASTWARD-MOVING SURFACE CYCLONE PRODUCES 4-6MB 6-HR MSLP PRESSURE
FALLS ACROSS THE FORECAST AREA ON SUNDAY. CONVECTIVE INITIATION
SHOULD NOT BE A PROBLEM...IN FACT...STORMS SHOULD ALREADY BE
ONGOING IN THE EASTERN DAKOTAS SATURDAY MORNING. ELEVATED
CONVECTION SHOULD TRANSITION TO MORE SURFACE BASED CONVECTION WITH
HEATING AND THE LIKELY ESTABLISHMENT OF LARGE LINE SEGMENTS OR
CLUSTERS OF THUNDERSTORMS DUE TO THE LARGE-SCALE FORCING. THE DEEP
LAYER SHEAR SHOULD BE GOOD ENOUGH TO ORGANIZE STORMS INTO MULTCELL
WITH EMBEDDED SUPERCELLS /EVEN IF THEY EXIST IN LINES/. THE
INSTABILITY SHOULD BE SUFFICIENT TO SUPPORT STRONG UPDRAFTS. IT
LOOKS PRIMARILY LIKE A WIND AND HAIL THREAT IN THE AFTERNOON AND
EVENING HOURS ACROSS MN. BOTH THE NAM AND GFS HAVE 0-3KM SHEAR ON
THE ORDER OF 25-40KTS FROM 18Z-06Z ACROSS THE FORECAST AREA. THE
SEVERE THREAT DIMINISHES IN WI GIVEN THE LOSS OF INSTABILITY
SUNDAY NIGHT AND QUICKLY NORTHWARD LIFTING SURFACE LOW. BEYOND THE
WEEKEND...THE TROUGH FLATTENS OUT AND WE`RE LEFT WITH A RELATIVELY
DRY AND COOL WESTERLY FLOW PATTERN THROUGH AT LEAST MID WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1155 PM CDT THU AUG 28 2014
IFR OR LIFR CONDITIONS WILL PERSIST THROUGH THE OVERNIGHT AND INTO
AT LEAST MID MORNING FRIDAY...WITH THE WORST CONDITIONS ACROSS
SOUTHERN AND WESTERN MINNESOTA. MODELS SHOW A SOMEWHAT RAPID
IMPROVEMENT BY LATE MORNING...BUT AM A BIT SKEPTICAL GIVEN THE
AMPLE LOW LEVEL MOISTURE IN PLACE. WILL NEED TO WATCH TRENDS
OVERNIGHT. SCATTERED SHOWERS WILL ALSO CONTINUE TONIGHT...BECOMING
A BIT MORE WIDESPREAD ACROSS ERN MN AND WRN WI FRIDAY AFTERNOON.
KMSP...CIGS HAVE HAD A HARD TIME MAINTAINING IFR STATUS THIS
EVENING...BUT SURROUNDING OBS CONTINUE TO DETERIORATE AND BELIEVE
IT WON/T BE TOO MUCH LONGER THAT MSP WILL FINALLY JOIN THE IFR
CLUB. IMPROVEMENTS ARE CURRENTLY FORECAST BY LATE MORNING...BUT AS
ALLUDED TO ABOVE THIS MAY BE A BIT TOO OPTIMISTIC.
/OUTLOOK FOR KMSP/
SAT...VFR. WIND NNE AT 5-10 KTS.
SUN...VFR WITH MVFR/TSRA LATE. WINDS SSE AT 10KTS.
MON...VFR WITH MVFR/TSRA EARLY. WINDS W 10-15KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...CLF
AVIATION...BORGHOFF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
1102 PM CDT SAT AUG 30 2014
.UPDATE...ANOTHER UPDATE TO LOWER POPS QUITE A BIT FOR THE REMAINDER
OF THE NIGHT AND REMOVE MOST MENTIONS OF THUNDER. DUE TO THE CURRENT
TRENDS...ONLY EXPECT ISOLATED SHRA ACTIVITY AT BEST UNTIL 2 AM OR SO.
THERE LOOKS TO BE SOME POTENTIAL FOR AN INCREASE IN ACTIVITY ACROSS
THE NW/N-CENTRAL AREAS AFTER 2 AM. DUE TO THIS...WILL BOOST POPS BACK
TO 40-50% ACROSS THOSE AREAS. /CME/
&&
.PREV DISCUSSION... /ISSUED 911 PM CDT SAT AUG 30 2014/
UPDATE...THE CWA REMAINS IN A RELATIVE LULL IN PRECIPITATION THIS
EVENING...THOUGH SHOWERS HAVE BEEN PERSISTING OVER PORTIONS OF SE
ARKANSAS AND THE MS DELTA. SURFACE OBSERVATIONS AND REGIONAL RADAR
COMPOSITES SHOW A MESOLOW OVER SOUTHERN ARKANSAS ASSOCIATED WITH THE
CONTINUED SHOWERS IN THAT AREA. IN ADDITION...THERE IS A LARGE
CLUSTER OF CONVECTION ALONG THE LA COAST...WITH SHOWERS EXTENDING
NORTHWARD INTO SW MISSISSIPPI ALONG A CORRIDOR OF MOISTURE-RICH AIR.
00Z KJAN RAOB WHICH WENT UP AFTER THE BRUNT OF THE AFTERNOON
THUNDERSTORM ACTIVITY STILL SAMPLED A 2.2 INCH PWAT. LARGER SCALE
MODELS SHOW THIS N-S AXIS OF DEEP LAYER MOISTURE REMAINING ACROSS
THE CWA OVERNIGHT...MAKING ADDITIONAL SHOWER AND THUNDERSTORM
DEVELOPMENT QUITE POSSIBLE. THIS IS SUPPORTED BY THE HRRR WHICH
DEPICTS REDEVELOPMENT OF SHOWERS AND A FEW STORMS OVERNIGHT. NO NEW
ADJUSTMENTS ARE PLANNED FOR POPS/WX AT THIS TIME...BUT HOURLY
TEMPS/DEWPOINTS WILL BE TWEAKED TO ACCOUNT FOR CURRENT OBSERVATIONAL
TRENDS. /DL/
&&
.AVIATION...
WIDESPREAD MVFR TO LOCALLY IFR CONDITIONS ARE EXPECTED
TO BUILD OVER THE REGION AS THE NIGHT GOES ON...MAINLY DUE TO LOW
CEILINGS. THE BEST CHANCE FOR FOG DETRIMENTAL TO OPERATIONS WILL BE
AT PIB/HBG TOWARDS DAWN. ONLY PATCHY LIGHT RAIN IS AROUND THE REGION
THIS EVENING ALTHOUGH SOME SPOTTY HEAVIER DOWNPOURS AND MAYBE EVEN A
FEW THUNDERSTORMS ARE POSSIBLE LATER TONIGHT. PRECIPITATION SHOULD
BE MORE ISOLATED TOMORROW WITH WINDS FROM THE SOUTH RANGING UP TO 15
KTS AT TIMES. CONDITIONS SHOULD BE MAINLY VFR BY LATE MORNING. /BB/
DISCUSSION... /ISSUED AT 312 PM CDT SAT AUG 30 2014/
SHORT TERM...THROUGH MONDAY NIGHT...WHILE MID LEVEL RIDGING WILL
TAKE HOLD ACROSS THE LOWER CONUS THROUGH THE FIRST PART OF THE
WEEK...WEAK CYCLONIC SHEAR AXIS LOOKS TO REMAIN OVER THE ARKLAMISS
AT LEAST THROUGH MONDAY. THIS COMBINED WITH PW/S NEAR 2 INCHES WILL
CONTINUE TO ALLOW ISOLATED SHOWERS AND THUNDERSTORMS TO DEVELOP
ALONG WITH THE BUILDING HEAT. LOWER 90S PREVALENT SUNDAY WILL BE
REPLACED BY MID 90S MONDAY./26/
LONG TERM...TUESDAY THROUGH NEXT SATURDAY...NEAR TO SLIGHTLY ABOVE
NORMAL TEMPERATURES IN THE LOW TO MID 90S AND TYPICAL 20-30%
AFTERNOON CHANCES OF SHOWERS/STORMS THROUGH MOST OF THE WEEK AS A
HIGH PRESSURE RIDGE BUILDS OVER THE SE/CENTRAL CONUS.
DESPITE LOW-LVL HIGH PRESSURE AXIS AND SLOWLY BUILDING HEIGHT
INFLUENCE OVER REGION MOST OF THE WEEK, PWATS WILL REMAIN ELEVATED
/NEAR 2"/ AND COMBINED WITH DAILY AFTERNOON INSTABILITY /2000 J/KG+/,
ISOLATED/SCATTERED SHOWERS/STORMS WILL BE LIKELY. OVERALL COVERAGE
WONT BE GREAT BUT FEEL BEST COVERAGE WILL BE IN S/SE/E WHERE SEA-
BREEZE CONVERGENCE AND HIGHEST PWATS WILL EXIST. HEAT INDICES MONDAY
AND TUESDAY SHOULD REACH INTO THE LOW 100S FOR A FEW HOURS WITH LOWS
ONLY FALLING INTO THE LOW TO MID 70S THROUGH MUCH OF THE WEEK.
ON TUESDAY...A SLIGHTLY STRONGER S/WV TROUGH ACROSS THE CORN BELT
WILL ATTEMPT TO BRING A BOUNDARY SOUTH TOWARDS THE REGION BUT FEEL
IT STAY NORTH AND THUS KEPT POPS/SHOWERS OUT OF FORECAST FOR
NORTHERN AREAS. FOR WEDNESDAY THROUGH FRIDAY...RIDGING WILL REMAIN
OVER AREA AND STRENGTHEN SLIGHTLY BUT SEA-BREEZE INITIATED AND
DIURNAL ACTIVITY SHOULD CONTINUE TO BE A GOOD POSSIBILITY EACH DAY.
BY SATURDAY, THE RIDGING SLIPS FARTHER WEST AND PLACES REGION IN
SLIGHTLY GREATER N/NE FLOW THAT COULD ENHANCE SHOWER COVERAGE
POSSIBILITIES. /ALLEN/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 73 92 73 94 / 20 18 7 20
MERIDIAN 71 93 71 95 / 18 18 7 17
VICKSBURG 74 90 71 93 / 20 18 7 19
HATTIESBURG 74 95 74 95 / 23 18 13 19
NATCHEZ 72 90 73 91 / 20 18 12 27
GREENVILLE 73 90 72 94 / 47 18 6 10
GREENWOOD 73 91 72 95 / 37 21 6 10
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
CME
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
911 PM CDT SAT AUG 30 2014
.UPDATE...THE CWA REMAINS IN A RELATIVE LULL IN PRECIPITATION THIS
EVENING...THOUGH SHOWERS HAVE BEEN PERSISTING OVER PORTIONS OF SE
ARKANSAS AND THE MS DELTA. SURFACE OBSERVATIONS AND REGIONAL RADAR
COMPOSITES SHOW A MESOLOW OVER SOUTHERN ARKANSAS ASSOCIATED WITH THE
CONTINUED SHOWERS IN THAT AREA. IN ADDITION...THERE IS A LARGE
CLUSTER OF CONVECTION ALONG THE LA COAST...WITH SHOWERS EXTENDING
NORTHWARD INTO SW MISSISSIPPI ALONG A CORRIDOR OF MOISTURE-RICH AIR.
00Z KJAN RAOB WHICH WENT UP AFTER THE BRUNT OF THE AFTERNOON
THUNDERSTORM ACTIVITY STILL SAMPLED A 2.2 INCH PWAT. LARGER SCALE
MODELS SHOW THIS N-S AXIS OF DEEP LAYER MOISTURE REMAINING ACROSS
THE CWA OVERNIGHT...MAKING ADDITIONAL SHOWER AND THUNDERSTORM
DEVELOPMENT QUITE POSSIBLE. THIS IS SUPPORTED BY THE HRRR WHICH
DEPICTS REDEVELOPMENT OF SHOWERS AND A FEW STORMS OVERNIGHT. NO NEW
ADJUSTMENTS ARE PLANNED FOR POPS/WX AT THIS TIME...BUT HOURLY
TEMPS/DEWPOINTS WILL BE TWEAKED TO ACCOUNT FOR CURRENT OBSERVATIONAL
TRENDS. /DL/
&&
.AVIATION...WIDESPREAD MVFR TO LOCALLY IFR CONDITIONS ARE EXPECTED
TO BUILD OVER THE REGION AS THE NIGHT GOES ON...MAINLY DUE TO LOW
CEILINGS. THE BEST CHANCE FOR FOG DETRIMENTAL TO OPERATIONS WILL BE
AT PIB/HBG TOWARDS DAWN. ONLY PATCHY LIGHT RAIN IS AROUND THE REGION
THIS EVENING ALTHOUGH SOME SPOTTY HEAVIER DOWNPOURS AND MAYBE EVEN A
FEW THUNDERSTORMS ARE POSSIBLE LATER TONIGHT. PRECIPITATION SHOULD
BE MORE ISOLATED TOMORROW WITH WINDS FROM THE SOUTH RANGING UP TO 15
KTS AT TIMES. CONDITIONS SHOULD BE MAINLY VFR BY LATE MORNING. /BB/
&&
.DISCUSSION... /ISSUED AT 312 PM CDT SAT AUG 30 2014/
SHORT TERM...THROUGH MONDAY NIGHT...WHILE MID LEVEL RIDGING WILL
TAKE HOLD ACROSS THE LOWER CONUS THROUGH THE FIRST PART OF THE
WEEK...WEAK CYCLONIC SHEAR AXIS LOOKS TO REMAIN OVER THE ARKLAMISS
AT LEAST THROUGH MONDAY. THIS COMBINED WITH PW/S NEAR 2 INCHES WILL
CONTINUE TO ALLOW ISOLATED SHOWERS AND THUNDERSTORMS TO DEVELOP
ALONG WITH THE BUILDING HEAT. LOWER 90S PREVALENT SUNDAY WILL BE
REPLACED BY MID 90S MONDAY./26/
LONG TERM...TUESDAY THROUGH NEXT SATURDAY...NEAR TO SLIGHTLY ABOVE
NORMAL TEMPERATURES IN THE LOW TO MID 90S AND TYPICAL 20-30%
AFTERNOON CHANCES OF SHOWERS/STORMS THROUGH MOST OF THE WEEK AS A
HIGH PRESSURE RIDGE BUILDS OVER THE SE/CENTRAL CONUS.
DESPITE LOW-LVL HIGH PRESSURE AXIS AND SLOWLY BUILDING HEIGHT
INFLUENCE OVER REGION MOST OF THE WEEK, PWATS WILL REMAIN ELEVATED
/NEAR 2"/ AND COMBINED WITH DAILY AFTERNOON INSTABILITY /2000 J/KG+/,
ISOLATED/SCATTERED SHOWERS/STORMS WILL BE LIKELY. OVERALL COVERAGE
WONT BE GREAT BUT FEEL BEST COVERAGE WILL BE IN S/SE/E WHERE SEA-
BREEZE CONVERGENCE AND HIGHEST PWATS WILL EXIST. HEAT INDICES MONDAY
AND TUESDAY SHOULD REACH INTO THE LOW 100S FOR A FEW HOURS WITH LOWS
ONLY FALLING INTO THE LOW TO MID 70S THROUGH MUCH OF THE WEEK.
ON TUESDAY...A SLIGHTLY STRONGER S/WV TROUGH ACROSS THE CORN BELT
WILL ATTEMPT TO BRING A BOUNDARY SOUTH TOWARDS THE REGION BUT FEEL
IT STAY NORTH AND THUS KEPT POPS/SHOWERS OUT OF FORECAST FOR
NORTHERN AREAS. FOR WEDNESDAY THROUGH FRIDAY...RIDGING WILL REMAIN
OVER AREA AND STRENGTHEN SLIGHTLY BUT SEA-BREEZE INITIATED AND
DIURNAL ACTIVITY SHOULD CONTINUE TO BE A GOOD POSSIBILITY EACH DAY.
BY SATURDAY, THE RIDGING SLIPS FARTHER WEST AND PLACES REGION IN
SLIGHTLY GREATER N/NE FLOW THAT COULD ENHANCE SHOWER COVERAGE
POSSIBILITIES. /ALLEN/
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
DL/BB/26/ALLEN
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
401 PM CDT Fri Aug 29 2014
.DISCUSSION...
Issued at 401 PM CDT FRI AUG 29 2014
Out of the gate this afternoon...first round of convection continuing
to track east-northeast as initial shot of vorticity and pressure
advection associated with inbound upper wave slides east across the
region. Upstream behind this afternoon/s activity...skies have
cleared and weak destabilization has occurred with latest SPC
mesoanalysis suggesting anywhere between 1000-1500 J/Kg of MLCAPE
exists across eastern KS and western MO. Heading into the late
afternoon...main concern is for redeveloping convection as next piece
of shortwave energy and associated vorticity slides over the area. As
this occurs...long-lived frontal boundary which has been in place
across the central Plains in recent days should slowly slide across
the region which should also help with possible redevelopment. Fcst
models have been playing this card quite well with latest HRRR high-
res data supporting renewed convection across eastern KS this afternoon.
For now...have advertised chc pops pretty much across the western
2/3rds of the fcst area...before gradually spreading them east during
the early overnight period. In terms of severe threats...latest
mesoanalysis shows fairly weak shear aloft. This along with a DCAPE
min/trough across our region should largely prevent widespread
severe. That said though...a few strong downbursts cannot be ruled
out if convection actually does develop.
Main front to slide through the forecast area tonight as discussed
above. This should result in a gradual decrease in storm coverage
from west to east during the early morning hrs if storms do in fact
develop. Overnight lows tonight will largely reside in the middle to
upper 60s.
By all accounts...upcoming holiday weekend shaping up to be
beautiful...at least early on that is as region will reside in a post
frontal airmass both Saturday and Sunday. Despite the fropa
tonight...limited to no cooling seeing in the 850-mb temp field thus
expect high temps in the mid to upper 80s on Saturday...and
potentially into the lower to middle 90s on Sunday as warm air
advection increases ahead of next incoming wave/front.
Much more interesting weather by Sunday night/early Monday as well
advertised longwave trough continues to dig along the Front Range. As
this occurs...cyclogenesis expected across the northern Plains with
strengthening future then expected to quickly exit into the upper
Miss Vly/western Great Lakes region by early Monday. The end result
for our area will be a slowly progressing cold front which will begin
sliding south during this period...with increasing chances for rain
from Sunday night through the Tuesday time frame. Main issue seen
from this vantage point is that this feature will likely stall
somewhere across central Missouri as it begins to interact with stout
sfc ridging in place across the lwr Miss Vly and southern Plains. A
severe wx concern initially Sunday night may quickly morph into a
hydro concern as continued moisture advection resulting from a
strengthening low-level jet of 2-3 standard deviations above normal
ascends the stalled feature and cloud layer winds remain parallel to
the front. Will have to maintain vigilance with this feature as many
locations across our northwestern zones have received heavy rainfall
in recent days. If severe wx were to develop Sunday night...bulk
shear vectors orientation parallel to the incoming front will likely
support multicell type storm morphologies...with high winds winds
posing the biggest threat before concerns change over to possible
heavy rain. That said...better frontal convergence for forced ascent
will likely remain north of our fcst area which could ultimately
limit the severe threat for our region. In any event...both flooding
and possible severe pose a risk as seen this afternoon and will
maintain mention in the HWO product for now.
Beyond this...returning southerly flow will finally lift the front
north across the region with dry weather returning in its wake by
midweek. With zonal flow expected to dominate across the lower
48...temps through the conclusion of the period should remain near or
slightly above normal.
&&
.AVIATION...(For the 18Z TAFS through 18Z Saturday Afternoon)
Issued at 1227 PM CDT FRI AUG 29 2014
Complicated fcst this afternoon as large scale upper trough and
associated cold front will move through the area this
afternoon/evening. That said...latest radar trends showing a decent
swath of rain inbound to MCI with upstream obs over eastern KS
supporting a tempo IFR mention out of the gate. As this activity
clears to the north by 20z or so...attention then shifts to areas
upstream which are now destabilizing thanks to mostly clear skies. As
result...expect renewed shwr/storm activity later this afternoon with
a second tempo group added at all sites to account for this
possibility. Skies to slowly clear from west to east overnight which
should give rise to developing VSBY and low CIG restrictions. For
now...IFR restrictions offered at STJ with MVFR elsewhere.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
UPDATE...32
DISCUSSION...32
AVIATION...32
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1228 PM CDT Fri Aug 29 2014
.UPDATE...
Issued at 1012 AM CDT FRI AUG 29 2014
Quick update this morning to account for latest radar and satellite
trends. Fairly potent upper-level wave inbound this morning as
seen on latest water vapor imagery. Ahead of this feature...upper-
level pressure along the 1.5 PVU surface showing a nice "treble clef"
signature with latest RUC analysis showing the trop undulation down
to almost 500-mb...not bad for this time of year! Pressure advection
in advance of this feature combined with decent upper divergence
aloft should continue to support organized shwrs and thunderstorms.
As this feature continues sliding east this morning...expect a
gradual increase in precip chances from west to east which should
result in very beneficial rainfall for a good portion of the area. In
general...QPF totals will likely range from a quarter to half
inch...with localized higher amounts possible with thunderstorm
activity. Pop/wx grids updated to reflect a slightly delayed arrival
time...but overall fcst trends remain unchanged.
&&
.SHORT TERM...(Today through Sunday)
Issued at 326 AM CDT FRI AUG 29 2014
For today, areas of scattered thunderstorms will continue to develop
along and ahead of an eastward-moving shortwave trough, resulting in
slowly increasing chances of precipitation this morning into the
evening across the CWA. The best chance of storms will spread from
early afternoon across eastern KS and far western MO to late evening
in central MO. Afternoon temperatures will be held down by clouds
and precipitation, keeping highs mainly in the 80s and the highest
readings in central MO where storms will be later to arrive. Not
much instability is expected to develop today with clouds arriving
early and temperatures aloft and no real significant temperature
perturbation along the trough to increase lapse rates, so do not
expect much of a strong/severe storm threat this afternoon or this
evening. However, if areas of central MO see a few peeks of sun
through early afternoon, an isolated more robust storm could develop
and could produce briefly gusty winds.
Precipitation will generally clear out from northwest to southeast
on Friday night, but may linger into Saturday across portions of
central MO as a second weak shortwave trough rides up over central
MO, especially if the weak surface boundary associated with today`s
shortwave trough can stall over the region and support convective
initiation on Saturday. High temperatures should be several degrees
warmer for Saturday and especially Sunday as skies clear, southerly
surface flow returns, and 850 hPa temperatures remain in the 18 to
21 C range.
The next round of thunderstorms is expected to be a bit more robust
Sunday night into early Monday morning along a southeastward moving
cold front. General model consensus brings the front through the CWA
between midnight and 9 AM Monday morning, although timing could
change a bit. MUCAPE values in the 1000-2000 J/kg range and bulk
shear values as high as 40 kts could support organized, potentially
strong multicell storms especially across northwest MO. Heavy rain
is also a threat with PWATs climbing to around 2 inches and bulk
shear vectors orienting parallel to the front to support training
storms. The overall severe threat will depend on timing of frontal
passage as storms should become elevated with time and instability
will decrease, but is expected mainly across northwest and northern
MO where upper-level forcing and flow is a bit stronger.
.LONG TERM...(Monday through Thursday)
Issued at 326 AM CDT FRI AUG 29 2014
A complex of showers and thunderstorms will likely be ongoing over
portions of the forecast area Monday morning as a cold front settles
into northwest Missouri. While not an optimal diurnal time for
severe weather with only modest instability forecast, will need to
monitor potential as dynamics from the large upper trough over the
northern tier of the country will yield moderate shear in advance of
the cold front. The upper trough will gradually deamplify, leaving
the surface cold front largely stationary Monday into Tuesday across
the northern half of the CWA. Periodic thunderstorm chances will
remain possible through Tuesday night as the region remains on the
southern periphery of strong upper dynamics and associated embedded
shortwave troughs traversing the area. A few storms may be strong
with moderate shear and instability, especially during the afternoon
and evening hours. With the boundary layer winds expected to remain
weak, the primary threat would be brief periods of damaging wind
gusts and hail to quarter-size. Pinpointing the timing and
specific locations of highest precipitation potential remains
challenging at this stage with convective details that will play
some role in frontal position and windows of strongest ascent both
unresolved.
The surface boundary is expected to retreat northward as a warm
front by Wednesday as heights begin to rise across the region. Only
a slight chance of thunderstorms is anticipated on Wednesday, with
dry conditions for the remainder of the work week. Likewise,
temperatures will return to above normal readings, with afternoon
highs in the upper 80s to lower 90s.
&&
.AVIATION...(For the 18Z TAFS through 18Z Saturday Afternoon)
Issued at 1227 PM CDT FRI AUG 29 2014
Complicated fcst this afternoon as large scale upper trough and
associated cold front will move through the area this
afternoon/evening. That said...latest radar trends showing a decent
swath of rain inbound to MCI with upstream obs over eastern KS
supporting a tempo IFR mention out of the gate. As this activity
clears to the north by 20z or so...attention then shifts to areas
upstream which are now destabilizing thanks to mostly clear skies. As
result...expect renewed shwr/storm activity later this afternoon with
a second tempo group added at all sites to account for this
possibility. Skies to slowly clear from west to east overnight which
should give rise to developing VSBY and low CIG restrictions. For
now...IFR restrictions offered at STJ with MVFR elsewhere.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
UPDATE...32
SHORT TERM...Laflin
LONG TERM...Blair
AVIATION...32
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1012 AM CDT Fri Aug 29 2014
.UPDATE...
Issued at 1012 AM CDT FRI AUG 29 2014
Quick update this morning to account for latest radar and satellite
trends. Fairly potent upper-level wave inbound this morning as
seen on latest water vapor imagery. Ahead of this feature...upper-
level pressure along the 1.5 PVU surface showing a nice "treble clef"
signature with latest RUC analysis showing the trop undulation down
to almost 500-mb...not bad for this time of year! Pressure advection
in advance of this feature combined with decent upper divergence
aloft should continue to support organized shwrs and thunderstorms.
As this feature continues sliding east this morning...expect a
gradual increase in precip chances from west to east which should
result in very beneficial rainfall for a good portion of the area. In
general...QPF totals will likely range from a quarter to half
inch...with localized higher amounts possible with thunderstorm
activity. Pop/wx grids updated to reflect a slightly delayed arrival
time...but overall fcst trends remain unchanged.
&&
.SHORT TERM...(Today through Sunday)
Issued at 326 AM CDT FRI AUG 29 2014
For today, areas of scattered thunderstorms will continue to develop
along and ahead of an eastward-moving shortwave trough, resulting in
slowly increasing chances of precipitation this morning into the
evening across the CWA. The best chance of storms will spread from
early afternoon across eastern KS and far western MO to late evening
in central MO. Afternoon temperatures will be held down by clouds
and precipitation, keeping highs mainly in the 80s and the highest
readings in central MO where storms will be later to arrive. Not
much instability is expected to develop today with clouds arriving
early and temperatures aloft and no real significant temperature
perturbation along the trough to increase lapse rates, so do not
expect much of a strong/severe storm threat this afternoon or this
evening. However, if areas of central MO see a few peeks of sun
through early afternoon, an isolated more robust storm could develop
and could produce briefly gusty winds.
Precipitation will generally clear out from northwest to southeast
on Friday night, but may linger into Saturday across portions of
central MO as a second weak shortwave trough rides up over central
MO, especially if the weak surface boundary associated with today`s
shortwave trough can stall over the region and support convective
initiation on Saturday. High temperatures should be several degrees
warmer for Saturday and especially Sunday as skies clear, southerly
surface flow returns, and 850 hPa temperatures remain in the 18 to
21 C range.
The next round of thunderstorms is expected to be a bit more robust
Sunday night into early Monday morning along a southeastward moving
cold front. General model consensus brings the front through the CWA
between midnight and 9 AM Monday morning, although timing could
change a bit. MUCAPE values in the 1000-2000 J/kg range and bulk
shear values as high as 40 kts could support organized, potentially
strong multicell storms especially across northwest MO. Heavy rain
is also a threat with PWATs climbing to around 2 inches and bulk
shear vectors orienting parallel to the front to support training
storms. The overall severe threat will depend on timing of frontal
passage as storms should become elevated with time and instability
will decrease, but is expected mainly across northwest and northern
MO where upper-level forcing and flow is a bit stronger.
.LONG TERM...(Monday through Thursday)
Issued at 326 AM CDT FRI AUG 29 2014
A complex of showers and thunderstorms will likely be ongoing over
portions of the forecast area Monday morning as a cold front settles
into northwest Missouri. While not an optimal diurnal time for
severe weather with only modest instability forecast, will need to
monitor potential as dynamics from the large upper trough over the
northern tier of the country will yield moderate shear in advance of
the cold front. The upper trough will gradually deamplify, leaving
the surface cold front largely stationary Monday into Tuesday across
the northern half of the CWA. Periodic thunderstorm chances will
remain possible through Tuesday night as the region remains on the
southern periphery of strong upper dynamics and associated embedded
shortwave troughs traversing the area. A few storms may be strong
with moderate shear and instability, especially during the afternoon
and evening hours. With the boundary layer winds expected to remain
weak, the primary threat would be brief periods of damaging wind
gusts and hail to quarter-size. Pinpointing the timing and
specific locations of highest precipitation potential remains
challenging at this stage with convective details that will play
some role in frontal position and windows of strongest ascent both
unresolved.
The surface boundary is expected to retreat northward as a warm
front by Wednesday as heights begin to rise across the region. Only
a slight chance of thunderstorms is anticipated on Wednesday, with
dry conditions for the remainder of the work week. Likewise,
temperatures will return to above normal readings, with afternoon
highs in the upper 80s to lower 90s.
&&
.AVIATION...(For the 12Z TAFS through 12Z Saturday Morning)
Issued at 628 AM CDT FRI AUG 29 2014
VFR conditions are expected through most of the morning and early
afternoon across the region; however, a few isolated storms could
form in the vicinity of all TAF sites by 14z-17z along with scattered
to broken 4-5 kft ceilings. Showers and storms should become more
numerous across western MO this afternoon, then should push out of
the terminals between 00z-03z. Winds will become light and variable
early Saturday morning, resulting in patchy fog that could become
dense in places.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
UPDATE...32
SHORT TERM...Laflin
LONG TERM...Blair
AVIATION...Laflin
AREA FORECAST DISCUSSION
NWS BILLINGS MT
929 PM MDT SAT AUG 30 2014
.UPDATE...
EVENING CONVECTION HAS WEAKENED WITH STRONGEST ACTIVITY HAVING
MOVED INTO THE DAKOTAS. REGIONAL RADAR SHOWING SOME ACTIVITY
MOVING INTO SOUTHWEST MONTANA SO DO EXPECT ANOTHER SHOT OF SHOWERS
LATER TONIGHT BUT CURRENT ACTIVITY IS VERY ISOLATED. DOES NOT LOOK
QUITE AS WET WITH THE NEXT ROUND AS PREVIOUSLY THOUGHT AS JET
ENERGY OVER OREGON IS TAKING A MORE SOUTHERN TRACK WHICH WILL PUT
BEST LIFT OVER SOUTHEAST IDAHO AND WESTERN WYOMING. UPDATED
FORECASTS. BORSUM
&&
.SHORT TERM...VALID FOR TDY AND SUN...
SERIES OF SHORTWAVES IN THE CYCLONIC FLOW ALOFT ARE PROGRESSING
ACROSS THE FORECAST AREA THIS AFTERNOON. INITIAL SHORTWAVE IS
PUSHING ACROSS FAR EASTERN MONTANA AND WILL EXIT INTO THE DAKOTAS
LATER THIS AFTERNOON. A SECONDARY WAVE IS PUSHING INTO SOUTH
CENTRAL MONTANA OUT OF YELLOWSTONE PARK. LIGHTNING ACTIVITY HAS
BEEN MORE VIGOROUS WITH THIS WAVE ALL MORNING...EVEN BACK OVER
IDAHO EARLIER...INDICATING ENHANCED MID-LEVEL INSTABILITY. WOULD
STILL NOT RULE OUT A LINE OF THUNDERSTORMS DEVELOPING ACROSS
FALLON AND CARTER COUNTIES WITH THE INITIAL WAVE. IN
FACT...A THUNDERSTORM HAS STARTED TO DEVELOP NORTHEAST OF
GILLETTE WITH THIS LINE...AND IT REMAINS TO BE SEEN WHETHER A LINE
CAN UNZIP NORTHWARD DESPITE THE CIN THAT REMAINS IN PLACE. IF A
LINE CAN DEVELOP THERE...IT WILL PROVIDE THE BEST CHANCE AT AN
ISOLATED SEVERE REPORT BEFORE THE LINE EXITS INTO THE DAKOTAS.
THE SECONDARY WAVE IS STARTING TO DEVELOP A LINE FROM JUST SOUTH
OF RED LODGE DOWN TOWARD JACKSON WYOMING. TREND IN THE HRRR HAS
BEEN TO EVOLVE THIS LINE ACROSS BIG HORN COUNTY AND SOUTHEAST
MONTANA THROUGH THIS EVENING...WITH SOME STRONGER CELLS EMBEDDED.
MAIN THREATS WITH THIS LINE OF STORMS WILL LIKELY BE HEAVY
RAIN...FREQUENT LIGHTNING AND SMALL HAIL. WHILE WOULDNT RULE OUT
A SEVERE REPORT...ELEVATED NATURE OF THE CONVECTION BEHIND THE
SURFACE FRONT SHOULD HELP TO PRECLUDE ANY SEVERE ACTIVITY.
CYCLONIC FLOW WITH WEAK EMBEDDED SHORTWAVES WILL REMAIN IN PLACE
OVER THE FORECAST AREA THROUGH SUNDAY MORNING...THUS KEEPING AN
OVERALL WET FORECAST GOING THROUGH MID DAY SUNDAY. COULD SEE A
BREAK IN THE ACTIVITY BY SUNDAY AFTERNOON AND EVENING...BEFORE
MORE ISOLATED/SCATTERED SHOWERS DEVELOP ACROSS THE AREA MONDAY
AFTERNOON AS THE CYCLONIC FLOW REMAINS IN PLACE ALOFT.
TEMPERATURES THROUGH THIS PERIOD WILL REMAIN COOLER...WITH DAY
TIME HIGHS ONLY EXPECTED IN THE LOW 70S ON SUNDAY AND MONDAY.
CHURCH
.LONG TERM...VALID FOR MON...TUE...WED...THU...FRI...
EXTENDED FORECAST STARTS OFF QUIET FOR TUESDAY INTO WEDNESDAY AS MODELS
CONSISTENT WITH ZONAL DOWNSLOPE FLOW ACROSS THE AREA. CONDITIONS
BEGIN TO CHANGE LATE WEDNESDAY AS SYSTEM OVER WESTERN CANADA DROPS
SOUTH AND DEFLECTS THE FLOW OVER MONTANA TO THE SOUTHWEST
INCREASING THE CHANCES FOR AFTERNOON AND EVENING THUNDERSTORMS.
THE LATEST ECMWF AND CANADIAN SOLUTIONS DRAG THE BULK OF THE
PACIFIC SYSTEM THROUGH THE AREA ON THURSDAY WHILE THE GFS IS
SLOWER AND A BIT FURTHER NORTH WITH THIS FORCING AND THE BETTER
PRECIPITATION CHANCES. WEAK ENERGY AND GENERAL TROFINESS RESIDES
OVER THE AREA BEHIND THE SYSTEM INTO NEXT WEEKEND. SPLIT THE
DIFFERENCE BETWEEN THE MODELS ON THE TIMING OF STRONGEST FORCING
OVER THE AREA RESULTING IN THE HIGHEST PRECIPITATION CHANCES LATE
THURSDAY INTO FRIDAY...BUT IF ECMWF IS CORRECT THIS COULD BE A BIT
LATE. CONTINUED 20 TO 30 PERCENT PRECIPITATION CHANCES INTO THE
WEEKEND. TRENDED TEMPERATURES DOWN FROM WEDNESDAY INTO THE WEEKEND
WITH MID 70S WEDNESDAY DROPPING INTO THE UPPER 60S FOR THURSDAY
AND FRIDAY. CHAMBERS
&&
.AVIATION...
SCATTERED SHOWERS AND A FEW TSTMS WILL IMPACT THE AREA THROUGH THE
REMAINDER OF THE EVENING...WITH ANY CHANCE OF STRONGER STORMS
HAVING SHIFTED INTO THE DAKOTAS. ANOTHER DISTURBANCE FROM THE WEST
WILL BRING INCREASING SHOWERS ESPECIALLY WEST AND SOUTH OF KBIL
LATER TONIGHT...WITH ACTIVITY SPREADING EAST SUNDAY. AREAS OF MVFR
AND FREQUENT MOUNTAIN OBSCURATIONS CAN BE EXPECTED BETWEEN 06-18Z.
JKL
&&
.PRELIMINARY POINT TEMP/POPS...
TDY SUN MON TUE WED THU FRI
-------------------------------------------------------
BIL 071 054/068 051/069 050/078 054/077 050/069 049/069
7/T 44/T 22/T 10/U 11/U 22/T 33/T
LVM 071 046/066 043/068 043/079 046/077 043/068 044/069
7/T 43/T 22/T 10/U 12/T 23/T 33/T
HDN 074 054/069 051/071 051/080 053/081 051/072 051/073
6/T 45/T 22/T 10/U 11/U 12/T 33/T
MLS 077 056/072 052/073 052/079 054/080 053/071 053/072
4/T 34/T 12/T 10/U 01/U 12/T 22/T
4BQ 083 055/066 051/070 051/080 053/083 052/072 051/073
5/T 35/T 23/T 10/U 01/U 22/T 33/T
BHK 079 054/071 049/070 049/077 051/080 050/073 049/070
5/T 53/T 13/T 10/U 12/T 22/T 22/T
SHR 080 052/065 047/070 046/080 050/083 049/073 048/075
6/T 35/T 22/T 10/U 11/U 12/T 33/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
238 PM CDT FRI AUG 29 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 238 PM CDT FRI AUG 29 2014
THE MAIN FORECAST CHALLENGE REMAINS A MINIMAL THREAT FOR
PRECIPITATION THIS EVENING. FOR THIS EVENING AND THE
OVERNIGHT...COMPACT PV ANOMALY OVER SE NEBRASKA WILL CONTINUE TO
THE EAST NORTHEAST WHILE THE NEXT DISTURBANCE CURRENTLY ENTERING
THE WESTERN DAKOTAS PUSHES EAST INTO THE REGION. SHOWERS AND
STORMS WILL EXIT NORTH CENTRAL NEBRASKA WHILE ADDITIONAL STORMS
FORM ACROSS THE NORTHWEST WITH THE APPROACH OF THE SECOND
DISTURBANCE. PROXIMITY SOUNDINGS ACROSS THE AREA SHOW
SIGNIFICANTLY LESS MOISTURE AS COMPARED TO A DAY OR TWO AGO. SHEAR
IS LIMITED AT BEST IN A LOW CAPE ENVIRONMENT AS WELL...SO ISOLATED
PULSE STORMS WOULD BE ANTICIPATED AT BEST. WILL CARRY A SLIGHT
CHANCE MENTION ACROSS THE SANDHILLS AND NORTH CENTRAL NEBRASKA
THIS EVENING...BUT WITH THE COOLING...STORMS SHOULD BE OVER BY
03-04Z. WITH DRY AIR ALOFT PUSHING IN FROM THE WEST...BUT A
RELATIVELY MOIST BL...FOG MAY BE A CONCERN FOR OUR EAST AND IN
FAVORED RIVER VALLEYS. WILL INTRODUCE PATCHY WORDING IN THE
FORECAST FOR NOW AROUND THE DAWN HOURS.
TRANSITORY SHORTWAVE RIDGING TO BUILD ACROSS THE NORTHERN AND
CENTRAL PLAINS ON SATURDAY. WITH AN OVERALL LACK OF KINEMATIC
FORCING AND A DRIER AIRMASS IN PLACE...STORMS AND/OR SHOWERS ARE NOT
ANTICIPATED THROUGH 00Z SUNDAY. AFTER PLEASANTLY COOL LOWS IN THE
50S SATURDAY MORNING...HIGHS SHOULD REBOUND INTO THE 80S FOR MOST
LOCATIONS.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 238 PM CDT FRI AUG 29 2014
SATURDAY NIGHT THROUGH MONDAY...
A LEAD DISTURBANCE WILL EMERGE ONTO THE PLAINS REGION SATURDAY
NIGHT. MOISTURE WILL REMAIN SOMEWHAT LIMITED...BUT WILL BE OFFSET BY
A DEVELOPING LOW LEVEL JET. COVERAGE SHOULD MOSTLY BE ISOLATED AND
HAVE A SLIGHT CHANCE OVERNIGHT...EXCEPT NEAR 30 PERCENT CHANCE IN
THE NORTHEAST.
ON SUNDAY...UPPER TROUGH WILL MOVE INTO WESTERN NEBRASKA AS A COLD
FRONT MOVES SOUTHEAST. THE COLD FRONT IS FORECAST BY MODELS TO BE
SLIGHTLY FASTER AND HAVE LOWERED POPS MOST AREAS TO 20 TO 40
PERCENT. AREAS EAST OF ONEILL THROUGH STOCKVILLE WILL HAVE A 40 TO
50 POP SUNDAY AFTERNOON/EARLY EVENING WHERE STRONG LIFT ALONG THE
FRONT COULD PRODUCE A FEW STRONG TO SEVERE STORMS.
ON MONDAY...FLOW WILL REMAIN FAIRLY ZONAL. SOMEWHAT DRIER AIR WILL
WORK INTO WRN NEBR AS DEWPOINTS RANGE FROM THE MID 40S TO LOW 50S
WEST TO THE LOWER TO MID 50S SOUTHEAST. A WEAK DISTURBANCE WILL
PRODUCE CONVECTION FROM EASTERN WY INTO WRN SOUTH DAKOTA. A FEW
STORMS MAY MOVE INTO THE PANHANDLE AND FAR NWRN FORECAST AREA BY
LATE AFTERNOON.
MONDAY NIGHT THROUGH FRIDAY...
A DISTURBANCE IS INDICATED FROM EASTERN MT INTO EASTERN WYOMING
MONDAY AFTERNOON...WHICH WILL MOVE ACROSS THE NRN AND CNTRL PLAINS
MONDAY NIGHT. MOISTURE RETURN WILL BE VERY LIMITED AND MAINTAINING
ONLY SLIGHT CHANCE POPS FOR MONDAY NIGHT LOOKS APPROPRIATE.
UPPER FLOW ACROSS THE CENTRAL PLAINS WILL BE ZONAL ON TUESDAY AND
GRADUALLY TRANSITION TO SOUTHWEST FLOW BY WEDNESDAY NIGHT.
THIS IN RESPONSE TO AN UPPER TROUGH DIGGING INTO THE PACIFIC
NORTHWEST AND AN UPPER RIDGE PERSISTING OVER THE TENNESSEE VALLEY.
HIGHS WILL WARM FROM THE MID 80S TUESDAY TO THE MID/UPPER 80S
WEDNESDAY. BY THURSDAY...SURFACE LOW PRESSURE WILL DEEPEN IN WESTERN
KANSAS AS CANADIAN HIGH PRESSURE BUILDS INTO THE NORTHERN PLAINS.
THIS WILL SETTLE A COLD FRONT INTO SOUTHERN NEBRASKA DURING THE DAY
WITH CHANCES FOR THUNDERSTORMS THURSDAY INTO FRIDAY. THE 12Z GFS HAS
COME INTO FAIRLY GOOD AGREEMENT WITH THE ECMWF WITH POPS
APPROPRIATELY ADDED IN THURSDAY THROUGH FRIDAY. AS CANADIAN HIGH
PRESSURE BUILD IN THURSDAY NIGHT...HIGHS FRIDAY TO COOL TO THE MID
70S TO NEAR 80.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 102 PM CDT FRI AUG 29 2014
FOR THE 18Z TAF ISSUANCE...STORMS WILL ONCE AGAIN BE POSSIBLE
FOR MOST AREA TERMINALS THIS AFTERNOON AND EVENING. ATTM...THE
LATEST GUIDANCE INDICATES THE HIGHEST PROBABILITY OF STORMS ACROSS
CENTRAL AND NORTHERN TERMINALS. CONFIDENCE IS NOT ENOUGH TO
WARRANT A TSRA MENTION AT KLBF THIS EVENING. AT KVTN...DEBATED
WHETHER TO GO WITH VCTS OR ACTUAL TSRA...BUT EVENTUALLY SIDED WITH
THE LATEST HRRR WHICH INDICATES STORMS AFTER 00Z. ERRATIC WIND
AND MODERATE RAINFALL WOULD ACCOMPANY ANY STORM THAT DEVELOPS.
OTHERWISE ONGOING STORMS ACROSS FAR NORTH CENTRAL NEBRASKA WILL
CONTINUE THIS AFTERNOON. MVFR OR LOWER RESTRICTIONS CAN BE EXPECTED
AT KONL WHEN IMPACTED BY A STORM. FOG MAY BE A CONCERN TOMORROW
MORNING...GUIDANCE IS SUGGESTING REDUCED VISIBILITY AT BOTH KVTN
AND KLBF.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...JACOBS
LONG TERM...ROBERG
AVIATION...JACOBS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
102 PM CDT FRI AUG 29 2014
.SYNOPSIS...
ISSUED AT 359 AM CDT FRI AUG 29 2014
H5 ANALYSIS FROM EARLIER THIS EVENING HAS A VERY ACTIVE NORTHERN
STREAM ACROSS CANADA AND ALASKA WITH SEVERAL UPPER LEVEL LOWS
PRESENT. CLOSED LOWS WERE LOCATED OVER THE GULF OF
ALASKA...NORTHERN PORTIONS OF HUDSON BAY...THE CANADIAN
MARITIMES...AS WELL AS OFF THE COAST OF NRN ALASKA. ACROSS THE
CONUS...HIGH PRESSURE WAS PRESENT OFF THE COAST OF SRN CA...AS
WELL AS THE FAR SERN CONUS. CLOSER TO WESTERN AND NORTH CENTRAL
NEBRASKA...A TROUGH OF LOW PRESSURE EXTENDED FROM CENTRAL
PORTIONS OF THE DAKOTAS...SWD INTO THE TX PANHANDLE. UPSTREAM OF
THIS FEATURE...A NICE SHORTWAVE WAS PRESENT OVER SRN PORTIONS OF
MT. RADAR IMAGERY ACROSS THE CENTRAL AND SRN PLAINS...HAS A NICE
AREA OF SHOWERS AND THUNDERSTORMS EXTENDING FROM EASTERN KS INTO
FAR EASTERN NEBRASKA THIS MORNING WITH ALL ACTIVITY OFF TO THE
EAST OF THE FORECAST AREA. SKIES HAVE GRADUALLY CLEARED OVERNIGHT
WEST OF A LINE FROM ATKINSON TO BROKEN BOW WHERE DRIER MID LEVEL
AIR HAS PUSHED INTO CENTRAL AND WESTERN NEBRASKA. TEMPERATURES AS
OF 3 AM CDT...RANGED FROM 54 AT OGALLALA TO 65 AT BROKEN BOW.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 359 AM CDT FRI AUG 29 2014
FOR TODAY AND TONIGHT...THE MAIN FORECAST CHALLENGE IS A MINIMAL
THREAT FOR PRECIPITATION THIS AFTERNOON AND EARLY THIS EVENING.
FOR TODAY...SKIES WILL CONTINUE TO CLEAR THIS MORNING IN THE
EASTERN CWA AS THE UPPER LEVEL TROUGH OF LOW PRESSURE SHIFTS EAST
INTO THE MISSOURI VALLEY. FURTHER WEST...SKIES WILL BEGIN TO
CLOUD UP THIS AFTERNOON AS THE BEFORE MENTIONED DISTURBANCE OVER
SRN MT APPROACHES THE NEBR PANHANDLE. WITH HEATING THIS
AFTERNOON...LOW AND MID LEVEL LAPSE RATES WILL STEEPEN
SIGNIFICANTLY...INCREASING THE THREAT FOR AN ISOLATED
THUNDERSTORM OR TWO. DECIDED TO KEEP SHOWER COVERAGE TO A MINIMUM
AS AVAILABLE MOISTURE IS SIGNIFICANTLY LESS THAN WHAT WE HAD A
COUPLE OF DAYS AGO. THIS IS EVIDENT IN PWATS OF 0.75 TO 1.00 INCH
VS. THE 1.5 TO 2.0 INCH PWATS OF A COUPLE OF DAYS AGO. WE WILL BE
IN A VERY WEAK SHEAR ENVIRONMENT AS WELL...SO STORMS WILL BE OF
THE PULSE TYPE WITH SHORT DURATION EXPECTED. WITH COOLING THIS
EVENING...THE THREAT FOR STORMS IS EXPECTED TO END QUICKLY BY 03Z.
AFTER HIGHS TODAY IN THE LOWER TO MIDDLE 80S...DRIER AIR WILL
PUSH INTO THE FORECAST AREA TONIGHT. THE COMBINATION OF DRIER AIR
AND CLEARING SKIES WILL ALLOW LOWS TO BOTTOM OUT IN THE LOWER TO
MIDDLE 50S.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 359 AM CDT FRI AUG 29 2014
SATURDAY WILL SEE THE HIGH PLAINS BETWEEN SUBTLE DISTURBANCES WITH
MODELS IN AGREEMENT WITH A LITTLE RIDGING OVERHEAD. THIS SHOULD
AID IN LITTLE CLOUD COVER THROUGH THE DAY. MOS GUIDANCE HAS TEMPS
WELL INTO THE 80S AND A FEW LOWER 90S. FORECAST IS ON THE
CONSERVATIVE SIDE...GOING WITH THE LOWER GUIDANCE OR SLIGHTLY
BELOW...CONSIDERING MOST AREAS HAVE RECEIVED AT LEAST A COUPLE OF
INCHES THE PAST FEW DAYS AND THE GROUND WILL STILL BE DAMP.
MEANWHILE EYES BEGIN TO FOCUS ON THE TROUGH MOVING INTO THE PAC
NW. THIS TROUGH WILL PUSH ACROSS THE ROCKIES EARLY ON SUNDAY...AS
A SFC COLD FRONT PUSHES ACROSS THE AREA. GOOD AGREEMENT WITH CAPE
VALUES OF 2K TO 4K J/KG AND 40 TO 55 KTS OF SHEAR AHEAD OF THE
FRONT. THE CONCERN IS WHERE THE FRONT WILL BE LOCATED AT PEAK
HEAT. GENERAL MODEL BLEND IS ACROSS CENTRAL NEBRASKA...WITH
THE EASTERN PORTIONS OF THE CWA TO SEE DEVELOPMENT. STEEP LAPSES
RATE POST FRONT MAY BE ENOUGH FOR SOME ISOLD/SCT SHOWERS.
ACTIVITY QUICKLY MOVES EAST SUNDAY NIGHT AND MODELS IN AGREEMENT
ENDING PRECIP BY MIDNIGHT...AND FORECAST HAS GONE DRY OVERNIGHT.
THIS WILL ALSO RESULT IN LESS CLOUD COVER AND COOL HIGH PRESSURE
BUILDING IN FROM THE WEST. FORECAST FOLLOWS COOL GUIDANCE WITH
TEMPS TRENDING COOLER.
ANOTHER DISTURBANCE WILL MOVE ACROSS THE AREA MONDAY NIGHT WITH
LOW POPS CONTINUED. THEN ZONAL FLOW WILL SLOWLY BECOME
WEST SOUTHWESTERLY. MODELS KEEP MOISTURE PLUM TO THE SOUTH OF THE
CWA...WITH MUCH OF THE WEEK EXPECTED TO BE DRY. TEMPS WILL BE ON
A SLOW CLIMB. TOWARDS THE END OF THE WORK WEEK...A TROUGH WILL
DIG IN ACROSS THE WESTERN COAST. THIS WILL CAUSE THE FLOW TO
BECOME MORE SOUTHWESTERLY. WILL HAVE TO MONITOR AS THIS SET UP
WILL LIKELY BRING A HIGHER CHANCE FOR POPS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 102 PM CDT FRI AUG 29 2014
FOR THE 18Z TAF ISSUANCE...STORMS WILL ONCE AGAIN BE POSSIBLE
FOR MOST AREA TERMINALS THIS AFTERNOON AND EVENING. ATTM...THE
LATEST GUIDANCE INDICATES THE HIGHEST PROBABILITY OF STORMS ACROSS
CENTRAL AND NORTHERN TERMINALS. CONFIDENCE IS NOT ENOUGH TO
WARRANT A TSRA MENTION AT KLBF THIS EVENING. AT KVTN...DEBATED
WHETHER TO GO WITH VCTS OR ACTUAL TSRA...BUT EVENTUALLY SIDED WITH
THE LATEST HRRR WHICH INDICATES STORMS AFTER 00Z. ERRATIC WIND
AND MODERATE RAINFALL WOULD ACCOMPANY ANY STORM THAT DEVELOPS.
OTHERWISE ONGOING STORMS ACROSS FAR NORTH CENTRAL NEBRASKA WILL
CONTINUE THIS AFTERNOON. MVFR OR LOWER RESTRICTIONS CAN BE EXPECTED
AT KONL WHEN IMPACTED BY A STORM. FOG MAY BE A CONCERN TOMORROW
MORNING...GUIDANCE IS SUGGESTING REDUCED VISIBILITY AT BOTH KVTN
AND KLBF.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CLB
SHORT TERM...CLB
LONG TERM...MASEK
AVIATION...JACOBS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1258 PM CDT FRI AUG 29 2014
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 325 AM CDT FRI AUG 29 2014
THE PRIMARY FORECAST CHALLENGES WILL BE IN REGARDS TO PCPN CHANCES
TODAY INTO TONIGHT AND THEN TIMING THE NEXT ROUND OF CONVECTION
SUNDAY INTO SUNDAY NIGHT. SOME SEVERE STORMS WILL BE POSSIBLE MAINLY
FROM SUNDAY AFTERNOON THROUGH SUNDAY EVENING.
MAIN FEATURES FROM THE UPPER AIR CHARTS LAST EVENING INCLUDED THE
FOLLOWING. AT 300 MB A JET SEGMENT OF AROUND 70 KNOTS WAS PUNCHING
NORTHEAST FROM SOUTHWEST KS. THIS WAS AHEAD OF A 500 MB TROUGH THAT
STRETCHED FROM THE DAKOTAS DOWN INTO WEST TEXAS. 12 HOUR HEIGHT
FALLS OF UP TO AROUND 40 METERS WERE NOTED AT AMARILLO AND DODGE
CITY. DECENT MOISTURE WAS STILL IN PLACE AT 700 MB AND 850 MB AHEAD
OF THE MID LEVEL TROUGH. THE KOAX SOUNDING WAS STILL FAIRLY MOIST
WITH 1.70 PRECIPITABLE WATER.
SURFACE ANALYSIS AT 08Z SHOWED LOW PRESSURE CENTERED OVER SOUTHEAST
SOUTH DAKOTA AND A COLD FRONT EXTENDING SOUTHWARD FROM THE LOW INTO
WEST TEXAS. DEWPOINTS WERE IN THE 60S TO LOWER 70S.
WATER VAPOR LOOP EARLY THIS MORNING SHOWED THAT THE TROUGH TO OUR
WEST HAD MADE SOME EASTWARD PROGRESS SINCE LAST EVENING. IT SHOULD
CONTINUE TO HAVE AN IMPACT ON US UNTIL A LITTLE AFTER MIDNIGHT
TONIGHT. KEPT FAIRLY HIGH POPS GOING TODAY...SINCE WE SHOULD SEE
REDEVELOPMENT THIS AFTERNOON WITH DAYTIME HEATING. FORECAST
SOUNDINGS FROM THE 00Z NAM INDICATED ELEVATED INSTABILITY OF OVER
2000 J/KG BY AROUND NOON. RECENT RUNS OF THE RAP MODEL SHOW AN
INCREASE IN PCPN COVERAGE AFTER 1 PM. HIGHS WILL BE MAINLY IN THE
UPPER 70S AND LOWER 80S. LOWS TONIGHT SHOULD DROP TO THE LOWER AND
MID 60S AS DRIER AIR WORKS ITS WAY IN FROM THE NORTHWEST BEHIND THE
COLD FRONT. SOME PATCHY FOG COULD DEVELOP LATE TONIGHT...BUT OVERALL
THE ATMOSPHERE WILL BE DRYING OUT.
SATURDAY LOOKS LIKE A DECENT DAY WITH A FAIR AMOUNT OF SUNSHINE AND
HIGHS IN THE 80S. CLOUDS WILL START TO INCREASE SATURDAY NIGHT...
ESPECIALLY IN OUR FAR WESTERN ZONES. KEPT A SMALL CHANCE OF LATE
NIGHT TSTMS IN NORTHEAST NEBRASKA.
MODELS HAVE SOME TIMING DIFFERENCES FOR SUNDAY INTO SUNDAY NIGHT.
KEPT SOME LOW POPS LATE SATURDAY NIGHT WEST OF A LINE FROM WAYNE TO
COLUMBUS. 00Z RUNS OF THE NAM AND CANADIAN MODEL WERE A BIT SLOWER
WITH DEVELOPMENT OF STORMS SUNDAY AFTERNOON. FOR NOW...BLENDED IN
SOME OF THE GFS AND ECMWF WHICH SHOW SOME RAINFALL AMOUNTS OVER A
QUARTER OF AN INCH SUNDAY AFTERNOON. IF THE NAM IS MORE CORRECT...
THE SEVERE WEATHER POTENTIAL IS PROBABLY HIGHER SUNDAY EVENING THAN
IF THE GFS AND ECMWF VERIFY BETTER. LOOK FOR HIGHS MAINLY IN THE
80S AND MAYBE NEAR 90 FOR PARTS OF SOUTHEAST NEBRASKA.
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 325 AM CDT FRI AUG 29 2014
TRENDED POPS DOWNWARD SUNDAY NIGHT FROM NORTHWEST TO SOUTHEAST AS
THE SYSTEM MOVES THROUGH...BUT LINGERED A SLIGHT CHANCE OF TSTMS
INTO MONDAY MORNING.
A 500 MB LONGWAVE TROUGH AXIS WILL BE LOCATED OVER THE EASTERN
ROCKIES AND WESTERN HIGH PLAINS AT THE BEGINNING OF THIS PERIOD.
BY TUESDAY...THAT SHIFTS EAST OF OUR AREA AND THEN THE FLOW IS
FAIRLY ZONAL ACROSS MID AMERICA INTO WEDNESDAY. LATER IN THE WEEK
ANOTHER TROUGH WILL DIG INTO THE PACIFIC NORTHWEST...WITH OUR
AREA UNDER THE INFLUENCE OF SOUTHWEST MID LEVEL FLOW. ALTHOUGH
THUNDERSTORM CHANCES WILL NOT BE COMPLETELY ABSENT...NEXT WEEK
SHOULD BE A LOT DRIER THAN THIS WEEK HAS BEEN. HIGHS WILL MODERATE
FROM MAINLY 80S TO AROUND 90 AND LOWS WILL INCREASE FROM 60S TO
AROUND 70 OR THE LOWER 70S.
&&
.AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1250 PM CDT FRI AUG 29 2014
SCATTERED CONVECTION IS LIKELY ACROSS EASTERN NEBRASKA THROUGH 00Z
AS VIGOROUS UPPER WAVE OVER THE CENTRAL PLAINS MOVES EAST. MVFR
CONDITIONS EXPECTED DURING THIS TIME FOLLOWED BY A PERIOD OF VFR
THROUGH ABOUT 08Z. MVFR TO IFR CONDITIONS IN FOG AND CIGS EXPECTED
AFTER 08Z THRU ABOUT 14Z WITH LIGHT WINDS AND ABUNDANT LOW LEVEL
MOISTURE IN PLACE. VFR CONDITIONS THEN DEVELOPING 14Z-18Z.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...MILLER
LONG TERM...MILLER
AVIATION...FOBERT
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
658 AM CDT FRI AUG 29 2014
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 325 AM CDT FRI AUG 29 2014
THE PRIMARY FORECAST CHALLENGES WILL BE IN REGARDS TO PCPN CHANCES
TODAY INTO TONIGHT AND THEN TIMING THE NEXT ROUND OF CONVECTION
SUNDAY INTO SUNDAY NIGHT. SOME SEVERE STORMS WILL BE POSSIBLE MAINLY
FROM SUNDAY AFTERNOON THROUGH SUNDAY EVENING.
MAIN FEATURES FROM THE UPPER AIR CHARTS LAST EVENING INCLUDED THE
FOLLOWING. AT 300 MB A JET SEGMENT OF AROUND 70 KNOTS WAS PUNCHING
NORTHEAST FROM SOUTHWEST KS. THIS WAS AHEAD OF A 500 MB TROUGH THAT
STRETCHED FROM THE DAKOTAS DOWN INTO WEST TEXAS. 12 HOUR HEIGHT
FALLS OF UP TO AROUND 40 METERS WERE NOTED AT AMARILLO AND DODGE
CITY. DECENT MOISTURE WAS STILL IN PLACE AT 700 MB AND 850 MB AHEAD
OF THE MID LEVEL TROUGH. THE KOAX SOUNDING WAS STILL FAIRLY MOIST
WITH 1.70 PRECIPITABLE WATER.
SURFACE ANALYSIS AT 08Z SHOWED LOW PRESSURE CENTERED OVER SOUTHEAST
SOUTH DAKOTA AND A COLD FRONT EXTENDING SOUTHWARD FROM THE LOW INTO
WEST TEXAS. DEWPOINTS WERE IN THE 60S TO LOWER 70S.
WATER VAPOR LOOP EARLY THIS MORNING SHOWED THAT THE TROUGH TO OUR
WEST HAD MADE SOME EASTWARD PROGRESS SINCE LAST EVENING. IT SHOULD
CONTINUE TO HAVE AN IMPACT ON US UNTIL A LITTLE AFTER MIDNIGHT
TONIGHT. KEPT FAIRLY HIGH POPS GOING TODAY...SINCE WE SHOULD SEE
REDEVELOPMENT THIS AFTERNOON WITH DAYTIME HEATING. FORECAST
SOUNDINGS FROM THE 00Z NAM INDICATED ELEVATED INSTABILITY OF OVER
2000 J/KG BY AROUND NOON. RECENT RUNS OF THE RAP MODEL SHOW AN
INCREASE IN PCPN COVERAGE AFTER 1 PM. HIGHS WILL BE MAINLY IN THE
UPPER 70S AND LOWER 80S. LOWS TONIGHT SHOULD DROP TO THE LOWER AND
MID 60S AS DRIER AIR WORKS ITS WAY IN FROM THE NORTHWEST BEHIND THE
COLD FRONT. SOME PATCHY FOG COULD DEVELOP LATE TONIGHT...BUT OVERALL
THE ATMOSPHERE WILL BE DRYING OUT.
SATURDAY LOOKS LIKE A DECENT DAY WITH A FAIR AMOUNT OF SUNSHINE AND
HIGHS IN THE 80S. CLOUDS WILL START TO INCREASE SATURDAY NIGHT...
ESPECIALLY IN OUR FAR WESTERN ZONES. KEPT A SMALL CHANCE OF LATE
NIGHT TSTMS IN NORTHEAST NEBRASKA.
MODELS HAVE SOME TIMING DIFFERENCES FOR SUNDAY INTO SUNDAY NIGHT.
KEPT SOME LOW POPS LATE SATURDAY NIGHT WEST OF A LINE FROM WAYNE TO
COLUMBUS. 00Z RUNS OF THE NAM AND CANADIAN MODEL WERE A BIT SLOWER
WITH DEVELOPMENT OF STORMS SUNDAY AFTERNOON. FOR NOW...BLENDED IN
SOME OF THE GFS AND ECMWF WHICH SHOW SOME RAINFALL AMOUNTS OVER A
QUARTER OF AN INCH SUNDAY AFTERNOON. IF THE NAM IS MORE CORRECT...
THE SEVERE WEATHER POTENTIAL IS PROBABLY HIGHER SUNDAY EVENING THAN
IF THE GFS AND ECMWF VERIFY BETTER. LOOK FOR HIGHS MAINLY IN THE
80S AND MAYBE NEAR 90 FOR PARTS OF SOUTHEAST NEBRASKA.
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 325 AM CDT FRI AUG 29 2014
TRENDED POPS DOWNWARD SUNDAY NIGHT FROM NORTHWEST TO SOUTHEAST AS
THE SYSTEM MOVES THROUGH...BUT LINGERED A SLIGHT CHANCE OF TSTMS
INTO MONDAY MORNING.
A 500 MB LONGWAVE TROUGH AXIS WILL BE LOCATED OVER THE EASTERN
ROCKIES AND WESTERN HIGH PLAINS AT THE BEGINNING OF THIS PERIOD.
BY TUESDAY...THAT SHIFTS EAST OF OUR AREA AND THEN THE FLOW IS
FAIRLY ZONAL ACROSS MID AMERICA INTO WEDNESDAY. LATER IN THE WEEK
ANOTHER TROUGH WILL DIG INTO THE PACIFIC NORTHWEST...WITH OUR
AREA UNDER THE INFLUENCE OF SOUTHWEST MID LEVEL FLOW. ALTHOUGH
THUNDERSTORM CHANCES WILL NOT BE COMPLETELY ABSENT...NEXT WEEK
SHOULD BE A LOT DRIER THAN THIS WEEK HAS BEEN. HIGHS WILL MODERATE
FROM MAINLY 80S TO AROUND 90 AND LOWS WILL INCREASE FROM 60S TO
AROUND 70 OR THE LOWER 70S.
&&
.AVIATION...(12Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 624 AM CDT FRI AUG 29 2014
LATEST OBS SHOWING MID LVL CIGS PREVAILING OVER ERN NEB THIS
MORNING WITH -SHRA MOVING NWD OUT OF ERN KS. EXPECT ACTIVITY WILL
DIMINISH WITHIN THE NEXT COUPLE HOURS...THUS HAVE ADDED TEMPO
GROUPS TO KOMA/KLNK. MEANWHILE...A STALLED FRONTAL BNDRY
EXTENDING FROM NW IA TO CNTRL KS WILL BE THE FOCUS FOR CONVECTIVE
REDEVELOPMENT LATE THIS AFTN. AREAL COVERAGE IS IN QUESTION AT
THIS POINT...THUS OPTED FOR PROB30 GROUPS. VFR CONDITIONS THEN
DURING THE EVENING AND OVERNIGHT HOURS.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...MILLER
LONG TERM...MILLER
AVIATION...DEE
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
325 AM CDT FRI AUG 29 2014
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 325 AM CDT FRI AUG 29 2014
THE PRIMARY FORECAST CHALLENGES WILL BE IN REGARDS TO PCPN CHANCES
TODAY INTO TONIGHT AND THEN TIMING THE NEXT ROUND OF CONVECTION
SUNDAY INTO SUNDAY NIGHT. SOME SEVERE STORMS WILL BE POSSIBLE MAINLY
FROM SUNDAY AFTERNOON THROUGH SUNDAY EVENING.
MAIN FEATURES FROM THE UPPER AIR CHARTS LAST EVENING INCLUDED THE
FOLLOWING. AT 300 MB A JET SEGMENT OF AROUND 70 KNOTS WAS PUNCHING
NORTHEAST FROM SOUTHWEST KS. THIS WAS AHEAD OF A 500 MB TROUGH THAT
STRETCHED FROM THE DAKOTAS DOWN INTO WEST TEXAS. 12 HOUR HEIGHT
FALLS OF UP TO AROUND 40 METERS WERE NOTED AT AMARILLO AND DODGE
CITY. DECENT MOISTURE WAS STILL IN PLACE AT 700 MB AND 850 MB AHEAD
OF THE MID LEVEL TROUGH. THE KOAX SOUNDING WAS STILL FAIRLY MOIST
WITH 1.70 PRECIPITABLE WATER.
SURFACE ANALYSIS AT 08Z SHOWED LOW PRESSURE CENTERED OVER SOUTHEAST
SOUTH DAKOTA AND A COLD FRONT EXTENDING SOUTHWARD FROM THE LOW INTO
WEST TEXAS. DEWPOINTS WERE IN THE 60S TO LOWER 70S.
WATER VAPOR LOOP EARLY THIS MORNING SHOWED THAT THE TROUGH TO OUR
WEST HAD MADE SOME EASTWARD PROGRESS SINCE LAST EVENING. IT SHOULD
CONTINUE TO HAVE AN IMPACT ON US UNTIL A LITTLE AFTER MIDNIGHT
TONIGHT. KEPT FAIRLY HIGH POPS GOING TODAY...SINCE WE SHOULD SEE
REDEVELOPMENT THIS AFTERNOON WITH DAYTIME HEATING. FORECAST
SOUNDINGS FROM THE 00Z NAM INDICATED ELEVATED INSTABILITY OF OVER
2000 J/KG BY AROUND NOON. RECENT RUNS OF THE RAP MODEL SHOW AN
INCREASE IN PCPN COVERAGE AFTER 1 PM. HIGHS WILL BE MAINLY IN THE
UPPER 70S AND LOWER 80S. LOWS TONIGHT SHOULD DROP TO THE LOWER AND
MID 60S AS DRIER AIR WORKS ITS WAY IN FROM THE NORTHWEST BEHIND THE
COLD FRONT. SOME PATCHY FOG COULD DEVELOP LATE TONIGHT...BUT OVERALL
THE ATMOSPHERE WILL BE DRYING OUT.
SATURDAY LOOKS LIKE A DECENT DAY WITH A FAIR AMOUNT OF SUNSHINE AND
HIGHS IN THE 80S. CLOUDS WILL START TO INCREASE SATURDAY NIGHT...
ESPECIALLY IN OUR FAR WESTERN ZONES. KEPT A SMALL CHANCE OF LATE
NIGHT TSTMS IN NORTHEAST NEBRASKA.
MODELS HAVE SOME TIMING DIFFERENCES FOR SUNDAY INTO SUNDAY NIGHT.
KEPT SOME LOW POPS LATE SATURDAY NIGHT WEST OF A LINE FROM WAYNE TO
COLUMBUS. 00Z RUNS OF THE NAM AND CANADIAN MODEL WERE A BIT SLOWER
WITH DEVELOPMENT OF STORMS SUNDAY AFTERNOON. FOR NOW...BLENDED IN
SOME OF THE GFS AND ECMWF WHICH SHOW SOME RAINFALL AMOUNTS OVER A
QUARTER OF AN INCH SUNDAY AFTERNOON. IF THE NAM IS MORE CORRECT...
THE SEVERE WEATHER POTENTIAL IS PROBABLY HIGHER SUNDAY EVENING THAN
IF THE GFS AND ECMWF VERIFY BETTER. LOOK FOR HIGHS MAINLY IN THE
80S AND MAYBE NEAR 90 FOR PARTS OF SOUTHEAST NEBRASKA.
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 325 AM CDT FRI AUG 29 2014
TRENDED POPS DOWNWARD SUNDAY NIGHT FROM NORTHWEST TO SOUTHEAST AS
THE SYSTEM MOVES THROUGH...BUT LINGERED A SLIGHT CHANCE OF TSTMS
INTO MONDAY MORNING.
A 500 MB LONGWAVE TROUGH AXIS WILL BE LOCATED OVER THE EASTERN
ROCKIES AND WESTERN HIGH PLAINS AT THE BEGINNING OF THIS PERIOD.
BY TUESDAY...THAT SHIFTS EAST OF OUR AREA AND THEN THE FLOW IS
FAIRLY ZONAL ACROSS MID AMERICA INTO WEDNESDAY. LATER IN THE WEEK
ANOTHER TROUGH WILL DIG INTO THE PACIFIC NORTHWEST...WITH OUR
AREA UNDER THE INFLUENCE OF SOUTHWEST MID LEVEL FLOW. ALTHOUGH
THUNDERSTORM CHANCES WILL NOT BE COMPLETELY ABSENT...NEXT WEEK
SHOULD BE A LOT DRIER THAN THIS WEEK HAS BEEN. HIGHS WILL MODERATE
FROM MAINLY 80S TO AROUND 90 AND LOWS WILL INCREASE FROM 60S TO
AROUND 70 OR THE LOWER 70S.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1137 PM CDT THU AUG 28 2014
CONVECTION AROUND OR DEVELOPING IN THE AREA WILL AFFECT KOFK
THROUGH ABOUT 08Z...KLNK THROUGH ABOUT 10Z...AND KOMA 08-12Z.
OTHERWISE...VFR CONDITIONS EARLY IN THE PERIOD...BUT COULD SEE
TEMPORARY MVFR CONDITIONS AT ALL THREE TAF SITES 10-15Z...WITH
TEMPORARY IFR CONDITIONS POSSIBLE AT KOFK. COULD ALSO SEE AN
ADDITIONAL 30 PERCENT CHANCE OF OF SHOWERS/THUNDERSTORMS AT
KLNK/KOMA 16-22Z. WEAK WIND SHIFT FROM SOUTHEAST TO NORTHWEST
THROUGH THE PERIOD AS WELL.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...MILLER
LONG TERM...MILLER
AVIATION...DEWALD
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1257 AM CDT FRI AUG 29 2014
.SHORT TERM...(THIS EVENING THROUGH TONIGHT)
ISSUED AT 309 PM CDT THU AUG 28 2014
THE PRIMARY FORECAST CONCERN THROUGH TONIGHT WILL ONCE AGAIN
CENTER AROUND THE CHANCE OF THUNDERSTORMS...LOCALLY HEAVY
RAINFALL...AND POSSIBLE FLOODING. SHOWERS AND THUNDERSTORMS SHOULD
BE LESS WIDESPREAD AND OVERALL LESS HEAVY THAN WHAT WE SAW LAST
NIGHT. THE PRIMARY TRIGGERING MECHANISM CONTINUES TO BE AN UPPER
LEVEL TROUGH THAT HAS VERY SLOWLY BEEN SLIDING EAST ACROSS
NEBRASKA. THE 500 MB TROUGH AXIS WILL EVENTUALLY SLIDE EAST INTO
OUR CWA BY DAWN. AS LONG AS WE ARE OUT AHEAD OF THIS TROUGH AXIS
WE WILL SEE AT LEAST SOME CHANCE OF SHOWERS AND
THUNDERSTORMS...WHICH WILL BE THE CASE THROUGH THE NIGHT.
THE 18Z NAM AND A RUN OR TWO OF THE HRRR ARE NOW HINTING AT THE
POSSIBILITY OF SOME ELEVATED THUNDERSTORMS FORMING WITHIN A FEW
HOURS AFTER SUNSET AROUND HIGHWAY 281 OR A LITTLE EAST OF HIGHWAY
281. IF THESE STORMS FORM THEY WILL TRACK NORTHEAST AND COULD BE
HEAVY RAIN PRODUCERS WITH AN OUTSIDE CHANCE OF A LOW END SEVERE
HAIL OR WIND EVENT. INSTABILITY HAS BEEN RATHER LOW TODAY DUE TO
THE EXTENSIVE CLOUD COVER...WHICH IS THE PRIMARY LIMITING FACTOR
FOR SEVERE POTENTIAL. IN ADDITION...THE DEEP LAYER WIND SHEAR IS
ONLY AROUND 30 KTS...WHICH IS WEAK TO MODEST AND CERTAINLY NOT
OVERLY IMPRESSIVE FOR SEVERE POTENTIAL. THEREFORE...GIVEN A FAIRLY
SIMILAR MOIST ENVIRONMENT TO LAST NIGHT BEING LOCATED OUT AHEAD OF
THE UPPER TROUGH...WITH JUST A BIT LESS LIFT OUR PRIMARY CONCERN
WILL REALLY CONTINUE TO BE HEAVY RAIN...BUT JUST LIKELY NOT AS
WIDESPREAD AS THE OTHER NIGHT. THE GROUND IS VERY SATURATED ACROSS
PRETTY MUCH OUR ENTIRE FORECAST AREA SO ANY HEAVY RAIN WILL RESULT
IN RUNOFF AND POSSIBLE FLOODING. AM MOST CONCERNED FOR THE AREA
ALONG AND EAST OF HIGHWAY 281 BASED ON THE LATEST 18Z NAM.
OVERALL...THE PROBABILITY OF RAIN IS LOWER TONIGHT THAN LAST
NIGHT GIVEN THAT THE COVERAGE AREA WILL BE LESS AND IT IS HARD TO
PIN POINT EXACTLY WHERE THE THUNDERSTORMS WILL DEVELOP WITHIN THE
MORE BROAD FAVORABLE ZONE.
.LONG TERM...(FRIDAY THROUGH THURSDAY)
ISSUED AT 309 PM CDT THU AUG 28 2014
FORECAST FOCUS IS ON THE CHANCES OF STORMS FRIDAY AND THEN CHANCES
OF SEVERE STORMS ON SUNDAY.
MODELS ARE IN GOOD AGREEMENT WITH MOVING AND TIMING OF MAJOR
FEATURES AT LEAST THROUGH MONDAY. IN GENERAL THE ATMOSPHERE IS
FORECAST TO MORPH FROM A CUTOFF LOW PATTERN BACK TO A MORE ZONAL
FLOW...SO OUT OF A HEAVY RAIN PATTERN AND BACK INTO A SEVERE WEATHER
TYPE REGIME.
THE LOW PRESSURE AREA THAT HAD BEEN PARKED OVER THE CENTRAL ROCKIES
THE LAST SEVERAL DAYS WILL EJECT EASTWARD ON FRIDAY AND LEAVE DRY
WEATHER BEHIND. AS IT MOVES THROUGH THERE WILL BE A THREAT OF
STORMS...BUT MAINLY OVER THE EASTERN THIRD OF THE AREA ON FRIDAY
AFTERNOON AND EARLY EVENING.
A RIDGE BUILDS OVER THE AREA ON SATURDAY BRINGING THE FIRST DRY AND
WARM DAY IN QUITE A WHILE. LOW CHANCES OF STORMS ARE BACK IN THE
FORECAST FOR SATURDAY NIGHT AND SUNDAY MORNING WITH A WEAK WAVE
MOVING ACROSS THE AREA.
HOWEVER...THE CHANCE OF STORMS FROM MID DAY SUNDAY INTO THE EVENING
IS MORE IMPRESSIVE. A COLD FRONT AND FAIRLY STRONG MID LEVEL WAVE
MOVE THROUGH DURING THAT TIME FRAME. MOST MODELS ARE IN AGREEMENT
WITH THE THE TIMING AN STRENGTH OF THE SYSTEM. THE STRONG
INSTABILITY AND GOOD SHEAR ARE MORE COMMON FOR MAY THAN AUGUST. SO
THERE IS A THREAT OF DAMAGING WINDS AND LARGE HAIL WITH STORMS THAT
DEVELOP. AS WITH ANY FORECAST OF CONVECTION SO MANY DAYS OUT THE
MODELS WILL LIKELY CHANGE...SO WE WILL CONTINUE TO MONITOR IT.
AS FOR THE WORK WEEK (MONDAY THROUGH THURSDAY)...OVERALL...MUCH
DRIER THAN THIS LAST WEEK...BUT HARD TO RULE OUT A HIT AND MISS
AFTERNOON AND EVENING STORM ESPECIALLY MONDAY...BUT THE MODELS ARE
STILL WAFFLING WITH TIMING AND STRENGTH OF FEATURES SO WILL LEAVE
DRY OR LOW PROBABILITIES UNTIL OUR CONFIDENCE RISES MORE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1252 AM CDT FRI AUG 29 2014
VFR CONDITIONS ARE FORECAST. WIND WILL REMAIN LIGHT AND SKY COVER
WILL REMAIN MID-HIGH LEVEL. DISCOUNTING FOG AND STRATUS ADVERTISED
BY THE NAM NUMERICAL MODEL. WE COULD GET A THUNDERSHOWER DURING
THE DAY FRIDAY ASSOCIATED WITH A PASSING TROUGH AXIS...BUT CHANCES
ARE FAIRLY LOW AND TIMING IS DIFFICULT TO DETERMINE.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...WESELY
LONG TERM...EDDY
AVIATION...HEINLEIN
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
959 PM EDT SAT AUG 30 2014
.SYNOPSIS...
EXPECT AN INCREASING CHANCE OF SHOWERS AND A FEW THUNDERSTORMS
TONIGHT AND ESPECIALLY ON SUNDAY AS WEAK LOW PRESSURE CROSSES THE
REGION. AFTER A MAINLY DRY DAY ON MONDAY...SHOWERS AND
THUNDERSTORMS RETURN IN EARNEST BY TUESDAY AS A MORE DEFINITIVE
SURFACE FRONT MAKES ITS WAY INTO THE REGION. TEMPERATURES WILL
REMAIN WARM THROUGH TUESDAY...THEN COOL BACK TO LATE SUMMER
SEASONAL NORMALS BEHIND THE FRONT BY MID TO LATE WEEK.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 950 PM EDT SATURDAY...1ST LINE OF SHOWERS DISSIPATED ACRS
CENTRAL ST LAWRENCE COUNTY EARLIER THIS EVENING...BUT ADDITIONAL
SHOWERS WITH EMBEDDED LIGHTNING ARE LOCATED NEAR WATERTOWN NY.
THESE WL IMPACT THE SAME AREAS OF SLV BTWN 1030 AND
MIDNIGHT...BEFORE DISSIPATING ACRS THE NORTHERN DACKS AFT
MIDNIGHT. THE HRRR AND LOCAL 4KM SHOWS ADDITIONAL SHOWERS
REDEVELOPING INTO A BROKEN LINE AFT MIDNIGHT AND IMPACTING THE CPV
BTWN 09-12Z...BEFORE SHIFTING INTO CENTRAL/EASTERN VT. WL CONT TO
MENTION CHC POPS THRU MIDNIGHT AND INCREASE TO LIKELY FROM WEST TO
EAST AFT MIDNIGHT TO COVER BETTER AREAL COVERAGE OF PRECIP. HAVE
NOTED LLVL JET INCREASING ACRS OUR REGION WITH CXX 925MB WINDS OF
30 TO 35 KNOTS...BUT MIXING TO THE SFC HAS ONLY OCCURRED OVER THE
WARMER LAKE CHAMPLAIN WATERS. THINKING A FEW GUSTS BTWN 20 AND 25
KNOTS ARE POSSIBLE IN THE CPV OVERNIGHT...GIVEN STRENGTH OF JET.
OTHERWISE...TEMPS WL RANGE FROM THE U50S NEK TO U60S
CPV/SLV...WITH MAYBE A FEW UHI AREAS NEAR 70F FOR AN OVERNIGHT.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
AS OF 330 PM EDT SATURDAY...MOST INCLEMENT WEATHER IN THE SHORT
TERM THEN OCCURS ON SUNDAY INTO SUNDAY EVENING AS AFOREMENTIONED
TROUGH SWINGS THROUGH THE AREA ALONG WITH NUMEROUS SHOWERS/STORMS.
NEGLIGIBLE BAROCLINICITY ACROSS THE BOUNDARY COMBINED WITH PLENTY
OF CLOUDS AND LIMITED INSTABILITY SHOULD KEEP ANY ENHANCED SVR
THREAT AT A MINIMUM...BUT WE COULD SEE A FEW STRONGER CELLS ACROSS
OUR FAR SRN VT COUNTIES WHERE SOME MORNING SUN WILL BE POSSIBLE.
GUSTY WINDS WOULD BE THE PRIMARY THREAT IF ANYTHING WOULD DEVELOP.
OTHERWISE EXPECT A GENERALLY CLOUDY AND OCCASIONALLY WET DAY AS
SHOWERS/SCT GARDEN-VARIETY STORMS TRAVERSE THE REGION. NARROW PWAT
AXIS OF 1.7-1.9 INCHES WILL EXIST ALONG AND JUST AHEAD OF THE
BOUNDARY SO SOME BRIEF HEAVIER DOWNPOURS ARE CERTAINLY POSSIBLE.
HOWEVER MEAN STORM MOVEMENT OF 15 TO 20 MPH SHOULD LIMIT ANY
HYDROLOGICAL CONCERNS. HIGHS MAINLY IN THE 70S GIVEN THE AMPLE
CLOUDS.
EVENING SHOWERS/STORMS THEN EXIT EAST THROUGH THE EVENING HOURS ON
SUNDAY AS TROUGH CLEARS THE AREA LEAVING VARIABLY CLOUDY SKIES
OVERNIGHT. COULD SEE SOME PATCHY FOG HERE AND THERE BUT LOW LEVEL
WIND FIELDS HIGH ENOUGH THAT IT SHOULD BE MORE CONFINED TO MOST
FAVORED CLIMATOLOGICAL AREAS. AS MENTIONED ABOVE...LITTLE AIRMASS
CHANGE BEHIND THE BOUNDARY...SO LOWS GENERALLY IN THE 60S
EXPECTED...PERHAPS A FEW UPPER 50S IN COOLER NRN MTN LOCALES.
BY MONDAY WEAK SHORTWAVE RIDGING DEVELOPS BETWEEN DEPARTING TROUGH
AND A MORE SUBSTANTIAL UPPER TROUGH DIGGING ACROSS THE GREAT LAKES
STATES TO OUR WEST. CAN`T COMPLETELY RULE OUT AN ISOLATED
SHOWER/STORM JUST ABOUT ANYWHERE WITH SOME LINGERING MOISTURE AND
PBL INSTABILITY OF 200-600 J/KG...BUT MOST LOCALES SHOULD REMAIN
LARGELY DRY WITH LACK OF LARGE-SCALE FORCING. BLENDED 18Z 925MB
THERMAL PROFILES SUGGEST HIGHS FROM 77 TO 83 OR SO UNDER PARTIAL
SUNSHINE...WARMEST IN THE BROADER VALLEYS.
THEN PARTLY CLOUDY AND CONTINUED MAINLY DRY MONDAY NIGHT AS
SOUTHERLY FLOW SLOWLY INCREASES ONCE AGAIN AHEAD OF APPROACHING
UPPER TROUGH AND ATTENDANT SFC BOUNDARY TO OUR WEST. WILL CONTINUE
PRIOR IDEA OF LOWER CHANCES FOR SHOWERS/STORMS ACROSS OUR
WESTERNMOST NY COUNTIES OVERNIGHT IN CLOSER PROXIMITY TO THE
BOUNDARY AND BETTER DYNAMICAL FORCING. MAINLY DRY FURTHER EAST INTO
VERMONT HOWEVER. TEMPERATURES REMAIN ON THE MILD SIDE...GENERALLY IN
THE 60S.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 341 PM EDT SATURDAY...THIS LONG TERM PERIOD LOOKS VERY CONSISTENT
TO PREVIOUS FCST.
THE MAIN WEATHER CONCERN DURING THIS LONG TERM PERIOD WILL BE TUESDAY
AND TUESDAY NIGHT. UPPER LEVEL TROUGH AND ITS ASSOCIATED COLD
FRONT WILL BE MOVING INTO THE AREA DURING THE AFTERNOON AND
EVENING HOURS. AHEAD OF THE FRONT...ABOVE NORMAL TEMPERATURES ARE
EXPECTED WITH HIGHS IN THE 80S AND COMBINED WITH INCREASING DEW
POINTS...SUFFICIENT INSTABILITY WILL DEVELOP OVER THE AREA AHEAD
OF THE FRONT. DEEP LAYER SHEAR WILL ALSO BE INCREASING OVER THIS
AREA OF DEVELOPING INSTABILITY. ALL OF THIS SUGGESTS THE POTENTIAL
FOR THUNDERSTORMS...SOME OF WHICH COULD BE STRONG OR SEVERE. THUS
WILL HAVE TO KEEP AN EYE ON THIS SYSTEM.
THEREAFTER...FRONT EXITS THE AREA BY EARLY WED MRNG AND UPPER LEVEL
FLOW FOR THE REMAINDER OF THE WEEK QUICKLY RETURNS TO ZONAL FLOW ON
NORTHERN PERIPERHY OF SOUTHEAST CONUS RIDGE. THEREFORE...PRETTY MUCH
DRIER AIR BUT AOA SEASONABLE TEMPS CONTINUE BEFORE ANOTHER NRN
STREAM SHORTWAVE...THIS ONE FURTHER NORTH...MOVES ACROSS QUEBEC
WITH A SURFACE FRONT IN THE FRI NGT-SAT TIMEFRAME. HIGH TEMPS IN THE
M-U70S TO L80S.
&&
.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
THROUGH 00Z MONDAY...OVERALL LOOKING AT VFR CONDITIONS THROUGH
MOST OF THE PERIOD. MAINLY MID AND HIGH LEVEL CLOUDS THROUGH THE
EVENING...THEN CEILINGS BEGIN TO LOWER OVERNIGHT TO BROKEN TO
OVERCAST CEILINGS AROUND 5000 FEET ARD/AFT 09Z SUNDAY SPREADING
EAST. THERE WILL ALSO BE SOME LIGHT SHOWERS MOVING FROM WEST TO
EAST BETWEEN 06Z AND 12Z...BUT VISIBILITIES WILL REMAIN
UNRESTRICTED.
SHOWERS BECOME MORE NUMEROUS AND LOCALLY HEAVY DUE TO HIGH
PRECIPITABLE WATERS DURING THE DAY ON SUNDAY. THUS...ANY SHOWERS
MAY HAVE BRIEF MVFR-IFR IN VSBY DUE TO RAINFALL INTENSITY WITH
AREAS OF MVFR CIGS LIKELY FOR MOST OF SUNDAY.
SURFACE WINDS WILL BE LIGHTER THAN TODAY...AROUND 10 KNOTS FROM
THE SOUTH AND SOUTH AND SOUTHWEST.
OUTLOOK 00Z MONDAY THROUGH THURSDAY...
00Z MONDAY ONWARD...MAINLY VFR, THOUGH MVFR/BRIEF IFR IN
SCATTERED SHOWERS AND THUNDERSTORMS THAT WILL BE MOST NUMEROUS
SUNDAY AND PERHAPS AGAIN LATE TUESDAY. VFR EXPECTED WEDNESDAY AND
THURSDAY AS A RIDGE OF HIGH PRESSURE WILL BE OVER THE REGION.
&&
.MARINE...
AS OF 300 PM EDT SATURDAY...SOUTH WINDS OF 15 TO 25 KNOTS WILL
CONTINUE THROUGH THE REMAINDER OF TODAY...TONIGHT...AND INTO
SUNDAY MORNING. GUSTS WILL REACH 30 KNOTS AT TIMES. THUS A LAKE
WIND ADVISORY REMAINS IN EFFECT. THESE WINDS WILL CREATE WAVES OF
2 TO 4 FEET...WITH THE HIGHEST WAVES IN THE OPEN WATERS OF THE
CENTRAL AND NORTHERN PORTIONS OF THE LAKE. BY SUNDAY
AFTERNOON...SOUTH WINDS WILL TAPER OFF TO 10 TO 20 KNOTS AND WAVES
WILL SUBSIDE TO 1 TO 3 FEET. WIDESPREAD SHOWERS AND THUNDERSTORMS
WILL ALSO DEVELOP ON SUNDAY.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JMG
NEAR TERM...JMG/TABER
SHORT TERM...JMG
LONG TERM...EVENSON/SLW
AVIATION...WGH/SLW
MARINE...WFO BTV
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
816 PM EDT SAT AUG 30 2014
.SYNOPSIS...
EXPECT AN INCREASING CHANCE OF SHOWERS AND A FEW THUNDERSTORMS
TONIGHT AND ESPECIALLY ON SUNDAY AS WEAK LOW PRESSURE CROSSES THE
REGION. AFTER A MAINLY DRY DAY ON MONDAY...SHOWERS AND
THUNDERSTORMS RETURN IN EARNEST BY TUESDAY AS A MORE DEFINITIVE
SURFACE FRONT MAKES ITS WAY INTO THE REGION. TEMPERATURES WILL
REMAIN WARM THROUGH TUESDAY...THEN COOL BACK TO LATE SUMMER
SEASONAL NORMALS BEHIND THE FRONT BY MID TO LATE WEEK.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 643 PM EDT SATURDAY...EARLY UPDATE TO FCST THIS EVENING TO
INCREASE POPS ACRS THE SLV. CRNT RADAR SHOWS A CLUSTER OF SHOWERS
WITH EMBEDDED THUNDERSTORMS DEVELOPING OVER CENTRAL LAKE ONTARIO.
USING THE TIME OF ARRIVAL TOOL...PLACES THIS ACTIVITY ACRS EXTREME
SOUTHWEST ST LAWRENCE COUNTY AROUND 00Z AND INTO THE CENTRAL
PORTION OF THE COUNTY BY 01Z. LATEST 21Z HRRR MODELS SEEMS TO BE
HANDLING PRECIP THE BEST AND SHOWS THIS AREA QUICKLY TRACKING
NORTHEAST INTO THE SLV...BUT WEAKENING AS BEST INSTABILITY IS
LOCATED ACRS WESTERN NY. WL MENTION CHC POPS WITH THIS SECONDARY
WARM FRNT AND ASSOCIATED LLVL JET. THESE SHOWERS WL RESULT IN A
JUMP IN SFC DWPTS...ESPECIALLY ACRS THE SLV/NORTHERN NY
TONIGHT...WITH THIS BOUNDARY LIFTING INTO THE CPV AFT 06Z.
THINKING ADDITIONAL SHOWERS COULD DEVELOP AFT MIDNIGHT ACRS
NORTHERN NY AND MOVE INTO THE CPV TWD 09Z. THIS IS ALL COVERED IN
CRNT FCST WITH CHC POPS...INCREASING TO LIKELY TOWARD DAY BREAK.
INSTABILITY IS MARGINAL AND ELEVATED ASSOCIATED WITH LLVL JET...SO
ONLY SCHC FOR THUNDER OVERNIGHT INTO EARLY SUNDAY MORNING. TEMPS
WL HOLD IN THE U50S NEK TO U60S SLV/CPV...ASSOCIATED WITH
INCREASED DWPTS AND GUSTY SOUTHERLY WINDS. THE HUMIDITY WL CONT TO
INCREASE OVERNIGHT INTO SUNDAY...ESPECIALLY IN THE CPV. EXPECT IT
TO FEEL PRETTY HUMID BY MIDDAY SUNDAY...ACRS MOST OF THE REGION.
PREVIOUS DISCUSSION FOLLOWS...
SOUTHERLY FLOW WILL CONTINUE THIS EVENING/TONIGHT AS HIGH PRESSURE
DEPARTS OFFSHORE AND A DAMPENING SFC TO MID LEVEL TROUGH PUSHES
EAST FROM THE GREAT LAKES/OHIO VALLEY. SCATTERED SHOWERS AND/OR
ISOLATED STORMS WILL BE POSSIBLE LATER THIS EVENING AND
TONIGHT...ESPECIALLY ACROSS OUR NRN NY COUNTIES WHERE SLIGHT H5
HEIGHT FALLS...INCREASING MOISTURE RETURN AND SOME MID LEVEL
INSTABILITY WILL BE PRESENT. TEMPERATURES TO HOLD ON THE MILD SIDE
(60S) AS CLOUDS SLOWLY INCREASE THROUGH TIME...ESPECIALLY IN THE
ST LAWRENCE AND CHAMPLAIN VALLEYS WHERE NOCTURNAL SOUTHERLY LLJ
DEVELOPMENT IS EXPECTED NEAR THE 925 MB LEVEL.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
AS OF 330 PM EDT SATURDAY...MOST INCLEMENT WEATHER IN THE SHORT
TERM THEN OCCURS ON SUNDAY INTO SUNDAY EVENING AS AFOREMENTIONED
TROUGH SWINGS THROUGH THE AREA ALONG WITH NUMEROUS SHOWERS/STORMS.
NEGLIGIBLE BAROCLINICITY ACROSS THE BOUNDARY COMBINED WITH PLENTY
OF CLOUDS AND LIMITED INSTABILITY SHOULD KEEP ANY ENHANCED SVR
THREAT AT A MINIMUM...BUT WE COULD SEE A FEW STRONGER CELLS ACROSS
OUR FAR SRN VT COUNTIES WHERE SOME MORNING SUN WILL BE POSSIBLE.
GUSTY WINDS WOULD BE THE PRIMARY THREAT IF ANYTHING WOULD DEVELOP.
OTHERWISE EXPECT A GENERALLY CLOUDY AND OCCASIONALLY WET DAY AS
SHOWERS/SCT GARDEN-VARIETY STORMS TRAVERSE THE REGION. NARROW PWAT
AXIS OF 1.7-1.9 INCHES WILL EXIST ALONG AND JUST AHEAD OF THE
BOUNDARY SO SOME BRIEF HEAVIER DOWNPOURS ARE CERTAINLY POSSIBLE.
HOWEVER MEAN STORM MOVEMENT OF 15 TO 20 MPH SHOULD LIMIT ANY
HYDROLOGICAL CONCERNS. HIGHS MAINLY IN THE 70S GIVEN THE AMPLE
CLOUDS.
EVENING SHOWERS/STORMS THEN EXIT EAST THROUGH THE EVENING HOURS ON
SUNDAY AS TROUGH CLEARS THE AREA LEAVING VARIABLY CLOUDY SKIES
OVERNIGHT. COULD SEE SOME PATCHY FOG HERE AND THERE BUT LOW LEVEL
WIND FIELDS HIGH ENOUGH THAT IT SHOULD BE MORE CONFINED TO MOST
FAVORED CLIMATOLOGICAL AREAS. AS MENTIONED ABOVE...LITTLE AIRMASS
CHANGE BEHIND THE BOUNDARY...SO LOWS GENERALLY IN THE 60S
EXPECTED...PERHAPS A FEW UPPER 50S IN COOLER NRN MTN LOCALES.
BY MONDAY WEAK SHORTWAVE RIDGING DEVELOPS BETWEEN DEPARTING TROUGH
AND A MORE SUBSTANTIAL UPPER TROUGH DIGGING ACROSS THE GREAT LAKES
STATES TO OUR WEST. CAN`T COMPLETELY RULE OUT AN ISOLATED
SHOWER/STORM JUST ABOUT ANYWHERE WITH SOME LINGERING MOISTURE AND
PBL INSTABILITY OF 200-600 J/KG...BUT MOST LOCALES SHOULD REMAIN
LARGELY DRY WITH LACK OF LARGE-SCALE FORCING. BLENDED 18Z 925MB
THERMAL PROFILES SUGGEST HIGHS FROM 77 TO 83 OR SO UNDER PARTIAL
SUNSHINE...WARMEST IN THE BROADER VALLEYS.
THEN PARTLY CLOUDY AND CONTINUED MAINLY DRY MONDAY NIGHT AS
SOUTHERLY FLOW SLOWLY INCREASES ONCE AGAIN AHEAD OF APPROACHING
UPPER TROUGH AND ATTENDANT SFC BOUNDARY TO OUR WEST. WILL CONTINUE
PRIOR IDEA OF LOWER CHANCES FOR SHOWERS/STORMS ACROSS OUR
WESTERNMOST NY COUNTIES OVERNIGHT IN CLOSER PROXIMITY TO THE
BOUNDARY AND BETTER DYNAMICAL FORCING. MAINLY DRY FURTHER EAST INTO
VERMONT HOWEVER. TEMPERATURES REMAIN ON THE MILD SIDE...GENERALLY IN
THE 60S.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 341 PM EDT SATURDAY...THIS LONG TERM PERIOD LOOKS VERY CONSISTENT
TO PREVIOUS FCST.
THE MAIN WEATHER CONCERN DURING THIS LONG TERM PERIOD WILL BE TUESDAY
AND TUESDAY NIGHT. UPPER LEVEL TROUGH AND ITS ASSOCIATED COLD
FRONT WILL BE MOVING INTO THE AREA DURING THE AFTERNOON AND
EVENING HOURS. AHEAD OF THE FRONT...ABOVE NORMAL TEMPERATURES ARE
EXPECTED WITH HIGHS IN THE 80S AND COMBINED WITH INCREASING DEW
POINTS...SUFFICIENT INSTABILITY WILL DEVELOP OVER THE AREA AHEAD
OF THE FRONT. DEEP LAYER SHEAR WILL ALSO BE INCREASING OVER THIS
AREA OF DEVELOPING INSTABILITY. ALL OF THIS SUGGESTS THE POTENTIAL
FOR THUNDERSTORMS...SOME OF WHICH COULD BE STRONG OR SEVERE. THUS
WILL HAVE TO KEEP AN EYE ON THIS SYSTEM.
THEREAFTER...FRONT EXITS THE AREA BY EARLY WED MRNG AND UPPER LEVEL
FLOW FOR THE REMAINDER OF THE WEEK QUICKLY RETURNS TO ZONAL FLOW ON
NORTHERN PERIPERHY OF SOUTHEAST CONUS RIDGE. THEREFORE...PRETTY MUCH
DRIER AIR BUT AOA SEASONABLE TEMPS CONTINUE BEFORE ANOTHER NRN
STREAM SHORTWAVE...THIS ONE FURTHER NORTH...MOVES ACROSS QUEBEC
WITH A SURFACE FRONT IN THE FRI NGT-SAT TIMEFRAME. HIGH TEMPS IN THE
M-U70S TO L80S.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
THROUGH 00Z MONDAY...OVERALL LOOKING AT VFR CONDITIONS THROUGH
MOST OF THE PERIOD. MAINLY MID AND HIGH LEVEL CLOUDS THROUGH THE
EVENING...THEN CEILINGS BEGIN TO LOWER OVERNIGHT TO BROKEN TO
OVERCAST CEILINGS AROUND 5000 FEET ARD/AFT 09Z SUNDAY SPREADING
EAST. THERE WILL ALSO BE SOME LIGHT SHOWERS MOVING FROM WEST TO
EAST BETWEEN 06Z AND 12Z...BUT VISIBILITIES WILL REMAIN
UNRESTRICTED.
SHOWERS BECOME MORE NUMEROUS AND LOCALLY HEAVY DUE TO HIGH
PRECIPITABLE WATERS DURING THE DAY ON SUNDAY. THUS...ANY SHOWERS
MAY HAVE BRIEF MVFR-IFR IN VSBY DUE TO RAINFALL INTENSITY WITH
AREAS OF MVFR CIGS LIKELY FOR MOST OF SUNDAY.
SURFACE WINDS WILL BE LIGHTER THAN TODAY...AROUND 10 KNOTS FROM
THE SOUTH AND SOUTH AND SOUTHWEST.
OUTLOOK 00Z MONDAY THROUGH THURSDAY...
00Z MONDAY ONWARD...MAINLY VFR, THOUGH MVFR/BRIEF IFR IN
SCATTERED SHOWERS AND THUNDERSTORMS THAT WILL BE MOST NUMEROUS
SUNDAY AND PERHAPS AGAIN LATE TUESDAY. VFR EXPECTED WEDNESDAY AND
THURSDAY AS A RIDGE OF HIGH PRESSURE WILL BE OVER THE REGION.
&&
.MARINE...
AS OF 300 PM EDT SATURDAY...SOUTH WINDS OF 15 TO 25 KNOTS WILL
CONTINUE THROUGH THE REMAINDER OF TODAY...TONIGHT...AND INTO
SUNDAY MORNING. GUSTS WILL REACH 30 KNOTS AT TIMES. THUS A LAKE
WIND ADVISORY REMAINS IN EFFECT. THESE WINDS WILL CREATE WAVES OF
2 TO 4 FEET...WITH THE HIGHEST WAVES IN THE OPEN WATERS OF THE
CENTRAL AND NORTHERN PORTIONS OF THE LAKE. BY SUNDAY
AFTERNOON...SOUTH WINDS WILL TAPER OFF TO 10 TO 20 KNOTS AND WAVES
WILL SUBSIDE TO 1 TO 3 FEET. WIDESPREAD SHOWERS AND THUNDERSTORMS
WILL ALSO DEVELOP ON SUNDAY.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JMG
NEAR TERM...JMG/TABER
SHORT TERM...JMG
LONG TERM...EVENSON/SLW
AVIATION...WGH/SLW
MARINE...WFO BTV
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
355 PM EDT FRI AUG 29 2014
.SYNOPSIS...
HIGH PRESSURE WILL BRING PLEASANT WEATHER TO OUR AREA TONIGHT
THROUGH SATURDAY. A STORM SYSTEM MOVING THROUGH THE UPPER GREAT
LAKES AND EASTERN CANADA WILL GIVE THE REGION SHOWERS AND
THUNDERSTORMS LATE SATURDAY NIGHT AND SUNDAY. HIGH PRESSURE WILL
PROVIDE PARTLY SUNNY SKIES AND WARM TEMPERATURES ON MONDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
4 PM UPDATE...UPPER LEVEL RIDGE WILL CREST OVER THE REGION TONIGHT
AS SFC HIGH PRES RESIDES OVER EASTERN NEW ENGLAND. PARTLY CLOUDY
SKIES ARE EXPECTED DUE TO SOME MID LEVEL CLOUDINESS. LATE TONIGHT
DUE TO RADIATIONAL COOLING PATCHY VALLEY FOG IS LIKELY IN THE
DELAWARE, SUSQUEHANNA AND CHEMUNG BASINS. OVERNIGHT LOWS WILL
RANGE IN THE LOWER TO MIDDLE 50S.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
SATURDAY...UPPER LEVEL RIDGE AXIS WILL MOVE TO NEW ENGLAND AS AN
UPPER LEVEL TROF DROPS INTO THE UPPER GREAT LAKES. SFC HIGH PRES
OFF THE NEW ENGLAND COAST WILL PROVIDE A MODERATING S/SW FLOW.
PARTLY SUNNY SKIES ARE EXPECTED WITH ANY CONVECTION HOLDING OFF
UNTIL DARK. MAX TEMPS WILL RANGE IN THE MID 70S TO LOWER 80S WITH
THE HIGHEST READINGS ALONG THE LAKE PLAIN AND CENTRAL SOUTHERN TIER.
SATURDAY NIGHT/SUNDAY...UPPER LEVEL TROF WILL APPROACH THE REGION
AS A LOW PRES SYSTEM DRAGS A WEAK SFC TROF THROUGH THE AREA ON
SUNDAY. THE CHANCES FOR PRECIP WILL INCREASE LATE SATURDAY EVENING
AS MID LEVEL SHORT WAVES START ROTATING THROUGH THE AREA IN THE
SOUTHWEST UPPER LEVEL FLOW. BY DAYBREAK SUNDAY WILL HAVE LIKELY
POPS ACROSS MUCH OF CENTRAL NEW YORK AND SLIGHT CHC/CHC NE PA.
AS THIS BOUNDARY SLIDES THROUGH THE REGION WILL ADVERTISE LIKELY
POPS FOR SHOWERS AND THUNDERSTORMS. AIRMASS ON SUNDAY WILL BE
RATHER JUICY WITH PWATS AROUND 2 INCHES INDICATING THE POTENTIAL
FOR HEAVY DOWNPOURS IN ANY CONVECTION. THE SEVERE POTENTIAL LOOKS
MINIMAL AS FRONTAL FORCING IS WEAK ALONG WITH MID LEVEL LAPSE
RATES. DEEP LAYER SHEAR IS FAIRLY HEALTHY ALONG WITH MID LEVEL
WIND FIELDS ALTHOUGH CAPE LOOKS LIMITED DUE TO ABOVE MENTIONED MID
LEVEL LAPSE RATES AND LACK OF SIGNIFICANT HEATING DUE TO EXTENSIVE
CLOUD COVER EXPECTED BY DAYBREAK. WILL CONTINUE TO MONITOR.
SUNDAY NIGHT...INCLUDED LINGERING EVENING ACTIVITY WITH REMAINDER
OF PERIOD DRY AS WAVE PASSES.
MONDAY...BRIEF RIDGING ALOFT AND AT THE SFC WILL PROVIDE A PARTLY
SUNNY DAY WITH MAXES IN THE LOWER TO MIDDLE 80S. WILL CONTINUE
WITH LOW CHC POPS DUE TO CONTINUED MOIST AIRMASS.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
UPR RDG OVER THE ERN U.S. WILL BE FLATTENED BY STRONGER ZONAL FLOW
MOVG INTO THE GTLAKES EARLY NXT WEEK. ASSOCIATED FNTL SYSTEM WILL MOV
THRU THE RGN IN THE TUE/TUE NGT TIME FRAME WITH SHRA/TSRA. HIGH
PRES IS XPCTD TO REBUILD INTO THE AREA BY WED. SOME TIMING DIFFS
AFTER THIS POINT W/RESPECT TO NXT UPSTREAM SYSTEM. WPC GUIDANCE
LOOKED GOOD BUT WE MADE A FEW MINOR ADJUSTMENTS..1) SHOWED MORE IN
THE WAY OF CLDS WITH MIDWEEK FROPA, AND 2) LIMITED POPS TO HI CHC
GIVEN WE`RE STILL SVRL DAYS OUT. SEASONAL TO SLIGHTLY ABV NORMAL
TEMPS.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
VFR WILL PREVAIL FOR THE REMAINDER OF THE AFTN AND INTO THE EVNG
HRS WITH FEW-SCT DIURNAL CU AND SCT-BKN CI. LATER TNGT...PROFILES
FROM THE NAM/GFS SUGGEST ADVECTION/DVLPMNT OF LOWER-LVL STRATUS
INTO PORTIONS OF NE PA AND THE SRN TIER OF NY. RUC AND LCL WRF
PROFILES ARE NOT AS ADAMANT ON THIS DVLPMNT. ATTM SAT PIX SHOW LTL
IN THE WAY OF LOWER CLDS TO OUR S AND SE...SO HEDGED HERE
INDICATING POTNL FOR SCT 1.5-2.5 KFT AT AVP/BGM AFTER 09Z. AT
ELM...A TUFF CALL BUT THINK ANY RESTRICTIONS THERE WOULD BE
RELATED TO VLY FOG/STRATUS FORMATION. VFR TO PREVAIL TMRW AFTER
ANY EARLY MRNG STRICTIONS. WINDS TNGT SELY 5 KTS OR LESS...BECMG
SRLY 10-15 KTS ON SAT.
OUTLOOK...
SATURDAY...PRIMARILY VFR.
SAT NIGHT...PATCHY MVFR LATE IN HZ/BR.
SUN THROUGH TUESDAY...RESTRICTIONS FROM SCT SHRA/TSRA...MAINLY SUNDAY
AND TUESDAY.
WED...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...RRM
NEAR TERM...RRM
SHORT TERM...RRM
LONG TERM...
AVIATION...
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
145 PM EDT FRI AUG 29 2014
.SYNOPSIS...
HIGH PRESSURE WILL BRING FAIR WEATHER TO NY AND PA TODAY. A STORM
SYSTEM WILL MOVE THROUGH NORTHERN NY AND BRING A CHANCE FOR THUNDERSTORMS
SATURDAY NIGHT INTO SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
950 AM UPDATE...LATEST VIS SHOWS MID/HIGH LEVEL CLOUDS ACROSS
WESTERN NY AND INTO THE LAKE PLAIN. EXPECT THIS AREA OF HIGH
CLOUDINESS TO SPREAD ACROSS THE NRN CWA THROUGH MID AFTERNOON IN
AN AREA OF MID LEVEL WARMING. PARTLY SUNNY SKIES ARE STILL
ANTICIPATED ACROSS THE NRN CWA WITH MOSTLY SUNNY SKIES IN THE
CENTRAL/SOUTHERN AREAS. NO OTHER CHANGES.
PREVIOUS DISC...
PATCHY VALLEY FOG WILL BURN OFF BETWEEN 1230 AND 1330Z THIS
MORNING. THEREAFTER HIGH PRESSURE WILL SETTLE IN FOR A SUNNY,
CLEAR WEATHER DAY.
STILL COOL IN THE BOUNDARY LAYER UP TO 850MB SO HAVE RESTRICTED
MAX TEMPS TO THE MID AND UPPER 70S DESPITE NEAR FULL SUN.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
A STORM SYSTEM WILL PULL OUT OF THE GREAT LAKES AND SPREAD
INCREASING MOISTURE INTO NY/PA SATURDAY AFTERNOON INTO SUNDAY.
THERE IS A SLIGHT CHANCE FOR A SHOWER OR THUNDERSTORM OVER THE FAR
WESTERN FA LATE SATURDAY.
FRONT WILL PUSH TOWARD LAKES ERIE AND ONTARIO SATURDAY NIGHT, SO
HAVE ORIENTED POPS FROM NE TO SW. STICKING TO MAINLY CHC/SCT
COVERAGE AS INSTABILITY AND FORCING ARE LACKING. EXPECT FAR SERN
FA TO REMAIN DRY.
SEVERAL HUNDRED JOULES OF CAPE FORECAST FOR SUNDAY AHEAD OF
FRONTAL PUSH. NOT A TON OF INSTABILITY, BUT ENOUGH TO PUSH THE
POPS INTO THE HIGH CHANCE TO LIKELY RANGE. BULK SHEAR VALUES ARE
SUGGESTIVE OF SOME ORGANIZATION (AROUND 30+ KTS) SO WILL NEED TO
KEEP AN EYE ON ISOLATED STRONG CONVECTIVE POTENTIAL.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
UPR RDG OVER THE ERN U.S. WILL BE FLATTENED BY STRONGER ZONAL FLOW
MOVG INTO THE GTLAKES EARLY NXT WEEK. ASSOCIATED FNTL SYSTEM WILL MOV
THRU THE RGN IN THE TUE/TUE NGT TIME FRAME WITH SHRA/TSRA. HIGH
PRES IS XPCTD TO REBUILD INTO THE AREA BY WED. SOME TIMING DIFFS
AFTER THIS POINT W/RESPECT TO NXT UPSTREAM SYSTEM. WPC GUIDANCE
LOOKED GOOD BUT WE MADE A FEW MINOR ADJUSTMENTS..1) SHOWED MORE IN
THE WAY OF CLDS WITH MIDWEEK FROPA, AND 2) LIMITED POPS TO HI CHC
GIVEN WE`RE STILL SVRL DAYS OUT. SEASONAL TO SLIGHTLY ABV NORMAL
TEMPS.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
VFR WILL PREVAIL FOR THE REMAINDER OF THE AFTN AND INTO THE EVNG
HRS WITH FEW-SCT DIURNAL CU AND SCT-BKN CI. LATER TNGT...PROFILES
FROM THE NAM/GFS SUGGEST ADVECTION/DVLPMNT OF LOWER-LVL STRATUS
INTO PORTIONS OF NE PA AND THE SRN TIER OF NY. RUC AND LCL WRF
PROFILES ARE NOT AS ADAMANT ON THIS DVLPMNT. ATTM SAT PIX SHOW LTL
IN THE WAY OF LOWER CLDS TO OUR S AND SE...SO HEDGED HERE
INDICATING POTNL FOR SCT 1.5-2.5 KFT AT AVP/BGM AFTER 09Z. AT
ELM...A TUFF CALL BUT THINK ANY RESTRICTIONS THERE WOULD BE
RELATED TO VLY FOG/STRATUS FORMATION. VFR TO PREVAIL TMRW AFTER
ANY EARLY MRNG STRICTIONS. WINDS TNGT SELY 5 KTS OR LESS...BECMG
SRLY 10-15 KTS ON SAT.
OUTLOOK...
SATURDAY...PRIMARILY VFR.
SAT NIGHT...PATCHY MVFR LATE IN HZ/BR.
SUN THROUGH TUESDAY...RESTRICTIONS FROM SCT SHRA/TSRA...MAINLY SUNDAY
AND TUESDAY.
WED...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJP
NEAR TERM...DJP/RRM
SHORT TERM...DJP
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1001 AM EDT FRI AUG 29 2014
.SYNOPSIS...
SURFACE HIGH PRESSURE TRANSLATING EASTWARD ACROSS NEW YORK AND NEW
ENGLAND WILL BRING PLEASANT AND DRY WEATHER CONDITIONS TO THE NORTH
COUNTRY TODAY AND TONIGHT. WARMER AND MORE HUMID WEATHER WILL RETURN
FOR THE WEEKEND AS HIGH PRESSURE SHIFTS EAST OF THE REGION AND SOUTH
TO SOUTHWEST FLOW DEVELOPS. SATURDAY SHOULD BE PRECIPITATION FREE...
BUT SHOWERS AND THUNDERSTORMS ARE LIKELY SUNDAY AFTERNOON AS AN
UPPER LEVEL DISTURBANCE MOVES INTO THE REGION FROM THE GREAT LAKES.
SOME THUNDERSTORMS ON SUNDAY ARE EXPECTED TO PRODUCE BRIEF HEAVY
DOWNPOURS. ABOVE NORMAL TEMPERATURES...WITH VALLEY HIGHS
GENERALLY IN THE 80S...WILL CONTINUE THROUGH MOST OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 11 PM THIS EVENING/...
AS OF 954 AM EDT FRIDAY...HIGH PRESSURE WILL CONTINUE TO CREST
OVER THE REGION TODAY BRINGING A MOSTLY SUNNY DAY TO MUCH OF THE
AREA. STILL HAVE A LOW STRATUS DECK TRAPPED UNDER THE SUBSIDENCE
INVERSION AND NORTHERLY FLOW IN THE CHAMPLAIN VALLEY AND ALONG THE
WESTERN SLOPES OF THE GREEN MOUNTAINS. THIS HAS BEEN BEGINNING TO
SHRINK OVER THE PAST 1-2 HOURS. ALSO STARTING TO SEE OTHER AREAS MIX
OUT AS INDICATED BY DAYTIME CUMULUS FORMING IN PARTS OF EASTERN
VERMONT. THUS EXPECTING THE CHAMPLAIN VALLEY STRATUS TO CLEAR OUT
AROUND 16Z (NOON). LATEST RAP/HRRR/4KM NAM SUPPORT THIS TIMING AS
WELL. TEMPERATURES WARMING UP NICELY IN AREAS THAT ARE SEEING
SUN...SO HIGHS FROM 70 TO 75 STILL LOOK GOOD.
PREVIOUS DISCUSSION FROM 740 AM FRIDAY...
MODERATELY STRONG SURFACE ANTICYCLONE AND ASSOCIATED MID-
TROPOSPHERIC RIDGE WILL BUILD EWD INTO THE NORTH COUNTRY TODAY.
LINGERING STRATOCUMULUS ACROSS NRN VT AND IN THE CHAMPLAIN VALLEY
WILL DISSIPATE THRU 15-16Z (PER RAP LOW-LEVEL RH TRENDS) OWING TO
INCREASED SUBSIDENCE AND PBL MIXING...AND PATCHY EARLY AM FOG WILL
QUICKLY DISSIPATE AFTER 12Z WITH NEAR FULL SUNSHINE EXPECTED
TODAY. WINDS WILL BE LIGHT AND VARIABLE IN VICINITY OF HIGH
PRESSURE...AND DEWPOINTS WILL REMAIN LOW - GENERALLY IN THE UPPER
40S TO LOWER 50S. LEANED TOWARD WARMER NAM- MOS GUIDANCE...WITH
VALLEY HIGHS IN THE 72-76F RANGE. ALL IN ALL A VERY PLEASANT DAY
FOR OUTDOOR ACTIVITIES UNDER RESPLENDENT BLUE SKIES.
SURFACE HIGH PRESSURE REMAINS IN CONTROL TONIGHT WILL DRIFTING
EWD TOWARD THE GULF OF MAINE AFTER MIDNIGHT. AS A RESULT...SHOULD
SEE SOME SOUTHERLY RETURN FLOW DEVELOP LATE...ESPECIALLY IN THE
CHAMPLAIN VALLEY WITH CHANNELING EFFECTS. WINDS GENERALLY AROUND
10 MPH IN THE CHAMPLAIN VALLEY...BUT WITH STEEP LAPSE RATES OVER
LAKE CHAMPLAIN DUE TO WARM LAKE WATERS...WILL SEE THE DEVELOPMENT
OF 15-25 KT SOUTH WINDS BY 09Z OVER THE OPEN WATERS OF LAKE
CHAMPLAIN. MODELS SUGGEST INCREASING RH IN 300-500MB LAYER...SO
WILL LIKELY SEE AN INCREASE IN CIRRUS FROM WEST TO EAST OVERNIGHT.
NO PRECIPITATION IS EXPECTED. FOG WILL BE MOST PREVALENT ACROSS
THE VALLEYS OF CENTRAL AND ERN VT WHERE WINDS JUST ABOVE THE PBL
WILL BE LIGHTEST AND CIRRUS CLOUDS WILL ARRIVE A BIT LATER.
OVERNIGHT LOWS WILL GENERALLY BE IN THE LOW-MID 50S...WITH A FEW
UPPER 40S IN THE NRN ADIRONDACKS AND FAR NERN VT.
&&
.SHORT TERM /11 PM THIS EVENING THROUGH SUNDAY/...
AS OF 329 AM EDT FRIDAY...SOUTH TO SOUTHWESTERLY LOW-LEVEL FLOW WILL
BE IN PLACE ACROSS THE NORTH COUNTRY ON SATURDAY...BETWEEN SFC
HIGH PRESSURE DEPARTING TO THE EAST AND A WEAK SFC LOW AND MID-
LEVEL TROUGH ACROSS THE GREAT LAKES. MODERATE LOW-TO-MID LEVEL WAA
IS PROGGED BY 00Z NAM/GFS...WITH 850MB THERMAL RIDGE OF +15 TO
+16C BUILDING INTO THE REGION BY 00Z SUNDAY. ISSUE ON TEMPERATURE
WILL BE CLOUDS...AS HIGH 500-300MB RH SUGGESTS FILTERED SUNSHINE
THROUGH CIRRUS/ALTOSTRATUS LAYER. ADJUSTED A BIT ABOVE MOS
CONSENSUS...WITH HIGHS IN THE 80-83F FOR MOST VALLEY
SECTIONS...BUT NOT QUITE AS WARM AS IT COULD BE UNDER FULL SUN. S-SW
WINDS GENERALLY 10-15 MPH. WITH MID-LEVEL RIDGING STILL IN PLACE
AND NOT MUCH EVIDENCE FOR LOW- LEVEL CONVERGENCE...IT APPEARS
SATURDAY WILL REMAIN DRY AREAWIDE...AND WILL KEEP POPS BELOW 15
PERCENT. DEWPOINTS WILL SLOWLY CLIMB...LIKELY REACHING THE UPR
50S.
WEAK MID-LEVEL HEIGHT FALLS COMMENCE SATURDAY NIGHT AS MID-LEVEL
SHORTWAVE TROUGH PROGRESSES EWD ACROSS THE GREAT LAKES. SHOULD SEE
MOSTLY CLOUDY SKIES...WITH A CHANCE FOR A FEW SHOWERS DEVELOPING
ACROSS NRN NY...AND PERHAPS FAR NRN VT TOWARD DAYBREAK SUNDAY.
CLOUDS AND CONTINUED LIGHT SOUTH WINDS SAT NIGHT...COMBINED WITH
WARMER AIR MASS WILL RESULT IN VERY MILD OVERNIGHT LOWS...RANGING
FROM THE UPR 50S ACROSS THE CT RIVER VALLEY...TO 65-68F IN THE
CHAMPLAIN AND ST. LAWRENCE VALLEYS.
SUNDAY LOOKS LIKE THE BEST CHANCE FOR PRECIPITATION OVER THE NEXT
SEVERAL DAYS. SHORTWAVE TROUGH PROVIDES MID-LEVEL UVV WHILE WEAK
SURFACE-BASED INSTABILITY DEVELOPS WITH DAYTIME HEATING (SBCAPE
VALUES OF 500-1000 J/KG). DEEP LAYER SHEAR IS NOT PARTICULARLY
IMPRESSIVE...WITH SFC-6KM BULK SHEAR OF ONLY 20-25 KTS. COMBINED
WITH ONLY WEAK INSTABILITY WITH ABUNDANT CLOUD COVER IN PLACE...NOT
ANTICIPATING ANY SEVERE WEATHER ACTIVITY. THAT SAID...SHOWER AND
THUNDERSTORM ACTIVITY WILL GRADUALLY BECOME MORE WIDESPREAD TOWARD
AFTERNOON WITH PEAK HEATING. WHILE NOT A "WASHOUT"...THESE SHOWERS
COULD BE LOCALLY HEAVY...AS PW VALUES APPROACH 2.00" IN BOTH THE NAM
AND GFS. HAVE INCLUDED HEAVY DOWNPOUR MENTION IN THE HAZARDOUS
WEATHER OUTLOOK AND IN THE FORECAST GRIDS. DEFINITELY WOULD BE
GOOD TO HAVE AN INDOOR BACKUP PLAN FOR ANY PLANNED OUTINGS ON
SUNDAY GIVING POTENTIAL FOR BRIEF HEAVY RAINFALL. HIGH TEMPERATURES
WILL RANGE FROM THE UPR 70S TO LOWER 80S.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 329 AM EDT FRIDAY...FAIRLY ACTIVE WEATHER EXPECTED FOR THE FIRST
PART OF THE EXTENDED FORECAST PERIOD...SUNDAY NIGHT THROUGH
TUESDAY NIGHT...WITH DRYING TAKING PLACE WEDNESDAY AND THURSDAY.
COLD FRONT MOVES ACROSS THE AREA SUNDAY NIGHT AND THUS GOING
FORECAST OF LIKELY SHOWERS AND THUNDERSTORMS LOOKS REAL GOOD. NOT
MUCH AIR MASS CHANGE BEHIND THE FRONT ON MONDAY AND THUS
SUFFICIENT INSTABILITY SHOULD DEVELOP MONDAY AFTERNOON FOR SOME
SHOWERS AND STORMS TO DEVELOP. A BRIEF BREAK IN THE CONVECTION
TAKES PLACE LATER MONDAY NIGHT AND TUESDAY MORNING BEFORE ANOTHER
COLD FRONT MOVES INTO THE REGION TUESDAY AFTERNOON. THUS LOOKING
AT ANOTHER CHANCE OF SHOWERS AND THUNDERSTORMS THROUGH TUESDAY
EVENING BEFORE DRIER WESTERLY FLOW ALOFT DEVELOPS OVER THE AREA
WEDNESDAY AND THURSDAY. THERMAL PROFILE THROUGHOUT THE EXTENDED
SUGGESTS DAYTIME HIGHS WILL BE AT OR A FEW DEGREES ABOVE SEASONAL
NORMALS.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
THROUGH 12Z SATURDAY...VFR-MVFR CEILINGS WILL EXIST THROUGH ABOUT
16Z BEFORE ALL SITES BECOME VFR WITH VERY LITTLE IN THE WAY OF ANY
CLOUDS FOR THE REMAINDER OF THE PERIOD. IFR-LIFR VISIBILITIES WILL
EXIST AT KSLK THROUGH 14Z BEFORE BECOMING VFR LIKE ALL OTHER SITES
FOR THE REMAINDER OF THE PERIOD. WINDS WILL GENERALLY BE LIGHT AND
VARIABLE THROUGH THE PERIOD.
OUTLOOK 12Z SATURDAY THROUGH TUESDAY...
12Z SAT ONWARD...MAINLY VFR...WITH MVFR/BRIEF IFR IN SCATTERED
SHOWERS AND THUNDERSTORMS.
&&
.MARINE...
SOUTH WINDS WILL INCREASE SHARPLY ON LAKE CHAMPLAIN TOWARD
DAYBREAK SATURDAY...AS THE PRESSURE GRADIENT INCREASES BETWEEN
HIGH PRESSURE DEPARTING EAST OF NEW ENGLAND...AND A DEVELOPING LOW
PRESSURE SYSTEM ACROSS THE CENTRAL GREAT LAKES. LOOKING AT WINDS
15-20 KNOTS WITH GUSTS TO 25 KNOTS AFTER 5 AM...WITH SUSTAINED
SOUTH WINDS 15-25 KNOTS THROUGH MUCH OF THE DAYLIGHT HOURS ON
SATURDAY. WAVES OVER THE BROAD PORTION OF LAKE CHAMPLAIN WILL
BUILD TO 2 TO 3 FEET SATURDAY MORNING.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...BANACOS
NEAR TERM...BANACOS/MUCCILLI
SHORT TERM...BANACOS
LONG TERM...EVENSON
AVIATION...EVENSON/KGM
MARINE...TEAM BTV
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
748 AM EDT FRI AUG 29 2014
.SYNOPSIS...
SURFACE HIGH PRESSURE TRANSLATING EASTWARD ACROSS NEW YORK AND NEW
ENGLAND WILL BRING PLEASANT AND DRY WEATHER CONDITIONS TO THE NORTH
COUNTRY TODAY AND TONIGHT. WARMER AND MORE HUMID WEATHER WILL RETURN
FOR THE WEEKEND AS HIGH PRESSURE SHIFTS EAST OF THE REGION AND SOUTH
TO SOUTHWEST FLOW DEVELOPS. SATURDAY SHOULD BE PRECIPITATION FREE...
BUT SHOWERS AND THUNDERSTORMS ARE LIKELY SUNDAY AFTERNOON AS AN
UPPER LEVEL DISTURBANCE MOVES INTO THE REGION FROM THE GREAT LAKES.
SOME THUNDERSTORMS ON SUNDAY ARE EXPECTED TO PRODUCE BRIEF HEAVY
DOWNPOURS. ABOVE NORMAL TEMPERATURES...WITH VALLEY HIGHS
GENERALLY IN THE 80S...WILL CONTINUE THROUGH MOST OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 740 AM EDT FRIDAY...MODERATELY STRONG SURFACE ANTICYCLONE
AND ASSOCIATED MID-TROPOSPHERIC RIDGE WILL BUILD EWD INTO THE
NORTH COUNTRY TODAY. LINGERING STRATOCUMULUS ACROSS NRN VT AND IN
THE CHAMPLAIN VALLEY WILL DISSIPATE THRU 15-16Z (PER RAP LOW-LEVEL RH
TRENDS) OWING TO INCREASED SUBSIDENCE AND PBL MIXING...AND PATCHY
EARLY AM FOG WILL QUICKLY DISSIPATE AFTER 12Z WITH NEAR FULL
SUNSHINE EXPECTED TODAY. WINDS WILL BE LIGHT AND VARIABLE IN
VICINITY OF HIGH PRESSURE...AND DEWPOINTS WILL REMAIN LOW -
GENERALLY IN THE UPPER 40S TO LOWER 50S. LEANED TOWARD WARMER NAM-
MOS GUIDANCE...WITH VALLEY HIGHS IN THE 72-76F RANGE. ALL IN ALL A
VERY PLEASANT DAY FOR OUTDOOR ACTIVITIES UNDER RESPLENDENT BLUE
SKIES.
SURFACE HIGH PRESSURE REMAINS IN CONTROL TONIGHT WILL DRIFTING
EWD TOWARD THE GULF OF MAINE AFTER MIDNIGHT. AS A RESULT...SHOULD
SEE SOME SOUTHERLY RETURN FLOW DEVELOP LATE...ESPECIALLY IN THE
CHAMPLAIN VALLEY WITH CHANNELING EFFECTS. WINDS GENERALLY AROUND
10 MPH IN THE CHAMPLAIN VALLEY...BUT WITH STEEP LAPSE RATES OVER
LAKE CHAMPLAIN DUE TO WARM LAKE WATERS...WILL SEE THE DEVELOPMENT
OF 15-25 KT SOUTH WINDS BY 09Z OVER THE OPEN WATERS OF LAKE
CHAMPLAIN. MODELS SUGGEST INCREASING RH IN 300-500MB LAYER...SO
WILL LIKELY SEE AN INCREASE IN CIRRUS FROM WEST TO EAST OVERNIGHT.
NO PRECIPITATION IS EXPECTED. FOG WILL BE MOST PREVALENT ACROSS
THE VALLEYS OF CENTRAL AND ERN VT WHERE WINDS JUST ABOVE THE PBL
WILL BE LIGHTEST AND CIRRUS CLOUDS WILL ARRIVE A BIT LATER.
OVERNIGHT LOWS WILL GENERALLY BE IN THE LOW-MID 50S...WITH A FEW
UPPER 40S IN THE NRN ADIRONDACKS AND FAR NERN VT.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
AS OF 329 AM EDT FRIDAY...SOUTH TO SOUTHWESTERLY LOW-LEVEL FLOW WILL
BE IN PLACE ACROSS THE NORTH COUNTRY ON SATURDAY...BETWEEN SFC
HIGH PRESSURE DEPARTING TO THE EAST AND A WEAK SFC LOW AND MID-
LEVEL TROUGH ACROSS THE GREAT LAKES. MODERATE LOW-TO-MID LEVEL WAA
IS PROGGED BY 00Z NAM/GFS...WITH 850MB THERMAL RIDGE OF +15 TO
+16C BUILDING INTO THE REGION BY 00Z SUNDAY. ISSUE ON TEMPERATURE
WILL BE CLOUDS...AS HIGH 500-300MB RH SUGGESTS FILTERED SUNSHINE
THROUGH CIRRUS/ALTOSTRATUS LAYER. ADJUSTED A BIT ABOVE MOS
CONSENSUS...WITH HIGHS IN THE 80-83F FOR MOST VALLEY
SECTIONS...BUT NOT QUITE AS WARM AS IT COULD BE UNDER FULL SUN. S-SW
WINDS GENERALLY 10-15 MPH. WITH MID-LEVEL RIDGING STILL IN PLACE
AND NOT MUCH EVIDENCE FOR LOW- LEVEL CONVERGENCE...IT APPEARS
SATURDAY WILL REMAIN DRY AREAWIDE...AND WILL KEEP POPS BELOW 15
PERCENT. DEWPOINTS WILL SLOWLY CLIMB...LIKELY REACHING THE UPR
50S.
WEAK MID-LEVEL HEIGHT FALLS COMMENCE SATURDAY NIGHT AS MID-LEVEL
SHORTWAVE TROUGH PROGRESSES EWD ACROSS THE GREAT LAKES. SHOULD SEE
MOSTLY CLOUDY SKIES...WITH A CHANCE FOR A FEW SHOWERS DEVELOPING
ACROSS NRN NY...AND PERHAPS FAR NRN VT TOWARD DAYBREAK SUNDAY.
CLOUDS AND CONTINUED LIGHT SOUTH WINDS SAT NIGHT...COMBINED WITH
WARMER AIR MASS WILL RESULT IN VERY MILD OVERNIGHT LOWS...RANGING
FROM THE UPR 50S ACROSS THE CT RIVER VALLEY...TO 65-68F IN THE
CHAMPLAIN AND ST. LAWRENCE VALLEYS.
SUNDAY LOOKS LIKE THE BEST CHANCE FOR PRECIPITATION OVER THE NEXT
SEVERAL DAYS. SHORTWAVE TROUGH PROVIDES MID-LEVEL UVV WHILE WEAK
SURFACE-BASED INSTABILITY DEVELOPS WITH DAYTIME HEATING (SBCAPE
VALUES OF 500-1000 J/KG). DEEP LAYER SHEAR IS NOT PARTICULARLY
IMPRESSIVE...WITH SFC-6KM BULK SHEAR OF ONLY 20-25 KTS. COMBINED
WITH ONLY WEAK INSTABILITY WITH ABUNDANT CLOUD COVER IN PLACE...NOT
ANTICIPATING ANY SEVERE WEATHER ACTIVITY. THAT SAID...SHOWER AND
THUNDERSTORM ACTIVITY WILL GRADUALLY BECOME MORE WIDESPREAD TOWARD
AFTERNOON WITH PEAK HEATING. WHILE NOT A "WASHOUT"...THESE SHOWERS
COULD BE LOCALLY HEAVY...AS PW VALUES APPROACH 2.00" IN BOTH THE NAM
AND GFS. HAVE INCLUDED HEAVY DOWNPOUR MENTION IN THE HAZARDOUS
WEATHER OUTLOOK AND IN THE FORECAST GRIDS. DEFINITELY WOULD BE
GOOD TO HAVE AN INDOOR BACKUP PLAN FOR ANY PLANNED OUTINGS ON
SUNDAY GIVING POTENTIAL FOR BRIEF HEAVY RAINFALL. HIGH TEMPERATURES
WILL RANGE FROM THE UPR 70S TO LOWER 80S.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 329 AM EDT FRIDAY...FAIRLY ACTIVE WEATHER EXPECTED FOR THE FIRST
PART OF THE EXTENDED FORECAST PERIOD...SUNDAY NIGHT THROUGH
TUESDAY NIGHT...WITH DRYING TAKING PLACE WEDNESDAY AND THURSDAY.
COLD FRONT MOVES ACROSS THE AREA SUNDAY NIGHT AND THUS GOING
FORECAST OF LIKELY SHOWERS AND THUNDERSTORMS LOOKS REAL GOOD. NOT
MUCH AIR MASS CHANGE BEHIND THE FRONT ON MONDAY AND THUS
SUFFICIENT INSTABILITY SHOULD DEVELOP MONDAY AFTERNOON FOR SOME
SHOWERS AND STORMS TO DEVELOP. A BRIEF BREAK IN THE CONVECTION
TAKES PLACE LATER MONDAY NIGHT AND TUESDAY MORNING BEFORE ANOTHER
COLD FRONT MOVES INTO THE REGION TUESDAY AFTERNOON. THUS LOOKING
AT ANOTHER CHANCE OF SHOWERS AND THUNDERSTORMS THROUGH TUESDAY
EVENING BEFORE DRIER WESTERLY FLOW ALOFT DEVELOPS OVER THE AREA
WEDNESDAY AND THURSDAY. THERMAL PROFILE THROUGHOUT THE EXTENDED
SUGGESTS DAYTIME HIGHS WILL BE AT OR A FEW DEGREES ABOVE SEASONAL
NORMALS.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
THROUGH 12Z SATURDAY...VFR-MVFR CEILINGS WILL EXIST THROUGH ABOUT
16Z BEFORE ALL SITES BECOME VFR WITH VERY LITTLE IN THE WAY OF ANY
CLOUDS FOR THE REMAINDER OF THE PERIOD. IFR-LIFR VISIBILITIES WILL
EXIST AT KSLK THROUGH 14Z BEFORE BECOMING VFR LIKE ALL OTHER SITES
FOR THE REMAINDER OF THE PERIOD. WINDS WILL GENERALLY BE LIGHT AND
VARIABLE THROUGH THE PERIOD.
OUTLOOK 12Z SATURDAY THROUGH TUESDAY...
12Z SAT ONWARD...MAINLY VFR...WITH MVFR/BRIEF IFR IN SCATTERED
SHOWERS AND THUNDERSTORMS.
&&
.MARINE...
SOUTH WINDS WILL INCREASE SHARPLY ON LAKE CHAMPLAIN TOWARD
DAYBREAK SATURDAY...AS THE PRESSURE GRADIENT INCREASES BETWEEN
HIGH PRESSURE DEPARTING EAST OF NEW ENGLAND...AND A DEVELOPING LOW
PRESSURE SYSTEM ACROSS THE CENTRAL GREAT LAKES. LOOKING AT WINDS
15-20 KNOTS WITH GUSTS TO 25 KNOTS AFTER 5 AM...WITH SUSTAINED
SOUTH WINDS 15-25 KNOTS THROUGH MUCH OF THE DAYLIGHT HOURS ON
SATURDAY. WAVES OVER THE BROAD PORTION OF LAKE CHAMPLAIN WILL
BUILD TO 2 TO 3 FEET SATURDAY MORNING.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...BANACOS
NEAR TERM...BANACOS
SHORT TERM...BANACOS
LONG TERM...EVENSON
AVIATION...EVENSON/KGM
MARINE...TEAM BTV
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1047 PM EDT SAT AUG 30 2014
.SYNOPSIS...DEEP HIGH PRESSURE WILL EXTEND OVER THE REGION THROUGH
THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1045 PM SATURDAY...
THE LATEST SURFACE ANALYSIS CONTINUED TO SHOW A SLACK GRADIENT OVER
CENTRAL NORTH CAROLINA. RADAR SHOWED EARLIER SHOWERS HAD
DIMINISHED...AS THE SEA BREEZE HAD MOVED NORTH AND WEAKENED WHILE
VERY DRY MID-LEVEL AIR MOVED EAST ACROSS CENTRAL AND EASTERN NORTH
CAROLINA ON WATER VAPOR IMAGERY. K INDICES SHOULD FALL INTO THE
TEENS AS BUFR SOUNDINGS FROM THE GFS AND NAM ALONG WITH RAP
SOUNDINGS SHOW AN OVERALL STABLE AIR MASS THEN.
SOME OF THE TEMPERATURES ACROSS CENTRAL NORTH CAROLINA FELL QUICKLY
DURING MID-EVENING...BUT WITH SOME THIN CIRRUS MOVING EAST FROM DEEP
CONVECTION WELL UPSTREAM...ALONG WITH SURFACE DEW POINTS AROUND 70
TO THE LOWER 70S IN MOST LOCATIONS...TEMPERATURES ARE NOT EXPECTED
TO CONTINUE THAT RAPID FALL. LOWS SHOULD MOSTLY BE WITHIN A DEGREE
OR TWO OF 70. SOME LOW CLOUDS REMAIN POSSIBLE LATE TONIGHT
PARTICULARLY AS NOTED ON NAM BUFR SOUNDINGS AND THE SREF
PROBABILISTIC GUIDANCE...AND ALLUDED TO MORE ON THE GFS 18Z MOS
GUIDANCE OUTPUT FROM ITS EARLIER...MORE OPTIMISTIC 12Z GUIDANCE. THE
LATEST HRRR WRF WOULD SUGGEST A BETTER POTENTIAL FOR LOW CLOUDS LATE
TONIGHT IN A NARROW AXIS ALONG AND WEST OF U.S. 1...WHERE SREF
PROBABILITIES ARE A LITTLE HIGHER RELATIVE TO THE REST OF THE AREA
AND CLOSER TO THE HIGHER 925MB WINDS. THOSE 925MB WINDS SEEM A
LITTLE HIGH FOR FOG IN MOST PLACES...TO 20KT TOWARD THE TRIAD LATE
TONIGHT...BUT THE LOWER VALUES OF 10 TO 15KT TOWARD INTERSTATE 95
ALONG WITH EXPECTED DEW POINTS IN THE LOWER 70S COULD ALLOW A LITTLE
MORE NOTICEABLE FOG IN PATCHES TOWARD THERE LATE.
&&
.SHORT TERM /SUNDAY AND SUNDAY NIGHT/...
AS OF 230 PM SATURDAY...
A SHORT WAVE TROUGH OVER THE MS RIVER VALLEY TO START THE DAY WILL
LIFT TO THE NORTHEAST INTO THE OH VALLEY THROUGH SUNDAY NIGHT.
HOWEVER...ITS ASSOCIATED ENERGY AND DEEP MOISTURE PLUME (EMANATING
FROM THE GULF) WILL LARGELY REMAIN WEST AND NORTH OF CENTRAL NC. IN
ADDITION...THE SUBTROPICAL RIDGE CENTERED OVER THE SOUTHEAST COAST
SHOULD ALSO HELP KEEP THE BETTER RAIN CHANCES WEST OF THE AREA.
THEREFORE...WILL CONTINUE THE FORECAST THINKING OF ONLY ISOLATED TO
WIDELY SCATTERED SHOWERS/STORMS...WITH THE BEST CHANCES ACROSS THE
WEST DUE TO THE PROXIMITY OF THE ABOVE FEATURES. TEMPS WILL CONTINUE
TO BE ABOVE NORMAL...WITH HIGHS GENERALLY IN THE LOWER 90S AND
OVERNIGHT LOWS AROUND 70 DEGREES.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
AS OF 200 PM SATURDAY...
WITH ROUGHLY 3 WEEKS OF SUMMER REMAINING (AUTUMN EQUINOX IS SEPT
23)...THE WESTWARD EXPANSION OF THE SUBTROPICAL RIDGE ACROSS MUCH OF
THE SOUTHERN CONUS...WITH THE MAIN BELT OF WESTERLIES RETREATING
NORTHWARD ALONG THE US-CANADA BORDER WILL RESULT IN THE FIRST
PROLONGED PERIOD OF SUMMERTIME HEAT AND CONVECTIVE RAIN CHANCES THAT
CENTRAL NC HAS SEEN THIS SEASON. AFTERNOON THICKNESSES ARE PROGGED
TO RUN 25 TO 30 METERS ABOVE CLIMATOLOGY...WHICH SHOULD SUPPORT
DAYTIME HIGHS RANGING FROM 90 TO 95F WITH LOWS IN THE UPPER 68 TO
74F.
A LOW AMPLITUDE TROUGH MOVING EASTWARD ACROSS THE NORTHEAST AND MID-
ATLANTIC STATES WILL TEMPORARILY FLATTEN THE UPPER ANTICYCLONE LONG
ENOUGH TO ALLOW A WEAK SURFACE FRONT TO APPROACH NC FROM THE
NORTH...BUT RECENT MODEL TRENDS OVER THE LAST COUPLE OF DAYS REALLY
WASHES OUT THE FRONT TO OUR NORTH DURING THE LATE WEDNESDAY/THURSDAY
PERIOD. AS SUCH...GRIDDED DATABASE WILL CONTINUE TO EXHIBIT
DIURNALLY DRIVEN CONVECTION ISOLATED TO WIDELY SCATTERED STORMS EACH
AFTERNOON...FIRING WITHIN A MODERATELY UNSTABLE AIRMASS ALONG A LEE
SIDE SURFACE TROUGH.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
AS OF 751 PM SATURDAY...
VFR CONDITIONS WILL CONTINUE THROUGH THE EVENING. LOW LEVEL MOISTURE
REMAINS HIGH ACROSS THE AREA WITH LIGHT SURFACE WINDS... AND IFR
CONDITIONS WITH STRATUS... AND POSSIBLY SOME PATCHY FOG.... ARE
EXPECTED TO DEVELOP IN THE EARLY MORNING HOURS SUNDAY AT
KRDU...KRWI...AND KFAY... WHERE DEWPOINTS ARE HIGHEST. MVFR
CONDITIONS ARE POSSIBLE AT KGSO AND KINT. CONDITIONS WILL RETURN TO
VFR AFTER 12Z SUNDAY... WITH A FEW SHOWERS/THUNDERSTORMS POSSIBLE IN
THE AFTERNOON.
OUTLOOK...A SUMMERTIME PATTERN WILL PERSIST THROUGH EARLY/MID NEXT
WEEK...WITH ISOLATED TO SCATTERED AFTERNOON/EVENING CONVECTION AND A
POTENTIAL FOR EARLY MORNING FOG/STRATUS.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...GIH
NEAR TERM...DJF
SHORT TERM...KRD
LONG TERM...CBL
AVIATION...SEC/KRD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
752 PM EDT SAT AUG 30 2014
.SYNOPSIS...DEEP HIGH PRESSURE WILL EXTEND OVER THE REGION THROUGH
THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 740 PM SATURDAY...
THE LATEST SURFACE ANALYSIS SHOWED A SLACK GRADIENT OVER CENTRAL
NORTH CAROLINA. RADAR IMAGERY SHOWED THE SEA BREEZE HAD MOVED WELL
INLAND...MOVING NORTH THROUGH THE TRIANGLE AND HEADED TOWARD
INTERSTATE 40/85. THE SPC MESOANALYSIS SHOWED MLCAPE AROUND
1500J/KG...THOUGH DESPITE THE INSTABILITY SHEAR WAS VERY WEAK AND
THERE WAS JUST ENOUGH LIFT TO PRODUCE ISOLATED SHOWERS. TOTAL LIFT
AND CONVECTIVE DEVELOPMENT COULD ALSO BE FURTHER INHIBITED BY AN
AXIS OF VERY DRY MID-LEVEL AIR NOTED ON WATER VAPOR OVER CENTRAL
NORTH CAROLINA. DIURNALLY...THE SHOWERS SHOULD DIMINISH THIS EVENING
ESPECIALLY AS AN AXIS OF LOWER PRECIPITABLE WATER VALUES...NEAR
NORMAL AT ABOUT 1.3 INCHES...IS FORECAST BY THE RAP TO MOVE EAST
FROM THE FOOTHILLS AND FAR WESTERN PIEDMONT OVERNIGHT...WITH K
INDICES FALLING INTO THE TEENS AS BUFR SOUNDINGS FROM THE GFS AND
NAM ALONG WITH RAP SOUNDINGS SHOW AN OVERALL STABLE AIR MASS THEN.
OVERNIGHT LOW TEMPERATURES HAVE WARMED ON THE MAV MOS GUIDANCE FROM
12Z TO 18Z...CLOSER TO THE MET MOS GUIDANCE WHICH HAS APPARENTLY
PERFORMED A LITTLE BETTER OVER THE LAST DAY OR TWO. STILL...THE
BASIC FORECAST FOR MINIMUM TEMPERATURES REMAINS THE SAME...MOSTLY
WITHIN A DEGREE OR TWO OF 70. SOME LOW CLOUDS ARE POSSIBLE LATE
TONIGHT PARTICULARLY AS NOTED ON NAM BUFR SOUNDINGS AND THE SREF
PROBABILISTIC GUIDANCE...AND ALLUDED TO MORE ON THE GFS 18Z MOS
GUIDANCE OUTPUT FROM ITS EARLIER...MORE OPTIMISTIC 12Z GUIDANCE.
925MB WINDS SEEM A LITTLE HIGH FOR FOG IN MOST PLACES...TO 20KT
TOWARD THE TRIAD LATE TONIGHT...BUT THE LOWER VALUES OF 10 TO 15KT
TOWARD INTERSTATE 95 ALONG WITH EXPECTED DEW POINTS IN THE LOWER 70S
COULD ALLOW A LITTLE MORE NOTICEABLE FOG IN PATCHES TOWARD THERE
LATE.
&&
.SHORT TERM /SUNDAY AND SUNDAY NIGHT/...
AS OF 230 PM SATURDAY...
A SHORT WAVE TROUGH OVER THE MS RIVER VALLEY TO START THE DAY WILL
LIFT TO THE NORTHEAST INTO THE OH VALLEY THROUGH SUNDAY NIGHT.
HOWEVER...ITS ASSOCIATED ENERGY AND DEEP MOISTURE PLUME (EMANATING
FROM THE GULF) WILL LARGELY REMAIN WEST AND NORTH OF CENTRAL NC. IN
ADDITION...THE SUBTROPICAL RIDGE CENTERED OVER THE SOUTHEAST COAST
SHOULD ALSO HELP KEEP THE BETTER RAIN CHANCES WEST OF THE AREA.
THEREFORE...WILL CONTINUE THE FORECAST THINKING OF ONLY ISOLATED TO
WIDELY SCATTERED SHOWERS/STORMS...WITH THE BEST CHANCES ACROSS THE
WEST DUE TO THE PROXIMITY OF THE ABOVE FEATURES. TEMPS WILL CONTINUE
TO BE ABOVE NORMAL...WITH HIGHS GENERALLY IN THE LOWER 90S AND
OVERNIGHT LOWS AROUND 70 DEGREES.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
AS OF 200 PM SATURDAY...
WITH ROUGHLY 3 WEEKS OF SUMMER REMAINING (AUTUMN EQUINOX IS SEPT
23)...THE WESTWARD EXPANSION OF THE SUBTROPICAL RIDGE ACROSS MUCH OF
THE SOUTHERN CONUS...WITH THE MAIN BELT OF WESTERLIES RETREATING
NORTHWARD ALONG THE US-CANADA BORDER WILL RESULT IN THE FIRST
PROLONGED PERIOD OF SUMMERTIME HEAT AND CONVECTIVE RAIN CHANCES THAT
CENTRAL NC HAS SEEN THIS SEASON. AFTERNOON THICKNESSES ARE PROGGED
TO RUN 25 TO 30 METERS ABOVE CLIMATOLOGY...WHICH SHOULD SUPPORT
DAYTIME HIGHS RANGING FROM 90 TO 95F WITH LOWS IN THE UPPER 68 TO
74F.
A LOW AMPLITUDE TROUGH MOVING EASTWARD ACROSS THE NORTHEAST AND MID-
ATLANTIC STATES WILL TEMPORARILY FLATTEN THE UPPER ANTICYCLONE LONG
ENOUGH TO ALLOW A WEAK SURFACE FRONT TO APPROACH NC FROM THE
NORTH...BUT RECENT MODEL TRENDS OVER THE LAST COUPLE OF DAYS REALLY
WASHES OUT THE FRONT TO OUR NORTH DURING THE LATE WEDNESDAY/THURSDAY
PERIOD. AS SUCH...GRIDDED DATABASE WILL CONTINUE TO EXHIBIT
DIURNALLY DRIVEN CONVECTION ISOLATED TO WIDELY SCATTERED STORMS EACH
AFTERNOON...FIRING WITHIN A MODERATELY UNSTABLE AIRMASS ALONG A LEE
SIDE SURFACE TROUGH.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
AS OF 751 PM SATURDAY...
VFR CONDITIONS WILL CONTINUE THROUGH THE EVENING. LOW LEVEL MOISTURE
REMAINS HIGH ACROSS THE AREA WITH LIGHT SURFACE WINDS... AND IFR
CONDITIONS WITH STRATUS... AND POSSIBLY SOME PATCHY FOG.... ARE
EXPECTED TO DEVELOP IN THE EARLY MORNING HOURS SUNDAY AT
KRDU...KRWI...AND KFAY... WHERE DEWPOINTS ARE HIGHEST. MVFR
CONDITIONS ARE POSSIBLE AT KGSO AND KINT. CONDITIONS WILL RETURN TO
VFR AFTER 12Z SUNDAY... WITH A FEW SHOWERS/THUNDERSTORMS POSSIBLE IN
THE AFTERNOON.
OUTLOOK...A SUMMERTIME PATTERN WILL PERSIST THROUGH EARLY/MID NEXT
WEEK...WITH ISOLATED TO SCATTERED AFTERNOON/EVENING CONVECTION AND A
POTENTIAL FOR EARLY MORNING FOG/STRATUS.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...GIH
NEAR TERM...DJF
SHORT TERM...KRD
LONG TERM...CBL
AVIATION...SEC/KRD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
741 PM EDT SAT AUG 30 2014
.SYNOPSIS...DEEP HIGH PRESSURE WILL EXTEND OVER THE REGION THROUGH
THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 740 PM SATURDAY...
THE LATEST SURFACE ANALYSIS SHOWED A SLACK GRADIENT OVER CENTRAL
NORTH CAROLINA. RADAR IMAGERY SHOWED THE SEA BREEZE HAD MOVED WELL
INLAND...MOVING NORTH THROUGH THE TRIANGLE AND HEADED TOWARD
INTERSTATE 40/85. THE SPC MESOANALYSIS SHOWED MLCAPE AROUND
1500J/KG...THOUGH DESPITE THE INSTABILITY SHEAR WAS VERY WEAK AND
THERE WAS JUST ENOUGH LIFT TO PRODUCE ISOLATED SHOWERS. TOTAL LIFT
AND CONVECTIVE DEVELOPMENT COULD ALSO BE FURTHER INHIBITED BY AN
AXIS OF VERY DRY MID-LEVEL AIR NOTED ON WATER VAPOR OVER CENTRAL
NORTH CAROLINA. DIURNALLY...THE SHOWERS SHOULD DIMINISH THIS EVENING
ESPECIALLY AS AN AXIS OF LOWER PRECIPITABLE WATER VALUES...NEAR
NORMAL AT ABOUT 1.3 INCHES...IS FORECAST BY THE RAP TO MOVE EAST
FROM THE FOOTHILLS AND FAR WESTERN PIEDMONT OVERNIGHT...WITH K
INDICES FALLING INTO THE TEENS AS BUFR SOUNDINGS FROM THE GFS AND
NAM ALONG WITH RAP SOUNDINGS SHOW AN OVERALL STABLE AIR MASS THEN.
OVERNIGHT LOW TEMPERATURES HAVE WARMED ON THE MAV MOS GUIDANCE FROM
12Z TO 18Z...CLOSER TO THE MET MOS GUIDANCE WHICH HAS APPARENTLY
PERFORMED A LITTLE BETTER OVER THE LAST DAY OR TWO. STILL...THE
BASIC FORECAST FOR MINIMUM TEMPERATURES REMAINS THE SAME...MOSTLY
WITHIN A DEGREE OR TWO OF 70. SOME LOW CLOUDS ARE POSSIBLE LATE
TONIGHT PARTICULARLY AS NOTED ON NAM BUFR SOUNDINGS AND THE SREF
PROBABILISTIC GUIDANCE...AND ALLUDED TO MORE ON THE GFS 18Z MOS
GUIDANCE OUTPUT FROM ITS EARLIER...MORE OPTIMISTIC 12Z GUIDANCE.
925MB WINDS SEEM A LITTLE HIGH FOR FOG IN MOST PLACES...TO 20KT
TOWARD THE TRIAD LATE TONIGHT...BUT THE LOWER VALUES OF 10 TO 15KT
TOWARD INTERSTATE 95 ALONG WITH EXPECTED DEW POINTS IN THE LOWER 70S
COULD ALLOW A LITTLE MORE NOTICEABLE FOG IN PATCHES TOWARD THERE
LATE.
&&
.SHORT TERM /SUNDAY AND SUNDAY NIGHT/...
AS OF 230 PM SATURDAY...
A SHORT WAVE TROUGH OVER THE MS RIVER VALLEY TO START THE DAY WILL
LIFT TO THE NORTHEAST INTO THE OH VALLEY THROUGH SUNDAY NIGHT.
HOWEVER...ITS ASSOCIATED ENERGY AND DEEP MOISTURE PLUME (EMANATING
FROM THE GULF) WILL LARGELY REMAIN WEST AND NORTH OF CENTRAL NC. IN
ADDITION...THE SUBTROPICAL RIDGE CENTERED OVER THE SOUTHEAST COAST
SHOULD ALSO HELP KEEP THE BETTER RAIN CHANCES WEST OF THE AREA.
THEREFORE...WILL CONTINUE THE FORECAST THINKING OF ONLY ISOLATED TO
WIDELY SCATTERED SHOWERS/STORMS...WITH THE BEST CHANCES ACROSS THE
WEST DUE TO THE PROXIMITY OF THE ABOVE FEATURES. TEMPS WILL CONTINUE
TO BE ABOVE NORMAL...WITH HIGHS GENERALLY IN THE LOWER 90S AND
OVERNIGHT LOWS AROUND 70 DEGREES.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
AS OF 200 PM SATURDAY...
WITH ROUGHLY 3 WEEKS OF SUMMER REMAINING (AUTUMN EQUINOX IS SEPT
23)...THE WESTWARD EXPANSION OF THE SUBTROPICAL RIDGE ACROSS MUCH OF
THE SOUTHERN CONUS...WITH THE MAIN BELT OF WESTERLIES RETREATING
NORTHWARD ALONG THE US-CANADA BORDER WILL RESULT IN THE FIRST
PROLONGED PERIOD OF SUMMERTIME HEAT AND CONVECTIVE RAIN CHANCES THAT
CENTRAL NC HAS SEEN THIS SEASON. AFTERNOON THICKNESSES ARE PROGGED
TO RUN 25 TO 30 METERS ABOVE CLIMATOLOGY...WHICH SHOULD SUPPORT
DAYTIME HIGHS RANGING FROM 90 TO 95F WITH LOWS IN THE UPPER 68 TO
74F.
A LOW AMPLITUDE TROUGH MOVING EASTWARD ACROSS THE NORTHEAST AND MID-
ATLANTIC STATES WILL TEMPORARILY FLATTEN THE UPPER ANTICYCLONE LONG
ENOUGH TO ALLOW A WEAK SURFACE FRONT TO APPROACH NC FROM THE
NORTH...BUT RECENT MODEL TRENDS OVER THE LAST COUPLE OF DAYS REALLY
WASHES OUT THE FRONT TO OUR NORTH DURING THE LATE WEDNESDAY/THURSDAY
PERIOD. AS SUCH...GRIDDED DATABASE WILL CONTINUE TO EXHIBIT
DIURNALLY DRIVEN CONVECTION ISOLATED TO WIDELY SCATTERED STORMS EACH
AFTERNOON...FIRING WITHIN A MODERATELY UNSTABLE AIRMASS ALONG A LEE
SIDE SURFACE TROUGH.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 130 PM SATURDAY...
VFR CONDITIONS HAVE RETURNED TO THE AREA AS THE LOW CLOUDS LIFTED
INTO A 4-5 KFT CLOUD DECK. A FEW ISOLATED SHOWERS/STORMS WILL BE
POSSIBLE THIS AFTERNOON ASSOCIATED WITH THE INLAND MOVING SEA-BREEZE.
THUS THE BEST CHANCES WILL BE ACROSS THE EAST...BUT HAVE NOT
INCLUDED ANY MENTION IN THE TAFS FOR NOW AS THERE IS LOW CONFIDENCE
WITH RESPECT TO EXACT TIMING/LOCATION (ALTHOUGH KFAY MAY HAVE THE
BEST CHANCE). THEN...ONCE AGAIN PATCHY FOG/LOW STRATUS WILL BE
POSSIBLE TONIGHT INTO EARLY SUNDAY MORNING.
OUTLOOK...A SUMMERTIME PATTERN WILL PERSIST THROUGH EARLY/MID NEXT
WEEK...WITH ISOLATED TO SCATTERED AFTERNOON/EVENING CONVECTION AND A
POTENTIAL FOR EARLY MORNING FOG/STRATUS.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...GIH
NEAR TERM...DJF
SHORT TERM...KRD
LONG TERM...CBL
AVIATION...KRD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
147 PM EDT FRI AUG 29 2014
.SYNOPSIS...A SLOW MOVING BACK DOOR COLD FRONT WILL STALL OUT ACROSS
CENTRAL NORTH CAROLINA TODAY. THE FRONT WILL GRADUALLY DISSIPATE
OVER THE WEEKEND AS A LIGHT SOUTHERLY RETURN FLOW DEVELOPS ACROSS
THE REGION.
&&
.NEAR TERM /TODAY AND TONIGHT/...
AS OF 1230 PM FRIDAY...
AS OF 16Z...LATEST OBSERVATIONS/ANALYSIS INDICATES THE SURFACE FRONT
HAS MADE IT THROUGH 2/3RDS THE FORECAST AREA. EXTENSIVE CLOUD COVER
IS NOTED WITHIN THE NORTHEASTERLY FLOW ALONG AND NORTH OF THE
FRONT...WITH MOSTLY CLEAR SKIES ACROSS THE EXTREME SOUTH. THERE
STILL IS A GREAT LEVEL OF DISAGREEMENT AMONG THE MODELS WITH RESPECT
TO THE EVOLUTION OF THIS CLOUD COVER...WITH THE NAM KEEPING THE
NORTHERN HALF OF THE FORECAST AREA MOSTLY CLOUDY ALL DAY AND THE GFS
AND RAP BREAKING OUT THE CLOUDS SOME WITH MORE IN THE WAY OF
EASTERLY/SOUTHEASTERLY FLOW LATER TODAY. HOWEVER...THE CLOUDS ARE
HANGING IN AND TEMPS REMAINED IN THE 70S ACROSS MUCH OF THE NORTHERN
TIER...MORE SIMILAR TO THE NAM. SENT OUT AN UPDATE TO REFLECT ALL OF
THIS...WITH HIGHS NOW EXPECTED TO BE IN THE LOW/MID 80S ACROSS THE
NORTH TO THE LOWER 90S ACROSS THE EXTREME SOUTH. WITH REGARDS TO
PRECIP CHANCES...ISOLATED TO SCATTERED CONVECTION IS STILL EXPECTED
LATER THIS AFTERNOON... ESPECIALLY IN THE VICINITY OF THE
FRONT...HOWEVER RECENT MODELS TRENDS ARE SHOWING VERY LITTLE IN THE
WAY OF COVERAGE. OVERNIGHT LOWS WILL GENERALLY RANGE FROM THE UPPER
60S ACROSS THE NORTH TO THE LOWER 70S FURTHER SOUTH.
&&
.SHORT TERM /SATURDAY AND SATURDAY NIGHT/...
AS OF 220 AM FRIDAY...
CENTRAL NC WILL REMAIN UNDER THE INFLUENCE OF AN UPPER LEVEL RIDGE
SAT/SAT NIGHT AS THE CENTER OF THE RIDGE CURRENTLY OVER THE
SOUTHEAST STATES SHIFTS SLIGHTLY EAST TOWARD THE COAST. THE
LINGERING FRONTAL ZONE OVER PORTIONS OF CENTRAL NC SHOULD WASH OUT
DURING THE DAY AS A LIGHT S/SE RETURN FLOW DEVELOPS ACROSS THE
REGION. FORECAST SOUNDINGS SUGGEST MARGINAL DESTABILIZATION WITH 500-
1500 J/KG OF MLCAPE SAT AFTERNOON. GIVEN A PROTOTYPICAL SUMMERTIME
`RIDGE` PATTERN...EXPECT ABOVE NORMAL TEMPS...IN THE LOWER 90S.
MARGINAL INSTABILITY AND SEASONABLE MOISTURE (PWAT VALUES OF 1.50-
1.75") WOULD SUPPORT ISOLD CONVECTION ON SATURDAY...THOUGH FORCING
FOR ASCENT WILL BE LIMITED TO THE SEABREEZE AND DIFFERENTIAL
HEATING...PRIMARILY ALONG THE HIGHER TERRAIN IN WESTERN NC...AND IT
IS POSSIBLE THAT NO CONVECTION WILL DEVELOP IN CENTRAL NC. WITH THE
ABOVE IN MIND...WILL INDICATE A SLIGHT CHANCE OF CONVECTION DURING
THE AFT AND EARLY EVE HOURS IN THE WESTERN PIEDMONT AND SE COASTAL
PLAIN. EXPECT NEAR NORMAL LOWS SAT NIGHT IN THE UPPER 60S TO LOWER
70S. -VINCENT
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 245 AM FRIDAY...
A RIDGE WILL BUILD OVER THE SOUTHEASTERN STATES EARLY TO MID WEEK.
THIS WILL EXTEND OUR CURRENT MORE SUMMER-LIKE PATTERN ACROSS NC WELL
INTO WEDNESDAY. THE CORE OF THE UPPER RIDGE IS FORECAST TO BE OVER
THE NC/SC COAST SUNDAY. THE APPROACHING UPPER TROUGH FROM THE OHIO
VALLEY WILL BE DEFLECTED TO OUR NORTH AND WEAKEN SUNDAY NIGHT AND
MONDAY. EVEN WITH THE HEAT AND HUMIDITY WITH THE SOUTHERLY RETURN
FLOW... ONLY ISOLATED AFTERNOON THUNDERSTORMS ARE EXPECTED. THE BEST
CHANCE IS FORECAST OVER AND NEAR THE BLUE RIDGE WHERE INSTABILITY...
MOISTURE... AND LIFT WILL BE HIGHEST. HIGHS SHOULD REACH THE 88-93
RANGE.
THE CORE OF THE UPPER RIDGE IS FORECAST TO SHIFT SOUTHWEST WITH
TIME TO OVER THE GULF COAST STATES TUE-WED. THIS WILL ALLOW A WEAK
PIEDMONT TROUGH AT THE SURFACE WHICH MAY AID IN THE DEVELOPMENT OF
SCATTERED THUNDERSTORMS DURING THE AFTERNOON AND EVENING EARLY TO MID
WEEK. OTHERWISE... SIMPLY WARM AND HUMID WITH PARTLY CLOUDY SKIES.
LOWS 69-74. HIGHS 88-93 NW TO SANDHILLS.
FOR MID TO LATE WEEK... ANY SURFACE FRONT IS EXPECTED TO BE WEAK AND
PROVIDE LITTLE IF ANY COOLING OR DRYING. HOWEVER... IT MAY ACT AS A
CONTINUED FOCUS FOR SCATTERED MAINLY AFTERNOON THUNDERSTORMS WED-
FRI.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 130 PM FRIDAY...
A COLD FRONT HAS SHIFTED SOUTH THROUGH THE AREA THROUGHOUT THE DAY
TODAY...WITH FAIRLY EXTENSIVE CLOUD COVER ALONG AND NORTH OF THE
BOUNDARY...WITH MOSTLY CLEAR SKIES SOUTH OF THE FRONT (I.E. EXTREME
SOUTHERN PORTIONS OF THE FORECAST AREA...KFAY). THESE MVFR CIGS HAVE
PERSISTED ALL DAY AND WILL LIKELY PERSIST FOR AT LEAST THE NEXT
COUPLE OF HOURS. SOME BREAKS THIS AFTERNOON ARE STILL POSSIBLE...
WITH A BRIEF RETURN TO VFR CONDITIONS INTO THE EVENING HOURS.
HOWEVER...THE MOIST AIR MASS AND LIGHT AND VARIABLE WINDS OVERNIGHT
SHOULD RESULT IN FOG/LOW STRATUS DEVELOPMENT...WITH IFR/LIFR
CONDITIONS EXPECTED (ESPECIALLY TOWARDS THE NORTHEASTERN PORTIONS OF
THE FORECAST AREA...KRWI...KRDU). CONDITIONS ARE EXPECTED TO IMPROVE
TO VFR BY MID SATURDAY MORNING AS THE FRONT GRADUALLY WASHES OUT
OVER THE AREA. AN ISOLATED SHOWER OR STORM WILL BE POSSIBLE LATER
THIS AFTERNOON/EVENING AND AGAIN SATURDAY AFTERNOON...ALTHOUGH
COVERAGE WILL RATHER SPARSE.
OUTLOOK...A SUMMERTIME PATTERN WILL PERSIST THROUGH EARLY/MID NEXT
WEEK...WITH ISOLATED TO SCATTERED AFTERNOON/EVENING CONVECTION AND A
POTENTIAL FOR EARLY MORNING FOG/STRATUS.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...KRD
SHORT TERM...VINCENT
LONG TERM...PWB
AVIATION...KRD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1238 PM EDT FRI AUG 29 2014
.SYNOPSIS...A SLOW MOVING BACK DOOR COLD FRONT WILL STALL OUT ACROSS
CENTRAL NORTH CAROLINA TODAY. THE FRONT WILL GRADUALLY DISSIPATE
OVER THE WEEKEND AS A LIGHT SOUTHERLY RETURN FLOW DEVELOPS ACROSS
THE REGION.
&&
.NEAR TERM /TODAY AND TONIGHT/...
AS OF 1230 PM FRIDAY...
AS OF 16Z...LATEST OBSERVATIONS/ANALYSIS INDICATES THE SURFACE FRONT
HAS MADE IT THROUGH 2/3RDS THE FORECAST AREA. EXTENSIVE CLOUD COVER
IS NOTED WITHIN THE NORTHEASTERLY FLOW ALONG AND NORTH OF THE
FRONT...WITH MOSTLY CLEAR SKIES ACROSS THE EXTREME SOUTH. THERE
STILL IS A GREAT LEVEL OF DISAGREEMENT AMONG THE MODELS WITH RESPECT
TO THE EVOLUTION OF THIS CLOUD COVER...WITH THE NAM KEEPING THE
NORTHERN HALF OF THE FORECAST AREA MOSTLY CLOUDY ALL DAY AND THE GFS
AND RAP BREAKING OUT THE CLOUDS SOME WITH MORE IN THE WAY OF
EASTERLY/SOUTHEASTERLY FLOW LATER TODAY. HOWEVER...THE CLOUDS ARE
HANGING IN AND TEMPS REMAINED IN THE 70S ACROSS MUCH OF THE NORTHERN
TIER...MORE SIMILAR TO THE NAM. SENT OUT AN UPDATE TO REFLECT ALL OF
THIS...WITH HIGHS NOW EXPECTED TO BE IN THE LOW/MID 80S ACROSS THE
NORTH TO THE LOWER 90S ACROSS THE EXTREME SOUTH. WITH REGARDS TO
PRECIP CHANCES...ISOLATED TO SCATTERED CONVECTION IS STILL EXPECTED
LATER THIS AFTERNOON... ESPECIALLY IN THE VICINITY OF THE
FRONT...HOWEVER RECENT MODELS TRENDS ARE SHOWING VERY LITTLE IN THE
WAY OF COVERAGE. OVERNIGHT LOWS WILL GENERALLY RANGE FROM THE UPPER
60S ACROSS THE NORTH TO THE LOWER 70S FURTHER SOUTH.
&&
.SHORT TERM /SATURDAY AND SATURDAY NIGHT/...
AS OF 220 AM FRIDAY...
CENTRAL NC WILL REMAIN UNDER THE INFLUENCE OF AN UPPER LEVEL RIDGE
SAT/SAT NIGHT AS THE CENTER OF THE RIDGE CURRENTLY OVER THE
SOUTHEAST STATES SHIFTS SLIGHTLY EAST TOWARD THE COAST. THE
LINGERING FRONTAL ZONE OVER PORTIONS OF CENTRAL NC SHOULD WASH OUT
DURING THE DAY AS A LIGHT S/SE RETURN FLOW DEVELOPS ACROSS THE
REGION. FORECAST SOUNDINGS SUGGEST MARGINAL DESTABILIZATION WITH 500-
1500 J/KG OF MLCAPE SAT AFTERNOON. GIVEN A PROTOTYPICAL SUMMERTIME
`RIDGE` PATTERN...EXPECT ABOVE NORMAL TEMPS...IN THE LOWER 90S.
MARGINAL INSTABILITY AND SEASONABLE MOISTURE (PWAT VALUES OF 1.50-
1.75") WOULD SUPPORT ISOLD CONVECTION ON SATURDAY...THOUGH FORCING
FOR ASCENT WILL BE LIMITED TO THE SEABREEZE AND DIFFERENTIAL
HEATING...PRIMARILY ALONG THE HIGHER TERRAIN IN WESTERN NC...AND IT
IS POSSIBLE THAT NO CONVECTION WILL DEVELOP IN CENTRAL NC. WITH THE
ABOVE IN MIND...WILL INDICATE A SLIGHT CHANCE OF CONVECTION DURING
THE AFT AND EARLY EVE HOURS IN THE WESTERN PIEDMONT AND SE COASTAL
PLAIN. EXPECT NEAR NORMAL LOWS SAT NIGHT IN THE UPPER 60S TO LOWER
70S. -VINCENT
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 245 AM FRIDAY...
A RIDGE WILL BUILD OVER THE SOUTHEASTERN STATES EARLY TO MID WEEK.
THIS WILL EXTEND OUR CURRENT MORE SUMMER-LIKE PATTERN ACROSS NC WELL
INTO WEDNESDAY. THE CORE OF THE UPPER RIDGE IS FORECAST TO BE OVER
THE NC/SC COAST SUNDAY. THE APPROACHING UPPER TROUGH FROM THE OHIO
VALLEY WILL BE DEFLECTED TO OUR NORTH AND WEAKEN SUNDAY NIGHT AND
MONDAY. EVEN WITH THE HEAT AND HUMIDITY WITH THE SOUTHERLY RETURN
FLOW... ONLY ISOLATED AFTERNOON THUNDERSTORMS ARE EXPECTED. THE BEST
CHANCE IS FORECAST OVER AND NEAR THE BLUE RIDGE WHERE INSTABILITY...
MOISTURE... AND LIFT WILL BE HIGHEST. HIGHS SHOULD REACH THE 88-93
RANGE.
THE CORE OF THE UPPER RIDGE IS FORECAST TO SHIFT SOUTHWEST WITH
TIME TO OVER THE GULF COAST STATES TUE-WED. THIS WILL ALLOW A WEAK
PIEDMONT TROUGH AT THE SURFACE WHICH MAY AID IN THE DEVELOPMENT OF
SCATTERED THUNDERSTORMS DURING THE AFTERNOON AND EVENING EARLY TO MID
WEEK. OTHERWISE... SIMPLY WARM AND HUMID WITH PARTLY CLOUDY SKIES.
LOWS 69-74. HIGHS 88-93 NW TO SANDHILLS.
FOR MID TO LATE WEEK... ANY SURFACE FRONT IS EXPECTED TO BE WEAK AND
PROVIDE LITTLE IF ANY COOLING OR DRYING. HOWEVER... IT MAY ACT AS A
CONTINUED FOCUS FOR SCATTERED MAINLY AFTERNOON THUNDERSTORMS WED-
FRI.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
AS OF 730 AM FRIDAY...
24-HR TAF PERIOD: BELOW AVERAGE CONFIDENCE IN THE FORECAST THROUGH
TONIGHT. THE NAM MODEL GUIDANCE BEST MATCHES THE LATEST OBS DATA...
WHICH SUGGESTS THE NORTHERN TERMINALS (INT/GSO/RDU/RWI) WILL BE
AFFECTED BY PERIODIC OR PERSISTENT IFR/MVFR CEILINGS THIS MORNING...
WITH IMPROVEMENT TO MVFR DURING THE AFTERNOON. MVFR CEILINGS AND
ISOLD CONVECTION WILL BE POSSIBLE THROUGH THE AFTERNOON AND EVENING
HOURS. GIVEN THE LATEST TRENDS...A MORE PESSIMISTIC FORECAST MAY BE
NECESSARY TONIGHT THROUGH SAT MORNING AT THE NORTHERN TERMINALS
WHERE CONDITIONS MAY DETERIORATE TO IFR/LIFR OVERNIGHT BEFORE
GRADUALLY IMPROVING TO VFR BY SAT AFTERNOON.
LOOKING AHEAD: EXPECT A NEAR CLIMATOLOGICAL PATTERN THROUGH EARLY
NEXT WEEK WITH A SLIGHT CHANCE OF AFTERNOON/EVENING CONVECTION AND A
POTENTIAL FOR EARLY MORNING FOG/STRATUS. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...KRD
SHORT TERM...VINCENT
LONG TERM...PWB
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1005 AM EDT FRI AUG 29 2014
.SYNOPSIS...A SLOW MOVING BACK DOOR COLD FRONT WILL STALL OUT ACROSS
CENTRAL NORTH CAROLINA TODAY. THE FRONT WILL GRADUALLY DISSIPATE
OVER THE WEEKEND AS A LIGHT SOUTHERLY RETURN FLOW DEVELOPS ACROSS
THE REGION.
&&
.NEAR TERM /TODAY AND TONIGHT/...
AS OF 1000 AM FRIDAY...
AS OF 13Z...LATEST OBSERVATIONS/ANALYSIS INDICATES THE SURFACE FRONT
IS BISECTING THE FORECAST AREA. EXTENSIVE CLOUD COVER IS NOTED
WITHIN THE NORTHEASTERLY FLOW ALONG AND NORTH OF THE FRONT...WITH
MOSTLY CLEAR SKIES TO THE SOUTH. THERE STILL IS A GREAT LEVEL OF
DISAGREEMENT AMONG THE MODELS WITH RESPECT TO THE EVOLUTION OF THIS
CLOUD COVER...WITH THE NAM KEEPING THE NORTHERN HALF OF THE FORECAST
AREA MOSTLY CLOUDY ALL DAY AND THE GFS AND RAP BREAKING OUT THE
CLOUDS WITH MORE IN THE WAY OF EASTERLY/SOUTHEASTERLY FLOW LATER
TODAY. BEING THERE ARE ALREADY INDICATIONS OF SOME BREAKS IN THE
CLOUDS (VIA VISIBLE SATELLITE)...WILL FOLLOW CLOSER TO THE GFS AND
RAP BUT WILL STILL SHOW SOME ENHANCED CLOUD COVER ACROSS NORTH. THIS
WILL HAVE AN IMPACT ON HIGH TEMPS (ACROSS THE NORTH) TODAY...AS THE
NAM SHOWS HIGHS ONLY REACHING THE UPPER 70/LOWER 80S...WITH UPPER
80S INDICATED BY THE OTHER MODELS. THEREFORE...WILL TREND THE HIGHS
UPWARD ACROSS THE NORTH...BUT ONLY INTO THE MID 80S. WITH REGARDS TO
PRECIP CHANCES...ISOLATED TO SCATTERED CONVECTION IS EXPECTED LATER
THIS AFTERNOON...ESPECIALLY IN THE VICINITY OF THE FRONT. OVERNIGHT
LOWS WILL GENERALLY RANGE FROM THE UPPER 60S ACROSS THE NORTH TO THE
LOWER 70S FURTHER SOUTH.
&&
.SHORT TERM /SATURDAY AND SATURDAY NIGHT/...
AS OF 220 AM FRIDAY...
CENTRAL NC WILL REMAIN UNDER THE INFLUENCE OF AN UPPER LEVEL RIDGE
SAT/SAT NIGHT AS THE CENTER OF THE RIDGE CURRENTLY OVER THE
SOUTHEAST STATES SHIFTS SLIGHTLY EAST TOWARD THE COAST. THE
LINGERING FRONTAL ZONE OVER PORTIONS OF CENTRAL NC SHOULD WASH OUT
DURING THE DAY AS A LIGHT S/SE RETURN FLOW DEVELOPS ACROSS THE
REGION. FORECAST SOUNDINGS SUGGEST MARGINAL DESTABILIZATION WITH 500-
1500 J/KG OF MLCAPE SAT AFTERNOON. GIVEN A PROTOTYPICAL SUMMERTIME
`RIDGE` PATTERN...EXPECT ABOVE NORMAL TEMPS...IN THE LOWER 90S.
MARGINAL INSTABILITY AND SEASONABLE MOISTURE (PWAT VALUES OF 1.50-
1.75") WOULD SUPPORT ISOLD CONVECTION ON SATURDAY...THOUGH FORCING
FOR ASCENT WILL BE LIMITED TO THE SEABREEZE AND DIFFERENTIAL
HEATING...PRIMARILY ALONG THE HIGHER TERRAIN IN WESTERN NC...AND IT
IS POSSIBLE THAT NO CONVECTION WILL DEVELOP IN CENTRAL NC. WITH THE
ABOVE IN MIND...WILL INDICATE A SLIGHT CHANCE OF CONVECTION DURING
THE AFT AND EARLY EVE HOURS IN THE WESTERN PIEDMONT AND SE COASTAL
PLAIN. EXPECT NEAR NORMAL LOWS SAT NIGHT IN THE UPPER 60S TO LOWER
70S. -VINCENT
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 245 AM FRIDAY...
A RIDGE WILL BUILD OVER THE SOUTHEASTERN STATES EARLY TO MID WEEK.
THIS WILL EXTEND OUR CURRENT MORE SUMMER-LIKE PATTERN ACROSS NC WELL
INTO WEDNESDAY. THE CORE OF THE UPPER RIDGE IS FORECAST TO BE OVER
THE NC/SC COAST SUNDAY. THE APPROACHING UPPER TROUGH FROM THE OHIO
VALLEY WILL BE DEFLECTED TO OUR NORTH AND WEAKEN SUNDAY NIGHT AND
MONDAY. EVEN WITH THE HEAT AND HUMIDITY WITH THE SOUTHERLY RETURN
FLOW... ONLY ISOLATED AFTERNOON THUNDERSTORMS ARE EXPECTED. THE BEST
CHANCE IS FORECAST OVER AND NEAR THE BLUE RIDGE WHERE INSTABILITY...
MOISTURE... AND LIFT WILL BE HIGHEST. HIGHS SHOULD REACH THE 88-93
RANGE.
THE CORE OF THE UPPER RIDGE IS FORECAST TO SHIFT SOUTHWEST WITH
TIME TO OVER THE GULF COAST STATES TUE-WED. THIS WILL ALLOW A WEAK
PIEDMONT TROUGH AT THE SURFACE WHICH MAY AID IN THE DEVELOPMENT OF
SCATTERED THUNDERSTORMS DURING THE AFTERNOON AND EVENING EARLY TO MID
WEEK. OTHERWISE... SIMPLY WARM AND HUMID WITH PARTLY CLOUDY SKIES.
LOWS 69-74. HIGHS 88-93 NW TO SANDHILLS.
FOR MID TO LATE WEEK... ANY SURFACE FRONT IS EXPECTED TO BE WEAK AND
PROVIDE LITTLE IF ANY COOLING OR DRYING. HOWEVER... IT MAY ACT AS A
CONTINUED FOCUS FOR SCATTERED MAINLY AFTERNOON THUNDERSTORMS WED-
FRI.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
AS OF 730 AM FRIDAY...
24-HR TAF PERIOD: BELOW AVERAGE CONFIDENCE IN THE FORECAST THROUGH
TONIGHT. THE NAM MODEL GUIDANCE BEST MATCHES THE LATEST OBS DATA...
WHICH SUGGESTS THE NORTHERN TERMINALS (INT/GSO/RDU/RWI) WILL BE
AFFECTED BY PERIODIC OR PERSISTENT IFR/MVFR CEILINGS THIS MORNING...
WITH IMPROVEMENT TO MVFR DURING THE AFTERNOON. MVFR CEILINGS AND
ISOLD CONVECTION WILL BE POSSIBLE THROUGH THE AFTERNOON AND EVENING
HOURS. GIVEN THE LATEST TRENDS...A MORE PESSIMISTIC FORECAST MAY BE
NECESSARY TONIGHT THROUGH SAT MORNING AT THE NORTHERN TERMINALS
WHERE CONDITIONS MAY DETERIORATE TO IFR/LIFR OVERNIGHT BEFORE
GRADUALLY IMPROVING TO VFR BY SAT AFTERNOON.
LOOKING AHEAD: EXPECT A NEAR CLIMATOLOGICAL PATTERN THROUGH EARLY
NEXT WEEK WITH A SLIGHT CHANCE OF AFTERNOON/EVENING CONVECTION AND A
POTENTIAL FOR EARLY MORNING FOG/STRATUS. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...KRD
SHORT TERM...VINCENT
LONG TERM...PWB
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
954 AM EDT FRI AUG 29 2014
.SYNOPSIS...
STRENGTHENING BERMUDA HIGH PRESSURE OVER THE WESTERN ATLANTIC WILL
BRING TYPICAL LATE SUMMER WEATHER CONDITIONS ACROSS THE AREA. WARMTH
WILL CONTINUE ALONG WITH ISOLATED THUNDERSTORMS OVER THE LABOR DAY
WEEKEND. A WEAK FRONT WILL STALL NEAR THE COAST NEXT WEEK INCREASING
OUR RAIN CHANCES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 952 AM FRIDAY...A COLD FRONT HAS REACHED A LINE FROM SOUTH
OF CHARLOTTE TO GOLDSBORO AND EAST TO THE OUTER BANKS. THIS
BOUNDARY IS DEPICTED WELL IN THE 925 MB THETA FIELD. THE 13 UTC
RUC IS SHOWING THE EAST-WEST THETA GRADIENT DISSIPATING WITH THE
AFTERNOON HEATING. MORNING SOUNDINGS AND THE BLENDED TOTAL
PRECIPITABLE WATER IS SHOWING A MOISTURE GRADIENT FROM 1.6 INCHES
TO THE NORTH TO 1.25 INCHES IN THE SOUTH. WITH THE BEST MOISTURE
TO OUR NORTH. THE 12 UTC HRRR REFLECTIVITY FIELD IS DEPICTING
SCATTERED AFTERNOON CONVECTION DEVELOPING JUST NORTH OF SOUTHEAST
NORTH CAROLINA AND REMAINING DRY OVER THE FORECAST AREA. THUS AT
THIS TIME WILL KEEP THE FORECAST RAIN FREE.
FORECAST HIGHS WILL REMAIN THE SAME WITH HIGHS REACHING THE MIDDLE
90S MAINLY WEST OF LUMBERTON TO ANDREWS AND LOWER 90S CLOSER TO
THE COAST. THERE WILL BE A FEW UPPER 80S ALONG THE IMMEDIATE BEACHES.
CALM WINDS ARE EXPECTED OVERNIGHT AND WITH HIGH PRESSURE TO THE
NORTH...WINDS WILL SHIFT TO AN ONSHORE FLOW. THIS WILL INCREASE
THE LOW LEVEL MOISTURE AND IT IS EXPECTED TO INCREASE THE
PROBABILITY OF FOG AND LOW STRATUS OVERNIGHT. LOWS OVERNIGHT ARE
EXPECTED TO FALL TO AROUND 70.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 AM FRIDAY...NOT A LOT OF CHANGES WARRANTED FOR THE SHORT
TERM FORECAST AS HIGH PRESSURE WILL DOMINATE THROUGH ALL LEVELS OF
THE ATMOSPHERE. GUIDANCE IS STILL SHOWING A RATHER WEAK SIGNAL FOR
MOSTLY SEA BREEZE CONVECTION AND HAVE MAINTAINED THESE MINIMAL POPS
IN THE FORECAST. PERHAPS A FEW MORE MID LEVEL CLOUDS WILL ADVANCE ON
THE REGION SUNDAY AFTERNOON AND EVENING AS THE SYSTEM NOW LIGHTING
UP THE CENTRAL PLAINS SLOWLY MAKES IT EAST. TEMPERATURE
FORECAST/GUIDANCE WARRANTS ONLY TOKEN CHANGES AS UPPER 80S ALONG THE
COASTAL AREAS AND LOWER 90S INLAND CONTINUE. 70S FOR MORNING LOWS.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 300 AM FRIDAY...THE MID LEVEL PATTERN WILL CONTINUE TO BE
DOMINATED BY RIDGING AS BASICALLY A ZONAL FLOW DEVELOPS. AN
ELONGATED RIDGE WILL BUILD EAST TO WEST BY THE END OF THE PERIOD
TRANSITIONING FROM A MORE AMPLIFIED PATTERN EARLY IN THE WEEK. AT THE
SURFACE...NOTABLE FEATURES WILL BE HIGH PRESSURE ACROSS THE
SOUTHEAST AND THE PIEDMONT TROUGH CLOSER TO OUR AREA. THERE WILL BE
POPS ESSENTIALLY EVERY DAY WITH THE BEST CHANCES TUESDAY AND
WEDNESDAY WHEN THE SURFACE FEATURES GET AN ASSIST FROM THE UPPER
LEVELS. THE TIMING HOWEVER IS LOWER CONFIDENCE. WITH THE PERIOD
MODULATED BY HIGH PRESSURE BOTH AT THE SURFACE AND ALOFT...NO
SURPRISE THAT TEMPERATURES BOTH MAX AND MINS WILL BE ABOVE
NORMAL...BY JUST ABOUT A CATEGORY ACROSS THE BOARD.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
AS OF 12Z...EXPECT VFR CONDITIONS THROUGH MUCH OF THE FORECAST
PERIOD WITH WEST TO SOUTHWEST WINDS AROUND 5 KT THIS AM BECOMING S
TO SE AT 5 TO 10 KT THIS AFTERNOON BEFORE DIMINISHING TONIGHT. WITH
THE S TO SE FLOW...AN INCREASE IN LOW LEVEL MOISTURE IS EXPECTED
THIS AFTERNOON INTO TONIGHT SUCH THAT FOG MAY DEVELOP OVERNIGHT.
FOR NOW...TAFS HAVE MVFR FOG AND SCATTERED CLOUDS AT 500 FEET BUT
THERE IS THE POTENTIAL FOR IFR FOG AFTER 06Z.
EXTENDED OUTLOOK...MORNING FOG WITH MVFR/IFR CONDITIONS POSSIBLE
SATURDAY. A SLIGHT CHANCE OF SHOWERS WITH MVFR FOR OUR NORTHERN
TERMINALS SAT. INCREASING CHANCES FOR PRECIP SUNDAY THROUGH TUESDAY
WITH MVFR CONDITIONS POSSIBLE.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 952 AM FRIDAY...CURRENTLY A WEST-SOUTHWEST FLOW OF 5 TO 10
KNOTS IS BLOWING OVER THE COASTAL WATERS WITH 2 TO 2.5 FT WAVES.
THE BUOYS ARE PICKING UP A 1/3 FOOT SWELL FROM THE EAST SOUTHEAST
THIS MORNING AND THE WAVE WATCH IS SHOWING THIS DECREASING WITH
TIME. AS A FRONTAL BOUNDARY STALLING TO THE NORTH OF THE WATERS
THE PRESSURE GRADIENT IS WEAK AND WIND SPEED ARE NOT EXPECTED TO
INCREASE OVERNIGHT.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 AM FRIDAY...SOUTH TO SOUTHEAST WINDS WILL CONTINUE FOR
MOST OF THE PERIOD ON THE ORDER OF 10-15 KNOTS. THERE MAY BE A
SLIGHT VEERING TO SOUTHWEST LATE SUNDAY INTO MONDAY MORNING AS A
SYSTEM CREEPS IN FROM THE WEST BUT THIS WILL BE A VERY GRADUAL
TRANSITION. SWAN SEAS SHOW A CONSISTENT 1-3 FEET THROUGHOUT THE
PERIOD.
LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 300 AM FRIDAY...LATE SUMMERTIME PATTERN WILL BE IN FULL FORCE
ACROSS THE COASTAL WATERS. SOUTH TO SOUTHWEST WINDS OF 10-15 KNOTS
WILL PREVAIL WITH A SLIGHT INCREASE DURING THE AFTERNOON HOURS.
SIGNIFICANT SEAS...NOW VOID OF ANY SIGNIFICANT SWELL COMPONENT WILL
BE 1-3 FEET.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HAWKINS
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...RAN
AREA FORECAST DISCUSSION
NWS RALEIGH NC
158 AM EDT FRI AUG 29 2014
.SYNOPSIS...A SLOW MOVING BACK DOOR COLD FRONT IN SOUTHERN VIRGINIA
WILL STALL OUT NEAR OR JUST SOUTH OF THE NORTH CAROLINA BORDER
TODAY. THE FRONT WILL GRADUALLY DISSIPATE OVER THE WEEKEND AS A
LIGHT SOUTHERLY RETURN FLOW DEVELOPS ACROSS THE REGION.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1015 PM THURSDAY...
THE BACKDOOR SEGMENT OF THE COLD FRONT ORIENTED FROM NW TO SE ACROSS
SOUTH-CENTRAL VA HAS MAINTAINED A BAND OF WEAK CONVECTION CENTERED
NEAR FARMVILLE...VA FOR THE PAST SEVERAL HOURS. A PRECEDING...PRE-
FRONTAL TROUGH DRAPED ACROSS CENTRAL NC HAS BEEN DEVOID OF ANY SUCH
ACTIVITY...HOWEVER...DESPITE A RIBBON OF LOW-MID LEVEL MOISTURE
CONVERGENCE AND WEAK AND SEEMINGLY UNINHIBITED ML INSTABILITY PER
00Z GSO AND MHX RAOB DATA. RECENT RUNS OF THE HRRR CONTINUE TO
SUGGEST THE CONVECTION OVER SOUTH-CENTRAL VA WILL DRIFT SOUTH ACROSS
THE NORTHEAST PIEDMONT AND NORTHERN COASTAL PLAIN...AND SUCH A
SCENARIO SEEMS PLAUSIBLE GIVEN THE ENVIRONMENT DESCRIBED ABOVE. WILL
CONSEQUENTLY MAINTAIN A SLIGHT-SMALL CHANCE OF A SHOWER OR STORM
THERE OVERNIGHT. THE OTHER...AND HIGHER PROBABILITY...CONCERNS
INCLUDE THE DEVELOPMENT OF AREAS OF FOG...OWING TO SAID LOW LEVEL
MOISTURE POOLING ALONG THE PRE-FRONTAL TROUGH AXIS...AND LOW CLOUDS
IN POST-FRONTAL NE LOW LEVEL FLOW ONCE THE FRONT SETTLES SOUTH INTO
THE SANDHILLS AND SOUTHERN PIEDMONT BY EARLY FRI. IN FACT...A LOW
OVERCAST IS APT TO DEVELOP GENERALLY ALONG AND NORTH OF HWY 64 VERY
LATE TONIGHT THROUGH EARLY FRI. IF THE LOW CLOUDS INDEED
MATERIALIZE...THEIR DISPERSION THROUGHOUT THE DAY FRI WOULD BE SLOW
OWING A TRAPPING FRONTAL INVERSION BEHIND THE SOUTHWARD-SETTLING
FRONT...WHICH COULD IMPACT HIGH TEMPS FRI. LOWS TONIGHT IN THE MID
60S TO LOW 70S.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 200 PM THURSDAY...
FRIDAY AND FRIDAY NIGHT: THE UPPER LEVEL RIDGE WILL AMPLIFY OVER THE
MID-ATLANTIC ON FRIDAY. AT THE SURFACE...THE FRONT WILL BE STALLED
IN THE VICINITY OF THE NC/VA BORDER DURING THE DAY BEFORE SLOWLY
RETREATING TO THE NE OVERNIGHT. MUCH OF THE WEATHER WILL DEPEND ON
THE LOCATION OF THE FRONTAL BOUNDARY THROUGHOUT THE DAY. THE LOWER
TEMPS WILL BE ALONG AND NORTH OF THE FRONT...WITH HIGHER HIGHS
ACROSS THE SOUTH. ANY CONVECTION THAT DEVELOPS WILL BE MAINLY ALONG
AND SOUTH OF THE FRONT...BUT EXPECT COVERAGE TO BE ISOLATED AT BEST
AND CONFIDENCE THAT IT WILL DEVELOP IS NOT TERRIBLY HIGH AT THIS
TIME. CONTINUED MID LEVEL MOISTURE ADVECTION SHOULD RESULT IN CLOUDY
CONDITIONS THROUGH A GOOD PART OF THE DAY. NORTHEASTERLY WINDS ALONG
AND NORTH OF THE FRONT AND SOUTHWESTERLY SOUTH OF IT DURING THE
DAY/EVENING SHOULD BECOME GENERALLY SOUTHEASTERLY ACROSS THE AREA
OVERNIGHT. HIGHS EXPECTED TO RANGE FROM THE MID 80S NORTH TO LOW 90S
SOUTH. LOWS IN THE UPPER 80S TO AROUND 70 DEGREES. -KC
SATURDAY AND SATURDAY NIGHT: NORTH CAROLINA WILL STILL BE UNDER THE
INFLUENCE OF A STRONG UPPER LEVEL RIDGE AND AN EXITING SURFACE HIGH
PRESSURE TO THE NORTHEAST. THIS WILL KEEP WEATHER DRY AND SETTLED ON
SATURDAY AND SATURDAY AFTERNOON. CONDITIONS WILL BE STABLE AND A
SLIGHT DECREASE IN MOISTURE MAY HELP HIGH TEMPERATURES TO REACH THE
LOWER 90S IN MOST LOCATIONS WITH UPPER 80S ACROSS THE NORTHERN
COUNTIES. WINDS WILL BE OUT OF THE SOUTH AT AROUND 5 KTS GUSTING TO
10 KTS. THE HIGH WILL CONTINUE TO MOVE OFFSHORE SATURDAY
NIGHT...ALLOWING MOISTURE TRANSPORT OUT OF THE GULF OF MEXICO TO
INCREASE AS A DISSIPATING LOW PRESSURE SYSTEM MOVES EASTWARD OUT OF
THE NORTHERN PLAINS AND INTO THE GREAT LAKES REGION. THIS WILL SET
THE STAGE FOR A MORE UNSETTLED PATTERN BEGINNING ON SUNDAY. LOWS
SATURDAY NIGHT UPPER 60S TO LOWER 70S. -ELLIS
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 245 PM THURSDAY...
SUNDAY THROUGH TUESDAY NIGHT: A MORE UNSETTLED PERIOD OF WEATHER
WILL BEGIN ON SUNDAY WITH HIGH PRESSURE OFFSHORE SETTING UP A RETURN
FLOW REGIME OVER CENTRAL NC THAT WILL TRANSPORT MOISTURE INTO THE
AREA FROM THE GULF OF MEXICO AND SOUTHWESTERN ATLANTIC. AS PW VALUES
CREEP UP OVER TWO INCHES THE CHANCES FOR CONVECTION WILL
INCREASE...MAINLY DRIVEN BY INSTABILITY DURING THE DIURNALLY
FAVORABLE TIMES AS SHEAR WILL REMAIN VERY WEAK. HIGH TEMPERATURES
ARE EXPECTED TO RISE INTO THE LOWER 90S EACH DAY WITH LOWS IN THE
LOWER 70S.
WEDNESDAY AND THURSDAY: A MORE DEFINED FRONTAL SYSTEM WILL MOVE IN
ON WEDNESDAY AS LOW PRESSURE MOVES THROUGH SOUTHERN QUEBEC AND A
STRONG SURFACE HIGH BUILDS IN OVER THE GREAT LAKES AND EXTENDING
DOWN INTO THE OHIO VALLEY. WITH THE LOW RAPIDLY MOVING OFF TO THE
NORTHEAST...FORCING ALONG THE ATTENDANT COLD FRONT WILL REMAIN WEAK
AS SHOWN BY SMALL STRAIGHT HODOGRAPHS THROUGH THE LOWEST 6KM ON
MODEL FORECAST SOUNDINGS. TIMING OF THE FRONT AND ASSOCIATED
PRECIPIATION IS IN QUESTION AT THIS TIME WITH MODELS HINTING AT A
LATE WEDNESDAY/EARLY THURSDAY ARRIVAL AND THEN STALLING OUT
SOMEWHERE OVER THE AREA FOR LATE WEEK. MOST CONVECTIVE ACTIVITY WILL
REMAIN DIURNAL WITH THE SLIGHT CHANCES OVERNIGHT. TEMPERATURES
SLIGHTLY COOLER WITH MORE ANTICIPATED CLOUD COVER AND SLIGHT AIRMASS
CHANGE. UPPER 80S TO NEAR 90 FOR HIGHS WITH LOWS UPPER 60S TO NEAR
70 DEGREES.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 150 AM FRIDAY...
24-HR TAF PERIOD: BELOW AVERAGE CONFIDENCE IN THE FORECAST THROUGH
TONIGHT. A BACK DOOR COLD FRONT ORIENTED WEST-EAST ACROSS SOUTHERN
VA AT 06Z WILL MOVE SLOWLY SOUTH TOWARD THE NC BORDER TODAY...
EVENTUALLY STALLING OUT NEAR OR JUST SOUTH OF THE BORDER ACROSS THE
NORTHERN PIEDMONT. MODEL GUIDANCE CONTINUES TO VARY CONSIDERABLY
WITH REGARD TO CEILINGS AND PRECIP CHANCES TODAY INTO TONIGHT. THE
00Z NAM INDICATES A HYBRID COLD AIR DAMMING WEDGE WITH MVFR/IFR
CEILINGS AND ELEVATED SHOWER ACTIVITY DEVELOPING BETWEEN 12-18Z AT
ALL OF THE NORTHERN TERMINALS (INT/GSO/RDU/RWI)...WHILE THE GFS
INDICATES VFR CONDITIONS PREVAILING OUTSIDE OF MVFR CONDITIONS
ASSOC/W ISOLD SFC-BASED CONVECTION. WITH LITTLE INDICATION ONE WAY
OR THE OTHER...WILL SPLIT THE DIFFERENCE AND INTRODUCE A TEMPO GROUP
FOR BKN015 BETWEEN 12-16Z EVERYWHERE EXCEPT THE FAY TERMINAL.
LOOKING AHEAD: EXPECT A NEAR CLIMATOLOGICAL PATTERN THROUGH EARLY
NEXT WEEK WITH A SLIGHT CHANCE OF AFTERNOON/EVENING CONVECTION AND A
POTENTIAL FOR EARLY MORNING FOG/STRATUS. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...MWS
SHORT TERM...KC/ELLIS
LONG TERM...ELLIS
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1241 PM CDT FRI AUG 29 2014
.UPDATE...
ISSUED AT 1242 PM CDT FRI AUG 29 2014
CURRENT VIS SAT SHOWING WIDENING CLEARING OVER THE SOUTH CENTRAL
PORTION OF NORTH DAKOTA...RIGHT AHEAD OF THE SFC TROUGH. HAVE
REDUCED POPS ELSE WHERE ACROSS THE CWA AND INCREASED TO ABOUT 40S
THE POPS OVER SOUTHEASTERN ND. SKIES ACROSS EAST CENTRAL AND
NORTHEAST ND ARE BEGINNING TO THIN AS WELL...HOWEVER TEMPS ARE
STILL A GOOD 5 DEG COOLER SO WILL HOLD OFF ON INCREASING POPS AT
THIS POINT. NO OTHER CHANGES TO IMMEDIATE SHORT TERM FOR THIS UPDATE.
UPDATE ISSUED AT 952 AM CDT FRI AUG 29 2014
CURRENT RADAR SHOWING SOME WEAK SHOWERS OVER THE FAR SOUTHERN
VALLEY DRIFTING OUT OF CWA. ALSO A STRONG STORM SOUTH OF MANITOBA
MOVING EASTWARD ACROSS SOUTHERN MANITOBA AND NOT EXPECTED TO DROP
INTO THE CONUS...HOWEVER WILL NEED TO WATCH LOW COUNTY IF IT HOLDS
TOGETHER THAT LONG. MAIN ISSUE TODAY WILL BE CLOUDS. WHILE THE NAM
SEEMS RATHER BULLISH WITH QPFS ASSOCIATED WITH ACTIVITY ACROSS
EASTERN SD AND NORTH CENTRAL/EASTERN MN...POPS FOR THE SHARP SFC
TROUGH MOVING ACROSS THE CWA TODAY SEEM REASONABLE. WILL TREND
POPS TOWARD THE NAM SOLUTION FOR THIS AFTN. THERE ARE SOME SIGNS
OF SKY BREAKING UP ACROSS EASTERN ND THIS MORNING TO PROVIDE SOME
SOLAR FOR AFTN CONVECTION AS THE TROUGH MOVES THROUGH...HOWEVER
THIS ACTIVITY WILL BE VERY DEPENDENT ON HOW MUCH SOLAR CAN GET
THROUGH SO WILL LIMIT POPS TO LOW END OF CHANCE CATEGORY. ALSO
HAVE REMOVED THUNDER AS PREDOMINANT PTYPE AND CHANGED OVER TO RAIN
SHOWERS WITH ISOLD TSTMS. NO OTHER CHANGES EXPECTED THIS UPDATE.
UPDATE ISSUED AT 655 AM CDT FRI AUG 29 2014
NO SIG UPDATES NEEDED AT THIS TIME. BANDS OF LIGHT RAIN ARE MOVING
THROUGH THE BWP-FFM-PKD-BJI AREA IN THE DEFORMATION ZONE AT THE
AHEAD OF THE LOW PRESSURE SYSTEM NOW IN SOUTHWEST MN. MEANWHILE
A WINDSHIFT LINE IS APPARENT ON RADAR IMAGERY ALG A YWG-DVL-BIS
LINE SHOWING THE APPROACHING LOW PRESSURE SYSTEM NOW EDGING INTO
THE NORTHWEST CORNER OF THE FA. FOCUS FOR SHOWERS AND THUNDER
SHOULD SHIFT TO THIS SYSTEM FOR LATER IN THE DAY.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 415 AM CDT FRI AUG 29 2014
TODAY...AREAS OF LOW CLOUDS AND VERY LIGHT RAIN WILL SHIFT
EASTWARD FROM NORTHWEST MN THROUGH THE FORENOON... WITH SOME
PATCHY SUNSHINE POSSIBLE THROUGH THE MIDDAY PERIOD. A COLD FRONT
APPROACHING FROM SOUTHWEST MANITOBA WILL BRING INCREASING CLOUDS
INTO NORTHEAST ND DURING THE FORENOON AND PUSH THROUGH THE AREA
DURING THE AFTERNOON. EXPECT SCT SHOWERS AND AN ISOLATED
THUNDERSTORM OF TWO...WITH GUSTY NORTHWEST WINDS KICKING IN BEHIND
THE FRONT LATER TODAY. AS PER THREAT OF SEVERE STORMS TODAY...
WHILE DEEP LAYER SHEER IS WEAK TODAY AND DEEP MOISTURE ADVECTION
IS TIED UP BY THE MORE ORGANIZED SYSTEM IN THE CENTRAL PLAINS...
EXPECTED DAYTIME HEATING AND LOCALLY AVAILABLE MOISTURE LOOK TO
BE SUFFICIENT FOR 1000 TO 2000 J/KG OF CAPE BY MID AFTERNOON... SO
AN ISOLATED SEVERE STORM IS POSSIBLE. RUC COMPUTED 2 KM LAYERED VGP
APPROACHES 0.2 FROM 18 INTO 21Z WITH LAYERED CAPE EXCEEDING 500
J/KG... ALMOST ENOUGH FOR A BRIEF SPINUP TO OCCUR. CERTAINLY
WORTH PAYING ATTENTION TOO... THUS LATEST SPC DAY1 OUTLOOK
CONTAINS A /SEE TEXT/ OVER OUR AREA.
TONIGHT AND SATURDAY...EXPECT GENERAL POSTFRONTAL DRYING AND
SEASONABLY COOL OVERNIGHT TEMPERATURES ESPECIALLY OVER THE
NORTHERN HALF OF THE FA. SOME LINGER SHOWERS ARE POSSIBLE INTO THE
LATE EVENING OVER NORTH CENTRAL MN LAKES. SATURDAY SHOULD BE DRY
AND SEASONABLY WARM ...WITH SOUTHERLY RETURN FLOW INCREASING
THROUGH THE AFTERNOON... AHEAD OF THE NEXT APPROACHING SYSTEM.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 415 AM CDT FRI AUG 29 2014
SATURDAY NIGHT AND SUNDAY...LOW PRESSURE DIGS INTO THE WRN DKTAS
LATE ON SATURDAY WITH DEEP CONVECTION EXPECTED TO CROSS INTO
CENTRAL ND THROUGH MIDNIGHT. BY SUNDAY MORNING MOST OF THE
ACTIVITY WILL SHIFT INTO ERN ND AND THE RED RIVER VALLEY...
OVERSPREADING NORTHWEST MINNESOTA THROUGH THE FORENOON. WITH
MODELS IN GENERAL AGREEMENT ON PLACING THE SFC TROF ALG THE RRV
AROUND 18Z... WILL EXPECT DEEP CONVECTION AND THE POSSIBILITY FOR
ISOLATED SEVERE STORMS AND LOCALLY HEAVY RAINS ALG AND EAST OF THE
RRV DURING THE AFTERNOON... CONSISTENT WITH CURRENT SPC/WPC DAY3
OUTLOOKS.
MONDAY THROUGH THURSDAY...FLOW BEGINS TO TRANSITION TO MORE
WESTERLY THEN SOUTHWESTERLY AS A LARGE TROUGH OVER THE NORTHERN
PLAINS MONDAY MOVES OFF TO THE EAST AND THE NEXT SYSTEM DIGS INTO
THE PAC NW. THINK THAT THE BEST CHANCES FOR PRECIP WILL BE LATE IN
THE PERIOD AS THE NEXT SFC LOW TRAVELS THROUGH SOUTH DAKOTA AND
PUTS OUR CWA IN THE PRIME DEFORMATION ZONE FOR PRECIPITATION.
HOWEVER...THERE WILL BE SOME LINGERING PRECIP ON THE BACKSIDE OF
THE DEPARTING LOW ON MONDAY AND EVEN DURING THE MIDDLE OF THE WEEK
SOME MODELS ARE BREAKING OUT SPITS OF PRECIP IN SOUTHWEST FLOW
ALOFT. WILL CONTINUE TO KEEP THE LOW POPS THAT ALLBLEND GIVES US
BUT WILL REFINE LATER. TEMPS WILL BE NEAR SEASONAL AVERAGES
THROUGHOUT THE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1242 PM CDT FRI AUG 29 2014
SCATTERED IFR CONDITIONS SHOULD RISE INTO THE MVFR CATEGORY THIS
AFTERNOON. WINDS WILL SHIFT TO THE NORTH BEHIND THE FRONT AND GUST
INTO THE 20-25KT RANGE IN THE NORTH THROUGH 03Z. MVFR CIGS
SHOULD SLOWLY CLEAR OVERNIGHT IN ALL BUT THE FAR EAST/SOUTH. WINDS
WILL BECOME LIGHT AND VARIABLE SAT MORNING WITH HIGH PRESSURE
OVERHEAD.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...SPEICHER
SHORT TERM...GUST
LONG TERM...GUST/JR
AVIATION...DK
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
954 AM CDT FRI AUG 29 2014
.UPDATE...
ISSUED AT 952 AM CDT FRI AUG 29 2014
CURRENT RADAR SHOWING SOME WEAK SHOWERS OVER THE FAR SOUTHERN
VALLEY DRIFTING OUT OF CWA. ALSO A STRONG STORM SOUTH OF MANITOBA
MOVING EASTWARD ACROSS SOUTHERN MANITOBA AND NOT EXPECTED TO DROP
INTO THE CONUS...HOWEVER WILL NEED TO WATCH LOW COUNTY IF IT HOLDS
TOGETHER THAT LONG. MAIN ISSUE TODAY WILL BE CLOUDS. WHILE THE NAM
SEEMS RATHER BULLISH WITH QPFS ASSOCIATED WITH ACTIVITY ACROSS
EASTERN SD AND NORTH CENTRAL/EASTERN MN...POPS FOR THE SHARP SFC
TROUGH MOVING ACROSS THE CWA TODAY SEEM REASONABLE. WILL TREND
POPS TOWARD THE NAM SOLUTION FOR THIS AFTN. THERE ARE SOME SIGNS
OF SKY BREAKING UP ACROSS EASTERN ND THIS MORNING TO PROVIDE SOME
SOLAR FOR AFTN CONVECTION AS THE TROUGH MOVES THROUGH...HOWEVER
THIS ACTIVITY WILL BE VERY DEPENDENT ON HOW MUCH SOLAR CAN GET
THROUGH SO WILL LIMIT POPS TO LOW END OF CHANCE CATEGORY. ALSO
HAVE REMOVED THUNDER AS PREDOMINANT PTYPE AND CHANGED OVER TO RAIN
SHOWERS WITH ISOLD TSTMS. NO OTHER CHANGES EXPECTED THIS UPDATE.
UPDATE ISSUED AT 655 AM CDT FRI AUG 29 2014
NO SIG UPDATES NEEDED AT THIS TIME. BANDS OF LIGHT RAIN ARE MOVING
THROUGH THE BWP-FFM-PKD-BJI AREA IN THE DEFORMATION ZONE AT THE
AHEAD OF THE LOW PRESSURE SYSTEM NOW IN SOUTHWEST MN. MEANWHILE
A WINDSHIFT LINE IS APPARENT ON RADAR IMAGERY ALG A YWG-DVL-BIS
LINE SHOWING THE APPROACHING LOW PRESSURE SYSTEM NOW EDGING INTO
THE NORTHWEST CORNER OF THE FA. FOCUS FOR SHOWERS AND THUNDER
SHOULD SHIFT TO THIS SYSTEM FOR LATER IN THE DAY.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 415 AM CDT FRI AUG 29 2014
TODAY...AREAS OF LOW CLOUDS AND VERY LIGHT RAIN WILL SHIFT
EASTWARD FROM NORTHWEST MN THROUGH THE FORENOON... WITH SOME
PATCHY SUNSHINE POSSIBLE THROUGH THE MIDDAY PERIOD. A COLD FRONT
APPROACHING FROM SOUTHWEST MANITOBA WILL BRING INCREASING CLOUDS
INTO NORTHEAST ND DURING THE FORENOON AND PUSH THROUGH THE AREA
DURING THE AFTERNOON. EXPECT SCT SHOWERS AND AN ISOLATED
THUNDERSTORM OF TWO...WITH GUSTY NORTHWEST WINDS KICKING IN BEHIND
THE FRONT LATER TODAY. AS PER THREAT OF SEVERE STORMS TODAY...
WHILE DEEP LAYER SHEER IS WEAK TODAY AND DEEP MOISTURE ADVECTION
IS TIED UP BY THE MORE ORGANIZED SYSTEM IN THE CENTRAL PLAINS...
EXPECTED DAYTIME HEATING AND LOCALLY AVAILABLE MOISTURE LOOK TO
BE SUFFICIENT FOR 1000 TO 2000 J/KG OF CAPE BY MID AFTERNOON... SO
AN ISOLATED SEVERE STORM IS POSSIBLE. RUC COMPUTED 2 KM LAYERED VGP
APPROACHES 0.2 FROM 18 INTO 21Z WITH LAYERED CAPE EXCEEDING 500
J/KG... ALMOST ENOUGH FOR A BRIEF SPINUP TO OCCUR. CERTAINLY
WORTH PAYING ATTENTION TOO... THUS LATEST SPC DAY1 OUTLOOK
CONTAINS A /SEE TEXT/ OVER OUR AREA.
TONIGHT AND SATURDAY...EXPECT GENERAL POSTFRONTAL DRYING AND
SEASONABLY COOL OVERNIGHT TEMPERATURES ESPECIALLY OVER THE
NORTHERN HALF OF THE FA. SOME LINGER SHOWERS ARE POSSIBLE INTO THE
LATE EVENING OVER NORTH CENTRAL MN LAKES. SATURDAY SHOULD BE DRY
AND SEASONABLY WARM ...WITH SOUTHERLY RETURN FLOW INCREASING
THROUGH THE AFTERNOON... AHEAD OF THE NEXT APPROACHING SYSTEM.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 415 AM CDT FRI AUG 29 2014
SATURDAY NIGHT AND SUNDAY...LOW PRESSURE DIGS INTO THE WRN DKTAS
LATE ON SATURDAY WITH DEEP CONVECTION EXPECTED TO CROSS INTO
CENTRAL ND THROUGH MIDNIGHT. BY SUNDAY MORNING MOST OF THE
ACTIVITY WILL SHIFT INTO ERN ND AND THE RED RIVER VALLEY...
OVERSPREADING NORTHWEST MINNESOTA THROUGH THE FORENOON. WITH
MODELS IN GENERAL AGREEMENT ON PLACING THE SFC TROF ALG THE RRV
AROUND 18Z... WILL EXPECT DEEP CONVECTION AND THE POSSIBILITY FOR
ISOLATED SEVERE STORMS AND LOCALLY HEAVY RAINS ALG AND EAST OF THE
RRV DURING THE AFTERNOON... CONSISTENT WITH CURRENT SPC/WPC DAY3
OUTLOOKS.
MONDAY THROUGH THURSDAY...FLOW BEGINS TO TRANSITION TO MORE
WESTERLY THEN SOUTHWESTERLY AS A LARGE TROUGH OVER THE NORTHERN
PLAINS MONDAY MOVES OFF TO THE EAST AND THE NEXT SYSTEM DIGS INTO
THE PAC NW. THINK THAT THE BEST CHANCES FOR PRECIP WILL BE LATE IN
THE PERIOD AS THE NEXT SFC LOW TRAVELS THROUGH SOUTH DAKOTA AND
PUTS OUR CWA IN THE PRIME DEFORMATION ZONE FOR PRECIPITATION.
HOWEVER...THERE WILL BE SOME LINGERING PRECIP ON THE BACKSIDE OF
THE DEPARTING LOW ON MONDAY AND EVEN DURING THE MIDDLE OF THE WEEK
SOME MODELS ARE BREAKING OUT SPITS OF PRECIP IN SOUTHWEST FLOW
ALOFT. WILL CONTINUE TO KEEP THE LOW POPS THAT ALLBLEND GIVES US
BUT WILL REFINE LATER. TEMPS WILL BE NEAR SEASONAL AVERAGES
THROUGHOUT THE PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 415 AM CDT FRI AUG 29 2014
EXPECT -SHRA TO CONTINUE ACROSS THE FAR SRN VALLEY AND INTO LAKES
COUNTY. OTHERWISE MOST AREAS WILL SEE MVFR/IFR CIGS AND PATCHY FOG
THROUGH THE MORNING. AREAS MVFR CIGS LIKELY THROUGH MIDDAY AHEAD
OF A SFC COLD FRONT FORECAST TO CROSS THE AREA. SCT SHOWERS AND
ISOLATED THUNDERSTORMS ARE EXPECTED AHEAD OF THE FRONT THROUGH THE
AFTERNOON.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...SPEICHER
SHORT TERM...GUST
LONG TERM...GUST/JR
AVIATION...GUST
AREA FORECAST DISCUSSION
NWS BISMARCK ND
822 AM CDT FRI AUG 29 2014
.UPDATE...
ISSUED AT 813 AM CDT FRI AUG 29 2014
FRONTAL BOUNDARY CONTINUES TO MAKE ITS WAY THROUGH CENTRAL NORTH
DAKOTA. MOST SHOWERS ARE REMAINING POST FRONTAL AS MAIN UPPER
FORCING CONTINUES TO PUSH ITS WAY IN FROM EASTERN MONTANA. HAVE
UPPED PRECIPITATION CHANCES SOME WITH CURRENT TRENDS. WILL HAVE TO
KEEP AN EYE ON THE SOUTHERN JAMES RIVER VALLEY TOWARDS MID-DAY
INTO EARLY AFTERNOON FOR SOME STORMS DEVELOPING AND POSSIBLY
BECOMING STRONG AS MODELS CONTINUE TO SHOW INCREASING INSTABILITY
THROUGH THE DAY THOUGH THE SHEAR COMPONENT REMAINS MODEST. UPDATES
HAVE BEEN SENT.
UPDATE ISSUED AT 642 AM CDT FRI AUG 29 2014
COLD FRONT MAKING ITS WAY INTO CENTRAL NORTH DAKOTA WITH VERY
LIMITED CONVECTION ALONG IT. POST FRONTAL SHOWERS CONTINUE ACROSS
THE WEST. CURRENT THINKING IS THE FRONTAL BOUNDARY WILL BECOME MORE
ACTIVE AS IT ENTERS THE JAMES RIVER VALLEY LATER THIS
MORNING/AFTERNOON.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 335 AM CDT FRI AUG 29 2014
THE 07 UTC SURFACE OBSERVATIONS PLACE THE COLD FRONT IN FAR
NORTHWEST NORTH DAKOTA. THE COLD FRONT HAS BEEN SLOW MOVING EARLY
THIS MORNING AND IS EXPECTED TO CONTINUE A SLOW PROGRESSION
SOUTHEAST ACROSS THE AREA.
LATEST RUNS OF THE HRRR AND WRF HAVE HAD A DIFFICULT TIME
FORECASTING PRECIPITATION AHEAD AND BEHIND THE FRONT. AT THIS TIME
EXPECT ISOLATED TO SCATTERED SHOWERS THROUGH THE MORNING AND
AFTERNOON AS THE FRONT PASSES. FOR NOW LEFT THE POSSIBILITY OF
THUNDER IN THE FORECAST UP TO 12 UTC THIS MORNING THEN REMOVED
THUNDER CHANCES FROM 12 TO 18 UTC. AFTER 18 UTC THERE SHOULD BE
ENOUGH INSTABILITY FOR ISOLATED TO SCATTERED THUNDER ALONG THE
FRONT.
LATEST 07 UTC SURFACE OBSERVATIONS SHOW WIND HAS WENT MOSTLY CALM
OVER THE SOUTHEASTERN PORTION OF NORTH DAKOTA. WITH AMPLE LOW LEVEL
MOISTURE FOG HAS STARTED TO DEVELOP ACROSS THE SOUTH CENTRAL AND
SOUTHEAST. AT THIS TIME DO NOT BELIEVE ANY HEADLINE FOR FOG IS
NEEDED AND HAVE OPTED WITH A SPECIAL WEATHER STATEMENT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 335 AM CDT FRI AUG 29 2014
BEGINNING SATURDAY A WELL DEFINED SHORTWAVE TROUGH WILL BE MOVING
FROM THE PACIFIC NORTHWEST TO THE NORTHERN PLAINS. A SURFACE
TROUGH AND FRONTAL BOUNDARY WILL MOVE THROUGH WESTERN NORTH DAKOTA
BY SATURDAY NIGHT. MODELS HAVE BEEN CONSISTENT IN GENERATING A
LINE OF CONVECTION WITH THE FRONT. MODEL CAPES ARE INITIALLY
AROUND 2000 SATURDAY AFTERNOON WEST. AS THE SHORTWAVE AND SURFACE
TROUGH MOVE EAST AN H850 SOUTHERLY INFLOW OF 50 KTS WILL SUPPLY
ABUNDANT MOISTURE. THE PROGRESSIVE LINE OF STORMS LIKELY WILL
PRODUCE AN INCH OF QPF ACROSS CENTRAL NORTH DAKOTA....WITH LOCALLY
HIGHER AMOUNTS. CAPE AND SHEAR SUGGEST A PERIOD OF SEVERE STORMS
(LARGE HAIL/WINDS) ARE POSSIBLE WESTERN NORTH DAKOTA LATE SATURDAY
AFTERNOON/EVENING. KEPT THE HIGH POPS ACROSS WEST AND CENTRAL
SECTION SATURDAY EVENING AND TRAILED THEM DOWN AFTER MIDNIGHT.
FOLLOWING THIS A PERIOD (SUNDAY THROUGH TUESDAY) OF A RELATIVELY
COOL AND WEAKLY CYCLONIC FLOW ALOFT. THIS SHOULD SUPPORT WIDELY
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS. WEDNESDAY WILL BECOME A
TRANSITION DAY WITH DRY WEATHER AS THE NEXT SHORTWAVE IS MOVING
INTO THE NORTHWEST US WITH A DOWNSTREAM RIDGE OVER THE NORTHERN
PLAINS. THURSDAY WILL PICK UP A CHANCE FOR THUNDERSTORMS AGAIN
WITH THIS NEXT SHORTWAVE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 642 AM CDT FRI AUG 29 2014
A COLD FRONT HAS PASSED KISN...KMOT...AND KDIK THIS MORNING AND WILL
CONTINUE SOUTHEAST THROUGH THE MORNING. THIS WILL SHIFT WINDS AT
SITES KBIS AND KJMS NORTHWESTERLY. THIS WILL ALSO PROVIDE A CHANCE
OF SHOWERS AT KMOT...KDIK...KBIS...AND KJMS TODAY. ISOLATED
THUNDERSTORMS WILL ALSO BE POSSIBLE...HOWEVER HAVE LEFT TSRA OUT OF
THE TAFS FOR NOW. ANTICIPATE FOG TO DISSIPATE AT SITES KBIS AND KJMS
OVER THE NEXT FEW HOURS. OTHERWISE VFR CONDITIONS ARE EXPECTED
THROUGH THE 12Z TAF CYCLE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JJS
SHORT TERM...MM
LONG TERM...WAA
AVIATION...MM
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
657 AM CDT FRI AUG 29 2014
.UPDATE...
ISSUED AT 655 AM CDT FRI AUG 29 2014
NO SIG UPDATES NEEDED AT THIS TIME. BANDS OF LIGHT RAIN ARE MOVING
THROUGH THE BWP-FFM-PKD-BJI AREA IN THE DEFORMATION ZONE AT THE
AHEAD OF THE LOW PRESSURE SYSTEM NOW IN SOUTHWEST MN. MEANWHILE
A WINDSHIFT LINE IS APPARENT ON RADAR IMAGERY ALG A YWG-DVL-BIS
LINE SHOWING THE APPROACHING LOW PRESSURE SYSTEM NOW EDGING INTO
THE NORTHWEST CORNER OF THE FA. FOCUS FOR SHOWERS AND THUNDER
SHOULD SHIFT TO THIS SYSTEM FOR LATER IN THE DAY.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 415 AM CDT FRI AUG 29 2014
TODAY...AREAS OF LOW CLOUDS AND VERY LIGHT RAIN WILL SHIFT
EASTWARD FROM NORTHWEST MN THROUGH THE FORENOON... WITH SOME
PATCHY SUNSHINE POSSIBLE THROUGH THE MIDDAY PERIOD. A COLD FRONT
APPROACHING FROM SOUTHWEST MANITOBA WILL BRING INCREASING CLOUDS
INTO NORTHEAST ND DURING THE FORENOON AND PUSH THROUGH THE AREA
DURING THE AFTERNOON. EXPECT SCT SHOWERS AND AN ISOLATED
THUNDERSTORM OF TWO...WITH GUSTY NORTHWEST WINDS KICKING IN BEHIND
THE FRONT LATER TODAY. AS PER THREAT OF SEVERE STORMS TODAY...
WHILE DEEP LAYER SHEER IS WEAK TODAY AND DEEP MOISTURE ADVECTION
IS TIED UP BY THE MORE ORGANIZED SYSTEM IN THE CENTRAL PLAINS...
EXPECTED DAYTIME HEATING AND LOCALLY AVAILABLE MOISTURE LOOK TO
BE SUFFICIENT FOR 1000 TO 2000 J/KG OF CAPE BY MIDAFTERNOON... SO
AN ISOLATED SEVERE STORM IS POSSIBLE. RUC COMPUTED 2 KM LAYERED VGP
APPROACHES 0.2 FROM 18 INTO 21Z WITH LAYERED CAPE EXCEEDING 500
J/KG... ALMOST ENOUGH FOR A BRIEF SPINUP TO OCCUR. CERTAINLY
WORTH PAYING ATTENTION TOO... THUS LATEST SPC DAY1 OUTLOOK
CONTAINS A /SEE TEXT/ OVER OUR AREA.
TONIGHT AND SATURDAY...EXPECT GENERAL POSTFRONTAL DRYING AND
SEASONABLY COOL OVERNIGHT TEMPERATURES ESPECIALLY OVER THE
NORTHERN HALF OF THE FA. SOME LINGER SHOWERS ARE POSSIBLE INTO THE
LATE EVENING OVER NORTHCENTRAL MN LAKES. SATURDAY SHOULD BE DRY
AND SEASONABLY WARM ...WITH SOUTHERLY RETURN FLOW INCREASING
THROUGH THE AFTERNOON... AHEAD OF THE NEXT APPROACHING SYSTEM.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 415 AM CDT FRI AUG 29 2014
SATURDAY NIGHT AND SUNDAY...LOW PRESSURE DIGS INTO THE WRN DKTAS
LATE ON SATURDAY WITH DEEP CONVECTION EXPECTED TO CROSS INTO
CENTRAL ND THROUGH MIDNIGHT. BY SUNDAY MORNING MOST OF THE
ACTIVITY WILL SHIFT INTO ERN ND AND THE RED RIVER VALLEY...
OVERSPREADING NORTHWEST MINNESOTA THROUGH THE FORENOON. WITH
MODELS IN GENERAL AGREEMENT ON PLACING THE SFC TROF ALG THE RRV
AROUND 18Z... WILL EXPECT DEEP CONVECTION AND THE POSSIBILITY FOR
ISOLATED SEVERE STORMS AND LOCALLY HEAVY RAINS ALG AND EAST OF THE
RRV DURING THE AFTERNOON... CONSISTENT WITH CURRENT SPC/WPC DAY3
OUTLOOKS.
MONDAY THROUGH THURSDAY...FLOW BEGINS TO TRANSITION TO MORE
WESTERLY THEN SOUTHWESTERLY AS A LARGE TROUGH OVER THE NORTHERN
PLAINS MONDAY MOVES OFF TO THE EAST AND THE NEXT SYSTEM DIGS INTO
THE PAC NW. THINK THAT THE BEST CHANCES FOR PRECIP WILL BE LATE IN
THE PERIOD AS THE NEXT SFC LOW TRAVELS THROUGH SOUTH DAKOTA AND
PUTS OUR CWA IN THE PRIME DEFORMATION ZONE FOR PRECIPITATION.
HOWEVER...THERE WILL BE SOME LINGERING PRECIP ON THE BACKSIDE OF
THE DEPARTING LOW ON MONDAY AND EVEN DURING THE MIDDLE OF THE WEEK
SOME MODELS ARE BREAKING OUT SPITS OF PRECIP IN SOUTHWEST FLOW
ALOFT. WILL CONTINUE TO KEEP THE LOW POPS THAT ALLBLEND GIVES US
BUT WILL REFINE LATER. TEMPS WILL BE NEAR SEASONAL AVERAGES
THROUGHOUT THE PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 415 AM CDT FRI AUG 29 2014
EXPECT -SHRA TO CONTINUE ACROSS THE FAR SRN VALLEY AND INTO LAKES
COUNTY. OTHERWISE MOST AREAS WILL SEE MVFR/IFR CIGS AND PATCHY FOG
THROUGH THE MORNING. AREAS MVFR CIGS LIKELY THROUGH MIDDAY AHEAD
OF A SFC COLD FRONT FORECAST TO CROSS THE AREA. SCT SHOWERS AND
ISOLATED THUNDERSTORMS ARE EXPECTED AHEAD OF THE FRONT THROUGH THE
AFTERNOON.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...GUST
SHORT TERM...GUST
LONG TERM...GUST/JR
AVIATION...GUST
AREA FORECAST DISCUSSION
NWS BISMARCK ND
648 AM CDT FRI AUG 29 2014
.UPDATE...
ISSUED AT 642 AM CDT FRI AUG 29 2014
COLD FRONT MAKING ITS WAY INTO CENTRAL NORTH DAKOTA WITH VERY
LIMITED CONVECTION ALONG IT. POST FRONTAL SHOWERS CONTINUE ACROSS
THE WEST. CURRENT THINKING IS THE FRONTAL BOUNDARY WILL BECOME MORE
ACTIVE AS IT ENTERS THE JAMES RIVER VALLEY LATER THIS
MORNING/AFTERNOON.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 335 AM CDT FRI AUG 29 2014
THE 07 UTC SURFACE OBSERVATIONS PLACE THE COLD FRONT IN FAR
NORTHWEST NORTH DAKOTA. THE COLD FRONT HAS BEEN SLOW MOVING EARLY
THIS MORNING AND IS EXPECTED TO CONTINUE A SLOW PROGRESSION
SOUTHEAST ACROSS THE AREA.
LATEST RUNS OF THE HRRR AND WRF HAVE HAD A DIFFICULT TIME
FORECASTING PRECIPITATION AHEAD AND BEHIND THE FRONT. AT THIS TIME
EXPECT ISOLATED TO SCATTERED SHOWERS THROUGH THE MORNING AND
AFTERNOON AS THE FRONT PASSES. FOR NOW LEFT THE POSSIBILITY OF
THUNDER IN THE FORECAST UP TO 12 UTC THIS MORNING THEN REMOVED
THUNDER CHANCES FROM 12 TO 18 UTC. AFTER 18 UTC THERE SHOULD BE
ENOUGH INSTABILITY FOR ISOLATED TO SCATTERED THUNDER ALONG THE
FRONT.
LATEST 07 UTC SURFACE OBSERVATIONS SHOW WIND HAS WENT MOSTLY CALM
OVER THE SOUTHEASTERN PORTION OF NORTH DAKOTA. WITH AMPLE LOW LEVEL
MOISTURE FOG HAS STARTED TO DEVELOP ACROSS THE SOUTH CENTRAL AND
SOUTHEAST. AT THIS TIME DO NOT BELIEVE ANY HEADLINE FOR FOG IS
NEEDED AND HAVE OPTED WITH A SPECIAL WEATHER STATEMENT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 335 AM CDT FRI AUG 29 2014
BEGINNING SATURDAY A WELL DEFINED SHORTWAVE TROUGH WILL BE MOVING
FROM THE PACIFIC NORTHWEST TO THE NORTHERN PLAINS. A SURFACE
TROUGH AND FRONTAL BOUNDARY WILL MOVE THROUGH WESTERN NORTH DAKOTA
BY SATURDAY NIGHT. MODELS HAVE BEEN CONSISTENT IN GENERATING A
LINE OF CONVECTION WITH THE FRONT. MODEL CAPES ARE INITIALLY
AROUND 2000 SATURDAY AFTERNOON WEST. AS THE SHORTWAVE AND SURFACE
TROUGH MOVE EAST AN H850 SOUTHERLY INFLOW OF 50 KTS WILL SUPPLY
ABUNDANT MOISTURE. THE PROGRESSIVE LINE OF STORMS LIKELY WILL
PRODUCE AN INCH OF QPF ACROSS CENTRAL NORTH DAKOTA....WITH LOCALLY
HIGHER AMOUNTS. CAPE AND SHEAR SUGGEST A PERIOD OF SEVERE STORMS
(LARGE HAIL/WINDS) ARE POSSIBLE WESTERN NORTH DAKOTA LATE SATURDAY
AFTERNOON/EVENING. KEPT THE HIGH POPS ACROSS WEST AND CENTRAL
SECTION SATURDAY EVENING AND TRAILED THEM DOWN AFTER MIDNIGHT.
FOLLOWING THIS A PERIOD (SUNDAY THROUGH TUESDAY) OF A RELATIVELY
COOL AND WEAKLY CYCLONIC FLOW ALOFT. THIS SHOULD SUPPORT WIDELY
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS. WEDNESDAY WILL BECOME A
TRANSITION DAY WITH DRY WEATHER AS THE NEXT SHORTWAVE IS MOVING
INTO THE NORTHWEST US WITH A DOWNSTREAM RIDGE OVER THE NORTHERN
PLAINS. THURSDAY WILL PICK UP A CHANCE FOR THUNDERSTORMS AGAIN
WITH THIS NEXT SHORTWAVE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 642 AM CDT FRI AUG 29 2014
A COLD FRONT HAS PASSED KISN...KMOT...AND KDIK THIS MORNING AND WILL
CONTINUE SOUTHEAST THROUGH THE MORNING. THIS WILL SHIFT WINDS AT
SITES KBIS AND KJMS NORTHWESTERLY. THIS WILL ALSO PROVIDE A CHANCE
OF SHOWERS AT KMOT...KDIK...KBIS...AND KJMS TODAY. ISOLATED
THUNDERSTORMS WILL ALSO BE POSSIBLE...HOWEVER HAVE LEFT TSRA OUT OF
THE TAFS FOR NOW. ANTICIPATE FOG TO DISSIPATE AT SITES KBIS AND KJMS
OVER THE NEXT FEW HOURS. OTHERWISE VFR CONDITIONS ARE EXPECTED
THROUGH THE 12Z TAF CYCLE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...WAA
SHORT TERM...MM
LONG TERM...WAA
AVIATION...MM
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
434 AM CDT FRI AUG 29 2014
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 415 AM CDT FRI AUG 29 2014
TODAY...AREAS OF LOW CLOUDS AND VERY LIGHT RAIN WILL SHIFT
EASTWARD FROM NORTHWEST MN THROUGH THE FORENOON... WITH SOME
PATCHY SUNSHINE POSSIBLE THROUGH THE MIDDAY PERIOD. A COLD FRONT
APPROACHING FROM SOUTHWEST MANITOBA WILL BRING INCREASING CLOUDS
INTO NORTHEAST ND DURING THE FORENOON AND PUSH THROUGH THE AREA
DURING THE AFTERNOON. EXPECT SCT SHOWERS AND AN ISOLATED
THUNDERSTORM OF TWO...WITH GUSTY NORTHWEST WINDS KICKING IN BEHIND
THE FRONT LATER TODAY. AS PER THREAT OF SEVERE STORMS TODAY...
WHILE DEEP LAYER SHEER IS WEAK TODAY AND DEEP MOISTURE ADVECTION
IS TIED UP BY THE MORE ORGANIZED SYSTEM IN THE CENTRAL PLAINS...
EXPECTED DAYTIME HEATING AND LOCALLY AVAILABLE MOISTURE LOOK TO
BE SUFFICIENT FOR 1000 TO 2000 J/KG OF CAPE BY MIDAFTERNOON... SO
AN ISOLATED SEVERE STORM IS POSSIBLE. RUC COMPUTED 2 KM LAYERED VGP
APPROACHES 0.2 FROM 18 INTO 21Z WITH LAYERED CAPE EXCEEDING 500
J/KG... ALMOST ENOUGH FOR A BRIEF SPINUP TO OCCUR. CERTAINLY
WORTH PAYING ATTENTION TOO... THUS LATEST SPC DAY1 OUTLOOK
CONTAINS A /SEE TEXT/ OVER OUR AREA.
TONIGHT AND SATURDAY...EXPECT GENERAL POSTFRONTAL DRYING AND
SEASONABLY COOL OVERNIGHT TEMPERATURES ESPECIALLY OVER THE
NORTHERN HALF OF THE FA. SOME LINGER SHOWERS ARE POSSIBLE INTO THE
LATE EVENING OVER NORTHCENTRAL MN LAKES. SATURDAY SHOULD BE DRY
AND SEASONABLY WARM ...WITH SOUTHERLY RETURN FLOW INCREASING
THROUGH THE AFTERNOON... AHEAD OF THE NEXT APPROACHING SYSTEM.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 415 AM CDT FRI AUG 29 2014
SATURDAY NIGHT AND SUNDAY...LOW PRESSURE DIGS INTO THE WRN DKTAS
LATE ON SATURDAY WITH DEEP CONVECTION EXPECTED TO CROSS INTO
CENTRAL ND THROUGH MIDNIGHT. BY SUNDAY MORNING MOST OF THE
ACTIVITY WILL SHIFT INTO ERN ND AND THE RED RIVER VALLEY...
OVERSPREADING NORTHWEST MINNESOTA THROUGH THE FORENOON. WITH
MODELS IN GENERAL AGREEMENT ON PLACING THE SFC TROF ALG THE RRV
AROUND 18Z... WILL EXPECT DEEP CONVECTION AND THE POSSIBILITY FOR
ISOLATED SEVERE STORMS AND LOCALLY HEAVY RAINS ALG AND EAST OF THE
RRV DURING THE AFTERNOON... CONSISTENT WITH CURRENT SPC/WPC DAY3
OUTLOOKS.
MONDAY THROUGH THURSDAY...FLOW BEGINS TO TRANSITION TO MORE
WESTERLY THEN SOUTHWESTERLY AS A LARGE TROUGH OVER THE NORTHERN
PLAINS MONDAY MOVES OFF TO THE EAST AND THE NEXT SYSTEM DIGS INTO
THE PAC NW. THINK THAT THE BEST CHANCES FOR PRECIP WILL BE LATE IN
THE PERIOD AS THE NEXT SFC LOW TRAVELS THROUGH SOUTH DAKOTA AND
PUTS OUR CWA IN THE PRIME DEFORMATION ZONE FOR PRECIPITATION.
HOWEVER...THERE WILL BE SOME LINGERING PRECIP ON THE BACKSIDE OF
THE DEPARTING LOW ON MONDAY AND EVEN DURING THE MIDDLE OF THE WEEK
SOME MODELS ARE BREAKING OUT SPITS OF PRECIP IN SOUTHWEST FLOW
ALOFT. WILL CONTINUE TO KEEP THE LOW POPS THAT ALLBLEND GIVES US
BUT WILL REFINE LATER. TEMPS WILL BE NEAR SEASONAL AVERAGES
THROUGHOUT THE PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 415 AM CDT FRI AUG 29 2014
EXPECT -SHRA TO CONTINUE ACROSS THE FAR SRN VALLEY AND INTO LAKES
COUNTY. OTHERWISE MOST AREAS WILL SEE MVFR/IFR CIGS AND PATCHY FOG
THROUGH TEH EARLY MORNING. CIGS WILL BECOME MAINLY VFR BY NOON
FRIDAY AHEAD OF A SFC COLD FRONT FORECAST TO CROSS THE AREA. SCT
SHOWERS AND ISOLATED THUNDERSTORMS ARE EXPECTED AHEAD OF THE FRONT
AND WILL INCLUDE SOME MENTION AND TIMING IN 12Z TAFS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
SHORT TERM...GUST
LONG TERM...GUST/JR
AVIATION...GUST
AREA FORECAST DISCUSSION
NWS BISMARCK ND
337 AM CDT FRI AUG 29 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 335 AM CDT FRI AUG 29 2014
THE 07 UTC SURFACE OBSERVATIONS PLACE THE COLD FRONT IN FAR
NORTHWEST NORTH DAKOTA. THE COLD FRONT HAS BEEN SLOW MOVING EARLY
THIS MORNING AND IS EXPECTED TO CONTINUE A SLOW PROGRESSION
SOUTHEAST ACROSS THE AREA.
LATEST RUNS OF THE HRRR AND WRF HAVE HAD A DIFFICULT TIME
FORECASTING PRECIPITATION AHEAD AND BEHIND THE FRONT. AT THIS TIME
EXPECT ISOLATED TO SCATTERED SHOWERS THROUGH THE MORNING AND
AFTERNOON AS THE FRONT PASSES. FOR NOW LEFT THE POSSIBILITY OF
THUNDER IN THE FORECAST UP TO 12 UTC THIS MORNING THEN REMOVED
THUNDER CHANCES FROM 12 TO 18 UTC. AFTER 18 UTC THERE SHOULD BE
ENOUGH INSTABILITY FOR ISOLATED TO SCATTERED THUNDER ALONG THE
FRONT.
LATEST 07 UTC SURFACE OBSERVATIONS SHOW WIND HAS WENT MOSTLY CALM
OVER THE SOUTHEASTERN PORTION OF NORTH DAKOTA. WITH AMPLE LOW LEVEL
MOISTURE FOG HAS STARTED TO DEVELOP ACROSS THE SOUTH CENTRAL AND
SOUTHEAST. AT THIS TIME DO NOT BELIEVE ANY HEADLINE FOR FOG IS
NEEDED AND HAVE OPTED WITH A SPECIAL WEATHER STATEMENT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 335 AM CDT FRI AUG 29 2014
BEGINNING SATURDAY A WELL DEFINED SHORTWAVE TROUGH WILL BE MOVING
FROM THE PACIFIC NORTHWEST TO THE NORTHERN PLAINS. A SURFACE
TROUGH AND FRONTAL BOUNDARY WILL MOVE THROUGH WESTERN NORTH DAKOTA
BY SATURDAY NIGHT. MODELS HAVE BEEN CONSISTENT IN GENERATING A
LINE OF CONVECTION WITH THE FRONT. MODEL CAPES ARE INITIALLY
AROUND 2000 SATURDAY AFTERNOON WEST. AS THE SHORTWAVE AND SURFACE
TROUGH MOVE EAST AN H850 SOUTHERLY INFLOW OF 50 KTS WILL SUPPLY
ABUNDANT MOISTURE. THE PROGRESSIVE LINE OF STORMS LIKELY WILL
PRODUCE AN INCH OF QPF ACROSS CENTRAL NORTH DAKOTA....WITH LOCALLY
HIGHER AMOUNTS. CAPE AND SHEAR SUGGEST A PERIOD OF SEVERE STORMS
(LARGE HAIL/WINDS) ARE POSSIBLE WESTERN NORTH DAKOTA LATE SATURDAY
AFTERNOON/EVENING. KEPT THE HIGH POPS ACROSS WEST AND CENTRAL
SECTION SATURDAY EVENING AND TRAILED THEM DOWN AFTER MIDNIGHT.
FOLLOWING THIS A PERIOD (SUNDAY THROUGH TUESDAY) OF A RELATIVELY
COOL AND WEAKLY CYCLONIC FLOW ALOFT. THIS SHOULD SUPPORT WIDELY
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS. WEDNESDAY WILL BECOME A
TRANSITION DAY WITH DRY WEATHER AS THE NEXT SHORTWAVE IS MOVING
INTO THE NORTHWEST US WITH A DOWNSTREAM RIDGE OVER THE NORTHERN
PLAINS. THURSDAY WILL PICK UP A CHANCE FOR THUNDERSTORMS AGAIN
WITH THIS NEXT SHORTWAVE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 335 AM CDT FRI AUG 29 2014
LIFR CONDITIONS AT KJMS AND PERIODICALLY AT KBIS THIS MORNING DUE
TO LOW CLOUDS AND FOG. AN ISOLATED THUNDERSTORM WILL BE POSSIBLE
AT SITE KISN EARLY THIS MORNING. THE MAIN THREAT WILL BE THE GUSTY
WINDS AS ANY PRECIPITATION SHOULD BE BRIEF. ELSEWHERE VFR
CONDITIONS ARE ANTICIPATED THROUGH THE 06 TAF PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...MM
LONG TERM...WAA
AVIATION...MM
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1144 PM CDT THU AUG 28 2014
.UPDATE...
ISSUED AT 1144 PM CDT THU AUG 28 2014
NO CHANGES PLANNED FOR THIS UPDATE.
UPDATE ISSUED AT 934 PM CDT THU AUG 28 2014
NO CHANGES PLANNED FOR THIS UPDATE.
UPDATE ISSUED AT 648 PM CDT THU AUG 28 2014
SATELLITE AND OBSERVATIONS SHOW CLOUD COVER PERSISTING OVER THE
AREA. HRRR AND RUC SHOWING A DELAY IN MOVING CLOUDS OUT OF THE DVL
BASIN SO ADJUSTED SKY GRIDS FOR THIS UPDATE. OTHERWISE...REST OF
FORECAST LOOKS GOOD.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 250 PM CDT THU AUG 28 2014
THE MAIN CHALLENGE WILL BE PRECIP CHANCES. MODELS ARE IN GOOD
OVERALL AGREEMENT WITH NO REAL PREFERENCE TODAY.
FOR THIS EVENING AND OVERNIGHT...EXPECT SOME SHOWERS AND PERHAPS A
RUMBLE OF THUNDER THIS EVENING IN ALL BUT THE FAR NW. THE BEST
CHANCE FOR SHOWERS OVERNIGHT WILL BE ALONG AND SOUTHEAST OF A
WAHPETON TO BAUDETTE LINE...WHERE DEEPER MOISTURE AND THE BEST
LIFT WILL BE. HAVE LINGERED POPS A BIT LONGER IN THE EAST THROUGH
MOST OF THE OVERNIGHT.
ON FRIDAY...A COOL FRONT WILL MOVE FROM NW TO SE. THERE SHOULD BE
A BAND OF SHOWERS AND STORMS ALONG AND BEHIND THE COLD
FRONT...WITH THE BEST CHANCE FOR MEASURABLE PRECIP IN THE NORTH
DURING THE MORNING...THEN IN THE SOUTH AND EAST DURING THE
AFTERNOON. THERE WILL BE MLCAPES OVER 1500 J/KG...SO A FEW
STRONGER STORMS ARE POSSIBLE DURING THE AFTERNOON. DEEP LAYERED
SHEAR WILL BE WEAK THOUGH...LESS THAN 20 KT...SO EXPECT PULSE TYPE
STORMS WITH PERHAPS SOME SMALL HAIL AND/OR BRIEF WIND GUSTS.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 250 PM CDT THU AUG 28 2014
FOR SATURDAY...IT SHOULD BE A DRY AND SEASONABLE DAY WITH HIGH
PRESSURE IN CONTROL.
FOR SAT NIGHT...A FAIRLY CLASSIC ELEVATED CONVECTIVE EVENT IS
POSSIBLE. A LLJ WILL INCREASE TO AROUND 50 KT INTO CENTRAL ND
AFTER 00Z SUN...ALONG WITH SHOWALTERS FALLING TO AROUND -4C SAT
NIGHT WITH 40KT OF EFFECTIVE SHEAR. THIS SHOULD LEAD TO AN
ELEVATED MCS MOVING FROM SW TO NE SAT NIGHT INTO SUNDAY MORNING. A
FEW STORMS COULD BE STRONG TO SEVERE WITH LARGE HAIL THE MAIN THREAT.
ON SUNDAY...THE SEVERE POTENTIAL WILL INCREASE DURING THE
AFTERNOON IN THE EAST AND SOUTH. THERE WILL BE AMPLE DEEP LAYERED
SHEAR AND INSTABILITY...AND THE POTENTIAL FOR FAIRLY WIDESPREAD
SHOWERS AND STORMS. SPC HAS OUTLOOKED THE EASTERN AREAS IN A DAY4
OUTLOOK...SO WE WILL HAVE TO MONITOR SUNDAY AFTERNOON FOR SEVERE
POTENTIAL DEPENDING ON THE EXACT LOCATION OF THE FRONT AND WHICH
AREAS RECEIVE INSOLATION DURING THE AFTERNOON.
FOR SUN NIGHT THROUGH THU...MODELS IN SIMILAR AGREEMENT EARLY IN
THE PERIOD WITH ZONAL UPPER AIR PATTERN AND A FRONT EXITING THE
REGION...WITH MOST ASSOCIATED CONVECTION EAST OF THE AREA BY SUN
NIGHT. MAIN DIFFERENCE IS DEPTH OF UPPER LOW OVER WRN
ONTARIO...WITH GFS SHOWING A DEEPER LOW THAN ECMWF. CONSALL
YIELDING CHANCE POPS BACK INTO THE VALLEY WITH THIS EXITING
SYSTEM. WITH 12Z MODEL RUNS FASTER THAN THIS AND NO COORD ISSUES
TO MY WEST...WILL LOWER POPS IN THE VALLEY TO 20S OR DRY. MON
THROUGH WED THEN GENERALLY DRY...WITH A FEW MINOR SHORT WAVES
YIELDING SOME LOW END POPS...AND SEASONAL TEMPS BEFORE NEXT SYSTEM
WORKS ITS WAY ACROSS SRN CANADA AND BRINGS A CHANCE FOR TSTMS
ACROSS THE NORTHERN PORTION OF THE CWA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1144 PM CDT THU AUG 28 2014
EXPECT -SHRA TO CONTINUE ACROSS THE SRN VALLEY AND INTO LAKES
COUNTY...WITH SPOTTY SHOWERS FARTHER NORTH. CIGS CONTINUE TO BE A
CHALLENGE BUT EXPECT CIGS TO LOWER INTO THE MVFR/IFR CATEGORY OVER
THE NEXT FEW HOURS...WITH AREAS OF PATCHY FOG. CIGS WILL BECOME
MAINLY VFR BY NOON FRIDAY AHEAD OF A SFC TROF FORECAST TO CROSS
THE AREA. SOME SHOWERS MAY POP UP AHEAD OF THE TROF BUT NOT ENOUGH
TO MENTION IN TAFS ATTM.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...HOPKINS
SHORT TERM...DK
LONG TERM...DK/SPEICHER
AVIATION...HOPKINS
AREA FORECAST DISCUSSION
NWS PORTLAND OR
954 AM PDT FRI AUG 29 2014
.SYNOPSIS...COOLER WESTERLY FLOW ALOFT IS INCREASING. THIS WILL BRING
CLOUDS AND COOLER AIR TO THE REGION...ALONG WITH A THREAT OF SHOWERS
FOR THIS WEEKEND. BEST CHANCES OF SHOWERS WILL BE ON SATURDAY AND
LATE SUNDAY. DRY AND MILD WEATHER RESUMES NEXT WEEK.
&&
.SHORT TERM...THROUGH SUNDAY...SURFACE FRONT CURRENTLY OFFSHORE
SHOULD STALL NEAR THE COAST THIS AFTERNOON...BUT THE UPPER
PORTION OF THE FRONT SHEARS OFF AND MOVES INLAND IN THE AFTERNOON SO
PRECIP CHANCES WILL MAINLY BE LIMITED TO N OREGON COAST AND SW
WASHINGTON COAST. RADAR CURRENTLY SHOWS SOME DRIZZLE OR LIGHT SHOWERS
MOVING TOWARD MOSTLY THE SW WASHINGTON COAST. 15Z HRRR INDICATES A
BAND OF LIGHT PRECIP MOVING ONTO THE COAST AND AFFECTING AS FAR SOUTH
AS TILLAMOOK COUNTY BETWEEN 19Z AND 23Z WHICH LOOKS TO BE THE BEST
CHANCE OF RAIN ANYWHERE IN THE FORECAST AREA TODAY. ANY PRECIP LATER
IN THE AFTERNOON AND EVENING WOULD LIKELY BE OROGRAPHICALLY ENHANCED
SO SLIGHT CHANCE REMAINS PARTICULARLY ON THE WINDWARD SIDE OF THE
COAST RANGE AND CASCADES...WITH MOISTURE FAVORING NORTH OREGON AND
SOUTH WASHINGTON. COOLER TEMPS TODAY WITH MORE CLOUD COVER AND
LOWERING 500 MB HEIGHTS AS THE UPPER TROUGH MOVES INTO THE REGION. A
SHORTWAVE TROUGH ARRIVES SAT AFTERNOON FOR A LITTLE MORE COOLING AND
A CHANCE OF SHOWERS...AGAIN MAINLY FOR THE COAST AND NORTHERN
INTERIOR ZONES. SOME UPPER LEVEL SUPPORT FOR SOME SHOWERS SUNDAY
ACROSS THE NORTHERN PART OF THE FORECAST AREA WITH CONTINUED COOLER
TEMPERATURES. BOWEN/26
.LONG TERM...MODELS ARE TRENDING TOWARD ANOTHER SYSTEM ARRIVING SUN
NIGHT AND MON.SURFACE FEATURES WEAKEN AS THE FRONT APPROACHES THE
COAST...BUT 850MB AND 700MB ONSHORE WINDS WILL ADVECT MOISTURE INTO
THE AREA. THIS COMBINED WITH TOTAL PRECIPITABLE WATER AROUND 1.25
INCH WILL INTRODUCE CHANCE POPS TO THE FAR NORTHERN ZONES. FURTHER
ON IN THE WEEK...THE UPPER RIDGE IS NOT BUILDING QUITE SO STRONGLY AS
BEFORE. THERE IS MORE ENERGY BEING PUT INTO CARVING OUT A TROUGH OVER
WESTERN CANADA THE EVENTUALLY SAGS INTO THE WESTERN U.S LATE IN THE
WEEK. THE AIR MASS WILL BE GENERALLY DRY SO THREAT OF SHOWERS REMAIN
LOW AT THIS POINT. HIGH TEMPERATURES LIKELY AT OR BELOW SEASONAL
NORMALS. THE TIMING AND LOCATION OF THESE SHOWERS ARE
STILL UNCERTAIN AS BOTH THE GFS AND ECMWF HAVE SLIGHTLY DIFFERENT
FORECAST. THESE WILL BE FURTHER REFINED WITH FUTURE UPDATES. /64/26
&&
.AVIATION...A WEAK FRONT WILL MOVE ACROSS SOUTHWEST WASHINGTON AND
NORTHWEST OREGON TODAY. THE FRONT WAS SEEN ON RADAR NEAR KHQM AT 930
AM WITH SOME CONVECTIVE SHOWERS OVER THE WATERS BEHIND THE FRONT.
CLOUDS HAVE DEVELOPED OVER MUCH OF WESTERN WASHINGTON THIS MORNING
WITH IFR AND LIFR ALONG THE NORTH COAST AND MOSTLY MVFR CONDITIONS
INLAND. EXPECT THE LIFR AND IFR CONDITIONS TO IMPROVE ALONG THE N
OREGON COAST AS THE FRONT APPROACHES AND LIFTS THE MARINE
INVERSION AFTER 18Z BECOMING MVFR. THERE WILL BE SOME DRIZZLE AND
LIGHT RAIN AS THE FRONT MOVES IN MIDDAY ALONG THE COAST.
INLAND...EXPECT MOSTLY MVFR CONDITIONS TO CONTINUE WITH A SLIGHT
CHANCE OF SOME LIGHT SHOWERS MAINLY FROM NORTH OF KAUO 19Z-22Z.
CLOUDS SHOULD BREAK OUT SOME AND LIFT AFT 20-21Z. MARINE LAYER
SHOULD CONTINUE TO DEEPEN OVERNIGHT TONIGHT. SCHNEIDER
KPDX AND APPROACHES...MVFR CIGS 015 TO 020 WILL CONTINUE THROUGH
20Z THEN LIFT SOME AND BECOME VFR AFTER 21-22Z. SCHNEIDER
&&
.MARINE...WEAK FRONT MOVING ACROSS THE WATERS TODAY WITH SOME
BRIEF LIGHT RAIN OVER THE WATERS NORTH OF CASCADE HEAD TODAY.
WINDS WILL REMAIN LIGHT SOUTHWESTERLY TODAY AND THEN SHIFT MORE
WESTERLY THIS EVENING. SEVERAL MORE WEAK FRONTS WILL PASS OVER THE
WATERS DURING THE WEEKEND. THE SEAS WILL COMPRISE OF A SMALL SW
SWELL AT AROUND 15 SECONDS AND A NORTHWEST FRESH SWELL FROM THE
GULF OF ALASKA AROUND 9 SECONDS. LIGHT WIND WAVES THE NEXT COUPLE
OF DAYS. A NW SWELL WILL BUILD SATURDAY NIGHT AND PEAK AROUND 7
FEET ON SUNDAY. HIGH PRESSURE WILL REBUILD MONDAY NIGHT AND
TUESDAY AND PERSISTENT NORTHERLY WINDS WILL RETURN TO THE WATERS.
SCHNEIDER
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...NONE.
&&
$$
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1000 PM EDT SAT AUG 30 2014
.SYNOPSIS...
A BERMUDA HIGH WILL DEVELOP AND LINGER INTO EARLY NEXT WEEK...
RESULTING IN TYPICAL SUMMERTIME HEAT AND SCATTERED AFTERNOON
THUNDERSTORMS EACH DAY.
&&
.NEAR TERM /THROUGH SUNDAY/...
EVENING UPDATE...MADE A NOTABLE CHANGE TO THE POP/WX/QPF GRIDS
OVERNIGHT. THE LAST FEW RUNS OF THE HRRR HAVE BEEN CONSISTENT AND
THE LATEST OP MODELS HAVE CAUGHT ONTO THE IDEA OF A LINE OF
-SHRA/TSRA ORGANIZING ACROSS THE SW/RN ZONES ARND 06Z THEN PUSHING
NE THRU 12Z BEFORE DISSIPATING. WONT ANTICIPATE STRONG WX WITH THIS
LINE AS IT MOVES UNDERNEATH STRONG RIDGING ALOFT AND INSTABILITY
WILL BE WEAK THROUGH A DEEP LAYER. OTHERWISE...A FG THREAT ACROSS
THE MTNS AND NC FTHILLS WILL BE CURTAILED WITH CONTINUED BKN/OVC
CLOUD COVER...YET PATCHY VSBYS IN THE ONE MILE OR LESS RANGE COULD
DEVELOP ACROSS THE NC MTN VALLEYS BEFORE DAYBREAK AS CLOUDS THIN
FROM THE SW AFT 09Z. MIN TEMPS WERE BUMPED UP A DEGREE OR TWO MOST
LOCALE BASED ON LATEST TRENDS AND ANTICIPATED SLOW COOLING RATES.
730 PM EDT UPDATE...CONV ACTIVITY HAS WANED ACROSS THE CWFA WITH THE
BEST LIFT REMAINING WEST OF THE ULVL RIDGE. THE HRRR AND NAM BOTH
HAVE A LINE OF -SHRA/TSRA DEVELOPING ARND 06Z OR SO ACROSS THE SW/RN
ZONES AND SWEEPING EAST THROUGH THE MORNING HRS. THIS HAS BEEN
PICKED UP BY THE LATEST 18Z GFS AS WELL. ANYWAY...THIS SCENARIO WILL
BE LOOKED AT MORE CLOSELY WITH THE EVENING UPDATE. FOR THE REMAINDER
OF THE EVENING...EXPECT ISOL CONV ACTIVITY ACROSS THE SW/RN NC MTNS
AND NE GA. THE MAIN THREAT WITH THESE STORMS WILL BE CTG LIGHTNING
WITH GUSTY OUTFLOWS PROBABLE AS WELL.
430 PM EDT UPDATE...LATEST COMP RADAR TRENDS SHOW CONV ACTIVITY
CONFINED ACROSS THE WRN ZONES OF THE CWFA. A 4 DEGREE F DROP OF SFC
TD/S IN THE PAST 3 HRS HAS KEPT SBCAPE VALUES LOW EAST OF THIS AREA
WHILE STRONG H5 RIDGING HAS NULLIFIED MLVL LAPSE RATES. THIS GENERAL
PATTERN WILL CHANGE LITTLE OVER THE NEXT FEW HRS AND THE BEST H85
MOIST TRANSPORT WILL REMAIN ACROSS WRN TN. THUS...ISOL TO SCT CONV
WILL CONTINUE WEST ALIGNED IN MECH LIFT AND SOME MEASURE OF ULVL
DPVA...WITH ISOL CELLS LIKELY DEVELOPING EAST ACROSS THE UPSTATE AND
NC FTHILLS. NOT EXPECTING ANYTHING STRONG NOR SEVERE THRU 800 PM
WITH ECHO TOPS ONLY REACHING 35-40 KFT ASSOCIATED WITH FAIRLY WEAK
UPDRAFTS.
AS OF 215 PM...LATEST CAM`S SHOWING A LITTLE MORE CONVECTIVE
RESPONSE THIS AFTERNOON SO HAVE NUDGED THE POPS HIGHER OVER THE
WESTERN UPSTATE AND THE MOUNTAINS. IT STILL LOOKS LIKE CONVECTIVE
COVERAGE WILL INCREASE AS THE AFTERNOON PROGRESSES OVER NE GA AND
THE SW MOUNTAINS...WITH COVERAGE THEN SPREADING NE INTO THE CENTRAL
MOUNTAINS/NORTHERN MOUNTAINS DURING THE EVENING HOURS AS A WEAK
SHORT WAVE MOVES THROUGH TN. CAN`T RULE OUT SOME SHOWERS/STORMS
AFFECTING THE ADJACENT FOOTHILLS/PIEDMONT DURING THE EVENING SO HAVE
BUMPED POPS UPWARD THERE PER LATEST CAMS. HAVE DISCOUNTED THE
SPURIOUS DEEP CONVECTION AND HEAVY QPF THAT THE NAM DEVELOPS IN THE
NC PIEDMONT OVERNIGHT. DO NOT SEE THE TRIGGERING MECHANISM FOR SUCH
A RESPONSE AND THERE IS NO SUPPORT FROM ANY OTHER MODEL.
IN REGARD TO THE BIG PICTURE...THE UPPER HIGH WILL BE GRADUALLY
SUPPRESSED TO THE SE AS A SERIES OF SHORT WAVES MOVE THROUGH THE TN
VALLEY INTO THE MID-ATLANTIC STATES. THE FIRST OF THESE SHORT WAVES
WILL MOVE BY THIS EVENING AND THEN ANOTHER ON SUNDAY. AS THE FIRST
WAVE MOVES BY TO THE WEST TONIGHT...SCT SHOWERS AND STORMS WILL
OCCUR MAINLY OVER THE MOUNTAINS...POSSIBLY CONTINUING INTO THE EARLY
MORNING HOURS OF SUNDAY. WITH MOIST PROFILES AND WEAK WIND FIELDS...
SEVERE STORMS ARE NOT EXPECTED. HOWEVER...SOME LOCALLY HEAVY IS
POSSIBLE.
ON SUNDAY...SCT SHOWERS AND STORMS ARE EXPECTED TO DEVELOP AGAIN AS
ANOTHER SHORT WAVE MOVES BY TO THE WEST COINCIDING WITH MAX HEATING.
THE MODELS HAVE BEEN TRENDING AWAY FROM SHOWING MUCH QPF RESPONSE
OUTSIDE THE MOUNTAINS ON SUNDAY. HENCE...HAVE DIALED BACK POPS TO THE
SLIGHT CHANCE/CHANCE RANGE OVER THE PIEDMONT. THE BEST COVERAGE
SHOULD BE ALONG THE SPINE OF THE MOUNTAINS WHERE NUMEROUS STORMS MAY
OCCUR.
USED OUR CONSALL BLEND TO POPULATE MOST FIELDS. TEMPS WILL CONTINUE
ABOVE CLIMO. MAX TEMPS ON SUNDAY WILL BE CLOSE TO TODAY`S
NUMBERS...THOUGH PERHAPS A COUPLE DEGREES LESS WARM IN THE MOUNTAINS
DUE TO MORE CONVECTIVE COVERAGE.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
AS OF 200 PM SATURDAY...FAIRLY STANDARD LATE SUMMER WEATHER IS
EXPECTED THROUGH THE SHORT TERM...AS SUBTROPICAL/BERMUDA HIGH
PRESSURE REMAINS AS THE DOMINANT SYNOPTIC SCALE FEATURE ACROSS THE
SOUTHEAST. THIS SHOULD GENERALLY SUPPORT WARM AND HUMID CONDITIONS
THROUGH THE PERIOD...WITH CHANCES FOR DIURNAL CONVECTION GENERALLY
EXPECTED TO BE NEAR TO SLIGHTLY ABOVE CLIMO (30 PERCENT MTNS/20
PERCENT ACROSS THE LOWER TERRAIN) MON AND TUE AFTERNOONS. CONVECTIVE
CHANCES MAY INCREASE SLIGHTLY ACROSS OUR WESTERN AREAS BY TUE
EVENING...AS DEEP LAYER MOISTURE INCREASES AHEAD OF A WEAK FRONTAL
ZONE. TEMPERATURES ARE EXPECTED TO REMAIN ABOUT A CATEGORY ABOVE
NORMAL THROUGH THE PERIOD.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 230 PM EDT SATURDAY...THE LATEST GLOBAL MODELS INDICATE THAT
H5 HEIGHTS WILL CONTINUE TO RISE OVER THE FORECAST AREA TUE NIGHT
INTO FRI AS A BROAD UPPER RIDGING AMPLIFIES ACROSS THE SOUTHEAST AND
GULF STATES. BY SAT...WEAK UPPER NWLY FLOW WILL SET UP AS THE CENTER
OF UPPER ANTICYCLONE RETROGRADES TOWARD THE WESTERN CONUS. AT THE
SURFACE...HIGH PRESSURE WILL WEAKEN AND SLIDE SOUTH OF THE AREA TUE
NIGHT AS A WEAK COLD FRONT APPROACHES FROM THE NW. THE FRONT WILL
PUSH THRU THE AREA ON WED AND BECOMES STATIONARY JUST TO OUR SOUTH
BY THU. A BERMUDA HIGH WILL THEN BUILD BACK IN FROM THE SE BY FRI
AND REMAIN IN PLACE THRU DAY 7. AS FOR OUR SENSIBLE WEATHER...HAVE
MENTIONED 30/40 POPS WED/THU DUE TO INCREASING MOISTURE AND BUOYANCY
ALONG AND AHEAD OF THE FRONT. FRI/SAT...DIURNAL BUOYANCY AND
MOISTURE UNDER THE INFLUENCE OF BERMUDA HIGH WILL BE SUPPORTIVE OF
SCATTERED AFTERNOON SHOWERS AND THUNDERSTORMS ON EACH
DAY...MAINTAINING POPS IN THE 30/40 RANGE. TEMPERATURES WILL STAY
AROUND 2-5 DEGREES ABOVE NORMAL WED/THU BEFORE COOLING TO NEAR
NORMAL BY FRI.
&&
.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
AT KCLT...VFR CONDS THROUGH MOST OF THE OVERNIGHT TIL ARND 10Z OR SO
WHEN MVFR VSBY MAY FORM THROUGH 14Z. ACTUAL CLOUD COVER WILL BE THE
LIMITING FACTOR. THERE IS A LOW CHANCE OF A LINE OF -SHRA OR TSRA
REACHING THE TERMINAL VICINITY ARND 10Z...BUT IT WILL PROBABLY
DISIPATE TO THE WEST. ANOTHER LOW CHANCE FOR CONV SUN LATE AFTERNOON
AND WILL MENTION WITH A PROB30 AT 20Z.
ELSEWHERE...GOOD CLOUD COVER ACROSS THE MTNS WILL LIMIT RADIATIONAL
COOLING AT KAVL AND KHKY...BUT MVFR/IFR VSBY IS NOT OUT OF THE
QUESTION AFT 08Z....WILL GO MVFR FOR THIS ISSUANCE. A LINE OF
-SHRA/TSRA COULD WORK ACROSS THE MTNS AND INTO THE UPSTATE AFT 08Z
AS WELL AND THIS WILL BE COVERED WITH VCSH AT ALL TERMINALS...EXCEPT
VCTS AT KAVL THROUGH 12Z/13Z. CONV ACTIVITY WILL AFFECT MAINLY KAVL
AND KHKY SUN AFTERNOON...BUT ALL SITES HAVE HIGH ENOUGH CHANCES TO
WARRANT A LATE PERIOD PROB30 TSRA.
OUTLOOK...GENERALLY VFR CONDITIONS ARE EXPECTED THROUGH EARLY NEXT
WEEK WITH THE EXCEPTION FOR RESTRICTIONS IN THE EARLY MORNING DUE TO
LOW CLOUDS AND FOG...PRIMARILY IN THE MOUNTAIN VALLEYS. DIURNAL
CONVECTION IS EXPECTED EACH AFTERNOON WITH THE MOST COVERAGE OVER
THE MOUNTAINS.
CONFIDENCE TABLE...
02-08Z 08-14Z 14-20Z 20-02Z
KCLT HIGH 100% HIGH 83% HIGH 100% HIGH 100%
KGSP HIGH 100% MED 73% HIGH 96% HIGH 100%
KAVL HIGH 100% HIGH 81% HIGH 100% HIGH 100%
KHKY HIGH 100% HIGH 87% HIGH 96% HIGH 100%
KGMU HIGH 99% HIGH 84% HIGH 96% HIGH 100%
KAND HIGH 100% HIGH 82% HIGH 98% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JOH
NEAR TERM...LG/SBK
SHORT TERM...JDL
LONG TERM...JOH
AVIATION...SBK
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
750 PM EDT SAT AUG 30 2014
.SYNOPSIS...
A BERMUDA HIGH WILL DEVELOP AND LINGER INTO EARLY NEXT WEEK...
RESULTING IN TYPICAL SUMMERTIME HEAT AND SCATTERED AFTERNOON
THUNDERSTORMS EACH DAY.
&&
.NEAR TERM /THROUGH SUNDAY/...
730 PM EDT UPDATE...CONV ACTIVITY HAS WANED ACROSS THE CWFA WITH THE
BEST LIFT REMAINING WEST OF THE ULVL RIDGE. THE HRRR AND NAM BOTH
HAVE A LINE OF -SHRA/TSRA DEVELOPING ARND 06Z OR SO ACROSS THE SW/RN
ZONES AND SWEEPING EAST THROUGH THE MORNING HRS. THIS HAS BEEN
PICKED UP BY THE LATEST 18Z GFS AS WELL. ANYWAY...THIS SCENARIO WILL
BE LOOKED AT MORE CLOSELY WITH THE EVENING UPDATE. FOR THE REMAINDER
OF THE EVENING...EXPECT ISOL CONV ACTIVITY ACROSS THE SW/RN NC MTNS
AND NE GA. THE MAIN THREAT WITH THESE STORMS WILL BE CTG LIGHTNING
WITH GUSTY OUTFLOWS PROBABLE AS WELL.
430 PM EDT UPDATE...LATEST COMP RADAR TRENDS SHOW CONV ACTIVITY
CONFINED ACROSS THE WRN ZONES OF THE CWFA. A 4 DEGREE F DROP OF SFC
TD/S IN THE PAST 3 HRS HAS KEPT SBCAPE VALUES LOW EAST OF THIS AREA
WHILE STRONG H5 RIDGING HAS NULLIFIED MLVL LAPSE RATES. THIS GENERAL
PATTERN WILL CHANGE LITTLE OVER THE NEXT FEW HRS AND THE BEST H85
MOIST TRANSPORT WILL REMAIN ACROSS WRN TN. THUS...ISOL TO SCT CONV
WILL CONTINUE WEST ALIGNED IN MECH LIFT AND SOME MEASURE OF ULVL
DPVA...WITH ISOL CELLS LIKELY DEVELOPING EAST ACROSS THE UPSTATE AND
NC FTHILLS. NOT EXPECTING ANYTHING STRONG NOR SEVERE THRU 800 PM
WITH ECHO TOPS ONLY REACHING 35-40 KFT ASSOCIATED WITH FAIRLY WEAK
UPDRAFTS.
AS OF 215 PM...LATEST CAM`S SHOWING A LITTLE MORE CONVECTIVE
RESPONSE THIS AFTERNOON SO HAVE NUDGED THE POPS HIGHER OVER THE
WESTERN UPSTATE AND THE MOUNTAINS. IT STILL LOOKS LIKE CONVECTIVE
COVERAGE WILL INCREASE AS THE AFTERNOON PROGRESSES OVER NE GA AND
THE SW MOUNTAINS...WITH COVERAGE THEN SPREADING NE INTO THE CENTRAL
MOUNTAINS/NORTHERN MOUNTAINS DURING THE EVENING HOURS AS A WEAK
SHORT WAVE MOVES THROUGH TN. CAN`T RULE OUT SOME SHOWERS/STORMS
AFFECTING THE ADJACENT FOOTHILLS/PIEDMONT DURING THE EVENING SO HAVE
BUMPED POPS UPWARD THERE PER LATEST CAMS. HAVE DISCOUNTED THE
SPURIOUS DEEP CONVECTION AND HEAVY QPF THAT THE NAM DEVELOPS IN THE
NC PIEDMONT OVERNIGHT. DO NOT SEE THE TRIGGERING MECHANISM FOR SUCH
A RESPONSE AND THERE IS NO SUPPORT FROM ANY OTHER MODEL.
IN REGARD TO THE BIG PICTURE...THE UPPER HIGH WILL BE GRADUALLY
SUPPRESSED TO THE SE AS A SERIES OF SHORT WAVES MOVE THROUGH THE TN
VALLEY INTO THE MID-ATLANTIC STATES. THE FIRST OF THESE SHORT WAVES
WILL MOVE BY THIS EVENING AND THEN ANOTHER ON SUNDAY. AS THE FIRST
WAVE MOVES BY TO THE WEST TONIGHT...SCT SHOWERS AND STORMS WILL
OCCUR MAINLY OVER THE MOUNTAINS...POSSIBLY CONTINUING INTO THE EARLY
MORNING HOURS OF SUNDAY. WITH MOIST PROFILES AND WEAK WIND FIELDS...
SEVERE STORMS ARE NOT EXPECTED. HOWEVER...SOME LOCALLY HEAVY IS
POSSIBLE.
ON SUNDAY...SCT SHOWERS AND STORMS ARE EXPECTED TO DEVELOP AGAIN AS
ANOTHER SHORT WAVE MOVES BY TO THE WEST COINCIDING WITH MAX HEATING.
THE MODELS HAVE BEEN TRENDING AWAY FROM SHOWING MUCH QPF RESPONSE
OUTSIDE THE MOUNTAINS ON SUNDAY. HENCE...HAVE DIALED BACK POPS TO THE
SLIGHT CHANCE/CHANCE RANGE OVER THE PIEDMONT. THE BEST COVERAGE
SHOULD BE ALONG THE SPINE OF THE MOUNTAINS WHERE NUMEROUS STORMS MAY
OCCUR.
USED OUR CONSALL BLEND TO POPULATE MOST FIELDS. TEMPS WILL CONTINUE
ABOVE CLIMO. MAX TEMPS ON SUNDAY WILL BE CLOSE TO TODAY`S
NUMBERS...THOUGH PERHAPS A COUPLE DEGREES LESS WARM IN THE MOUNTAINS
DUE TO MORE CONVECTIVE COVERAGE.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
AS OF 200 PM SATURDAY...FAIRLY STANDARD LATE SUMMER WEATHER IS
EXPECTED THROUGH THE SHORT TERM...AS SUBTROPICAL/BERMUDA HIGH
PRESSURE REMAINS AS THE DOMINANT SYNOPTIC SCALE FEATURE ACROSS THE
SOUTHEAST. THIS SHOULD GENERALLY SUPPORT WARM AND HUMID CONDITIONS
THROUGH THE PERIOD...WITH CHANCES FOR DIURNAL CONVECTION GENERALLY
EXPECTED TO BE NEAR TO SLIGHTLY ABOVE CLIMO (30 PERCENT MTNS/20
PERCENT ACROSS THE LOWER TERRAIN) MON AND TUE AFTERNOONS. CONVECTIVE
CHANCES MAY INCREASE SLIGHTLY ACROSS OUR WESTERN AREAS BY TUE
EVENING...AS DEEP LAYER MOISTURE INCREASES AHEAD OF A WEAK FRONTAL
ZONE. TEMPERATURES ARE EXPECTED TO REMAIN ABOUT A CATEGORY ABOVE
NORMAL THROUGH THE PERIOD.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 230 PM EDT SATURDAY...THE LATEST GLOBAL MODELS INDICATE THAT
H5 HEIGHTS WILL CONTINUE TO RISE OVER THE FORECAST AREA TUE NIGHT
INTO FRI AS A BROAD UPPER RIDGING AMPLIFIES ACROSS THE SOUTHEAST AND
GULF STATES. BY SAT...WEAK UPPER NWLY FLOW WILL SET UP AS THE CENTER
OF UPPER ANTICYCLONE RETROGRADES TOWARD THE WESTERN CONUS. AT THE
SURFACE...HIGH PRESSURE WILL WEAKEN AND SLIDE SOUTH OF THE AREA TUE
NIGHT AS A WEAK COLD FRONT APPROACHES FROM THE NW. THE FRONT WILL
PUSH THRU THE AREA ON WED AND BECOMES STATIONARY JUST TO OUR SOUTH
BY THU. A BERMUDA HIGH WILL THEN BUILD BACK IN FROM THE SE BY FRI
AND REMAIN IN PLACE THRU DAY 7. AS FOR OUR SENSIBLE WEATHER...HAVE
MENTIONED 30/40 POPS WED/THU DUE TO INCREASING MOISTURE AND BUOYANCY
ALONG AND AHEAD OF THE FRONT. FRI/SAT...DIURNAL BUOYANCY AND
MOISTURE UNDER THE INFLUENCE OF BERMUDA HIGH WILL BE SUPPORTIVE OF
SCATTERED AFTERNOON SHOWERS AND THUNDERSTORMS ON EACH
DAY...MAINTAINING POPS IN THE 30/40 RANGE. TEMPERATURES WILL STAY
AROUND 2-5 DEGREES ABOVE NORMAL WED/THU BEFORE COOLING TO NEAR
NORMAL BY FRI.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
AT KCLT...VFR CONDS THROUGH MOST OF THE OVERNIGHT TIL ARND 10Z OR SO
WHEN MVFR VSBY MAY FORM THROUGH 14Z. ACTUAL CLOUD COVER WILL BE THE
LIMITING FACTOR. THERE IS A LOW CHANCE OF A LINE OF -SHRA OR TSRA
REACHING THE TERMINAL VICINITY ARND 10Z...BUT IT WILL PROBABLY
DISIPATE TO THE WEST. ANOTHER LOW CHANCE FOR CONV SUN LATE AFTERNOON
AND WILL MENTION WITH A PROB30 AT 20Z.
ELSEWHERE...GOOD CLOUD COVER ACROSS THE MTNS WILL LIMIT RADIATIONAL
COOLING AT KAVL AND KHKY...BUT MVFR/IFR VSBY IS NOT OUT OF THE
QUESTION AFT 08Z....WILL GO MVFR FOR THIS ISSUANCE. A LINE OF
-SHRA/TSRA COULD WORK ACROSS THE MTNS AND INTO THE UPSTATE AFT 08Z
AS WELL AND THIS WILL BE COVERED WITH VCSH AT ALL TERMINALS...EXCEPT
VCTS AT KAVL THROUGH 12Z/13Z. CONV ACTIVITY WILL AFFECT MAINLY KAVL
AND KHKY SUN AFTERNOON...BUT ALL SITES HAVE HIGH ENOUGH CHANCES TO
WARRANT A LATE PERIOD PROB30 TSRA.
OUTLOOK...GENERALLY VFR CONDITIONS ARE EXPECTED THROUGH EARLY NEXT
WEEK WITH THE EXCEPTION FOR RESTRICTIONS IN THE EARLY MORNING DUE TO
LOW CLOUDS AND FOG...PRIMARILY IN THE MOUNTAIN VALLEYS. DIURNAL
CONVECTION IS EXPECTED EACH AFTERNOON WITH THE MOST COVERAGE OVER
THE MOUNTAINS.
CONFIDENCE TABLE...
00-06Z 06-12Z 12-18Z 18-24Z
KCLT HIGH 100% HIGH 86% HIGH 90% HIGH 100%
KGSP HIGH 100% MED 78% HIGH 85% HIGH 100%
KAVL HIGH 100% HIGH 87% HIGH 94% HIGH 100%
KHKY HIGH 100% HIGH 86% HIGH 92% HIGH 100%
KGMU HIGH 100% HIGH 89% HIGH 88% HIGH 100%
KAND HIGH 100% HIGH 88% HIGH 95% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JOH
NEAR TERM...LG/SBK
SHORT TERM...JDL
LONG TERM...JOH
AVIATION...SBK
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1053 AM EDT FRI AUG 29 2014
.SYNOPSIS...
A COLD FRONT WILL LINGER OVER NORTH CAROLINA TODAY BEFORE
DISSIPATING TONIGHT. A BERMUDA HIGH WILL SET UP FOR THE WEEKEND AND
EARLY NEXT WEEK...BRINGING TYPICAL SUMMERTIME HEAT AND
HUMIDITY...WITH SCATTERED AFTERNOON SHOWERS AND THUNDERSTORMS EACH
DAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
1015 AM UPDATE...STRATUS DECK HAS EXPANDED INTO THE NW NC PIEDMONT
WITHIN WEDGELIKE AIR MASS NORTH OF PESKY BACK DOOR FRONT. THE DECK/S
PROGRESS HAS SLOWED EVIDENTLY DUE TO MIXING ALONG THE EDGES AS
TEMPERATURES RISE. NONETHELESS IT STANDS A GOOD CHANCE OF LASTING
INTO MIDDAY DUE TO UPGLIDE ATOP THE COOLER LAYER. BIGGEST CHANGE TO
THE FCST AT THIS UPDATE WAS TO REFLECT THE MCLDY SKIES IN THIS AREA.
AS FOR POPS...MOST OF THE GUIDANCE DEVELOPS DEEP CONVECTION ONLY
OVER THE RIDGETOPS TODAY...DESPITE THE ELEVATED INSTABILITY SEEN
ABOVE THE STRATUS LAYER. THIS EVIDENCED BY RAP SOUNDINGS AS WELL AS
THE TOWERS SEEN EMBEDDED IN THE DECK ON SATELLITE OVER THE TRIAD
REGION. MAINTAINED SIMILAR POP TRENDS TO THOSE FROM EARLIER PACKAGE
BUT FOCUSED THEM MORE OVER THE NW NC PIEDMONT THIS MRNG FOR THE
LATTER REASON. NEWEST GUID ALSO ALLOWS SOME ELEVATED ACTIVITY TO
FIRE OVERNIGHT TONIGHT...BUT WITH THE WEDGE BEGINNING TO BREAK DOWN
BY THEN I WOULD LIKE TO SEE MORE OF A CONSENSUS BEFORE ADDING ANY
POPS FOR IT.
PREVIOUS DISCUSSION...
AS OF 330 AM EDT FRIDAY...UPPER LEVEL RIDGE CENTERED OVER THE
SOUTHEAST WILL CONTINUE TO DOMINATE THE PATTERN THROUGH THE NEAR
TERM FORECAST PERIOD. MEANWHILE...DEEPENING SHORT WAVE TROF ACROSS
THE CENTRAL/SOUTHERN PLAINS CONTINUES TO PROMOTE PRESSURE FALLS AT
THE SURFACE LEADING TO STRONG MOISTURE ADVECTION ACROSS THE LOWER
MISSISSIPPI RIVER VALLEY. ALSO AT THE SURFACE...QUASI STATIONARY
BACK DOOR FRONT REMAINS DRAPED IN AN EAST/WEST ORIENTATION ACROSS
NORTH CAROLINA...WEST INTO TENNESSEE. A 1020MB SURFACE HIGH
ACROSS THE NORTHEAST CONTINUES SLIDE EAST AND WEDGE DOWN THE LEE
SIDE OF THE CENTRAL AND SOUTHERN APPS.
LATEST SATELLITE DIFFERENCE PRODUCT IMAGERY AND SURFACE OBS ANALYSIS
INDICATE AREA OF STRATUS DEVELOPMENT TIED TO A ZONE OF SURFACE
CONVERGENCE ALONG THE ABOVE MENTIONED BACK DOOR FRONT AND INTRUDING
SURFACE RIDGE. GUIDANCE HAS HANDLED THIS SITUATION FAIRLY WELL
AND ALSO INDICATES FURTHER EXPANSION OF LOW STRATUS INTO THE
CENTRAL/SOUTHERN PIEDMONT REGION THROUGH LATE MORNING.
MEANWHILE...CALMING WINDS AND VERY MOIST DECOUPLING PBL ACROSS THE
HIGH TERRAIN WILL LEAD TO DEVELOPMENT OF PATCHY FOG THIS MORNING
WITH VISIBILITIES DROPPING TO LESS THAN 2 MILES...MAINLY IN AND
AROUND THE MOUNTAIN VALLEYS. EXPECTING ABOVE MENTIONED HIGH
PRESSURE BOUNDARY AND OLD BACK DOOR FRONTAL BOUNDARY TO BE THE
PRIMARY FOCUS OF CONCERN THROUGH THE NEAR TERM PERIOD. LOCATIONS
SOUTH OF THIS AXIS SUCH AS THE UPSTATE OF SOUTH CAROLINA AND
NORTHEAST GEORGIA WILL EXPERIENCE A FAIRLY NICE FRIDAY WITH MOSTLY
SUNNY SKIES AND DRY CONDITIONS PREVAILING AMONGST WEAK/INCREASING
SOUTHERLY FLOW AND UPPER LEVEL SUBSIDENCE. AS FOR LOCATIONS TO THE
NORTH...SURFACE CONVERGENCE...BETTER MOISTURE PROFILES...AND WEAKER
CAPPING WILL WARRANT MENTION OF ISOLATED/SCATTERED SHOWERS AND
THUNDERSTORMS. FORECAST SOUNDINGS DO INDICATE MODEST INSTABILITY
ACROSS THE SOUTHERN TIER OF WESTERN NORTH CAROLINA WERE BETTER
DIFFERENTIAL HEATING IS EXPECTED. HOWEVER THIS THREAT SEEMS TO BE
TIED TO A RATHER SMALL AREA WERE ENOUGH INSTABILITY WILL EXIST
ADJACENT TO THE SURFACE CONVERGENCE AXIS PROVIDING NEEDED FORCING.
ALL SAID...THE HWO WILL MENTION LOW END THREAT FOR DIURNAL HEATING
AIDED ISOLATED THUNDERSTORMS ALONG THE I40 CORRIDOR WITH DAMAGING
WINDS AND FREQUENT LIGHTNING BEING THE PRIMARY THREATS. CONVECTION
WILL TAPER INTO THE EARLY EVENING HOURS AS HEATING SUBSIDES WITH ALL
POPS BEING REMOVED BY MIDNIGHT. TEMPERATURES ON FRIDAY WILL REACH
NORMAL LEVELS ACROSS MUCH OF THE UPSTATE AND NORTHEAST GEORGIA WITH
HIGHS BEING SLIGHTLY COOLER ACROSS WESTERN NORTH CAROLINA DUE TO SKY
COVER AND POSSIBLE CONVECTION.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 340 AM FRIDAY...UPPER ANTICYCLONE OVER THE SERN CONUS SLIDES
TO COAST SAT...THEN REMAINS THERE THRU THE PERIOD. THE ASSOCIATED
RIDGING REMAINS IN PLACE...BUT SLOWLY WEAKENS OR IS SUPPRESSED AS
NRN AND SRN STREAM SHORT WAVES MOVE EAST OVER AND INTO THE RIDGE. AT
THE SFC...SLY FLOW DEVELOPS AS A WEAK COLD FRONT MOVES TOWARD THE
AREA. THE FRONT WASHES OUT SUN...BUT SLY FLOW REMAINS AS A LEE TROF
DEVELOPS. WITH THE MOISTURE INCREASE...INSTABILITY DEVELOPS ACROSS
THE MTNS AND UPPER SAV RIVER VALLEY...LEADING TO SCT DIURNAL
CONVECTION. COULD SEE ISOLATED CONVECTION ACROSS THE FOOTHILLS AND
WRN UPSTATE IN THE TRANSITION ZONE BETWEEN AN UNSTABLE ATMOS AND A
CAPPED ATMOS OVER THE NC PIEDMONT AND ERN UPSTATE. TEMPS WILL BE
NEAR TO A LITTLE ABOVE NORMAL. MODERATE INSTABILITY DEVELOPS ACROSS
THE AREA SUN AS LOW LEVEL MOISTURE CONTINUES TO INCREASE. THE
WEAKENING BOUNDARY AND LEE TROF SHUD PROVIDE LOW LEVEL CONVERGENCE
WHILE THE SHORT WAVES AND UPPER DIVERGENCE FROM THE RIGHT ENTRANCE
REGION OF A JET STREAK PROVIDE SYNOPTIC SCALE FORCING. THE RESULT
WILL BE NUMEROUS COVERAGE OF DIURNAL CONVECTION ACROSS THE MTNS AND
SOLID SCT COVERAGE ALONG AND NORTH OF THE I-85 CORRIDOR...TAPERING
OFF SLIGHTLY TO THE SOUTH. PW VALUES INCREASE TO AROUND 2 INCHES
SUNDAY AND COULD LEAD TO STORMS WITH HEAVY RAINFALL...AND POSSIBLY
ISOLATED EXCESSIVE RAINFALL. HIGHS SUN WILL BE NEAR NORMAL WITH LOWS
SUN NITE A LITTLE ABOVE NORMAL.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 355 AM FRIDAY...THE UPPER ANTICYCLONE REMAINS SUPPRESSED OVER
THE SERN CONUS AT THE START OF THE PERIOD...THEN SLOWLY RETROGRADES
ACROSS THE GULF COAST STATES INTO THE MID SOUTH WITH RIDGING
BUILDING OVER THE MS RIVER VALLEY. NEARLY ZONAL FLOW ON TOP OF THE
ANTICYCLONE WILL BRING WEAK SHORT WAVES NEAR OR ACROSS THE AREA.
WEAK SLY LOW LEVEL FLOW AND A SFC LEE TROF REMAIN ACROSS THE AREA
THRU THE PERIOD. A COLD FRONT DOES DROP SOUTH TOWARD THE AREA WED...
BUT DISSIPATES BEFORE REACHING THE AREA. THIS WILL LEAD TO GENERALLY
SCT DIURNAL CONVECTION EACH DAY...WITH A RELATIVELY LULL ON TUE OF
LOW END SCT MTNS AND FOOTHILLS AND ISOLATED ELSEWHERE. HIGHS WILL BE
NEAR TO A LITTLE ABOVE NORMAL EACH DAY...WITH LOWS A LITTLE ABOVE
NORMAL THRU THE PERIOD.
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
AT KCLT...STATIONARY FRONTAL BOUNDARY WILL REMAIN IN THE AREA
THROUGH THE DAY BEFORE LIFTING NORTH OF THE AREA FRIDAY NIGHT INTO
SATURDAY MORNING. MVFR STRATUS DECK WILL LINGER IN THE AREA AS HIGH
PRESSURE WEDGES SOUTHWARD AND INTERACTS WITH ABOVE MENTIONED
BOUNDARY...BUT MIXING IS EXPECTED TO PREVENT IT FROM FORMING A CIG
AT THE FIELD EXCEPT MAYBE BRIEFLY. NORTHEAST WINDS WILL INCREASE
INTO THE 5-7KTS RANGE THROUGH MORNING BEFORE VEERING SOUTHERLY AS
THE BOUNDARY PUSHES NORTH LATE IN THE DAY OR EARLY EVENING. SOME LOW
END GUSTS ARE LIKELY AT TIMES THIS MORNING. CARRIED LIGHT
SOUTHEASTERLY WINDS UNDER LOW VFR CU FROM 00Z THROUGH THE REMAINDER
OF THE PERIOD.
ELSEWHERE...EXPECTING VFR CONDITIONS TO PREVAIL THROUGH THE PERIOD
AT ALL SITES WITH THE POSSIBLE EXCEPTION OF FOG RESTRICITONS AT KAVL
SATURDAY MORNING. INITIALIZED ALL TAFS VFR WITH AN INTRODUCTION OF
MVFR LEVEL STRATUS AROUND 14Z AT KHKY AS MOISTURE CONDENSES ALONG
CONVERGENCE AXIS BETWEEN INTRUDING HIGH PRESSURE AND OLD STATIONARY
FRONT. VFR WILL RETURN TO ALL SITES BY MIDDAY WITH SKIES SCT OUT AND
WINDS SHIFTING SOUTHERLY AT THE SC SITES AND KAVL AS THE ABOVE
MENTIONED FRONT MIGRATES NORTH WHILE KHKY REMAINS NORTHERLY THROUGH
THE END OF THE PERIOD.
OUTLOOK...MOISTURE RETURN THROUGH THE WEEKEND WILL LEAD TO
INCREASING CHANCES FOR ISOLATED/SCATTERED DIURNAL SHRA AND TSRA WITH
THE GREATEST PROBABILITIES RESIDING ALONG THE HIGH TERRAIN. IN
ADDITION...MORNING FOG/STRATUS WILL BE POSSIBLE WITH THE MOUNTAINS
ONCE AGAIN HAVING THE GREATEST CHANCES AT RESTRICTIONS.
CONFIDENCE TABLE...
15-21Z 21-03Z 03-09Z 09-15Z
KCLT MED 78% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 100% MED 65% MED 65%
KHKY MED 61% HIGH 100% MED 70% MED 62%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...WIMBERLEY
NEAR TERM...CDG/WIMBERLEY
SHORT TERM...RWH
LONG TERM...RWH
AVIATION...CDG/WIMBERLEY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1032 AM EDT FRI AUG 29 2014
.SYNOPSIS...
A COLD FRONT WILL DROP DOWN INTO NORTH CAROLINA FROM THE NORTH THIS
MORNING...LINGERING OVER THE REGION BRIEFLY BEFORE DISSIPATING
TONIGHT. A BERMUDA HIGH WILL SET UP FOR THE WEEKEND AND EARLY NEXT
WEEK...BRINGING TYPICAL SUMMERTIME HEAT AND HUMIDITY...WITH
SCATTERED AFTERNOON SHOWERS AND THUNDERSTORMS EACH DAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
1015 AM UPDATE...STRATUS DECK HAS EXPANDED INTO THE NW NC PIEDMONT
WITHIN WEDGELIKE AIR MASS NORTH OF PESKY BACK DOOR FRONT. THE DECK/S
PROGRESS HAS SLOWED EVIDENTLY DUE TO MIXING ALONG THE EDGES AS
TEMPERATURES RISE. NONETHELESS IT STANDS A GOOD CHANCE OF LASTING
INTO MIDDAY DUE TO UPGLIDE ATOP THE COOLER LAYER. BIGGEST CHANGE TO
THE FCST AT THIS UPDATE WAS TO REFLECT THE MCLDY SKIES IN THIS AREA.
AS FOR POPS...MOST OF THE GUIDANCE DEVELOPS DEEP CONVECTION ONLY
OVER THE RIDGETOPS TODAY...DESPITE THE ELEVATED INSTABILITY SEEN
ABOVE THE STRATUS LAYER. THIS EVIDENCED BY RAP SOUNDINGS AS WELL AS
THE TOWERS SEEN EMBEDDED IN THE DECK ON SATELLITE OVER THE TRIAD
REGION. MAINTAINED SIMILAR POP TRENDS TO THOSE FROM EARLIER PACKAGE
BUT FOCUSED THEM MORE OVER THE NW NC PIEDMONT THIS MRNG FOR THE
LATTER REASON. NEWEST GUID ALSO ALLOWS SOME ELEVATED ACTIVITY TO
FIRE OVERNIGHT TONIGHT...BUT WITH THE WEDGE BEGINNING TO BREAK DOWN
BY THEN I WOULD LIKE TO SEE MORE OF A CONSENSUS BEFORE ADDING ANY
POPS FOR IT.
PREVIOUS DISCUSSION...
AS OF 330 AM EDT FRIDAY...UPPER LEVEL RIDGE CENTERED OVER THE
SOUTHEAST WILL CONTINUE TO DOMINATE THE PATTERN THROUGH THE NEAR
TERM FORECAST PERIOD. MEANWHILE...DEEPENING SHORT WAVE TROF ACROSS
THE CENTRAL/SOUTHERN PLAINS CONTINUES TO PROMOTE PRESSURE FALLS AT
THE SURFACE LEADING TO STRONG MOISTURE ADVECTION ACROSS THE LOWER
MISSISSIPPI RIVER VALLEY. ALSO AT THE SURFACE...QUASI STATIONARY
BACK DOOR FRONT REMAINS DRAPED IN AN EAST/WEST ORIENTATION ACROSS
NORTH CAROLINA...WEST INTO TENNESSEE. A 1020MB SURFACE HIGH
ACROSS THE NORTHEAST CONTINUES SLIDE EAST AND WEDGE DOWN THE LEE
SIDE OF THE CENTRAL AND SOUTHERN APPS.
LATEST SATELLITE DIFFERENCE PRODUCT IMAGERY AND SURFACE OBS ANALYSIS
INDICATE AREA OF STRATUS DEVELOPMENT TIED TO A ZONE OF SURFACE
CONVERGENCE ALONG THE ABOVE MENTIONED BACK DOOR FRONT AND INTRUDING
SURFACE RIDGE. GUIDANCE HAS HANDLED THIS SITUATION FAIRLY WELL
AND ALSO INDICATES FURTHER EXPANSION OF LOW STRATUS INTO THE
CENTRAL/SOUTHERN PIEDMONT REGION THROUGH LATE MORNING.
MEANWHILE...CALMING WINDS AND VERY MOIST DECOUPLING PBL ACROSS THE
HIGH TERRAIN WILL LEAD TO DEVELOPMENT OF PATCHY FOG THIS MORNING
WITH VISIBILITIES DROPPING TO LESS THAN 2 MILES...MAINLY IN AND
AROUND THE MOUNTAIN VALLEYS. EXPECTING ABOVE MENTIONED HIGH
PRESSURE BOUNDARY AND OLD BACK DOOR FRONTAL BOUNDARY TO BE THE
PRIMARY FOCUS OF CONCERN THROUGH THE NEAR TERM PERIOD. LOCATIONS
SOUTH OF THIS AXIS SUCH AS THE UPSTATE OF SOUTH CAROLINA AND
NORTHEAST GEORGIA WILL EXPERIENCE A FAIRLY NICE FRIDAY WITH MOSTLY
SUNNY SKIES AND DRY CONDITIONS PREVAILING AMONGST WEAK/INCREASING
SOUTHERLY FLOW AND UPPER LEVEL SUBSIDENCE. AS FOR LOCATIONS TO THE
NORTH...SURFACE CONVERGENCE...BETTER MOISTURE PROFILES...AND WEAKER
CAPPING WILL WARRANT MENTION OF ISOLATED/SCATTERED SHOWERS AND
THUNDERSTORMS. FORECAST SOUNDINGS DO INDICATE MODEST INSTABILITY
ACROSS THE SOUTHERN TIER OF WESTERN NORTH CAROLINA WERE BETTER
DIFFERENTIAL HEATING IS EXPECTED. HOWEVER THIS THREAT SEEMS TO BE
TIED TO A RATHER SMALL AREA WERE ENOUGH INSTABILITY WILL EXIST
ADJACENT TO THE SURFACE CONVERGENCE AXIS PROVIDING NEEDED FORCING.
ALL SAID...THE HWO WILL MENTION LOW END THREAT FOR DIURNAL HEATING
AIDED ISOLATED THUNDERSTORMS ALONG THE I40 CORRIDOR WITH DAMAGING
WINDS AND FREQUENT LIGHTNING BEING THE PRIMARY THREATS. CONVECTION
WILL TAPER INTO THE EARLY EVENING HOURS AS HEATING SUBSIDES WITH ALL
POPS BEING REMOVED BY MIDNIGHT. TEMPERATURES ON FRIDAY WILL REACH
NORMAL LEVELS ACROSS MUCH OF THE UPSTATE AND NORTHEAST GEORGIA WITH
HIGHS BEING SLIGHTLY COOLER ACROSS WESTERN NORTH CAROLINA DUE TO SKY
COVER AND POSSIBLE CONVECTION.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 340 AM FRIDAY...UPPER ANTICYCLONE OVER THE SERN CONUS SLIDES
TO COAST SAT...THEN REMAINS THERE THRU THE PERIOD. THE ASSOCIATED
RIDGING REMAINS IN PLACE...BUT SLOWLY WEAKENS OR IS SUPPRESSED AS
NRN AND SRN STREAM SHORT WAVES MOVE EAST OVER AND INTO THE RIDGE. AT
THE SFC...SLY FLOW DEVELOPS AS A WEAK COLD FRONT MOVES TOWARD THE
AREA. THE FRONT WASHES OUT SUN...BUT SLY FLOW REMAINS AS A LEE TROF
DEVELOPS. WITH THE MOISTURE INCREASE...INSTABILITY DEVELOPS ACROSS
THE MTNS AND UPPER SAV RIVER VALLEY...LEADING TO SCT DIURNAL
CONVECTION. COULD SEE ISOLATED CONVECTION ACROSS THE FOOTHILLS AND
WRN UPSTATE IN THE TRANSITION ZONE BETWEEN AN UNSTABLE ATMOS AND A
CAPPED ATMOS OVER THE NC PIEDMONT AND ERN UPSTATE. TEMPS WILL BE
NEAR TO A LITTLE ABOVE NORMAL. MODERATE INSTABILITY DEVELOPS ACROSS
THE AREA SUN AS LOW LEVEL MOISTURE CONTINUES TO INCREASE. THE
WEAKENING BOUNDARY AND LEE TROF SHUD PROVIDE LOW LEVEL CONVERGENCE
WHILE THE SHORT WAVES AND UPPER DIVERGENCE FROM THE RIGHT ENTRANCE
REGION OF A JET STREAK PROVIDE SYNOPTIC SCALE FORCING. THE RESULT
WILL BE NUMEROUS COVERAGE OF DIURNAL CONVECTION ACROSS THE MTNS AND
SOLID SCT COVERAGE ALONG AND NORTH OF THE I-85 CORRIDOR...TAPERING
OFF SLIGHTLY TO THE SOUTH. PW VALUES INCREASE TO AROUND 2 INCHES
SUNDAY AND COULD LEAD TO STORMS WITH HEAVY RAINFALL...AND POSSIBLY
ISOLATED EXCESSIVE RAINFALL. HIGHS SUN WILL BE NEAR NORMAL WITH LOWS
SUN NITE A LITTLE ABOVE NORMAL.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 355 AM FRIDAY...THE UPPER ANTICYCLONE REMAINS SUPPRESSED OVER
THE SERN CONUS AT THE START OF THE PERIOD...THEN SLOWLY RETROGRADES
ACROSS THE GULF COAST STATES INTO THE MID SOUTH WITH RIDGING
BUILDING OVER THE MS RIVER VALLEY. NEARLY ZONAL FLOW ON TOP OF THE
ANTICYCLONE WILL BRING WEAK SHORT WAVES NEAR OR ACROSS THE AREA.
WEAK SLY LOW LEVEL FLOW AND A SFC LEE TROF REMAIN ACROSS THE AREA
THRU THE PERIOD. A COLD FRONT DOES DROP SOUTH TOWARD THE AREA WED...
BUT DISSIPATES BEFORE REACHING THE AREA. THIS WILL LEAD TO GENERALLY
SCT DIURNAL CONVECTION EACH DAY...WITH A RELATIVELY LULL ON TUE OF
LOW END SCT MTNS AND FOOTHILLS AND ISOLATED ELSEWHERE. HIGHS WILL BE
NEAR TO A LITTLE ABOVE NORMAL EACH DAY...WITH LOWS A LITTLE ABOVE
NORMAL THRU THE PERIOD.
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
AT KCLT...VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD.
STATIONARY FRONTAL BOUNDARY WILL REMAIN IN THE AREA THROUGH THE DAY
BEFORE LIFTING NORTH OF THE AREA FRIDAY NIGHT INTO SATURDAY MORNING.
STILL EXPECTING SKY COVER TO INCREASE ACROSS THE NC PIEDMONT LATER
THIS MORNING AS HIGH PRESSURE WEDGES SOUTHWARD AND INTERACTS WITH
ABOVE MENTIONED BOUNDARY. THUS...LOW STRATUS CURRENTLY TO THE NORTH
IS EXPECTED TO EXPAND SOUTHWARD AND LOWER OVER THE AIRFIELD AROUND
THE 14Z TIMEFRAME WITH NO CIG RESTRICIONS FORECAST AT THIS TIME AS
TAF ONLY HIGHLIGHTS SCT025. THIS LOW SCT STRATUS WILL LINGER
THROUGH MUCH OF THE MORNING...EVENTUALLY LIFTING BY APPROX 18Z.
NORTHEAST WINDS WILL INCREASE INTO THE 5-7KTS RANGE THROUGH MORNING
BEFORE VEERING SOUTHERLY AS THE BOUNDARY PUSHES NORTH LATE IN THE
DAY OR EARLY EVENING. CARRIED LIGHT SOUTHEASTERLY WINDS UNDER LOW
VFR CU FROM 00Z THROUGH THE REMAINDER OF THE PERIOD.
ELSEWHERE...EXPECTING VFR CONDITIONS TO PREVAIL THROUGH THE PERIOD
AT ALL SITES WITH THE POSSIBLE EXCEPTION OF FOG RESTRICITONS AT
KAVL SATURDAY MORNING. INITIALIZED ALL TAFS VFR WITH AN
INTRODUCTION OF MVFR LEVEL STRATUS AROUND 14Z AT KHKY AS MOISTURE
CONDENSES ALONG CONVERGENCE AXIS BETWEEN INTRUDING HIGH PRESSURE AND
OLD STATIONARY FRONT. VFR WILL RETURN TO ALL SITES BY MIDDAY WITH
SKIES SCT OUT AND WINDS SHIFTING SOUTHERLY AT THE SC SITES AND KAVL
AS THE ABOVE MENTIONED FRONT MIGRATES NORTH WHILE KHKY REMAINS
NORTHERLY THROUGH THE END OF THE PERIOD.
OUTLOOK...MOISTURE RETURN THROUGH THE WEEKEND WILL LEAD TO
INCREASING CHANCES FOR ISOLATED/SCATTERED DIURNAL SHRA AND TSRA WITH
THE GREATEST PROBABILITIES RESIDING ALONG THE HIGH TERRAIN. IN
ADDITION...MORNING FOG/STRATUS WILL BE POSSIBLE WITH THE MOUNTAINS
ONCE AGAIN HAVING THE GREATEST CHANCES AT RESTRICTIONS.
CONFIDENCE TABLE...
14-20Z 20-02Z 02-08Z 08-14Z
KCLT MED 70% HIGH 100% HIGH 100% HIGH 90%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 100% MED 73% MED 74%
KHKY MED 66% HIGH 92% MED 66% MED 75%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...RWH
NEAR TERM...CDG/WIMBERLEY
SHORT TERM...RWH
LONG TERM...RWH
AVIATION...CDG
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1116 PM CDT THU AUG 28 2014
.UPDATE...ADDED AVIATION SECTION FOR 06Z TAF`S.
&&
.AVIATION...BNA/CKV/CSV...EXCELLENT RADIATIONAL COOLING IS
UNDERWAY THIS EVENING WITH FOG ALREADY DEVELOPING AT CSV AND
EXPECTED TO FORM AT CKV LATER TONIGHT. LOOK FOR FOG TO SCATTER OUT
SHORTLY AFTER 12Z FRIDAY MORNING, WITH VFR WX THE REST OF THE WAY.
&&
.PREV DISCUSSION... /ISSUED 934 PM CDT THU AUG 28 2014/
UPDATE...FOR EVENING DISCUSSION.
DISCUSSION...
CONVECTION HAS COME TO AN END FOR NOW. A COUPLE OF OUTFLOW
BOUNDARIES ARE STILL FLOATING AROUND MIDDLE TENNESSEE WITH PLENTY
OF INSTABILITY TO BE TAPPED INTO. WILL KEEP A SLIGHT CHANCE POP
FOR AREAS BASICALLY ALONG AND NORTH OF INTERSTATE 40 UNTIL
MIDNIGHT OR SO TO ACCOUNT FOR THIS. SOME PATCHY LATE-NIGHT/EARLY
MORNING FOG WILL BE LIKELY FOR THOSE WHO SAW RAINFALL THIS
EVENING.
THE FRONTAL BOUNDARY THAT HAS BEEN RESPONSIBLE FOR THIS EVENING`S
CONVECTION WILL PULL OFF TO THE NORTH LATER TONIGHT AND THIS
SHOULD TAKE POPS OUT OF THE FORECAST FOR FRIDAY.
UPDATES ON THE WAY.
UNGER
AVIATION...00Z TAF DISCUSSION.
BNA/CKV/CSV...ISOLATED CELLS CONTINUE ACROSS MAINLY NORTHERN
MIDDLE TENNESSEE LATE THIS AFTERNOON. HRRR SHOWS EXISTING ACTIVITY
DISSIPATING DURING THE EVENING AS WE LOSE DAYTIME HEATING. SURFACE
RIDGE HAS SLIPPED TO OUR EAST WITH WEAK RETURN FLOW NOW UNDERWAY.
EXPECT FULL RADIATIONAL COOLING OVERNIGHT, WITH LIGHT FOG POSSIBLE
AT CKV AND CSV. VERY LITTLE CHANCE OF CONVECTION ON FRIDAY, SO WE
SHOULD BE VFR THE NEXT 24 HRS OUTSIDE OF EARLY MORNING FOG.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
ROSE
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
628 AM CDT FRI AUG 29 2014
.DISCUSSION...UPDATED FOR 12Z AVIATION.
&&
.AVIATION...EXPECT SH/TSRA POTENTIAL THROUGH MUCH OF THE DAY FOR
EASTERN TAF SITES. LATE THIS EVENING WE SHOULD HAVE A BREAK IN THE
ACTIVITY...BUT HAVE PROB 30 GROUP FOR CRP AND VCT AGAIN SATURDAY
MORNING FOR ADDITIONAL CONVECTION DEVELOPING. FOR THE MOST PART
SHOULD HAVE VFR CIGS THROUGH THE PERIOD...BUT WILL SEE TEMPO MVFR
NEAR THUNDERSTORMS.
&&
.PREV DISCUSSION... /ISSUED 424 AM CDT FRI AUG 29 2014/
SHORT TERM (TODAY THROUGH SATURDAY)...WEAK SURFACE LOW AND MID
LEVEL WEAKNESS CURRENTLY LOCATED NEAR THE COAST OF DEEP SOUTH
TEXAS WITH ABUNDANT MOISTURE ASSOCIATED WITH IT. WHAT HAPPENS
TODAY WILL HAVE EVERYTHING TO DO WITH THE MOVEMENT OF THIS LOW
THROUGH THE DAY. A NEARLY STATIONARY POSITION WAS THE GENERAL
CONSENSUS EARLY TONIGHT...BUT LATEST MESO MODELS ARE STARTING TO
SUGGEST THE LOW PULLING SOUTH AND EAST THIS MORNING. THIS WOULD
LEAD TO SLIGHTLY LOWER MOISTURE...AND LESS LIFT OVER FORECAST
AREA...HOLDING THE MUCH NEEDED RAIN MOSTLY OFFSHORE DURING THE
DAY. WHILE THE 06Z HRRR HAS ALSO GONE THIS DIRECTION...WILL STILL
HOLD OUT HOPE THAT ENOUGH MOISTURE IS IN PLACE TO VERIFY CHANCE TO
LIKELY POPS ACROSS EASTERN AREAS. THERE WAS SOME CONCERN FOR HEAVY
RAINFALL...BUT THINK THAT SHOULD REMAIN SOUTH OF FORECAST AREA.
HAVE LOWER POPS WEST...BUT THINK SOME AFTERNOON CONVECTION SHOULD
MAKE ITS WAY WEST. HAVE GONE A BIT COOLER WITH MAX
TEMPS...ESPECIALLY EAST WHERE DEEPER MOISTURE/CLOUD COVER IS
EXPECTED. STILL HAVE EVERYONE IN THE 90S...BUT LOWER
90S...ESPECIALLY SOUTHEAST ZONES.
TOMORROW NIGHT LOOKS QUITE SIMILAR TO TONIGHT...EXCEPT FEEL BETTER
CHANCE FOR POPS WILL BE A BIT FURTHER EAST AS UPPER ENERGY BECOMES
ELONGATED JUST OFFSHORE THE MIDDLE TEXAS COAST. HAVE SLIGHTLY LOWER
POPS THAN TODAY...AND TEMPS BACK TOWARD NORMAL FOR SATURDAY. A
LIGHT TO MODERATE SOUTHEAST WIND CAN BE EXPECTED BOTH FRIDAY AND
SATURDAY.
LONG TERM (SATURDAY NIGHT THROUGH THURSDAY)...UPPER LEVEL WEAKNESS
WILL RESIDE OVER SOUTH TEXAS TO BEGIN THE LONG TERM. MOISTURE WILL
REMAIN SUFFICIENT ESPECIALLY OVER THE COASTAL PLAINS SATURDAY NIGHT
AND SUNDAY...RESULTING IN ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS. BY MONDAY...FLATTENED UPPER LEVEL RIDGE WILL SETTLE
OVER SOUTH TEXAS ALONG WITH SLIGHTLY DRIER AIR. THIS SHOULD KEEP
CHANCES FOR SHOWERS AND STORMS TOO LOW TO MENTION IN THE FORECAST. A
TROPICAL WAVE CURRENTLY LOCATED IN THE EASTERN CARIBBEAN WILL
CONTINUE TO MOVE WESTWARD THROUGH THE WEEKEND. BY EARLY NEXT WEEK...
THIS SYSTEM WILL EMERGE INTO THE BAY OF CAMPECHE AND SOUTHERN GULF
OF MEXICO. WHILE DEEPEST MOISTURE SHOULD REMAIN TO THE SOUTH OF THE
REGION...PW VALUES WILL RETURN TO AROUND 2 INCHES OVER THE COASTAL
LOCATIONS/MARINE ZONES BY WEDNESDAY. ISOLATED TO SCATTERED SHOWERS
AND THUNDERSTORMS WILL BE POSSIBLE AGAIN BY TUESDAY...AND CONTINUING
THROUGH THURSDAY. WARMEST DAYS OF THE EXTENDED WILL BE SUNDAY AND
MONDAY...WITH TEMPS BEING SET BACK A FEW DEGREES BY MID WEEK AS THE
DEEPER MOISTURE RETURNS.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 90 78 92 78 96 / 60 40 40 20 30
VICTORIA 93 76 93 76 98 / 50 30 40 20 30
LAREDO 98 79 98 79 103 / 30 30 20 20 10
ALICE 91 77 93 76 99 / 50 30 30 20 20
ROCKPORT 88 79 90 79 93 / 60 40 40 20 30
COTULLA 97 76 97 76 101 / 30 20 20 20 10
KINGSVILLE 91 78 92 78 98 / 60 40 30 20 20
NAVY CORPUS 87 80 89 80 92 / 60 50 40 20 30
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...RIP CURRENT RISK UNTIL 6 PM CDT THIS EVENING FOR THE FOLLOWING
ZONES: ARANSAS...CALHOUN...KLEBERG...NUECES.
GM...NONE.
&&
$$
PZ/83...AVIATION
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
424 AM CDT FRI AUG 29 2014
.SHORT TERM (TODAY THROUGH SATURDAY)...WEAK SURFACE LOW AND MID
LEVEL WEAKNESS CURRENTLY LOCATED NEAR THE COAST OF DEEP SOUTH
TEXAS WITH ABUNDANT MOISTURE ASSOCIATED WITH IT. WHAT HAPPENS
TODAY WILL HAVE EVERYTHING TO DO WITH THE MOVEMENT OF THIS LOW
THROUGH THE DAY. A NEARLY STATIONARY POSITION WAS THE GENERAL
CONSENSUS EARLY TONIGHT...BUT LATEST MESO MODELS ARE STARTING TO
SUGGEST THE LOW PULLING SOUTH AND EAST THIS MORNING. THIS WOULD
LEAD TO SLIGHTLY LOWER MOISTURE...AND LESS LIFT OVER FORECAST
AREA...HOLDING THE MUCH NEEDED RAIN MOSTLY OFFSHORE DURING THE
DAY. WHILE THE 06Z HRRR HAS ALSO GONE THIS DIRECTION...WILL STILL
HOLD OUT HOPE THAT ENOUGH MOISTURE IS IN PLACE TO VERIFY CHANCE TO
LIKELY POPS ACROSS EASTERN AREAS. THERE WAS SOME CONCERN FOR HEAVY
RAINFALL...BUT THINK THAT SHOULD REMAIN SOUTH OF FORECAST AREA.
HAVE LOWER POPS WEST...BUT THINK SOME AFTERNOON CONVECTION SHOULD
MAKE ITS WAY WEST. HAVE GONE A BIT COOLER WITH MAX
TEMPS...ESPECIALLY EAST WHERE DEEPER MOISTURE/CLOUD COVER IS
EXPECTED. STILL HAVE EVERYONE IN THE 90S...BUT LOWER
90S...ESPECIALLY SOUTHEAST ZONES.
TOMORROW NIGHT LOOKS QUITE SIMILAR TO TONIGHT...EXCEPT FEEL BETTER
CHANCE FOR POPS WILL BE A BIT FURTHER EAST AS UPPER ENERGY BECOMES
ELONGATED JUST OFFSHORE THE MIDDLE TEXAS COAST. HAVE SLIGHTLY LOWER
POPS THAN TODAY...AND TEMPS BACK TOWARD NORMAL FOR SATURDAY. A
LIGHT TO MODERATE SOUTHEAST WIND CAN BE EXPECTED BOTH FRIDAY AND
SATURDAY.
&&
.LONG TERM (SATURDAY NIGHT THROUGH THURSDAY)...UPPER LEVEL WEAKNESS
WILL RESIDE OVER SOUTH TEXAS TO BEGIN THE LONG TERM. MOISTURE WILL
REMAIN SUFFICIENT ESPECIALLY OVER THE COASTAL PLAINS SATURDAY NIGHT
AND SUNDAY...RESULTING IN ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS. BY MONDAY...FLATTENED UPPER LEVEL RIDGE WILL SETTLE
OVER SOUTH TEXAS ALONG WITH SLIGHTLY DRIER AIR. THIS SHOULD KEEP
CHANCES FOR SHOWERS AND STORMS TOO LOW TO MENTION IN THE FORECAST. A
TROPICAL WAVE CURRENTLY LOCATED IN THE EASTERN CARIBBEAN WILL
CONTINUE TO MOVE WESTWARD THROUGH THE WEEKEND. BY EARLY NEXT WEEK...
THIS SYSTEM WILL EMERGE INTO THE BAY OF CAMPECHE AND SOUTHERN GULF
OF MEXICO. WHILE DEEPEST MOISTURE SHOULD REMAIN TO THE SOUTH OF THE
REGION...PW VALUES WILL RETURN TO AROUND 2 INCHES OVER THE COASTAL
LOCATIONS/MARINE ZONES BY WEDNESDAY. ISOLATED TO SCATTERED SHOWERS
AND THUNDERSTORMS WILL BE POSSIBLE AGAIN BY TUESDAY...AND CONTINUING
THROUGH THURSDAY. WARMEST DAYS OF THE EXTENDED WILL BE SUNDAY AND
MONDAY...WITH TEMPS BEING SET BACK A FEW DEGREES BY MID WEEK AS THE
DEEPER MOISTURE RETURNS.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 90 78 92 78 96 / 60 40 40 20 30
VICTORIA 93 76 93 76 98 / 50 30 40 20 30
LAREDO 98 79 98 79 103 / 30 30 20 20 10
ALICE 91 77 93 76 99 / 50 30 30 20 20
ROCKPORT 88 79 90 79 93 / 60 40 40 20 30
COTULLA 97 76 97 76 101 / 30 20 20 20 10
KINGSVILLE 91 78 92 78 98 / 60 40 30 20 20
NAVY CORPUS 87 80 89 80 92 / 60 50 40 20 30
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...RIP CURRENT RISK THROUGH THIS AFTERNOON FOR THE FOLLOWING ZONES:
ARANSAS...CALHOUN...KLEBERG...NUECES.
GM...NONE.
&&
$$
PZ/83...SHORT TERM
TB/78...LONG TERM
AREA FORECAST DISCUSSION...UPDATED
NWS SAN ANGELO TX
1201 AM CDT FRI AUG 29 2014
.AVIATION...
/06Z TAFS/
Numerous showers and thunderstorms are moving east across the
northern half of West Central Texas. Initially Carrying a TSRA
mention at KABI, with VCSH at KSJT. The showers and storms will
move east and gradually dissipate overnight, with considerable
high cloudiness remaining over the northern half of the area.
Patchy low cloud development is possible early Friday morning in
some of our southern/southeastern counties, and including a
scattered layer at our southern TAF sites. Scattered showers and
thunderstorms could develop by Friday afternoon, but with
uncertainty on coverage and placement, holding off with VCTS
groups at this time. Wind field has been disrupted by passage of
an outflow boundary at KABI and near TAF issuance time at KSJT.
Winds overnight will veer from southeast to south. On Friday,
south winds in the morning will back to the southeast during the
afternoon.
19
&&
.PREV DISCUSSION... /ISSUED 646 PM CDT THU AUG 28 2014/
AVIATION...
/00Z TAFS/
Scattered showers and thunderstorms over west and northwest Texas
are slowly moving east this evening. A few of these may enter our
western and northwestern counties, through early tonight. Have
more uncertainty on whether any of our TAF sites will be
affected. KABI and KSJT may potentially be affected, and will
monitor radar trends for possible update and inclusion of TSRA.
Otherwise, high cloud cover from the aforementioned convection
will overspread West Central Texas this evening and early tonight.
On Friday, scattered showers and thunderstorms will be possible,
mainly during the afternoon and across the Big Country area north
of Interstate 20. Patchy low cloud development is possible toward
morning across some of our southern counties, and have a scattered
layer included at KSOA and KJCT. Southeast winds will veer to the
south overnight and continue on Friday morning.
PREV DISCUSSION... /ISSUED 340 PM CDT THU AUG 28 2014/
SHORT TERM...
(Tonight and Friday)
Rain chances for the next 24 hours continue to look more promising.
The latest WSR-88D data indicate showers and thunderstorms are
developing across the Big Country. The RUC indicates this activity
will continue to develop and spread into mainly our northwestern
counties during the next 6 hours. Overnight tonight, the NAM
fragments the QPF into small areas across mainly our northwestern
counties. Given the uncertainty across our southeastern counties,
slight chance PoPs still look good there. Elsewhere, and especially
north of our Interstate 20 corridor, chance PoPs look best. As the
upper trough axis pushes farther east tomorrow, the better rain
chances will expand south and include more of our southern counties.
The main thunderstorm threats for the next 24 hours are deadly
lightning and flash flooding from locally heavy rainfall.
Huber
LONG TERM...
(Friday night to Thursday)
While the upper trough will be east of the region Friday night and
Saturday, a weakly capped atmosphere will remain. Therefore,
isolated, mainly afternoon and evening showers and thunderstorms
will continue to be possible. The upper ridge strengthens Sunday,
however, with hot and dry conditions expected through next week.
Highs are expected mainly in the mid 90s.
04
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 72 93 72 96 73 / 50 30 20 20 10
San Angelo 73 94 72 96 74 / 30 30 20 20 10
Junction 73 93 73 95 74 / 20 20 20 20 10
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
1123 PM CDT THU AUG 28 2014
.AVIATION...TRANQUIL CONDITIONS ARE IN EFFECT ACROSS ALL OF SOUTH-
CENTRAL TEXAS. MINOR CHANGES WERE MADE TO THE EXISTING TAFS WITH A
COUPLE OF PERIODS APPENDED TO THE END OF MOST OF THE TAFS. VFR
WILL PREVAIL THROUGH THE NEXT HANDFUL OF HOURS UNTIL THE FORMATION
OF A DECK OF STRATUS AROUND 2K FEET INITIATES MVFR AS SURFACE
WINDS BECOME LIGHT. TOMORROW...WINDS WILL INCREASE TO MODERATE
LEVELS AS DAYTIME HEATING RESUMES VFR FOR THE AFTERNOON/EVENING
HOURS. WILL LET THE INCOMING SHIFT DETERMINE IF ANY CONVECTIVE
MARKERS (VCSH/TSRA) NEED TO BE INSERTED INTO ANY OF THE TAFS
AROUND SUNRISE FRIDAY MORNING...A REAL DEBATE SINCE THE OFFICIAL
FORECAST STILL SHOWS SCATTERED SHOWERS/THUNDERSTORMS WHILE MAV/MET
GUIDANCE LEANS MORE TOWARDS ISOLATED. MVFR SHOULD SET UP TOMORROW
NIGHT WITH SURFACE WINDS BECOMING NEARLY CALM AND CLOUD DECKS
LOWERING.
&&
.PREV DISCUSSION... /ISSUED 1109 PM CDT THU AUG 28 2014/
UPDATE...UPDATE TO INCLUDE 20 POPS FOR OVERNIGHT ACROSS THE
NORTHERN HILL COUNTRY AND PORTIONS OF EDWARDS PLATEAU. RADAR
TRENDS INDICATE ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS
ACROSS THE LOW ROLLING PLAINS OF NORTHWEST TEXAS HAVE PROGRESSED
SLIGHTLY FARTHER SOUTH AND EAST THAN SEVERAL MODELS WERE
INDICATING. WHILE EVENTUAL WEAKENING TREND IS EXPECTED...A FEW
SHOWERS MAY CLIP THE NORTHERN ROW OF COUNTIES BEFORE THIS
HAPPENS...INDICATED NOW BY HRRR AND RUC.
PREV DISCUSSION... /ISSUED 620 PM CDT THU AUG 28 2014/
AVIATION...TAFS INHERITED FROM THE PREVIOUS SHIFT LOOKED GREAT SO
NO MAJOR ADJUSTMENTS WERE MADE. THE ONLY SLIGHT CHANGES THAT WERE
MADE WERE TO INITIAL CONDITIONS AND TO APPEND A FM291900 PERIOD ON
THE END OF 3 OUT OF 4 OF THE TAFS. RADAR STILL SHOWING ISOLATED
SHOWERS IN THE VICINITY OF AUS...SO THE VCSH WAS RETAINED FOR THAT
TAF...DESPITE THE RECENT TREND OF RAPIDLY DIMINISHING CONVECTION
ACROSS THE VAST MAJORITY OF SOUTH-CENTRAL TEXAS. VFR WILL REIGN
THROUGH THE NEXT FEW HOURS UNTIL THE DEVELOPMENT OF A LOWERED
STRATUS DECK AROUND 2K FEET INITIATES MVFR CONDITIONS FOR 75
PERCENT OF THE TAF SITES. MVFR WILL CONTINUE THROUGH THE FRIDAY
MORNING HOURS UNTIL DAYTIME HEATING AND INCREASING SURFACE WINDS
RETURNS VFR TO THE AREA WITH RISING CLOUD DECKS LIKELY FOR THE
AFTERNOON AND EVENING HOURS. CURRENT FORECAST FOR FRIDAY INDICATES
SCATTERED (30 PERCENT) CONVECTION FOR THE DAY...HOWEVER MET/MAV
MODEL GUIDANCE ONLY SHOWS ISOLATED. CONSIDERED INCLUDING A VCSH IN
THE FM291900 PERIOD BASED ON THE CURRENT FORECAST...BUT WILL ALLOW
THE OVERNIGHT SHIFT TO ADDRESS THIS ISSUE USING MODEL GUIDANCE AND
FORECAST REASONING CLOSER TO THE FRIDAY TIME FRAME.
PREV DISCUSSION... /ISSUED 320 PM CDT THU AUG 28 2014/
SHORT TERM (TONIGHT THROUGH FRIDAY NIGHT)...
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE CONTINUING
EAST OF INTERSTATE 35 THIS AFTERNOON. THIS ACTIVITY IS IN RESPONSE
TO INCREASING MOISTURE AND LIFT ASSOCIATED WITH THE BROAD LOW
PRESSURE SYSTEM IN THE WESTERN GULF OF MEXICO. AS THE ACTIVITY
PUSHES WEST...NEAR THE I-35 CORRIDOR...THE SHOWERS AND STORMS ARE
DISSIPATING DUE TO LIMITED MOISTURE. DEW POINTS IN THESE LOCATIONS
ARE IN THE MIDDLE 60S VERSUS THE LOWER 70S IN THE SOUTHEASTERN
ZONES. THESE SHOWERS AND STORMS ARE PRIMARILY DIURNALLY DRIVEN
AND SHOULD WEAKEN AND DISSIPATE AROUND SUNSET.
LOWS TONIGHT ARE EXPECTED TO BE IN THE LOWER TO MIDDLE 70S ACROSS
MUCH OF THE AREA. THERE COULD BE SOME LEFT OVER SHOWERS AND STORMS
IN THE EASTERN ZONES AS WELL AS WEAKENING CONVECTION NEAR VAL
VERDE COUNTY THIS EVENING FROM STORMS MOVING EAST IN WEST TEXAS.
SOME OF THE HIGH-RES GUIDANCE IS HINTING AT OVERNIGHT STORMS
REGENERATING ACROSS THE EASTERN ZONES. THIS CAN BE SOMEWHAT
EXPECTED FROM TROPICAL SYSTEMS...THE MAIN QUESTIONS ARE IF AND
WHERE ANY CONVECTION WILL DEVELOP NEAR DAYBREAK. LOW POPS ACROSS
THE EASTERN ZONES SHOULD COVER THIS.
FRIDAY SHOULD BE SOMEWHAT SIMILAR TO TODAY. THE MAIN LIFT
ASSOCIATED WITH THE UPPER TROUGH CURRENTLY IN COLORADO WILL PUSH
NORTH OF THE AREA. THUS...THE MAIN LIFT WILL PASS NORTH AS WELL.
THERE SHOULD BE A WEAK SHEAR AXIS TO THE SOUTH OF THE LOW AND
THIS SHOULD ALLOW A SLIGHT INCREASE TO THE EXPECTED COVERAGE OF
SHOWERS AND THUNDERSTORMS FOR TOMORROW. PW VALUES WILL BE GREATER
THAN 2 INCHES FOR THE EASTERN ZONES AND SOME LOCALLY HEAVY
RAINFALL WILL BE POSSIBLE.
LONG TERM (SATURDAY THROUGH THURSDAY)...
LINGERING CONVECTION WILL REMAIN POSSIBLE SATURDAY ACROSS MUCH OF
THE AREA. THE LOW PRESSURE SYSTEM CURRENTLY IN THE GULF OF MEXICO
WILL BE SLOW TO MOVE AND WE WILL BE IN A FAVORABLE LOCATION OF
INCREASED MOISTURE AND DIURNAL LIFT ASSOCIATED WITH DAY TIME
HEATING. POPS WILL LINGER ACROSS THE EASTERN ZONES SUNDAY AND A
DRY FORECAST IS EXPECTED ON MONDAY AS WEAK RIDGING RETURNS TO THE
AREA. THE WEAK RIDGE SHIFTS EAST BY TUESDAY AND WILL KEEP LOW
CHANCES OF RAIN IN THE FORECAST FOR THE SOUTHEASTERN ZONES IN THE
EXTENDED FORECAST. 850 TEMPS NEXT WEEK REMAIN IN THE 18-22C RANGE
AND TEMPERATURES SHOULD REMAIN BELOW THE 100 DEGREE MARK FOR MOST
LOCATIONS.
HAMPSHIRE
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 76 95 76 94 76 / 10 30 20 20 10
AUSTIN BERGSTROM INTL AIRPORT 75 97 74 94 74 / 10 30 20 20 20
NEW BRAUNFELS MUNI AIRPORT 74 96 74 96 74 / 10 30 20 20 20
BURNET MUNI AIRPORT 74 93 74 94 75 / 20 30 20 20 10
DEL RIO INTL AIRPORT 78 99 77 99 77 / 10 20 20 10 10
GEORGETOWN MUNI AIRPORT 76 94 76 94 76 / 20 30 20 20 10
HONDO MUNI AIRPORT 74 96 73 97 74 / 10 20 20 20 10
SAN MARCOS MUNI AIRPORT 75 97 75 95 75 / 10 30 20 20 20
LA GRANGE - FAYETTE REGIONAL 77 95 76 93 76 / 20 40 20 40 20
SAN ANTONIO INTL AIRPORT 78 98 77 96 77 / 10 30 20 20 10
STINSON MUNI AIRPORT 77 97 77 97 76 / 10 30 20 20 20
&&
.EWX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
MESOSCALE/AVIATION...TOMASELLI
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
208 PM EDT FRI AUG 29 2014
.SYNOPSIS...
A WEAK FRONT WILL BE STATIONARY FROM NORTH CAROLINA TO MISSOURI
TODAY. THIS FRONT WILL LIFT NORTH INTO THE OHIO VALLEY TONIGHT. A
STRONGER SYSTEM WILL BRING A BETTER THREAT FOR SHOWERS AND STORMS
FOR SUNDAY AND MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1247 PM EDT FRIDAY...
LATEST LAPS DATA ARE SHOWING SURFACE BASED LI OF -2 TO -3 AND CAPS
AROUND 500 J/KG ACROSS TAZEWELL AND SMYTH COUNTIES. HIGHER VALUES
EXIST WEST OF THE FORECAST AREA IN SOUTHERN WEST VIRGINIA AND
NORTHEAST TENNESSEE. NO SHOWERS DETECTED YET ON REGIONAL RADARS IN
THAT REGION...BUT VISIBLE SATELLITE IMAGERY IS STARTING TO SHOW
THE DEVELOPMENT OF CUMULUS CLOUDS...SO AM NOT EXPECTING TOO LONG
OF WAIT FOR THE FIRST SHOWERS TO DEVELOP. LATEST HRRR AND RNK WRF-
ARW ARE ON TARGET FOR ABOUT A 18-19Z/2PM-3PM INITIATION TIME.
THE OTHER AREA OF THE REGION THAT WE HAVE BEEN WATCHING FOR
DEVELOPMENT IS SOUTHSIDE VIRGINIA AND NEIGHBORING NORTH CENTRAL
NORTH CAROLINA. THIS REGION HAS HAD DECENT CLOUD COVER OVER IT FOR
THE MORNING...AND NOW THE EARLY AFTERNOON. LAPS...AS
EXPECTED...STILL HAS THE AREA STABLE. FOR OUR FORECAST...HAVE
DELAYED THE ONSET OF ANY ISOLATED SHOWER OR THUNDERSTORM ACTIVITY
UNTIL LATER IN THE AFTERNOON...PERHAPS STARTING AROUND OR AFTER
21Z/5PM. HAVE ALSO LOWERED EXPECTED HIGH TEMPERATURES IN THIS AREA
BY A COUPLE OF DEGREES THANKS TO THE CLOUDS. HAVE RAISE FORECAST
HIGHS IN THE FAR WESTERN PARTS OF THE ARE BASED UPON CURRENT
TEMPERATURES AND CONTINUED WARMING TREND THROUGH THE AFTERNOON.
AS OF 947 AM EDT FRIDAY...
LATEST MESOSCALE MODELS STILL OFFERING BEST CHANCE FOR CONVECTION
TODAY TO BE ACROSS THE WESTERN QUARTER OF THE REGION. LATEST LAPS
DATA SHOW SURFACE BASED LI VALUES HAVE JUST DROPPED BELOW ZERO AND
A FEW HUNDRED SURFACE BASED CAPE HAVE DEVELOPED IN WESTERN
TAZEWELL AND SMYTH COUNTIES. THIS AREA AND THE SURROUNDING AREA IS
EXPECTED TO BECOME MORE UNSTABLE WITH THE HEATING OF THE
AFTERNOON. INITIAL CONVECTION TIME IS EXPECTED TO BE SOMEWHERE
BETWEEN 17Z-18Z/1PM-2PM IN THIS REGION AND MAINTAIN THROUGH THE
AFTERNOON. ANOTHER AREA WE ARE STILL WATCHING IS SOUTHSIDE
VIRGINIA AND NEIGHBORING PORTIONS OF NORTH CENTRAL NORTH
CAROLINA. WHILE STILL STABLE AT THE SURFACE...THIS AREA IS
EXPECTED TO BECOME UNSTABLE THIS AFTERNOON IN PROXIMITY TO THE
STALLED FRONTAL BOUNDARY. NO MAJOR CHANGES TO THE FORECAST.
AS OF 400 AM EDT FRIDAY...
STATIONARY FRONT TRAILED FROM NORTHEAST NORTH CAROLINA TO NORTH
CENTRAL TENNESSEE EARLY THIS MORNING.
ALONG THE BOUNDARY AND WEST OF THE BLUE RIDGE MODELS WERE SHOWING
A CHANCE OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON AND EVENING.
WILL BE STARTING OFF THE DAY CAPPED. EVEN IF THE CAP DOES
BREAK...AS SUGGESTED BY BUFKIT NAM/RAP GUIDANCE...NOT MUCH
INSTABILITY...AND NOT UNTIL AFTER 18Z. WITH THE SHORT WAVE ENERGY
WELL WEST AND NORTH OF THE FORECAST AREA...LITTLE TO AIDE IN THE
FORCING TODAY.
AXIS OF POOLED MOISTURE AND LOW LEVEL CONVERGENCE ALONG THE WEAK
BOUNDARY PIVOTS NORTHEAST TONIGHT AND WILL EXTEND FROM OHIO INTO
EASTERN NORTH CAROLINA BY SATURDAY MORNING.
WILL HAVE BEST PROBABILITY OF SHOWERS AND THUNDERSTORMS IN THE
EXTREME SOUTHWEST COUNTY WARNING AREA. AREAL COVERAGE OF
PRECIPITATION SHOULD ONLY BE ISOLATED TO SCATTERED. STORM MOTION
WOULD BRING THE STORMS INTO SOUTHEAST WEST VIRGINIA AND POSSIBLY THE
NEW RIVER VALLEY AROUND 00Z. BUT NOT MUCH INSTABILITY LEFT BY THAT
TIME.
SOUTHEAST WINDS AT THE SURFACE THROUGH LOW LEVELS...BRING 850-1000MB
RELATIVE HUMIDITY UP TODAY AND BY TONIGHT LOW CLOUDS ARE EXPECTED TO
ADVANCE TOWARD THE EAST SIDE OF THE APPALACHIANS.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 310 AM EDT FRIDAY...
UPPER RIDGE EXPECTED TO SHIFT EAST AS STRONGER UPPER TROUGH MOVES
FROM THE UPPER MIDWEST INTO THE GREAT LAKES. MODELS AGREE THAT A
SOUTHERN STREAM UPPER SHORTWAVE WITH ENHANCEMENT IN THE JET WILL
STREAK OVER THE GULF COAST STATES AND ACROSS THE WESTERN SLOPES OF
THE APPALACHIANS SUNDAY. FOR SATURDAY THOUGH...MAINLY LOOKING WEAK
FLOW ALOFT WITH SOME CONVERGENCE ACROSS THE MTNS PER SOUTH-SOUTHEAST
FLOW. MODELS ARE FAVORING A BIT OF CONVECTION WITH THE LEE TROUGH IN
THE EAST...MAINLY FROM THE EASTERN WV PANHANDLE SOUTHEAST TOWARD THE
TIDEWATER. THINK THE AIRMASS WILL BE UNSTABLE AND MOIST ENOUGH TO
TRIGGER A FEW STORMS BUT OVERALL UPPER SUPPORT IS LACKING SO ONLY
SEEING ISOLATED COVERAGE OVER THE MTNS AND NORTH OF A ROANOKE TO
DANVILLE LINE. MORE SUN SATURDAY WILL BRING TEMPS TOWARD 90 OUT EAST
WITH MID 80S WEST.
SAT NIGHT...MAIN AXIS OF CONVECTION WILL RUN FROM MS-KY...WITH
LITTLE TO NO CHANCE OF SHOWERS EAST OF THE BLUE RIDGE AFTER EVENING
STORMS WANE. WITH THE UPPER SUPPORT TRACKING CLOSER WILL HAVE AT
LEAST SLIGHT CHANCE INTO THE MOUNTAINS LATE.
SUNDAY LOOKS ACTIVE AS THE SHORTWAVE AXIS SHIFTS ACROSS KY INTO
NORTHERN WV...WITH STRONG CONVERGENCE AND LIFT. WILL SEE HIGH
CHANCE/LIKELY POPS. LOOKS LIKE CLOUD COVER COULD ARRIVE SOON ENOUGH
TO KEEP INSTABILITY LOWER...BUT ENOUGH UPPER SUPPORT/SHEAR WHERE A
FEW STORMS COULD PRODUCE GUSTY WINDS. THE SHORT WAVE AXIS SLOWLY
SHIFTS TO THE EAST AND WITH A LEE TROUGH...CONVECTION FIRES LATE IN
THE AFTERNOON AND MAY REMAIN OVER SOUTHSIDE UNTIL MIDNIGHT. HIGHS
SUNDAY WILL RANGE FROM THE UPPER 70S MOUNTAINS TO UPPER 80S TOWARDS
SOUTHSIDE.
OVERALL...LABOR DAY WEEKEND LOOKING VERY WARM/HOT/HUMID. SATURDAY
NOT TOO BAD RAIN WISE...BUT STAY COOL WHILE DRINKING PLENTY OF WATER
IF OUTDOORS. SUNDAY APPEARS POOR FOR OUTDOOR ACTIVITIES.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 300 PM EDT THURSDAY...
MUCH OF THE LONG TERM PERIOD WILL BE INFLUENCED BY A MEAN UPPER
RIDGE THAT WILL INITIALLY RESIDE ALONG AND OFF THE SOUTHEAST
COAST...WHICH GRADUALLY RETROGRESSES AND EXPANDS WESTWARD INTO THE
GULF COAST STATES BY THE END OF THE FORECAST PERIOD.
SOUTHEASTERN RIDGE WILL INITIALLY BE STRONG ENOUGH TO DEFLECT ANY
NORTHERN STREAM ENERGY AWAY FROM THE BLACKSBURG FORECAST AREA...WITH
MAIN BAROCLINIC ZONE REMAINING FROM THE NORTHERN PLAINS EAST INTO
AND THROUGH THE GREAT LAKES INTO NEW ENGLAND.
HOWEVER...TAP OF TROPICAL MOISTURE RIDING AROUND PERIPHERY OF
SOUTHEASTERN RIDGE LIKELY TO REMAIN OVER/NEAR THE BLACKSBURG
FORECAST AREA THROUGH AT LEAST MONDAY OR MONDAY NIGHT...MAINTAINING
THREAT FOR MAINLY DIURNALLY DRIVEN SCATTERED SHOWERS AND
THUNDERSTORMS...SOME OF WHICH MAY BE ACCOMPANIED BY LOCALLY HEAVY
RAIN CONSIDERING RELATIVELY HIGH PRECIPITABLE WATER VALUES EXPECTED
OVER THE AREA.
GRADUAL RETROGRESSION OF UPPER RIDGE INTO NORTHERN GULF COAST REGION
DURING THE MIDWEEK PERIOD SHOULD BE SUFFICIENT TO ALLOW WINDS ALOFT
TO VEER SUCH THAT INFLUENCE OF TROPICAL MOISTURE TAP GRADUALLY
WANES...ONLY TO BE REPLACED BY MORE AGGRESSIVE SOUTHWARD INTRUSION
OF NORTHERN STREAM ENERGY AND ASSOCIATED SCATTERED SHOWERS/STORMS IN
ADVANCE OF AN ACCOMPANYING DECAYING COOL FRONT INTO THE MID
APPALACHIAN AND MID ATLANTIC REGION IN TUESDAY-WEDNESDAY TIMEFRAME.
PUSH OF POST-FRONTAL SLIGHTLY DRIER AIR MAY BE STRONG ENOUGH TO
REDUCE THREAT FOR PRECIPITATION ACROSS AREAS NORTH OF INTERSTATE 64
BY THURSDAY...BUT WITH AT LEAST A CHANCE THREAT FOR SHOWERS/STORMS
REDEVELOPING BY AFTERNOON ACROSS THE SOUTHWESTERN MOUNTAINS CLOSER
TO DECAYING FRONTAL BOUNDARY AND PROXIMITY TO HIGHER THETA-E AIR.
PLENTY OF CLOUD COVER AND DEWPOINTS PRIMARILY IN THE 60S SHOULD
ENSURE THAT TEMPERATURES REMAIN CLOSE TO SEASONAL AVERAGES...MAINLY
MID 70S TO LOWER 80S ACROSS THE HIGHER ELEVATIONS BY DAY WITH UPPER
80S ACROSS THE PIEDMONT...WITH MAINLY 60S AT NIGHT. INTRUSION OF
SLIGHTLY COOLER/DRIER POST-FRONTAL AIR FROM THE NORTHEAST MAY ALLOW
TEMPERATURES TO BE A FEW DEGREES COOLER ON THURSDAY.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 130 PM EDT FRIDAY...
VISIBILITY SENSOR AT KDAN REMAINS INOPERABLE. PARTS ARE ON
ORDER. UNTIL REPAIRS COMPLETE...NO ADMENDMENTS WILL BE SCHEDULED.
MORNING MVFR STRATOCU CLOUDS OVER MUCH OF THE CENTRAL AND
SOUTHEASTERN PARTS OF THE REGION HAVE FINALLY ERODED...OR LIFTED
TO LOW END VFR SCT-BKN. THE ATMOSPHERE IS BECOMING UNSTABLE ACROSS
THE WESTERN PART OF THE REGION BETWEEN KBLF-KTNB. NEW MVFR-LOW END
VFR CUMULUS CLOUDS ARE DEVELOPING IN THIS REGION...AND ISOLATED
SHOWERS AND PERHAPS A FEW THUNDERSTORMS ARE EXPECTED THIS
AFTERNOON INTO THE EARLY EVENING IN THIS REGION.
OVERNIGHT...A STATIONARY FRONT WILL MAKE SOME PROGRESS NORTH AS A
WARM FRONT ALONG WITH SOME PATCHY SHOWERS SOUTH OF IT. LOW LEVEL
MOISTURE WILL INCREASE AN BECOME TRAPPED UNDER THE NOCTURNAL
INVERSION. ANTICIPATE MOST OF THE REGION TO DEVELOP MVFR CIGS WITH
SOME REGIONS OF IFR. VSBYS WILL ALSO DECREASE WITH MOST AREAS
HAVING MVFR WITH POCKETS OF IFR.
ANY SUB-VFR CONDITIONS WILL BE FAIRLY SLOW TO IMPROVE TO VFR AFTER
SUNRISE SATURDAY. 15Z/11AM IS THE MOST LIKELY TIME MOST OF THE
REGION WILL BE BACK TO VFR.
EXTENDED DISCUSSION...
ANY ISOLATED OR SCATTERED SHOWERS AND STORMS WILL BE MAINLY
CONFINED TO AN AREA ALONG AND NORTH OF A KHSP-KFVX LINE SATURDAY
AFTERNOON...JUST SOUTH OF THE AGAIN STALLED FRONTAL BOUNDARY.
LATE SATURDAY NIGHT THROUGH SUNDAY EVENING AN AREA OF LOW PRESSURE
WILL HEAD EASTWARD THROUGH THE GREAT LAKES REGION TOWARD NEW
ENGLAND. ITS ASSOCIATED COLD FRONT WILL SWEEP THROUGH THE REGION
BRINGING A GENEROUS COVERAGE OF SHOWERS AND SOME STORMS. SUB-VFR
CONDITIONS ARE EXPECTED TO ACCOMPANY THE SYSTEM AND PRECIPITATION.
ANOTHER COLD FRONT IS EXPECTED TO PRODUCE SIMILAR CIRCUMSTANCES
TUESDAY INTO TUESDAY NIGHT. HOWEVER...MODEL GUIDANCE FOR THIS ONE
OFFERS PRECIPITATION IN A MORE SCATTERED DISTRIBUTION. AS
SUCH...THE MAGNITUDE OF SUB-VFR CONDITIONS MAY BE LESS.
&&
.EQUIPMENT...
AS OF 730 AM EDT FRIDAY ...
THE VISIBILITY SENSOR AT KDAN...DANVILLE REGIONAL AIRPORT...WILL
BE OUT OF SERVICE UNTIL FURTHER NOTICE. A PART HAS BEEN BACK-ORDERED.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/DS
SHORT TERM...RCS
LONG TERM...WERT
AVIATION...DS
EQUIPMENT...AMS
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1254 PM EDT FRI AUG 29 2014
.SYNOPSIS...
A WEAK FRONT WILL BE STATIONARY FROM NORTH CAROLINA TO MISSOURI
TODAY. THIS FRONT WILL LIFT NORTH INTO THE OHIO VALLEY TONIGHT. A
STRONGER SYSTEM WILL BRING A BETTER THREAT FOR SHOWERS AND STORMS
FOR SUNDAY AND MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1247 PM EDT FRIDAY...
LATEST LAPS DATA ARE SHOWING SURFACE BASED LI OF -2 TO -3 AND CAPS
AROUND 500 J/KG ACROSS TAZEWELL AND SMYTH COUNTIES. HIGHER VALUES
EXIST WEST OF THE FORECAST AREA IN SOUTHERN WEST VIRGINIA AND
NORTHEAST TENNESSEE. NO SHOWERS DETECTED YET ON REGIONAL RADARS IN
THAT REGION...BUT VISIBLE SATELLITE IMAGERY IS STARTING TO SHOW
THE DEVELOPMENT OF CUMULUS CLOUDS...SO AM NOT EXPECTING TOO LONG
OF WAIT FOR THE FIRST SHOWERS TO DEVELOP. LATEST HRRR AND RNK WRF-
ARW ARE ON TARGET FOR ABOUT A 18-19Z/2PM-3PM INITIATION TIME.
THE OTHER AREA OF THE REGION THAT WE HAVE BEEN WATCHING FOR
DEVELOPMENT IS SOUTHSIDE VIRGINIA AND NEIGHBORING NORTH CENTRAL
NORTH CAROLINA. THIS REGION HAS HAD DECENT CLOUD COVER OVER IT FOR
THE MORNING...AND NOW THE EARLY AFTERNOON. LAPS...AS
EXPECTED...STILL HAS THE AREA STABLE. FOR OUR FORECAST...HAVE
DELAYED THE ONSET OF ANY ISOLATED SHOWER OR THUNDERSTORM ACTIVITY
UNTIL LATER IN THE AFTERNOON...PERHAPS STARTING AROUND OR AFTER
21Z/5PM. HAVE ALSO LOWERED EXPECTED HIGH TEMPERATURES IN THIS AREA
BY A COUPLE OF DEGREES THANKS TO THE CLOUDS. HAVE RAISE FORECAST
HIGHS IN THE FAR WESTERN PARTS OF THE ARE BASED UPON CURRENT
TEMPERATURES AND CONTINUED WARMING TREND THROUGH THE AFTERNOON.
AS OF 947 AM EDT FRIDAY...
LATEST MESOSCALE MODELS STILL OFFERING BEST CHANCE FOR CONVECTION
TODAY TO BE ACROSS THE WESTERN QUARTER OF THE REGION. LATEST LAPS
DATA SHOW SURFACE BASED LI VALUES HAVE JUST DROPPED BELOW ZERO AND
A FEW HUNDRED SURFACE BASED CAPE HAVE DEVELOPED IN WESTERN
TAZEWELL AND SMYTH COUNTIES. THIS AREA AND THE SURROUNDING AREA IS
EXPECTED TO BECOME MORE UNSTABLE WITH THE HEATING OF THE
AFTERNOON. INITIAL CONVECTION TIME IS EXPECTED TO BE SOMEWHERE
BETWEEN 17Z-18Z/1PM-2PM IN THIS REGION AND MAINTAIN THROUGH THE
AFTERNOON. ANOTHER AREA WE ARE STILL WATCHING IS SOUTHSIDE
VIRGINIA AND NEIGHBORING PORTIONS OF NORTH CENTRAL NORTH
CAROLINA. WHILE STILL STABLE AT THE SURFACE...THIS AREA IS
EXPECTED TO BECOME UNSTABLE THIS AFTERNOON IN PROXIMITY TO THE
STALLED FRONTAL BOUNDARY. NO MAJOR CHANGES TO THE FORECAST.
AS OF 400 AM EDT FRIDAY...
STATIONARY FRONT TRAILED FROM NORTHEAST NORTH CAROLINA TO NORTH
CENTRAL TENNESSEE EARLY THIS MORNING.
ALONG THE BOUNDARY AND WEST OF THE BLUE RIDGE MODELS WERE SHOWING
A CHANCE OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON AND EVENING.
WILL BE STARTING OFF THE DAY CAPPED. EVEN IF THE CAP DOES
BREAK...AS SUGGESTED BY BUFKIT NAM/RAP GUIDANCE...NOT MUCH
INSTABILITY...AND NOT UNTIL AFTER 18Z. WITH THE SHORT WAVE ENERGY
WELL WEST AND NORTH OF THE FORECAST AREA...LITTLE TO AIDE IN THE
FORCING TODAY.
AXIS OF POOLED MOISTURE AND LOW LEVEL CONVERGENCE ALONG THE WEAK
BOUNDARY PIVOTS NORTHEAST TONIGHT AND WILL EXTEND FROM OHIO INTO
EASTERN NORTH CAROLINA BY SATURDAY MORNING.
WILL HAVE BEST PROBABILITY OF SHOWERS AND THUNDERSTORMS IN THE
EXTREME SOUTHWEST COUNTY WARNING AREA. AREAL COVERAGE OF
PRECIPITATION SHOULD ONLY BE ISOLATED TO SCATTERED. STORM MOTION
WOULD BRING THE STORMS INTO SOUTHEAST WEST VIRGINIA AND POSSIBLY THE
NEW RIVER VALLEY AROUND 00Z. BUT NOT MUCH INSTABILITY LEFT BY THAT
TIME.
SOUTHEAST WINDS AT THE SURFACE THROUGH LOW LEVELS...BRING 850-1000MB
RELATIVE HUMIDITY UP TODAY AND BY TONIGHT LOW CLOUDS ARE EXPECTED TO
ADVANCE TOWARD THE EAST SIDE OF THE APPALACHIANS.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 310 AM EDT FRIDAY...
UPPER RIDGE EXPECTED TO SHIFT EAST AS STRONGER UPPER TROUGH MOVES
FROM THE UPPER MIDWEST INTO THE GREAT LAKES. MODELS AGREE THAT A
SOUTHERN STREAM UPPER SHORTWAVE WITH ENHANCEMENT IN THE JET WILL
STREAK OVER THE GULF COAST STATES AND ACROSS THE WESTERN SLOPES OF
THE APPALACHIANS SUNDAY. FOR SATURDAY THOUGH...MAINLY LOOKING WEAK
FLOW ALOFT WITH SOME CONVERGENCE ACROSS THE MTNS PER SOUTH-SOUTHEAST
FLOW. MODELS ARE FAVORING A BIT OF CONVECTION WITH THE LEE TROUGH IN
THE EAST...MAINLY FROM THE EASTERN WV PANHANDLE SOUTHEAST TOWARD THE
TIDEWATER. THINK THE AIRMASS WILL BE UNSTABLE AND MOIST ENOUGH TO
TRIGGER A FEW STORMS BUT OVERALL UPPER SUPPORT IS LACKING SO ONLY
SEEING ISOLATED COVERAGE OVER THE MTNS AND NORTH OF A ROANOKE TO
DANVILLE LINE. MORE SUN SATURDAY WILL BRING TEMPS TOWARD 90 OUT EAST
WITH MID 80S WEST.
SAT NIGHT...MAIN AXIS OF CONVECTION WILL RUN FROM MS-KY...WITH
LITTLE TO NO CHANCE OF SHOWERS EAST OF THE BLUE RIDGE AFTER EVENING
STORMS WANE. WITH THE UPPER SUPPORT TRACKING CLOSER WILL HAVE AT
LEAST SLIGHT CHANCE INTO THE MOUNTAINS LATE.
SUNDAY LOOKS ACTIVE AS THE SHORTWAVE AXIS SHIFTS ACROSS KY INTO
NORTHERN WV...WITH STRONG CONVERGENCE AND LIFT. WILL SEE HIGH
CHANCE/LIKELY POPS. LOOKS LIKE CLOUD COVER COULD ARRIVE SOON ENOUGH
TO KEEP INSTABILITY LOWER...BUT ENOUGH UPPER SUPPORT/SHEAR WHERE A
FEW STORMS COULD PRODUCE GUSTY WINDS. THE SHORT WAVE AXIS SLOWLY
SHIFTS TO THE EAST AND WITH A LEE TROUGH...CONVECTION FIRES LATE IN
THE AFTERNOON AND MAY REMAIN OVER SOUTHSIDE UNTIL MIDNIGHT. HIGHS
SUNDAY WILL RANGE FROM THE UPPER 70S MOUNTAINS TO UPPER 80S TOWARDS
SOUTHSIDE.
OVERALL...LABOR DAY WEEKEND LOOKING VERY WARM/HOT/HUMID. SATURDAY
NOT TOO BAD RAIN WISE...BUT STAY COOL WHILE DRINKING PLENTY OF WATER
IF OUTDOORS. SUNDAY APPEARS POOR FOR OUTDOOR ACTIVITIES.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 300 PM EDT THURSDAY...
MUCH OF THE LONG TERM PERIOD WILL BE INFLUENCED BY A MEAN UPPER
RIDGE THAT WILL INITIALLY RESIDE ALONG AND OFF THE SOUTHEAST
COAST...WHICH GRADUALLY RETROGRESSES AND EXPANDS WESTWARD INTO THE
GULF COAST STATES BY THE END OF THE FORECAST PERIOD.
SOUTHEASTERN RIDGE WILL INITIALLY BE STRONG ENOUGH TO DEFLECT ANY
NORTHERN STREAM ENERGY AWAY FROM THE BLACKSBURG FORECAST AREA...WITH
MAIN BAROCLINIC ZONE REMAINING FROM THE NORTHERN PLAINS EAST INTO
AND THROUGH THE GREAT LAKES INTO NEW ENGLAND.
HOWEVER...TAP OF TROPICAL MOISTURE RIDING AROUND PERIPHERY OF
SOUTHEASTERN RIDGE LIKELY TO REMAIN OVER/NEAR THE BLACKSBURG
FORECAST AREA THROUGH AT LEAST MONDAY OR MONDAY NIGHT...MAINTAINING
THREAT FOR MAINLY DIURNALLY DRIVEN SCATTERED SHOWERS AND
THUNDERSTORMS...SOME OF WHICH MAY BE ACCOMPANIED BY LOCALLY HEAVY
RAIN CONSIDERING RELATIVELY HIGH PRECIPITABLE WATER VALUES EXPECTED
OVER THE AREA.
GRADUAL RETROGRESSION OF UPPER RIDGE INTO NORTHERN GULF COAST REGION
DURING THE MIDWEEK PERIOD SHOULD BE SUFFICIENT TO ALLOW WINDS ALOFT
TO VEER SUCH THAT INFLUENCE OF TROPICAL MOISTURE TAP GRADUALLY
WANES...ONLY TO BE REPLACED BY MORE AGGRESSIVE SOUTHWARD INTRUSION
OF NORTHERN STREAM ENERGY AND ASSOCIATED SCATTERED SHOWERS/STORMS IN
ADVANCE OF AN ACCOMPANYING DECAYING COOL FRONT INTO THE MID
APPALACHIAN AND MID ATLANTIC REGION IN TUESDAY-WEDNESDAY TIMEFRAME.
PUSH OF POST-FRONTAL SLIGHTLY DRIER AIR MAY BE STRONG ENOUGH TO
REDUCE THREAT FOR PRECIPITATION ACROSS AREAS NORTH OF INTERSTATE 64
BY THURSDAY...BUT WITH AT LEAST A CHANCE THREAT FOR SHOWERS/STORMS
REDEVELOPING BY AFTERNOON ACROSS THE SOUTHWESTERN MOUNTAINS CLOSER
TO DECAYING FRONTAL BOUNDARY AND PROXIMITY TO HIGHER THETA-E AIR.
PLENTY OF CLOUD COVER AND DEWPOINTS PRIMARILY IN THE 60S SHOULD
ENSURE THAT TEMPERATURES REMAIN CLOSE TO SEASONAL AVERAGES...MAINLY
MID 70S TO LOWER 80S ACROSS THE HIGHER ELEVATIONS BY DAY WITH UPPER
80S ACROSS THE PIEDMONT...WITH MAINLY 60S AT NIGHT. INTRUSION OF
SLIGHTLY COOLER/DRIER POST-FRONTAL AIR FROM THE NORTHEAST MAY ALLOW
TEMPERATURES TO BE A FEW DEGREES COOLER ON THURSDAY.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 745 AM EDT FRIDAY...
A STATIONARY FRONT EXTENDED FROM AROUND NORTH CAROLINA TO
MISSOURI. THIS FRONT WILL MOVE LITTLE TODAY THEN WILL PUSH NORTH
TONIGHT...INTO THE OHIO VALLEY BY SATURDAY MORNING.
STRATOCUMULUS HAD FILLED IN OVER SOUTHERN VIRGINIA AND NORTHERN
NORTH CAROLINA EARLY THIS MORNING WITH MVFR TO LOW END VFR
CEILINGS. EXPECT THESE CLOUDS TO BECOME SCATTERED BY THIS
AFTERNOON.
THE BEST PROBABILITY OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON
AND EVENING WILL JUST SOUTH OF KBLF AND KBCB. STORM MOTION MAY
TAKE THE STORMS CLOSE TO THESE AIRPORTS AROUND 00Z/8PM...BUT
PROBABILITY IS TOO LOW AT THIS TIME TO MENTION IN THE TAFS.
MODELS SHOWED HIGH AMOUNTS OF LOW NEAR THE SURFACE ALONG AND EAST
OF THE BLUE RIDGE LATE TONIGHT. HIGH CONFIDENCE OF AT LEAST MVFR
CEILINGS AT KLYH AND KDAN AFTER 06Z/2AM. NOT AS MUCH A SURE THING
AT KROA...BUT STILL CONFIDENT ENOUGH TO ADD MVFR CEILINGS TO THE
TAF. IT IS POSSIBLE THAT CEILINGS MAY LOWER ALL THE WAY TO IFR
LEVELS BEFORE THE 12Z/8AM END OF THE TAF PERIOD AS THIS STRATUS
EXPANDS TO THE WEST.
EXTENDED DISCUSSION...
WIDELY SCATTERED SHOWERS AND THUNDERSTORMS WILL AFFECT THE REGION
AGAIN ON SATURDAY...MAINLY DURING THE LATE AFTERNOON AND EARLY
EVENING. SHOULD ONE OF THESE STORMS DEVELOP NEAR A TAF LOCATION IT
COULD RESULT IN A BRIEF PERIOD OF SUB VFR CONDITIONS.
AN AREA OF LOW PRESSURE IS FORECAST TO MOVE THROUGH THE GREAT
LAKES SATURDAY NIGHT AND SUNDAY...THE ASSOCIATED COLD FRONT
TRAILING SOUTH AND MOVING ACROSS THE OHIO/TN VALLEYS. SHOWERS AND
THUNDERSTORMS WILL LIKELY BE ASSOCIATED WITH THIS FRONT...THIS
ACTIVITY SPREADING EAST INTO THE CENTRAL APPALACHIANS SUNDAY AND
MONDAY. SHOWER COVERAGE SUNDAY THROUGH TUESDAY IS EXPECTED TO BE
MORE WIDESPREAD AS COMPARED TO FRIDAY AND SATURDAY.
&&
.EQUIPMENT...
AS OF 730 AM EDT FRIDAY ...
THE VISIBILITY SENSOR AT KDAN...DANVILLE REGIONAL AIRPORT...WILL
BE OUT OF SERVICE UNTIL FURTHER NOTICE. A PART HAS BEEN BACK-ORDERED.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/DS
SHORT TERM...RCS
LONG TERM...WERT
AVIATION...AMS/CF
EQUIPMENT...AMS
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1253 PM EDT FRI AUG 29 2014
.SYNOPSIS...
A WEAK FRONT WILL BE STATIONARY FROM NORTH CAROLINA TO MISSOURI
TODAY. THIS FRONT WILL LIFT NORTH INTO THE OHIO VALLEY TONIGHT. A
STRONGER SYSTEM WILL BRING A BETTER THREAT FOR SHOWERS AND STORMS
FOR SUNDAY AND MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1247 PM EDT FRIDAY...
LATEST LAPS DATA ARE SHOWING SURFACE BASED LI OF -2 TO -3 AND CAPS
AROUND 500 J/GS ACROSS TAZEWELL AND SMYTH COUNTIES. HIGHER VALUES
EXIST WEST OF THE FORECAST AREA IN SOUTHERN WEST VIRGINIA AND
NORTHEAST TENNESSEE. NO SHOWERS DETECTED YET ON REGIONAL RADARS IN
THAT REGION...BUT VISIBLE SATELLITE IMAGERY IS STARTING TO SHOW
THE DEVELOPMENT OF CUMULUS CLOUDS...SO AM NOT EXPECTING TOO LONG
OF WAIT FOR THE FIRST SHOWERS TO DEVELOP. LATEST HRRR AND RNK
WRF-ARW ARE ON TARGET FOR ABOUT A 18-19Z/2PM-3PM INITIATION TIME.
THE OTHER AREA OF THE REGION THAT WE HAVE BEEN WATCHING FOR
DEVELOPMENT IS SOUTHSIDE VIRGINIA AND NEIGHBORING NORTH CENTRAL
NORTH CAROLINA. THIS REGION HAS HAD DECENT CLOUD COVER OVER IT FOR
THE MORNING...AND NOW THE EARLY AFTERNOON. LAPS...AS
EXPECTED...STILL HAS THE AREA STABLE. FOR OUR FORECAST...HAVE
DELAYED THE ONSET OF ANY ISOLATED SHOWER OR THUNDERSTORM ACTIVITY
UNTIL LATER IN THE AFTERNOON...PERHAPS STARTING AROUND OR AFTER
21Z/5PM. HAVE ALSO LOWERED EXPECTED HIGH TEMPERATURES IN THIS AREA
BY A COUPLE OF DEGREES THANKS TO THE CLOUDS. HAVE RAISE FORECAST
HIGHS IN THE FAR WESTERN PARTS OF THE ARE BASED UPON CURRENT
TEMPERATURES AND CONTINUED WARMING TREND THROUGH THE AFTERNOON.
AS OF 947 AM EDT FRIDAY...
LATEST MESOSCALE MODELS STILL OFFERING BEST CHANCE FOR CONVECTION
TODAY TO BE ACROSS THE WESTERN QUARTER OF THE REGION. LATEST LAPS
DATA SHOW SURFACE BASED LI VALUES HAVE JUST DROPPED BELOW ZERO AND
A FEW HUNDRED SURFACE BASED CAPE HAVE DEVELOPED IN WESTERN
TAZEWELL AND SMYTH COUNTIES. THIS AREA AND THE SURROUNDING AREA IS
EXPECTED TO BECOME MORE UNSTABLE WITH THE HEATING OF THE
AFTERNOON. INITIAL CONVECTION TIME IS EXPECTED TO BE SOMEWHERE
BETWEEN 17Z-18Z/1PM-2PM IN THIS REGION AND MAINTAIN THROUGH THE
AFTERNOON. ANOTHER AREA WE ARE STILL WATCHING IS SOUTHSIDE
VIRGINIA AND NEIGHBORING PORTIONS OF NORTH CENTRAL NORTH
CAROLINA. WHILE STILL STABLE AT THE SURFACE...THIS AREA IS
EXPECTED TO BECOME UNSTABLE THIS AFTERNOON IN PROXIMITY TO THE
STALLED FRONTAL BOUNDARY. NO MAJOR CHANGES TO THE FORECAST.
AS OF 400 AM EDT FRIDAY...
STATIONARY FRONT TRAILED FROM NORTHEAST NORTH CAROLINA TO NORTH
CENTRAL TENNESSEE EARLY THIS MORNING.
ALONG THE BOUNDARY AND WEST OF THE BLUE RIDGE MODELS WERE SHOWING
A CHANCE OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON AND EVENING.
WILL BE STARTING OFF THE DAY CAPPED. EVEN IF THE CAP DOES
BREAK...AS SUGGESTED BY BUFKIT NAM/RAP GUIDANCE...NOT MUCH
INSTABILITY...AND NOT UNTIL AFTER 18Z. WITH THE SHORT WAVE ENERGY
WELL WEST AND NORTH OF THE FORECAST AREA...LITTLE TO AIDE IN THE
FORCING TODAY.
AXIS OF POOLED MOISTURE AND LOW LEVEL CONVERGENCE ALONG THE WEAK
BOUNDARY PIVOTS NORTHEAST TONIGHT AND WILL EXTEND FROM OHIO INTO
EASTERN NORTH CAROLINA BY SATURDAY MORNING.
WILL HAVE BEST PROBABILITY OF SHOWERS AND THUNDERSTORMS IN THE
EXTREME SOUTHWEST COUNTY WARNING AREA. AREAL COVERAGE OF
PRECIPITATION SHOULD ONLY BE ISOLATED TO SCATTERED. STORM MOTION
WOULD BRING THE STORMS INTO SOUTHEAST WEST VIRGINIA AND POSSIBLY THE
NEW RIVER VALLEY AROUND 00Z. BUT NOT MUCH INSTABILITY LEFT BY THAT
TIME.
SOUTHEAST WINDS AT THE SURFACE THROUGH LOW LEVELS...BRING 850-1000MB
RELATIVE HUMIDITY UP TODAY AND BY TONIGHT LOW CLOUDS ARE EXPECTED TO
ADVANCE TOWARD THE EAST SIDE OF THE APPALACHIANS.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 310 AM EDT FRIDAY...
UPPER RIDGE EXPECTED TO SHIFT EAST AS STRONGER UPPER TROUGH MOVES
FROM THE UPPER MIDWEST INTO THE GREAT LAKES. MODELS AGREE THAT A
SOUTHERN STREAM UPPER SHORTWAVE WITH ENHANCEMENT IN THE JET WILL
STREAK OVER THE GULF COAST STATES AND ACROSS THE WESTERN SLOPES OF
THE APPALACHIANS SUNDAY. FOR SATURDAY THOUGH...MAINLY LOOKING WEAK
FLOW ALOFT WITH SOME CONVERGENCE ACROSS THE MTNS PER SOUTH-SOUTHEAST
FLOW. MODELS ARE FAVORING A BIT OF CONVECTION WITH THE LEE TROUGH IN
THE EAST...MAINLY FROM THE EASTERN WV PANHANDLE SOUTHEAST TOWARD THE
TIDEWATER. THINK THE AIRMASS WILL BE UNSTABLE AND MOIST ENOUGH TO
TRIGGER A FEW STORMS BUT OVERALL UPPER SUPPORT IS LACKING SO ONLY
SEEING ISOLATED COVERAGE OVER THE MTNS AND NORTH OF A ROANOKE TO
DANVILLE LINE. MORE SUN SATURDAY WILL BRING TEMPS TOWARD 90 OUT EAST
WITH MID 80S WEST.
SAT NIGHT...MAIN AXIS OF CONVECTION WILL RUN FROM MS-KY...WITH
LITTLE TO NO CHANCE OF SHOWERS EAST OF THE BLUE RIDGE AFTER EVENING
STORMS WANE. WITH THE UPPER SUPPORT TRACKING CLOSER WILL HAVE AT
LEAST SLIGHT CHANCE INTO THE MOUNTAINS LATE.
SUNDAY LOOKS ACTIVE AS THE SHORTWAVE AXIS SHIFTS ACROSS KY INTO
NORTHERN WV...WITH STRONG CONVERGENCE AND LIFT. WILL SEE HIGH
CHANCE/LIKELY POPS. LOOKS LIKE CLOUD COVER COULD ARRIVE SOON ENOUGH
TO KEEP INSTABILITY LOWER...BUT ENOUGH UPPER SUPPORT/SHEAR WHERE A
FEW STORMS COULD PRODUCE GUSTY WINDS. THE SHORT WAVE AXIS SLOWLY
SHIFTS TO THE EAST AND WITH A LEE TROUGH...CONVECTION FIRES LATE IN
THE AFTERNOON AND MAY REMAIN OVER SOUTHSIDE UNTIL MIDNIGHT. HIGHS
SUNDAY WILL RANGE FROM THE UPPER 70S MOUNTAINS TO UPPER 80S TOWARDS
SOUTHSIDE.
OVERALL...LABOR DAY WEEKEND LOOKING VERY WARM/HOT/HUMID. SATURDAY
NOT TOO BAD RAIN WISE...BUT STAY COOL WHILE DRINKING PLENTY OF WATER
IF OUTDOORS. SUNDAY APPEARS POOR FOR OUTDOOR ACTIVITIES.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 300 PM EDT THURSDAY...
MUCH OF THE LONG TERM PERIOD WILL BE INFLUENCED BY A MEAN UPPER
RIDGE THAT WILL INITIALLY RESIDE ALONG AND OFF THE SOUTHEAST
COAST...WHICH GRADUALLY RETROGRESSES AND EXPANDS WESTWARD INTO THE
GULF COAST STATES BY THE END OF THE FORECAST PERIOD.
SOUTHEASTERN RIDGE WILL INITIALLY BE STRONG ENOUGH TO DEFLECT ANY
NORTHERN STREAM ENERGY AWAY FROM THE BLACKSBURG FORECAST AREA...WITH
MAIN BAROCLINIC ZONE REMAINING FROM THE NORTHERN PLAINS EAST INTO
AND THROUGH THE GREAT LAKES INTO NEW ENGLAND.
HOWEVER...TAP OF TROPICAL MOISTURE RIDING AROUND PERIPHERY OF
SOUTHEASTERN RIDGE LIKELY TO REMAIN OVER/NEAR THE BLACKSBURG
FORECAST AREA THROUGH AT LEAST MONDAY OR MONDAY NIGHT...MAINTAINING
THREAT FOR MAINLY DIURNALLY DRIVEN SCATTERED SHOWERS AND
THUNDERSTORMS...SOME OF WHICH MAY BE ACCOMPANIED BY LOCALLY HEAVY
RAIN CONSIDERING RELATIVELY HIGH PRECIPITABLE WATER VALUES EXPECTED
OVER THE AREA.
GRADUAL RETROGRESSION OF UPPER RIDGE INTO NORTHERN GULF COAST REGION
DURING THE MIDWEEK PERIOD SHOULD BE SUFFICIENT TO ALLOW WINDS ALOFT
TO VEER SUCH THAT INFLUENCE OF TROPICAL MOISTURE TAP GRADUALLY
WANES...ONLY TO BE REPLACED BY MORE AGGRESSIVE SOUTHWARD INTRUSION
OF NORTHERN STREAM ENERGY AND ASSOCIATED SCATTERED SHOWERS/STORMS IN
ADVANCE OF AN ACCOMPANYING DECAYING COOL FRONT INTO THE MID
APPALACHIAN AND MID ATLANTIC REGION IN TUESDAY-WEDNESDAY TIMEFRAME.
PUSH OF POST-FRONTAL SLIGHTLY DRIER AIR MAY BE STRONG ENOUGH TO
REDUCE THREAT FOR PRECIPITATION ACROSS AREAS NORTH OF INTERSTATE 64
BY THURSDAY...BUT WITH AT LEAST A CHANCE THREAT FOR SHOWERS/STORMS
REDEVELOPING BY AFTERNOON ACROSS THE SOUTHWESTERN MOUNTAINS CLOSER
TO DECAYING FRONTAL BOUNDARY AND PROXIMITY TO HIGHER THETA-E AIR.
PLENTY OF CLOUD COVER AND DEWPOINTS PRIMARILY IN THE 60S SHOULD
ENSURE THAT TEMPERATURES REMAIN CLOSE TO SEASONAL AVERAGES...MAINLY
MID 70S TO LOWER 80S ACROSS THE HIGHER ELEVATIONS BY DAY WITH UPPER
80S ACROSS THE PIEDMONT...WITH MAINLY 60S AT NIGHT. INTRUSION OF
SLIGHTLY COOLER/DRIER POST-FRONTAL AIR FROM THE NORTHEAST MAY ALLOW
TEMPERATURES TO BE A FEW DEGREES COOLER ON THURSDAY.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 745 AM EDT FRIDAY...
A STATIONARY FRONT EXTENDED FROM AROUND NORTH CAROLINA TO
MISSOURI. THIS FRONT WILL MOVE LITTLE TODAY THEN WILL PUSH NORTH
TONIGHT...INTO THE OHIO VALLEY BY SATURDAY MORNING.
STRATOCUMULUS HAD FILLED IN OVER SOUTHERN VIRGINIA AND NORTHERN
NORTH CAROLINA EARLY THIS MORNING WITH MVFR TO LOW END VFR
CEILINGS. EXPECT THESE CLOUDS TO BECOME SCATTERED BY THIS
AFTERNOON.
THE BEST PROBABILITY OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON
AND EVENING WILL JUST SOUTH OF KBLF AND KBCB. STORM MOTION MAY
TAKE THE STORMS CLOSE TO THESE AIRPORTS AROUND 00Z/8PM...BUT
PROBABILITY IS TOO LOW AT THIS TIME TO MENTION IN THE TAFS.
MODELS SHOWED HIGH AMOUNTS OF LOW NEAR THE SURFACE ALONG AND EAST
OF THE BLUE RIDGE LATE TONIGHT. HIGH CONFIDENCE OF AT LEAST MVFR
CEILINGS AT KLYH AND KDAN AFTER 06Z/2AM. NOT AS MUCH A SURE THING
AT KROA...BUT STILL CONFIDENT ENOUGH TO ADD MVFR CEILINGS TO THE
TAF. IT IS POSSIBLE THAT CEILINGS MAY LOWER ALL THE WAY TO IFR
LEVELS BEFORE THE 12Z/8AM END OF THE TAF PERIOD AS THIS STRATUS
EXPANDS TO THE WEST.
EXTENDED DISCUSSION...
WIDELY SCATTERED SHOWERS AND THUNDERSTORMS WILL AFFECT THE REGION
AGAIN ON SATURDAY...MAINLY DURING THE LATE AFTERNOON AND EARLY
EVENING. SHOULD ONE OF THESE STORMS DEVELOP NEAR A TAF LOCATION IT
COULD RESULT IN A BRIEF PERIOD OF SUB VFR CONDITIONS.
AN AREA OF LOW PRESSURE IS FORECAST TO MOVE THROUGH THE GREAT
LAKES SATURDAY NIGHT AND SUNDAY...THE ASSOCIATED COLD FRONT
TRAILING SOUTH AND MOVING ACROSS THE OHIO/TN VALLEYS. SHOWERS AND
THUNDERSTORMS WILL LIKELY BE ASSOCIATED WITH THIS FRONT...THIS
ACTIVITY SPREADING EAST INTO THE CENTRAL APPALACHIANS SUNDAY AND
MONDAY. SHOWER COVERAGE SUNDAY THROUGH TUESDAY IS EXPECTED TO BE
MORE WIDESPREAD AS COMPARED TO FRIDAY AND SATURDAY.
&&
.EQUIPMENT...
AS OF 730 AM EDT FRIDAY ...
THE VISIBILITY SENSOR AT KDAN...DANVILLE REGIONAL AIRPORT...WILL
BE OUT OF SERVICE UNTIL FURTHER NOTICE. A PART HAS BEEN BACK-ORDERED.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/DS
SHORT TERM...RCS
LONG TERM...WERT
AVIATION...AMS/CF
EQUIPMENT...AMS
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
143 AM EDT FRI AUG 29 2014
.SYNOPSIS...
A WEAK COLD FRONT WILL STALL ACROSS NORTH CAROLINA LATE TONIGHT...
THEN HEAD BACK NORTH AGAIN FOR FRIDAY INTO SATURDAY. A STRONGER
UPPER SYSTEM WILL BRING A BETTER THREAT FOR SHOWERS AND STORMS TO
CLOSE OUT THE LABOR DAY WEEKEND.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 1100 PM EDT THURSDAY...
BACKDOOR FRONT CURRENTLY HUNG UP OVER SOUTHSIDE VA AND NW NC...ALONG
A UKF-MWK-MTV-LYH-FVX LINE. DEWPOINTS ALONG AND SOUTH OF THE FRONT
ARE IN THE LOWER 70S. NORTH OF THE FRONT DEWPOINTS WERE IN THE
UPPER 50S TO LOWER 60S. FRONT NOT EXPECTED TO MAKE MUCH PROGRESS
OVERNIGHT...MAY DRIFT TO ALONG THE VA/NC BORDER OR JUST INTO
NORTHERN NC. THERE HAS BEEN AN ONGOING CLUSTER OF SHRA/TSRA NEAR
BUCKINGHAM AND FARMVILLE VCNTY OF THE FRONTAL BOUNDARY...RADAR
ESTIMATING UPWARDS OF AN INCH OF RAIN FALLING OVER PARTS OF
SOUTHERN BUCKINGHAM COUNTY DURING THE EVENING. THE HRRR MODEL
SHOWS A GRADUAL DRIFT OF THIS PRECIP TOWARD I-95 CORRIDOR DURING
THE OVERNIGHT WITH POTENTIAL REDEVELOPMENT OF SHRA VCNTY OF THE
FRONT FROM CHARLOTTE COURT HOUSE EAST DURING THE OVERNIGHT.
ASIDE FOR THE SHOWER THREAT ALONG THE FRONT...NOT MUCH GOING ON
WEATHERWISE. THE NORTHERN/WESTERN CWA...FROM THE NC MTNS INTO THE
NRV OF VA...AND FROM THE THE GREENBRIER VALLEY OF WV EAST ALONG
THE I-64 CORRIDOR INTO CENTRAL VA WILL RESIDE NORTH OF THE FRONT
OVERNIGHT. WITH DEWPOINTS IN THE 50S...TEMPERATURES SHOULD BE
ABOUT 10 DEGREES COOLER THAN FOLKS SOUTH OF THE FRONTAL BOUNDARY
WHERE READINGS WILL BE CLOSER TO 70.
OVERNIGHT...SOME OF THE MODELS...ESP THE NAM...INDICATE INCREASING
LOW LEVEL CLOUD COVER PER DEVELOPMENT OF EASTERLY LOW LEVEL WINDS
VCNTY OF THE FRONT...THE RESULTANT UPSLOPE FLOW INTO THE BLUE
RIDGE RESULTING IN CLOUD DEVELOPMENT LATE TONIGHT. ATTM WILL
CONTINUE TO ADVERTISE SOME STRATUS IN THE MORNING...BUT PREFER TO
KEEP OVERALL SKY CONDITIONS TONED DOWN FROM THE NAM BUT THINK
AREAS OVER THE FOOTHILLS AND PIEDMONT COULD BE MOSTLY CLOUDY IN
THE MORNING. PATCHY FOG WILL FORM IN THE MOUNTAIN VALLEYS LATE
TONIGHT WHERE SKIES SHOULD STAY MOSTLY CLEAR...PARTLY CLOUDY AT
WORST. LOWS TONIGHT WILL BE A LITTLE COOLER IN THE NORTH PER DRIER
AIR WITH READINGS IN THE MID TO UPPER 50S...WHILE TEMPERATURES
WILL BE CLOSER TO THE 65-70 DEGREE RANG IN THE SOUTH.
FRIDAY...FRONT STARTS WORKING BACK NORTH ACROSS US. MODELS ARE
AGREEMENT THAT LIFT AND MOISTURE WILL BE LIMITED OVER US BUT CANNOT
RULE OUT ISOLATED SHRA/TSRA IN THE REGION. BEST LIFT WILL BE ACROSS
THE SW VA MTNS TOWARD TN...SO HAVE 30ISH POPS HERE. ANOTHER AREA IS
OVER THE RALEIGH-DURHAM AREA AND EAST...SO MAY SEE SOME SCATTERED
STORMS TOWARD YANCEYVILLE. SE WINDS WILL BE KEEPING TEMPS FROM
GETTING TOO HIGH...PLUS DEALING WITH POTENTIAL LOW CLOUDS INTO
MORNING OVER THE EAST. HIGHS WILL MAY WORK OUT TO BE HOMOGENEOUS
ACROSS THE ENTIRE CWA OUTSIDE THE HIGHER ELEVATIONS WITH LOWER TO
MID 80S. SE FLOW DOWNSLOPE WARMING MAY INCREASE TEMPS OVER THE MTN
EMPIRE BUT STORMS FIRING UP IN THE AFTERNOON SHOULD PREVENT IT FROM
TOPPING OUT CLOSE TO THE MAV GUIDANCE OF UPPER 80S.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY/...
AS OF 310 PM EDT THURSDAY...
UPPER RIDGE EXPECTED TO SHIFT EAST AS STRONGER UPPER TROUGH MOVES
FROM THE UPPER MIDWEST INTO THE GREAT LAKES. MODELS AGREE THAT A SRN
STREAM UPPER SHORTWAVE WITH ENHANCEMENT IN THE JET WILL STREAK OVER
THE GULF COAST STATES AND ACROSS THE WRN SLOPES OF THE APPALACHIANS
SUNDAY. FOR SATURDAY THOUGH...MAINLY LOOKING WEAK FLOW ALOFT WITH
SOME CONVERGENCE ACROSS THE MTNS PER SSE FLOW. MODELS ARE FAVORING A
BIT OF CONVECTION WITH THE LEE TROUGH IN THE EAST...MAINLY FROM THE
ERN WV PANHANDLE SOUTHEAST TOWARD THE TIDEWATER. THINK THE AIRMASS
WILL BE UNSTABLE AND MOIST ENOUGH TO TRIGGER A FEW STORMS BUT
OVERALL UPPER SUPPORT IS LACKING SO ONLY SEEING ISOLATED COVERAGE
OVER THE MTNS AND NORTH OF A ROANOKE TO DANVILLE LINE. MORE SUN
SATURDAY WILL BRING TEMPS TOWARD 90 OUT EAST WITH MID 80S WEST.
SAT NIGHT...MAIN AXIS OF CONVECTION WILL RUN FROM MS-KY...WITH
LITTLE TO NO CHANCE OF SHOWERS EAST OF THE BLUE RIDGE AFTER FRIDAY
EVENING STORMS WANE. WITH THE UPPER SUPPORT TRACKING CLOSER WILL
HAVE AT LEAST SLIGHT CHANCE INTO THE MTNS LATE.
SUNDAY LOOKS ACTIVE AS THE SHORTWAVE SHIFTS ACROSS KY INTO NRN
WV...WITH STRONG CONVERGENCE AND LIFT. WILL SEE HIGH CHANCE/LIKELY
POPS. LOOKS LIKE CLOUD COVER COULD ARRIVE SOON ENOUGH TO KEEP
INSTABILITY LOWER...BUT ENOUGH UPPER SUPPORT/SHEAR IN THE WEST WHERE
A FEW STORMS COULD PRODUCE GUSTY WINDS. HIGHS SUNDAY WILL RANGE FROM
THE UPPER 70S MTNS TO UPPER 80S SE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 300 PM EDT THURSDAY...
MUCH OF THE LONG TERM PERIOD WILL BE INFLUENCED BY A MEAN UPPER
RIDGE THAT WILL INITIALLY RESIDE ALONG AND OFF THE SOUTHEAST
COAST...WHICH GRADUALLY RETROGRESSES AND EXPANDS WESTWARD INTO THE
GULF COAST STATES BY THE END OF THE FORECAST PERIOD.
SOUTHEASTERN RIDGE WILL INITIALLY BE STRONG ENOUGH TO DEFLECT ANY
NORTHERN STREAM ENERGY AWAY FROM THE BLACKSBURG FORECAST AREA...WITH
MAIN BAROCLINIC ZONE REMAINING FROM THE NORTHERN PLAINS EAST INTO
AND THROUGH THE GREAT LAKES INTO NEW ENGLAND.
HOWEVER...TAP OF TROPICAL MOISTURE RIDING AROUND PERIPHERY OF
SOUTHEASTERN RIDGE LIKELY TO REMAIN OVER/NEAR THE BLACKSBURG
FORECAST AREA THROUGH AT LEAST MONDAY OR MONDAY NIGHT...MAINTAINING
THREAT FOR MAINLY DIURNALLY DRIVEN SCATTERED SHOWERS AND
THUNDERSTORMS...SOME OF WHICH MAY BE ACCOMPANIED BY LOCALLY HEAVY
RAIN CONSIDERING RELATIVELY HIGH PRECIPITABLE WATER VALUES EXPECTED
OVER THE AREA.
GRADUAL RETROGRESSION OF UPPER RIDGE INTO NORTHERN GULF COAST REGION
DURING THE MIDWEEK PERIOD SHOULD BE SUFFICIENT TO ALLOW WINDS ALOFT
TO VEER SUCH THAT INFLUENCE OF TROPICAL MOISTURE TAP GRADUALLY
WANES...ONLY TO BE REPLACED BY MORE AGGRESSIVE SOUTHWARD INTRUSION
OF NORTHERN STREAM ENERGY AND ASSOCIATED SCATTERED SHOWERS/STORMS IN
ADVANCE OF AN ACCOMPANYING DECAYING COOL FRONT INTO THE MID
APPALACHIAN AND MID ATLANTIC REGION IN TUESDAY-WEDNESDAY TIMEFRAME.
PUSH OF POST-FRONTAL SLIGHTLY DRIER AIR MAY BE STRONG ENOUGH TO
REDUCE THREAT FOR PRECIPITATION ACROSS AREAS NORTH OF INTERSTATE 64
BY THURSDAY...BUT WITH AT LEAST A CHANCE THREAT FOR SHOWERS/STORMS
REDEVELOPING BY AFTERNOON ACROSS THE SOUTHWESTERN MOUNTAINS CLOSER
TO DECAYING FRONTAL BOUNDARY AND PROXIMITY TO HIGHER THETA-E AIR.
PLENTY OF CLOUD COVER AND DEWPOINTS PRIMARILY IN THE 60S SHOULD
ENSURE THAT TEMPERATURES REMAIN CLOSE TO SEASONAL AVERAGES...MAINLY
MID 70S TO LOWER 80S ACROSS THE HIGHER ELEVATIONS BY DAY WITH UPPER
80S ACROSS THE PIEDMONT...WITH MAINLY 60S AT NIGHT. INTRUSION OF
SLIGHTLY COOLER/DRIER POST-FRONTAL AIR FROM THE NORTHEAST MAY ALLOW
TEMPERATURES TO BE A FEW DEGREES COOLER ON THURSDAY.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 135 AM EDT FRIDAY...
A STATIONARY FRONT EXTENDED FROM AROUND NORFOLK TO JUST SOUTH OF
KDAN TO NORTHEAST TENNESSEE. EAST WINDS NORTH OF THE BOUNDARY WERE
EXPECTED TO BRING A STRATUS LAYER IN FROM THE COAST. LOW
CONFIDENCE AT THIS TIME THAT KLYH OR KDAN WILL DROP TO MVFR
CEILINGS OR LOWER BEFORE 12Z/8AM.
THE SKY WAS CLEAR AT KLWB AND WITH A SMALL TEMPERATURE/DEW POINT
DEPRESSION...EXPECTING FOG WILL DEVELOP EARLY THIS MORNING. MEDIUM CONFIDENCE
OF AT LEAST IFR VISIBILITY AT THIS AIRPORT AFTER 09Z/5AM.
THERE WILL BE LITTLE CHANGE IN THE WEATHER PATTERN TODAY AND
TONIGHT. THE BEST PROBABILITY OF SHOWERS AND THUNDERSTORMS THIS
AFTERNOON AND EVENING WILL REMAIN SOUTH OF THE FORECAST AREA. NO
MENTION OF SHOWERS OR THUNDERSTORMS NEEDED IN THE TAFS AT THIS
TIME.
EXTENDED DISCUSSION...
WIDELY SCATTERED SHOWERS AND THUNDERSTORMS WILL AFFECT THE REGION
AGAIN ON SATURDAY...MAINLY DURING THE LATE AFTERNOON AND EARLY
EVENING. SHOULD ONE OF THESE STORMS DEVELOP NEAR A TAF LOCATION IT
COULD RESULT IN A BRIEF PERIOD OF SUB VFR CONDITIONS.
AN AREA OF LOW PRESSURE IS FORECAST TO MOVE THROUGH THE GREAT
LAKES SATURDAY NIGHT AND SUNDAY...THE ASSOCIATED COLD FRONT
TRAILING SOUTH AND MOVING ACROSS THE OHIO/TN VALLEYS. SHOWERS AND
THUNDERSTORMS WILL LIKELY BE ASSOCIATED WITH THIS FRONT...THIS
ACTIVITY SPREADING EAST INTO THE CENTRAL APPALACHIANS SUNDAY AND
MONDAY. SHOWER COVERAGE SUNDAY/MONDAY IS EXPECTED TO BE MORE
WIDESPREAD AS COMPARED TO FRIDAY AND SATURDAY.
&&
.EQUIPMENT...
AS OF 100 PM EDT THURSDAY ...
THE VISIBILITY SENSOR AT KDAN...DANVILLE REGIONAL AIRPORT...REMAINS
OUT OF SERVICE. A PART HAS BEEN ORDERED. REPAIRS WILL BE DONE THIS FRIDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS/WP
NEAR TERM...PM/WP
SHORT TERM...WP
LONG TERM...WERT
AVIATION...AMS/CF
EQUIPMENT...AMS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1256 PM CDT FRI AUG 29 2014
.UPDATE...
ISSUED AT 1105 AM CDT FRI AUG 29 2014
RADAR IS PRETTY QUITE AROUND THE FORECAST AREA WITH WEATHER
MAINLY FURTHER WEST. LATEST VISIBLE IMAGERY SHOWING A GENERAL
CLEARING AND DEEPER MIXING TREND OVER THE SOUTHERN FORECAST AREA.
LOWER STRATOCUMULUS IS IN PLACE UNDER THE CAPPING INVERSION OVER
NORTHEAST IOWA INTO CENTRAL WI AND THIS IS ERODING FROM THE SOUTH
AS DEEPER MIXING OCCURS /EVIDENCED BY MORE GUSTING IN THE
OBSERVATIONS ALONG HIGHWAY 20 IN IA AND INTO NORTHCENTRAL IA/.
A BIT FURTHER NORTH ALONG THE I-94 CORRIDOR LIES SOME CONVERGENT FLOW
ALONG THE WARM FRONT WITH A WIND SHIFT FROM SE TO S/SW. SOME FOG
AND LOWER VISIBILITY IS SEEN NORTH OF I-94 TOO IN CLASSIC WARM
FRONT SCENARIO.
EXPECT THE NORTHWARD TREND TO CONTINUE OF THE WARM FRONT WITH SOME
SMALL SHOWERS POSSIBLE ALONG/NORTH OF THE WARM FRONT THROUGH MID
DAY UNTIL S/SWRLY WINDS TAKE HOLD. THIS SHOULD PROVIDE A DRIER
EARLY AFTERNOON AT LEAST. AREA SHOULD THEN BE IN A DESTABILIZING
WARM SECTOR WITH WEAK CAPPING AFTER 3 PM. THE DIFFICULT ISSUE TO
TACKLE RIGHT NOW IS WHAT TYPE OF FORCING WILL BE PRESENT FOR THE
HIGH STORM CHANCES THE FORECAST HAD/HAS FROM 3-6 PM. BELIEVE THE
MAIN FORCING FOR TSRA WILL ARRIVE VIA CURRENT KANSAS SHORTWAVE
TROUGH LIFTING N/NE INTO MN TONIGHT. WHILE THE NORTHERN STREAM
FRONT WILL SHIFT SEWRD /NOW FROM ROUGHLY MSP-DLH/ TO PROVIDE
CONVERGENCE...IT STILL REMAINS NORTHWEST UNTIL EVENING FROM
CONSENSUS SHORT TERM MODEL GUIDANCE. THIS SEEMS VERY REASONABLE
BASED ON CURRENT OBSERVATIONAL DATA. SO, WARM SECTOR SOUTHERLY
FLOW IS NOT VERY CONVERGENT FOR STORM INITIATION THIS AFTERNOON
EXCEPT MAYBE IN THE VERY FAR WEST FORECAST AREA. ALL OF THE
TRENDS FOR WEATHER ARE VERY LATE AFTERNOON WEST OF MISS RIVER AND
IN THE EVENING EAST OF THE RIVER.
SO...HAVE DRIED OUT THE FORECAST THROUGH MID AFTERNOON AREA-WIDE.
BELIEVE THE TREND WILL BE TO CONCENTRATE ON LOW MOVING NORTHWARD
FROM KS...AND THIS WOULD BE TO DELAY THE RAIN/STORM ONSET
/FURTHER/ INTO LATER TODAY AND MAINLY THIS EVENING. SO...THINKING
THAT ANOTHER UPDATE TO DELAY OUR CURRENT FORECAST MAY BE NEEDED IN
EARLY AFTERNOON.
SEVERE STORM CHANCES ARE STILL AROUND...IF NOT GROWING WITH
WARM SECTOR DESTABILIZING...WEAK CAP BY EVENING...AND FORCING
MOVING IN. MLCAPES IN THE EARLY EVENING SEEM LIKE THEY SHOULD BE
IN THE 1000-1500 J/KG RANGE. 0-3KM BULK SHEAR IN THE 20-25KT RANGE
NOT SUPER IMPRESSIVE...SEEMS TO PROVIDE ISOLATED WIND THREATS VIA
BOWING SEGMENTS ORIENTED NW-SE. THESE MAY HAVE LIMITED LIFE
CYCLES AND MAKE LEAD TIME TOUGH FOR ANY WARNINGS. WITH MORE
FORCING/DYNAMICS WEST OF MISS RIVER INTO KEAU AREA...THAT SEEMS TO
BE THE PREFERRED AREA FOR THIS ISOLATED ACTIVITY. HEAVY RAIN IS
ALSO A THREAT AND STORM TRAINING COULD OCCUR IN THAT SAME
AREA...BUT THEN IT SHOULD TURN PROGRESSIVE MID-EVENING AND INTO WI.
AS THE WEATHER SHIFTS EASTWARD...THREATS DIMINISH TO LIGHTNING
WITH PROGRESSIVE NATURE TO RAIN AND DIMINISHING INSTABILITY.
MAYBE THE NUMBER ONE THREAT IS LIGHTNING FOR FRIDAY NIGHT FOOTBALL
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 309 AM CDT FRI AUG 29 2014
THE MAIN FORECAST CONCERN IS WITH THE RAIN CHANCES THROUGH THE
PERIOD.
LOCAL AND REGIONAL RADARS SHOWING AN AREA OF SHOWERS AND STORMS
ACROSS SOUTHERN MINNESOTA INTO CENTRAL IOWA. THIS ACTIVITY HAS
BEEN MOVING NORTHEAST AND THE 29.00Z HRRR SEEMED TO HAVE A DECENT
HANDLE ON THIS. IT SUGGESTS THAT IT WILL CONTINUE TO MOVE
NORTHEAST INTO THE AREA AND MAY SHOW A DIMINISHING TREND AS IT
OUTRUNS THE AVAILABLE CAPE. THE 29.06Z RAP ANALYSIS SUGGESTED
THERE WAS AROUND 250 J/KG OF MU CAPE OVER THE WESTERN SECTIONS
WITH THIS DROPPING TO NEAR ZERO OVER WESTERN AND CENTRAL
WISCONSIN. WHILE THE THUNDER MAY DIMINISH AS THE SYSTEM CONTINUES
TO WORK NORTHEAST...THE AREAL COVERAGE MAY NOT CHANGE MUCH AS THE
29.05Z RAP INDICATES THE ACTIVITY IS ON THE NOSE OF THE 850 MB LOW
LEVEL JET AND THIS MAINTAINS ITS INTENSITY AS IT LIFTS NORTHEAST
THROUGH THE AREA FOR THE REMAINDER OF THE NIGHT. PLAN TO START THE
DAY WITH AT LEAST A 70 PERCENT CHANCE OF RAIN OVER MUCH OF CENTRAL
INTO PARTS OF WESTERN WISCONSIN AND THEN DIMINISH THESE DOWN TO 30
TO 50 PERCENT BY LATE MORNING AS THE AREA GETS IN BETWEEN
SYSTEMS. BOTH THE HRRR AND 29.00Z HI-RES ARW SUGGEST MOST IF NOT
ALL OF THE AREA COULD BE RAIN FREE FOR A SHORT WHILE LATE THIS
MORNING.
THIS DRY PERIOD WILL NOT LAST VERY LONG AS THE MEAN LONG WAVE
TROUGH WILL START TO APPROACH FROM THE WEST IN THE AFTERNOON WITH
A STRONG SHORT WAVE TROUGH EMBEDDED IN THE FLOW. THIS IS EXPECTED
TO PRODUCE WEAK TO MODERATE PV ADVECTION IN THE 500-300 MB LAYER
DURING THE AFTERNOON AND EVENING. THE 29.00Z NAM SUGGEST THERE
COULD ALSO BE SOME COUPLED JET DYNAMICS FROM THE RIGHT ENTRANCE
REGION OF THE MAIN JET CORE ACROSS THE NORTHERN GREAT LAKES INTO
SOUTHEAST CANADA AND FROM THE LEFT EXIT REGION OF A SECONDARY JET
ROUNDING THE BASE OF THE LONG WAVE TROUGH. THE CAPE WILL INCREASE
IN THE AFTERNOON...ESPECIALLY ACROSS THE SOUTHEAST TWO-THIRDS OF
THE FORECAST AREA...WHERE THE NAM INDICATES THE POTENTIAL OF
1500-2500 J/KG OF ML CAPE. THIS MAY BE A LITTLE ON THE HIGH SIDE
AS IT IS SHOWING WIDESPREAD LOWER 70S DEW POINTS WHEN THESE MAY
ONLY BE IN THE UPPER 60S TO AROUND 70. NONE THE LESS...EXPECT TO
SEE AN INCREASE IN THE ACTIVITY DURING THE AFTERNOON INTO THE
EVENING AND WILL PUSH THE RAIN CHANCES BACK UP INTO THE 70 TO 80
PERCENT RANGE BY EVENING WHEN THE FORCING IS THE BEST. THE
ACTIVITY SHOULD START TO MOVE OUT OF THE AREA LATE TONIGHT INTO
SATURDAY MORNING AND THEN END DURING THE AFTERNOON AS THE LONG
WAVE TROUGH MOVES PAST THE AREA. IF THE CAPE ADVERTISED BY THE
MODELS CAN BE REALIZED...THEN THERE COULD SOME POTENTIAL FOR
SEVERE STORMS. THE 0-3KM BULK SHEAR SHOULD BE IN THE 30 TO 40 KNOT
RANGE WHICH WOULD BE ENOUGH TO SUPPORT SOME STRONG WINDS.
ONCE THE RAIN ENDS SATURDAY...IT APPEARS THAT SOME WEAK RIDGING
WILL BUILD OVER THE AREA FOR A DRY SATURDAY NIGHT. THIS RIDGING
WILL THEN QUICKLY BE PUSHED OUT OF THE AREA SUNDAY AS YET ANOTHER
LONG WAVE TROUGH STARTS TO COME IN FROM THE NORTHERN ROCKIES.
HOWEVER...IT APPEARS THE TIMING OF THIS SYSTEM WOULD BE SUCH THAT
THERE WILL ONLY BE A SMALL CHANCE FOR SOME ADDITIONAL RAINS ACROSS
THE FAR WESTERN SECTIONS SUNDAY AFTERNOON.
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 309 AM CDT FRI AUG 29 2014
PRETTY DECENT AGREEMENT BETWEEN THE MEDIUM RANGE MODELS THAT THIS
NEXT SYSTEM WILL MOVE ACROSS THE UPPER MIDWEST SUNDAY NIGHT AND
MONDAY. THE 29.00Z ECMWF AND GFS BOTH INDICATE THE EMBEDDED SHORT
WAVE TROUGH COULD PRODUCE MODERATE TO STRONG PV ADVECTION IN THE
500-300 MB LAYER WHILE THE 29.00Z GEM SHOWS WEAK TO MODERATE PV
ADVECTION. ALL THREE MODELS DO SHOW THE COLD FRONT WITH THIS
SYSTEM PASSING THROUGH LATE SUNDAY NIGHT INTO MONDAY MORNING WITH
A SOLID SHIELD OF RAIN ALONG AND AHEAD OF IT. WILL SHOW 60 TO 80
PERCENT RAIN CHANCES SUNDAY NIGHT FROM EAST TO WEST AND 30 TO 60
PERCENT CHANCES MONDAY. HOWEVER...IF THE TIMING OF THE SYSTEM
REMAINS THE SAME...THE MONDAY RAIN CHANCES MAY HAVE TO BE
INCREASED...ESPECIALLY IN THE MORNING. THE TIMING OF THE FRONT IS
NOT IDEAL FOR SEVERE CHANCES...BUT THE GFS DOES SHOW 500-1000 J/KG
OF ML CAPE PERSISTING SUNDAY NIGHT AHEAD OF THE FRONT WITH AROUND
40 KNOTS OF 0-6KM SHEAR. THIS WOULD BE SUFFICIENT TO SUPPORT SOME
STRONGER STORMS THAT COULD PRODUCE SOME STRONG WINDS. ANOTHER COLD
FRONT LOOKS TO MOVE THROUGH LATE IN THE PERIOD FOR ADDITIONAL RAIN
CHANCES WEDNESDAY NIGHT INTO THURSDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1256 PM CDT FRI AUG 29 2014
INSTABILITY IS GROWING ACROSS THE TAF SITES THIS AFTERNOON AND
LATER IN THE DAY AND THROUGH THE EVENING...THUNDERSTORMS AND RAIN
WILL DEVELOP. TRIED TO CONCENTRATE THE TSRA CHANCES INTO A 3 HOUR
WINDOW THIS EVENING. HEAVIER RAINFALL RATES WILL MEAN MORE LIKELY
IFR CONDITIONS FROM ANY TSRA...ESPECIALLY WITH INSTABILITY
BUILDING AND THE AIR MASS CONTAINING RICH MOISTURE.
THERE WILL BE A VERY MOIST BOUNDARY LAYER BY SUNRISE WITH LIGHT
WINDS. IT SEEMS THE PROBABILITIES FOR LIFR CIGS ARE INCREASING
THROUGH THE OVERNIGHT SO CONTINUED THE TREND OF LOW CIGS AND FOG
SATURDAY MORNING.
&&
.HYDROLOGY...
ISSUED AT 309 AM CDT FRI AUG 29 2014
PLAN TO CONTINUE WITH THE HYDROLOGIC OUTLOOK THIS MORNING. NOT
OVERLY CONCERNED ABOUT ANY FLOODING THREATS AS THE RAIN THURSDAY
DID NOT TURN OUT TO BE AS HEAVY AS EXPECTED AND THE CURRENT
FORECAST IS FOR ANOTHER 1 TO 1.5 INCHES THROUGH SATURDAY. WILL
LIKELY BE SOME LOCALLY HIGHER AMOUNTS THOUGH AS THE CONDITIONS ARE
STILL IN PLACE FOR SOME HEAVY RAIN TO OCCUR. PRECIPITABLE WATERS
WILL REMAIN IN THE 1.5 TO 2 INCH RANGE WITH WARM CLOUD DEPTHS OF
3.5 TO 4 KM WHICH WILL HELP TO MAKE THE CONVECTION EFFICIENT RAIN
PRODUCERS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...BAUMGARDT
SHORT TERM...04
LONG TERM...04
AVIATION...BAUMGARDT
HYDROLOGY...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1110 AM CDT FRI AUG 29 2014
.UPDATE...
ISSUED AT 1105 AM CDT FRI AUG 29 2014
RADAR IS PRETTY QUITE AROUND THE FORECAST AREA WITH WEATHER
MAINLY FURTHER WEST. LATEST VISIBLE IMAGERY SHOWING A GENERAL
CLEARING AND DEEPER MIXING TREND OVER THE SOUTHERN FORECAST AREA.
LOWER STRATOCUMULUS IS IN PLACE UNDER THE CAPPING INVERSION OVER
NORTHEAST IOWA INTO CENTRAL WI AND THIS IS ERODING FROM THE SOUTH
AS DEEPER MIXING OCCURS /EVIDENCED BY MORE GUSTING IN THE
OBSERVATIONS ALONG HIGHWAY 20 IN IA AND INTO NORTHCENTRAL IA/.
A BIT FURTHER NORTH ALONG THE I-94 CORRIDOR LIES SOME CONVERGENT FLOW
ALONG THE WARM FRONT WITH A WIND SHIFT FROM SE TO S/SW. SOME FOG
AND LOWER VISIBILITY IS SEEN NORTH OF I-94 TOO IN CLASSIC WARM
FRONT SCENARIO.
EXPECT THE NORTHWARD TREND TO CONTINUE OF THE WARM FRONT WITH SOME
SMALL SHOWERS POSSIBLE ALONG/NORTH OF THE WARM FRONT THROUGH MID
DAY UNTIL S/SWRLY WINDS TAKE HOLD. THIS SHOULD PROVIDE A DRIER
EARLY AFTERNOON AT LEAST. AREA SHOULD THEN BE IN A DESTABILIZING
WARM SECTOR WITH WEAK CAPPING AFTER 3 PM. THE DIFFICULT ISSUE TO
TACKLE RIGHT NOW IS WHAT TYPE OF FORCING WILL BE PRESENT FOR THE
HIGH STORM CHANCES THE FORECAST HAD/HAS FROM 3-6 PM. BELIEVE THE
MAIN FORCING FOR TSRA WILL ARRIVE VIA CURRENT KANSAS SHORTWAVE
TROUGH LIFTING N/NE INTO MN TONIGHT. WHILE THE NORTHERN STREAM
FRONT WILL SHIFT SEWRD /NOW FROM ROUGHLY MSP-DLH/ TO PROVIDE
CONVERGENCE...IT STILL REMAINS NORTHWEST UNTIL EVENING FROM
CONSENSUS SHORT TERM MODEL GUIDANCE. THIS SEEMS VERY REASONABLE
BASED ON CURRENT OBSERVATIONAL DATA. SO, WARM SECTOR SOUTHERLY
FLOW IS NOT VERY CONVERGENT FOR STORM INITIATION THIS AFTERNOON
EXCEPT MAYBE IN THE VERY FAR WEST FORECAST AREA. ALL OF THE
TRENDS FOR WEATHER ARE VERY LATE AFTERNOON WEST OF MISS RIVER AND
IN THE EVENING EAST OF THE RIVER.
SO...HAVE DRIED OUT THE FORECAST THROUGH MID AFTERNOON AREA-WIDE.
BELIEVE THE TREND WILL BE TO CONCENTRATE ON LOW MOVING NORTHWARD
FROM KS...AND THIS WOULD BE TO DELAY THE RAIN/STORM ONSET
/FURTHER/ INTO LATER TODAY AND MAINLY THIS EVENING. SO...THINKING
THAT ANOTHER UPDATE TO DELAY OUR CURRENT FORECAST MAY BE NEEDED IN
EARLY AFTERNOON.
SEVERE STORM CHANCES ARE STILL AROUND...IF NOT GROWING WITH
WARM SECTOR DESTABILIZING...WEAK CAP BY EVENING...AND FORCING
MOVING IN. MLCAPES IN THE EARLY EVENING SEEM LIKE THEY SHOULD BE
IN THE 1000-1500 J/KG RANGE. 0-3KM BULK SHEAR IN THE 20-25KT RANGE
NOT SUPER IMPRESSIVE...SEEMS TO PROVIDE ISOLATED WIND THREATS VIA
BOWING SEGMENTS ORIENTED NW-SE. THESE MAY HAVE LIMITED LIFE
CYCLES AND MAKE LEAD TIME TOUGH FOR ANY WARNINGS. WITH MORE
FORCING/DYNAMICS WEST OF MISS RIVER INTO KEAU AREA...THAT SEEMS TO
BE THE PREFERRED AREA FOR THIS ISOLATED ACTIVITY. HEAVY RAIN IS
ALSO A THREAT AND STORM TRAINING COULD OCCUR IN THAT SAME
AREA...BUT THEN IT SHOULD TURN PROGRESSIVE MID-EVENING AND INTO WI.
AS THE WEATHER SHIFTS EASTWARD...THREATS DIMINISH TO LIGHTNING
WITH PROGRESSIVE NATURE TO RAIN AND DIMINISHING INSTABILITY.
MAYBE THE NUMBER ONE THREAT IS LIGHTNING FOR FRIDAY NIGHT FOOTBALL
GAMES. WILL TRY TO PROVIDE MORE UPDATES ON TIMING TODAY.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 309 AM CDT FRI AUG 29 2014
THE MAIN FORECAST CONCERN IS WITH THE RAIN CHANCES THROUGH THE
PERIOD.
LOCAL AND REGIONAL RADARS SHOWING AN AREA OF SHOWERS AND STORMS
ACROSS SOUTHERN MINNESOTA INTO CENTRAL IOWA. THIS ACTIVITY HAS
BEEN MOVING NORTHEAST AND THE 29.00Z HRRR SEEMED TO HAVE A DECENT
HANDLE ON THIS. IT SUGGESTS THAT IT WILL CONTINUE TO MOVE
NORTHEAST INTO THE AREA AND MAY SHOW A DIMINISHING TREND AS IT
OUTRUNS THE AVAILABLE CAPE. THE 29.06Z RAP ANALYSIS SUGGESTED
THERE WAS AROUND 250 J/KG OF MU CAPE OVER THE WESTERN SECTIONS
WITH THIS DROPPING TO NEAR ZERO OVER WESTERN AND CENTRAL
WISCONSIN. WHILE THE THUNDER MAY DIMINISH AS THE SYSTEM CONTINUES
TO WORK NORTHEAST...THE AREAL COVERAGE MAY NOT CHANGE MUCH AS THE
29.05Z RAP INDICATES THE ACTIVITY IS ON THE NOSE OF THE 850 MB LOW
LEVEL JET AND THIS MAINTAINS ITS INTENSITY AS IT LIFTS NORTHEAST
THROUGH THE AREA FOR THE REMAINDER OF THE NIGHT. PLAN TO START THE
DAY WITH AT LEAST A 70 PERCENT CHANCE OF RAIN OVER MUCH OF CENTRAL
INTO PARTS OF WESTERN WISCONSIN AND THEN DIMINISH THESE DOWN TO 30
TO 50 PERCENT BY LATE MORNING AS THE AREA GETS IN BETWEEN
SYSTEMS. BOTH THE HRRR AND 29.00Z HI-RES ARW SUGGEST MOST IF NOT
ALL OF THE AREA COULD BE RAIN FREE FOR A SHORT WHILE LATE THIS
MORNING.
THIS DRY PERIOD WILL NOT LAST VERY LONG AS THE MEAN LONG WAVE
TROUGH WILL START TO APPROACH FROM THE WEST IN THE AFTERNOON WITH
A STRONG SHORT WAVE TROUGH EMBEDDED IN THE FLOW. THIS IS EXPECTED
TO PRODUCE WEAK TO MODERATE PV ADVECTION IN THE 500-300 MB LAYER
DURING THE AFTERNOON AND EVENING. THE 29.00Z NAM SUGGEST THERE
COULD ALSO BE SOME COUPLED JET DYNAMICS FROM THE RIGHT ENTRANCE
REGION OF THE MAIN JET CORE ACROSS THE NORTHERN GREAT LAKES INTO
SOUTHEAST CANADA AND FROM THE LEFT EXIT REGION OF A SECONDARY JET
ROUNDING THE BASE OF THE LONG WAVE TROUGH. THE CAPE WILL INCREASE
IN THE AFTERNOON...ESPECIALLY ACROSS THE SOUTHEAST TWO-THIRDS OF
THE FORECAST AREA...WHERE THE NAM INDICATES THE POTENTIAL OF
1500-2500 J/KG OF ML CAPE. THIS MAY BE A LITTLE ON THE HIGH SIDE
AS IT IS SHOWING WIDESPREAD LOWER 70S DEW POINTS WHEN THESE MAY
ONLY BE IN THE UPPER 60S TO AROUND 70. NONE THE LESS...EXPECT TO
SEE AN INCREASE IN THE ACTIVITY DURING THE AFTERNOON INTO THE
EVENING AND WILL PUSH THE RAIN CHANCES BACK UP INTO THE 70 TO 80
PERCENT RANGE BY EVENING WHEN THE FORCING IS THE BEST. THE
ACTIVITY SHOULD START TO MOVE OUT OF THE AREA LATE TONIGHT INTO
SATURDAY MORNING AND THEN END DURING THE AFTERNOON AS THE LONG
WAVE TROUGH MOVES PAST THE AREA. IF THE CAPE ADVERTISED BY THE
MODELS CAN BE REALIZED...THEN THERE COULD SOME POTENTIAL FOR
SEVERE STORMS. THE 0-3KM BULK SHEAR SHOULD BE IN THE 30 TO 40 KNOT
RANGE WHICH WOULD BE ENOUGH TO SUPPORT SOME STRONG WINDS.
ONCE THE RAIN ENDS SATURDAY...IT APPEARS THAT SOME WEAK RIDGING
WILL BUILD OVER THE AREA FOR A DRY SATURDAY NIGHT. THIS RIDGING
WILL THEN QUICKLY BE PUSHED OUT OF THE AREA SUNDAY AS YET ANOTHER
LONG WAVE TROUGH STARTS TO COME IN FROM THE NORTHERN ROCKIES.
HOWEVER...IT APPEARS THE TIMING OF THIS SYSTEM WOULD BE SUCH THAT
THERE WILL ONLY BE A SMALL CHANCE FOR SOME ADDITIONAL RAINS ACROSS
THE FAR WESTERN SECTIONS SUNDAY AFTERNOON.
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 309 AM CDT FRI AUG 29 2014
PRETTY DECENT AGREEMENT BETWEEN THE MEDIUM RANGE MODELS THAT THIS
NEXT SYSTEM WILL MOVE ACROSS THE UPPER MIDWEST SUNDAY NIGHT AND
MONDAY. THE 29.00Z ECMWF AND GFS BOTH INDICATE THE EMBEDDED SHORT
WAVE TROUGH COULD PRODUCE MODERATE TO STRONG PV ADVECTION IN THE
500-300 MB LAYER WHILE THE 29.00Z GEM SHOWS WEAK TO MODERATE PV
ADVECTION. ALL THREE MODELS DO SHOW THE COLD FRONT WITH THIS
SYSTEM PASSING THROUGH LATE SUNDAY NIGHT INTO MONDAY MORNING WITH
A SOLID SHIELD OF RAIN ALONG AND AHEAD OF IT. WILL SHOW 60 TO 80
PERCENT RAIN CHANCES SUNDAY NIGHT FROM EAST TO WEST AND 30 TO 60
PERCENT CHANCES MONDAY. HOWEVER...IF THE TIMING OF THE SYSTEM
REMAINS THE SAME...THE MONDAY RAIN CHANCES MAY HAVE TO BE
INCREASED...ESPECIALLY IN THE MORNING. THE TIMING OF THE FRONT IS
NOT IDEAL FOR SEVERE CHANCES...BUT THE GFS DOES SHOW 500-1000 J/KG
OF ML CAPE PERSISTING SUNDAY NIGHT AHEAD OF THE FRONT WITH AROUND
40 KNOTS OF 0-6KM SHEAR. THIS WOULD BE SUFFICIENT TO SUPPORT SOME
STRONGER STORMS THAT COULD PRODUCE SOME STRONG WINDS. ANOTHER COLD
FRONT LOOKS TO MOVE THROUGH LATE IN THE PERIOD FOR ADDITIONAL RAIN
CHANCES WEDNESDAY NIGHT INTO THURSDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 700 AM CDT FRI AUG 29 2014
RAIN AREA SHIFTING NORTHWARD SO FEEL ANY RAIN WILL BE OUT OF THE
AIRFIELDS BY MID-MORNING. AS UPPER SYSTEM CONTINUES TO MOVE TOWARD
THE REGION...LOOKING LIKE THE DRY SLOT WILL PROVIDE FOR SOME
PARTIAL SUNSHINE FOR A TIME LATE THIS MORNING. BUT THAT WILL ONLY
HELP TO DESTABLIZE THE ATMOSPHERE...LEADING TO MORE CONVECTIVE
DEVELOPMENT. VARIOUS MESOSCALE MODEL SOLUTIONS SUGGEST SCATTERED
CONVECTION DEVELOPS IN THE WARM AND MOIST AIR...WITH A MORE
FOCUSED BAND OF STORMS WHERE SOME FRONTAL CONVERGENCE LOOKS TO
EXIST. THIS LOOKS TO BE PRIMARILY NEAR THE KRST AIRFIELD. EITHER
WAY...BOTH TAF FORECASTS WILL INCLUDE A TSRA RISK FOR SEVERAL
HOURS FROM THE AFTERNOON INTO EVENING. ONCE THE RAIN MOVES THROUGH
BY MIDNIGHT...LOW STRATUS AND FOG LOOK TO BE A GOOD BET...WITH
LIFR CONDITIONS ANTICIPATED.
&&
.HYDROLOGY...
ISSUED AT 309 AM CDT FRI AUG 29 2014
PLAN TO CONTINUE WITH THE HYDROLOGIC OUTLOOK THIS MORNING. NOT
OVERLY CONCERNED ABOUT ANY FLOODING THREATS AS THE RAIN THURSDAY
DID NOT TURN OUT TO BE AS HEAVY AS EXPECTED AND THE CURRENT
FORECAST IS FOR ANOTHER 1 TO 1.5 INCHES THROUGH SATURDAY. WILL
LIKELY BE SOME LOCALLY HIGHER AMOUNTS THOUGH AS THE CONDITIONS ARE
STILL IN PLACE FOR SOME HEAVY RAIN TO OCCUR. PRECIPITABLE WATERS
WILL REMAIN IN THE 1.5 TO 2 INCH RANGE WITH WARM CLOUD DEPTHS OF
3.5 TO 4 KM WHICH WILL HELP TO MAKE THE CONVECTION EFFICIENT RAIN
PRODUCERS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...BAUMGARDT
SHORT TERM...04
LONG TERM...04
AVIATION...MW
HYDROLOGY...04
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1022 AM CDT FRI AUG 29 2014
.UPDATE...BOOSTED POPS EARLIER IN THE SE TO ACCOUNT FOR CORRIDOR
OF SHRA/TSRA WRAPPING NE ON PERIPHERY OF SE US UPPER RIDGE. ALSO
LOWERED POPS IN THE WRN CWA WHERE MORE STABLE AIRMASS RESIDES WITH
LINGERING STRATUS. APPEARS UPPER DYNAMICS ASSOCIATED PLAINS MID
LEVEL TROUGH AXIS WILL HOLD OFF ON IMPACTING CWA UNTIL TONIGHT. SO
LEANING MORE TOWARDS LATEST HRRR VERSUS THE MORE AGGRESSIVE 00Z
RUNS OF ARW AND NMM. SURFACE WARM FRONT HAS LIFTED NORTH OUT OF
CWA. WITH SOUTH WINDS AS FAR NORTH AS KSBM.
PC
&&
.AVIATION/18Z TAFS/...CORRIDOR OF ISOLD/SCT CONVECTION WRAPPING
INTO SE WI WILL POTENTIALLY AFFECT THE 3 EASTERN TAF SITES THIS
AFTN. MEANWHILE KMSN IS NEAR EASTERN EDGE OF MVFR STRATUS FIELD.
EXPECT THIS TO SCATTER A BIT AND LIFT A BIT BUT LIKELY REMAIN AT
MVFR LEVELS. EXPECT CONVECTION TO BECOME MORE WIDESPREAD TONIGHT
INTO AT LEAST SATURDAY MORNING AS MID LEVEL TROUGH AXIS AND
SURFACE LOW MOVE INTO WI.
PC
&&
.PREV DISCUSSION... /ISSUED 518 AM CDT FRI AUG 29 2014/
TODAY AND TONIGHT...FORECAST CONFIDENCE MEDIUM.
INFLUENCE OF DRY SOUTHEAST FLOW AROUND WESTERN FLANK OF DEPARTING
HIGH PRESSURE EVIDENT IN TIGHT SURFACE DEW POINT GRADIENT THAT
REMAINS ALONG IL/WI BORDER AND THE MS RIVER VALLEY.
SHOWERS ACROSS CENTRAL/NE WI IN REGION OF 850 MB FRONTOGENETIC
RESPONSE TO 20-30 KT WINDS ACROSS EAST-WEST 850 MB BAROCLINIC ZONE
BISECTING THE STATE.
MCV-DRIVEN POCKET OF SHOWERS/THUNDERSTORMS IN NORTHEAST IOWA IS
WEAKENING AS IT LIFTS NE TOWARD SW WI AND INTO THE DRIER...MORE
STABLE AIR...WITH THE MCV SHEARING OUT/ WEAKENING AS IT MOVES INTO
THE MEAN RIDGE POSITION. HOWEVER MOISTURE TRANSPORT INTO STATE ON 30
KT 850 MB WINDS ALONG WITH ADDITIONAL FORCING FOR ASCENT FROM UPPER
LEVEL DIFFLUENCE/DIVERGENCE WILL BE ENOUGH TO SUPPORT THE SHOWERS
ACROSS THE NORTHWEST HALF OF THE FORECAST AREA THIS MORNING...WITH
SOME SCATTERED SHOWERS IN THE SOUTHEAST. A FEW RUMBLES OF THUNDER
ARE POSSIBLE.
MODELS INDICATE A BREAK IN THE PCPN LATE THIS MORNING INTO THIS
AFTERNOON. UPPER RIDGING SLOWLY MOVING EAST WITH APPROACHING TROUGH
OMEGA INCREASES AS LLJ STRENGTHENS LATE THIS AFTERNOON AND EVENING
AS MAIN 500 MB TROUGH MOVES INTO WRN WI BY 12Z SAT.
NORTHWEST HALF OF FORECAST AREA IN FAVORABLE AREA FOR HEAVY RAIN
TONIGHT AS CAPE IS TALL AND SKINNY WITH CORFIDI VECTORS HOVERING
AROUND 10KTS...WITH PRECIP WATER VALUES RISING FROM 1.6 TO 2 INCHES.
WPC HAS LOCATIONS NORTHWEST OF A PORT WASHINGTON...FORT ATKINSON TO
MONROE LINE ARE IN A SLIGHT RISK FOR RAINFALL TO EXCEED FLASH FLOOD
GUIDANCE.
HOWEVER...WITH PREVIOUS 24 HOURS MUCH DRIER THAN ORIGINALLY FORECAST
AND HIGHEST WPC-BASED QPF TOTALS THROUGH SATURDAY MORNING TO THE
NORTH AND WEST OF THE FORECAST AREA...WITH IN-CWA TOTALS BELOW THE
1 TO 6-HOUR FLASH FLOOD GUIDANCE BETWEEN 2 AND 3 INCHES...WILL
KEEP THE ESF STATEMENT GOING FOR LOCALIZED URBAN/SMALL STREAM
FLOODING POTENTIAL BUT NO FLASH FLOOD WATCH AT THIS TIME.
SPC HAS A 5 PCT CHANCE FOR WIND GUSTS WITH STEEP LOW-LEVEL LAPSE
RATES PRODUCING AN INVERTED V DRY ADIABATIC PROFILE UP TO 4K TO 5K
FT ON WESTERN CWA FORECAST SOUNDINGS LATE THIS AFTERNOON/EARLY
EVENING IF FORECAST CAPE VALUES CAN BE REALIZED.
SATURDAY AND SUNDAY...FORECAST CONFIDENCE...MEDIUM
LATEST MODEL GUIDANCE SUGGEST THAT A SURFACE FRONTAL BOUNDARY AND
UPPER LEVEL SHORTWAVE AXIS WILL BE POSITIONED JUST TO THE WEST OF
THE FORECAST AREA SATURDAY MORNING. SHOWERS AND STORMS ARE LIKELY
AHEAD OF THESE DURING SATURDAY MORNING...WITH A CHANCE CONTINUING
INTO THE AFTERNOON AS THE TROUGH MOVES THROUGH AND THE FRONT
STALLS NEAR THE WI/IL BORDER.
ANOTHER SHORTWAVE WILL MOVE THROUGH SATURDAY EVENING AND
OVERNIGHT...BUT KEPT THE FORECAST DRY DUE TO MUCH DRIER AIR ALOFT.
SUNDAY THEN LOOKS LIKE A PLEASANT DAY IN BETWEEN LOW PRESSURE
SYSTEMS.
HIGH TEMPERATURES SATURDAY SHOULD BE RIGHT AROUND NORMAL...RISING
TO A COUPLE DEGREES ABOVE NORMAL FOR SUNDAY.
MONDAY THROUGH THURSDAY...FORECAST CONFIDENCE...MEDIUM
SHOWERS AND STORMS ARE LIKELY IN THE WEST BY DAYBREAK MONDAY
MORNING AND THEN ACROSS THE FORECAST AREA DURING THE DAY AS A
COLD FRONT MOVES THROUGH. SOME STRONGER STORMS ARE POSSIBLE
MONDAY...BUT THIS WILL BE DEPENDENT ON THE TIMING OF THE FRONT. IT
LOOKS LIKE A DECENT AMOUNT OF INSTABILITY TO GO ALONG WITH AROUND
40 KNOTS OF 0-6 KM BULK SHEAR. MODELS ARE HINTING AT THE FRONT
MOVING THROUGH EARLIER IN THE DAY THOUGH...WHICH WOULD LIMIT
THE TIME FOR DAYTIME HEATING AND RESULTANT DESTABILIZATION.
IT LOOKS MAINLY DRY TUESDAY AND WEDNESDAY WITH THE FRONTAL
BOUNDARY AND HIGHER MOISTURE/INSTABILITY REMAINING SOUTH.
A RETURN OF MOISTURE UNDER SOUTHERLY LOW LEVEL FLOW MAY BRING
SHOWERS AND STORMS BACK TO THE AREA FOR THURSDAY.
TEMPERATURES FOR THE MONDAY THROUGH THURSDAY TIME PERIOD SHOULD
REMAIN NEAR TO A COUPLE DEGREES ABOVE NORMAL.
AVIATION/12Z TAFS/...MOISTURE ADVECTION IS BRINGING IN SOME MVFR/IFR
CIGS AND REDUCED VISIBILITIES ALONG AND JUST AHEAD OF THE SURFACE
WARM FRONT. THESE LOWER CIGS/VSBYS SHOULD CLEAR THE TAF SITES BY
LATE MORNING AS THE FRONT LIFTS NORTH THEN STALLS OVER CENTRAL
WISCONSIN. SOME CONCERN FOR KMKE...AND POSSIBLY KENW...THAT IF
WINDS ARE MORE SOUTHEAST THAN SOUTH TODAY THAT THE FRONT MAY NOT
CLEAR TO THE NORTH AND WILL LEAVE THOSE SITES WITH LESS THAN VFR
CONDITIONS THE ENTIRE DAY.
WILL GO WITH THE CONSENSUS OF THE MODEL GUIDANCE AND GO WITH
PREVAILING VFR TODAY...WITH BRIEF MVFR CIGS/VSBYS WITH SCATTERED
SHOWER AND ISOLATED THUNDERSTORMS PASSING THROUGH WITH THE FRONT
THIS MORNING.
LIKELY TO SEE MVFR SHOWERS AND THUNDERSTORMS SPREAD FROM WEST TO
EAST LATER THIS AFTERNOON AND EVENING WITH LOW PRESSURE PASSING
THROUGH THE REGION. AGAIN WILL GO WITH NO LOWER THAN MVFR
CIGS/VSBYS FOR NOW...THOUGH IFR VSBYS IN HEAVY RAIN
POSSIBLE...ESPECIALLY AT KMSN. NAM GUIDANCE HINTING AT IFR/LIFR
CIGS AS THE PCPN TAPERS OFF TOWARDS 12Z SATURDAY...BUT CONSENSUS
TRACK OF THE LOW KEEPS ENOUGH GRADIENT AT TAF SITES TO KEEP LOW
LEVELS MIXED WELL ENOUGH TO PREVENT LOW STRATUS AND FOG...BUT IT
WILL HAVE TO BE WATCHED FOR WITH THE NEXT ROUND OF MODEL DATA.
MARINE...SOUTHEAST TO SOUTH WINDS WILL GUST TO BETWEEN 20 AND 25
KNOTS AS LOW PRESSURE APPROACHES...BUT NOT FREQUENTLY ENOUGH OR
LONG ENOUGH TO WARRANT A SMALL CRAFT ADVISORY AT THIS TIME.
HOWEVER SMALL VESSEL OPERATORS SHOULD EXERCISE
CAUTION...ESPECIALLY NORTH OF MILWAUKEE WHERE THE LONGER FETCH
WILL BUILD HIGHER WAVES.
BEACHES...THERE IS A MODERATE SWIM RISK AT THE LAKE MICHIGAN
BEACHES FROM SHEBOYGAN TO KENOSHA THIS MORNING THROUGH THIS
EVENING WHERE SOUTHEAST TO SOUTH WINDS INCREASING TO 10 TO 20
KNOTS WILL BUILD HIGH WAVES AND RESULT IN STRONG CURRENTS ALONG
THE SHORE.
RACINE COUNTY IS LISTED AS HAVING A LOW RISK IN THE SURF ZONE
FORECAST AS SOME SHELTERING DUE TO SHORELINE TOPOGRAPHY RESULTED
IN SLIGHTLY LOWER AVERAGE WAVE HEIGHTS...BUT SWIMMERS SHOULD STILL
BE ALERT FOR STRONG CURRENTS AND HIGHER WAVES AT WINDWARD-FACING
BEACHES.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...REM
SATURDAY THROUGH THURSDAY...DDV
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
706 AM CDT FRI AUG 29 2014
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 309 AM CDT FRI AUG 29 2014
THE MAIN FORECAST CONCERN IS WITH THE RAIN CHANCES THROUGH THE
PERIOD.
LOCAL AND REGIONAL RADARS SHOWING AN AREA OF SHOWERS AND STORMS
ACROSS SOUTHERN MINNESOTA INTO CENTRAL IOWA. THIS ACTIVITY HAS
BEEN MOVING NORTHEAST AND THE 29.00Z HRRR SEEMED TO HAVE A DECENT
HANDLE ON THIS. IT SUGGESTS THAT IT WILL CONTINUE TO MOVE
NORTHEAST INTO THE AREA AND MAY SHOW A DIMINISHING TREND AS IT
OUTRUNS THE AVAILABLE CAPE. THE 29.06Z RAP ANALYSIS SUGGESTED
THERE WAS AROUND 250 J/KG OF MU CAPE OVER THE WESTERN SECTIONS
WITH THIS DROPPING TO NEAR ZERO OVER WESTERN AND CENTRAL
WISCONSIN. WHILE THE THUNDER MAY DIMINISH AS THE SYSTEM CONTINUES
TO WORK NORTHEAST...THE AREAL COVERAGE MAY NOT CHANGE MUCH AS THE
29.05Z RAP INDICATES THE ACTIVITY IS ON THE NOSE OF THE 850 MB LOW
LEVEL JET AND THIS MAINTAINS ITS INTENSITY AS IT LIFTS NORTHEAST
THROUGH THE AREA FOR THE REMAINDER OF THE NIGHT. PLAN TO START THE
DAY WITH AT LEAST A 70 PERCENT CHANCE OF RAIN OVER MUCH OF CENTRAL
INTO PARTS OF WESTERN WISCONSIN AND THEN DIMINISH THESE DOWN TO 30
TO 50 PERCENT BY LATE MORNING AS THE AREA GETS IN BETWEEN
SYSTEMS. BOTH THE HRRR AND 29.00Z HI-RES ARW SUGGEST MOST IF NOT
ALL OF THE AREA COULD BE RAIN FREE FOR A SHORT WHILE LATE THIS
MORNING.
THIS DRY PERIOD WILL NOT LAST VERY LONG AS THE MEAN LONG WAVE
TROUGH WILL START TO APPROACH FROM THE WEST IN THE AFTERNOON WITH
A STRONG SHORT WAVE TROUGH EMBEDDED IN THE FLOW. THIS IS EXPECTED
TO PRODUCE WEAK TO MODERATE PV ADVECTION IN THE 500-300 MB LAYER
DURING THE AFTERNOON AND EVENING. THE 29.00Z NAM SUGGEST THERE
COULD ALSO BE SOME COUPLED JET DYNAMICS FROM THE RIGHT ENTRANCE
REGION OF THE MAIN JET CORE ACROSS THE NORTHERN GREAT LAKES INTO
SOUTHEAST CANADA AND FROM THE LEFT EXIT REGION OF A SECONDARY JET
ROUNDING THE BASE OF THE LONG WAVE TROUGH. THE CAPE WILL INCREASE
IN THE AFTERNOON...ESPECIALLY ACROSS THE SOUTHEAST TWO-THIRDS OF
THE FORECAST AREA...WHERE THE NAM INDICATES THE POTENTIAL OF
1500-2500 J/KG OF ML CAPE. THIS MAY BE A LITTLE ON THE HIGH SIDE
AS IT IS SHOWING WIDESPREAD LOWER 70S DEW POINTS WHEN THESE MAY
ONLY BE IN THE UPPER 60S TO AROUND 70. NONE THE LESS...EXPECT TO
SEE AN INCREASE IN THE ACTIVITY DURING THE AFTERNOON INTO THE
EVENING AND WILL PUSH THE RAIN CHANCES BACK UP INTO THE 70 TO 80
PERCENT RANGE BY EVENING WHEN THE FORCING IS THE BEST. THE
ACTIVITY SHOULD START TO MOVE OUT OF THE AREA LATE TONIGHT INTO
SATURDAY MORNING AND THEN END DURING THE AFTERNOON AS THE LONG
WAVE TROUGH MOVES PAST THE AREA. IF THE CAPE ADVERTISED BY THE
MODELS CAN BE REALIZED...THEN THERE COULD SOME POTENTIAL FOR
SEVERE STORMS. THE 0-3KM BULK SHEAR SHOULD BE IN THE 30 TO 40 KNOT
RANGE WHICH WOULD BE ENOUGH TO SUPPORT SOME STRONG WINDS.
ONCE THE RAIN ENDS SATURDAY...IT APPEARS THAT SOME WEAK RIDGING
WILL BUILD OVER THE AREA FOR A DRY SATURDAY NIGHT. THIS RIDGING
WILL THEN QUICKLY BE PUSHED OUT OF THE AREA SUNDAY AS YET ANOTHER
LONG WAVE TROUGH STARTS TO COME IN FROM THE NORTHERN ROCKIES.
HOWEVER...IT APPEARS THE TIMING OF THIS SYSTEM WOULD BE SUCH THAT
THERE WILL ONLY BE A SMALL CHANCE FOR SOME ADDITIONAL RAINS ACROSS
THE FAR WESTERN SECTIONS SUNDAY AFTERNOON.
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 309 AM CDT FRI AUG 29 2014
PRETTY DECENT AGREEMENT BETWEEN THE MEDIUM RANGE MODELS THAT THIS
NEXT SYSTEM WILL MOVE ACROSS THE UPPER MIDWEST SUNDAY NIGHT AND
MONDAY. THE 29.00Z ECMWF AND GFS BOTH INDICATE THE EMBEDDED SHORT
WAVE TROUGH COULD PRODUCE MODERATE TO STRONG PV ADVECTION IN THE
500-300 MB LAYER WHILE THE 29.00Z GEM SHOWS WEAK TO MODERATE PV
ADVECTION. ALL THREE MODELS DO SHOW THE COLD FRONT WITH THIS
SYSTEM PASSING THROUGH LATE SUNDAY NIGHT INTO MONDAY MORNING WITH
A SOLID SHIELD OF RAIN ALONG AND AHEAD OF IT. WILL SHOW 60 TO 80
PERCENT RAIN CHANCES SUNDAY NIGHT FROM EAST TO WEST AND 30 TO 60
PERCENT CHANCES MONDAY. HOWEVER...IF THE TIMING OF THE SYSTEM
REMAINS THE SAME...THE MONDAY RAIN CHANCES MAY HAVE TO BE
INCREASED...ESPECIALLY IN THE MORNING. THE TIMING OF THE FRONT IS
NOT IDEAL FOR SEVERE CHANCES...BUT THE GFS DOES SHOW 500-1000 J/KG
OF ML CAPE PERSISTING SUNDAY NIGHT AHEAD OF THE FRONT WITH AROUND
40 KNOTS OF 0-6KM SHEAR. THIS WOULD BE SUFFICIENT TO SUPPORT SOME
STRONGER STORMS THAT COULD PRODUCE SOME STRONG WINDS. ANOTHER COLD
FRONT LOOKS TO MOVE THROUGH LATE IN THE PERIOD FOR ADDITIONAL RAIN
CHANCES WEDNESDAY NIGHT INTO THURSDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 700 AM CDT FRI AUG 29 2014
RAIN AREA SHIFTING NORTHWARD SO FEEL ANY RAIN WILL BE OUT OF THE
AIRFIELDS BY MID-MORNING. AS UPPER SYSTEM CONTINUES TO MOVE TOWARD
THE REGION...LOOKING LIKE THE DRY SLOT WILL PROVIDE FOR SOME
PARTIAL SUNSHINE FOR A TIME LATE THIS MORNING. BUT THAT WILL ONLY
HELP TO DESTABLIZE THE ATMOSPHERE...LEADING TO MORE CONVECTIVE
DEVELOPMENT. VARIOUS MESOSCALE MODEL SOLUTIONS SUGGEST SCATTERED
CONVECTION DEVELOPS IN THE WARM AND MOIST AIR...WITH A MORE
FOCUSED BAND OF STORMS WHERE SOME FRONTAL CONVERGENCE LOOKS TO
EXIST. THIS LOOKS TO BE PRIMARILY NEAR THE KRST AIRFIELD. EITHER
WAY...BOTH TAF FORECASTS WILL INCLUDE A TSRA RISK FOR SEVERAL
HOURS FROM THE AFTERNOON INTO EVENING. ONCE THE RAIN MOVES THROUGH
BY MIDNIGHT...LOW STRATUS AND FOG LOOK TO BE A GOOD BET...WITH
LIFR CONDITIONS ANTICIPATED.
&&
.HYDROLOGY...
ISSUED AT 309 AM CDT FRI AUG 29 2014
PLAN TO CONTINUE WITH THE HYDROLOGIC OUTLOOK THIS MORNING. NOT
OVERLY CONCERNED ABOUT ANY FLOODING THREATS AS THE RAIN THURSDAY
DID NOT TURN OUT TO BE AS HEAVY AS EXPECTED AND THE CURRENT
FORECAST IS FOR ANOTHER 1 TO 1.5 INCHES THROUGH SATURDAY. WILL
LIKELY BE SOME LOCALLY HIGHER AMOUNTS THOUGH AS THE CONDITIONS ARE
STILL IN PLACE FOR SOME HEAVY RAIN TO OCCUR. PRECIPITABLE WATERS
WILL REMAIN IN THE 1.5 TO 2 INCH RANGE WITH WARM CLOUD DEPTHS OF
3.5 TO 4 KM WHICH WILL HELP TO MAKE THE CONVECTION EFFICIENT RAIN
PRODUCERS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...04
LONG TERM...04
AVIATION...MW
HYDROLOGY...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
309 AM CDT FRI AUG 29 2014
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 309 AM CDT FRI AUG 29 2014
THE MAIN FORECAST CONCERN IS WITH THE RAIN CHANCES THROUGH THE
PERIOD.
LOCAL AND REGIONAL RADARS SHOWING AN AREA OF SHOWERS AND STORMS
ACROSS SOUTHERN MINNESOTA INTO CENTRAL IOWA. THIS ACTIVITY HAS
BEEN MOVING NORTHEAST AND THE 29.00Z HRRR SEEMED TO HAVE A DECENT
HANDLE ON THIS. IT SUGGESTS THAT IT WILL CONTINUE TO MOVE
NORTHEAST INTO THE AREA AND MAY SHOW A DIMINISHING TREND AS IT
OUTRUNS THE AVAILABLE CAPE. THE 29.06Z RAP ANALYSIS SUGGESTED
THERE WAS AROUND 250 J/KG OF MU CAPE OVER THE WESTERN SECTIONS
WITH THIS DROPPING TO NEAR ZERO OVER WESTERN AND CENTRAL
WISCONSIN. WHILE THE THUNDER MAY DIMINISH AS THE SYSTEM CONTINUES
TO WORK NORTHEAST...THE AREAL COVERAGE MAY NOT CHANGE MUCH AS THE
29.05Z RAP INDICATES THE ACTIVITY IS ON THE NOSE OF THE 850 MB LOW
LEVEL JET AND THIS MAINTAINS ITS INTENSITY AS IT LIFTS NORTHEAST
THROUGH THE AREA FOR THE REMAINDER OF THE NIGHT. PLAN TO START THE
DAY WITH AT LEAST A 70 PERCENT CHANCE OF RAIN OVER MUCH OF CENTRAL
INTO PARTS OF WESTERN WISCONSIN AND THEN DIMINISH THESE DOWN TO 30
TO 50 PERCENT BY LATE MORNING AS THE AREA GETS IN BETWEEN
SYSTEMS. BOTH THE HRRR AND 29.00Z HI-RES ARW SUGGEST MOST IF NOT
ALL OF THE AREA COULD BE RAIN FREE FOR A SHORT WHILE LATE THIS
MORNING.
THIS DRY PERIOD WILL NOT LAST VERY LONG AS THE MEAN LONG WAVE
TROUGH WILL START TO APPROACH FROM THE WEST IN THE AFTERNOON WITH
A STRONG SHORT WAVE TROUGH EMBEDDED IN THE FLOW. THIS IS EXPECTED
TO PRODUCE WEAK TO MODERATE PV ADVECTION IN THE 500-300 MB LAYER
DURING THE AFTERNOON AND EVENING. THE 29.00Z NAM SUGGEST THERE
COULD ALSO BE SOME COUPLED JET DYNAMICS FROM THE RIGHT ENTRANCE
REGION OF THE MAIN JET CORE ACROSS THE NORTHERN GREAT LAKES INTO
SOUTHEAST CANADA AND FROM THE LEFT EXIT REGION OF A SECONDARY JET
ROUNDING THE BASE OF THE LONG WAVE TROUGH. THE CAPE WILL INCREASE
IN THE AFTERNOON...ESPECIALLY ACROSS THE SOUTHEAST TWO-THIRDS OF
THE FORECAST AREA...WHERE THE NAM INDICATES THE POTENTIAL OF
1500-2500 J/KG OF ML CAPE. THIS MAY BE A LITTLE ON THE HIGH SIDE
AS IT IS SHOWING WIDESPREAD LOWER 70S DEW POINTS WHEN THESE MAY
ONLY BE IN THE UPPER 60S TO AROUND 70. NONE THE LESS...EXPECT TO
SEE AN INCREASE IN THE ACTIVITY DURING THE AFTERNOON INTO THE
EVENING AND WILL PUSH THE RAIN CHANCES BACK UP INTO THE 70 TO 80
PERCENT RANGE BY EVENING WHEN THE FORCING IS THE BEST. THE
ACTIVITY SHOULD START TO MOVE OUT OF THE AREA LATE TONIGHT INTO
SATURDAY MORNING AND THEN END DURING THE AFTERNOON AS THE LONG
WAVE TROUGH MOVES PAST THE AREA. IF THE CAPE ADVERTISED BY THE
MODELS CAN BE REALIZED...THEN THERE COULD SOME POTENTIAL FOR
SEVERE STORMS. THE 0-3KM BULK SHEAR SHOULD BE IN THE 30 TO 40 KNOT
RANGE WHICH WOULD BE ENOUGH TO SUPPORT SOME STRONG WINDS.
ONCE THE RAIN ENDS SATURDAY...IT APPEARS THAT SOME WEAK RIDGING
WILL BUILD OVER THE AREA FOR A DRY SATURDAY NIGHT. THIS RIDGING
WILL THEN QUICKLY BE PUSHED OUT OF THE AREA SUNDAY AS YET ANOTHER
LONG WAVE TROUGH STARTS TO COME IN FROM THE NORTHERN ROCKIES.
HOWEVER...IT APPEARS THE TIMING OF THIS SYSTEM WOULD BE SUCH THAT
THERE WILL ONLY BE A SMALL CHANCE FOR SOME ADDITIONAL RAINS ACROSS
THE FAR WESTERN SECTIONS SUNDAY AFTERNOON.
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 309 AM CDT FRI AUG 29 2014
PRETTY DECENT AGREEMENT BETWEEN THE MEDIUM RANGE MODELS THAT THIS
NEXT SYSTEM WILL MOVE ACROSS THE UPPER MIDWEST SUNDAY NIGHT AND
MONDAY. THE 29.00Z ECMWF AND GFS BOTH INDICATE THE EMBEDDED SHORT
WAVE TROUGH COULD PRODUCE MODERATE TO STRONG PV ADVECTION IN THE
500-300 MB LAYER WHILE THE 29.00Z GEM SHOWS WEAK TO MODERATE PV
ADVECTION. ALL THREE MODELS DO SHOW THE COLD FRONT WITH THIS
SYSTEM PASSING THROUGH LATE SUNDAY NIGHT INTO MONDAY MORNING WITH
A SOLID SHIELD OF RAIN ALONG AND AHEAD OF IT. WILL SHOW 60 TO 80
PERCENT RAIN CHANCES SUNDAY NIGHT FROM EAST TO WEST AND 30 TO 60
PERCENT CHANCES MONDAY. HOWEVER...IF THE TIMING OF THE SYSTEM
REMAINS THE SAME...THE MONDAY RAIN CHANCES MAY HAVE TO BE
INCREASED...ESPECIALLY IN THE MORNING. THE TIMING OF THE FRONT IS
NOT IDEAL FOR SEVERE CHANCES...BUT THE GFS DOES SHOW 500-1000 J/KG
OF ML CAPE PERSISTING SUNDAY NIGHT AHEAD OF THE FRONT WITH AROUND
40 KNOTS OF 0-6KM SHEAR. THIS WOULD BE SUFFICIENT TO SUPPORT SOME
STRONGER STORMS THAT COULD PRODUCE SOME STRONG WINDS. ANOTHER COLD
FRONT LOOKS TO MOVE THROUGH LATE IN THE PERIOD FOR ADDITIONAL RAIN
CHANCES WEDNESDAY NIGHT INTO THURSDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1140 PM CDT THU AUG 28 2014
ALTHOUGH RAIN SHOWERS FROM EARLIER THIS EVENING HAVE MOVED
NORTHEAST OF TAF AIRFIELDS...A SECONDARY AREA OF CONVECTION HAS
DEVELOPED ACROSS CENTRAL IA. THESE STORMS ARE EXPECTED TO WEAKEN
AS THEY MOVE NORTHEASTWARD...BUT SHOULD IMPACT KRST AND KLSE
BETWEEN 29.08 AND 29.14Z. PERIODS OF HEAVY RAIN AND VISIBILITY
RESTRICTIONS TO ONE MILE WILL BE THE PRIMARY IMPACTS. EXPECT
MVFR/IFR CEILINGS TO PERSIST THROUGH THE NIGHT ONLY TO SLOWLY LIFT
FRIDAY MORNING. ADDITIONAL SHOWERS AND THUNDERSTORMS ARE EXPECTED
FRIDAY AFTERNOON/EVENING WITH AN APPROACHING COLD FRONT. WILL
CONTINUE TO HIGHLIGHT THIS THREAT USING TEMPO GROUPS UNTIL BETTER
TIMING/COVERAGE CERTAINTY IS ACHIEVED. LIGHT SOUTHEAST WIND WILL
GRADUALLY BECOME MORE SOUTHERLY THROUGH THE PERIOD.
&&
.HYDROLOGY...
ISSUED AT 309 AM CDT FRI AUG 29 2014
PLAN TO CONTINUE WITH THE HYDROLOGIC OUTLOOK THIS MORNING. NOT
OVERLY CONCERNED ABOUT ANY FLOODING THREATS AS THE RAIN THURSDAY
DID NOT TURN OUT TO BE AS HEAVY AS EXPECTED AND THE CURRENT
FORECAST IS FOR ANOTHER 1 TO 1.5 INCHES THROUGH SATURDAY. WILL
LIKELY BE SOME LOCALLY HIGHER AMOUNTS THOUGH AS THE CONDITIONS ARE
STILL IN PLACE FOR SOME HEAVY RAIN TO OCCUR. PRECIPITABLE WATERS
WILL REMAIN IN THE 1.5 TO 2 INCH RANGE WITH WARM CLOUD DEPTHS OF
3.5 TO 4 KM WHICH WILL HELP TO MAKE THE CONVECTION EFFICIENT RAIN
PRODUCERS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...04
LONG TERM...04
AVIATION...ROGERS
HYDROLOGY...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1140 PM CDT THU AUG 28 2014
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 329 PM CDT THU AUG 28 2014
MAIN FOCUS FOR THE NEXT 24 TO 48 HOURS IS ON THE HEAVY RAINFALL
POTENTIAL AS A FEW ROUNDS OF STORMS LIFT THROUGH THE UPPER
MISSISSIPPI RIVER VALLEY.
AS OF MID AFTERNOON...WATER VAPOR IMAGERY OVERLAID WITH RAP 500MB
RAP HEIGHTS SHOWED THE SHORTWAVE TROUGH PUSHING OFF THE COLORADO
ROCKIES WITH WEAK IMPULSES LIFTING THROUGH THE CENTRAL PLAINS
TOWARD THE UPPER MIDWEST. ONE SUCH WAVE IS BRINGING THE SHIELD OF
MAINLY RAIN SHOWERS THIS AFTERNOON...WHILE ANOTHER ONE IS NOTED
NEAR THE TX PANHANDLE INTO SOUTHERN KANSAS. THIS ONE...ALONG WITH
THE MAIN TROUGH...WILL BE OUR PLAYER FOR FRIDAY AFTERNOON AND
EVENING.
THE SURFACE HIGH PRESSURE ANCHORED OVER THE GREAT LAKES KEPT FLOW
OF DRIER AIR...LIMITING THE FORWARD PROGRESS OF RAIN SHIELD. A LOT
OF THE MOISTURE WENT INTO SATURATION...AND COMBINED WITH THE
WEAKENING LLJ MOISTURE TRANSPORT FROM THIS MORNING...THE HEAVIER
RAINFALL DID NOT MATERIALIZE. WITH THAT SAID...THE ENVIRONMENT
WILL BEGIN TO BECOME MORE FAVORABLE TONIGHT AND RECENT 1-HR
RAINFALL TOTALS HAVE BEEN GENERALLY 0.1 TO 0.2 INCH...WITH SOME
ISOLATED 0.3-0.5 AMOUNTS.
VERY LITTLE INSTABILITY FOUND ACROSS THE AREA WHICH IS KEEPING
ACTIVITY AS SHOWERS/RAIN. WENT AHEAD AND LIMITED THUNDER CHANCES
TO ISOLATED/SCATTERED THROUGH THE OVERNIGHT HOURS...ESPECIALLY
MN/WI AREAS. IT WILL BE MORE STEADY RAINFALL. AS THE CURRENT
SHIELD OF RAIN LIFTS NORTHEAST...EXPECTING THE BACK EDGES TO FILL
IN SOME KEEPING THE HIGHER POPS IN PLACE THROUGH THE OVERNIGHT.
THE TIMING OF ANY SPECIFIC UPPER LEVEL WAVES...WITH CONFLICTING
STRENGTH IN MOISTURE TRANSPORT AND SURFACE FOCUS...LENDS A BIT
LOWER CONFIDENCE IN WHERE HEAVIEST RAINFALL WILL FALL. WHAT HAS
HIGHER CONFIDENCE IS THAT THE ATMOSPHERE SHOULD BETTER PRIMED FOR
EFFICIENT RAIN PRODUCERS. NO CHANGES TO THE IDEA THAT PWATS ARE
HIGH...WARM CLOUD DEPTHS ARE ABOVE 4 KM...AND THERE IS A
CONTINUOUS FLOW OF MOISTURE STREAMING IN FROM THE SOUTHWEST IN
ADVANCE OF THE SHORTWAVE.
PERUSAL OF 28.12Z MODELS SHOW SIGNALS FOR ANOTHER IMPULSE TO
SPARK CONVECTION OVERNIGHT ACROSS WESTERN INTO SOUTHWEST IOWA.
THIS WOULD LIFT THROUGH NORTHEAST IOWA AND SOUTHEAST MINNESOTA
EARLY MORNING. AFTER THE MORNING LLJ WEAKENS...THERE SEEMS TO NOT
BE ANOTHER KICKER UNTIL LATE FRIDAY AFTERNOON AND EVENING. AS
SUCH...THE LATE MORNING AND EARLY AFTERNOON HOURS COULD END UP
DRIER...AND HAVE TRIED TO REFLECT THIS THINKING IN THE HOURLY
POPS.
THE MORE SIGNIFICANT WAVE ARRIVES FRIDAY AFTERNOON THROUGH THE
EARLY MORNING HOURS SATURDAY. FINALLY THE MAIN SHORTWAVE TROUGH
ENERGY WILL BE FELT...AND WITH A GOOD FEED OF MOISTURE TRANSPORT
AND WARM AIR ADVECTION...THERE SHOULD BE WIDESPREAD SHOWERS AND
ISOLATED/EMBEDDED THUNDERSTORMS THROUGHOUT FROM LATE AFTERNOON
ONWARD.
ALTHOUGH THE FAVORABLE ATMOSPHERIC CONDITIONS WILL BE IN PLACE
FOR HEAVY RAINFALL TOMORROW...THE LACK OF HIGHER RAINFALL TOTALS
TODAY DAMPENS THE OVERALL FLASH FLOODING THREAT. RAINFALL TOTALS
THROUGH SATURDAY HAVE BEEN TEMPERED A BIT...AND ARE MORE IN THE
1-2 INCH RANGE. A LOT OF THE AREA CAN TAKE THIS TYPE OF RAINFALL.
OF COURSE LOCALLY HIGHER AMOUNTS WILL BE POSSIBLE...BUT FEEL THE
OVERALL THREAT IS REDUCED COMPARED TO THE THINKING IN THE PAST 24
HOURS.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 329 PM CDT THU AUG 28 2014
THE MAIN FOCUS IN THE LONG TERM IS CENTERED ON THE THREAT FOR
SEVERE WEATHER SUNDAY NIGHT INTO MONDAY. WITH THE HOLIDAY WEEKEND
APPROACHING...AND WITH MANY FOLKS PLANNING OUTDOOR ACTIVITIES...IT
IS THIS PERIOD THAT WARRANTS CLOSE WATCHING.
IN THE UPPER LEVELS...THE 28.12Z GUIDANCE FOLLOWED THE PAST
SEVERAL MODEL CYCLES IN SHOWING A DIGGING WESTERN CONUS LONGWAVE
TROUGH APPROACHING THE NORTHERN PLAINS BY SUNDAY EVENING. 250MB
JET DYNAMICS PUTS THE AREA IN A FAVORABLE RIGHT ENTRANCE
REGION...AND THIS JET STRENGTHENS BETWEEN 00-06Z MONDAY.
AT THE SURFACE...A COLD FRONT LOOKS LIKELY TO MOVE ACROSS
MINNESOTA LATE SUNDAY NIGHT...REACHING THE MISSISSIPPI RIVER EARLY
MONDAY MORNING. MUCAPE RANGES FROM 1500 TO 2000 J/KG ACROSS THE
REGION LATE SUNDAY...WITH HEALTHY PROFILES AS NCAPE VALUES
APPROACH 0.15. THIS IS AIDED BY 700-500MB LAPSE RATES AROUND
7.5C/KM. THE SHEAR ENVIRONMENT IS A BIT MUDDLED BETWEEN THE
VARIOUS GUIDANCE...BUT OVERALL 0-3KM SHEAR VALUES RANGE FROM 20 TO
30 KTS. HODOGRAPHS SHOW SOME CURVATURE BUT A LOT OF THE SHEAR IS
SPEED RELATED. OVERALL...THE CURRENT TIMING WOULD SUGGEST
CONVECTION TO DEVELOP IN THE AFTERNOON ACROSS THE EASTERN DAKOTAS
/ WESTERN INTO CENTRAL MINNESOTA...POSSIBLY AS SUPERCELLS...THEN
MERGE IN LINE SEGMENTS TOWARD THE WESTERN CWA IF MAINTAINED.
THERE ARE STRONG MOISTURE TRANSPORT SIGNALS WITH HIGHER PWATS
RETURNING...SO THERE COULD BE SOME HEALTHY RAIN PRODUCERS. THE
MAIN LIMITING FACTOR WOULD BE STORM SPEED...WHICH SHOULD BE RATHER
PROGRESSIVE. REGARDLESS...MAIN THREATS LOOK TO BE HEAVY
RAIN...DAMAGING WINDS...AND LARGE HAIL. AT THIS TIME...GIVEN
TIMING...WEST OF THE MS RIVER WOULD BE MORE FAVORABLE AND THIS
LINES UP WELL WITH THE CURRENT DAY 4 OUTLOOK FROM THE SPC.
OVERALL...WILL NEED TO WATCH THIS PERIOD.
THE FRONT SLIDES INTO WESTERN WISCONSIN MONDAY MORNING...WHICH
MAY ALLOW FOR ANOTHER ROUND OF DESTABILIZATION AND STRONG STORMS
FOR OUR EASTERN AREAS MONDAY AFTERNOON. THAT IS A BIT MORE
UNCERTAIN BUT IF THE SYSTEM SLOWS DOWN...WHICH SEEMS TO BE A
TREND...THIS PERIOD MAY NEED TO BE WATCHED CLOSER.
THE TUESDAY-THURSDAY PERIOD LOOKS TO FEATURE ZONAL UPPER LEVEL
FLOW WITH THE POSSIBILITY OF A FEW RIPPLES SLIDING THROUGH. NOT
MUCH CONSISTENCY IN THE MODEL RUNS TO ADD ANY DETAILS AT THIS
POINT. LOTS OF WEATHER TO GET THROUGH UNTIL THEN. SLIGHT CHANCES
WITH SEASONABLE TEMPERATURES LOOKS GOOD AT THIS POINT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1140 PM CDT THU AUG 28 2014
ALTHOUGH RAIN SHOWERS FROM EARLIER THIS EVENING HAVE MOVED
NORTHEAST OF TAF AIRFIELDS...A SECONDARY AREA OF CONVECTION HAS
DEVELOPED ACROSS CENTRAL IA. THESE STORMS ARE EXPECTED TO WEAKEN
AS THEY MOVE NORTHEASTWARD...BUT SHOULD IMPACT KRST AND KLSE
BETWEEN 29.08 AND 29.14Z. PERIODS OF HEAVY RAIN AND VISIBILITY
RESTRICTIONS TO ONE MILE WILL BE THE PRIMARY IMPACTS. EXPECT
MVFR/IFR CEILINGS TO PERSIST THROUGH THE NIGHT ONLY TO SLOWLY LIFT
FRIDAY MORNING. ADDITIONAL SHOWERS AND THUNDERSTORMS ARE EXPECTED
FRIDAY AFTERNOON/EVENING WITH AN APPROACHING COLD FRONT. WILL
CONTINUE TO HIGHLIGHT THIS THREAT USING TEMPO GROUPS UNTIL BETTER
TIMING/COVERAGE CERTAINTY IS ACHIEVED. LIGHT SOUTHEAST WIND WILL
GRADUALLY BECOME MORE SOUTHERLY THROUGH THE PERIOD.
&&
.HYDROLOGY...THROUGH SATURDAY MORNING
ISSUED AT 329 PM CDT THU AUG 28 2014
WITH LESS THAN EXPECTED RAINFALL TODAY...OVERALL TOTALS THROUGH
SATURDAY HAVE BEEN REDUCED TO THE 1.5 TO 2.5 INCH RANGE. THE SURGE
IN EFFICIENT RAIN PRODUCING ATMOSPHERIC CONDITIONS...CHARACTERIZED
BY WARM CLOUD DEPTHS 3.5 TO 4.0 KM...PWATS 1.5 TO 2.0 INCHES...AND
LOWER 70F DEWPOINTS...WILL REMAIN IN PLACE THROUGH EARLY SATURDAY.
OVERALL...THE THREAT FOR EXCESSIVE RAINFALL HAS BEEN DIMINISHED A
BIT AS THE ROUNDS OF STORMS LOOK PROGRESSIVE ENOUGH AND MUCH OF
THE AREA CAN HANDLE THE EXPECTED AMOUNTS. AS SUCH...WILL CONTINUE
THE HYDROLOGIC OUTLOOK /ESFARX/
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...ZT
LONG TERM....ZT
AVIATION...ROGERS
HYDROLOGY....ZT
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
437 PM MDT FRI AUG 29 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 150 PM MDT FRI AUG 29 2014
A WELL-DEFINED SHORTWAVE CONTINUES TO SLIDE EASTWARD ACROSS THE CWA
THIS AFTN ALONG THE NORTHERN FRINGE OF BROAD UPPER-LEVEL RIDGING IN
PLACE OVER THE CENTRAL ROCKIES. WATER VAPOR SATELLITE SHOWED THIS
FEATURE OVER NORTHEAST WY AS OF 19Z MOVING QUICKLY TOWARD SOUTHWEST
SD AND THE NORTHERN PANHANDLE. CONVECTIVE CHANCES ARE THE MAIN ISSUE
IN THE NEAR TERM. ASIDE FROM MOUNTAIN CONVECTION...SHOWER AND TSTM
CHANCES WILL BE ASSOCIATED WITH LARGER SCALE FORCING IN ADVANCE OF
THE AFOREMENTIONED WAVE. THE NAM IS STILL THE MOST BULLISH WITH QPF
OVER OUR NORTHEAST ZONES WHILE THE HRRR COMPOSITE REFLECTIVITY SHOWS
FAIRLY MODEST CONVECTIVE COVERAGE. CONFIDENCE IS FAIRLY LOW IN JUST
HOW WIDESPREAD THINGS WILL BE TODAY GIVEN WEAK SUBSIDENCE BENEATH
THE RIDGE...AND RECENT RADAR ECHOS HAVE NOT BEEN ANYTHING TO WRITE
HOME ABOUT. BELIEVE WE WILL SEE SOME MID AFTN TSTM ACTIVITY THOUGH
OVER THE HIGH PLAINS. CURRENT SPEED OF THE TROUGH AXIS SUGGESTS THE
BEST FORCING FOR ASCENT AND MOISTURE WILL SHIFT EAST OF THE CWA BY
ABOUT 22Z...AFTER WHICH TIME TSTMS SHOULD DIMINISH. DESPITE GOOD SFC
HEATING TODAY...LATEST SPC MESOSCALE ANALYSIS INDICATES LESS THAN
1000 J/KG OF SBCAPE. LLVL FLOW OUT OF THE NORTH OR NORTHWEST IS NOT
CONTRIBUTING TO ANY REASONABLE SHEAR PROFILES EITHER SO ANY STRONGER
STORMS SHOULD NOT BE WIDESPREAD THOUGH THEY ARE POSSIBLE. IT SHOULD
BE A QUIET OVERNIGHT WITH AS SUBSIDENCE INCREASES OVER THE CWA. DO
NOT EXPECT FOG DEVELOPMENT TONIGHT WITH UNFAVORABLE LLVL WINDS...BUT
CANNOT RULE IT OUT IN THE PLATTE RIVER VALLEY IF WINDS ARE MORE
SOUTHEAST THAN CURRENTLY PROGGED.
SAT STILL LOOKS TO BE THE WARMEST DAY OF THE PERIOD WITH A VIGOROUS
UPPER-LEVEL TROUGH LURKING OVER THE PACIFIC NW. THERMAL RIDGE AXIS
BUILDS INTO THE CWA WITH NAM H7 TEMPS INCREASING TO 13-14 C FROM THE
LARAMIE RANGE EASTWARD. MOST MOS GUIDANCE SUGGESTS HIGHS IN THE 83
TO 93 DEGREE RANGE OVER THE PLAINS...AND THIS LOOKS REASONABLE GIVEN
THE SYNOPTIC SETUP. THE PROGRESSION OF THE TROUGH AND ASSOCIATED SFC
COLD FRONT APPEARS A BIT SLOWER THAN EARLIER MODELS SUGGESTED...SO
THIS SHOULD DELAY PCPN CHANCES UNTIL MID TO LATE AFTN ON SAT. MIDLVL
QG FIELDS SHOW GOOD ASCENT SPREADING FROM WEST TO EAST AFTER 21Z ON
SAT. THIS OCCURS ALONG WITH LLVL CONVERGENCE ASSOCIATED WITH A
STRONG SFC COLD FRONT MOVING ACROSS THE CWA...SO AM CONFIDENT IN AT
LEAST SCATTERED COVERAGE OF SHOWERS AND TSTMS. INSTABILITY COULD BE
WANING BY THE TIME CONVECTION MOVES FAR ENOUGH EAST...BUT CAN NOT
RULE OUT A STRONG OR LOCALLY SEVERE STORM WITH NAM CAPES AROUND 1500
J/KG BENEATH STEEP MIDLVL LAPSE RATES AND ABOUT 30 KTS OF H5 FLOW.
IT WILL BE BREEZY ON SAT AFTN AND EARLY EVE...ESPECIALLY ALONG AND
WEST OF THE LARAMIE RANGE AS HEIGHT GRADIENTS INCREASE ALOFT AND A
STRONG SFC LOW MOVES ACROSS NORTHERN WY. WSW H7 WINDS AROUND 35 TO
40 KTS SUGGEST STRONGER WINDS OVER THE WIND PRONE AREAS...SO BUMPED
UP GUSTS TO AROUND 45 MPH AT ARL AND BRX.
SHOWERS WILL INCREASE OVERNIGHT THROUGH SUN AM...AND COULD CONTINUE
THROUGH MUCH OF THE AFTN WITH COLDER AIR ALOFT AS THE TROUGH MOVES
OVERHEAD. THE MODELS SHOW H7 TEMPS PLUNGING INTO THE MID SINGLE
DIGITS C ON SUN IN THE POST-FROPA AIR MASS. LOOKING FOR HIGHS TO BE
SOME 10 TO 15 DEGREES COOLER THAN SAT. FLOW ALOFT BRIEFLY BECOMES
MORE ZONAL BY LATE SUN NIGHT...WITH THE ECMWF FINALLY STARTING TO
BACK OFF ON QPF BY ABOUT 06Z MON.
.LONG TERM...(MONDAY THROUGH FRIDAY)
ISSUED AT 150 PM MDT FRI AUG 29 2014
SHORTWAVE TROUGH DRIVEN BY A 100+KT JET STREAK WILL SWEEP ACROSS
THE CWFA ON MONDAY. A QUICK SHOT OF MOISTURE ALONG WITH A WEAK
COLD FRONT WILL PRODUCE PERHAPS SOME AM SHOWER ACTIVITY ACROSS
CARBON AND CONVERSE COUNTIES. BETTER CONVECTIVE CHANCES WILL AWAIT
MONDAY AFTERNOON AS WEAK INSTABILITY IS REALIZED. PROGD SBCAPES
OF AROUND 500 J/KG SUGGEST THAT MOST OF THE CONVECTION WILL BE OF
THE WEAK VARIETY. HOWEVER WITH A STRONG JET OVERHEAD RESULTING IN
AROUND 50 KNOTS OF DEEP LAYER SHEAR...CANT ENTIRELY RULE OUT A FEW
STORMS BECOMING STRONG...ESPECIALLY OVR THE WRN NEBRASKA PANHANDLE
LATE IN THE AFTERNOON. CONVECTIVE CHANCES WILL COME TO AN END
QUICKLY MONDAY EVENING. A DRY ZONAL PATTERN WILL ENSUE ACROSS THE
INTERMOUNTAIN WEST BEHIND MONDAYS DEPARTING SHORTWAVE TROF. THIS
WILL BRING A DRY AND UNSEASONABLY WARM PERIOD INTO THE REGION. H7
TEMPERATURE PROGS INCREASE TO 14-16C...WHICH WILL YIELD DAILY HIGH
TEMPERATURES THAT WILL REACH THE 80S AND LOW 90S EAST OF THE
LARAMIE RANGE...WITH 70S OVR CARBON/ALBANY COUNTIES. THESE ABOVE
AVERAGE TEMPERATURES WILL COMBINE WITH BREEZY CONDITIONS AND AN
ALREADY DRY AIR MASS TO HEIGHTEN FIRE WEATHER CONCERNS WEDNESDAY
AND THURSDAY. LATEST MODEL GUIDANCE CONTINUES TO POINT TO EITHER
DEVELOPING ACROSS ACROSS THE PACNW OR PERHAPS A CUT-OFF JUST OFF
THE CALIFORNIA COAST LATE IN THE WEEK. IN EITHER CASE...SOUTHWEST
FLOW INTO THE ROCKYS WILL PROVIDE A FAVORABLE TRAJECTORY FOR
MOISTURE TO RETURN TO THE CWFA AS EARLY AS THURSDAY NIGHT...BUT
MORE SO FOR FRIDAY. TEMPERATURES WILL ALSO BE A TAD COOLER FRIDAY
AS A THICKER CLOUD CANOPY PREVENTS FULL INSOLATION.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY AFTERNOON)
ISSUED AT 435 PM MDT FRI AUG 29 2014
CONVECTION REALLY DECREASING LATE THIS AFTERNOON AS THE UPPER
SHORTWAVE MOVES OFF TO THE SOUTHEAST. ONLY AIRPORT THAT MAY SEE
SOMETHING LATE TODAY WOULD BE KLAR. CONEVECTION RETURNS SATURDAY
AFTERNOON WITH MOST AIRPORTS SEEING SOME THUNDER BY MID TO LATE
AFTERNOON.
&&
.FIRE WEATHER...
ISSUED AT 150 PM MDT FRI AUG 29 2014
NO CONCERNS FOR CRITICAL FIRE WEATHER IN THE NEAR FUTURE. A STRONG
WEATHER DISTURBANCE AND ASSOCIATED COLD FRONT WILL SWEEP ACROSS THE
AREA ON SAT AFTN THROUGH SUN MORNING. SHOWERS AND TSTMS WILL DEVELOP
FROM WEST TO EAST ACROSS SOUTHEAST WY AND THE WESTERN NE PANHANDLE
DURING THAT TIME. GUSTY WEST-TO-SOUTHWEST WINDS WILL OCCUR ALONG AND
WEST OF THE LARAMIE RANGE ON SAT WITH GUSTS OF 35 TO 45 MPH...BUT
MINIMUM RH VALUES SHOULD REMAIN ABOVE 20 PERCENT. COOLER ON SUN WITH
CONTINUED BREEZY CONDITIONS AND ISOLATED TO SCATTERED SHOWERS AND
WEAK TSTMS.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...HAMMER
LONG TERM...HAHN
AVIATION...CLAYCOMB
FIRE WEATHER...HAMMER
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
200 PM MDT FRI AUG 29 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 150 PM MDT FRI AUG 29 2014
A WELL-DEFINED SHORTWAVE CONTINUES TO SLIDE EASTWARD ACROSS THE CWA
THIS AFTN ALONG THE NORTHERN FRINGE OF BROAD UPPER-LEVEL RIDGING IN
PLACE OVER THE CENTRAL ROCKIES. WATER VAPOR SATELLITE SHOWED THIS
FEATURE OVER NORTHEAST WY AS OF 19Z MOVING QUICKLY TOWARD SOUTHWEST
SD AND THE NORTHERN PANHANDLE. CONVECTIVE CHANCES ARE THE MAIN ISSUE
IN THE NEAR TERM. ASIDE FROM MOUNTAIN CONVECTION...SHOWER AND TSTM
CHANCES WILL BE ASSOCIATED WITH LARGER SCALE FORCING IN ADVANCE OF
THE AFOREMENTIONED WAVE. THE NAM IS STILL THE MOST BULLISH WITH QPF
OVER OUR NORTHEAST ZONES WHILE THE HRRR COMPOSITE REFLECTIVITY SHOWS
FAIRLY MODEST CONVECTIVE COVERAGE. CONFIDENCE IS FAIRLY LOW IN JUST
HOW WIDESPREAD THINGS WILL BE TODAY GIVEN WEAK SUBSIDENCE BENEATH
THE RIDGE...AND RECENT RADAR ECHOS HAVE NOT BEEN ANYTHING TO WRITE
HOME ABOUT. BELIEVE WE WILL SEE SOME MID AFTN TSTM ACTIVITY THOUGH
OVER THE HIGH PLAINS. CURRENT SPEED OF THE TROUGH AXIS SUGGESTS THE
BEST FORCING FOR ASCENT AND MOISTURE WILL SHIFT EAST OF THE CWA BY
ABOUT 22Z...AFTER WHICH TIME TSTMS SHOULD DIMINISH. DESPITE GOOD SFC
HEATING TODAY...LATEST SPC MESOSCALE ANALYSIS INDICATES LESS THAN
1000 J/KG OF SBCAPE. LLVL FLOW OUT OF THE NORTH OR NORTHWEST IS NOT
CONTRIBUTING TO ANY REASONABLE SHEAR PROFILES EITHER SO ANY STRONGER
STORMS SHOULD NOT BE WIDESPREAD THOUGH THEY ARE POSSIBLE. IT SHOULD
BE A QUIET OVERNIGHT WITH AS SUBSIDENCE INCREASES OVER THE CWA. DO
NOT EXPECT FOG DEVELOPMENT TONIGHT WITH UNFAVORABLE LLVL WINDS...BUT
CANNOT RULE IT OUT IN THE PLATTE RIVER VALLEY IF WINDS ARE MORE
SOUTHEAST THAN CURRENTLY PROGGED.
SAT STILL LOOKS TO BE THE WARMEST DAY OF THE PERIOD WITH A VIGOROUS
UPPER-LEVEL TROUGH LURKING OVER THE PACIFIC NW. THERMAL RIDGE AXIS
BUILDS INTO THE CWA WITH NAM H7 TEMPS INCREASING TO 13-14 C FROM THE
LARAMIE RANGE EASTWARD. MOST MOS GUIDANCE SUGGESTS HIGHS IN THE 83
TO 93 DEGREE RANGE OVER THE PLAINS...AND THIS LOOKS REASONABLE GIVEN
THE SYNOPTIC SETUP. THE PROGRESSION OF THE TROUGH AND ASSOCIATED SFC
COLD FRONT APPEARS A BIT SLOWER THAN EARLIER MODELS SUGGESTED...SO
THIS SHOULD DELAY PCPN CHANCES UNTIL MID TO LATE AFTN ON SAT. MIDLVL
QG FIELDS SHOW GOOD ASCENT SPREADING FROM WEST TO EAST AFTER 21Z ON
SAT. THIS OCCURS ALONG WITH LLVL CONVERGENCE ASSOCIATED WITH A
STRONG SFC COLD FRONT MOVING ACROSS THE CWA...SO AM CONFIDENT IN AT
LEAST SCATTERED COVERAGE OF SHOWERS AND TSTMS. INSTABILITY COULD BE
WANING BY THE TIME CONVECTION MOVES FAR ENOUGH EAST...BUT CAN NOT
RULE OUT A STRONG OR LOCALLY SEVERE STORM WITH NAM CAPES AROUND 1500
J/KG BENEATH STEEP MIDLVL LAPSE RATES AND ABOUT 30 KTS OF H5 FLOW.
IT WILL BE BREEZY ON SAT AFTN AND EARLY EVE...ESPECIALLY ALONG AND
WEST OF THE LARAMIE RANGE AS HEIGHT GRADIENTS INCREASE ALOFT AND A
STRONG SFC LOW MOVES ACROSS NORTHERN WY. WSW H7 WINDS AROUND 35 TO
40 KTS SUGGEST STRONGER WINDS OVER THE WIND PRONE AREAS...SO BUMPED
UP GUSTS TO AROUND 45 MPH AT ARL AND BRX.
SHOWERS WILL INCREASE OVERNIGHT THROUGH SUN AM...AND COULD CONTINUE
THROUGH MUCH OF THE AFTN WITH COLDER AIR ALOFT AS THE TROUGH MOVES
OVERHEAD. THE MODELS SHOW H7 TEMPS PLUNGING INTO THE MID SINGLE
DIGITS C ON SUN IN THE POST-FROPA AIR MASS. LOOKING FOR HIGHS TO BE
SOME 10 TO 15 DEGREES COOLER THAN SAT. FLOW ALOFT BRIEFLY BECOMES
MORE ZONAL BY LATE SUN NIGHT...WITH THE ECMWF FINALLY STARTING TO
BACK OFF ON QPF BY ABOUT 06Z MON.
.LONG TERM...(MONDAY THROUGH FRIDAY)
ISSUED AT 150 PM MDT FRI AUG 29 2014
SHORTWAVE TROUGH DRIVEN BY A 100+KT JET STREAK WILL SWEEP ACROSS
THE CWFA ON MONDAY. A QUICK SHOT OF MOISTURE ALONG WITH A WEAK
COLD FRONT WILL PRODUCE PERHAPS SOME AM SHOWER ACTIVITY ACROSS
CARBON AND CONVERSE COUNTIES. BETTER CONVECTIVE CHANCES WILL AWAIT
MONDAY AFTERNOON AS WEAK INSTABILITY IS REALIZED. PROGD SBCAPES
OF AROUND 500 J/KG SUGGEST THAT MOST OF THE CONVECTION WILL BE OF
THE WEAK VARIETY. HOWEVER WITH A STRONG JET OVERHEAD RESULTING IN
AROUND 50 KNOTS OF DEEP LAYER SHEAR...CANT ENTIRELY RULE OUT A FEW
STORMS BECOMING STRONG...ESPECIALLY OVR THE WRN NEBRASKA PANHANDLE
LATE IN THE AFTERNOON. CONVECTIVE CHANCES WILL COME TO AN END
QUICKLY MONDAY EVENING. A DRY ZONAL PATTERN WILL ENSUE ACROSS THE
INTERMOUNTAIN WEST BEHIND MONDAYS DEPARTING SHORTWAVE TROF. THIS
WILL BRING A DRY AND UNSEASONABLY WARM PERIOD INTO THE REGION. H7
TEMPERATURE PROGS INCREASE TO 14-16C...WHICH WILL YIELD DAILY HIGH
TEMPERATURES THAT WILL REACH THE 80S AND LOW 90S EAST OF THE
LARAMIE RANGE...WITH 70S OVR CARBON/ALBANY COUNTIES. THESE ABOVE
AVERAGE TEMPERATURES WILL COMBINE WITH BREEZY CONDITIONS AND AN
ALREADY DRY AIR MASS TO HEIGHTEN FIRE WEATHER CONCERNS WEDNESDAY
AND THURSDAY. LATEST MODEL GUIDANCE CONTINUES TO POINT TO EITHER
DEVELOPING ACROSS ACROSS THE PACNW OR PERHAPS A CUT-OFF JUST OFF
THE CALIFORNIA COAST LATE IN THE WEEK. IN EITHER CASE...SOUTHWEST
FLOW INTO THE ROCKYS WILL PROVIDE A FAVORABLE TRAJECTORY FOR
MOISTURE TO RETURN TO THE CWFA AS EARLY AS THURSDAY NIGHT...BUT
MORE SO FOR FRIDAY. TEMPERATURES WILL ALSO BE A TAD COOLER FRIDAY
AS A THICKER CLOUD CANOPY PREVENTS FULL INSOLATION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY MORNING)
ISSUED AT 1200 PM MDT FRI AUG 29 2014
CONVECTIVE TIMING AND STRENGTH AGAIN THE MAIN FOCUS FOR THIS SET
OF TAFS. RADAR SHOWS LINE OF CONVECTIVE DEVELOPMENT EXTENDING FROM
AROUND KCDR SW TO NR KLAR AS OF NOON. THIS WILL BE THE AREA TO
WATCH THIS AFTERNOON AS THIS DISTURBANCE AND BOUNDARY SHIFTS
SOUTHEAST ACROSS THE AREA. FOR NOW HAVE KEPT AND ADDED VCTS TO ALL
LOCATIONS THIS AFTERNOON WITH THE EXCEPTION OF KRWL...WHICH ARE
ALREADY WEST OF THE DISTURBANCE. ANY SHOWERS OR THUNDERSTORMS THAT
DO DEVELOP SHOULD SLIDE EAST OF THE AREA BY BETWEEN 22-24Z...
LEAVING VFR CONDITIONS AS SKIES CLEAR.
&&
.FIRE WEATHER...
ISSUED AT 150 PM MDT FRI AUG 29 2014
NO CONCERNS FOR CRITICAL FIRE WEATHER IN THE NEAR FUTURE. A STRONG
WEATHER DISTURBANCE AND ASSOCIATED COLD FRONT WILL SWEEP ACROSS THE
AREA ON SAT AFTN THROUGH SUN MORNING. SHOWERS AND TSTMS WILL DEVELOP
FROM WEST TO EAST ACROSS SOUTHEAST WY AND THE WESTERN NE PANHANDLE
DURING THAT TIME. GUSTY WEST-TO-SOUTHWEST WINDS WILL OCCUR ALONG AND
WEST OF THE LARAMIE RANGE ON SAT WITH GUSTS OF 35 TO 45 MPH...BUT
MINIMUM RH VALUES SHOULD REMAIN ABOVE 20 PERCENT. COOLER ON SUN WITH
CONTINUED BREEZY CONDITIONS AND ISOLATED TO SCATTERED SHOWERS AND
WEAK TSTMS.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...HAMMER
LONG TERM...HAHN
AVIATION...HAHN
FIRE WEATHER...HAMMER
AREA FORECAST DISCUSSION
NWS ALBANY NY
224 AM EDT SUN AUG 31 2014
.SYNOPSIS...
A SLOW MOVING COLD FRONT WILL BRING SHOWERS AND
THUNDERSTORMS TODAY...SOME POSSIBLY WITH HEAVY RAINFALL. WEAK HIGH
PRESSURE WILL BUILD IN LABOR DAY. IT WILL BE VERY WARM AND HUMID AND
MAINLY RAIN-FREE...BUT AN ADDITIONAL THUNDERSTORM CANNOT BE RULED
OUT. ANOTHER COLD FRONT IS EXPECTED TO BRING A CHANCE FOR SHOWERS
AND THUNDERSTORMS TUESDAY AND TUESDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1245 AM EDT...RADAR INDICATED THAT SHOWERS AND THUNDERSTORMS
WERE STILL HAVING A DIFFICULT TIME MAKING INTO HERKIMER COUNTY...AS
THEY WERE MAINLY TRACKING TO THE NORTHWEST OF NORTHERN HERKIMER
COUNTY...ALONG THE TUG HILL PLATEAU.
BOTH THE LATEST RUC13 AND HRRR NOW KEEP MOST OF THE ACTIVITY
CONFINED TO OUR NORTHWEST AREAS OVERNIGHT SO WE DECIDED TO TRIM BACK
THE POPS EVEN MORE COMPARED TO THE LAST UPDATE.
THE IFR 11U-3.9U IFR SATELLITE PICTURES INDICATED STRATUS SLOWLY
OVERSPREADING THE REGION FROM THE SOUTH...WHILE MID AND HIGH CLOUDS
WERE WORKING IN FROM THE WEST.
TEMPERATURES WERE STILL MILD...GENERALLY IN THE 60S THANKS TO THE
INCREASING CLOUDS AND A PERSISTENT SOUTHERLY BREEZE.
FOR THE REST OF THE OVERNIGHT...LOOK FOR SCATTERED SHOWERS AND
PERHAPS A RUMBLE OF THUNDER (THE SHOWALTER INDICES WERE GENERALLY
JUST ABOVE 0 SO MUCH INSTABILITY)...OVER MAINLY OUR PORTION OF THE
ADIRONDACK PARK. EVERYONE ELSE SHOULD REMAIN DRY WITH INCREASING
CLOUDS.
NO CHANGES TO OVERNIGHT LOWS...LOOK FOR THEM TO ONLY DROP A POINT OR
TWO MORE...GENERALLY STAYING IN THE 60S ALL NIGHT ALONG. THE
SOUTHERLY BREEZE WILL PERSIST 5 TO 15 MPH.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/...
STILL SOME QUESTION AS TO HOW MUCH CLOUD COVER WILL BE OVER THE
REGION TOMORROW. SOUTHWEST BOUNDARY LAYER FLOW AND A LOOSENING
BOUNDARY LAYER THERMAL GRADIENT SHOULD PROMOTE SOME BREAKS IN
CLOUD COVER. THERE SHOULD ALSO BE BREAKS IN THE LEFTOVER
CONVECTIVE DEBRIS FROM CONVECTION IN THE GREAT LAKES AND WESTERN
NY/PA. CLOUD COVER CURRENTLY UPSTREAM IN THE OH VALLEY AND GREAT
LAKES IS SCATTERED TO BROKEN. SO WITH THE PROSPECTS FOR AT LEAST
SOME INTERVALS OF SUN...WITH RAPIDLY WARMING BOUNDARY LAYER
TEMPERATURES...HIGHS SOLIDLY IN THE 80S SUNDAY...BUT UPPER 70S
SOUTHERN ADIRONDACKS WHERE SHOWERS AND THUNDERSTORMS SHOULD AFFECT
EARLIER IN THE DAY.
UPPER DYNAMICS...ALONG WITH A LITTLE LOW LEVEL JET SEGMENT TRACKS
THROUGH THE REGION SUNDAY AND SUNDAY NIGHT. DEEP MOISTURE SEEN IN
THE SATELLITE DERIVED SOUNDER IMAGERY OF PWAT...IS SURGING NORTH
FROM THE MS/TN VALLEY. SO...COVERAGE OF SHOWERS AND SCATTERED
THUNDERSTORMS SHOULD INCREASE TO LIKELY IN THE AFTERNOON IN MOST
AREAS. LOCALLY HEAVY RAIN IS POSSIBLE AND WILL ADDRESS IN
HAZARDOUS WEATHER OUTLOOK...BUT NO WIDESPREAD OR HIGH IMPACT FLOOD
THREAT EXPECTED.
WEAK COLD FRONT EXITS SUNDAY NIGHT WITH JUST SOME LINGERING
SCATTERED SHOWERS AND THUNDERSTORMS...WITH THE BEST COVERAGE IN
THE MID HUDSON VALLEY...BERKSHIRES AND NW CT SUNDAY EVENING. SOME
QUESTION AS TO HOW FAR SOUTH THE WEAK LOW LEVEL BOUNDARY GETS...SO
SCATTERED SHOWERS AND THUNDERSTORMS COULD LINGER THROUGH MUCH OF
MONDAY IN THE MID HUDSON VALLEY AND NW CT...BUT JUST SCATTERED...
WITH ISOLATED AFTERNOON ACTIVITY ELSEWHERE. STILL...SOME PERIODS
OF SUNSHINE EXPECTED MONDAY...WITH PERHAPS MORE CLOUDS THAN SUN IN
THE MID HUDSON VALLEY AND NW CT. HIGHS MONDAY SOLIDLY IN THE 80S.
THERE COULD BE A LULL IN THE SHOWER AND THUNDERSTORM ACTIVITY
MONDAY NIGHT WITH PARTIAL CLEARING...BUT DEW POINTS ARE NOT
EXPECTED TO DROP MUCH IF ANY...SO LOWS MONDAY NIGHT IN THE 60S.
ANOTHER COLD FRONT APPROACHES TUESDAY...WITH A BIT BETTER BOUNDARY
LAYER FRONTOGENESIS AND THERMAL GRADIENT TRACKING TOWARD THE
REGION. CURRENT CONSENSUS ON TIMING SUGGESTS SOME SUNSHINE AND
DAYTIME HEATING AT LEAST TUESDAY MORNING...WITH THE LEADING EDGE
OF SCATTERED SHOWERS AND THUNDERSTORMS APPROACHING WESTERN AREAS
MIDDAY OR EARLY AFTERNOON TUESDAY...THEN AFFECTING THE REST OF THE
REGION THROUGH THE AFTERNOON. HIGHS TUESDAY SOLIDLY IN THE 80S.
THUNDERSTORMS TUESDAY COULD BE STRONG BASED ON THE POTENTIAL
INSTABILITY...THERMAL GRADIENT FORCING AND BOUNDARY LAYER WINDS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
MIDWEEK THROUGH THE END OF THE WORK WEEK WILL FEATURE DRY CONDITIONS
AS HIGH PRESSURE MOVES OVER THE FORECAST AREA BEHIND A COLD FRONT.
HOWEVER...A COLD FRONT ON SATURDAY WILL BRING A SHOWERY START FOR
THE BEGINNING OF THE WEEKEND.
TEMPERATURES WILL AVERAGE A FEW DEGREES ABOVE NORMAL...WITH HIGHS
FROM AROUND 70 DEGREES...TO THE LOWER AND MID 80S WEDNESDAY THROUGH
FRIDAY. SATURDAY WILL BE COOLER WITH HIGHS FROM THE MID 60S TO
AROUND 809 DEGREES.
NIGHTTIME LOWS WILL BE IN THE MID 50S TO UPPER 60S RANGE JUST PRIOR
TO THE COLD FRONT TUESDAY NIGHT. WEDNESDAY NIGHT LOWS WILL RANGE
FROM AROUND 50 DEGREES IN THE WESTERN ADIRONDACKS...TO NEAR 60
DEGREES DOWN THE HUDSON VALLEY. THEN READINGS SLOWLY BOUNCE BACK...
WITH LOWS FROM MAINLY THE LOWER AND MID 50S IN THE MOUNTAINS...TO
THE LOWER 60S DOWN THE HUDSON VALLEY.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AS OF 200 AM...CIGS AT THE KGFL/KALB/KPOU TAF SITES ARE VERY CLOSE
TO THE MVFR/VFR CUTOFF OF 3000 FEET...WITH KALB STILL ONLY SCT AT
3300 FEET. AT KPSF CIGS ARE AROUND 1500 FEET. EXPECT MAINLY MVFR
CIGS AT ALL THE TAF SITES THROUGH AROUND 15Z...WITH OCCASIONAL IFR
CIGS AT KPSF. AFTER 15Z CIGS SHOULD RISE TO MAINLY VFR AT
KGFL/KALB/KPOU...AND MVFR AT KPSF. VCSH HAS BEEN INCLUDED AT ALL THE
TAF SITES AFTER 15Z. THE MAIN BAND OF MOISTURE ASSOCIATED WITH THE
FRONTAL BOUNDARY AND UPPER LEVEL TROF WILL MOVE ACROSS THE TAF SITES
LATER SUNDAY AFTERNOON AND EVENING. HAVE FORECAST MVFR CIGS/VSBYS AT
ALL THE TAFS SITES AFTER 19Z/20Z AS WIDESPREAD SHOWERS MOVE
IN...WITH A PROB 30 GROUP GENERALLY BETWEEN 19Z AND 01Z FOR A CHANCE
OF TSTMS WITH MVFR CONDITIONS. THE WIDESPREAD SHOWERS WILL LIKELY
END BY AROUND 01Z/02Z AT THE TAF SITES...BUT EXPECT MVFR CIGS/VSBYS
TO LINGER DUE TO FOG AND STRATUS STILL OVER THE REGION.
WINDS WILL BE CALM OR SOUTH AT 8 KTS OR LESS THROUGH THE REST OF
TONIGHT...THEN SOUTH OR SOUTHWEST AT 7 TO 10 KTS ON SUNDAY AND
SUNDAY EVENING...BECOMING 5 KTS OR LESS AFTER 02Z SUNDAY NIGHT.
OUTLOOK...
LATE SUNDAY NIGHT: MODERATE OPERATIONAL IMPACT. SCATTERED
SHRA...TSRA.
LABOR DAY: LOW OPERATIONAL IMPACT. ISOLATED SHRA...TSRA.
MONDAY NIGHT: LOW OPERATIONAL IMPACT. ISOLATED SHRA...TSRA.
TUESDAY: MODERATE OPERATIONAL IMPACT. SCATTERED SHRA...TSRA.
TUESDAY NIGHT: MODERATE OPERATIONAL IMPACT. SCATTERED SHRA...TSRA.
WEDNESDAY: NO OPERATIONAL IMPACT. NO SIG WX.
WEDNESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
THURSDAY: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.FIRE WEATHER...
LATE TONIGHT INTO SUNDAY A SLOW MOVING COLD FRONT WILL BRING A
ROUND OF SHOWERS AND THUNDERSTORMS...SOME POSSIBLY WITH HEAVY
RAINFALL. WEAK HIGH PRESSURE WILL BUILD IN LABOR DAY. IT WILL BE
VERY WARM HUMID AND MAINLY RAIN-FREE...BUT AN ADDITIONAL
THUNDERSTORM CANNOT BE RULED OUT. ANOTHER COLD FRONT IS
EXPECTED TO BRING A CHANCE FOR SHOWERS AND THUNDERSTORMS TUESDAY
AND TUESDAY NIGHT.
MINIMUM RH VALUES SHOULD BE BETWEEN 65 TO 75 PERCENT SUNDAY ASS
COVERAGE OF SHOWERS AND THUNDERSTORMS INCREASES. MINIMUM RH VALUES
MONDAY SHOULD BE 55 TO 65 PERCENT. MAXIMUM RH VALUES TONIGHT AND
TOMORROW NIGHT ARE EXPECTED TO BE 80 TO 100 PERCENT WITH SOME DEW
FORMATION.
THE SURFACE WIND BE SOUTH TO SOUTHWEST AT 15 MPH OR LESS TONIGHT
THROUGH SUNDAY NIGHT...THEN BECOME WEST TO SOUTHWEST MONDAY.
&&
.HYDROLOGY...
SHOWERS AND THUNDERSTORMS WILL DEVELOP LATE TONIGHT AND
ESPECIALLY SUNDAY INTO SUNDAY EVENING. AVERAGE BASIN RAINFALLS
LOOK TO GENERALLY BE UNDER AN INCH SO AT THIS POINT...MAIN STREAM
RIVERS WILL GENERALLY SEE LITTLE OR NO RISES.
HOWEVER...WITH PWAT VALUES FORECAST TO INCREASE TO 2 INCHES...ANY
THUNDERSTORM COULD CONTAIN LOCALLY HEAVY RAINFALL EASILY EXCEEDING
AN INCH. ANY TRAINING THUNDERSTORMS COULD RESULT LOCALIZED PONDING
OF WATER IN AREAS OF POOR DRAINAGE.
ADDITIONAL THUNDERSTORMS ON LABOR DAY LOOK ISOLATED AND GENERALLY
NOT EXPECTED TO PRODUCE ADDITIONAL HYDRO PROBLEMS.
MORE SHOWERS AND THUNDERSTORMS ARE POSSIBLE LATE TUESDAY INTO
WEDNESDAY AS A STRONGER COLD FRONT ARRIVES.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...SND/HWJIV/NAS
NEAR TERM...HWJIV
SHORT TERM...NAS
LONG TERM...ELH
AVIATION...GJM
FIRE WEATHER...NAS
HYDROLOGY...NAS
AREA FORECAST DISCUSSION
NWS ALBANY NY
1243 AM EDT SUN AUG 31 2014
.SYNOPSIS...
A SLOW MOVING COLD FRONT WILL BRING SHOWERS AND
THUNDERSTORMS TODAY...SOME POSSIBLY WITH HEAVY RAINFALL. WEAK HIGH
PRESSURE WILL BUILD IN LABOR DAY. IT WILL BE VERY WARM AND HUMID AND
MAINLY RAIN-FREE...BUT AN ADDITIONAL THUNDERSTORM CANNOT BE RULED
OUT. ANOTHER COLD FRONT IS EXPECTED TO BRING A CHANCE FOR SHOWERS
AND THUNDERSTORMS TUESDAY AND TUESDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1245 AM EDT...RADAR INDICATED THAT SHOWERS AND THUNDERSTORMS
WERE STILL HAVING A DIFFICULT TIME MAKING INTO HERKIMER COUNTY...AS
THEY WERE MAINLY TRACKING TO THE NORTHWEST OF NORTHERN HERKIMER
COUNTY...ALONG THE TUG HILL PLATEAU.
BOTH THE LATEST RUC13 AND HRRR NOW KEEP MOST OF THE ACTIVITY
CONFINED TO OUR NORTHWEST AREAS OVERNIGHT SO WE DECIDED TO TRIM BACK
THE POPS EVEN MORE COMPARED TO THE LAST UPDATE.
THE IFR 11U-3.9U IFR SATELLITE PICTURES INDICATED STRATUS SLOWLY
OVERSPREADING THE REGION FROM THE SOUTH...WHILE MID AND HIGH CLOUDS
WERE WORKING IN FROM THE WEST.
TEMPERATURES WERE STILL MILD...GENERALLY IN THE 60S THANKS TO THE
INCREASING CLOUDS AND A PERSISTENT SOUTHERLY BREEZE.
FOR THE REST OF THE OVERNIGHT...LOOK FOR SCATTERED SHOWERS AND
PERHAPS A RUMBLE OF THUNDER (THE SHOWALTER INDICES WERE GENERALLY
JUST ABOVE 0 SO MUCH INSTABILITY)...OVER MAINLY OUR PORTION OF THE
ADIRONDACK PARK. EVERYONE ELSE SHOULD REMAIN DRY WITH INCREASING
CLOUDS.
NO CHANGES TO OVERNIGHT LOWS...LOOK FOR THEM TO ONLY DROP A POINT OR
TWO MORE...GENERALLY STAYING IN THE 60S ALL NIGHT ALONG. THE
SOUTHERLY BREEZE WILL PERSIST 5 TO 15 MPH.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/...
STILL SOME QUESTION AS TO HOW MUCH CLOUD COVER WILL BE OVER THE
REGION TOMORROW. SOUTHWEST BOUNDARY LAYER FLOW AND A LOOSENING
BOUNDARY LAYER THERMAL GRADIENT SHOULD PROMOTE SOME BREAKS IN
CLOUD COVER. THERE SHOULD ALSO BE BREAKS IN THE LEFTOVER
CONVECTIVE DEBRIS FROM CONVECTION IN THE GREAT LAKES AND WESTERN
NY/PA. CLOUD COVER CURRENTLY UPSTREAM IN THE OH VALLEY AND GREAT
LAKES IS SCATTERED TO BROKEN. SO WITH THE PROSPECTS FOR AT LEAST
SOME INTERVALS OF SUN...WITH RAPIDLY WARMING BOUNDARY LAYER
TEMPERATURES...HIGHS SOLIDLY IN THE 80S SUNDAY...BUT UPPER 70S
SOUTHERN ADIRONDACKS WHERE SHOWERS AND THUNDERSTORMS SHOULD AFFECT
EARLIER IN THE DAY.
UPPER DYNAMICS...ALONG WITH A LITTLE LOW LEVEL JET SEGMENT TRACKS
THROUGH THE REGION SUNDAY AND SUNDAY NIGHT. DEEP MOISTURE SEEN IN
THE SATELLITE DERIVED SOUNDER IMAGERY OF PWAT...IS SURGING NORTH
FROM THE MS/TN VALLEY. SO...COVERAGE OF SHOWERS AND SCATTERED
THUNDERSTORMS SHOULD INCREASE TO LIKELY IN THE AFTERNOON IN MOST
AREAS. LOCALLY HEAVY RAIN IS POSSIBLE AND WILL ADDRESS IN
HAZARDOUS WEATHER OUTLOOK...BUT NO WIDESPREAD OR HIGH IMPACT FLOOD
THREAT EXPECTED.
WEAK COLD FRONT EXITS SUNDAY NIGHT WITH JUST SOME LINGERING
SCATTERED SHOWERS AND THUNDERSTORMS...WITH THE BEST COVERAGE IN
THE MID HUDSON VALLEY...BERKSHIRES AND NW CT SUNDAY EVENING. SOME
QUESTION AS TO HOW FAR SOUTH THE WEAK LOW LEVEL BOUNDARY GETS...SO
SCATTERED SHOWERS AND THUNDERSTORMS COULD LINGER THROUGH MUCH OF
MONDAY IN THE MID HUDSON VALLEY AND NW CT...BUT JUST SCATTERED...
WITH ISOLATED AFTERNOON ACTIVITY ELSEWHERE. STILL...SOME PERIODS
OF SUNSHINE EXPECTED MONDAY...WITH PERHAPS MORE CLOUDS THAN SUN IN
THE MID HUDSON VALLEY AND NW CT. HIGHS MONDAY SOLIDLY IN THE 80S.
THERE COULD BE A LULL IN THE SHOWER AND THUNDERSTORM ACTIVITY
MONDAY NIGHT WITH PARTIAL CLEARING...BUT DEW POINTS ARE NOT
EXPECTED TO DROP MUCH IF ANY...SO LOWS MONDAY NIGHT IN THE 60S.
ANOTHER COLD FRONT APPROACHES TUESDAY...WITH A BIT BETTER BOUNDARY
LAYER FRONTOGENESIS AND THERMAL GRADIENT TRACKING TOWARD THE
REGION. CURRENT CONSENSUS ON TIMING SUGGESTS SOME SUNSHINE AND
DAYTIME HEATING AT LEAST TUESDAY MORNING...WITH THE LEADING EDGE
OF SCATTERED SHOWERS AND THUNDERSTORMS APPROACHING WESTERN AREAS
MIDDAY OR EARLY AFTERNOON TUESDAY...THEN AFFECTING THE REST OF THE
REGION THROUGH THE AFTERNOON. HIGHS TUESDAY SOLIDLY IN THE 80S.
THUNDERSTORMS TUESDAY COULD BE STRONG BASED ON THE POTENTIAL
INSTABILITY...THERMAL GRADIENT FORCING AND BOUNDARY LAYER WINDS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
MIDWEEK THROUGH THE END OF THE WORK WEEK WILL FEATURE DRY CONDITIONS
AS HIGH PRESSURE MOVES OVER THE FORECAST AREA BEHIND A COLD FRONT.
HOWEVER...A COLD FRONT ON SATURDAY WILL BRING A SHOWERY START FOR
THE BEGINNING OF THE WEEKEND.
TEMPERATURES WILL AVERAGE A FEW DEGREES ABOVE NORMAL...WITH HIGHS
FROM AROUND 70 DEGREES...TO THE LOWER AND MID 80S WEDNESDAY THROUGH
FRIDAY. SATURDAY WILL BE COOLER WITH HIGHS FROM THE MID 60S TO
AROUND 809 DEGREES.
NIGHTTIME LOWS WILL BE IN THE MID 50S TO UPPER 60S RANGE JUST PRIOR
TO THE COLD FRONT TUESDAY NIGHT. WEDNESDAY NIGHT LOWS WILL RANGE
FROM AROUND 50 DEGREES IN THE WESTERN ADIRONDACKS...TO NEAR 60
DEGREES DOWN THE HUDSON VALLEY. THEN READINGS SLOWLY BOUNCE BACK...
WITH LOWS FROM MAINLY THE LOWER AND MID 50S IN THE MOUNTAINS...TO
THE LOWER 60S DOWN THE HUDSON VALLEY.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS PREVAILING ACROSS THE TERMINALS THIS
AFTERNOON...HOWEVER AN EXPANSIVE AREA OF STRATUS CLOUDS IS
NOTICEABLY CREEPING TOWARDS THE AREA FROM PA/NJ INTO THE CATSKILLS
OF NY...COURTESY OF LOW LEVEL MOISTURE INCREASING WITH A SOUTH TO
SOUTHWEST FLOW. FOR NOW...MOST OF THE CIGS ARE IN VFR RANGE
ALTHOUGH MVFR CIGS HAVE BEEN NOTED ACROSS SOME HIGHER TERRAIN
AREAS. WILL MENTION SCT CLOUDS EARLY WITH CIGS DEVELOPING LATER
THIS AFTERNOON OR EARLY EVENING...FROM SOUTHWEST TO NORTHEAST
ACROSS THE AREA. CIGS EXPECTED TO LOWER TO MVFR RANGE THIS
EVENING...ESPECIALLY LATER THIS EVENING AS LOW LEVEL DEWPOINTS
CONTINUE TO RISE. OVERNIGHT MAINLY MVFR CONDITIONS EXPECTED WITH
OVC CIGS AND SOME MIST. HOWEVER...THERE IS A CHANCE OF SOME
OCCASIONAL IFR AT KPSF BUT CONFIDENCE NOT GREAT ENOUGH TO MENTION
IN TAF AT THIS TIME.
CIGS WILL ONLY SLOWLY RISE ON SUNDAY...BUT SHOULD STILL GENERALLY
REMAIN IN MVFR RANGE THROUGH 18Z SUNDAY UNTIL LATER IN THE DAY. A
COLD FRONT WILL APPROACH FROM THE WEST BRINGING A THREAT OF MAINLY
AFTERNOON RAIN SHOWERS/THUNDERSTORMS. WILL MENTION VCSH IN KGFL/KALB
TAF PRIOR TO 18Z.
WINDS WILL BE SOUTHERLY AROUND 6-12 KT WITH SOME OCCASIONAL HIGHER
GUSTS. WIND SPEEDS WILL DECREASE TO AROUND 3-8 KT AFTER DARK.
WINDS WILL GENERALLY BE SOUTH-SOUTHWEST AROUND 5-10 KT ON SUNDAY.
OUTLOOK...
SUNDAY NIGHT: MODERATE OPERATIONAL IMPACT. SCATTERED SHRA...TSRA.
LABOR DAY: LOW OPERATIONAL IMPACT. ISOLATED SHRA...TSRA.
MONDAY NIGHT: LOW OPERATIONAL IMPACT. ISOLATED SHRA...TSRA.
TUESDAY: MODERATE OPERATIONAL IMPACT. SCATTERED SHRA...TSRA.
TUESDAY NIGHT: MODERATE OPERATIONAL IMPACT. SCATTERED SHRA...TSRA.
WEDNESDAY: NO OPERATIONAL IMPACT. NO SIG WX.
WEDNESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
THURSDAY: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.FIRE WEATHER...
LATE TONIGHT INTO SUNDAY A SLOW MOVING COLD FRONT WILL BRING A
ROUND OF SHOWERS AND THUNDERSTORMS...SOME POSSIBLY WITH HEAVY
RAINFALL. WEAK HIGH PRESSURE WILL BUILD IN LABOR DAY. IT WILL BE
VERY WARM HUMID AND MAINLY RAIN-FREE...BUT AN ADDITIONAL
THUNDERSTORM CANNOT BE RULED OUT. ANOTHER COLD FRONT IS
EXPECTED TO BRING A CHANCE FOR SHOWERS AND THUNDERSTORMS TUESDAY
AND TUESDAY NIGHT.
MINIMUM RH VALUES SHOULD BE BETWEEN 65 TO 75 PERCENT SUNDAY ASS
COVERAGE OF SHOWERS AND THUNDERSTORMS INCREASES. MINIMUM RH VALUES
MONDAY SHOULD BE 55 TO 65 PERCENT. MAXIMUM RH VALUES TONIGHT AND
TOMORROW NIGHT ARE EXPECTED TO BE 80 TO 100 PERCENT WITH SOME DEW
FORMATION.
THE SURFACE WIND BE SOUTH TO SOUTHWEST AT 15 MPH OR LESS TONIGHT
THROUGH SUNDAY NIGHT...THEN BECOME WEST TO SOUTHWEST MONDAY.
&&
.HYDROLOGY...
SHOWERS AND THUNDERSTORMS WILL DEVELOP LATE TONIGHT AND
ESPECIALLY SUNDAY INTO SUNDAY EVENING. AVERAGE BASIN RAINFALLS
LOOK TO GENERALLY BE UNDER AN INCH SO AT THIS POINT...MAIN STREAM
RIVERS WILL GENERALLY SEE LITTLE OR NO RISES.
HOWEVER...WITH PWAT VALUES FORECAST TO INCREASE TO 2 INCHES...ANY
THUNDERSTORM COULD CONTAIN LOCALLY HEAVY RAINFALL EASILY EXCEEDING
AN INCH. ANY TRAINING THUNDERSTORMS COULD RESULT LOCALIZED PONDING
OF WATER IN AREAS OF POOR DRAINAGE.
ADDITIONAL THUNDERSTORMS ON LABOR DAY LOOK ISOLATED AND GENERALLY
NOT EXPECTED TO PRODUCE ADDITIONAL HYDRO PROBLEMS.
MORE SHOWERS AND THUNDERSTORMS ARE POSSIBLE LATE TUESDAY INTO
WEDNESDAY AS A STRONGER COLD FRONT ARRIVES.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...SND/HWJIV/NAS
NEAR TERM...HWJIV
SHORT TERM...NAS
LONG TERM...ELH
AVIATION...JPV
FIRE WEATHER...NAS
HYDROLOGY...NAS
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
303 AM CDT SUN AUG 31 2014
.DISCUSSION...
221 PM CDT
SYNOPSIS...SCATTERED THUNDERSTORMS ARE POSSIBLE NW OF I-55 WHILE A
LINE OF STORMS WILL IMPACT AREAS ALONG AND EAST OF I-55 THROUGH THIS
EVENING. TOMORROW WILL BE DRY BUT UNSETTLED WEATHER RETURNS MONDAY
WITH MULTIPLE CHANCES FOR THUNDERSTORMS. SEVERE STORMS ARE POSSIBLE
MONDAY. TEMPERATURES WILL BE ABOVE NORMAL THROUGH THE PERIOD WITH A
COUPLE DAYS GETTING INTO THE MID 80S.
THROUGH TONIGHT...
AN UPPER LEVEL TROUGH IS OVER THE UPPER MISSISSIPPI RIVER VALLEY AND
IT WILL PASS OVER THE REGION THROUGH THIS EVENING. A SURFACE LOW IS
OVER THE NORTHERN END OF LAKE MI WITH ITS COLD FRONT EXTENDING
THROUGH WI AND EASTERN IA. THE LOW WILL CONTINUE NE THROUGH THE
NIGHT.
HAVE MUCH HIGHER CONFIDENCE IN THE CONVECTIVE FORECAST TODAY
COMPARED TO YESTERDAY DUE TO CLEAR FORCING MECHANISMS. EXPECTING TO
HAVE TWO AREAS TO MONITOR. THE FIRST IS NORTHWEST OF I-55 WHERE
ISOLATED TO SCATTERED STORMS WILL CONTINUE TO FESTER THROUGH THIS
AFTERNOON AHEAD OF UPPER LEVEL WAVE AND COLD FRONT.
THE BIGGER CONCERN WILL BE ALONG AND SE OF I-55 WHERE A LINE OF
SHOWERS AND STORMS HAS ALREADY DEVELOPED. THE LATEST RAP ANALYSIS
SHOWS A NICE CORRIDOR OF MOISTURE CONVERGENCE WHERE THE CONVECTION
HAS FIRED. THE LATEST AMDAR SOUNDINGS ARE CAPLESS WITH 1000-1500
J/KG OF CAPE. HOWEVER...LAPSE RATES ARE POOR AND WIND SHEAR IS
MINIMAL AT BEST. THE AMDAR SOUNDINGS DO HAVE LOW LEVEL INVERTED
V/S AND THE RAP ANALYSIS HAS AROUND 1000 J/KG OF DOWNDRAFT CAPE.
THEREFORE NOT EXPECTING WIDESPREAD SEVERE WEATHER...BUT A STORM OR
TWO MAY PULSE UP AND PRODUCE SEVERE WINDS.
HEAVY DOWNPOURS ARE ALSO EXPECTED WITH PWAT VALUES OF 1.6-1.8
INCHES. BASED ON SHORT TERM GUIDANCE...THE AREA MOST CONCERNING IS
SOUTH OF A VALPARAISO IN TO GIBSON CITY IL LINE. STORMS WILL
CONTINUE TO DEVELOP AND MOVE OVER THIS REGION WITH AMPLE FORCING.
THEREFORE IF STORMS TRAIN OVER THE SAME AREA FOR AN EXTENDED PERIOD
OF TIME...FLASH FLOODING MAY OCCUR.
STORMS DIMINISH AND PUSH EAST OVERNIGHT WHILE HIGH PRESSURE SPREADS
OVER THE REGION. WINDS WILL DIMINISH AND FOG IS POSSIBLE.
SUNDAY...
SUNDAY LOOKS DRY WITH HIGH PRESSURE OVER THE REGION. WE WILL BE IN
THE NEXT LOW/S WARM SECTOR WITH 850MB TEMPS AROUND 18C. THEREFORE
RAISED HIGH TEMPS INTO THE MID 80S AWAY FROM THE LAKE. THE WEAK
PRESSURE GRADIENT WILL ALLOW A LAKE BREEZE TO FORM AND KEEP THE IL
LAKEFRONT AROUND 80. GUIDANCE HAS SLOWED THE NEXT LOW SO PUSHED
BACK POPS SUNDAY NIGHT.
JEE
MONDAY...
UPPER WAVE DIGGING TOWARDS THE INTER-MOUNTAIN WEST THIS AFTERNOON
WILL LIFT ACROSS THE PLAINS INTO THE UPPER MIDWEST ON MONDAY WITH
ATTENDANT SURFACE LOW DEEPENING AS IT LIFTS ACROSS ONTARIO TO NEAR
JAMES BAY BY LATE MONDAY. A SURFACE FRONT WILL SLOWLY PUSH ACROSS
THE REGION MONDAY AND GUIDANCE HAS TRENDED TOWARDS A SLOWER SOLUTION
OVER THE LAST 24 HOURS. MODERATE TO STRONG INSTABILITY IS PROGGED TO
DEVELOP ALONG AND AHEAD OF THE FRONT WHERE THE GFS ADVERTISES A
CORRIDOR OF JUST OVER 2000 J/KG MLCAPE JUST TO THE WEST OF THE CWA
MONDAY AFTERNOON. THE BETTER CONVERGENCE ASSOCIATED WITH THE COLD
FRONT MAY ARRIVE JUST PAST THE MOST FAVORABLE DIURNAL TIMING IF
TIMING TRENDS HOLD TRUE...BUT THE RIGHT ENTRANCE REGION TO THE UPPER
JET IS PROGGED TO MOVE OVER THE AREA BY MID TO LATE IN THE EVENING
WITH DEEP LAYER SHEAR VALUES INCREASING TO AROUND 40 KT OR SO WHICH
WOULD BE SUFFICIENT FOR AN ORGANIZED SEVERE WEATHER THREAT...THOUGH
THIS THREAT SHOULD DIMINISH WEST TO EAST AS WE GET LATER INTO THE
OVERNIGHT HOURS AND THE BOUNDARY LAYER STABILIZES.
TUESDAY THROUGH THURSDAY...
A SECONDARY SHORTWAVE TROUGH IS PROGGED TO PUSH ACROSS THE REGION ON
TUESDAY BRINGING ADDITIONAL CHANCES FOR SHOWER AND THUNDERSTORMS
MAINLY ACROSS SOUTH/SOUTHEASTERN PORTIONS OF THE CWA WHERE THE
FRONTAL BOUNDARY MAY STILL SLOWLY BE MAKING A PUSH. MODERATE TO
STRONG HEIGHTS RISES QUICKLY BUILD IN BEHIND THIS FEATURE THOUGH AND
SHOULD RESULT IN A DRY WEATHER FOR MOST OF THE FORECAST AREA
TUESDAY. THE GFS IS PARTICULAR IS HOLDING ONTO SOME POPS NORTH OF
THE BOUNDARY WEDNESDAY INTO THURSDAY WHERE PERSISTENT WARM ADVECTION
WILL RESULT IN MID LEVEL ASCENT...THOUGH THE ECMWF REMAINS DRY THIS
PERIOD. WILL MAINTAIN SLIGHT CHANCE POPS IN THE MEANTIME.
FRIDAY THROUGH SATURDAY...
THERMAL RIDGE IS EXPECTED TO MOVE BACK OVERHEAD LATE IN THE WEEK
WITH H85 TEMPS PUSHING INTO THE LOW 20C RANGE WHICH WILL LEAD TO
ANOTHER WARM UP WITH TEMPS INTO THE UPPER 80S. ANOTHER SLOW MOVING
COLD FRONT WILL THEN SAG SOUTH ACROSS THE REGION BRINGING RENEWED
CHANCES FOR SHOWERS AND THUNDERSTORMS.
DEUBELBEISS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* SLIGHT CHANCE OF FOG/STRATUS EARLY SUNDAY MORNING.
* CHANCE FOR A LAKE BREEZE/WIND SHIFT TO EASTERLY LATE SUNDAY
AFTERNOON.
KREIN
//DISCUSSION...UPDATED 06Z...
SCT TSRA WILL CONTINUE TONIGHT WELL TO THE SOUTHEAST OF THE
TERMINALS OVER EAST CENTRAL IL AND WEST CENTRAL INDIANA. AN OLD
BOUNDARY LIES JUST SOUTH OF THE TERMINALS WITH SLIGHTLY DRIER/LESS
HUMID AIR TO THE NORTH...MOSTLY NOTABLE IN THE DEWPOINT GRADIENT.
GIVEN THE LACK OF RAIN TODAY AND MIXING OUT OF LOW LEVEL
MOISTURE...PLUS THE URBAN HEAT ISLAND EFFECTS...NOT ANTICIPATING
FOG/STRATUS TO BE MUCH OF AN ISSUE FOR THE CHICAGO TERMINALS.
HOWEVER...SHORT RANGE MODEL GUIDANCE IS STILL INDICATING A HIGH
POSSIBILITY OF IFR CIGS/VSBY AWAY FROM THE HIGHLY URBANIZED
AREAS...SO WILL MAINTAIN MVFR/IFR FOG AT THE MORE FOG PRONE
OUTLYING TERMINALS...PARTICULARLY GYY/DPA/RFD. ANY VSBY
RESTRICTIONS THAT DO FORM OVERNIGHT WILL QUICKLY DISSIPATE BY MID
MORNING SUNDAY WITH VFR CONDITIONS EXPECTED THE REMAINDER OF THE
DAY. WINDS SHOULD REMAIN LIGHT ENOUGH TO ALLOW A LAKE BREEZE TO
DEVELOP...BUT THERE APPEARS TO BE LITTLE PUSH BEHIND THE
BOUNDARY...SO AT THIS POINT...FEEL THAT CHANCES ARE LOW THAT THE
LAKE BREEZE WILL PUSH INLAND OF ORD/MDW. HOWEVER...IF THE LAKE
BREEZE DOES MANAGE TO PUSH WEST OF ORD/MDW...IT WOULD NOT BE UNTIL
ARND 22-23Z AND ELY WINDS WOULD BE ARND 5-7KT.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM-HIGH CONFIDENCE IN NO IFR AT ORD/MDW OVERNIGHT.
* MEDIUM TO HIGH CONFIDENCE IN LAKE BREEZE SUNDAY AFTERNOON...AND
MEDIUM CONFIDENCE THAT THE BOUNDARY WILL NOT PUSH THROUGH
ORD/MDW.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...
MONDAY...PERIOD OR TWO OF SHRA/TSRA...STRONG TSRA POSSIBLE.
TUESDAY AND WEDNESDAY...PREDOMINANTLY VFR.
THURSDAY...SLIGHT CHANCE TSRA...OTHERWISE VFR.
FRIDAY...CHANCE TSRA.
IZZI
&&
.MARINE...
300 AM CDT
A PERIOD OF CHANGEABLE WEATHER...IN PARTICULAR...WIND
DIRECTION...IS SETTING UP FOR THE NEXT SEVERAL DAYS. LOW PRESSURE
JUST NORTH OF GEORGIAN BAY WILL TRACK EAST TO SOUTHERN QUEBEC BY
LATE SUNDAY MORNING WHILE DRAGGING A WEAK COLD FRONT SOUTH ACROSS
THE LAKE AND CLEARING THE SOUTH END OF LAKE MICHIGAN BY EARLY
SUNDAY. THIS WILL SET UP A BRIEF PERIOD OF NWLY WINDS...BUT AS
HIGH PRESSURE BUILDS OVER THE NORTHERN LAKES BEHIND THE FRONT
SUNDAY AFTERNOON WINDS WILL BECOME LGT/VRBL FOR A SHORT TIME.
SLY FLOW WILL RETURN TO THE LAKE SUNDAY NIGHT AND
MONDAY...STRENGTHENING TO ARND 25KT AS ANOTHER LOW DEVELOPING OVER
THE NORTHERN PLAINS DEEPENS WHILE TRACKING TO HUDSON BAY MONDAY
NIGHT. THIS LOW WILL DRAG ANOTHER COLD FRONT SOUTH ACROSS LAKE
MICHIGAN MONDAY NIGHT. WEAK HIGH PRESSURE WILL BUILD ACROSS THE
LAKE TUESDAY BRINGING ANOTHER PERIOD OF LIGHT WINDS. BUT YET
ANOTHER LOW IS EXPECTED TO MOVE OUT OF THE NORTHERN ROCKIES AND
INTO THE NORTHERN PLAINS WEDNESDAY NIGHT...BRINGING ANOTHER PERIOD
OF BRISK SOUTH WINDS TO THE LAKE FOR WEDNESDAY AND THURSDAY. THIS
LOW IS FORECAST TO TRACK TO NEAR THE SOUTHERN TIP OF JAMES BAY
DRAGGING ANOTHER COLD FRONT ACROSS THE LAKE FRIDAY OR FRIDAY
NIGHT. ACCOMPANYING THESE FRONTAL PASSAGES WILL ALSO BE PERIODS OF
THUNDERSTORMS AS WELL.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
102 AM CDT SUN AUG 31 2014
.DISCUSSION...
221 PM CDT
SYNOPSIS...SCATTERED THUNDERSTORMS ARE POSSIBLE NW OF I-55 WHILE A
LINE OF STORMS WILL IMPACT AREAS ALONG AND EAST OF I-55 THROUGH THIS
EVENING. TOMORROW WILL BE DRY BUT UNSETTLED WEATHER RETURNS MONDAY
WITH MULTIPLE CHANCES FOR THUNDERSTORMS. SEVERE STORMS ARE POSSIBLE
MONDAY. TEMPERATURES WILL BE ABOVE NORMAL THROUGH THE PERIOD WITH A
COUPLE DAYS GETTING INTO THE MID 80S.
THROUGH TONIGHT...
AN UPPER LEVEL TROUGH IS OVER THE UPPER MISSISSIPPI RIVER VALLEY AND
IT WILL PASS OVER THE REGION THROUGH THIS EVENING. A SURFACE LOW IS
OVER THE NORTHERN END OF LAKE MI WITH ITS COLD FRONT EXTENDING
THROUGH WI AND EASTERN IA. THE LOW WILL CONTINUE NE THROUGH THE
NIGHT.
HAVE MUCH HIGHER CONFIDENCE IN THE CONVECTIVE FORECAST TODAY
COMPARED TO YESTERDAY DUE TO CLEAR FORCING MECHANISMS. EXPECTING TO
HAVE TWO AREAS TO MONITOR. THE FIRST IS NORTHWEST OF I-55 WHERE
ISOLATED TO SCATTERED STORMS WILL CONTINUE TO FESTER THROUGH THIS
AFTERNOON AHEAD OF UPPER LEVEL WAVE AND COLD FRONT.
THE BIGGER CONCERN WILL BE ALONG AND SE OF I-55 WHERE A LINE OF
SHOWERS AND STORMS HAS ALREADY DEVELOPED. THE LATEST RAP ANALYSIS
SHOWS A NICE CORRIDOR OF MOISTURE CONVERGENCE WHERE THE CONVECTION
HAS FIRED. THE LATEST AMDAR SOUNDINGS ARE CAPLESS WITH 1000-1500
J/KG OF CAPE. HOWEVER...LAPSE RATES ARE POOR AND WIND SHEAR IS
MINIMAL AT BEST. THE AMDAR SOUNDINGS DO HAVE LOW LEVEL INVERTED
V/S AND THE RAP ANALYSIS HAS AROUND 1000 J/KG OF DOWNDRAFT CAPE.
THEREFORE NOT EXPECTING WIDESPREAD SEVERE WEATHER...BUT A STORM OR
TWO MAY PULSE UP AND PRODUCE SEVERE WINDS.
HEAVY DOWNPOURS ARE ALSO EXPECTED WITH PWAT VALUES OF 1.6-1.8
INCHES. BASED ON SHORT TERM GUIDANCE...THE AREA MOST CONCERNING IS
SOUTH OF A VALPARAISO IN TO GIBSON CITY IL LINE. STORMS WILL
CONTINUE TO DEVELOP AND MOVE OVER THIS REGION WITH AMPLE FORCING.
THEREFORE IF STORMS TRAIN OVER THE SAME AREA FOR AN EXTENDED PERIOD
OF TIME...FLASH FLOODING MAY OCCUR.
STORMS DIMINISH AND PUSH EAST OVERNIGHT WHILE HIGH PRESSURE SPREADS
OVER THE REGION. WINDS WILL DIMINISH AND FOG IS POSSIBLE.
SUNDAY...
SUNDAY LOOKS DRY WITH HIGH PRESSURE OVER THE REGION. WE WILL BE IN
THE NEXT LOW/S WARM SECTOR WITH 850MB TEMPS AROUND 18C. THEREFORE
RAISED HIGH TEMPS INTO THE MID 80S AWAY FROM THE LAKE. THE WEAK
PRESSURE GRADIENT WILL ALLOW A LAKE BREEZE TO FORM AND KEEP THE IL
LAKEFRONT AROUND 80. GUIDANCE HAS SLOWED THE NEXT LOW SO PUSHED
BACK POPS SUNDAY NIGHT.
JEE
MONDAY...
UPPER WAVE DIGGING TOWARDS THE INTER-MOUNTAIN WEST THIS AFTERNOON
WILL LIFT ACROSS THE PLAINS INTO THE UPPER MIDWEST ON MONDAY WITH
ATTENDANT SURFACE LOW DEEPENING AS IT LIFTS ACROSS ONTARIO TO NEAR
JAMES BAY BY LATE MONDAY. A SURFACE FRONT WILL SLOWLY PUSH ACROSS
THE REGION MONDAY AND GUIDANCE HAS TRENDED TOWARDS A SLOWER SOLUTION
OVER THE LAST 24 HOURS. MODERATE TO STRONG INSTABILITY IS PROGGED TO
DEVELOP ALONG AND AHEAD OF THE FRONT WHERE THE GFS ADVERTISES A
CORRIDOR OF JUST OVER 2000 J/KG MLCAPE JUST TO THE WEST OF THE CWA
MONDAY AFTERNOON. THE BETTER CONVERGENCE ASSOCIATED WITH THE COLD
FRONT MAY ARRIVE JUST PAST THE MOST FAVORABLE DIURNAL TIMING IF
TIMING TRENDS HOLD TRUE...BUT THE RIGHT ENTRANCE REGION TO THE UPPER
JET IS PROGGED TO MOVE OVER THE AREA BY MID TO LATE IN THE EVENING
WITH DEEP LAYER SHEAR VALUES INCREASING TO AROUND 40 KT OR SO WHICH
WOULD BE SUFFICIENT FOR AN ORGANIZED SEVERE WEATHER THREAT...THOUGH
THIS THREAT SHOULD DIMINISH WEST TO EAST AS WE GET LATER INTO THE
OVERNIGHT HOURS AND THE BOUNDARY LAYER STABILIZES.
TUESDAY THROUGH THURSDAY...
A SECONDARY SHORTWAVE TROUGH IS PROGGED TO PUSH ACROSS THE REGION ON
TUESDAY BRINGING ADDITIONAL CHANCES FOR SHOWER AND THUNDERSTORMS
MAINLY ACROSS SOUTH/SOUTHEASTERN PORTIONS OF THE CWA WHERE THE
FRONTAL BOUNDARY MAY STILL SLOWLY BE MAKING A PUSH. MODERATE TO
STRONG HEIGHTS RISES QUICKLY BUILD IN BEHIND THIS FEATURE THOUGH AND
SHOULD RESULT IN A DRY WEATHER FOR MOST OF THE FORECAST AREA
TUESDAY. THE GFS IS PARTICULAR IS HOLDING ONTO SOME POPS NORTH OF
THE BOUNDARY WEDNESDAY INTO THURSDAY WHERE PERSISTENT WARM ADVECTION
WILL RESULT IN MID LEVEL ASCENT...THOUGH THE ECMWF REMAINS DRY THIS
PERIOD. WILL MAINTAIN SLIGHT CHANCE POPS IN THE MEANTIME.
FRIDAY THROUGH SATURDAY...
THERMAL RIDGE IS EXPECTED TO MOVE BACK OVERHEAD LATE IN THE WEEK
WITH H85 TEMPS PUSHING INTO THE LOW 20C RANGE WHICH WILL LEAD TO
ANOTHER WARM UP WITH TEMPS INTO THE UPPER 80S. ANOTHER SLOW MOVING
COLD FRONT WILL THEN SAG SOUTH ACROSS THE REGION BRINGING RENEWED
CHANCES FOR SHOWERS AND THUNDERSTORMS.
DEUBELBEISS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* SLIGHT CHANCE OF FOG/STRATUS EARLY SUNDAY MORNING.
* CHANCE FOR A LAKE BREEZE/WIND SHIFT TO EASTERLY LATE SUNDAY
AFTERNOON.
KREIN
//DISCUSSION...UPDATED 06Z...
SCT TSRA WILL CONTINUE TONIGHT WELL TO THE SOUTHEAST OF THE
TERMINALS OVER EAST CENTRAL IL AND WEST CENTRAL INDIANA. AN OLD
BOUNDARY LIES JUST SOUTH OF THE TERMINALS WITH SLIGHTLY DRIER/LESS
HUMID AIR TO THE NORTH...MOSTLY NOTABLE IN THE DEWPOINT GRADIENT.
GIVEN THE LACK OF RAIN TODAY AND MIXING OUT OF LOW LEVEL
MOISTURE...PLUS THE URBAN HEAT ISLAND EFFECTS...NOT ANTICIPATING
FOG/STRATUS TO BE MUCH OF AN ISSUE FOR THE CHICAGO TERMINALS.
HOWEVER...SHORT RANGE MODEL GUIDANCE IS STILL INDICATING A HIGH
POSSIBILITY OF IFR CIGS/VSBY AWAY FROM THE HIGHLY URBANIZED
AREAS...SO WILL MAINTAIN MVFR/IFR FOG AT THE MORE FOG PRONE
OUTLYING TERMINALS...PARTICULARLY GYY/DPA/RFD. ANY VSBY
RESTRICTIONS THAT DO FORM OVERNIGHT WILL QUICKLY DISSIPATE BY MID
MORNING SUNDAY WITH VFR CONDITIONS EXPECTED THE REMAINDER OF THE
DAY. WINDS SHOULD REMAIN LIGHT ENOUGH TO ALLOW A LAKE BREEZE TO
DEVELOP...BUT THERE APPEARS TO BE LITTLE PUSH BEHIND THE
BOUNDARY...SO AT THIS POINT...FEEL THAT CHANCES ARE LOW THAT THE
LAKE BREEZE WILL PUSH INLAND OF ORD/MDW. HOWEVER...IF THE LAKE
BREEZE DOES MANAGE TO PUSH WEST OF ORD/MDW...IT WOULD NOT BE UNTIL
ARND 22-23Z AND ELY WINDS WOULD BE ARND 5-7KT.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM-HIGH CONFIDENCE IN NO IFR AT ORD/MDW OVERNIGHT.
* MEDIUM TO HIGH CONFIDENCE IN LAKE BREEZE SUNDAY AFTERNOON...AND
MEDIUM CONFIDENCE THAT THE BOUNDARY WILL NOT PUSH THROUGH
ORD/MDW.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...
MONDAY...PERIOD OR TWO OF SHRA/TSRA...STRONG TSRA POSSIBLE.
TUESDAY AND WEDNESDAY...PREDOMINANTLY VFR.
THURSDAY...SLIGHT CHANCE TSRA...OTHERWISE VFR.
FRIDAY...CHANCE TSRA.
IZZI
&&
.MARINE...
221 PM CDT
MODERATE SOUTHWEST FLOW IS CURRENTLY IN PLACE ACROSS LAKE MICHIGAN
WHERE SOUTHWEST WINDS ARE GUSTING 20 TO 25 KTS WITH OCCASIONAL 30 KT
WINDS. A SMALL CRAFT ADVISORY HAS BEEN ISSUED FOR THE NEARSHORE
WATERS THROUGH LATE THIS EVENING. THIS IS AHEAD OF LOW PRESSURE
CURRENTLY CENTERED NEAR GREEN BAY. THE LOW WILL DRAG A COLD FRONT
SOUTH ACROSS LAKE MICHIGAN TONIGHT TURNING WINDS TO THE NORTHWEST.
WINDS WILL ABATE BRIEFLY AS TRANSIENT HIGH PRESSURE PUSHES ACROSS
THE NORTHERN LAKES REGION...BUT BY MIDDAY SUNDAY WINDS ARE EXPECTED
TO BEGIN TO TURN SOUTHEAST AND START TO RAMP UP AGAIN AHEAD OF
ANOTHER AREA OF LOW PRESSURE. THIS NEXT WILL LOW LIFT FROM THE
NORTHERN PLAINS...DEEPENING AS IT HEADS TO HUDSON BAY MONDAY NIGHT
INTO TUESDAY. SOUTH WINDS ARE EXPECTED TO PEAK MONDAY OVER THE LAKE
WITH GUSTS SOLIDLY INTO THE 20 KT RANGE...APPROACHING 30 KT OVER THE
NORTH END OF THE LAKE. ANOTHER COLD FRONT WILL SAG SOUTH ACROSS LAKE
MICHIGAN MONDAY NIGHT.
DEUBELBEISS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1251 AM EDT SUN AUG 31 2014
.SYNOPSIS...
ISSUED AT 1250 AM EDT SUN AUG 31 2014
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL REMAIN POSSIBLE
THIS MORNING ALONG A WEAK FRONTAL BOUNDARY. DRIER AIR WILL FILTER
INTO THE AREA LATER TODAY INTO TONIGHT AS HIGH PRESSURE BRIEFLY
BUILDS INTO THE GREAT LAKES REGION. A COLD FRONT WILL PUSH IN FROM
THE WEST MONDAY INTO MONDAY EVENING BRINGING RENEWED CHANCES FOR
SHOWERS AND THUNDERSTORMS. HIGHS WILL REACH INTO THE UPPER 70S TO
LOWS 80 TODAY AND THE LOW TO MID 80S ON MONDAY.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 335 PM EDT SAT AUG 30 2014
CONVECTIVE DEVELOPMENT HAS TRIGGERED WHERE THE CLOUDS CLEARED
EARLIER TODAY...MAINLY OVER CENTRAL ILLINOIS TO LOWER LAKE
MICHIGAN AND INTO NORTHERN MICHIGAN. BEST SYNOPTIC SCALE FORCING
ASSOCIATED WITH THE LOW/TROF IN WISCONSIN. FLOW REGIME IS SUCH
THAT THE CONVECTION HAS DEVELOPED IN A STRETCHING DEFORMATION
AXIS. HRRR AND LOCAL WRF SHOW THE SFC BASED FRONTOGENESIS IN THIS
AXIS...
LAPSE RATES AND WIND PROFILES SUPPORT THE POTENTIAL FOR CONVECTIVE
LINES AND INDIVIDUAL LINE SEGMENTS. ISOLATED THREAT FOR SEVERE WIND
GUSTS. DO NOT EXPECT TO SEE SUSTAINED CONVECTIVE DEVELOPMENT AS THE
BOUNDARY LAYER FORCING DOES NOT PERSIST MUCH PAST 04Z.
LOW LEVEL JET KICKS IN OVERNIGHT AND THIS SHOULD BE ENOUGH TO
SUSTAIN MORE ORGANIZED SHRA/TSRA ACROSS THE SOUTHEASTERN HALF OF THE
FORECAST AREA. WHILE THERE IS DISCREPANCY IN TIMING AND INTENSITY
BETWEEN THE MODELS...THE BOUNDARY LAYER CAPE AND WIND PROFILES ARE
VERY SIMILAR AND DO SUPPORT PERSISTENT/LINGERING SHOWERS THROUGH
SUNDAY MORNING. WITH ABUNDANT MOISTURE TAP AND A LONG FETCH OF
ISENTROPIC ASSENT...SOME OF THE SHOWERS COULD PRODUCE MODERATE TO
LOCALLY HEAVY RAINFALL.
AS THE LOW LEVEL JET DECREASES AND THE TROF/DEFORMATION AXIS SHIFTS
EASTWARD...EXPECT IMPROVING CONDITIONS DURING THE DAY SUNDAY AHEAD
OF ANOTHER MORE ROBUST SYNOPTIC SYSTEM APPROACHING THE AREA FOR
MONDAY.
&&
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 335 PM EDT SAT AUG 30 2014
MAIN FOCUS OF LONG TERM IS ON PRECIP/SEVERE WEATHER CHANCES MONDAY
INTO MONDAY NIGHT. WELL DEFINED MID/UPPER LEVEL TROUGH CURRENTLY
DIGGING INTO THE PACIFIC NORTHWEST WILL SWING THROUGH THE GREAT
LAKES LATE MONDAY. TROUGH WILL BE LIFTING AS IT MOVES THROUGH THE
REGION BUT STRONG PUSH OF HEIGHT FALLS AND CVA WILL SUPPORT A DECENT
SURFACE CYCLONE AND ATTENDANT COLD FRONT. PRECIP CHANCES WILL BE
FURTHER AIDED BY GOOD RIGHT ENTRANCE JET DYNAMICS OVER THE SOUTHERN
GREAT LAKES. DEEP AND STRONG SOUTHWEST FLOW AHEAD OF THE TROUGH WILL
EASILY ADVECT HIGH THETA-E AIRMASS BACK INTO OUR AREA ON MONDAY.
AFTERNOON SBCAPE VALUES EXPECTED TO REACH THE 2-3 KJ/KG RANGE AS
HIGH TEMPS CLIMB INTO THE MID...OR PERHAPS UPPER...80S WITH SURFACE
DEWPOINTS IN THE LOW 70S. VERY DYNAMIC WAVE WILL LIKELY SUPPORT
NUMEROUS SHOWERS AND THUNDERSTORMS BUT TIMING WILL BE CRITICAL TO
SEVERE WEATHER CHANCES. LATEST 12Z NWP SUITE KEEPS SURFACE BOUNDARY
WEST OF OUR CWA UNTIL TUESDAY MORNING. ISO/SCT CONVECTION MAY
DEVELOP IN THE WARM SECTOR MONDAY AFTERNOON ALONG WEAK PREFRONTAL
TROUGH AS SUGGESTED BY THE LATEST NAM12 BUT EXPECT BULK OF THE
ACTIVITY WILL BE TIED TO THE ACTUAL COLD FRONT LATE MONDAY NIGHT.
BETTER WIND PROFILES...WITH 0-6KM SHEAR OF 30+ KNOTS...WILL ALSO BE
TIED CLOSER TO THE FRONT. DESPITE MORE THAN ADEQUATE
SHEAR...MIDLEVEL LAPSE RATES OF 6-7 C/KM ARE ONLY WEAKLY SUPPORTIVE
OF A NOCTURNAL SEVERE WEATHER THREAT. FORECAST SOUNDINGS INDICATE
ONLY AROUND 1000 J/KG OF ELEVATED INSTABILITY MONDAY NIGHT....PLENTY
FOR WIDESPREAD THUNDERSTORMS BUT SEVERE POTENTIAL IS LESS CLEAR.
THERE WILL BE A THREAT FOR SEVERE WINDS...AND POTENTIAL
ROTATION...WITH ANY SUBSTANTIVE UPDRAFTS THAT MANAGE TO DEVELOP BUT
LATE ARRIVAL OF FRONT MAY LIMIT CHANCES FOR A WIDESPREAD SEVERE
WEATHER EVENT. PUSHED BACK TIMING OF POPS BUT ALSO INCREASED THEM A
BIT BASED ON LATEST MODEL SOLUTIONS. COULD ALSO BE A THREAT FOR
STRONGER STORMS IN OUR FAR SOUTHEAST COUNTIES LATE TUESDAY MORNING
IF SURFACE BOUNDARY IS SLOW ENOUGH TO EXIT THE CWA.
QUIET WEATHER EXPECTED MIDWEEK BEFORE ANOTHER TROUGH APPROACHES NEXT
WEEKEND. SCT CONVECTION MAY BE POSSIBLE THURSDAY INTO FRIDAY AS WARM
FRONT LIFTS NORTH ONCE AGAIN BUT BEST CHANCES LOOK TO HOLD OFF UNTIL
THE WEEKEND. AFTER A BRIEF BREAK TUES AND WED...HEAT AND HUMIDITY
WILL RETURN FOR THE END OF THE WEEK AS ACTIVE WEATHER PATTERN
CONTINUES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1250 AM EDT SUN AUG 31 2014
HIGH BOUNDARY LAYER MOISTURE AND WEAK CONVERGENCE INVOF OF A SFC
TROUGH WILL ALLOW CIGS TO LOWER INTO MAINLY IFR-LOW MVFR THIS
MORNING. BROKEN/POORLY ORGANIZED CONVECTIVE LINE ALONG THIS SFC
TROUGH WILL SAG SLOWLY SSE INTO THE KFWA AREA THIS MORNING/EARLY
AFTERNOON. OPTED FOR A VCSH MENTION FOR NOW GIVEN UNCERTAINTY/WEAK
FORCING. PCPN SHOULD REMAIN SOUTH/EAST OF KSBN WITH POTENTIAL FOR
FOG/LIFR CONDITIONS TO FILL IN TOWARD DAYBREAK. CONDITIONS SHOULD
GRADUALLY IMPROVE TO VFR THIS AFTERNOON.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...STEINWEDEL
SHORT TERM...LEWIS
LONG TERM...AGD
AVIATION...STEINWEDEL
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AREA FORECAST DISCUSSION
NWS DODGE CITY KS
417 AM CDT SUN AUG 31 2014
...UPDATED LONG TERM SECTION...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 333 AM CDT SUN AUG 31 2014
THE HRRR WAS INDICATING A BROKEN LINE OF RELATIVELY LIGHT
REFLECTIVITY MOVING EASTWARD FROM THE AFOREMENTIONED DEVELOPMENT
ZONE INTO CENTRAL KS BY AROUND 10-12 UTC. THIS SOLUTION WAS FOLLOWED
WITH BASICALLY LOW POPS BELOW 20 PERCENT. THE MORE SIGNIFICANT ISSUE
FOR THE DAY WILL BE A LATE DAY OR EVENING SEVERE WEATHER THREAT. THE
NMM AND ARW MODEL RUNS DEVELOPED A QLCS TYPE BOWING SEGMENT ACROSS
NORTHERN KS, ALONG AND AHEAD OF A COLD FRONT/DRYLINE INTERSECTION
OVER NORTHERN KS. FARTHER SOUTH, OVER OUR AREA, ANY CONVECTION IN
THESE SOLUTIONS COULD BE GENERALLY MORE DISCREET AND MORE HIGH BASED
(HAIL AND WIND THREATS POSSIBLE) WITH SUFFICIENT SHEAR FOR
SUPERCELLS. HOWEVER, IT IS POSSIBLE OUTFLOWS/COLD POOLS COULD FORCE
MORE WIDESPREAD DEVELOPMENT FARTHER BRINGING MORE OF OUR AREA
INTO A SEVERE WEATHER THREAT.
SURFACE WINDS WILL BE MORE BREEZY AHEAD OF THE DRYLINE THIS
AFTERNOON. MODELS SUGGEST 15 TO 20 KNOTS SUSTAINED WINDS WILL BE
COMMON WITH GUSTS IN TO JUST UNDER 30 KNOTS. YESTERDAY`S HIGHS OF
LOW 90S TO MID 90S IN THE SOUTHWEST SECTIONS ARE A REASONABLE TELL
FOR HIGHS TODAY. THE LATEST SHORT TERM CONSENSUS SUPPORTS MID 90S
TO NEAR 100 DEGREES IN THE SW GIVEN THE COMBINATION OF SLIGHTLY
DRIER AIR AND BETTER DOWNSLOPE. WITH THE FRONTAL BOUNDARY AND
POTENTIAL MOIST BOUNDARY LAYER OUTFLOW ACROSS THE AREA TONIGHT, A
LARGE GRADIENT OF AROUND 20 DEGREES COULD EXIST FOR OVERNIGHT LOWS
FROM MID 50`S OUT WEST TO MID 70S IN THE PRATT COLDWATER AND
MEDICINE LODGE AREA SETTING AN EARLY MILD LOW JUST AFTER
MIDNIGHT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 414 AM CDT SUN AUG 31 2014
THE FRONT FOLLOWING TONIGHTS STORM SYSTEM WILL REACH THE TEXAS
PANHANDLE AND ADJACENT WESTERN OKLAHOMA BY LATE MONDAY/MONDAY NIGHT.
THE DAYTIME HOURS MONDAY WILL BE FAIRLY TRANQUIL AS SUBSIDENCE WILL
PREVAIL IN THE WAKE OF THE DEPARTING SYSTEM. MODEST TEMPERATURES IN
THE 80S ARE EXPECTED. THE FRONT WILL STALL OUT MONDAY NIGHT AND WE
WILL FIND OURSELVES IN THE RIGHT ENTRANCE REGION OF AN UPPER
TROPOSPHERIC JET. THIS WILL ENHANCE FRONTOGENESIS IN THE 900-800MB
LAYER, SUPPORTING NOCTURNAL THUNDERSTORMS ONCE THE LOW LEVEL JET
DEVELOPS. THE MOST FAVORABLE LOCATION FOR MONDAY NIGHT/EARLY TUESDAY
STORMS WILL BE ACROSS SOUTH CENTRAL KANSAS, WHICH IS WHERE WE WILL
HAVE THE HIGHEST CHANCE POPS (AROUND 40 PERCENT). THIS FRONTAL ZONE
WILL NOT MOVE TUESDAY, AND WE WILL NEED TO CARRY SOME CHANCE POPS
THROUGH THE DAY ACROSS SOUTH CENTRAL KANSAS. DAYTIME TEMPERATURES
WILL BE AT OR JUST SLIGHTLY ABOVE AVERAGE FOR THE FIRST PART OF
SEPTEMBER (MID TO UPPER 80S AS A RULE). THE FRONT WILL EVENTUALLY
DISSOLVE BY LATE TUESDAY NIGHT AND ESPECIALLY BY WEDNESDAY, AS THE
LOW LEVEL FLOW FIELD BEGINS TO RESPOND TO LOWER PRESSURE MUCH
FARTHER NORTH WHERE THE POLAR JET WILL BE LOCATED. THE NEXT STORM
SYSTEM MID-WEEK WILL BE MUCH FARTHER NORTH WITH WEAK ZONAL FLOW
ACROSS COLORADO AND KANSAS FOR THE MOST PART. THIS WILL LEAD TO
WARMER TEMPERATURES AND DRIER WEATHER. WEDNESDAY AND THURSDAY
CONTINUE TO LOOK LIKE THE HOTTEST DAYS NEXT WEEK WITH AFTERNOON
HIGHS IN THE 95-100F RANGE FOR MUCH OF WESTERN AND SOUTHERN KANSAS.
THE NORTHERN POLAR JET STORM SYSTEM THAT WAS MENTIONED WILL MOVE
EAST ACROSS THE NORTHERN GREAT PLAINS/ADJACENT CANADIAN PRAIRIES
LATE IN THE WEEK, USHERING IN SOME MUCH COOLER TEMPERATURES ACROSS
THE NORTHERN PLAINS. THIS AIRMASS WILL LIKELY REACH KANSAS BY END OF
WEEK AND INTO THE WEEKEND. THERE APPEARS TO BE A FAIRLY STRONG
SIGNAL OF COOLER/WETTER WEATHER SEPTEMBER 6-8 TIME FRAME.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1122 PM CDT SAT AUG 30 2014
A VERY SMALL CLUSTER OF GRADUALLY WEAKENING THUNDERSTORMS NEAR
GARDEN CITY EARLIER WERE MOVING TO THE SOUTH OF THE DDC TERMINAL AND
EXPECTED TO NOT HAVE A DIRECT IMPACT. HOWEVER, ELEVATED WARM
ADVECTION SHOWERS AND PROBABLY ISOLATED THUNDERSTORMS MAY MOVE
THROUGH THE AREA BETWEEN 6 AND 10 Z. ANY THUNDERSTORMS SHOULD BE TOO
FEW AND FAR BETWEEN TO CONSIDER FOR EVEN A TEMPO GROUP AT THIS TIME.
SLIGHTLY MORE BREEZY CONDITIONS ARE EXPECTED SUNDAY AFTERNOON AHEAD
OF A SURFACE DRYLINE. THESE MORE BREEZY CONDITIONS ARE EXPECTED FROM
DDC TO HYS. LATE AFTERNOON TO EVENING DEEP MOIST CONVECTION MAY
DEVELOP ANYWHERE ALONG THE DRYLINE OR AND INCOMING COLD FRONT
NORTH OF GARDEN CITY IN THE EVENING, POSSIBLY POSING A LOW
PROBABILITY SEVERE THREAT WITH THE BEST CHANCES NEAR THE HYS
TERMINAL.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 98 65 87 65 / 30 50 10 30
GCK 99 62 87 63 / 40 50 10 20
EHA 100 62 91 63 / 10 10 10 10
LBL 102 65 91 64 / 20 20 10 20
HYS 96 64 84 63 / 50 80 20 20
P28 99 71 90 70 / 10 20 20 50
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...RUSSELL
LONG TERM...UMSCHEID
AVIATION...33
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
337 AM CDT SUN AUG 31 2014
...UPDATED SHORT TERM...
.SYNOPSIS...
ISSUED AT 333 AM CDT SUN AUG 31 2014
WIDELY SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WERE DEVELOPING
FROM THE NORTHEAST TEXAS PANHANDLE THROUGH LIBERAL AND NORTHWARD TO
NEAR THE I-70 CORRIDOR WEST OF CEDAR BLUFF. THESE WERE ASSOCIATED
WITH A WARM AIR AND MOISTURE ADVECTION PATTERN ACROSS THE WESTERN
1/3 OF KS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 333 AM CDT SUN AUG 31 2014
THE HRRR WAS INDICATING A BROKEN LINE OF RELATIVELY LIGHT
REFLECTIVITY MOVING EASTWARD FROM THE AFOREMENTIONED DEVELOPMENT
ZONE INTO CENTRAL KS BY AROUND 10-12 UTC. THIS SOLUTION WAS FOLLOWED
WITH BASICALLY LOW POPS BELOW 20 PERCENT. THE MORE SIGNIFICANT ISSUE
FOR THE DAY WILL BE A LATE DAY OR EVENING SEVERE WEATHER THREAT. THE
NMM AND ARW MODEL RUNS DEVELOPED A QLCS TYPE BOWING SEGMENT ACROSS
NORTHERN KS, ALONG AND AHEAD OF A COLD FRONT/DRYLINE INTERSECTION
OVER NORTHERN KS. FARTHER SOUTH, OVER OUR AREA, ANY CONVECTION IN
THESE SOLUTIONS COULD BE GENERALLY MORE DISCREET AND MORE HIGH BASED
(HAIL AND WIND THREATS POSSIBLE) WITH SUFFICIENT SHEAR FOR
SUPERCELLS. HOWEVER, IT IS POSSIBLE OUTFLOWS/COLD POOLS COULD FORCE
MORE WIDESPREAD DEVELOPMETN FARTHER BRINGING MORE OF OUR AREA INTO A
SEVERE WEATHER THREAT.
SURFACE WINDS WILL BE MORE BREEZY AHEAD OF THE DRYLINE THIS
AFTERNOON. MODELS SUGGEST 15 TO 20 KNOTS SUSTAINED WINDS WILL BE
COMMON WITH GUSTS IN TO JUST UNDER 30 KNOTS. YESTERDAY`S HIGHS OF
LOW 90S TO MID 90S IN THE SOUTHWEST SECTIONS ARE A REASONABLE TELL
FOR HIGHS TODAY. THE LATEST SHORT TERM CONSENSUS SUPPORTS MID 90S
TO NEAR 100 DEGREES IN THE SW GIVEN THE COMBINATION OF SLIGHTLY
DRIER AIR AND BETTER DOWNSLOPE. WITH THE FRONTAL BOUNDARY AND
POTENTIAL MOIST BOUNDARY LAYER OUTFLOW ACROSS THE AREA TONIGHT, A
LARGE GRADIENT OF AROUND 20 DEGREES COULD EXIST FOR OVERNIGHT LOWS
FROM MID 50`S OUT WEST TO MID 70S IN THE PRATT COLDWATER AND
MEDICINE LODGE AREA SETTING AN EARLY MILD LOW JUST AFTER
MIDNIGHT.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 243 PM CDT SAT AUG 30 2014
A SURFACE BOUNDARY WILL EXTEND FROM NORTHEAST COLORADO INTO
NORTH CENTRAL KANSAS AT 00Z SUNDAY AS AN UPPER LEVEL TROUGH
BEGINS TO MOVE OUT INTO THE CENTRAL HIGH PLAINS. GIVEN THE
EXPECTED LOW LEVEL MOISTURE POOLING NORTH OF THIS FRONT ALONG WITH
LOCATION OF THE LEFT EXIT REGION OF AN UPPER LEVEL JET AND LATE
DAY INSTABILITY NEAR THE NORTHERN EDGE OF A +13C TO +16C 700MB
TEMPERATURE GRADIENT WILL CONTINUE TO FAVOR CONVECTION INCREASING
IN AREAL COVERAGE DURING THE EARLY EVENING AS IT SPREADS EAST
ACROSS NORTHWEST AND NORTH CENTRAL KANSAS. SEVERE THUNDERSTORMS
WILL BE POSSIBLE SUNDAY EVENING IN THIS AREA BASED ON THE 0-6KM
SHEAR VALUES RANGING FROM 30 TO 40 KNOTS WITH SURFACE BASED CAPES
GREATER THAN 2000 J/KG. WIDESPREAD HEAVY RAINFALL MAY ALSO BE AN
ISSUE ACROSS NORTH CENTRAL KANSAS OVERNIGHT GIVEN THE PRECIPTABLE
WATER VALUES OF 1.5 TO NEAR 2 INCHES AND A LOW LEVEL JET DEVELOPS
AHEAD OF THE EASTWARD MOVING UPPER LEVEL TROUGH. AT THIS TIME
MODELS DIFFERING SOME ON WHERE THE MID LEVEL BAROCLINIC ZONE WILL
BE SUNDAY NIGHT AND DUE TO LOW CONFIDENCE ON WHERE IT WILL BE
SUNDAY NIGHT HAVE DECIDED TO STAY CLOSE TO THE PREVIOUS FORECAST
ON SOUTHERN EXTENT OF THE OVERNIGHT CONVECTION. THIS WILL KEEP THE
BULK OF PRECIPITATION SUNDAY NIGHT ALONG AND NORTH OF HIGHWAY 96.
FURTHER SOUTH A DRYLINE WILL BE LOCATED ACROSS WESTERN KANSAS,
HOWEVER ABOVE THIS DRYLINE 700MB TEMPERATURES WERE FORECAST TO
WARM TO +14 TO NEAR +16C. THESE WARM MID LEVEL TEMPERATURES WILL
LIMIT HOW WIDESPREAD CONVECTION WILL BE FURTHER SOUTH, HOWEVER AT
THIS TIME AM NOT COMPLETELY ABLE TO RULE ON A FEW SCATTERED/WIDELY
SCATTERED THUNDERSTORMS EARLY SUNDAY NIGHT. WITH SIMILAR
INSTABILITY AND SHEAR VALUES EXPECTED IN THE EVENING ANY STORM
WHICH DOES DEVELOP ALONG THE DRYLINE WILL ALSO HAVE THE POTENTIAL
FOR BECOMING SEVERE.
AS THE UPPER LEVEL TROUGH MOVES INTO CENTRAL NEBRASKA AND NORTH
CENTRAL KANSAS A COLD FRONT WILL MOVE SOUTH ACROSS WESTERN KANSAS
LATE SUNDAY NIGHT. RAIN WILL END FROM WEST TO EAST AND LOWER
DEWPOINTS/COOLER AIR WILL BEGIN TO BRIEFLY SETTLE INTO SOUTHWEST
KANSAS BY EARLY MONDAY. GUSTY NORTH WINDS JUST BEHIND THE FRONT
WILL DECREASE DURING THE DAY AS AN AREA OF HIGH PRESSURE EXITS
MOVES ACROSS NORTHWEST KANSAS. 850MB TEMPERATURES AT 00Z TUESDAY
SUPPORTING HIGHS MAINLY IN THE 80S. HIGHS IN THE LOWER 90S STILL
APPEAR POSSIBLE NEAR THE OKLAHOMA BORDER.
MOISTURE, WARM AIR ADVECTION, AND ISENTROPIC LIFT IMPROVES MONDAY
NIGHT INTO TUESDAY ACROSS SOUTHWEST AND SOUTH CENTRAL KANSAS AS
ANOTHER UPPER LEVEL DISTURBANCE CROSSES THE CENTRAL PLAINS. THIS
WILL RESULT IN INCREASING CLOUDS AND POSSIBLY A FEW
SHOWERS/THUNDERSTORMS NORTH OF OUR SURFACE BOUNDARY. INCREASING
CLOUDS MONDAY NIGHT WILL AID IN KEEPING TEMPERATURES UP WHILE AT
THIS TIME IT APPEARS THE BETTER CHANCES FOR PRECIPITATION WILL BE
ACROSS SOUTH CENTRAL KANSAS.
A WARMING TREND WILL THEN DEVELOP MID WEEK AS A WARM FRONT LIFTS
NORTH ACROSS KANSAS AND A WESTERLY DOWNSLOPE FLOW IMPROVES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1122 PM CDT SAT AUG 30 2014
A VERY SMALL CLUSTER OF GRADUALLY WEAKENING THUNDERSTORMS NEAR
GARDEN CITY EARLIER WERE MOVING TO THE SOUTH OF THE DDC TERMINAL AND
EXPECTED TO NOT HAVE A DIRECT IMPACT. HOWEVER, ELEVATED WARM
ADVECTION SHOWERS AND PROBABLY ISOLATED THUNDERSTORMS MAY MOVE
THROUGH THE AREA BETWEEN 6 AND 10 Z. ANY THUNDERSTORMS SHOULD BE TOO
FEW AND FAR BETWEEN TO CONSIDER FOR EVEN A TEMPO GROUP AT THIS TIME.
SLIGHTLY MORE BREEZY CONDITIONS ARE EXPECTED SUNDAY AFTERNOON AHEAD
OF A SURFACE DRYLINE. THESE MORE BREEZY CONDITIONS ARE EXPECTED FROM
DDC TO HYS. LATE AFTERNOON TO EVENING DEEP MOIST CONVECTION MAY
DEVELOP ANYWHERE ALONG THE DRYLINE OR AND INCOMING COLD FRONT
NORTH OF GARDEN CITY IN THE EVENING, POSSIBLY POSING A LOW
PROBABILITY SEVERE THREAT WITH THE BEST CHANCES NEAR THE HYS
TERMINAL.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 98 65 87 65 / 30 50 10 30
GCK 99 62 87 63 / 40 50 10 20
EHA 100 62 91 63 / 10 10 10 10
LBL 102 65 91 64 / 20 20 10 20
HYS 96 64 84 63 / 50 80 20 20
P28 99 71 90 70 / 10 20 20 30
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RUSSELL
SHORT TERM...RUSSELL
LONG TERM...BURGERT
AVIATION...33
AREA FORECAST DISCUSSION
NWS GOODLAND KS
237 AM MDT SUN AUG 31 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 237 AM MDT SUN AUG 31 2014
SHORTWAVE THAT BROUGHT SCATTERED RW/TRW TO PORTIONS OF THE FORECAST
AREA OVERNIGHT WILL CONTINUE TO SHIFT EAST OF THE AREA THIS
MORNING...WITH SOME LINGERING MID CLOUD COVER STILL TO CLR THE
REGION BY MID MORNING. EXPECTING CONDITIONS TO IMPROVE BY MIDDAY
AS WEAK RIDGING PROVIDE SEVERAL HOURS OF DRY CONDITIONS BEFORE
NEXT ROUND OF PRECIPITATION MOVES TO AFFECT THE AREA LATER THIS
AFTERNOON INTO THE EVENING HOURS.
IT IS THIS TIMEFRAME THAT WILL POSE A SEVERE WX THREAT TO MUCH OF
THE TRI STATE REGION. HIGH PRESSURE IS GOING TO GIVE WAY TO A STRONG
SHORTWAVE TROUGH AND ASSOCIATED COLD FRONT LATER THIS AFTERNOON AND
SWING THRU THE AREA THRU 12Z MONDAY. LATEST MODEL TRACK OF THE UPPER
TROUGH THRU THE PERIOD...PUTS BEST DYNAMICS FOR SEVERE CONDITIONS
OVER EASTERN ZONES...ESPECIALLY AREAS NORTH AND EAST OF GOODLAND.
BULK SHEAR 0-6KM WILL RANGING FROM 37 KTS SOUTH TO NEAR 60 KTS
NORTH...COMBINED WITH LL JET 30-40KTS...LI/S -4 TO -8 AND HIGH
DEWPTS WILL ALLOW FOR POTENTIAL SEVERE THUNDER TO DEVELOP...EVEN THE
CHANCE FOR A TORNADO. THIS IS REINFORCED BY SPC PUTTING MUCH OF THE
FORECAST AREA IN SLIGHT RISK IN THE AFOREMENTIONED TIMEFRAME WHERE
DAMAGING WINDS AND LARGE HAIL/TORNADO ARE POSSIBLE. HAVE THUS
CONTINUED ENHANCED WORDING IN FORECAST FOR THESE ELEMENTS. MODELS DO
KEEP SYSTEM FAIRLY PROGRESSIVE THRU THE AREA OVERNIGHT WITH PRECIP
TAPERING FROM WEST TO EAST BY 06Z-12Z.
HIGHS TODAY WILL RANGE FROM THE MID 80S THRU THE MID 90S...WHILE THE
COLD FRONT WILL HELP TO DROP THE AREA INTO THE MID 50S TO LOW 60S
FOR LOWS TONIGHT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 237 AM MDT SUN AUG 31 2014
GOING INTO MONDAY...FRONTAL BOUNDARY AND ASSOCIATED PRECIPITATION
HAS SHIFTED WELL EAST OF THE FORECAST AREA...ALLOWING FOR HIGH
PRESSURE TO BUILD OVER THE REGION. BY MONDAY EVENING RIGHT INTO
TUESDAY MORNING...MODELS SHOW FRONTAL BOUNDARY STALLING OVER THE
GREAT LKS REGION BACK DOWN ACROSS SOUTHERN PORTIONS OF KANSAS BUT
CLRING OUT BY MIDDAY TUESDAY FOR A QUIET STRETCH OF WEATHER INTO
TUESDAY NIGHT DUE TO SFC HIGH PRESSURE. WITH RIDGE BLOCKING MOST OF
THE CWA FROM THE STALLED FRONT...WILL ONLY PUT IN 15-25 POPS ALONG
EXTREME SOUTHERN ZONES FOR TRW/RW. TEMPERATURES DURING THIS TIME
FRAME WILL RANGE IN THE MID 80S FOR HIGHS...DOWN TO THE MID 50S TO
LOW 60S FOR OVERNGT LOWS.
THE EXTENDED PERIOD WILL START OUT DRY WITH TEMPERATURES WARMER THAN
PREVIOUS DAYS. BROAD UPPER RIDGING WILL CONTINUE ACROSS A LARGE
PORTION OF THE SOUTHERN AND CENTRAL UNITED STATES THROUGH MID WEEK
WITH A PROGRESSIVE ZONAL FLOW PATTERN IN THE HIGHER LATITUDES. LATE
IN THE PERIOD...IN RESPONSE TO A MID/UPPER SHORTWAVE THAT WILL CROSS
THE NORTHERN PLAINS...THE LEE SURFACE TROUGH WILL EVOLVE INTO A
BROAD ELONGATING LOW WITH INCREASING BAROCLINICITY IN THE TRAILING
PORTION THAT MOVES THROUGH OUR AREA. ALONG AND BEHIND THIS
FRONT...SHOWERS AND THUNDERSTORM CHANCES WILL BEGIN THURSDAY NIGHT
AND LAST THROUGH SATURDAY. TEMPERATURES WILL GRADUALLY FALL LATE IN
THE WEEK LIKELY REACHING BELOW NORMAL LEVELS BY THE WEEKEND.
ALTHOUGH SOME DISAGREEMENT EXISTS...CONSENSUS OF DETERMINISTIC
GUIDANCE SEEMS TO FALL IN ABOUT THE MIDDLE OF ENSEMBLE MEMBERS SO
CONFIDENCE IS ABOUT AVERAGE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1137 PM MDT SAT AUG 30 2014
PERSISTENT VFR CONDITIONS EXPECTED THROUGH THIS TAF CYCLE.
SHOWERS/ISOLATED STORMS ARE MOVING INTO KGLD SO HAVE PLACED VCTS
BACK INTO TAF. KGLD VAD WIND PROFILE DEPICTS A LOW LEVEL JET OF 45
KTS OVER KGLD AT PRESENT TIME WITH RAP MODEL ANALYSIS INDICATING
STRONG WINDS OVER KMCK. MAINTAINED LLWS IN TAF WITH OUTFLOW
BOUNDARIES AND SOMEWHAT ERRATIC SURFACE WINDS MOVING THROUGH. FOR
THIS AFTERNOON...PLACED VCTS INTO KMCK TAF AS CONVECTION IS
EXPECTED TO DEVELOP AHEAD OF A VIGOROUS UPPER LEVEL DISTURBANCE.
STORMS COULD PRODUCE STRONG WIND GUSTS IN EXCESS OF 50 KTS AND
LARGE HAIL. NOT CONFIDENT ENOUGH TO PLACE TS INTO KGLD TAF AS
MOST MODEL GUIDANCE REMAINS INSISTENT CONVECTION STAYS NORTHEAST.
COLD FRONT SLIDES THROUGH DURING THE EVENING...BRINGING LIGHT
NORTH WINDS AND CALM WEATHER BEHIND THE UPPER LEVEL DISTURBANCE.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...JN
LONG TERM...JN/BRB
AVIATION...RRH
AREA FORECAST DISCUSSION
NWS GOODLAND KS
121 AM MDT SUN AUG 31 2014
.UPDATE...
ISSUED AT 119 AM MDT SUN AUG 31 2014
UPDATE ISSUED TO INCREASE POPS FOR TRW/RW THAT HAS DEVELOPED...AND
WILL CARRY THRU UNTIL NEXT ESTF AND/OR 12Z THIS MORNING. BULK OF
ANY REMAINING PRECIP WILL BE FOCUSED OVER AREAS EAST OF GOODLAND.
REST OF FORECAST ON TRACK AT THIS TIME.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 1239 PM MDT SAT AUG 30 2014
18Z WATER VAPOR IMAGERY INDICATED SHORT WAVE RIDGING IN PLACE
ACROSS THE NORTHERN PLAINS WITH NOTICEABLE SHORT WAVE TROUGH
MOVING INTO UTAH. AT THE SURFACE...LEE TROUGH DEVELOPING ACROSS
WESTERN CWA WITH SOUTHWESTERLY WINDS IN THE 10 TO 20 KT RANGE
COMMON.
PRIMARY FORECAST CONCERN WILL CENTER AROUND PRECIP CHANCES THIS
EVENING AND AGAIN ON SUNDAY.
TONIGHT...SHORT WAVE TROUGH CURRENTLY OVER UTAH WILL CONTINUE TO
DRIFT TO THE EAST TONIGHT...WITH LARGE SCALE FORCING INCREASING
BETWEEN 03 AND 09Z IN RESPONSE. INSTABILITY...BOTH SURFACE AND
ELEVATED APPEAR TO BE VERY LIMITED SO DO NOT ANTICIPATE MANY
STRONG/SEVERE STORMS. WHILE A FEW LATE AFTERNOON STORMS ARE
POSSIBLE...DO EXPECT BEST CHANCES TO OCCUR WHEN LARGE SCALE
FORCING/INCREASING LLJ ARE MAXIMIZED.
TOMORROW...POTENTIAL FOR SEVERE THUNDERSTORMS...ESPECIALLY IN THE
EASTERN CWA LOOKS ON TRACK AS FRONTAL BOUNDARY SLOWLY SAGS SOUTH
ACROSS THE AREA. THINK BEST CHANCE FOR CONVECTIVE INITIATION WILL
BE ALONG DEVELOPING DRY LINE TO THE THE SOUTH OF THE FRONTAL ZONE.
WHILE STRONG INSTABILITY AND SHEAR EXIST TO THE NORTH OF
FRONT...STRONG CAP MAKES ANY EARLY INITIATION UNLIKELY. A FEW
STORMS COULD DEVELOP OVER THE HIGHER TERRAIN AND DRIFT INTO THE
CWA...BUT THIS SCENARIO MOST LIKELY AFTER SUNSET.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 230 PM MDT SAT AUG 30 2014
MAIN FOCUS IS STILL ON THE POTENTIAL FOR SEVERE THUNDERSTORMS INTO
SUNDAY EVENING AS SURFACE COLD FRONT MOVES ACROSS THE FORECAST
AREA AND THE AXIS OF THE UPPER TROUGH SWEEPS ACROSS THE CENTRAL
HIGH PLAINS REGION. WITH HIGHS IN THE 90S AND DEWPOINTS IN THE
UPPER 50S TO LOWER 60S...INSTABILITY AND SHEAR SHOULD BE
FAVORABLE FOR SUPERCELLS ACROSS THE EASTERN PORTION OF THE
FORECAST AREA WITH LARGE HAIL AND ISOLATED TORNADOS TRANSITIONING
INTO MAINLY A WIND THREAT BY LATE EVENING.
COOLER...NEAR AVERAGE...TEMPERATURES FOR THIS TIME OF YEAR ARE
EXPECTED ON MONDAY BEHIND THE COLD FRONT AS THE REGION DRIES OUT
WITH HIGH PRESSURE MOVING IN AT THE SURFACE AND THE UPPER FLOW
BECOMING ZONAL THROUGH THE MIDDLE OF THE WEEK. WARMER TEMPERATURES
ARE EXPECTED THROUGH THE LATTER HALF OF THE WEEK AS THE LARGE AREA
OF HIGH PRESSURE ALOFT EXPANDS ACROSS THE SOUTHERN UNITED STATES.
THE UPPER FLOW TURNS MORE SOUTHWESTERLY AND A LEE TROUGH DEEPENS
ALONG THE EASTERN COLORADO BORDER THROUGH THE LATTER HALF OF NEXT
WEEK...BRINGING ANOTHER PERIOD OF ISOLATED TO SCATTERED
THUNDERSTORMS ACROSS THE CENTRAL HIGH PLAINS EACH DAY AS
DISTURBANCES MOVE OUT OF THE SOUTHWEST UNITED STATES...EAST OF THE
ROCKIES...AND ACROSS THE PLAINS STATES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1137 PM MDT SAT AUG 30 2014
PERSISTENT VFR CONDITIONS EXPECTED THROUGH THIS TAF CYCLE.
SHOWERS/ISOLATED STORMS ARE MOVING INTO KGLD SO HAVE PLACED VCTS
BACK INTO TAF. KGLD VAD WIND PROFILE DEPICTS A LOW LEVEL JET OF 45
KTS OVER KGLD AT PRESENT TIME WITH RAP MODEL ANALYSIS INDICATING
STRONG WINDS OVER KMCK. MAINTAINED LLWS IN TAF WITH OUTFLOW
BOUNDARIES AND SOMEWHAT ERRATIC SURFACE WINDS MOVING THROUGH. FOR
THIS AFTERNOON...PLACED VCTS INTO KMCK TAF AS CONVECTION IS
EXPECTED TO DEVELOP AHEAD OF A VIGOROUS UPPER LEVEL DISTURBANCE.
STORMS COULD PRODUCE STRONG WIND GUSTS IN EXCESS OF 50 KTS AND
LARGE HAIL. NOT CONFIDENT ENOUGH TO PLACE TS INTO KGLD TAF AS
MOST MODEL GUIDANCE REMAINS INSISTENT CONVECTION STAYS NORTHEAST.
COLD FRONT SLIDES THROUGH DURING THE EVENING...BRINGING LIGHT
NORTH WINDS AND CALM WEATHER BEHIND THE UPPER LEVEL DISTURBANCE.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JN
SHORT TERM...JRM
LONG TERM...LOCKHART
AVIATION...RRH
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1137 PM MDT SAT AUG 30 2014
.UPDATE...
ISSUED AT 854 PM MDT SAT AUG 30 2014
UPDATED THE FORECAST TO MAKE ADJUSTMENTS FOR THIS EVENING/TONIGHT
AND INCLUDE LATEST GUIDANCE INTO SEVERE WEATHER CHANCES TOMORROW
AFTERNOON/EVENING.
FOR TONIGHT...LOWERED POPS AND MENTIONED ISOLATED THUNDER.
ACTIVITY IS NOT IMPRESSIVE COMING IN FROM COLORADO AND CAP HAS
LIMITED CONVECTION OVER THE TRI-STATE REGION.
FORECAST STILL LOOKS GOOD FOR TOMORROW. BEST CHANCES FOR SEVERE
WEATHER LIES ALONG AND WEST OF HIGHWAY 83. THERE COULD BE A CHANCE
OF A TORNADO OR TWO NORTH AND EAST OF A LINE FROM TRENTON
NEBRASKA TO HOXIE AND HILL CITY KANSAS. LCLS OF 1300-1600
METERS...FAVORABLE SHEAR AND TURNING OF WINDS IN BOUNDARY LAYER
WILL PROVIDE AN ENVIRONMENT CONDUCIVE TO TORNADO DEVELOPMENT. MAIN
THREATS ARE BE LARGE HAIL AND DAMAGING WINDS BUT COULD NOT RULE
OUT A TORNADO OR TWO.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 1239 PM MDT SAT AUG 30 2014
18Z WATER VAPOR IMAGERY INDICATED SHORT WAVE RIDGING IN PLACE
ACROSS THE NORTHERN PLAINS WITH NOTICEABLE SHORT WAVE TROUGH
MOVING INTO UTAH. AT THE SURFACE...LEE TROUGH DEVELOPING ACROSS
WESTERN CWA WITH SOUTHWESTERLY WINDS IN THE 10 TO 20 KT RANGE
COMMON.
PRIMARY FORECAST CONCERN WILL CENTER AROUND PRECIP CHANCES THIS
EVENING AND AGAIN ON SUNDAY.
TONIGHT...SHORT WAVE TROUGH CURRENTLY OVER UTAH WILL CONTINUE TO
DRIFT TO THE EAST TONIGHT...WITH LARGE SCALE FORCING INCREASING
BETWEEN 03 AND 09Z IN RESPONSE. INSTABILITY...BOTH SURFACE AND
ELEVATED APPEAR TO BE VERY LIMITED SO DO NOT ANTICIPATE MANY
STRONG/SEVERE STORMS. WHILE A FEW LATE AFTERNOON STORMS ARE
POSSIBLE...DO EXPECT BEST CHANCES TO OCCUR WHEN LARGE SCALE
FORCING/INCREASING LLJ ARE MAXIMIZED.
TOMORROW...POTENTIAL FOR SEVERE THUNDERSTORMS...ESPECIALLY IN THE
EASTERN CWA LOOKS ON TRACK AS FRONTAL BOUNDARY SLOWLY SAGS SOUTH
ACROSS THE AREA. THINK BEST CHANCE FOR CONVECTIVE INITIATION WILL
BE ALONG DEVELOPING DRY LINE TO THE THE SOUTH OF THE FRONTAL ZONE.
WHILE STRONG INSTABILITY AND SHEAR EXIST TO THE NORTH OF
FRONT...STRONG CAP MAKES ANY EARLY INITIATION UNLIKELY. A FEW
STORMS COULD DEVELOP OVER THE HIGHER TERRAIN AND DRIFT INTO THE
CWA...BUT THIS SCENARIO MOST LIKELY AFTER SUNSET.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 230 PM MDT SAT AUG 30 2014
MAIN FOCUS IS STILL ON THE POTENTIAL FOR SEVERE THUNDERSTORMS INTO
SUNDAY EVENING AS SURFACE COLD FRONT MOVES ACROSS THE FORECAST
AREA AND THE AXIS OF THE UPPER TROUGH SWEEPS ACROSS THE CENTRAL
HIGH PLAINS REGION. WITH HIGHS IN THE 90S AND DEWPOINTS IN THE
UPPER 50S TO LOWER 60S...INSTABILITY AND SHEAR SHOULD BE
FAVORABLE FOR SUPERCELLS ACROSS THE EASTERN PORTION OF THE
FORECAST AREA WITH LARGE HAIL AND ISOLATED TORNADOS TRANSITIONING
INTO MAINLY A WIND THREAT BY LATE EVENING.
COOLER...NEAR AVERAGE...TEMPERATURES FOR THIS TIME OF YEAR ARE
EXPECTED ON MONDAY BEHIND THE COLD FRONT AS THE REGION DRIES OUT
WITH HIGH PRESSURE MOVING IN AT THE SURFACE AND THE UPPER FLOW
BECOMING ZONAL THROUGH THE MIDDLE OF THE WEEK. WARMER TEMPERATURES
ARE EXPECTED THROUGH THE LATTER HALF OF THE WEEK AS THE LARGE AREA
OF HIGH PRESSURE ALOFT EXPANDS ACROSS THE SOUTHERN UNITED STATES.
THE UPPER FLOW TURNS MORE SOUTHWESTERLY AND A LEE TROUGH DEEPENS
ALONG THE EASTERN COLORADO BORDER THROUGH THE LATTER HALF OF NEXT
WEEK...BRINGING ANOTHER PERIOD OF ISOLATED TO SCATTERED
THUNDERSTORMS ACROSS THE CENTRAL HIGH PLAINS EACH DAY AS
DISTURBANCES MOVE OUT OF THE SOUTHWEST UNITED STATES...EAST OF THE
ROCKIES...AND ACROSS THE PLAINS STATES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1137 PM MDT SAT AUG 30 2014
PERSISTENT VFR CONDITIONS EXPECTED THROUGH THIS TAF CYCLE.
SHOWERS/ISOLATED STORMS ARE MOVING INTO KGLD SO HAVE PLACED VCTS
BACK INTO TAF. KGLD VAD WIND PROFILE DEPICTS A LOW LEVEL JET OF 45
KTS OVER KGLD AT PRESENT TIME WITH RAP MODEL ANALYSIS INDICATING
STRONG WINDS OVER KMCK. MAINTAINED LLWS IN TAF WITH OUTFLOW
BOUNDARIES AND SOMEWHAT ERRATIC SURFACE WINDS MOVING THROUGH. FOR
THIS AFTERNOON...PLACED VCTS INTO KMCK TAF AS CONVECTION IS
EXPECTED TO DEVELOP AHEAD OF A VIGOROUS UPPER LEVEL DISTURBANCE.
STORMS COULD PRODUCE STRONG WIND GUSTS IN EXCESS OF 50 KTS AND
LARGE HAIL. NOT CONFIDENT ENOUGH TO PLACE TS INTO KGLD TAF AS
MOST MODEL GUIDANCE REMAINS INSISTENT CONVECTION STAYS NORTHEAST.
COLD FRONT SLIDES THROUGH DURING THE EVENING...BRINGING LIGHT
NORTH WINDS AND CALM WEATHER BEHIND THE UPPER LEVEL DISTURBANCE.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...RRH
SHORT TERM...JRM
LONG TERM...LOCKHART
AVIATION...RRH
AREA FORECAST DISCUSSION
NWS JACKSON KY
342 AM EDT SUN AUG 31 2014
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 335 AM EDT SUN AUG 31 2014
EARLY THIS MORNING...THE REGION REMAINED IN A VERY MOIST AIRMASS
WITH PW OF 2 INCHES OR MORE EXTENDING INTO THE OHIO VALLEY REGION
BETWEEN A RIDGE OF HIGH PRESSURE CENTERED OFF THE SOUTHEAST US COAST
AND A SHORTWAVE TROUGH EXTENDING SOUTH FROM THE GREAT LAKES INTO THE
MS VALLEY REGION. A LULL IN THE SHOWER AND THUNDERSTORM ACTIVITY IS
WORKING NORTH AND NORTHEAST ACROSS THE CWA ATTM AS THE FIRST WAVE IS
BEGINNING TO DEPART. HOWEVER...THE NEXT WAVE IS WORKING INTO THE MID
MS AND LOWER OH VALLEY REGION AS THE DEEP MOISTURE PLUME REMAINS.
OVER THE NEXT COUPLE OF DAYS...THE INITIAL WAVE WILL DEPART TO THE
NORTH AND NORTHEAST...BUT THE NEXT MOST EVIDENT AT THE 850 MB AND 700
MB LEVEL IS EXPECTED TO TRACK EAST NORTHEAST ACROSS THE OH VALLEY
REGION TODAY. THIS SYSTEM SHOULD ONCE AGAIN INTERACT WITH THE DEEP
MOISTURE PLUME IN PLACE ACROSS THE REGION AND LEAD TO RENEWED
CONVECTIVE ACTIVITY TO OUR WEST GRADUALLY TRANSITIONING INTO EASTERN KY
LATER TONIGHT AND INTO THE DAY ON SUNDAY. THIS SYSTEM WILL DEPART TO
THE NORTH AND EAST TONIGHT. THE SOUTHEASTERN RIDGE IS EXPECTED TO
FLATTEN BY TONIGHT AND INTO MONDAY. THE NEXT TROUGH WILL HAVE MOVED
INTO THE UPPER MS VALLEY REGION AND PLAINS FROM THE ROCKIES BY LATE
TONIGHT...WITH THIS TROUGH WORKING INTO THE GREAT LAKES AND
APPROACHING THE LOWER OH VALLEY REGION LATE IN THE PERIOD. THE
ASSOCIATED SFC COLD FRONT IS ALSO EXPECTED TO APPROACH THE LOWER OH
VALLEY REGION LATE IN THE PERIOD...BUT WILL HAVE MORE OF AN EFFECT ON
THE LONG TERM PORTION OF THE FORECAST.
RECENT HRRR RUNS BRING THE STRONGEST ACTIVITY ACROSS THE REGION
DURING THE AFTERNOON INTO THE EARLY EVENING ON SUNDAY. THIS ACTIVITY
SHOULD BE EFFICIENT RAIN PRODUCERS AND WHERE ANY TRAINING OCCURS
LOCALLY HEAVY RAIN AND FLASH FLOODING WILL BE POSSIBLE. A FLASH FLOOD
WATCH IS ALREADY IN PLACE ACROSS WESTERN AND NORTHWESTERN PARTS OF
THE CWA ATTM AND WE PLAN TO KEEP IT IN PLACE WITH NO CHANGES. LATER
SHIFTS MAY WANT TO CONSIDER EXTENDING IT FURTHER SOUTH AND EAST...BUT
RAINFALL OVER THE PAST 24 HOURS HAS BEEN GENERALLY LIGHTER THERE
COMPARED TO THE SOUTHWESTERN PART OF THE CWA WHERE RADAR ESTIMATES
AND RAIN GAGES INDICATE THAT UPWARDS OF 2 INCHES OR MORE HAS FALLEN
ACROSS PARTS OF WAYNE COUNTY AND FROM MCCREARY COUNTY NORTHEAST INTO
LAUREL COUNTY. TEMPERATURES TODAY SHOULD BE SUPPRESSED BELOW
SATURDAYS LEVELS BY THE ANTICIPATED CLOUD COVER AND PRECIPITATION.
LOCALLY HEAVY RAIN WILL BE MENTIONED IN THE HWO OUTSIDE OF LOCATIONS
CURRENTLY IN THE FLASH FLOOD WATCH.
WITH THE WAVE DEPARTING TONIGHT...CHANCES FOR CONVECTION WILL ALSO
DIMINISH. MIN TEMPERATURES WILL REMAIN ON THE MILD SIDE. AT LEAST
PATCHY VALLEY FOG SHOULD DEVELOP...WHERE ANY PARTIAL CLEARING
OCCURS. ON MONDAY...THE REGION WILL MORE OR LESS BE IN BETWEEN
SYSTEMS WITH CONTINUED SOUTHERLY FLOW AND NOT MUCH IN THE WAY OF
FORCING. MAX TEMPERATURES WILL AGAIN BE A FEW DEGREES ABOVE NORMAL
AND COULD APPROACH 90 IN SOME LOCATIONS. THE DAYTIME HEATING OF THE
WARM AND RATHER MOIST AIRMASS IN PLACE BY THE AFTERNOON SHOULD LEAD
TO SOME DIURNALLY DRIVEN CONVECTION FOR MONDAY. AT THIS TIME...ONLY
ISOLATED POPS WERE USED.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 252 AM EDT SUN AUG 31 2014
SUMMER-LIKE WEATHER WILL PERSIST THIS WEEK WITH PLENTY OF WARM AND
HUMID CONDITIONS ON TAP. A STRONG RIDGE WILL CONTINUE TO RESIDE OVER
THE SOUTHEAST THROUGH THE WEEK. BEST CHANCE OF RAIN WILL COME ON
TUESDAY AS A SURFACE TROUGH DROPS INTO EASTERN KENTUCKY BEFORE
STALLING. SOME WEAK FORCING WILL YIELD SCATTERED TO NUMEROUS SHOWERS
AND STORMS THROUGH THE AFTERNOON AND EVENING HOURS. DECENT SHEAR
PROFILES...COMBINED WITH MODEST INSTABILITY COULD YIELD THE
POSSIBILITY OF A FEW STRONG TO SEVERE STORMS ON TUESDAY WITH THE
MAIN THREAT BEING DAMAGING WINDS. OTHERWISE...THE FRONT WILL STALL
OVER THE AREA TUESDAY NIGHT...AND VIRTUALLY WASH OUT. THE
THREAT FOR AFTERNOON/EVENING SHOWERS WILL CONTINUE THROUGH WEEKS END
GIVEN THE DAYTIME INSTABILITY EACH AFTERNOON/EVENING. TEMPERATURES
WILL REMAIN NEAR OR SLIGHT ABOVE NORMAL THROUGH THE WEEK WITH ALL
THE COOLER AIR BOTTLED UP WELL TO OUR NORTH.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 215 AM EDT SUN AUG 31 2014
MVFR OR IFR VIS AND OR CIGS ARE ANTICIPATED AS THE BAND OF CONVECTION
WORKS ACROSS THE EASTERN AND NORTHEASTERN PART OF THE CWA OVER THE
NEXT 2 TO 3 HOURS. VFR HAS DEVELOPED BEHIND THIS BAND OF PRECIPITATION
AND AS THE LULL IN THE ACTIVITY WORKS NORTH ACROSS EAST KY...VFR CIGS
ARE ANTICIPATED UNTIL AT LEAST THE 12Z TO 15Z RANGE. THE PRESS
GRADIENT APPEARS GREAT ENOUGH TO KEEP THE TAF SITES MIXY OVERNIGHT...BUT
SOME MVFR OR LOWER VALLEY FOG MAY STILL DEVELOP BETWEEN 6Z AND 12Z AT
NON TAF SITES. MORE SHOWERS AND SOME THUNDER MAY DEVELOP AGAIN DURING
THE 15Z TO 18Z PERIOD...WITH THIS ACTIVITY DIMINISHING BY THE LAST 6
HOURS OF THE PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH THIS AFTERNOON FOR KYZ044-050>052-
058>060-068-069-079-080-083>086-104-106-108-111-114-116.
&&
$$
SHORT TERM...JP
LONG TERM...KAS
AVIATION...JP
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
516 AM EDT SUN AUG 31 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 514 AM EDT SUN AUG 31 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MID LEVEL RIDGE FROM THE
UPPER MS VALLEY THROUGH WRN LAKE SUPERIOR BTWN A DEPARTING SHRTWV
TROUGH INTO NRN LOWER MI AND AN UPSTREAM SHRTWV OVER THE WRN
DAKOTAS. ISOLATED SHOWERS ASSOCIATED WITH THE COMMA HEAD OF THE MI
SHRTWV WERE EXITING THE ERN CWA. HOWEVER...EXTENSIVE LOW LEVEL
MOISTURE/LOW CLOUDS PERSISTED OVER MUCH OF UPPER MI...EXCEPT FROM
CMX/P59 TO IWD. AT THE SFC...A RIDGE EXTENDED FROM JAMES BAY AND NRN
ONTARIO INTO WRN UPPER MI AND NW WI.
TODAY...AS THE 850-700 MB MOISTURE DEPARTS THIS MORNING AND DAYTIME
HEATING/MIXING INCREASES...EXPECT THAT THE REMAINING CLOUDS OVER THE
CNTRL AND EAST WILL THIN OUT AND GIVE WAY TO SCT CU BY AFTERNOON.
WITH SUBSIDENCE LIMITING INVERSION HEIGHTS CLOSER TO 900 MB...MAX
TEMPS MAINLY IN THE MID 70S ARE IN STORE WITH SOME LOWER READINGS
NEAR THE GREAT LAKES WHERE E OR SSE WINDS PREVAIL.
TONIGHT...AS THE DAKOTAS SHORTWAVE AND ASSOCIATED SFC TROUGH
APPROACH THE REGION SRLY FLOW AND MOISTURE ADVECTION WILL INCREASE.
AS PWAT VALUES CLIMB INTO THE 1.5-2.0 INCH RANGE FROM NW WI TO NEAR
IWD AND LARGE SCALE LIFT INCREASES WITH UPPER LEVEL DIV 700-300 MB
QVECTOR CONV AHEAD OF THE MID LEVEL TROUGH...SHRA/TSRA THAT DEVELOP
OVER MN WILL SPREAD TOWARD AND INTO THE CWA...MAINLY AFT 06Z. WITH
THE INITIAL PUSH OF 850-700 MB THETA-E ADVECTION SOME ISOLD SHRA/TSRA
MAY ALSO SPREAD INTO N CNTRL UPPER MI DURING THE EVENING...BUT
CONFIDENCE INTO CNTRL UPPER MI IS LOW WITH ONLY SLIGHT CHANCE POPS
MENTIONED. THE BEST CHANCE FOR SVR STORMS IS EXPECTED TO REMAIN WEST
OF THE CWA...CLOSER TO THE GREATER INSTABILITY. HOWEVER...WITH
MUCAPE VALUES TO AT LEAST 1K J/KG AND FAVORABLE 0-1KM/0-6KM SHEAR
TO 30/40 KNOTS...SOME STRONG STORMS WILL BE POSSIBLE WITH GUSTY
WINDS AND SMALL HAIL. THE MAIN HAZARD WITH TSRA LATE TONIGHT WILL BE
LOCALLY HEAVY RAIN WITH SOME ISOLD 1-2 INCH AMOUNTS POSSIBLE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 433 AM EDT SUN AUG 31 2014
UPPER LEVELS FEATURE TROUGHING OVER THE CENTRAL CONUS TO BEGIN THE
PERIOD BUT THAT GIVES WAY TO SHALLOW RIDGING BY MID WEEK. SHORTWAVE
TROUGH MOVES FROM ROCKIES TO CENTRAL CANADA BY LATE THIS WEEK...WITH
WARM SW FLOW ALOFT STREAMING ACROSS THE GREAT LAKES. COLD FRONT MOVES
THROUGH AROUND FRIDAY WITH SFC RIDGE AND DRY/COOLER AIR SETTLING
OVER UPPER GREAT LAKES BY NEXT WEEKEND. CHANCES FOR SHRA/TSRA ON
LABOR DAY AS STRONG SHORTWAVE AND COLD FRONT CROSS UPPER GREAT
LAKES. THERE WILL BE ADDITIONAL CHANCES FOR SHRA AND TSRA AHEAD AND
ALONG THE LATE WEEK COLD FRONT AS WELL. EXPECT TEMPS FOR THE MOST
PART TO BE ABOVE NORMAL THROUGH THE WEEK. TEMPS PROBABLY WILL NOT
FALL BLO NORMAL UNTIL NEXT WEEKEND IN WAKE OF THE COLD FRONT PASSAGE
ON FRIDAY.
THUNDER CHANCES AND STRENGTH ON LABOR DAY AND AGAIN WEDNESDAY NIGHT
THROUGH FRIDAY LOOKS TO BE THE HIGHEST IMPACT WEATHER THIS WEEK.
LABOR DAY...INITIAL SHORTWAVE CURRENTLY DRIVING SHRA/TSRA OVER THE
DAKOTAS LIFTS OVER ONTARIO TO START THE DAY WHILE ANOTHER SHORTWAVE
CURRENTLY OVER OREGON/IDAHO TRACKS TOWARD WESTERN GREAT LAKES. MAIN
SFC LOW WILL BE NORTH OF LK SUPERIOR CLOSER TO LEADING SHORTWAVE. SFC
TROUGH WILL EXTEND SOUTH ACROSS UPPER GREAT LAKES REGION AND ON INTO
THE SOUTHERN PLAINS. H85-H5 Q-VECTOR CONVERGENCE MOSTLY IMPACTS CWA
IN THE MORNING. MOISTURE TRANSPORT AT H85-H7 IS MAXIMIZED AHEAD OF
THE FRONT IN THE MORNING AS WELL. THERE WILL BE SOME RISK FOR
STRONGER STORMS AS DURING THIS PERIOD OF FORCING/LIFT THERE IS A H85
JET UP TO 50 KTS FM THE SOUTHWEST/0-6KM SHEAR OVER 40 KTS AND 1-6KM
MUCAPES UP TO 500 J/KG. FREEZING LEVEL IS BTWN 12-13KFT WITH STORM
CORES HAVING TO REACH ABOVE 35 KFT FOR POTENTIAL OF ONE-INCH HAIL.
INSTABILITY WILL BE LIMITING FACTOR...BUT THERE MAY BE AT LEAST
ISOLATED STRONGER STORMS. BY AFTN...MLCAPES SPIKE UP WELL OVER 1000
J/KG ESPECIALLY CNTRL CWA...BUT SFC FRONT IS ON ITS WAY ACROSS CWA BY
THAT TIME AND LARGER SCALE SUBSIDENCE SHOULD BE DEVELOPING IN WAKE OF
SHORTWAVES MOVING THROUGH LATE TONIGHT INTO MONDAY MORNING. IF SFC
FRONT SLOWS UP...EVEN JUST SLIGHTLY...ISOLD STORMS MAY TRY TO DEVELOP
WITH THE INCREASING DAYTIME HEATING/INSTABILITY. RISK OF SEVERE STILL
THERE AS WELL WITH 0-6KM SHEAR 35-40 KTS. MAX TEMPS ON LABOR DAY
HIGHLY DEPEND ON EXTENT OF CLOUD COVER...BUT SEEMS THAT MANY AREAS
WILL SEE READINGS WELL INTO THE 70S. SOUTH WINDS MAY BE GUSTY OVER
EASTERN THIRD OF CWA...ESPECIALLY NEAR LK MICHIGAN SHORE.
FRONT CLEARS EASTERN CWA BY MONDAY EVENING WITH HIGH PRESSURE
SETTLING ACROSS FOR LATER MONDAY NIGHT INTO TUESDAY. ONSHORE WNW
WINDS WILL KEEP LK SUPERIOR SHORE COOLER ON TUESDAY IN THE MID-UPR
60S...BUT TEMPS SHOULD MAINLY BE IN THE LOWER 70S ELSEWHERE.
AS FLOW ALOFT BECOMES MORE ZONAL BY WEDNESDAY MAY START TO SEE
WEAKER SHORTWAVES WORK ACROSS UPR LAKES. GFS/GEM-NH AGGRESSIVE
WITH QPF ON WEDNESDAY BUT GFS SOUNDINGS INDICATE DEEPER MOISTURE IS
LACKING WITH ONLY WEAKER SHORTWAVES SHOWN. PREFER SLOWER ECMWF
SOLUTION SHOWING BETTER CHANCES OF SHRA/TSRA ARRIVING BY WEDNESDAY
NIGHT AS STRONGER SHORTWAVE ARRIVES. LAST FEW RUNS OF ECMWF ARE
SHOWING GREATER SIGNAL OF THIS OCCURRING. STRONG LOW-LEVEL MOISTURE
TRANSPORT AIMED INTO THE UPR LAKES ALONG WITH LARGE AREA OF ML
MUCAPES OVER 1000-1500 J/KG UPSTREAM WITH LIFT ENHANCED BY RIGHT
ENTRANCE REGION OF JET STREAK OVER ONTARIO/QUEBEC COULD RESULT IN AT
LEAST ISOLD STRONG ELEVATED STORMS WEDNESDAY NIGHT INTO THURSDAY
MORNING WITH ANOTHER ROUND OF STRONGER SFC BASED STORMS ALONG FRONTAL
BOUNDARY POSSIBLE LATER THURSDAY. LIMITING FACTOR FOR ADDITIONAL
STORMS LATER IN THE DAY WOULD BE NOT AS MUCH MOISTURE ALONG THE SFC
FRONT IN WAKE OF THE SHORTWAVE THAT MOVES THROUGH THURSDAY MORNING.
TEMPS AHEAD OF THE FRONT ON THURSDAY COULD GET QUITE WARM AS H85
TEMPS SURGE TOWARD +20C. WITH FULL SUNSHINE THIS WOULD SUPPORT HIGHS
INTO THE UPPER 80S IF NOT LOWER 90S. CURRENT FORECAST IS MORE TOWARD
CONSENSUS WITH UNCERTAINTY ON CLOUDS AND PRECIP CHANCES. WILL BE
SOMETHING THAT MAY NEED ADJUSTING IN LATER FORECASTS THOUGH.
THE FRONT...ALONG WITH SOME POTENTIAL FOR ADDITIONAL SHRA/TSRA...
SLIDES EAST AND SOUTH OF MOST CWA BY FRIDAY. HIGH PRESSURE MOVES
ACROSS FOR AT LEAST THE START OF NEXT WEEKEND WITH A MODEST COOLING
TREND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 126 AM EDT SUN AUG 31 2014
EXPECT LINGERING VFR SC CIGS AT IWD AND CMX TO DISSIPATE AS HI PRES
BLDS OVER WRN UPR MI UNDER SUBSIDENCE IN THE WAKE OF DEPARTING UPR
DISTURBANCE. WITH LGT WINDS UNDER THE BLDG HI...EXPECT RADIATION FOG
TO DVLP AND DROP CONDITIONS TO LIFR AND EVEN VLIFR IN THE PRESENCE
OF NOCTURNAL COOLING/LINGERING HI SFC DEWPTS. A MORE STEADY...
UPSLOPE N WIND OFF LK SUP WL MAINTAIN IFR CONDITIONS AT SAW. THE
PRESENCE OF THESE CLDS WL LIMIT THE POTENTIAL FOR THICKER RADIATION
FOG AT SAW. WITH DAYTIME HEATING...EXPECT LINGERING FOG/LO CLDS TO
MIX OUT AND GIVE WAY TO VFR CONDITIONS. THIS PROCESS WL BE SLOWEST
AT SAW AS AN UPSLOPE NE VEERING SE WIND DVLPS ON THE WRN FLANK OF
SFC HI SHIFTING TO THE E. A STRENGTHENING SSW WIND WL OVERSPREAD THE
UPR LKS THIS EVNG BTWN THE DEPARTING SFC HI AND AN APRCHG COLD FNT.
WITH NOCTURNAL COOLING...A LLJ WL DVLP AND MAY BE SUFFICIENTLY
STRONG TO BRING MARGINAL LLWS TO AT LEAST THE WRN IWD/CMX TAF SITES.
RIGHT NOW...IT APPEARS THE INCOMING AIRMASS WL BE TOO DRY TO CAUSE
ANY LO CLDS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 514 AM EDT SUN AUG 31 2014
WINDS WILL BE LESS THAN 20 KTS OR LESS THROUGH MOST OF THE PERIOD
EXCEPT FOR A PERIOD OF SE TO S GUSTS OF 20 TO 30 KNOTS TONIGHT AND
MONDAY MORNING. WINDS WILL THEN VEER WRLY TO 20 KNOTS MON AFTERNOON
AND MON NIGHT IN THE WAKE OF A LOW PRESSURE SYSTEM AND COLD FRONT.
WIDESPREAD FOG WILL CONTINUE THROUGH THIS MORNING AND THEN DEVELOP
AGAIN TONIGHT INTO MONDAY NIGHT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...KC
MARINE...JLB
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
338 AM CDT SUN AUG 31 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 245 AM CDT SUN AUG 31 2014
ALTHOUGH SUNDAY AND ITS POTENTIAL SEVERE WEATHER EVENT ARE
HERE...THE CAMS STILL LEAVE PLENTY OF QUESTIONS AS TO HOW THINGS
WILL EVOLVE LATER TODAY.
FOR THIS MORNING...INITIAL SURGE OF THE LLJ IS MOVING ACROSS THE
DAKOTAS OUT AHEAD OF SHORTWAVE THAT CAN BE SEEN ON WATER VAPOR
MOVING INTO CENTRAL SODAK. ALTHOUGH BEST FORCING AND MOST WIDESPREAD
THUNDERSTORM ACTIVITY CAN BE FOUND AT THE NOSE OF THE LLJ ACROSS
NODAK AND ON ITS WAY TO NW MN...ENOUGH THETA-E ADVECTION AND
ISENTROPIC LIFT IS PRESENT ON THE ERN FLANK OF THE LLJ TO GET SCT
CONVECTION DOWN INTO NE NEB. THE HRRR/HOPWRF/MPXWRF/NMM/ARW ALL SHOW
THIS BAND OF ISO/SCT SHOWERS WORKING ACROSS MN THROUGH THE
MORNING...SO WORKED SOME 20/30 POPS ACROSS MN THIS MORNING TO
ACCOUNT FOR THAT. EXPECT THIS ACTIVITY TO START WEAKENING AS IT
MOVES EAST ACROSS MN AND LIKELY WILL NOT MAKE IT INTO WI AS IT
ENCOUNTERS A PROGRESSIVELY DRIER AIRMASS /SEE 00Z SOUNDING FROM MPX
LAST NIGHT/.
IN THE WAKE OF THIS MORNING ACTIVITY...H85 TEMPS WILL BE INCREASING
TO AROUND 20C. LOOKING AT BUFKIT SOUNDINGS FROM ACROSS THE
AREA...THIS WILL PUT A DECENT CAP IN PLACE THAT LOOKS TO KEEP A LID
ON SURFACE BASED CONVECTION UNTIL ABOUT 00Z. WHERE WE ARE SEEING
SOME VARIABILITY THOUGH WITH THE CAMS IS WITH THE POTENTIAL FOR SOME
ELEVATED CONVECTION TO DEVELOP THIS AFTERNOON OUT AHEAD OF WHAT YOU
COULD CONSIDER THE MAIN SHOW FROM THE SEVERE WEATHER PERSPECTIVE.
THIS ELEVATED CONVECTION LOOKS TO BE TIED TO THE STRONG WAVE ON
WATER VAPOR CURRENTLY MOVING INTO WRN KS. THIS FEATURE HAS A FEW
STORMS ASSOCIATED WITH IT IN KANSAS THIS MORNING AND BY THE
AFTERNOON...THIS WAVE WILL BE NEAR THE MN/IA BORDER. THE CAMS THAT
ARE MOST BULLISH WITH THIS ACTIVITY ARE THE MPXWRF AND ARW...AND
ALTHOUGH IT ENDS AT 21Z...YOU GET A SENSE FROM THE HRRR REFLECTIVITY
FORECAST...IT MAY BE GOING THE SAME WAY IN THE NEXT COUPLE OF RUNS.
THE IMPACT OF THIS ACTIVITY ON THE FORECAST WAS TO SPREAD HIGHER
POPS A BIT FARTHER EAST LATE THIS AFTERNOON THAN THE POSITION OF THE
SFC FEATURES WOULD OTHERWISE SUGGEST.
AS FOR THE POTENTIAL SFC BASED CONVECTION...THE MAIN TREND SEEN WITH
THE CAMS AND 00Z DETERMINISTIC MODELS WAS DELAY ITS START
SOME...WHICH MAKE SENSE GIVEN THE CAPPING SEEN IN THE FORECAST
SOUNDINGS. CURRENT EXPECTATIONS ARE THAT SFC BASED CONVECTION WILL
DEVELOP AROUND 21Z NEAR OMAHA...WHERE INSTABILITY WILL BE
MAXIMIZED...WITH INITIATION ALONG THE FRONT UP IN MN COMING A BIT
CLOSER TO 00Z. GREATEST SEVERE THREAT REALLY LOOKS TO BE DOWN ACROSS
IOWA...WHERE THE COMBINATION OF AN IMPINGING WRLY MID LEVEL JET WITH
A 40-50 KT SWRLY LLJ LOOKS TO MAXIMIZE SHEAR. CAN NOT ARGUE WITH THE
DAY1 SEVERE PROBABILITIES...WHICH HAS THE GREATER SEVERE POTENTIAL
EXISTING FROM I-90 SOUTH. LOOKING AT THE 0-3/0-6 KM SHEAR OF 30-60
KTS WITH VECTORS ORIENTED MOSTLY PERPENDICULAR TO THE FRONT ACROSS
IOWA INDICATES THE POTENTIAL FOR GETTING A STRONG MCS WITH STRONG
WINDS ACROSS IOWA TONIGHT...WHICH IS WHAT THE NMM/ARW CERTAINLY SHOW
EVOLVING. STILL A GOOD DEGREE OF VARIABILITY WITH HOW THIS ACTIVITY
WILL EVOLVE ACROSS THE MPX CWA...WITH SOME SUGGESTION THAT WE MAY
SEE THE GREATEST THUNDERSTORM ACTIVITY SPLIT THE MPX CWA TO THE
NORTH AND SOUTH. CERTAINLY THE HRRR MSLP FORECAST SHOWS SOME MERIT
TO THIS POSSIBILITY...WITH TWO SFC LOWS NOTED BY 21Z. ONE UP IN NRN
MN AND THE OTHER IN WRN KS.
FOR TONIGHT...WE ARE ALSO SEEING THE NMM AND THE ARW TO A LESSER
EXTENT HANGING UP ACTIVITY BACK ACROSS THE CENTER OF THE MPX CWA AS
THEY BOTH DEVELOP A DEFORMATION BAND IN THE WAKE IN THE MAIN COLD
FRONT ACTIVITY. THIS LOOKS TO BE TIED TO THE MAIN SHORT WAVE
POSSIBLY MIXED WITH A BIT OF AN MCV MOVING ACROSS THE UPPER MS
VALLEY LATE TONIGHT. AS A RESULT...HELD ON TO CHANCE POPS A BIT
LONGER BACK ACROSS MOST OF THE MN PORTION OF THE MPX CWA IN THE WAKE
OF THE FRONT. THIS ACTIVITY WOULD NOT HAVE MUCH OF A SEVERE
THREAT...THOUGH IT WOULD SET UP MORE IN A WAY TO ALLOW FOR SOME
TRAINING OF STORMS ALONG A SW TO NE AXIS...SO IT COULD POSE MORE OF
A HYDRO THREAT IF IT MATERIALIZES.
TO SUMMARIZE...WE EXPECT A BAND OF NON-SEVERE SHOWERS/STORMS TO MOVE
ACROSS MN THIS MORNING. STILL A GOOD DEGREE OF UNCERTAINTY WITH
RESPECT THE AFTERNOON ACTIVITY...WITH THE POTENTIAL FOR A PREFRONTAL
TROUGH TO GET ELEVATED CONVECTION GOING BY EARLY AFTERNOON IN THE
EAST...WITH THE GREATEST SEVERE RISK EXISTING FROM ABOUT 6 PM TO
MIDNIGHT FROM SOUTH CENTRAL MN INTO IOWA AHEAD OF THE MAIN SFC COLD
FRONT. EVENTUALLY...A LINE OR TWO OF STORMS LOOKS TO FORM...WITH THE
MAIN SEVERE THREAT BEING DAMAGING STRAIGHT LINE WINDS.
HOWEVER...WHERE ACTIVITY INITIALLY DEVELOPS...IT WILL LIKELY BE
SUPER CELLULAR IN NATURE...WITH LARGE HAIL AND A FEW TORNADOES BEING
POSSIBLE AS WELL...BUT THIS THREAT LOOKS GREATEST FROM ERN NEB INTO
WRN IOWA.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 245 AM CDT SUN AUG 31 2014
THE LONGER TERM WILL INCLUDE SOME ADDITIONAL CHANCES FOR
SHRA/TSRA AS WE SEE THE LARGE SCALE PATTERN ONCE AGAIN BECOME MORE
ZONAL BY THE MIDDLE OF THE WEEK... BEFORE ANOTHER UPPER TROUGH
MOVES INTO THE CENTER OF THE COUNTRY TOWARD THE WEEKEND. THE
MEDIUM RANGE GUIDANCE IS IN FAIRLY GOOD AGREEMENT THROUGH
MIDWEEK... BUT DIVERGES A FAIR AMOUNT BY THE WEEKEND... WHICH
LEADS TO MORE UNCERTAINTY AND NECESSITATES THE INCLUSION OF CHANCE
POPS FOR SEVERAL DAYS.
SOME PCPN WILL LIKELY STILL BE ONGOING ACROSS THE EASTERN PORTION
OF THE AREA ON MONDAY AS THE FRONTAL BOUNDARY SLOWLY PUSHES EAST
INTO THE GREAT LAKES. COULD SEE A FEW SHRA/TSRA SNEAK BACK INTO
THE WESTERN AND CENTRAL PORTION OF THE AREA MONDAY NIGHT INTO
EARLY TUESDAY AS THE UPPER TROUGH/COLD POOL SWING THROUGH THE
REGION. THIS ACTIVITY WILL SHIFT NORTHEAST BY TUESDAY... WITH
RETURN FLOW BEGINNING TO SETUP BY TUESDAY NIGHT. CHANCES FOR
SHRA/TSRA LOOK TO RETURN FROM WEST TO EAST WEDNESDAY INTO THURSDAY
AS A SURFACE LOW SLOWLY TAKES SHAPE OVER THE PLAINS AHEAD OF THE
NEXT UPPER TROUGH... WITH A LONG PERIOD OF MAINLY WEAK ISENTROPIC
LIFT PROGGED ACROSS OUR AREA. THE SPEED WITH WHICH THE SURFACE LOW
MOVES THROUGH OUR AREA VARIES QUITE A BIT AMONGST THE GUIDANCE...
AND AT THIS POINT THERE IS TOO MUCH SPREAD IN THE ENSEMBLE
SOLUTIONS TO HAVE MUCH CONFIDENCE IN ANYTHING SPECIFIC. UNTIL THE
SURFACE LOW AND ASSOCIATED FRONTAL BOUNDARY MOVE THROUGH... WE/LL
CONTINUE TO HAVE A NEED FOR AT LEAST CHANCE POPS. THERE IS ALSO
UNCERTAINTY IN HOW FAR SOUTH THE BOUNDARY WILL BE DISPLACED ONCE
THE SURFACE LOW AND UPPER TROUGH MOVE EAST... WITH THE GUIDANCE
SHOWING VARYING AMPLITUDES OF THE UPPER TROUGH WHICH LEADS TO
DIFFERENCES IN HOW FAR SOUTH THE BOUNDARY IS DISPLACED AS THE
SURFACE HIGH BUILDS INTO THE AREA LATE FRIDAY INTO SATURDAY. AT
THIS POINT... KEPT SOME POPS OVER THE SOUTHERN PART OF THE AREA
INTO SATURDAY TO ACCOUNT FOR THE POSSIBILITY OF THE BOUNDARY
HANGING UP OVER NORTHERN IOWA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1233 AM CDT SUN AUG 31 2014
WITH THE HRRR ALONG WITH VIRTUALLY ALL OTHER CAMS SHOWING A BAND
OF SHRA/TSRA WORKING ACROSS MN WITH INITIAL ARRIVAL OF THE
LLJ...STARTED TO INTRODUCE VCSH IN THE MORNING TO ALL MN
TERMINALS. THIS SCENARIO SEEMS VERY PLAUSIBLE GIVEN THE FACT THAT
WE ARE CURRENTLY SEEING SCT ACTIVITY CLEAR DOWN INTO NC NEB. THE
ATMO HAS ALREADY TIPPED ITS HAND WHEN IT COMES TO FOG AT EAU...SO
HAVE LEFT THEM DOWN THE REST OF THE NIGHT. WITH THAT SAID...THERE
IS STILL A FAIR AMOUNT OF CLOUD COVER IN THE 050-080 LEVEL IN ERN
MN INTO WRN WI...WHICH MAY LEAD TO A BIT OF VARIABILITY IN THE
VSBYS AT RNH/EAU AS THEY SKIP BETWEEN 050-080 CLOUDS AND CLEAR
SKIES /WHICH WILL BE ACCOMPANIED BY FOG/. STILL A GOOD DEGREE OF
VARIABILITY WITH THE 00Z CAMS IN TERMS OF AFTERNOON
CONVECTION...BUT FORECAST SOUNDINGS DO SHOW A GOOD DEGREE OF
CAPPING TO OVERCOME FIRST...SO DID DELAY AFTERNOON TS MENTION AN
HOUR OR TWO FROM WHAT THE 00Z TAF HAD. IN ADDITION...REMOVED THE
AFTERNOON TS MENTION AT AXN...WITH AXN LOOKING TO MOST LIKELY BE
WEST OF THAT ROUND OF STORMS.
KMSP...BEGINNING TO GAIN CONFIDENCE IN AT LEAST SCT SHRA/TSRA IN
THE METRO AREA THIS MORNING...SO HAVE STARTED WITH INTRODUCING A
VCSH GROUP. BY 9Z...SHOULD HAVE A BETTER FEEL FOR WHETHER OR NOT
WE WILL SEE ANYTHING...SO WILL WAIT FOR THAT AMD TO SEE IF WE NEED
ANY STRONGER SHRA/TSRA MENTION. 00Z TAF LOOKED TO HAVE GOOD TIMING
FOR POTENTIAL AFTERNOON TSRA...SO STUCK WITH THAT. IS POTENTIAL
THAT MSP COULD GET SPLIT BY ACTIVITY TODAY...WITH STRONGER
ACTIVITY REMAINING SOUTH OF THE FIELD WITH BETTER LLJ FORCING DOWN
IN IOWA AND GOING NORTH OF THE FIELD...CLOSER TO THE SFC LOW THAT
WILL BE GOING ACROSS NRN MN. STILL...GIVEN THE STRENGTH OF THE
FRONT/FORCING...ODDS LOOK BETTER THAT MSP WILL SEE SOME TSRA
ACTIVITY THAN STORMS MISSING THE AIRPORT.
/OUTLOOK FOR KMSP/
MON...MVFR/TSRA ENDING EARLY. VFR BY AFTERNOON WINDS WNW 5-10 KTS.
TUE...VFR. WINDS WSW 5-10 KTS.
WED...VFR. CHC MVFR/TSRA LATE. WINDS S 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...
AVIATION...MPG
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1252 AM CDT SUN AUG 31 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 242 PM CDT SAT AUG 30 2014
WEAK CONVERGENCE ZONE ALONG WITH MLCAPES AROUND 500 J/KG HAD
GENERATED A FEW SHRA ACROSS SOUTHERN MN TODAY. BOUNDARY LAYER
MOISTURE REMAINS ROBUST...SO CLOUDS HAVE BEEN SLOW TO ERODE DURING
THE TYPICAL DIURNAL AFTERNOON TIME FRAME. AS WINDS REMAIN WEAK AND
CYCLONIC CONTINUES DURING THE LATE AFTERNOON/EARLY EVENING...THESE LOW
CLOUDS MAY HOLD ON UNTIL LATER TONIGHT. ONCE WINDS SHIFT TO THE
SOUTHEAST AHEAD OF A DEEPENING AREA OF LOW PRESSURE ACROSS SD
LATER TONIGHT...ANY LOW CLOUDS SHOULD QUICKLY MOVE OUT OR DISSIPATE.
SOME FOG MAY DEVELOP ACROSS WC WI AS THIS AREA WILL BE LAST TO SEE
BOUNDARY LAYER MOISTURE RETREAT ALONG WITH WEAK MIXING IN THE
BOUNDARY LAYER.
A STRONG JET STREAM MOVING INTO THE PACIFIC NW TODAY WILL SET THE
STAGE FOR A VERY ACTIVE SUNDAY AFTERNOON/EVENING ACROSS THE UPPER
MIDWEST. BOTH AMPLE MOISTURE AND INCREASING SHEAR VALUES...ALONG A
DEEPENING AREA OF LOW PRESSURE ACROSS THE NORTHERN PLAINS...SHOULD
LEAD TO WIDESPREAD THUNDERSTORMS DEVELOPMENT BY THE LATE AFTERNOON
AHEAD OF A COLD FRONT. THERE REMAINS SOME DIFFERENCES IN THE
MODELS IN TERMS OF STRENGTH OF THE LLJ ALONG WITH THE UPPER LEVEL
JET CORE TO CONCLUDE WIDESPREAD SEVERE WX ACROSS THE UPPER
MIDWEST. THE UPPER JET CORE...WHICH IS EXPECTED TO BECOME A JET
COUPLET FROM THE NORTHERN AND SOUTHERN JET STREAMS...SHOULD LEAD
TO STRONG UPPER LEVEL DIFFLUENCE BY SUNDAY EVENING. AGAIN...MODELS
HAVE SOME DIFFERENCES IN THIS JET COUPLET WHICH LEADS TO
DIFFERENCES IN TIMING AND PLACEMENT OF THE HIGHER QPF AMOUNTS. IN
ADDITION...RESIDUAL CLOUD COVER FROM DECAYING MORNING TSRA COULD LIMIT
FULL AFTERNOON ISOLATION. THE BEST AREA FOR BOTH JET STRUCTURE/HIGHER
INSTABILITY AND SHEAR VALUES REMAIN ACROSS IOWA. FAR SC/SW MN
COULD ALSO BE IN THIS AREA OF HIGHER SVR WX POTENTIAL. LATER
SHIFTS WILL NEED MONITOR STRENGTH OF THIS JET ALONG WITH TSRA
DEVELOPMENT TOWARD MORNING.
IN ADDITION TO THE SVR WX THREAT...PWATS VALUES RISE INTO THE 1.5"
RANGE. IF ANY TSRA BEGIN TO TRAIN OR BACK BUILD...FLASH FLOODING
IS POSSIBLE...ESPECIALLY ONCE THE LLJ INCREASES DURING THE EVENING
HRS.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 242 PM CDT SAT AUG 30 2014
POTENT COLD FRONT WILL HAVE SHIFTED THROUGH MUCH OF THE MPX CWFA BY
DAYBREAK MON MORNING...WITH IT PROGRESSING JUST BARELY INTO WRN WI
AND SERN MN. SOME LINGERING SHOWERS/TSTMS WILL LIKELY BE ONGOING IN
FAR ERN PORTIONS OF THE CWFA AT THE START OF THIS PERIOD BUT
STRENGTH WILL BE FAIRLY WEAK...MEANING THAT ANY SEVERE POTENTIAL
WILL HAVE BEEN TAPPED BY THIS POINT. SUPPORTING THIS FACT IS THAT
THE UPPER LEVEL TROF AXIS WILL BE E OF THE CWFA AND THE FRONT WILL
BE RATHER STRETCHED OUT BETWEEN THE MAIN LOW PRES CENTER OVER WRN
ONTARIO PROVINCE AND A SECONDARY LOW PRES CENTER OVER KS. HIGH
PRES WILL THEN NUDGE IN FROM THE CENTRAL PLAINS WHILE FLOW ALOFT
IS MAINLY ZONAL WNW-ESE. A FEW BUCKLES IN THE FLOW WITHIN A
PERSISTENTLY DEEP MOIST ATMO MAY PRODUCE ISOLATED SHOWERS FROM TIME TO
TIME LATE MON THRU MUCH OF WED. THIS AREA OF HIGH PRES WILL SHIFT
E INTO THE MID-MISS RIVER VALLEY THEN OHIO VALLEY BY WED MORNING...
ALLOWING FOR A WARMER AND MORE MOIST SLY RETURN FLOW TO DEVELOP BY
MIDDAY WED.
THE ADDITIONAL MOISTURE WILL PRECEDE THE ARRIVAL OF A SLOW-MOVING
LOW PRES CENTER FROM THE NRN ROCKIES WED NIGHT. THIS LOW WILL
STALL OUT OVER THE NRN PLAINS...HELPING SET UP A SFC FRONTAL
BOUNDARY EXTENDING FROM WRN MN ACROSS THE ROCKIES. THIS BOUNDARY
WILL ACT AS A LOW-LEVEL CONFLUENT ZONE AND AID IN PRECIPITATION
DEVELOPMENT THU THROUGH SAT. NOT LOOKING FOR A LOT IN THE WAY OF
QPF NOR STORM STRENGTH...BUT FINDING SOLID DRY TIME WILL BE
DIFFICULT DUE TO SCATTERED SHOWERS FOR MUCH OF THE LATTER PORTION
OF THE WEEK. CANNOT SAY ANY DAY WILL BE A WASHOUT ATTM...BUT ALSO
HARD TO PINPOINT ONE TIMEFRAME OVER ANOTHER FOR BEST TIMING OF
PRECIPITATION.
TEMPERATURES LOOK TO GO ON A SLOW WARMING TREND THRU THE
WORKWEEK...CLIMBING THROUGH THE MID-UPR 70S INTO THE LWR 80S BY
FRI. HOWEVER...THERE WILL BE PLENTY OF CLOUD/RAIN COMPLICATIONS
WHICH ON SMALL SCALES MAY CREATE SOME VARIETY WITH MAX/MIN TEMPS.
BY SAT... THIS LOW PRES COMPLEX WILL SHIFT S AND E OF THE MPX
CWFA...ALLOWING FOR A COOLING OF TEMPERATURES FOR NEXT WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1233 AM CDT SUN AUG 31 2014
WITH THE HRRR ALONG WITH VIRTUALLY ALL OTHER CAMS SHOWING A BAND
OF SHRA/TSRA WORKING ACROSS MN WITH INITIAL ARRIVAL OF THE
LLJ...STARTED TO INTRODUCE VCSH IN THE MORNING TO ALL MN
TERMINALS. THIS SCENARIO SEEMS VERY PLAUSIBLE GIVEN THE FACT THAT
WE ARE CURRENTLY SEEING SCT ACTIVITY CLEAR DOWN INTO NC NEB. THE
ATMO HAS ALREADY TIPPED ITS HAND WHEN IT COMES TO FOG AT EAU...SO
HAVE LEFT THEM DOWN THE REST OF THE NIGHT. WITH THAT SAID...THERE
IS STILL A FAIR AMOUNT OF CLOUD COVER IN THE 050-080 LEVEL IN ERN
MN INTO WRN WI...WHICH MAY LEAD TO A BIT OF VARIABILITY IN THE
VSBYS AT RNH/EAU AS THEY SKIP BETWEEN 050-080 CLOUDS AND CLEAR
SKIES /WHICH WILL BE ACCOMPANIED BY FOG/. STILL A GOOD DEGREE OF
VARIABILITY WITH THE 00Z CAMS IN TERMS OF AFTERNOON
CONVECTION...BUT FORECAST SOUNDINGS DO SHOW A GOOD DEGREE OF
CAPPING TO OVERCOME FIRST...SO DID DELAY AFTERNOON TS MENTION AN
HOUR OR TWO FROM WHAT THE 00Z TAF HAD. IN ADDITION...REMOVED THE
AFTERNOON TS MENTION AT AXN...WITH AXN LOOKING TO MOST LIKELY BE
WEST OF THAT ROUND OF STORMS.
KMSP...BEGINNING TO GAIN CONFIDENCE IN AT LEAST SCT SHRA/TSRA IN
THE METRO AREA THIS MORNING...SO HAVE STARTED WITH INTRODUCING A
VCSH GROUP. BY 9Z...SHOULD HAVE A BETTER FEEL FOR WHETHER OR NOT
WE WILL SEE ANYTHING...SO WILL WAIT FOR THAT AMD TO SEE IF WE NEED
ANY STRONGER SHRA/TSRA MENTION. 00Z TAF LOOKED TO HAVE GOOD TIMING
FOR POTENTIAL AFTERNOON TSRA...SO STUCK WITH THAT. IS POTENTIAL
THAT MSP COULD GET SPLIT BY ACTIVITY TODAY...WITH STRONGER
ACTIVITY REMAINING SOUTH OF THE FIELD WITH BETTER LLJ FORCING DOWN
IN IOWA AND GOING NORTH OF THE FIELD...CLOSER TO THE SFC LOW THAT
WILL BE GOING ACROSS NRN MN. STILL...GIVEN THE STRENGTH OF THE
FRONT/FORCING...ODDS LOOK BETTER THAT MSP WILL SEE SOME TSRA
ACTIVITY THAN STORMS MISSING THE AIRPORT.
/OUTLOOK FOR KMSP/
MON...MVFR/TSRA ENDING EARLY. VFR BY AFTERNOON WINDS WNW 5-10 KTS.
TUE...VFR. WINDS WSW 5-10 KTS.
WED...VFR. CHC MVFR/TSRA LATE. WINDS S 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...JLT
LONG TERM...JPC
AVIATION...MPG
AREA FORECAST DISCUSSION
NWS BILLINGS MT
330 AM MDT SUN AUG 31 2014
.SHORT TERM...VALID FOR TDY AND MON...
BROAD CYCLONIC FLOW WILL CONTINUE TO PREVAIL OVER OUR REGION THE
NEXT COUPLE OF DAYS. WE WILL HAVE A COUPLE OF DISTURBANCES WITHIN
THE FLOW ALOFT TRACK THROUGH THE REGION PRODUCING PERIODS OF
SHOWERS AND SCATTERED THUNDERSHOWERS. A SEASONABLY COOL AIR MASS
WILL REMAIN ENTRENCHED OVER THE REGION AS WELL KEEPING HIGHS ABOUT
10 DEGREES COOLER THAN NORMAL.
AS FOR ADJUSTMENTS IN THIS PACKAGE...JET MAX ON THE FRONT END OF
BROADER TROUGH IS WEAKER THAN THE ONE ON THE BACKSIDE WHICH SHOULD
KEEP SOME OF THE ENERGY DIGGING SOUTH EARLY TODAY. THIS WILL KEEP
THE BEST LIFT GENERALLY SOUTH IN NW WYOMING. ONLY THE RAP AND HRRR HAS
PICKED UP ON THIS SO FAR WITH THE GFS/WRF/ECMWF ALL OVERPLAYING
THE PRECIPITATION TOO FAR NORTH. HOWEVER...WE WILL SEE INSTABILITY
SHOWERS DEVELOP AS THE COLD POOL MOVES OVER THE WEST THIS
AFTERNOON. WE MAY SEE A BETTER CHANCE OF PRECIPITATION ON THIS
SIDE OF THE STATELINE BY AFTERNOON AS ENERGY TURNS NORTHEAST ON
TROUGHS FRONT SIDE. SO HAVE ADJUSTED HIGHEST POPS SOUTHWARD THIS
MORNING...AND HIT THE SE SECTION HARDEST LATE MORNING TO THIS
AFTERNOON. ANOTHER SHORT WAVE COMES THROUGH THIS EVENING AND
AFFECTS MAINLY OUR WESTERN TERRAIN BEFORE SPREADING SHOWERS TO THE
SOUTHEAST THROUGH MONDAY. TEMPERATURES WILL REMAIN ON THE COOL
SIDE WITH LITTLE CHANGE TO INHERITED FORECASTS. BT
.LONG TERM...VALID FOR TUE...WED...THU...FRI...SAT...
RELATIVELY MINOR CHANGES TO THE EXTENDED PERIOD THIS MORNING.
ALTHOUGH MODELS ARE IN GOOD AGREEMENT WITH REGARD TO THE OVERALL
PATTERN...TIMING REMAINS A BIT OF AN ISSUE...AND LITTLE HAS
CHANGES FROM PREVIOUS MODELS RUNS. THE TIMING PROBLEMS HAVE
NECESSITATED A MORE BROAD BRUSH APPROACH TO POPS THROUGHOUT THE
PERIOD.
THE EXTENDED FORECAST REMAINS CONSISTENT...STARTING OFF QUIET FOR
WEDNESDAY...WITH ZONAL DOWNSLOPE FLOW ACROSS THE AREA. CONDITIONS
BEGIN TO CHANGE LATE WEDNESDAY AS SYSTEM OVER WESTERN CANADA DIGS
SOUTH AND FLOW TURNS SOUTHWEST OVER MONTANA. A COLD FRONT ALSO
PUSHES INTO THE REGION WEDNESDAY INCREASING THE CHANCES FOR
AFTERNOON AND EVENING THUNDERSTORMS. HAVE EXPANDED POPS COVERAGE
WEDNESDAY EVENING/NIGHT. BROAD TROF REMAINS IN CONTROL OVER THE
REGION INTO NEXT WEEKEND...WHICH KEEPS KEEPS SLIGHT PRECIP
POTENTIAL IN PLACE THROUGHOUT THE PERIOD AS WELL. PERSISTENCE OF
TROF WILL KEEP DAYTIME TEMPS WELL BELOW SEASONAL AVERAGE
THROUGHOUT THE EXTENDED PERIOD...WITH 60S AND 70S THROUGHOUT THE
PERIOD. AAG
&&
.AVIATION...
SCATTERED SHOWERS ARE EXPECTED ACROSS MUCH OF THE REGION TODAY AS
ANOTHER DISTURBANCE CROSSES THE AREA. AREAS OF MVFR AND FREQUENT
MOUNTAIN OBSCURATIONS CAN BE EXPECTED THROUGHOUT THE DAY. AAG
&&
.PRELIMINARY POINT TEMP/POPS...
TDY MON TUE WED THU FRI SAT
-------------------------------------------------------
BIL 069 051/070 050/078 054/077 050/069 049/069 050/074
3/T 32/T 00/U 12/T 22/T 22/T 22/T
LVM 066 044/070 043/079 046/077 043/068 044/069 045/076
4/T 42/T 00/U 12/T 22/T 22/T 23/T
HDN 071 051/072 050/080 053/081 051/072 051/073 050/077
3/T 32/T 00/U 12/T 22/T 22/T 22/T
MLS 074 052/074 052/079 054/080 053/071 053/072 052/075
2/T 22/T 00/U 11/U 12/T 22/T 22/T
4BQ 070 051/071 051/080 053/083 052/072 051/073 051/076
4/T 23/T 00/U 12/T 22/T 22/T 22/T
BHK 072 050/072 048/077 051/080 050/073 049/070 049/073
4/T 12/T 00/U 12/T 22/T 22/T 22/T
SHR 066 047/069 046/080 050/083 049/073 048/075 048/078
5/T 33/T 00/U 12/T 22/T 22/T 23/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
311 AM EDT SUN AUG 31 2014
.SYNOPSIS...
STRENGTHENING BERMUDA HIGH PRESSURE OFFSHORE WILL BRING SUMMERTIME
HEAT AND HUMIDITY THROUGH THE LABOR DAY WEEKEND WITH A FEW SHOWERS
AND THUNDERSTORMS POSSIBLE. A WEAK COLD FRONT WILL APPROACH FROM THE
NORTH LATE NEXT WEEK...BUT WILL LIKELY STALL BEFORE REACHING THE
AREA. BERMUDA HIGH PRESSURE AND A PIEDMONT TROUGH WILL REMAIN THE
DOMINANT FEATURES INTO NEXT WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 AM SUNDAY...SURFACE HIGH PRESSURE COVERS MUCH OF THE WESTERN
AND CENTRAL ATLANTIC OCEAN. THE UPPER LEVEL RIDGE IS CENTERED JUST
OFF THE CAROLINA COAST AND SHOULD KEEP ANY SYNOPTIC IMPULSES
DEFLECTED AWAY TO OUR NORTH AND WEST. 850 MB TEMPERATURES AROUND
+18C THIS AFTERNOON SHOULD RESULT IN HIGH TEMPERATURES IN THE MID
90S FROM MARION AND FLORENCE WESTWARD INTO DARLINGTON COUNTY.
ONSHORE WINDS CLOSER TO THE COAST SHOULD KEEP TEMPERATURES A LITTLE
COOLER...GENERALLY IN THE UPPER 80S TO LOWER 90S.
ALTHOUGH THERE IS CONSIDERABLE DRY AIR ALOFT DUE TO THE UPPER RIDGE
(COLUMN PRECIP WATER VALUES ARE ONLY 1.5 INCHES) VERY RICH MOISTURE
EXISTS IN THE LOWEST LEVELS OF THE ATMOSPHERE. DEWPOINTS IN THE MID
70S THIS MORNING WILL FORTUNATELY MIX DOWN TO NEAR 70 THIS AFTERNOON
INLAND...BUT THAT WILL STILL BE ENOUGH TO PUSH HEAT INDICES TO
100-103 DEGREES ACROSS MOST OF OUR FORECAST AREA. THIS MOISTURE MAY
ALSO FUEL WIDELY SCATTERED SHOWERS NEAR THIS COAST LATER THIS
MORNING...PROBABLY BECOMING LESSER IN COVERAGE THIS AFTERNOON AS
DRIER AIR MIXES DOWNWARD. FORECAST POPS RANGE FROM 20-30 PERCENT...
VIRTUALLY ALL EAST OF I-95.
ANY LINGERING DAYTIME CUMULUS SHOULD QUICKLY DIE AWAY THIS
EVENING... WITH ONLY A LITTLE PATCHY FOG OR LOW STRATUS EXPECTED TO
DEVELOP OVERNIGHT. LOWS SHOULD FALL INTO THE LOWER 70S FOR MOST
LOCALES...A FEW DEGREES WARMER NEAR THE BEACHES.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 3 AM SUNDAY...BERMUDA HIGH AND STRENGTHENING PIEDMONT TROUGH
WILL BE THE MAIN SURFACE FEATURES THROUGH THE PERIOD. ALOFT A FLAT
MID LEVEL RIDGE WILL EXTEND ACROSS MUCH OF THE SOUTHERN CONUS. DEEP
WESTERLY FLOW IN THE MID LEVELS WILL PUSH TROPICAL MOISTURE
EXPANDING NORTH FROM THE WESTERN GULF OF MEXICO OVER THE REGION MON
AND TUE. INCREASING MOISTURE ALOFT ALONG WITH LOW LEVEL MOISTURE
ADVECTION AROUND WEST SIDE OF BERMUDA HIGH WILL PUSH PRECIPITABLE
WATER VALUES OVER 2 INCHES FOR MUCH OF THE PERIOD.
FLAT MID LEVEL PATTERN MEANS LITTLE TO NO FORCING ALOFT WILL BE
PRESENT. HOWEVER THE COMBINATION OF LOW LEVEL MOISTURE AND SURFACE
HEATING WILL PUSH ML CAPE VALUES TO 1K-2K J/KG FOR MON AND OVER 2K
J/KG ON TUE. CONVECTION WILL INITIALLY BE SLOW TO DEVELOP BUT ONCE
SEA BREEZE AND PIEDMONT TROUGH TAKE SHAPE SHOWERS AND THUNDERSTORMS
SHOULD START POPPING UP. WILL MAINTAIN CHC POP FOR EACH AFTERNOON
BUT WITH SLIGHTLY HIGHER VALUES ON TUE GIVEN SLIGHTLY HIGHER CAPE
VALUES.
TEMPERATURES WILL RUN ABOVE CLIMO THROUGH THE PERIOD. HIGHS WILL
RANGE FROM UPPER 80S ALONG THE IMMEDIATE COAST TO MID 90S INLAND.
LOWS WILL BE IN THE LOW TO MID 70S.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 3 AM SUNDAY...BERMUDA HIGH AND PIEDMONT TROUGH ALONG WITH
ELONGATED MID LEVEL RIDGE WILL REMAIN THE SIGNIFICANT FEATURES
THROUGH THE PERIOD. A COUPLE COLD FRONTS WILL TRY AND MAKE A RUN TO
THE AREA DURING THE NEXT WEEK BUT THEY ARE LIKELY TO STALL AND WASH
OUT JUST NORTH OF THE FORECAST AREA. THE SURFACE AND MID LEVEL
PATTERNS ARE NOT ONES THAT GENERALLY SUPPORT FRONTS MOVING INTO AND
SOUTH OF THE CAPE FEAR REGION. PRECIPITABLE WATER VALUES WILL REMAIN
AROUND 2 INCHES THROUGH THE END OF THE WEEK. DIURNAL HEATING AND
SOUTHWEST FLOW WILL RESULT IN ML CAPE VALUES ABOVE 2K J/KG FOR MUCH
OF THE PERIOD. WEAK GRADIENT WILL ALLOW SEA BREEZE DEVELOPMENT AND
PIEDMONT TROUGH SHOULD BE WELL DEFINED. TYPICAL SUMMER PATTERN WITH
NEAR CLIMO PWATS AND TEMPERATURES NEAR TO SLIGHTLY ABOVE CLIMO
SUGGEST POP WILL BE NEAR CLIMO FOR MUCH OF THE PERIOD...30 PERCENT.
&&
.AVIATION /07Z SUNDAY THROUGH THURSDAY/...
AS OF 06Z...STILL EXPECT MVFR/IFR CIGS TO DEVELOP EARLY THIS MORNING
WITH THE BEST CHANCES FOR IFR INLAND AT KLBT/KFLO. HAVE BACKED OFF
THE FOG A BIT GIVEN THE INCREASING DEBRIS CLOUDS SPREADING INTO OUR
AREA. WOULD NOT RULE OUT TEMPO IFR VSBYS INLAND...BUT MVFR SEEMS
MORE LIKELY ATTM. EXPECT PERIODS OF MVFR CIGS ALONG THE COAST
BEGINNING AROUND DAYBREAK...WITH THE POTENTIAL FOR SOME ISOLATED
SHOWERS MOVING ONSHORE AS WELL. THE HRRR MODEL SHOWS A FEW SHOWERS
SKIRTING THE COAST THIS MORNING...SO WILL MAINTAIN VCSH FOR
KILM/KCRE/KMYR. THE MVFR CIGS MAY LINGER THROUGH MUCH OF THE
MORNING...BUT CONDITIONS WILL IMPROVE TO VFR BY MIDDAY AND PERSIST
THROUGH THE REST OF THE PERIOD. WINDS WILL BE SOUTH 6-10 KT DURING
THE DAY...POSSIBLY A BIT HIGHER ALONG THE COAST. COULD SEE SOME
ISOLATED SHOWERS ALONG THE SEABREEZE FONT IN THE AFTN...BUT
CONFIDENCE IN TIMING/LOCATION IS TOO LOW TO MENTION IN THE TAFS.
EXTENDED OUTLOOK...INCREASING CHANCES FOR AFTN SHOWERS/TSTMS MONDAY
THROUGH THURSDAY WITH BRIEF AND LOCALIZED PERIODS OF MVFR POSSIBLE.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 AM SUNDAY...SURFACE HIGH PRESSURE COVERS MOST OF THE WESTERN
AND CENTRAL ATLANTIC OCEAN. THIS SHOULD PRODUCE A SOUTH-SOUTHEAST
WIND TODAY...VEERING MORE SOUTHWESTERLY TONIGHT. SEAS CURRENTLY
AROUND 2 FEET MAY OCCASIONALLY REACH 3 FEET IN A COMBINATION OF
SOUTHEASTERLY SWELL AND LOCAL WIND WAVES...WITH ANY SCATTERED
MORNING SHOWERS EXPECTED TO DISSIPATE BY EARLY AFTERNOON.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 3 AM SUNDAY...BERMUDA HIGH AND PIEDMONT TROUGH WILL MAINTAIN
SOUTHWEST FLOW OVER THE WATERS THROUGH THE PERIOD. SPEEDS 10 KT OR
LESS WILL INCREASE TO A SOLID 15 KT EACH AFTERNOON AND EVENING AS
THE PIEDMONT TROUGH STRENGTHENS. SEAS IN THE 2 TO 3 FT RANGE.
LONG TERM /WEDNESDAY THROUGH THURSDAY/...
AS OF 3 AM SUNDAY...MINIMAL CHANGE FOR THE LONG TERM PERIOD. BERMUDA
HIGH REMAINS IN PLACE AS DOES THE PIEDMONT TROUGH. LATE IN THE
PERIOD A WEAKENING COLD FRONT WILL APPROACH FROM THE NORTH BUT IS
EXPECTED TO STALL BEFORE REACHING THE AREA. SOUTHWEST FLOW AROUND 10
KT WILL INCREASE TO A SOLID 15 KT EACH AFTERNOON AND EVENING. SEAS
WILL RUN 2 TO 3 FT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...TRA
SHORT TERM...III
LONG TERM...III
AVIATION...BJR/TRA
AREA FORECAST DISCUSSION
NWS RALEIGH NC
220 AM EDT SUN AUG 31 2014
.SYNOPSIS...HIGH PRESSURE WILL EXTEND OVER THE REGION THROUGH THE
MIDDLE OF NEXT WEEK. A WEAKENING COLD FRONT WILL APPROACH THE REGION
FROM THE NORTH ON WEDNESDAY... BEFORE RETREATING THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1045 PM SATURDAY...
THE LATEST SURFACE ANALYSIS CONTINUED TO SHOW A SLACK GRADIENT OVER
CENTRAL NORTH CAROLINA. RADAR SHOWED EARLIER SHOWERS HAD
DIMINISHED...AS THE SEA BREEZE HAD MOVED NORTH AND WEAKENED WHILE
VERY DRY MID-LEVEL AIR MOVED EAST ACROSS CENTRAL AND EASTERN NORTH
CAROLINA ON WATER VAPOR IMAGERY. K INDICES SHOULD FALL INTO THE
TEENS AS BUFR SOUNDINGS FROM THE GFS AND NAM ALONG WITH RAP
SOUNDINGS SHOW AN OVERALL STABLE AIR MASS THEN.
SOME OF THE TEMPERATURES ACROSS CENTRAL NORTH CAROLINA FELL QUICKLY
DURING MID-EVENING...BUT WITH SOME THIN CIRRUS MOVING EAST FROM DEEP
CONVECTION WELL UPSTREAM...ALONG WITH SURFACE DEW POINTS AROUND 70
TO THE LOWER 70S IN MOST LOCATIONS...TEMPERATURES ARE NOT EXPECTED
TO CONTINUE THAT RAPID FALL. LOWS SHOULD MOSTLY BE WITHIN A DEGREE
OR TWO OF 70. SOME LOW CLOUDS REMAIN POSSIBLE LATE TONIGHT
PARTICULARLY AS NOTED ON NAM BUFR SOUNDINGS AND THE SREF
PROBABILISTIC GUIDANCE...AND ALLUDED TO MORE ON THE GFS 18Z MOS
GUIDANCE OUTPUT FROM ITS EARLIER...MORE OPTIMISTIC 12Z GUIDANCE. THE
LATEST HRRR WRF WOULD SUGGEST A BETTER POTENTIAL FOR LOW CLOUDS LATE
TONIGHT IN A NARROW AXIS ALONG AND WEST OF U.S. 1...WHERE SREF
PROBABILITIES ARE A LITTLE HIGHER RELATIVE TO THE REST OF THE AREA
AND CLOSER TO THE HIGHER 925MB WINDS. THOSE 925MB WINDS SEEM A
LITTLE HIGH FOR FOG IN MOST PLACES...TO 20KT TOWARD THE TRIAD LATE
TONIGHT...BUT THE LOWER VALUES OF 10 TO 15KT TOWARD INTERSTATE 95
ALONG WITH EXPECTED DEW POINTS IN THE LOWER 70S COULD ALLOW A LITTLE
MORE NOTICEABLE FOG IN PATCHES TOWARD THERE LATE.
&&
.SHORT TERM /SUNDAY AND SUNDAY NIGHT/...
AS OF 230 PM SATURDAY...
A SHORT WAVE TROUGH OVER THE MS RIVER VALLEY TO START THE DAY WILL
LIFT TO THE NORTHEAST INTO THE OH VALLEY THROUGH SUNDAY NIGHT.
HOWEVER...ITS ASSOCIATED ENERGY AND DEEP MOISTURE PLUME (EMANATING
FROM THE GULF) WILL LARGELY REMAIN WEST AND NORTH OF CENTRAL NC. IN
ADDITION...THE SUBTROPICAL RIDGE CENTERED OVER THE SOUTHEAST COAST
SHOULD ALSO HELP KEEP THE BETTER RAIN CHANCES WEST OF THE AREA.
THEREFORE...WILL CONTINUE THE FORECAST THINKING OF ONLY ISOLATED TO
WIDELY SCATTERED SHOWERS/STORMS...WITH THE BEST CHANCES ACROSS THE
WEST DUE TO THE PROXIMITY OF THE ABOVE FEATURES. TEMPS WILL CONTINUE
TO BE ABOVE NORMAL...WITH HIGHS GENERALLY IN THE LOWER 90S AND
OVERNIGHT LOWS AROUND 70 DEGREES.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 220 AM SUNDAY...
SUMMERTIME SUBTROPICAL RIDGING REMAINS THE MAIN THEME OF OUR
FORECAST THIS WEEK. THE UPPER RIDGE IS FORECAST TO EXPAND AND
STRENGTHEN EARLY TO MID WEEK... THEN CONTRACT LATE WEEK INTO THE
WEEKEND. HOWEVER... THE RIDGING IS EXPECTED TO REMAIN FIRMLY IN
PLACE OVER THE SOUTHERN AND SOUTHEASTERN STATES THROUGH THE WEEK.
MOISTURE... DAILY INSTABILITY... AND A LEE TROUGH/WEAKENING SURFACE
COLD FRONTS (WED-THU)... THEN AGAIN TOWARD THE WEEKEND WILL PROVIDE
SPARK FOR MAINLY AFTERNOON AND EARLY EVENING THUNDERSTORMS WED-SAT.
SENSIBLE WEATHER WILL INCLUDE AN EXTENDED PERIOD OF HOT/HUMID
WEATHER THROUGH THE WEEK. DAILY LOWS 70-75. HIGHS 90-95. THESE
READINGS WILL BE AROUND 5 DEGREES ABOVE NORMAL. 20 POP TUE... WILL
INCREASE TO 30-50 PERCENT DURING THE AFTERNOON AND EARLY EVENINGS
WED-SAT.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
AS OF 751 PM SATURDAY...
VFR CONDITIONS WILL CONTINUE THROUGH THE EVENING. LOW LEVEL MOISTURE
REMAINS HIGH ACROSS THE AREA WITH LIGHT SURFACE WINDS... AND IFR
CONDITIONS WITH STRATUS... AND POSSIBLY SOME PATCHY FOG.... ARE
EXPECTED TO DEVELOP IN THE EARLY MORNING HOURS SUNDAY AT
KRDU...KRWI...AND KFAY... WHERE DEWPOINTS ARE HIGHEST. MVFR
CONDITIONS ARE POSSIBLE AT KGSO AND KINT. CONDITIONS WILL RETURN TO
VFR AFTER 12Z SUNDAY... WITH A FEW SHOWERS/THUNDERSTORMS POSSIBLE IN
THE AFTERNOON.
OUTLOOK...A SUMMERTIME PATTERN WILL PERSIST THROUGH EARLY/MID NEXT
WEEK...WITH ISOLATED TO SCATTERED AFTERNOON/EVENING CONVECTION AND A
POTENTIAL FOR EARLY MORNING FOG/STRATUS.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...PWB
NEAR TERM...DJF
SHORT TERM...KRD
LONG TERM...PWB
AVIATION...SEC/KRD
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1259 AM EDT SUN AUG 31 2014
.SYNOPSIS...
STRENGTHENING BERMUDA HIGH PRESSURE OFFSHORE WILL BRING SUMMERTIME
HEAT AND HUMIDITY THROUGH THE LABOR DAY WEEKEND WITH A FEW SHOWERS
AND THUNDERSTORMS POSSIBLE. A WEAK COLD FRONT WILL APPROACH FROM THE
NORTH LATE NEXT WEEK...BUT WILL LIKELY STALL BEFORE REACHING THE
AREA. BERMUDA HIGH PRESSURE AND A PIEDMONT TROUGH WILL REMAIN THE
DOMINANT FEATURES INTO NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 100 AM SATURDAY...NO SIGNIFICANT CHANGES ARE NEEDED TO THE
FORECAST. PREVIOUS DISCUSSION FROM 1000 PM FOLLOWS...
MUCH LIKE THE PAST COUPLE OF NIGHTS...A FEW SHOWERS HAVE BEGUN TO
DEVELOP OFFSHORE. SOME OF THE HIGHER RESOLUTION MODELS ARE SHOWING
THESE SHOWERS FLIRTING WITH THE IMMEDIATE COAST OVERNIGHT. GIVEN THE
PREVAILING SOUTHERLY FLOW...THE HIGHEST RISK FOR SHOWERS WILL BE
ACROSS BRUNSWICK COUNTY AND THE SOUTHERN PORTIONS OF NEW HANOVER
COUNTY.
WILL INCLUDE PATCHY LATE NIGHT FOG ACROSS MOST OF THE AREA...
GREATEST COVERAGE IS EXPECTED AWAY FROM THE IMMEDIATE COAST WHERE
MIXING WILL BE LEAST. MUCH LIKE LAST NIGHT...EXPECT A FOG AND
STRATUS MIX LATE. HIGH LEVEL CONVECTIVE DEBRIS CLOUDINESS WILL
CONTINUE TO SPILL ACROSS THE FORECAST AREA. THESE CLOUDS ARE FROM
UPSTREAM CONVECTION AND WILL BE MAINLY THIN ACROSS THE EASTERN
CAROLINAS OVERNIGHT.
LIGHT TO CLAM WINDS AND ONLY A HINT OF A WEAK NOCTURNAL JET SHOULD
ALLOW FOR AT LEAST SOME RADIATIONAL COOLING. DID NOT STRAY TOO FAR
FROM THE LOWS OF SAT...WHICH WILL PUT MOST LOCATIONS IN THE LOWER TO
MID 70S OVERNIGHT.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
AS OF 330 PM SATURDAY...MODELS REMAIN SIMILAR AND VIGILANT WITH
REGARD TO KEEPING RIDGING ALOFT ACROSS THE FORECAST AREA THRU-OUT
THE SHORT TERM PERIOD. SOME FLATTENING DOES OCCUR DURING LATE IN
THE SHORT TERM PERIOD AS SUCCESSIVE MID-UPPER LEVEL S/W TROFS PUSH
BASICALLY FROM WEST TO EAST ACROSS THE U.S....WITH THE BEST
DYNAMICS ASSOCIATED WITH EACH OF THEM REMAINING NORTH OF THE FA.
NEVERTHELESS...WITH TIME...THEY DO PARTIALLY ERODE THE MID-UPPER
RIDGING ACROSS THE FA BY DAYBREAK TUE.
AT THE SFC...THE STALLED E-W ORIENTED FRONTAL BOUNDARY ACROSS
CENTRAL NC...WILL SLOWLY DISSIPATE AS IT RETURNS BACK TO THE NORTH
DURING THIS PERIOD. THE RIDGE AXIS EXTENDING FROM THE 1025+ WESTERN
ATLANTIC HIGH...WILL BECOME THE DOMINATE WX FEATURE TO AFFECT THE
EASTERN CAROLINAS MONDAY THRU TUESDAY. IN ADDITION...THE PIEDMONT
TROF ACROSS THE CENTRAL CAROLINAS WILL BECOME MORE PREVALENT BY
LABOR DAY AND BEYOND.
AS FOR PCPN CHANCES...THE AFTERNOON/EVENING SEA BREEZE AND
PREVALENT PIEDMONT TROF WILL PROVIDE THE FORCING FOR DIURNALLY
DRIVEN CONVECTION BOTH DAYS. MODELS DO INDICATE A BETTER DEFINED
PIEDMONT TROF BY MONDAY AND THUS THE OVERALL POP SCHEME WILL BE
ADVERTISED WITH A SLIGHTLY HIGHER CHANCE MONDAY OVER SUNDAY. LATEST
SREF ALSO INDICATE A HIGHER POP FOR MONDAY OVER TUE. SEE NO REASON
TO GO AGAINST THIS LAYOUT OF POPS. AS FOR DAILY MAX AND MIN
TEMPS...WILL STAY CLOSER TO THE NAM MOS GUIDANCE DUE TO ITS BETTER
PERFORMANCE THE PAST 5 DAYS WHEN COMPARED TO THE OTHER AVBL MODEL
MOS GUIDANCE.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 330 PM SATURDAY...MID TO UPPER RIDGE HOLDING ON OVER
SOUTHERN CONUS WHILE SHORTWAVES RIDE BY IN NORTHERN STREAM FLOW.
THESE SHORTWAVES WILL DRIVE A FEW COLD FRONTS EAST BUT TRAILING
END SHOULD REMAIN NORTH OF LOCAL AREA. THESE BOUNDARIES MAY MOVE
CLOSE ENOUGH TO AFFECT THE WINDS OR PRODUCE SOME DRIER AIR TO MOVE
IN ALOFT. OVERALL BERMUDA HIGH PRESSURE TO THE EAST AND PIEDMONT
TROUGH TO THE WEST WILL REMAIN THE MAIN PLAYERS THROUGH THE
WEEK...MAINTAINING A WARM HUMID AIR MASS. EXPECT LOCALIZED
CONVECTION POSSIBLE EACH DAY WITH FOCUS ALONG SEA BREEZE BOUNDARY
AND PIEDMONT TROUGH INLAND. A WEAK SOUTHERLY RETURN FLOW SHOULD BE
ENHANCED BY SEA BREEZE EACH AFTERNOON. DEWPOINT TEMPS UP ABOVE 70
WILL KEEP OVERNIGHT LOWS IN 70S AND DAYTIME HIGHS WILL REACH CLOSE
TO 90 ALONG THE COAST AND INTO THE MID 90S INLAND.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AS OF 06Z...STILL EXPECT MVFR/IFR CIGS TO DEVELOP EARLY THIS MORNING
WITH THE BEST CHANCES FOR IFR INLAND AT KLBT/KFLO. HAVE BACKED OFF
THE FOG A BIT GIVEN THE INCREASING DEBRIS CLOUDS SPREADING INTO OUR
AREA. WOULD NOT RULE OUT TEMPO IFR VSBYS INLAND...BUT MVFR SEEMS
MORE LIKELY ATTM. EXPECT PERIODS OF MVFR CIGS ALONG THE COAST
BEGINNING AROUND DAYBREAK...WITH THE POTENTIAL FOR SOME ISOLATED
SHOWERS MOVING ONSHORE AS WELL. THE HRRR MODEL SHOWS A FEW SHOWERS
SKIRTING THE COAST THIS MORNING...SO WILL MAINTAIN VCSH FOR
KILM/KCRE/KMYR. THE MVFR CIGS MAY LINGER THROUGH MUCH OF THE
MORNING...BUT CONDITIONS WILL IMPROVE TO VFR BY MIDDAY AND PERSIST
THROUGH THE REST OF THE PERIOD. WINDS WILL BE SOUTH 6-10 KT DURING
THE DAY...POSSIBLY A BIT HIGHER ALONG THE COAST. COULD SEE SOME
ISOLATED SHOWERS ALONG THE SEABREEZE FONT IN THE AFTN...BUT
CONFIDENCE IN TIMING/LOCATION IS TOO LOW TO MENTION IN THE TAFS.
EXTENDED OUTLOOK...INCREASING CHANCES FOR AFTN SHOWERS/TSTMS MONDAY
THROUGH THURSDAY WITH BRIEF AND LOCALIZED PERIODS OF MVFR POSSIBLE.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 100 AM SUNDAY...TWO MINOR CHANGES HAVE BEEN MADE TO THE
FORECAST WITH THIS EARLY MORNING NEAR-TERM UPDATE. THE FIRST WAS TO
TRIM BACK SEA HEIGHT FORECASTS BASED ON LATEST BUOY DATA SHOWING
NOTHING HIGHER THAN 2 FEET NEAR OR OFFSHORE. THE OTHER CHANGE WAS TO
INDICATE IN THE HIGH-RESOLUTION GRIDDED FORECAST A WEAK LANDBREEZE
DEVELOPING JUST BEFORE DAYBREAK WITH LIGHT NORTH TO NORTHWEST WINDS
NEAR THE BEACHES. PREVIOUS DISCUSSION FROM 1000 PM FOLLOWS...
HIGH PRESSURE OVER THE WESTERN ATLANTIC WILL KEEP A SOUTHERLY FLOW
ACROSS THE WATERS OVERNIGHT...UP TO AROUND 10 KT. SEAS WILL REMAIN
NEAR 3 FT.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 330 PM SATURDAY...THE SFC PRESSURE PATTERN FOR BOTH SUNDAY
AND LABOR DAY ILLUSTRATE THE RIDGE AXIS EXTENDING FROM THE WESTERN
ATLANTIC HIGH WILL REMAIN JUST SOUTH OF THE LOCAL WATERS. THIS
POSITIONING WILL RESULT WITH A SOUTH TO SOUTHWEST WIND DIRECTION
ACROSS THE WATERS...AND POSSIBLY BECOMING MORE WSW LATE IN THE
PERIOD. THE SFC PG WILL SLOWLY TIGHTEN-SOME ACROSS THE LOCAL
WATERS AS THE PIEDMONT TROF ACROSS THE EASTERN CAROLINAS BECOMES
BETTER ESTABLISHED. LOOK FOR WIND SPEEDS INITIALLY AROUND 10 KT AT
THE START...INCREASING TO 10 TO 15 KT OR POSSIBLY A SOLID 15 KT
WITH GUSTS AROUND 20 KT BY MONDAY AFTN AND NIGHT. A DECENT SEA
BREEZE CIRCULATION WILL SETUP EACH AFTN AND EVENG...AFFECTING THE
NEARSHORE WATERS WITHIN 10 NM FROM THE COAST WITH HIGHER WIND
SPEEDS.
SIGNIFICANT SEAS WILL RUN A SOLID 2 TO 3 FT...WITH 4 FOOTERS NOT
OUT OF THE QUESTION DURING THE PEAK OF THE SEA BREEZE EACH
DAY...BUT MORE-SO DURING MONDAY AFTN AND NIGHT DUE TO SOLID
SYNOPTIC WINDS AROUND 15 KT. A SOLID 2 FOOT EASTERLY GROUND SWELL
EXHIBITING 8 TO 10 SECOND PERIODS...WILL INITIALLY DOMINATE THE
SIGNIFICANT SEAS EARLY IN THE PERIOD. BUT AS SYNOPTIC AND
MESOSCALE DRIVEN WINDS INCREASE ACROSS THE AREA WATERS...LOOK FOR
AN INCREASE TO THE LOCALLY PRODUCED WIND WAVES TO COMBINE WITH THE
GROUND SWELL AND PRODUCE THOSE 4 FOOTERS BY LATE IN THIS SHORT
TERM PERIOD.
LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 330 PM SATURDAY...BERMUDA HIGH OFF SHORE AND PIEDMONT
TROUGH INLAND WILL MAINTAIN A PERSISTENT LIGHT SOUTHERLY RETURN
FLOW THROUGH MUCH OF THE WEEK AROUND 10 TO 15 KTS. THE FLOW WILL
BE ENHANCED BY THE SEA BREEZE EACH AFTN. THE WEAK SOUTHERLY PUSH
WILL KEEP SEAS 1 TO 3 FT WITH A SLIGHT CHOP EACH AFTN. WINDS MAY
LIGHTEN FURTHER TO LESS THAN 10 KTS BY THURS WITH A FURTHER DROP
IN SEAS DOWN TO 2 FT OR LESS
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...RJD/TRA
SHORT TERM...DCH
LONG TERM...RGZ
AVIATION...BJR/TRA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
359 AM CDT SUN AUG 31 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 358 AM CDT SUN AUG 31 2014
FOCUS IN THE SHORT TERM WILL BE ON THE EXITING RAINFALL THROUGH
THIS MORNING AND THE CHANCES FOR RAIN LATER TODAY.
THE HRRR MODEL HAS DONE A DECENT JOB OF FORECASTING PRECIPITATION
THROUGH THE NIGHT AND EARLY THIS MORNING AND POPS MIMIC THE 05 UTC
HRRR PRECIPITATION AS IT PROGRESSES NORTHEAST. MOST ALL HEAVY RAIN
HAS PUSHED EAST INTO EASTERN NORTH DAKOTA...HOWEVER A VERY THIN BAND
OF SHOWERS IS SLOWLY MOVING EAST ACROSS WESTERN NORTH DAKOTA. AS OF
0730 UTC THE BAND DROPPED HEAVY RAIN AT THE DICKINSON AIRPORT. DO
NOT EXPECT THIS BAND...AT LEAST THE HEAVY RAIN ASSOCIATED WITH
IT...TO LAST MUCH LONGER INTO THE MORNING HOURS.
LOOKING FORWARD TO THIS AFTERNOON AND TONIGHT MODELS AGREE ON A
BROAD TROUGH SETTING UP OVER THE NORTHERN PLAINS TODAY WITH A WEAK
SHORT WAVE MOVING THROUGH IN THE AFTERNOON AND NIGHT. THE 00 UTC
MODELS ARE HAVING A DIFFICULT TIME NAILING DOWN WHERE THE
PRECIPITATION WILL FALL EXACTLY...HOWEVER ONLY LIGHT TO MODERATE
SHOWERS ARE EXPECTED. AT THE MOST EXPECTING A SOME SCATTERED SHOWERS
AND A FEW RUMBLES OF THUNDER.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 358 AM CDT SUN AUG 31 2014
THE EXTENDED BEGINS WITH A COOL CYCLONIC FLOW ALOFT ACROSS THE
NORTHERN PLAINS MONDAY INTO TUESDAY. THIS SHOULD AT LEAST SUPPORT
SOME WIDELY SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS. HIGHS
MONDAY AND TUESDAY WILL BE A BIT COOL IN THE UPPER 60S TO LOWER
70S. BY WEDNESDAY THE FLOW ALOFT BECOMES MORE ZONAL AS THE
IN BETWEEN SHORTWAVE TROUGHS. BY THURSDAY THE GFS/ECMWF/GEM BRING
THE NEXT SHORTWAVE TROUGH INTO THE NORTHERN PLAINS WHICH IS
PRETTY CONSISTENT WITH THE PAST FEW MODEL RUNS. THE ECMWF/GEM ARE A
BIT MORE ROBUST IN QPF FORECAST FOR NORTH DAKOTA. LIKED THE
ALLBLEND VERSION OF POPS FOR WEDNESDAY NIGHT AT 30 POPS FOR NOW.
AFTER THURSDAY THE FLOW ALOFT BECOMES SEPARATED BETWEEN A NORTHERN
AND SOUTHERN STREAM FLOW WITH THE GFS MORE PRONOUNCED IN THE FLOW
SEPARATION AROUND A CUTOFF LOW OFF THE WEST COAST. THE BASIC
RESULT WILL BE A QUIET PERIOD FRIDAY INTO SATURDAY AS THE FLOW
MERGES ALOFT OVER THE NORTHERN PLAINS RESULTING IN WEAK SUDSIDENCE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1240 AM CDT SUN AUG 31 2014
0530Z A LINE OF THUNDERSTORMS WAS PROGRESSING EAST ALONG A FRONTAL
BOUNDARY OVER CENTRAL NORTH DAKOTA. KMOT-KBIS-KJMS WILL INITIALLY
BE IMPACTED BY THE STORMS. AFTER 08Z THE LINE WILL HAVE MOVED EAST
OF KMOT-KBIS AND THEN AFTER 10Z AT KJMS. NORTHWEST FLOW MAY BRING
IN SOME MVFR CEILINGS ESPECIALLY AFTER SUNRISE CENTRAL AND EAST.
OTHERWISE ONLY VERY ISOLATED SHOWERS DURING THE DAY SUNDAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...MM
LONG TERM...WAA
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
329 AM EDT SUN AUG 31 2014
.SYNOPSIS...
DEEP MOISTURE AND UPPER LEVEL DISTURBANCES PROVIDE ROUNDS OF
SHOWERS AND STORMS TODAY. WEAK FRONT CROSSES TUESDAY WITH SHOWERS
AND STORMS.
&&
.NEAR TERM /THROUGH TONIGHT/...
THROUGH THE EARLY AFTERNOON/18Z TIME FRAME TODAY...LEANED HEAVILY ON
THE HRRR MODEL GIVEN THAT IT HAD INITIALIZED VERY WELL. TYPICALLY
LIKE THE OUTPUT OF THIS MODEL WHEN THAT HAPPENS. ALSO...SINCE THE
NAM MATCHED UP FAIRLY WELL...DEFORMATION AND FRONTOGENESIS PROGS
PROVED VALUABLE IN THE PATTERN OF THE POP CONSTRUCTION THIS MORNING.
THIS HELPED TO ADD SOME DEFINITION TO THE PREVIOUS
FORECAST...PARTICULARLY OVER THE LOWLANDS SOUTH/EAST OF THE OHIO
RIVER.
AXIS OF DEEP MOISTURE DEPARTS TONIGHT...ALTHOUGH MAY STILL BE
HANGING ON IN THE MOUNTAINS BY 12Z MONDAY.
TEMPERATURES COME DOWN SIGNIFICANTLY FOR TODAY IN THE PERIODIC RAIN.
MAY NOT COME OUT OF THE 70S OVER SOUTHEAST OHIO. SOUTHERN MOUNTAIN
LOCATIONS IN THE EASTERN PORTION OF THE CWA COULD END UP WARMER THAN
THE OHIO RIVER SITES. THE MAV GUIDANCE HAS BEEN HANDS DOWN BETTER
THAN THE OTHERS AND LEANED ON THIS...BUT ALWAYS A LITTLE HESITANT
IN A DIFFERENT ATMOSPHERE.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
MODELS AGREE OUR AREA WILL BE BETWEEN TWO SIGNIFICANT SYSTEMS ON
MONDAY. WHILE DYNAMICS WILL BE AT A MINIMUM...A WARM AND HUMID
AIRMASS WILL CONTINUE FOR A THREAT OF SCATTERED AFTERNOON STORMS
MONDAY...AND MORE SUNSHINE WILL LEAD TO HIGH TEMPERATURES IN THE MID
TO UPPER 80S. WITH LOSS OF HEATING...ANY CONVECTION WILL DISSIPATE
QUICKLY EARLY MONDAY EVENING. IT WILL REMAIN MOSTLY PRECIP FREE
MONDAY NIGHT BEFORE THE NEXT SYSTEM IN THE FORM OF ANOTHER UPPER
TROUGH AND ASSOCIATED COOL FRONT AFFECT US TUESDAY. MODELS HAVE THE
UPPER TROUGH PROGRESSING EASTWARD ACROSS OUR AREA TUESDAY AND EARLY
TUESDAY NIGHT WITH A BAND OF SHOWERS AND STORMS. SO HIGH POPS
PROGRESSING FROM NORTHWEST TO SOUTHEAST TUESDAY INTO EARLY TUESDAY
NIGHT ARE IN ORDER. WHILE THE UPPER TROUGH EXITS TUESDAY NIGHT...THE
COOL FRONT WILL LOSE DEFINITION AS IT CROSSES THE AREA...AND
GRADUALLY BE REPLACED BY WEAK HIGH PRESSURE LATER TUESDAY NIGHT AND
WEDNESDAY. HEIGHTS RISE MODESTLY BEHIND THE UPPER TROUGH...BUT
MODELS STILL INDICATE ENOUGH MOISTURE AND INSTABILITY IN THE FAR
SOUTH FOR A SHOWER OR TWO TO CONTINUE INTO WEDNESDAY. LOOK FOR HIGH
TEMPERATURES TO STAY IN THE 80S FOR TUESDAY AND WEDNESDAY...BUT WITH
SOME DRIER AIR FILTERING INTO THE NORTH TUESDAY NIGHT AND
WEDNESDAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
LONG TERM PERIOD CAN GENERALLY BE CHARACTERIZED BY ZONAL FLOW ALOFT.
LEANED WPC FOR THE MOST PART WITH A FEW TWEAKS HERE AND THERE. WARM
AND MUGGY CONDITIONS WILL CONTINUE THROUGH THE PERIOD...WITH NO HEAT
WAVES OR ABNORMALLY COOL SPELLS IN SIGHT. A COLD FRONT WILL PUSH
ACROSS TUE NIGHT WITH ANOTHER FRONT APPROACHING SAT NIGHT...WITH
SUBSEQUENT HIGHER POPS DURING THOSE PERIODS. IN BETWEEN...THURSDAY
AND FRIDAY LOOK MOSTLY SUNNY TO PERHAPS PARTLY CLOUDY WITH ONLY
MINIMAL CHANCES FOR PRECIP EACH DAY.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
VERY COMPLEX TAFS TODAY GIVEN THE UNSETTLED SURFACE AND UPPER
LEVEL CONDITIONS BRINGING SHOWERS WITH A FEW EMBEDDED STORMS
THROUGH THE PERIOD.
TRIED TO USE AS MUCH PREVAILING SHRA AS POSSIBLE...AND ALSO TRIED
TO PEG THE BEST CHANCES FOR TSRA WITH PEAK HEATING TODAY UTILIZING
THE PROB30 WORDING IN THE TAFS. THIS TIMING HAS A LOWER CONFIDENCE
ATTACHED TO IT.
AFTER THE INITIAL WAVE OF RAIN EXITS THE OHIO VALLEY...EXPECT AN
MVFR STRATUS LAYER TO DEVELOP TOWARDS DAWN. THIS COULD LIMIT
THUNDER CHANCES UNTIL THIS LAYER DISSOLVES...AND WILL MAINLY AFFECT
PKB AND HTS.
LATER TONIGHT...AS THE CEILINGS LOWER AGAIN AFTER THE MAIN BATCH
OF RAIN MOVES INTO THE MOUNTAINS...EXPECT CEILINGS TO LOWER. AS
THIS HAPPENS THE CHANCES FOR VISIBILITIES TO LOWER INCREASE AS
WELL.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z MONDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING AND EXTENT OF TSRA IS IN QUESTION.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE SUN 08/31/14
UTC 1HRLY 08 09 10 11 12 13 14 15 16 17 18 19
EDT 1HRLY 04 05 06 07 08 09 10 11 12 13 14 15
CRW CONSISTENCY M M L L L L M H H H H H
HTS CONSISTENCY M M M L L L M M M H H M
BKW CONSISTENCY M M M M M M M H H H H H
EKN CONSISTENCY L L L L L L M H H H H H
PKB CONSISTENCY M M M L L L L L L H H H
CKB CONSISTENCY M M M L L L L L L M H H
AFTER 06Z MONDAY...
IFR IN DENSE EARLY MORNING VALLEY FOG EARLY NEXT WEEK.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...JMV/26
NEAR TERM...26
SHORT TERM...JMV
LONG TERM...50
AVIATION...26
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
158 AM EDT SUN AUG 31 2014
.SYNOPSIS...
A WEAK COLD FRONT OVER THE GREAT LAKES WILL BECOME STATIONARY ON
SUNDAY JUST NORTH OF LAKE ERIE. AN AREA OF LOW PRESSURE OVER THE
GULF COAST STATES WILL MOVE NORTHEAST UP THE APPALACHIANS
OVERNIGHT AND SUNDAY. A STRONGER COLD FRONT WILL MOVE FROM THE
NORTHERN PLAINS AND CROSS THE AREA ON TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
BAND OF SHOWERS CONTINUE TO MOVE NORTHEAST ACROSS THE EASTERN
PORTIONS OF THE FORECAST AREA IN ASSOCIATION WITH UPPER LEVEL
POSITIVE VORTICITY ADVECTION. MORE ACTIVE ACTIVITY ACROSS SOUTHERN
OHIO SHOULD LIFT NORTHEAST INTO THE REGION OVERNIGHT BUT SHOULD
ALSO WEAKEN TO JUST SHOWERS. FURTHER WEST...A LINE OF SHOWERS AND
THUNDERSTORMS WILL CONTINUE TO ADVANCE EAST WITH THE COLD FRONT.
LATEST HRRR GUIDANCE SUGGESTS LINE WILL WEAKEN BY THE TIME IT
REACHES OUR AREA. THIS SEEMS LOGICAL SINCE THERE IS A LOT OF CIN
OVER THE REGION AT THIS TIME TO OVERCOME.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY NIGHT/...
A WARM...MUGGY AND UNSETTLED AIR MASS WILL LINGER OVER THE AREA
MOST OF THE PERIOD. UNSEASONABLY WARM SURFACE DEW POINTS WILL MAKE
IT FEEL MORE LIKE JULY THAN LABOR DAY WEEKEND. MODELS CONTINUE TO
HAVE DIFFICULTY PIN POINTING PRECIP CHANCES. IT DOES APPEAR THAT
BEST CHANCES FOR PRECIP ON SUNDAY WILL BE ACROSS THE SOUTHEAST
HALF OF THE AREA. FURTHER NORTH WEAK HIGH PRESSURE WILL BRIEFLY
BUILD OVER LAKE ERIE IN THE WAKE OF THE SURFACE LOW MOVING THROUGH
NOW. BY SUNDAY EVENING THE THREAT FOR PRECIP SHOULD BE OVER ALL
AREAS. ANOTHER LOW OVER THE PLAINS WILL LIFT A WARM FRONT BACK
ACROSS THE AREA ON MONDAY. THE MODELS ARE IN A LITTLE BIT BETTER
AGREEMENT WITH THIS SYSTEM. WILL NEED ANOTHER PERIOD OF LIKELY OR
HIGHER WORDING FROM LATE MONDAY TILL A COLD FRONT CROSSES THE
REGION ON TUESDAY. PRECIP CHANCES WILL DIMINISH BY TUESDAY
EVENING. THE FRONTAL PASSAGE WON`T BE STRONG ENOUGH TO BRING A
COMPLETE AIR MASS CHANGE BUT SURFACE DEW POINTS SHOULD DIP INTO THE
LOWER 60S.
SUNDAY WILL BE THE COOLEST DAY OF THE PERIOD WITH THE PRECIP
ACROSS THE AREA. THE REMAINDER OF THE PERIOD WILL BE ABOVE NORMAL
AND HAVE USED A BLEND OF GUIDANCE.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
UPPER RIDGE BUILDS IN FROM THE SOUTH BEHIND EXITING TROUGH ON
WEDNESDAY. WITH INFLUENCE OF THE RIDGE IN WEAK FLOW PATTER MOST
CONVECTION WILL BE SUPPRESSED. CAN`T COMPLETELY RULE OUT TSRA
BUT FOR NOW WILL KEEP A SMALL POP IN THROUGH FRIDAY. THE MODELS ARE
IN FAIRLY STRONG AGREEMENT THAT THE RIDGE WILL LEAD TO H850 TEMPS
18-20C FOR LATE IN THE WEEK. THIS MAKES IT DIFFICULT TO LEAN TOWARDS
THE MUCH COOLER CLIMATOLOGY (UPPER 70S) FOR THU-SAT...SO HAVE
TRENDED CLOSER TO THE MODEL GUIDANCE MID 80S. THE MOISTURE ADVECTION
IS NOT AS FAVORABLE AS IT WAS WITH THE CURRENT WEATHER PATTERN...SO
DESPITE HIGH SFC DEW POINTS THE OVERALL PRECIPITABLE WATER VALUES
FOR THE AIR COLUMN WILL BE LOWER IN THE 1.5" RANGE. THIS WILL AGAIN
SUPPORT A LOWER CHANCE FOR PRECIPITATION. THE TIMING ON THE FRONT
WHICH WILL BRING THE WARM WEATHER TO AN END IS LOOKING MORE LIKE
LATE SATURDAY WHICH SHOULD BRING BETTER CHANCES OF THUNDERSTORMS.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
THE FLOW IS SOUTHWEST AHEAD OF THE COLD FRONT THAT IS WELL NORTH
OF LAKE ERIE. THE FRONT WILL REMAIN WELL NORTH OF THE AREA THROUGH
THE TAF PERIOD. HOWEVER...PLENTY OF MOISTURE IN THIS FLOW WILL CAUSE
MAINLY SHOWERS AT THE TAF SITES THROUGH EARLY AFTERNOON AND THEN A
DECREASE IN SHOWERS. SOME THUNDERSTORMS ARE POSSIBLE. THE
THUNDERSTORMS OVER CENTRAL INDIANA ARE EXPECTED TO DECREASE.
VFR CONDITIONS TO START AND THEN MVFR CEILINGS WILL DEVELOP BY
DAYBREAK ALONG WITH SOME MVFR VISIBILITIES. PLENTY OF LOW LEVEL
MOISTURE SO SOME IFR CEILINGS ARE ALSO POSSIBLE MAINLY BETWEEN
DAYBREAK AND EARLY AFTERNOON. CONFIDENCE IS AROUND 60% THAT SOME
IFR CEILINGS WILL DEVELOP.
OUTLOOK...NON VFR LIKELY AT TIMES IN SHOWERS AND THUNDERSTORMS
THROUGH TUESDAY.
&&
.MARINE...
LOW LEVEL JET WILL STRENGTHEN AS AN AREA OF LOW PRESSURE ADVANCED
TOWARDS LAKE ERIE THIS EVENING. LOOK FOR WINDS AROUND 20KT WITH
GUSTS AROUND 25 KT OVERNIGHT. THE SW DIRECTION WILL KEEP THE LARGEST
WAVES OFFSHORE OR IN CANADIAN WATERS. COULD STILL SEE SOME 4 FOOTERS
IN THE NEAR SHORE. ENERGY WILL SLIDE EAST SUNDAY MORNING AND THOUGH
WINDS ARE STILL SW THE SPEEDS WILL DROP OFF NOTABLY. THE NEXT
FRONTAL BOUNDARY WILL COME THROUGH MONDAY NIGHT AT WHICH TIME THE
WINDS COULD ONCE AGAIN REACH SMALL CRAFT. HIGH PRESSURE WILL BUILD
BACK IN AND WINDS/WAVES WILL REMAIN BELOW HEADLINE CRITERIA THE REST
OF THE FORECAST PERIODS.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR LEZ148-
149.
&&
$$
SYNOPSIS...KOSARIK
NEAR TERM...LOMBARDY
SHORT TERM...KUBINA
LONG TERM...JAMISON
AVIATION...KIELTYKA
MARINE...JAMISON
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1233 AM EDT SUN AUG 31 2014
.SYNOPSIS...
A WEAK COLD FRONT OVER THE GREAT LAKES WILL BECOME STATIONARY ON
SUNDAY JUST NORTH OF LAKE ERIE. AN AREA OF LOW PRESSURE OVER THE
GULF COAST STATES WILL MOVE NORTHEAST UP THE APPALACHIANS
OVERNIGHT AND SUNDAY. A STRONGER COLD FRONT WILL MOVE FROM THE
NORTHERN PLAINS AND CROSS THE AREA ON TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
BAND OF SHOWERS CONTINUE TO MOVE NORTHEAST ACROSS THE EASTERN
PORTIONS OF THE FORECAST AREA IN ASSOCIATION WITH UPPER LEVEL
POSITIVE VORTICITY ADVECTION. MORE ACTIVE ACTIVITY ACROSS SOUTHERN
OHIO SHOULD LIFT NORTHEAST INTO THE REGION OVERNIGHT BUT SHOULD
ALSO WEAKEN TO JUST SHOWERS. FURTHER WEST...A LINE OF SHOWERS AND
THUNDERSTORMS WILL CONTINUE TO ADVANCE EAST WITH THE COLD FRONT.
LATEST HRRR GUIDANCE SUGGESTS LINE WILL WEAKEN BY THE TIME IT
REACHES OUR AREA. THIS SEEMS LOGICAL SINCE THERE IS A LOT OF CIN
OVER THE REGION AT THIS TIME TO OVERCOME.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY NIGHT/...
A WARM...MUGGY AND UNSETTLED AIR MASS WILL LINGER OVER THE AREA
MOST OF THE PERIOD. UNSEASONABLY WARM SURFACE DEW POINTS WILL MAKE
IT FEEL MORE LIKE JULY THAN LABOR DAY WEEKEND. MODELS CONTINUE TO
HAVE DIFFICULTY PIN POINTING PRECIP CHANCES. IT DOES APPEAR THAT
BEST CHANCES FOR PRECIP ON SUNDAY WILL BE ACROSS THE SOUTHEAST
HALF OF THE AREA. FURTHER NORTH WEAK HIGH PRESSURE WILL BRIEFLY
BUILD OVER LAKE ERIE IN THE WAKE OF THE SURFACE LOW MOVING THROUGH
NOW. BY SUNDAY EVENING THE THREAT FOR PRECIP SHOULD BE OVER ALL
AREAS. ANOTHER LOW OVER THE PLAINS WILL LIFT A WARM FRONT BACK
ACROSS THE AREA ON MONDAY. THE MODELS ARE IN A LITTLE BIT BETTER
AGREEMENT WITH THIS SYSTEM. WILL NEED ANOTHER PERIOD OF LIKELY OR
HIGHER WORDING FROM LATE MONDAY TILL A COLD FRONT CROSSES THE
REGION ON TUESDAY. PRECIP CHANCES WILL DIMINISH BY TUESDAY
EVENING. THE FRONTAL PASSAGE WON`T BE STRONG ENOUGH TO BRING A
COMPLETE AIR MASS CHANGE BUT SURFACE DEW POINTS SHOULD DIP INTO THE
LOWER 60S.
SUNDAY WILL BE THE COOLEST DAY OF THE PERIOD WITH THE PRECIP
ACROSS THE AREA. THE REMAINDER OF THE PERIOD WILL BE ABOVE NORMAL
AND HAVE USED A BLEND OF GUIDANCE.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
UPPER RIDGE BUILDS IN FROM THE SOUTH BEHIND EXITING TROUGH ON
WEDNESDAY. WITH INFLUENCE OF THE RIDGE IN WEAK FLOW PATTER MOST
CONVECTION WILL BE SUPPRESSED. CAN`T COMPLETELY RULE OUT TSRA
BUT FOR NOW WILL KEEP A SMALL POP IN THROUGH FRIDAY. THE MODELS ARE
IN FAIRLY STRONG AGREEMENT THAT THE RIDGE WILL LEAD TO H850 TEMPS
18-20C FOR LATE IN THE WEEK. THIS MAKES IT DIFFICULT TO LEAN TOWARDS
THE MUCH COOLER CLIMATOLOGY (UPPER 70S) FOR THU-SAT...SO HAVE
TRENDED CLOSER TO THE MODEL GUIDANCE MID 80S. THE MOISTURE ADVECTION
IS NOT AS FAVORABLE AS IT WAS WITH THE CURRENT WEATHER PATTERN...SO
DESPITE HIGH SFC DEW POINTS THE OVERALL PRECIPITABLE WATER VALUES
FOR THE AIR COLUMN WILL BE LOWER IN THE 1.5" RANGE. THIS WILL AGAIN
SUPPORT A LOWER CHANCE FOR PRECIPITATION. THE TIMING ON THE FRONT
WHICH WILL BRING THE WARM WEATHER TO AN END IS LOOKING MORE LIKE
LATE SATURDAY WHICH SHOULD BRING BETTER CHANCES OF THUNDERSTORMS.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
LOW PRESSURE SYSTEM OVER NORTHERN MICHIGAN WITH COLD FRONT INTO
SOUTHERN PLAINS. SWATH OF SHOWERS WITH A FEW EMBEDDED TSRA NOW
INTO SW OHIO WILL WILL MOVE ACROSS THE SOUTHERN AND EASTERN
LOCATIONS THIS EVENING. MODELS HINT AT ANOTHER WAVE OF PRECIP OVER
THE SOUTHERN AND EASTERN TERMINALS TOMORROW MORNING. FRONT WILL
APPROACH NW OHIO TONIGHT THEN BECOME DIFFUSE...SO COULD SEE SOME
TSRA NW OHIO LATER THIS EVENING. JUST WENT WITH TSVC IN TAFS.
OUTLOOK...NON VFR LIKELY IN SHOWERS AND THUNDERSTORMS THROUGH
TUESDAY AT TIMES.
&&
.MARINE...
LOW LEVEL JET WILL STRENGTHEN AS AN AREA OF LOW PRESSURE ADVANCED
TOWARDS LAKE ERIE THIS EVENING. LOOK FOR WINDS AROUND 20KT WITH
GUSTS AROUND 25 KT OVERNIGHT. THE SW DIRECTION WILL KEEP THE LARGEST
WAVES OFFSHORE OR IN CANADIAN WATERS. COULD STILL SEE SOME 4 FOOTERS
IN THE NEAR SHORE. ENERGY WILL SLIDE EAST SUNDAY MORNING AND THOUGH
WINDS ARE STILL SW THE SPEEDS WILL DROP OFF NOTABLY. THE NEXT
FRONTAL BOUNDARY WILL COME THROUGH MONDAY NIGHT AT WHICH TIME THE
WINDS COULD ONCE AGAIN REACH SMALL CRAFT. HIGH PRESSURE WILL BUILD
BACK IN AND WINDS/WAVES WILL REMAIN BELOW HEADLINE CRITERIA THE REST
OF THE FORECAST PERIODS.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 4 AM EARLY THIS MORNING TO 4 PM EDT
THIS AFTERNOON FOR LEZ148-149.
&&
$$
SYNOPSIS...KOSARIK
NEAR TERM...LOMBARDY
SHORT TERM...KUBINA
LONG TERM...JAMISON
AVIATION...DJB
MARINE...JAMISON
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
556 AM EDT SUN AUG 31 2014
.SYNOPSIS...
A WARM AND HUMID SOUTHWEST FLOW WILL KEEP THE CHANCES FOR RAIN IN
THE FORECAST THROUGH THE LABOR DAY HOLIDAY. A COLD FRONT WILL
BRING A BREAK IN THE HUMIDITY FOR MID WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE RADAR BECOMING MORE ACTIVE WITH SCATTERED SHOWERS AND
THUNDERSTORMS MOVING THROUGH WRN PA...MAKING SLOW PROGRESS TOWARD
MY FCST AREA.
THE HRRR SHOWS THE RAIN CURRENTLY FROM KENTUCKY INTO SOUTHERN OHIO
CONTINUING TO MARCH NORTHEAST THROUGH MORNING WITH MOST OF MY
WESTERN ZONES GETTING WET BY ABOUT 6-7AM...AND MUCH OF THE REST OF
MY FCST AREA COVERED WITH SHOWERS AND THUNDERSTORMS BY MID DAY.
THIS AFTERNOON WE COULD ALSO SEE A SEVERE THREAT DEVELOP FOR MY
SERN ZONES. MODELS ARE COOKING UP A FAIR AMOUNT OF CAPE OVER
EASTERN AREAS HINTING THAT THE THE CLOUDS WILL BE LESS EXTENSIVE
ALLOWING FOR MORE IN THE WAY OF SOLAR HEATING. FORECAST MID LEVEL
LAPSE RATES ARE WEAK BUT SHEAR WILL INCREASE WHICH COULD AID IN
ORGANIZING STORM DEVELOPMENT.
MODELS ALSO PROG A WEAK LOW LEVEL CONVERGENCE ZONE...PERHAPS THE
REMNANTS OF THE OLD WARM FRONT WHERE ENHANCED LOW LEVEL
SHEAR...EHI`S PROGGED 1-3(M^2/S^2) COULD HELP A STORM OR TWO TAKE
ON SOME SPIN. WITH LOW LCLS EXPECTED IN THE VERY TROPICAL
AIRMASS...HAVE TO STAY AWARE OF THE POTENTIAL FOR AN ISOLATED
TORNADO. AS IT STANDS RIGHT NOW...THE SEVERE THREAT WILL BE VERY
DEPENDENT ON GETTING THE SUN TO COME OUT AND FIRST COOK UP THE
CAPES.
WITH AN ANOMALOUSLY STRONG LOW LEVEL JET AND PURE TROPICAL
AIR...ANOTHER THREAT WILL BE LOCALLY HEAVY RAIN IN SOME OF THE
THUNDERSTORMS. IT HAS BEEN DRY SO NO HEADLINES ARE PLANNED...BUT
WILL OPT FOR SOME ENHANCED WORDING IN THE FORECAST AND HWO
PRODUCT.
HIGHS WILL NOT BE TERRIBLY HIGH...IN THE MID 70S TO MID 80S FROM
NW TO SE...BUT DEWPOINTS WELL UP IN THE 60S TO LOWER 70S WILL
BRING ONE OF THE MORE UNCOMFORTABLY HUMID DAYS WE`VE SEEN THIS
SUMMER.
IT`S HARD TO PIN DOWN WHAT WILL OCCUR OVERNIGHT WITH REGARD TO
CONVECTION. ECMWF/NAM/GFS ALL PAINT DIFFERENT SCENARIOS. THE
NAM/SREF REPRESENT THE WETTEST SOLUTIONS WITH SOME SORT OF MESO
LOW TRACKING ACROSS SOUTHERN PA. THE GFS/GEFS ARGUE FOR SMALLER
CHANCES OF RAIN WITH MOST OF THE AREA SEEING WEAK LOW LEVEL
RIDGING DEVELOP IN THE WAKE OF TODAY`S EVENTS. THE ECMWF IS THE
DRIEST OF ALL. RIGHT NOW WE HAVE LIKELY POPS OVER THE SOUTH AND
CHANCE OVER THE NORTH. UNLESS I SEE SOMETHING COMPELLING...WILL
PROBABLY NOT CHANGE IT MUCH GIVEN THE EXPECTATIONS OF LITTLE OR
NO REAL FOCUSING MECHANISM.
ANOTHER WARM MUGGY NIGHT IS IN STORE AS THE AIRMASS WILL REMAIN
VIRTUALLY UNCHANGED.
&&
.SHORT TERM /MONDAY/...
AT THIS TIME I AM HOLDING OUT HOPE OF A DRIER LABOR DAY...BUT
CANNOT DROP THE MENTION OF RAIN ALTOGETHER. SREF/GEFS BOTH SHOW
THE ANOMALOUS PWAT PLUME SLIDING EAST WITH DRYING TAKING PLACE
LOCALLY. SHORT RANGE OPERATIONAL GUIDANCE HINTS AT WEAK SHORTWAVE
RIDGING AND RISING UPPER HEIGHTS...SO I TRENDED POPS DOWN DURING
THE DAY WITH THE THINKING BEING THAT MOST AREAS WILL HAVE A DRY
AFTERNOON AND EVENING FOR THE LAST OF THE TRADITIONAL SUMMER`S
COOKOUTS.
OVERALL IT WILL NOT FEEL SIGNIFICANTLY DRIER HOWEVER AS
TEMPERATURES WILL ONCE AGAIN RISE INTO THE 70S AND 80S WITH
DEWPOINTS REMAINING TROPICAL IN THE 60S AND LOWER 70S.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
STILL PRETTY GOOD AGREEMENT IN A COLD FRONT SWINGING THROUGH THE
STATE LATE TUESDAY. THIS SHOULD PROVIDE THE BEST CHANCE OF RAIN
IN THE EXTENDED BEFORE HIGH PRESSURE BUILDS IN FOR
MIDWEEK...BRINGING A FEW DAYS OF MILD AND DRY WEATHER. THE NEXT
CHANCE FOR RAIN LOOKS LIKE IT WILL NOT BE UNTIL LATER IN THE WEEK
WHEN A MORE HUMID FLOW WILL DEVELOP AROUND THE HIGH MOVING OFF THE
COAST. AT THIS POINT A COLD FRONT LOOKS LIKELY FOR SATURDAY
FOLLOWED BY A COOLER AIRMASS FOR NEXT WEEKEND.
THIS UPCOMING WEEK WILL BE ONE OF THE RARE EXTENDED PERIODS OF
WARMER THAN NORMAL TEMPERATURES WE HAVE SEEN THIS SUMMER. HIGH
TEMPERATURES WILL CLIMB TO ALMOST 90 ACROSS THE SOUTH AND EAST ON
TUESDAY AHEAD OF THE FRONTAL PASSAGE. THEN AN UPPER RIDGE WILL
BUILD OVER THE EASTERN US FOR THE SECOND HALF OF THE
WEEK...KEEPING HIGH TEMPERATURES AT OR SLIGHTLY ABOVE SEASONAL
NORMALS FOR EARLY SEPTEMBER.
&&
.AVIATION /10Z SUNDAY THROUGH THURSDAY/...
CIGS AT MANY SPOTS SUCH AS UNV AND AOO GOING BETWEEN SCT015
AMD BKN015 FOR EXAMPLE...AS BEEN THE CASE SINCE YESTERDAY.
ANYWAY...THE MAIN ISSUE NOW IS THE LARGE AREA OF SHOWERS
AND THUNDERSTORMS JUST STARTING TO MOVE INTO OUR AREA FROM
PIT.
BEEN UPDATING FCST AS NEEDED.
OUTLOOK...
MON...AM FOG POSS...ESP W MTNS. ISOLD PM TSRA IMPACTS
POSS.
TUE...SCT PM TSRA IMPACTS POSS.
WED...PATCHY AM FOG POSS.
THU...PATCHY AM FOG POSS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...LA CORTE
AVIATION...MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
444 AM EDT SUN AUG 31 2014
.SYNOPSIS...
A WARM AND HUMID SOUTHWEST FLOW WILL KEEP THE CHANCES FOR RAIN IN
THE FORECAST THROUGH THE LABOR DAY HOLIDAY. A COLD FRONT WILL
BRING A BREAK IN THE HUMIDITY FOR MID WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE RADAR BECOMING MORE ACTIVE WITH SCATTERED SHOWERS AND
THUNDERSTORMS MOVING THROUGH WRN PA...MAKING SLOW PROGRESS TOWARD
MY FCST AREA.
THE HRRR SHOWS THE RAIN CURRENTLY FROM KENTUCKY INTO SOUTHERN OHIO
CONTINUING TO MARCH NORTHEAST THROUGH MORNING WITH MOST OF MY
WESTERN ZONES GETTING WET BY ABOUT 6-7AM...AND MUCH OF THE REST OF
MY FCST AREA COVERED WITH SHOWERS AND THUNDERSTORMS BY MID DAY.
THIS AFTERNOON WE COULD ALSO SEE A SEVERE THREAT DEVELOP FOR MY
SERN ZONES. MODELS ARE COOKING UP A FAIR AMOUNT OF CAPE OVER
EASTERN AREAS HINTING THAT THE THE CLOUDS WILL BE LESS EXTENSIVE
ALLOWING FOR MORE IN THE WAY OF SOLAR HEATING. FORECAST MID LEVEL
LAPSE RATES ARE WEAK BUT SHEAR WILL INCREASE WHICH COULD AID IN
ORGANIZING STORM DEVELOPMENT.
MODELS ALSO PROG A WEAK LOW LEVEL CONVERGENCE ZONE...PERHAPS THE
REMNANTS OF THE OLD WARM FRONT WHERE ENHANCED LOW LEVEL
SHEAR...EHI`S PROGGED 1-3(M^2/S^2) COULD HELP A STORM OR TWO TAKE
ON SOME SPIN. WITH LOW LCLS EXPECTED IN THE VERY TROPICAL
AIRMASS...HAVE TO STAY AWARE OF THE POTENTIAL FOR AN ISOLATED
TORNADO. AS IT STANDS RIGHT NOW...THE SEVERE THREAT WILL BE VERY
DEPENDENT ON GETTING THE SUN TO COME OUT AND FIRST COOK UP THE
CAPES.
WITH AN ANOMALOUSLY STRONG LOW LEVEL JET AND PURE TROPICAL
AIR...ANOTHER THREAT WILL BE LOCALLY HEAVY RAIN IN SOME OF THE
THUNDERSTORMS. IT HAS BEEN DRY SO NO HEADLINES ARE PLANNED...BUT
WILL OPT FOR SOME ENHANCED WORDING IN THE FORECAST AND HWO
PRODUCT.
HIGHS WILL NOT BE TERRIBLY HIGH...IN THE MID 70S TO MID 80S FROM
NW TO SE...BUT DEWPOINTS WELL UP IN THE 60S TO LOWER 70S WILL
BRING ONE OF THE MORE UNCOMFORTABLY HUMID DAYS WE`VE SEEN THIS
SUMMER.
IT`S HARD TO PIN DOWN WHAT WILL OCCUR OVERNIGHT WITH REGARD TO
CONVECTION. ECMWF/NAM/GFS ALL PAINT DIFFERENT SCENARIOS. THE
NAM/SREF REPRESENT THE WETTEST SOLUTIONS WITH SOME SORT OF MESO
LOW TRACKING ACROSS SOUTHERN PA. THE GFS/GEFS ARGUE FOR SMALLER
CHANCES OF RAIN WITH MOST OF THE AREA SEEING WEAK LOW LEVEL
RIDGING DEVELOP IN THE WAKE OF TODAY`S EVENTS. THE ECMWF IS THE
DRIEST OF ALL. RIGHT NOW WE HAVE LIKELY POPS OVER THE SOUTH AND
CHANCE OVER THE NORTH. UNLESS I SEE SOMETHING COMPELLING...WILL
PROBABLY NOT CHANGE IT MUCH GIVEN THE EXPECTATIONS OF LITTLE OR NO
REAL FOCUSING MECHANISM.
ANOTHER WARM MUGGY NIGHT IS IN STORE AS THE AIRMASS WILL REMAIN
VIRTUALLY UNCHANGED.
&&
.SHORT TERM /MONDAY/...
AT THIS TIME I AM HOLDING OUT HOPE OF A DRIER LABOR DAY...BUT
CANNOT DROP THE MENTION OF RAIN ALTOGETHER. SREF/GEFS BOTH SHOW
THE ANOMALOUS PWAT PLUME SLIDING EAST WITH DRYING TAKING PLACE
LOCALLY. SHORT RANGE OPERATIONAL GUIDANCE HINTS AT WEAK SHORTWAVE
RIDGING AND RISING UPPER HEIGHTS...SO I TRENDED POPS DOWN DURING
THE DAY WITH THE THINKING BEING THAT MOST AREAS WILL HAVE A DRY
AFTERNOON AND EVENING FOR THE LAST OF THE TRADITIONAL SUMMER`S
COOKOUTS.
OVERALL IT WILL NOT FEEL SIGNIFICANTLY DRIER HOWEVER AS
TEMPERATURES WILL ONCE AGAIN RISE INTO THE 70S AND 80S WITH
DEWPOINTS REMAINING TROPICAL IN THE 60S AND LOWER 70S.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
STILL PRETTY GOOD AGREEMENT IN A COLD FRONT SWINGING THROUGH THE
STATE LATE TUESDAY. THIS SHOULD PROVIDE THE BEST CHANCE OF RAIN IN
THE EXTENDED BEFORE HIGH PRESSURE BUILDS IN FOR
MIDWEEK...BRINGING A FEW DAYS OF MILD AND DRY WEATHER. THE NEXT
CHANCE FOR RAIN LOOKS LIKE IT WILL NOT BE UNTIL LATER IN THE WEEK
WHEN A MORE HUMID FLOW WILL DEVELOP AROUND THE HIGH MOVING OFF THE
COAST. AT THIS POINT A COLD FRONT LOOKS LIKELY FOR SATURDAY
FOLLOWED BY A COOLER AIRMASS FOR NEXT WEEKEND.
THIS UPCOMING WEEK WILL BE ONE OF THE RARE EXTENDED PERIODS OF
WARMER THAN NORMAL TEMPERATURES WE HAVE SEEN THIS SUMMER. HIGH
TEMPERATURES WILL CLIMB TO ALMOST 90 ACROSS THE SOUTH AND EAST ON
TUESDAY AHEAD OF THE FRONTAL PASSAGE. THEN AN UPPER RIDGE WILL
BUILD OVER THE EASTERN US FOR THE SECOND HALF OF THE
WEEK...KEEPING HIGH TEMPERATURES AT OR SLIGHTLY ABOVE SEASONAL
NORMALS FOR EARLY SEPTEMBER.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
THERE WERE A FEW STORMS ACROSS THE NW AT MIDNIGHT. MOST OF THESE
NE OF OUR AREA...UP IN WESTERN NY.
MAIN ISSUE OVERNIGHT WILL BE A WIDE RANGE OF CONDITIONS. LOW
CIGS WILL BE IN SOME SPOTS.
06Z TAFS SENT.
EARLIER DISCUSSION BELOW.
LATE EVENING SATL IMAGERY SHOWS STRATUS COVERING THE EASTERN HALF
OF THE STATE...THE RESULT OF MOIST SERLY FLOW OFF THE ATLANTIC
OCEAN. FURTHER WEST...WIDESPREAD VFR NOTED ACROSS THE WESTERN HALF
OF THE STATE.
ALL MDL DATA POINTS TOWARD DETERIORATING FLYING CONDS
OVERNIGHT. PLUME OF HIGH MOISTURE IS IN PLACE OVR CENTRAL PA AND
AS LOW LVLS COOL...EXPECT LOWERING STRATUS OVR MOST OF CENTRAL PA.
THE WORST CONDS IN THE FORM OF IFR CIGS ARE LIKELY TO BE AT KBFD
LATE TONIGHT...WHERE SW FLOW ASCENDS THE HIGHER TERRAIN OF NW PA.
MOS GUIDANCE INDICATING A DIP TO IFR CIGS ACROSS MUCH OF CENTRAL
PA EARLY SUN AM. HOWEVER...BASED ON LATEST SREF OUTPUT AND
EXPECTED SOUTHERLY FLOW RATHER THAN SERLY...BELIEVE MVFR CIGS ARE
MORE LIKELY FROM KAOO AND KUNV EASTWARD. THE BEST FLYING CONDS ARE
LIKELY TO BE AT KJST...WHERE SOUTH WIND DOWNSLOPING THE HIGHER
TERRAIN OF THE CENTRAL APPALACHIANS MAY KEEP CONDS VFR THERE
OVERNIGHT.
A TROUGH OF LOW PRESSURE APPROACHING FROM THE GRT LKS WILL SPREAD
A BAND OF SHRA INTO NW PA SUNDAY MORNING. SCT SHRA/TSRA WILL
DEVELOP AHEAD OF THIS FEATURE OVR THE REST OF CENTRAL PA BY SUN
AFTN. LOCALIZED VSBY REDUCTIONS ARE POSSIBLE IN ANY OF THESE
SHOWERS. HOWEVER...THE BIGGEST AVIATION CONCERN SUNDAY WILL BE THE
POSSIBLE LOW CIGS IN THE MORNING...ESP KBFD. PREDOMINANTLY VFR
CONDS ARE LIKELY BY SUNDAY AFTN.
OUTLOOK...
MON...AM FOG POSS...ESP W MTNS. ISOLD PM TSRA IMPACTS POSS.
TUE...SCT PM TSRA IMPACTS POSS.
WED...PATCHY AM FOG POSS.
THU...PATCHY AM FOG POSS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...LA CORTE
AVIATION...FITZGERALD/MARTIN
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
150 AM EDT SUN AUG 31 2014
.SYNOPSIS...
A BERMUDA HIGH WILL DEVELOP AND LINGER INTO EARLY NEXT WEEK...
RESULTING IN TYPICAL SUMMERTIME HEAT AND SCATTERED AFTERNOON
THUNDERSTORMS EACH DAY.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 145 AM EDT SUNDAY...BAND OF CONVECTION CONTINUES TO SLOWLY
PUSH EAST ACROSS NORTHEAST GA AND SOUTHWEST NC THIS MORNING.
LIGHT/MODERATE PRECIPIATION RATES HAVE BEEN OBSERVED WITH A FEW
LOCATIONS RECEIVING NEARLY AN INCH PER HOUR. AS THIS CONVECTION
CONTINUES TO MOVE EAST INTO THE WESTERN UPSTATE OF SC...EXPECTING A
WEAKENING TREND TO PREVAIL WITH DECREASING RAIN RATES LIKELY. THAT
SAID...DECIDED TO INCREASE POPS SUBSTANTIALLY FOR THESE AFFECTED
ZONES OVER THE NEXT FEW HOURS WITH POPS TRENDING DOWN NEAR
DAYBREAK. ALSO MADE QPF ADJUSTMENTS TO ACCOUNT FOR ABOVE MENTIONED
RAIN RATES WHICH DID NOT REVEAL ANY FLOODING CONCERNS AS FORWARD
PROPAGATION REMAINS SUFFICIENT. OTHERWISE...TWEAKED TEMPERATURES
AND DEWPOINTS TO REFLECT LATEST OBSERVATIONAL TRENDS WITH NO OTHER
CHANGES MADE.
PREVIOUS DISCUSSIONS...
EVENING UPDATE...MADE A NOTABLE CHANGE TO THE POP/WX/QPF GRIDS
OVERNIGHT. THE LAST FEW RUNS OF THE HRRR HAVE BEEN CONSISTENT AND
THE LATEST OP MODELS HAVE CAUGHT ONTO THE IDEA OF A LINE OF
-SHRA/TSRA ORGANIZING ACROSS THE SW/RN ZONES ARND 06Z THEN PUSHING
NE THRU 12Z BEFORE DISSIPATING. WONT ANTICIPATE STRONG WX WITH THIS
LINE AS IT MOVES UNDERNEATH STRONG RIDGING ALOFT AND INSTABILITY
WILL BE WEAK THROUGH A DEEP LAYER. OTHERWISE...A FG THREAT ACROSS
THE MTNS AND NC FTHILLS WILL BE CURTAILED WITH CONTINUED BKN/OVC
CLOUD COVER...YET PATCHY VSBYS IN THE ONE MILE OR LESS RANGE COULD
DEVELOP ACROSS THE NC MTN VALLEYS BEFORE DAYBREAK AS CLOUDS THIN
FROM THE SW AFT 09Z. MIN TEMPS WERE BUMPED UP A DEGREE OR TWO MOST
LOCALE BASED ON LATEST TRENDS AND ANTICIPATED SLOW COOLING
RATES.
AS OF 215 PM...LATEST CAM`S SHOWING A LITTLE MORE CONVECTIVE
RESPONSE THIS AFTERNOON SO HAVE NUDGED THE POPS HIGHER OVER THE
WESTERN UPSTATE AND THE MOUNTAINS. IT STILL LOOKS LIKE CONVECTIVE
COVERAGE WILL INCREASE AS THE AFTERNOON PROGRESSES OVER NE GA AND
THE SW MOUNTAINS...WITH COVERAGE THEN SPREADING NE INTO THE CENTRAL
MOUNTAINS/NORTHERN MOUNTAINS DURING THE EVENING HOURS AS A WEAK
SHORT WAVE MOVES THROUGH TN. CAN`T RULE OUT SOME SHOWERS/STORMS
AFFECTING THE ADJACENT FOOTHILLS/PIEDMONT DURING THE EVENING SO HAVE
BUMPED POPS UPWARD THERE PER LATEST CAMS. HAVE DISCOUNTED THE
SPURIOUS DEEP CONVECTION AND HEAVY QPF THAT THE NAM DEVELOPS IN THE
NC PIEDMONT OVERNIGHT. DO NOT SEE THE TRIGGERING MECHANISM FOR SUCH
A RESPONSE AND THERE IS NO SUPPORT FROM ANY OTHER MODEL.
IN REGARD TO THE BIG PICTURE...THE UPPER HIGH WILL BE GRADUALLY
SUPPRESSED TO THE SE AS A SERIES OF SHORT WAVES MOVE THROUGH THE TN
VALLEY INTO THE MID-ATLANTIC STATES. THE FIRST OF THESE SHORT WAVES
WILL MOVE BY THIS EVENING AND THEN ANOTHER ON SUNDAY. AS THE FIRST
WAVE MOVES BY TO THE WEST TONIGHT...SCT SHOWERS AND STORMS WILL
OCCUR MAINLY OVER THE MOUNTAINS...POSSIBLY CONTINUING INTO THE EARLY
MORNING HOURS OF SUNDAY. WITH MOIST PROFILES AND WEAK WIND FIELDS...
SEVERE STORMS ARE NOT EXPECTED. HOWEVER...SOME LOCALLY HEAVY IS
POSSIBLE.
ON SUNDAY...SCT SHOWERS AND STORMS ARE EXPECTED TO DEVELOP AGAIN AS
ANOTHER SHORT WAVE MOVES BY TO THE WEST COINCIDING WITH MAX HEATING.
THE MODELS HAVE BEEN TRENDING AWAY FROM SHOWING MUCH QPF RESPONSE
OUTSIDE THE MOUNTAINS ON SUNDAY. HENCE...HAVE DIALED BACK POPS TO
THE SLIGHT CHANCE/CHANCE RANGE OVER THE PIEDMONT. THE BEST COVERAGE
SHOULD BE ALONG THE SPINE OF THE MOUNTAINS WHERE NUMEROUS STORMS MAY
OCCUR.
USED OUR CONSALL BLEND TO POPULATE MOST FIELDS. TEMPS WILL CONTINUE
ABOVE CLIMO. MAX TEMPS ON SUNDAY WILL BE CLOSE TO TODAY`S
NUMBERS...THOUGH PERHAPS A COUPLE DEGREES LESS WARM IN THE MOUNTAINS
DUE TO MORE CONVECTIVE COVERAGE.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY/...
AS OF 200 PM SATURDAY...FAIRLY STANDARD LATE SUMMER WEATHER IS
EXPECTED THROUGH THE SHORT TERM...AS SUBTROPICAL/BERMUDA HIGH
PRESSURE REMAINS AS THE DOMINANT SYNOPTIC SCALE FEATURE ACROSS THE
SOUTHEAST. THIS SHOULD GENERALLY SUPPORT WARM AND HUMID CONDITIONS
THROUGH THE PERIOD...WITH CHANCES FOR DIURNAL CONVECTION GENERALLY
EXPECTED TO BE NEAR TO SLIGHTLY ABOVE CLIMO (30 PERCENT MTNS/20
PERCENT ACROSS THE LOWER TERRAIN) MON AND TUE AFTERNOONS. CONVECTIVE
CHANCES MAY INCREASE SLIGHTLY ACROSS OUR WESTERN AREAS BY TUE
EVENING...AS DEEP LAYER MOISTURE INCREASES AHEAD OF A WEAK FRONTAL
ZONE. TEMPERATURES ARE EXPECTED TO REMAIN ABOUT A CATEGORY ABOVE
NORMAL THROUGH THE PERIOD.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 230 PM EDT SATURDAY...THE LATEST GLOBAL MODELS INDICATE THAT
H5 HEIGHTS WILL CONTINUE TO RISE OVER THE FORECAST AREA TUE NIGHT
INTO FRI AS A BROAD UPPER RIDGING AMPLIFIES ACROSS THE SOUTHEAST AND
GULF STATES. BY SAT...WEAK UPPER NWLY FLOW WILL SET UP AS THE CENTER
OF UPPER ANTICYCLONE RETROGRADES TOWARD THE WESTERN CONUS. AT THE
SURFACE...HIGH PRESSURE WILL WEAKEN AND SLIDE SOUTH OF THE AREA TUE
NIGHT AS A WEAK COLD FRONT APPROACHES FROM THE NW. THE FRONT WILL
PUSH THRU THE AREA ON WED AND BECOMES STATIONARY JUST TO OUR SOUTH
BY THU. A BERMUDA HIGH WILL THEN BUILD BACK IN FROM THE SE BY FRI
AND REMAIN IN PLACE THRU DAY 7. AS FOR OUR SENSIBLE WEATHER...HAVE
MENTIONED 30/40 POPS WED/THU DUE TO INCREASING MOISTURE AND BUOYANCY
ALONG AND AHEAD OF THE FRONT. FRI/SAT...DIURNAL BUOYANCY AND
MOISTURE UNDER THE INFLUENCE OF BERMUDA HIGH WILL BE SUPPORTIVE OF
SCATTERED AFTERNOON SHOWERS AND THUNDERSTORMS ON EACH
DAY...MAINTAINING POPS IN THE 30/40 RANGE. TEMPERATURES WILL STAY
AROUND 2-5 DEGREES ABOVE NORMAL WED/THU BEFORE COOLING TO NEAR
NORMAL BY FRI.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AT KCLT...VFR CONDITIONS WILL PREVAIL INITIALLY AHEAD OF POSSIBLE
VISB REDUCTIONS NEAR DAYBREAK. INITIALIZED TAF VFR WITH 07KT
SOUTHERLY WINDS UNDER SCT LOW VFR STRATOCU. INTRODUCED 2HR TEMPO AT
11Z TO ACCOUNT FOR DECOUPLING PBL AND POTENTIAL MVFR LEVEL FOG
RESTRICTIONS. BY 13Z CONDITIONS WILL IMPROVE UNDER BKN/OVC LOW
LEVEL STRATUS LASTING THROUGH MUCH OF THE MORNING BEFORE LOW LEVEL
MOISTURE MIXES OUT. BY MIDDAY...SKIES WILL FEATURE SCT MID/HIGH
LEVEL CLOUDS WITH INCREASING SOUTHERLY WINDS FOR THE REMAINDER OF
THE PERIOD. AS FOR WX...CURRENT RADAR TRENDS AND LATEST CAM
GUIDANCE INDICATE BAND OF CONVECTION ACROSS NORTHEAST GA WILL NOT
SURVIVE THE TRIP EAST INTO THE NC PIEDMONT...THEREFORE NO WX MENTION
FOR THIS FEATURE. HOWEVER...AS THE PROFILE HEATS DURING THE
AFTERNOON HOURS ON SUNDAY CANNOT RULE OUT SHRA/TSRA LATE IN THE DAY
THEREFORE KEPT PREVIOUS PROB30 FOR SUCH.
ELSEWHERE...A MIXTURE OF VFR/MVFR AND POSSIBLE IFR CONDITIONS WILL
BE POSSIBLE THROUGH THE EVENING AT ALL SITES. ABOVE MENTIONED BAND
OF CONVECTION WILL SPREAD EAST AFFECTING THE SC SITES ALONG WITH
KAVL THROUGH THE OVERNIGHT. THEREFORE EACH TAF LOCATION FEATURES
PREVAILING VCTS LEADING UP TO ARRIVAL WITH A TEMPO FOR TSRA AND IFR
CIGS/VISB DURING PASSAGE. CONDITIONS WILL SLOWLY IMPROVE AFTER
DAYBREAK AT ALL SITES AS ABOVE MENTIONED SHRA/TSRA ERODES ALONG WITH
INCREASING CLOUD BASES. VFR WILL PREVAIL LATE IN THE PERIOD WITH
THE EXCEPTION OF PROB30 MENTION AT KAVL AND KHKY TO ACCOUNT FOR
AFTERNOON CONVECTION. WINDS THROUGH THE PERIOD WILL REMAIN
SOUTHERLY WITH FLOW INCREASING INTO SUNDAY AFTERNOON.
OUTLOOK...GENERALLY VFR CONDITIONS ARE EXPECTED THROUGH EARLY NEXT
WEEK WITH THE EXCEPTION FOR RESTRICTIONS IN THE EARLY MORNING DUE TO
LOW CLOUDS AND FOG...PRIMARILY IN THE MOUNTAIN VALLEYS. DIURNAL
CONVECTION IS EXPECTED EACH AFTERNOON WITH THE MOST COVERAGE OVER
THE MOUNTAINS.
CONFIDENCE TABLE...
05-11Z 11-17Z 17-23Z 23-05Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP MED 72% MED 66% HIGH 100% HIGH 100%
KAVL HIGH 84% HIGH 86% HIGH 100% HIGH 100%
KHKY MED 79% HIGH 92% HIGH 100% HIGH 100%
KGMU HIGH 81% LOW 58% HIGH 100% HIGH 100%
KAND HIGH 81% MED 68% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JOH
NEAR TERM...CDG/LG/SBK
SHORT TERM...JDL
LONG TERM...JOH
AVIATION...CDG
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
439 AM CDT SUN AUG 31 2014
.DISCUSSION...
ALTHOUGH THERE WAS PLENTY OF TROPICAL MOISTURE AND LIFT FROM AN
UPPER LEVEL TROUGH AXIS...THE MAJORITY OF CONVECTION FORMED IN THE
GULF OF MEXICO AND MOVED INTO E TX AND SW LA. LAKE CHARLES ENDED
UP WITH 7.87 INCHES OF RAIN FOR YESTERDAY. THERE IS A SIMILAR
ENVIRONMENT IN PLACE TODAY WITH TROPICAL MOISTURE STILL OVER MUCH
OF SE TX AND UPPER TX COAST. THE TROUGH AXIS IS SLOWLY WEAKENING
BUT STILL COULD BE A FOCUS FOR CONVECTIVE ACTIVITY. BOTH 00Z
LCH/CRP SOUNDINGS SHOWED 2.2 INCHES OF PRECIP WATER AND GOES
SOUNDER DATA ALSO DEPICTS A SWATH OF TROPICAL MOISTURE STRETCHING
SW TO NE ACROSS THE TX COAST. BASED ON WATER VAPOR IMAGERY TROUGH
AXIS SHOULD BE MOVING OUT OF THE AREA AS UPSTREAM SHORT WAVE
TROUGH MOVES ACROSS THE ROCKIES AND INTO THE PLAINS LATER
TODAY/TONIGHT. THIS SHOULD ALSO HELP ADVECT TROPICAL MOISTURE OVER
THE REGION THIS MORNING AND AFTERNOON. HI RES MODELS WRF-
ARW/RAP/HRRR DEVELOP CONVECTION ALONG THE UPPER TX COAST AND MOVE
IT INTO THE COASTAL COUNTIES AROUND 12Z THIS MORNING. RADAR
ALREADY SHOWING SOME SHOWER ACTIVITY FROM MATAGORDA BAY AND
OFFSHORE. THIS SEEMS TO BE MATCHING THE TRENDS IN THE SHORT RANGE
HI RES MODELS. THE NAM/GFS/ECMWF ALSO SUPPORT THE IDEA OF A SWATH
OF PRECIP EMBEDDED WITHIN MAIN TROPICAL MOISTURE AXIS. DECIDED TO
KEEP MENTION OF 60 POPS. AGAIN WITH THIS MUCH MOISTURE STRONGER
STORMS WILL BE CAPABLE OF 1-2 INCHES OF RAIN AN HOUR. ACCUMULATED
PRECIP TOTALS FROM 06Z HRRR SHOW SWATH OF 2-4 INCHES OF RAIN BY
21Z THIS AFTERNOON SO ISOLATED HIGHER AMOUNTS OF RAIN WILL BE
POSSIBLE. MODELS DO INDICATE RAINFALL COMING TO AN END LATE
AFTERNOON AND EVENING SO DECREASED RAIN CHANCES FOR THE AFTERNOON.
OVERALL MOISTURE TRENDS IN NAM/GFS KEEP NEARLY 2 INCHES OF PRECIP
WATER OVER THE TX COAST THROUGH THE MIDDLE OF THE WEEK. A TROPICAL
WAVE IN THE NW CARIBBEAN SHOULD BE MOVING ACROSS THE YUCATAN TODAY
AND TOMORROW. NHC GIVES THIS WAVE A 50 PERCENT CHANCE OF BECOMING
A TROPICAL CYCLONE OVER NEXT 5 DAYS. ITS BEST CHANCE TO DO SO PER
LATEST MODEL GUIDANCE WILL NOT BE UNTIL IT EMERGES IN THE GULF.
EVEN THEN ONLY THE NAM REALLY DEVELOPS THE SYSTEM INTO A CLOSED
CIRCULATION. THE GFS/ECMWF KEEP IT AS AN OPEN WAVE WHICH HAS BEEN
WAY MORE CONSISTENT THAN THE NAM. OVERALL IMPACT TO TX WILL BE TO
KEEP A FETCH OF DEEP MOISTURE OFF THE GULF IN PLACE. THIS SHOULD
ALLOW FOR DAILY RAIN CHANCES FOR THE NEXT WEEK WITH DAY TIME
HEATING DRIVING CONVECTIVE TRENDS. COVERAGE IN CONVECTION WILL BE
THE REAL ISSUE AS GLOBAL MODELS ESTABLISH A BROAD ELONGATED UPPER
LEVEL RIDGE OVER MUCH OF THE SOUTHERN U.S. THE STRENGTH OF THE
RIDGE IS ALSO A QUESTION SO DIFFICULT TO GAGE HOW MUCH SUBSIDENCE
WILL BE OCCURRING DUE TO THE RIDGE. WITH THESE FACTORS IN MIND THE
FORECAST WILL KEEP AT LEAST SOME MENTION OF THUNDERSTORMS EACH
DAY. IT LOOKS LIKE THE HIGHER RAIN CHANCES WILL BE TUE/WED AS THIS
IS WHEN TROPICAL MOISTURE FROM THE TROPICAL WAVE MAY IMPACT THE
AREA. FORECAST WILL GO WITH 30/40 POPS FOR THESE DAYS WITH 20 POPS
FOR THE REST OF THE WEEK.
TEMPERATURES FOR THE WEEK WILL BE ABOVE NORMAL BUT STILL THE MORE
TYPICAL SUMMER TIME TEMPERATURES. MIN TEMPS IN THE MID/UPPER 70S
WILL BE EXPECTED WITH MAX TEMPS IN THE LOW/MID 90S. TEMPS WILL BE
GREATLY INFLUENCED BY CONVECTION AND RESULTING CLOUD COVER. AS IT
STANDS...WITH 100F NOT EXPECTED FOR A HIGH TEMPERATURE AT KCLL OR
KIAH TODAY...THE STREAK OF NOT REACHING 100F FOR A HIGH
TEMPERATURE CONTINUES INTO SEPTEMBER. HOPEFULLY IT STAYS THAT WAY
FOR THE REST OF THE YEAR.
39
&&
.MARINE...
SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP THIS
MORNING ACROSS THE COASTAL WATERS AS DEEP TROPICAL MOISTURE MOVES
BACK INTO THE REGION. EXPECT ONSHORE FLOW TO PERSIST THROUGH MUCH
OF THE UPCOMING WEEK. WIND SPEEDS WILL INCREASE LATE MONDAY NIGHT
INTO TUESDAY AND CAUTION FLAGS MAY BE NEEDED FOR THE COASTAL
WATERS. 38
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 94 76 95 76 95 / 20 10 20 10 20
HOUSTON (IAH) 91 77 93 77 93 / 40 10 30 20 30
GALVESTON (GLS) 88 81 89 82 89 / 60 10 30 30 40
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...39
AVIATION/MARINE...38
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
405 AM EDT SUN AUG 31 2014
.SYNOPSIS...
THE REGION WILL STAY BETWEEN A LARGE HIGH PRESSURE SYSTEM OVER
THE SOUTHEAST UNITED STATES AND WESTERN ATLANTIC AND A COMPLEX LOW
PRESSURE SYSTEM CROSSING THE GREAT LAKES. A COLD FRONT FINALLY
ARRIVES FROM THE NORTH BY THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 400 AM EDT SUNDAY...
ELONGATED BAROCLINIC ZONE IS SUPPORTED BY AN UPPER JET AND AXIS OF
VORTICITY THAT EXTENDS FROM THE LOWER MISSISSIPPI VALLEY TO NEW
ENGLAND. UPPER RIDGE REMAINS PARKED OVER THE NORTH CAROLINA COAST.
BAND OF DEEPER MOISTURE SHOWN ON WATER VAPOR AND TOTAL PRECIPITABLE
WATER IMAGES WILL MAKE ONLY SLOW PROGRESS EAST INTO THE COUNTY
WARNING AREA BY MONDAY MORNING.
MODELS BRING CLUSTER OF SHOWERS AND THUNDERSTORMS OVER KENTUCKY AND
TENNESSEE ACROSS MUCH OF THE FORECAST AREA THIS MORNING. NOT SURE
HOW FAR EAST THIS PRECIPITATION WILL GET. 06Z HRRR HAD REASONABLE
TIMING MOVING THE EASTERN EDGE INTO THE FORECAST AREA THROUGH 8AM
SO WILL BE FOLLOWING THAT ALONG WITH RADAR TRENDS.
LARGER BAND OF SHOWERS WILL PIVOT ENOUGH TO REACH SOUTHEAST WEST
VIRGINIA TONIGHT...SIMILAR TO ORIENTATION OF WPC QPF FORECAST AND
THE 00Z GFS...SLIGHTLY FARTHER SOUTH THAN THE 00Z NAM.
4KM NAM AND HRRR DEVELOP THUNDERSTORMS ALONG THE BLUE RIDGE THIS
AFTERNOON...CLOSE TO THE EDGE OF THE THICKER CLOUD COVER. EXPECT
THE COVERAGE OF THUNDERSTORMS IN THE EAST TO DIMINISH AFTER SUNSET.
CLOUDS WILL LIMIT HEATING AND INSTABILITY TODAY. STAYED CLOSER TO
BIAS CORRECTED MAV GUIDANCE FOR MAXIMUM TEMPERATURES. HUMID AIR MASS
AND VERY MILD DEW POINTS WILL RESULT IN LITTLE COOLING TONIGHT. USED
WARMER MET GUIDANCE FOR OVERNIGHT LOWS.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
AS OF 300 AM EDT SUNDAY...
PROGRESSIVE NORTHERN STREAM FLOW WILL PRODUCE TROUGHING ACROSS THE
NORTHEAST BY MONDAY MORNING. SEVERAL SHORTWAVES TRAVERSE ACROSS THE
MID ATLANTIC REGION. THESE UPPER DISTURBANCES WILL SHAPE THE TIMING
OF CONVECTION.
AN UPPER DISTURBANCE WILL SHIFT ACROSS THE GREAT LAKES FROM THE OHIO
RIVER VALLEY MONDAY MORNING...ENHANCING THE CHANCES OF SHOWERS IN
THE WEST-NORTHWEST. THE SUBTROPICAL BERMUDA HIGH PRESSURE WILL
REMAIN IN PLACE. A VERY MOIST SOUTHWEST FLOW WILL CONTINUE LABOR
DAY. HIGH TEMPERATURES MONDAY WILL RANGE FROM THE UPPER 70S IN THE
MOUNTAINS TO THE LOWER 90S IN THE PIEDMONT.
SCATTERED SHOWERS AND THUNDERSTORMS REDEVELOP MONDAY AFTERNOON WITH
SOLAR HEATING. SOME OF THE THUNDERSTORMS MAY CONTAIN LOCALLY HEAVY
RAINS. RAINFALL WILL DIMINISH QUICKLY AS THE SUN SETS AND SHOULD SEE
DRY...ALBEIT WARM AND MUGGY...CONDITIONS PERSIST THROUGH MONDAY
NIGHT. LOW TEMPERATURES MONDAY NIGHT WILL VARY FROM THE LOWER 60S IN
THE WEST TO THE AROUND 70 IN THE EAST.
DEEP LAYER MOISTURE INCREASES TUESDAY AS ANOTHER LOW PRESSURE SYSTEM
MOVING ACROSS EASTERN CANADA WILL DRAG A COLD FRONT SOUTH OF THE
GREAT LAKES. BETTER CHANCES FOR CONVECTION WILL BE FOUND ACROSS THE
HIGHER TERRAIN...WHERE STRONGER UPPER LEVEL SUPPORT WILL BE LOCATED.
HIGHS TUESDAY WILL CLIMB INTO THE LOWER 80S IN THE MOUNTAINS TO THE
LOWER 90S IN THE PIEDMONT.
MODEL TREND HAVE BEEN SLOWING THE TIMING OF THE FRONT AND EXPECT THE
COLD FRONT WILL STALL FURTHER NORTH TUESDAY NIGHT DUE TO THE UPPER
LEVEL RIDGING IN PLACE ACROSS THE SOUTHEAST STATES. LOWS WILL FALL
INTO THE MID 60S TO THE LOW 70S TUESDAY NIGHT.
KEPT THE HIGHEST POPS ACROSS THE SOUTH WEDNESDAY ALONG THE STALLED
FRONTAL BOUNDARY. WHILE...HIGH PRESSURE PASSING ACROSS THE GREAT
LAKES SHOULD KEEP THE NORTHERN HALF OF OUR AREA DRY. HIGHS WEDNESDAY
WILL BE FROM THE LOWER 80S IN THE WEST TO AROUND 90 DEGREES IN THE
EAST. SLOWLY DRY THINGS OUT WEDNESDAY NIGHT FROM NORTH TO SOUTH. LOW
TEMPERATURES WILL DROP INTO THE UPPER 50S IN THE NORTHWEST MOUNTAINS
TO NEAR 70 DEGREES IN THE PIEDMONT.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 330 PM SATURDAY...
UPPER LEVEL RIDGING WILL SHIFT NORTHWARD FROM THE SOUTHEAST STATES
OVER THE MID ATLANTIC DURING THE SECOND HALF OF THE WEEK...RESULTING
IN BOTH WARMER TEMPERATURES AND WEAKER WINDS ALOFT. THIS WILL MAKE
FOR MORE STABLE CONDITIONS THAT WILL KEEP SHOWER AND THUNDERSTORM
ACTIVITY DISORGANIZED THROUGH THE PERIOD. ANY RAINFALL WHICH
DEVELOPS WILL BE DRIVEN MAINLY BY DAYTIME HEATING...WHICH WILL ALLOW
THIS ACTIVITY TO FIZZLE AFTER SUNSET.
HIGH PRESSURE WILL PASS OFF THE NEW ENGLAND COAST ON THURSDAY...
RESULTING IN A WEAK WEDGING PATTERN WITH EASTERLY FLOW OFF THE
ATLANTIC. THIS WILL LIKELY BE THE DRIEST DAY OF THE PERIOD.
WINDS WILL SHIFT SOUTHWESTERLY AGAIN ON FRIDAY AS ANOTHER COLD FRONT
SINKS SOUTH FROM THE GREAT LAKES. STRONGER FLOW OFF THE ATLANTIC
WILL RESULT IN INCREASED MOISTURE...AND WILL EXPECT SPOTTY SHOWER
AND THUNDERSTORM ACTIVITY DURING THE AFTERNOON AND EVENING.
EXPECT TEMPERATURES TO REMAIN SLIGHTLY ABOVE NORMAL FOR THE PERIOD.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
AS OF 125 AM EDT SUNDAY...
SATELLITE PICTURES SHOWED AN EXPANSIVE BAND OF DEEP MOISTURE FROM
THE GULF OF MEXICO INTO THE GREAT LAKES. AXIS OF VORTICITY ALONG
THIS SAME CORRIDOR WILL GENERATE SHOWERS AND THUNDERSTORMS TODAY
AND TONIGHT. ONGOING SHOWERS AND THUNDERSTORMS OVER THE TENNESSEE
AND OHIO VALLEYS EARLY THIS MORNING WILL GRADUALLY MOVE EAST IN TO
WEST VIRGINIA AND VIRGINIA TODAY. LOWER CONFIDENCE AS TO HOW FAR
EAST THIS PRECIPITATION WILL GET BY 00Z/8PM. FOR NOW HAVE LEFT
PRECIPITATION OUT OF THE KBCB AND KROA TAFS. ALSO KEPT KLYH AND
KDAN DRY. HIGHER CONFIDENCE THAT KLWB AND KBLF WILL HAVE A
PROLONGED PERIOD OF SHOWERS OVERNIGHT.
MODELS BRING IFR CEILINGS INTO KLYH AND KDAN EARLY THIS MORNING.
EXPECT ANY STRATUS THAT DOES DEVELOP WILL LIFT TO VFR SHORTLY
AFTER SUNRISE.
EXTENDED DISCUSSION...
IMPULSES EXIT BY MONDAY LEAVING THE REGION IN BETWEEN THIS
EXITING SYSTEM AND THE NEXT UPSTREAM COLD FRONT. THIS SHOULD ALLOW
FOR MORE IN THE WAY OF WIDESPREAD VFR ON MONDAY AFTER EARLY FOG
FADES WITH ONLY ISOLATED CONVECTION LIKELY DURING THE AFTERNOON
INCLUDING SPOTTY MVFR.
ANOTHER COLD FRONT IS EXPECTED TO PRODUCE SIMILAR CONDITIONS AS IT
APPROACHES FROM THE NW TUESDAY...THEN PERHAPS BETTER COVERAGE OF
SHRA/TSRA WEDNESDAY WITH THE FRONT PASSING...AND ACROSS THE SOUTH
THURSDAY WHERE THE BOUNDARY LOOKS TO STALL. HOWEVER TIMING AND
SOUTHWARD EXTENT OF THE BOUNDARY QUITE LOW CONFIDENCE AT THIS
POINT. THUS APPEARS MAINLY VFR FOR NOW TUE-THU OUTSIDE OF
AFTERNOON/EVENING CONVECTION AND TYPICAL EARLY MORNING FOG IN THE
VALLEYS AND WHERE EARLIER HEAVY RAIN OCCURRED.
&&
.EQUIPMENT...
AS OF 730 AM EDT FRIDAY ...
THE VISIBILITY SENSOR AT KDAN...DANVILLE REGIONAL AIRPORT...WILL
BE OUT OF SERVICE UNTIL FURTHER NOTICE. A PART HAS BEEN BACK-ORDERED.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...KK
LONG TERM...NF
AVIATION...AMS
EQUIPMENT...AMS
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
944 AM MDT SUN AUG 31 2014
.UPDATE...
ISSUED AT 924 AM MDT SUN AUG 31 2014
WATER VAPOR IMAGERY SHOWING STRONG UPPER TROF AXIS MOVING THROUGH
SOUTHWEST WYOMING THIS MORNING. AHEAD OF THE TROF SCATTERED
SHOWERS AND A FEW THUNDERSTORMS CONTINUE TO MOVE EAST ACROSS
NORTHERN PORTIONS OF CWA AND ACROSS THE MOUNTAINS. LATEST RAP SHOWING
MODEST QG ASCENT OVER NORTHERN COLORADO WITH THE TROF AND THIS
WILL CONTINUE THROUGH THE AFTERNOON. INITIAL COLD FRONT HAS MOVED
THROUGH MUCH OF NORTHEAST COLORADO AS WINDS HAVE SHIFTED NORTHEAST
WHILE MAINTAINING DEWPOINTS IN THE UPPER 40S TO MID 50S.
MAIN CHANGE TO ZONES WAS TO INCREASE CHANCES OF
SHOWERS/STORMS THIS MORNING AND AFTERNOON OVER THE MOUNTAINS AND
FAR NORTHERN PLAINS. WOULD NOT BE SURPRISED TO SEE A FEW SEVERE
STORMS OVER THE NORTHEAST PLAINS GIVEN MODERATE ASCENT WITH JET
STREAK AND AMPLE LOW LEVEL MOISTURE. FORECAST SOUNDINGS INDICATE
1000-1500J/KG OF CAPE POSSIBLE ESPECIALLY OVER THE PLAINS. WINDS
TO 70 MPH AND SMALL HAIL WOULD BE THE MAIN THREAT GIVEN THE STRONG
MID LEVEL FLOW OF 50KT AT 500MB.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 205 AM MDT SUN AUG 31 2014
TROUGH AND COLD FRONT WILL MOVE ACROSS COLORADO TODAY. DECENT BAND
OF SHOWERS WITH A SHARP WIND SHIFT MOVING INTO THE NORTHERN
MOUNTAINS NOW...THIS SHOWER BAND HAS HAD 40 MPH WINDS WITH IT
ACROSS SOUTHERN WYOMING...PROBABLY NOT AS STRONG FURTHER SOUTH BUT
EXPECT SOME WEST TO SOUTHWEST WIND WITH IT AS IT MOVES ACROSS THIS
MORNING. THERE SHOULD BE ADDITIONAL SHOWER BANDS MUCH OF THE DAY
OVER THE MOUNTAINS...WHILE WEST WINDS WILL LIMIT PRECIPITATION
EAST OF THE FRONT RANGE THROUGH MIDDAY. WIND SHIFT TO A MORE
NORTHERLY DIRECTION AND THE TROUGH AXIS COME THIS AFTERNOON AND
THAT WOULD BE THE BEST CHANCE OF STORMS EAST OF THE MOUNTAINS. BY
SUNSET THE TROUGH SHOULD BE EAST OF THE STATE AND THE SHOWERS
SHOULD BE EXITING. CAPES WILL BE VERY LOW SO ONLY EXPECTING THE
WIND WITH THE SHOWERS OVER MOST OF THE AREA TODAY. GENERALLY
EXPECTING GUSTS IN THE 30-40 MPH RANGE THOUGH THERE IS POTENTIAL
FOR NEAR SEVERE GUSTS IN ORGANIZED LINES...NOT EXPECTING THAT MUCH
PRECIP THOUGH SO A LOW THREAT. NEAR THE EASTERN BORDER CONVECTION
MAY BE A BIT STRONGER WITH BETTER MOISTURE...AGAIN MAINLY A WIND
THREAT BUT MORE OF A CHANCE OUT THERE.
WITH THE CLOUD COVER AND SOME COLD ADVECTION THIS AFTERNOON HIGHS
WILL BE LOWER...CURRENT FORECAST LOOKS GOOD. I LOWERED TEMPS A
LITTLE TONIGHT WITH CLEARING...DRIER AIR...AND DIMINISHING WINDS
IN MOST AREAS.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 205 AM MDT SUN AUG 31 2014
STRONG WEST-NORTHWESTERLY FLOW ALOFT IS PROGGED OVER THE CWA
MONDAY WITH THE UPPER TROUGH AXIS EAST OF COLORADO. THE JET LEVEL
FLOW DECREASES AND BECOMES ZONAL MONDAY NIGHT THROUGH TUESDAY
NIGHT. DOWNWARD SYNOPTIC SCALE ENERGY IS PROGGED OVER THE FORECAST
AREA ON MONDAY...WEAKER...BUT STILL DOWNWARD MONDAY NIGHT THROUGH
TUESDAY NIGHT. THE LOW LEVEL WINDS LOOK TO BE WEAK UPSLOPE MONDAY
INTO MONDAY EVENING...THEN NORMAL DIURNAL PATTERNS TAKE OVER. THE
PLAINS HAVE FAIRLY STRONG SOUTHERLY WINDS PROGGED ON TUESDAY.
MOISTURE IS NOT GREAT THROUGH THE PERIODS...BUT THERE IS SOME
PROGGED AT THE LOWER LEVELS OF THE PLAINS. THE PRECIPITABLE WATER
VALUES ARE GENERALLY FROM THE 0.30 TO 0.80 INCH RANGE THROUGHOUT.
THE BOUNDARY LAYER DEW POINT READINGS RANGE FROM THE 20S F WEST TO
LOWER 50S F EAST THROUGH THE PERIODS. THERE IS TINY BIT OF CAPE
PROGGED OVER THE PLAINS MONDAY AFTERNOON...WITH CONSIDERABLY MORE
PROGGED MAINLY FOR THE PLAINS ON TUESDAY AND TUESDAY EVENING.
CONCERNING MEASURABLE RAINFALL ON THE QPF FIELDS...THERE ARE TINY
AMOUNTS PROGGED HERE AND THERE NOW AND THEN FROM THE VARIOUS
MODELS MONDAY THROUGH TUESDAY NIGHT...BUT IT IS VERY
INSIGNIFICANT. FOR POPS...WILL GO WITH 0-10%S THROUGH THE PERIODS.
FOR TEMPERATURES...MONDAY`S HIGHS ARE 1-3 C COLDER THAN TODAY`S
EXPECTED READINGS. TUESDAY`S HIGHS ARE 2-5 C WARMER THAN MONDAY`S.
FOR THE LATER DAYS...WEDNESDAY THROUGH SATURDAY...THE MODELS HAVE
THE UPPER RIDGE CENTERED IMMEDIATELY SOUTH-SOUTHEAST OF COLORADO
ALL FOUR DAYS. THE FLOW ALOFT IS WEST-SOUTHWESTERLY ALL FOUR
DAYS. MOISTURE INCREASES A BIT THURSDAY INTO NEXT WEEKEND. MODELS
ALSO SHOW UPSLOPE EAST OF THE DIVIDE FROM LATER THURSDAY THROUGH
SATURDAY.
&&
.AVIATION...(FOR THE TAFS THROUGH 18Z MONDAY MORNING)
ISSUED AT 924 AM MDT SUN AUG 31 2014
STILL SOME UNCERTAINTY ON HOW MUCH CONVECTION WILL SURVIVE ACROSS
THE LOCAL TERMINALS AS UPPER TROF MOVES ACROSS THE REGION THIS
AFTERNOON. INITIALLY...WE HAVE SOME UPSLOPE FLOW AS LOW LEVEL
MOISTURE REMAINS HIGH. HOWEVER AS BANDS OF SHOWERS MOVE OFF THE
MOUNTAINS THERE WILL BE MORE DOWNSLOPE WINDS DEVELOPING FROM THE
NORTHWEST. THIS WILL DRY THINGS OUT WITH LESSER CHANCES OF
THUNDERSTORMS. WILL MAINTAIN TEMPO GROUPS FOR THE HIGHER WINDS AS
THE MAIN THREAT. RAPID CLEARING BEHIND THE TROF EARLY THIS EVENING
WITH CLEARING SKIES.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...ENTREKIN
SHORT TERM...GIMMESTAD
LONG TERM...RJK
AVIATION...ENTREKIN
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
607 AM EDT SUN AUG 31 2014
.SYNOPSIS...
HIGH PRESSURE WELL OFF THE EAST COAST WILL MAINTAIN A SOUTHWESTERLY
FLOW OVER THE AREA THROUGH THE FIRST PART OF THE WEEK. A WEAK COLD
FRONT IS THEN EXPECTED TO MOVE ACROSS OUR AREA TUESDAY NIGHT AND
EARLY WEDNESDAY. HIGH PRESSURE WILL BUILD IN BEHIND THIS FRONT FOR
THE SECOND HALF OF THE WEEK. ANOTHER COLD FRONT MAY APPROACH FROM
THE WEST NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
OUR REGION WILL MAINLY BE CAUGHT BETWEEN SYSTEMS TODAY, AS AN
UPPER-LEVEL RIDGE REMAINS SITUATED TO OUR SOUTH AND SOUTHEAST WITH
SURFACE HIGH PRESSURE TO THE EAST. MEANWHILE, AN UPPER-LEVEL TROUGH
WILL CONTINUE TO TRACK ACROSS THE GREAT LAKES THEN ACROSS SOUTHERN
ONTARIO CANADA. THIS WILL RESULT IN A DEEP SOUTHWESTERLY FLOW, WHICH
WILL PULL AN ABUNDANCE OF MOISTURE INTO OUR REGION. AS A RESULT, A
MORE HUMID DAY IS EXPECTED.
THE PRESENCE OF SOME WAA COMBINED WITH THETA-E ADVECTION IS HELPING
TO PRODUCE A DECENT AMOUNT OF CLOUD COVER. THERE MAY BE SOME BREAKS
IN THIS AS THE FLOW ABOVE THE SURFACE INCREASES SOME, HOWEVER IT
WILL ALSO BE FIGHTING AN INVERSION. THE INITIAL WAA AND INCREASE
IN MOISTURE MAY BE ENOUGH TO RESULT IN SOME ISENTROPIC LIFT TO POP
A FEW SHOWERS THIS MORNING MAINLY ACROSS OUR WESTERN TO NORTHERN
ZONES. THIS SCENARIO WAS LESS CERTAIN AS SOME MODEL GUIDANCE THAT
HINTED AT THIS SEEM TO HAVE LOST A SUBTLE SHORT WAVE RUNNING OUT
AHEAD OF THE MAIN FEATURE. THE HRRR HAD THE RIGHT IDEA, BUT SO FAR
IT IS OVERDONE WITH THE COVERAGE. THERE WAS HOWEVER A SMALL GROUP
OF SHOWERS THAT DEVELOPED IN THE LEHIGH VALLEY BUT THEN DISSIPATED
AS IT MOVED NORTHEASTWARD. ANOTHER ISOLATED SHOWER CANNOT BE RULED
OUT EARLY, BUT OTHERWISE THE MAIN POPS WERE DELAYED SOME AND THEN
WERE GRADUALLY EXPANDED AND INCREASED EASTWARD WITH TIME.
AS WE STEP FORWARD THROUGH THE DAY, ENOUGH HEATING COMBINED WITH
CLIMBING SURFACE DEW POINTS SHOULD RESULT IN ENOUGH INSTABILITY
/MLCAPE UP TO 1500 J/KG/ TO PRODUCE SHOWERS AND THUNDERSTORMS. THE
BULK OF THIS ACTIVITY IS EXPECTED TO DEVELOP TO OUR WEST NEAR A WEAK
FRONTAL BOUNDARY WITH ADDITIONAL DEVELOPMENT POSSIBLY NEAR A
DIFFERENTIAL HEATING ZONE. THE HEIGHT FALLS ARE WEAK THIS FAR EAST
AS THE SHORT WAVE TROUGH TRACKS TO OUR NORTH LATE IN THE DAY.
HOWEVER, AN INCREASE IN THE MID LEVEL FLOW TO NEAR 40 KNOTS WILL
INCREASE THE SHEAR WITH TIME. THIS SHOULD BE ENOUGH TO PROMOTE SOME
STORM ORGANIZATION WITH THE MAIN MODE BEING LINE SEGMENTS. IN
ADDITION, THE PW VALUES ARE FORECAST TO INCREASE TO AROUND 2 INCHES
WHICH WILL LEAD TO DOWNPOURS. THESE DOWNPOURS MAY RESULT IN BRIEF
POOR DRAINAGE FLOODING, HOWEVER THE FLASH FLOOD THREAT GENERALLY
LOOKS LOW AS THERE SHOULD BE ENOUGH OF A STORM MOTION.
THE MOIST ENVIRONMENT COMBINED WITH ENOUGH INSTABILITY COULD ALSO
RESULT IN SOME STORMS PRODUCING FREQUENT LIGHTNING. GIVEN THE
FORECAST THERMODYNAMIC SETUP, SOME STORMS WILL BE CAPABLE OF
PRODUCING GUSTY TO PERHAPS LOCALLY DAMAGING WINDS. THIS GENERALLY
LOOKS TO BE FROM ABOUT THE INTERSTATE 95 CORRIDOR ON NORTH AND WEST
BY LATE AFTERNOON. WE THEREFORE MAINTAINED INCREASING POPS FROM WEST
TO EAST WITH THE WESTERN ZONES GOING TO LIKELY IN THE AFTERNOON, AND
WE ALSO ADDED SOME ENHANCED WORDING. MUCH OF THE EASTERN AND
SOUTHEASTERN ZONES MAY REMAIN DRY FOR THE BULK OF THE DAY.
AS FOR HIGH TEMPERATURES, WE USED AN EVEN BLEND OF THE NAM/GFS MOS
THEN ADJUSTED DOWN A LITTLE BIT FOR SOME AREAS WITH THE IDEA OF LOTS
OF CLOUDS PREVAILING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
THE AFOREMENTIONED SHORT WAVE TROUGH IS FORECAST TO DAMPEN OUT AS IT
TRACKS WELL TO OUR NORTH TONIGHT. THERE IS STILL A TRAIL OF SHORT
WAVES ROLLING UP THE BACKSIDE OF THE UPPER-LEVEL RIDGE WITH ALSO A
WEAKENING FRONTAL BOUNDARY NEARING THE AREA. THE FORECAST SOUNDINGS
INDICATE THAT ENOUGH INSTABILITY IS MAINTAINED FOR AWHILE FOR SOME
SHOWERS AND THUNDERSTORMS TO CONTINUE THROUGH THE EVENING,
ESPECIALLY FROM THE INTERSTATE 95 CORRIDOR ON NORTH AND WEST. A
SOMEWHAT MORE PRONOUNCED SHORT WAVE MAY HELP TO FOCUS A CONVECTIVE
CLUSTER OVERNIGHT, HOWEVER WHERE THIS IS FOCUSED HAS LESS CERTAINTY
WITH IT ATTM. AS THE PW VALUES REMAIN RATHER HIGH, LOCAL DOWNPOURS
COULD PUT DOWN A DECENT AMOUNT OF RAIN HOWEVER ANY FLOOD THREAT
LOOKS BRIEF AND LOCALIZED.
AS MENTIONED ABOVE, SOME STRONG CONVECTION MAY OCCUR IN THE EVENING
WITH LOCALLY GUSTY WINDS POSSIBLE. THIS WOULD BE MORE TIED TO ANY
LINE SEGMENTS THAT ARE ABLE TO MAINTAIN THEMSELVES WITH PERHAPS SOME
ENHANCEMENT FROM WATER LOADED DOWNDRAFTS. OTHERWISE, A WEALTH OF
CLOUDS SHOULD BE AROUND THROUGH THE NIGHT FOR MUCH OF THE AREA ALONG
WITH MUGGY CONDITIONS.
AS FOR LOW TEMPERATURES, AN EVEN BLEND OF THE NAM/GFS MOS WAS
GENERALLY USED.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
UNSETTLED WEATHER IS EXPECTED ON MONDAY WITH CONVECTION STILL
POSSIBLE MOST AREAS THROUGH MOST OF THE DAY. LOCALLY HEAVY RAIN IS
POSSIBLE JUST ABOUT ANYWHERE...BUT LATEST GUIDANCE SUGGESTS NEAR AND
SOUTH AND EAST OF THE I-95 CORRIDOR MIGHT BE FAVORED. ANY FLOODING
SHOULD BE MORE URBAN AND POOR DRAINAGE FLOODING. WITH A CONTINUED
SOUTHWESTERLY FLOW, TEMPERATURES WILL PEAK 5 TO 10 DEGREES ABOVE
NORMAL FOR THE BEGINNING OF SEPTEMBER.
MONDAY NIGHT AND TUESDAY...A LULL IN THE PRECIPITATION IS EXPECTED
LATE MONDAY NIGHT THROUGH TUESDAY AFTERNOON. IF THERE`S ENOUGH
SUNSHINE...TEMPERATURES COULD PEAK OUT IN THE LOW 90S.
TUESDAY NIGHT...SHOWERS AND THUNDERSTORMS...SOME WITH LOCALLY HEAVY
RAIN...CAN BE EXPECTED AS A COLD FRONT SWINGS THROUGH THE AREA FROM
WEST TO EAST.
WEDNESDAY THROUGH FRIDAY...THE AIR MASS BEHIND THE COLD FRONT REALLY
WON`T BE TOO MUCH COOLER COURTESY OF A MID-LEVEL ZONAL FLOW, BUT IT
WILL BE DRIER AND MORE COMFORTABLE. HIGHS ALL THREE DAYS WILL BE
PRIMARILY IN THE LOW TO MID 80S, WHICH IS STILL ABOVE NORMAL.
BEAUTIFUL EARLY SEPTEMBER WEATHER.
SATURDAY...INCREASING CLOUDINESS AS THE DAY WEARS ON AS A COLD FRONT
APPROACHES FROM THE WEST. SHOWERS AND THUNDERSTORMS ARE POSSIBLE
WITH TEMPERATURES STILL ABOVE NORMAL.
&&
.AVIATION /10Z SUNDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
TODAY...AREAS OF MVFR TO LOCAL IFR CEILINGS WILL IMPROVE TO VFR
CEILINGS BY MIDDAY.
AN ISOLATED SHOWER IS POSSIBLE EARLY THIS MORNING MAINLY FROM NEAR
KABE AND KRDG, OTHERWISE SOME SHOWERS AND THUNDERSTORMS ARE EXPECTED
TO CONTINUE TO DEVELOP TO OUR WEST AND OVERSPREAD OUR AREA THIS
AFTERNOON. SOME TIMING WAS INDICATED IN THE TAFS, WITH THUNDER ONLY
MENTIONED AT KABE TO KRDG DUE TO HIGHER CONFIDENCE AS OF NOW. THIS
WILL BE REVISITED LATER THIS MORNING. THERE WILL BE BRIEF TIMES OF
MVFR/IFR VISIBILITIES ESPECIALLY WITHIN SHOWERS AND THUNDERSTORMS
AS DOWNPOURS ARE ANTICIPATED. SOUTH-SOUTHEAST WINDS INCREASING TO
GENERALLY 10-15 KNOTS AND BECOMING SOUTH-SOUTHWEST.
TONIGHT...SHOWERS AND THUNDERSTORMS SHOULD CONTINUE EASTWARD WITH
MUCH OF THE ACTIVITY IN THE EVENING HOURS. AS A RESULT, THERE WILL
BE TIMES OF MVFR/IFR DUE TO DOWNPOURS. IN ADDITION, SOME LIGHT FOG
COULD DEVELOP LATE IF SOME CLEARING OCCURS COMBINED WITH LIGHT
WINDS.
OUTLOOK...
MONDAY INTO MONDAY NIGHT...IFR CONDITIONS EXPECTED WITH SHOWERS AND
THUNDERSTORMS. COVERAGE OF PRECIPITATION DECREASING DURING THE
OVERNIGHT HOURS.
TUESDAY...GENERALLY VFR CONDITIONS EXPECTED DURING THE DAY.
TUESDAY NIGHT...IFR CONDITIONS POSSIBLE AS A COLD FRONT MOVES
THROUGH THE AREA.
WEDNESDAY THROUGH FRIDAY...GENERALLY VFR CONDITIONS EXPECTED.
&&
.MARINE...
A SOUTHERLY FLOW IS EXPECTED THROUGH TONIGHT AHEAD OF A WEAKENING
FRONTAL BOUNDARY AS A DISTURBANCE TRACKS WELL TO OUR NORTH. AS THIS
OCCURS, THE FLOW IS FORECAST TO INCREASE AND THIS OPENS THE DOOR TO
SOME MIXING. IT APPEARS THAT THE WARM AIR ADVECTING ACROSS THE AREA
WILL KEEP THE STRONGER WINDS ABOVE THE SURFACE. WHILE THERE CAN BE
SOME GUSTINESS ESPECIALLY NEARSHORE, IT GENERALLY LOOKS MARGINAL.
THE SOUTHERLY FLOW WILL ALSO ALLOW THE SEAS TO BUILD THROUGH
TONIGHT, HOWEVER GIVEN THE SOUTHERLY FLOW DIRECTION AND FETCH, WE
KEPT SEAS UP TO 4 FEET. THEREFORE, NO SMALL CRAFT ADVISORY HAS BEEN
ISSUED AT THIS TIME. SOME SHOWERS AND THUNDERSTORMS WILL ARRIVE LATE
THIS AFTERNOON AND TONIGHT, AND SOME STORMS COULD PRODUCE LOCALLY
GUSTY WINDS.
OUTLOOK...
MONDAY AND MONDAY NIGHT...WINDS AND SEAS SHOULD REMAIN JUST BELOW
SMALL CRAFT ADVISORY CRITERIA. GUSTIER WINDS POSSIBLE IN THE
VICINITY OF THUNDERSTORMS.
TUESDAY THROUGH THURSDAY...WINDS AND SEAS EXPECTED TO REMAIN BELOW
SCA CRITERIA. HOWEVER, SOME GUSTY WINDS ARE POSSIBLE WITH
THUNDERSTORMS TUESDAY NIGHT AND EARLY WEDNESDAY.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MIKETTA
NEAR TERM...GORSE
SHORT TERM...GORSE
LONG TERM...MIKETTA
AVIATION...GORSE/MIKETTA
MARINE...GORSE/MIKETTA
AREA FORECAST DISCUSSION...CORRECTED
NWS TAMPA BAY RUSKIN FL
1100 AM EDT SUN AUG 31 2014
.UPDATE...
15Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS A PROGRESSIVE NORTHERN
STREAM PATTERN ACROSS THE CONUS OVER THE TOP OF AN ELONGATED WEST TO
EAST ORIENTED UPPER RIDGE EXTENDING FROM NORTHERN MEXICO...ACROSS
THE DEEP SOUTH AND INTO THE WESTERN ATLANTIC. POTENT SHORTWAVE /
MOMENTUM PUSH IS SEEN IN WV IMAGERY EJECTING OUT OF THE
INTER-MOUNTAIN WEST ACROSS THE NORTHERN PLAINS. THIS ENERGY IS
EXPECTED TO RESULT IN A LARGE AREA OF SEVERE POTENTIAL ACROSS THE
NORTHERN PLAINS/UPPER MS VALLEY LATER TODAY INTO TONIGHT. CLOSER TO
HOME WE FIND OUR REGION UNDERNEATH THE ELONGATED UPPER RIDGE
MENTIONED ABOVE...AND THIS RIDGE WILL BE STAYING PUT FOR THE NEXT
SEVERAL DAYS. A SWATH OF MID/UPPER LEVEL DRIER AIR IS CLEARLY SEEN
ON WV IMAGERY ARRIVING OVER THE FL PENINSULA FROM THE EAST...
ALTHOUGH THE 12Z KTBW SOUNDING PROFILE WAS LAUNCHED AHEAD OF THIS
PUSH...AND LIKELY DID NOT SAMPLE MUCH OF THE THIS AIRMASS THAT IS
NOW STREAMING OVERHEAD. EVEN STILL...THE 12Z SOUNDING WAS ALREADY
DRIER THAN 24 HOURS AGO WITH A PW VALUE DOWN A FEW TENTHS OF AN INCH
TO AROUND 1.7".
CONVECTIVE POTENTIAL TODAY IS A BIT TRICKY. NO DOUBT THAT WE WILL
SEE STORMS DEVELOPING IN THE FAVORED EASTERLY FLOW...HOWEVER...
TODAYS COLUMN PER THIS 12Z SOUNDING IS NOT AS FAVORABLE FOR
SUSTAINED DEEP CONVECTION AS WAS SEEN ON SATURDAY. THE MID LEVELS
TODAY ARE A BIT WARMER AND ALSO A BIT DRIER. IN ADDITION...THE LOWER
LEVELS BELOW 700MB SHOW A BIT OF A WARM/DRY BUBBLE/CAP. DO NOT THINK
THAT THIS CAP WILL BE ENOUGH TO STOP CONVECTION...BUT SHOULD
CERTAINLY WORK TO DELAY ITS ONSET. WILL NEED TO MIX THE BOUNDARY
LAYER A BIT HIGHER TO OVERCOME THIS CIN COMPARED TO YESTERDAY. FEEL
THIS LATER DEVELOPMENT WILL BE THE MAIN DIFFERENCE BETWEEN YESTERDAY
AND TODAY.
SO...THE COLUMN IS A BIT DRIER...BUT NOT ENOUGH TO BE CONSIDERED
HOSTILE TO DEEP CONVECTION. ONE CONCERN WITH HAVING TO MIX OUT THE
LOWER LEVELS MORE TO REACH THE CONVECTIVE TEMPERATURE IS THAT WE
WILL END UP WITH A DEEPER INVERTED V SIGNATURE / MIXED LAYER BY LATE
AFTERNOON. THESE HIGHER CLOUD BASES AND DEEP WELL MIXED LAYER WILL
PROMOTE AN ENHANCED WIND THREAT WITH THESE LATE DAY STORMS. AS
MENTIONED ABOVE...WE ARE SEEING A WELL DEFINED EAST TO SOUTHEAST
1000-700MB SYNOPTIC FLOW TODAY...AND THIS PATTERN IS FAVORED FOR
CONVECTIVE DEVELOPMENT ALONG THE I-75 CORRIDOR AS THE FLOW INTERACTS
WITH A FEEBLE WEST COAST SEA-BREEZE.
HIRES CONVECTIVE ALLOWING SUITE OF MODELS SEEM TO BE PINNING THE
I-75 CORRIDOR FROM AROUND TAMPA BAY AND SOUTHWARD FOR THE GREATEST
COVERAGE OF STORMS DURING THE LATE AFTERNOON/EARLY EVENING. MANY OF
THESE MEMBERS ARE MUCH LESS AGGRESSIVE UP ALONG THE NATURE COAST.
NOW THERE IS DEFINITELY A TREND HERE...BUT OVERALL DO NOT SEE MUCH
DIFFERENCE IN AIRMASS. PERHAPS A BIT GREATER OVERALL SUPPRESSION IN
CLOSER PROXIMITY TO THE UPPER RIDGE AXIS IS MAKING A DIFFERENCE IN
THESE SIMULATIONS...BUT THIS SHOULD BE MINOR. WITH THE MORNING
FORECAST UPDATE HAVE KEEP RAIN CHANCES LATER TODAY OUT OF THE LIKELY
RANGE (GREATER THAN 60%) TO THE NORTH OF PASCO COUNTY...BUT DO NOT
FEEL COMFORTABLE GOING LESS THAN CHANCE 40-50% FOR THESE NORTHERN
ZONES. HOWEVER...SIMILAR TO SATURDAY...AS YOU HEAD NORTH THROUGH THE
NATURE COAST...MUCH OF THE STORM ACTIVITY SHOULD BE INTO THE EVENING
HOURS. IN CONTRAST...THE AREAS SOUTH OF TAMPA BAY...ESPECIALLY
HIGHLAND COUNTY OVER TO THE FORT MYERS AREAS WILL BE FIRST TO SEE
THE CONVECTIVE INITIATION DURING THE EARLY TO MIDDLE AFTERNOON
HOURS.
THE MORNING SOUNDING SHOWS DEEP LAYER EAST/SE FLOW THROUGH THE
COLUMN...AND THE RAP KEEPS THIS GOING THROUGH THE DAY.
THEREFORE...THERE IS LITTLE DOUBT IN THE PREVAILING STORM MOTION
FROM ESE TO WNW TODAY. BOATERS ON THE COASTAL WATERS SHOULD KEEP A
CLOSE EYE TO THE EAST LATE THIS AFTERNOON/EARLY EVENING AS ANY
STORMS WILL BE MOVING QUICKLY IN YOUR DIRECTION AND PUSHING OFFSHORE
WITH TIME.
ANY LINGERING STORMS WILL BE QUICKLY EXITING INTO THE GULF WITHIN A
COUPLE HOURS OF SUNSET...WHICH WILLS SET UP A MOSTLY DRY AND
SEASONABLE OVERNIGHT PERIOD.
THE OVERALL SYNOPTIC PATTERN DOES NOT CHANGE MUCH HEADING INTO LABOR
DAY...AND HENCE NEITHER WILL THE FORECAST. EASTERLY FLOW WILL
PROMOTE A QUIET MORNING AND THEN MAINLY LATE AFTERNOON/EVENING
STORMS. MORE ON THE MONDAY DETAILS WITH THE AFTERNOON DISCUSSION.
HAVE A GREAT SUNDAY AND WATCH OUT FOR THOSE GUSTY LATE DAY STORMS.
&&
.AVIATION...
VFR CONDITIONS PREVAIL ACROSS THE FORECAST AREA LATE THIS MORNING AS
WE AWAIT MORE LATE DAY STORMS. STORMS LATE THIS AFTERNOON AND EARLY
EVENING WILL HAVE AN ENHANCED WIND THREAT. OTHERWISE...AWAY FROM THE
STORMS EXPECT VFR CONDITIONS TO CONTINUE. STORMS WILL PUSH OFFSHORE
WITHIN A COUPLE HOURS OF SUNSET.
&&
.MARINE...
EAST SOUTHEAST WINDS LESS THAN 15 KNOTS AND SEAS LESS THAN 3 FEET
WILL CONTINUE FOR THE NEXT SEVERAL DAYS AS HIGH PRESSURE OVER THE
ATLANTIC RIDGES WEST OVER THE FLORIDA PENINSULA. THE SEA BREEZE WILL
SET UP ALONG THE COASTLINE EACH DAY TURNING THE WINDS TO AN ONSHORE
FLOW OUT OF THE SOUTHWEST THROUGH NORTHWEST DIRECTION. SCATTERED
SHOWERS AND STORMS WILL BE POSSIBLE EACH DAY DEVELOPING OVER LAND
AND THEN PUSHING WESTWARD OVER THE COASTAL WATERS DURING THE EVENING
HOURS. THE ONLY EXPECTED HAZARD WILL BE GUSTY WINDS AND HIGHER SEAS
IN THE VICINITY OF THUNDERSTORMS.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 93 76 93 78 / 70 30 50 40
FMY 94 75 94 76 / 70 10 50 30
GIF 94 75 94 75 / 40 10 40 10
SRQ 94 74 93 76 / 70 30 50 40
BKV 94 72 94 73 / 50 40 40 30
SPG 93 79 93 80 / 70 40 50 40
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
UPDATE/AVIATION...MROCZKA
MARINE...WYNN
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
948 AM CDT Sun Aug 31 2014
.UPDATE...
ISSUED AT 948 AM CDT SUN AUG 31 2014
A low overcast persists across much of central Illinois along and
east of a Peoria to Jacksonville line this morning. 1430z visible
satellite imagery is showing thin spots developing in the cloud
cover, so am expecting it to dissipate within the next 2 to 3
hours. HRRR ceiling forecast shows this trend quite nicely,
resulting in a partly to mostly sunny afternoon. May see a few
showers/thunder pop up along/south of I-70: however, areal
coverage will remain spotty. Updated the forecast to better
reflect sky cover trends this morning and to confine PoPs to just
the far SE KILX CWA.
&&
.SHORT TERM...(Today and tonight)
ISSUED AT 358 AM CDT SUN AUG 31 2014
Shortwave trough and jet entrance region that brought banded
convection and some locally heavy precipitation to central IL last
evening has shifted northeastward with shower activity nearly ended
over the ILX CWA. With clearing skies and good radiational cooling,
patchy fog will continue to form overnight, mainly I-55
westward.
Moist conditions with enough instability will remain through the
afternoon today for a few showers and thunderstorms, mainly I-70
southeastward, but a relatively dry day expected. Highs in the mid
80s are expected.
After sunset, convection should end quickly across the CWA with the
loss of surface heating. Late in the night, chances for
thunderstorms will spread back into west central Illinois as another
cold front approaches from the west.
&&
.LONG TERM...(Monday through Saturday)
ISSUED AT 358 AM CDT SUN AUG 31 2014
SPC continues a slight risk (15+%) of severe thunderstorms across
central IL nw of a Flora to Robinson line Monday afternoon/evening
for damaging winds and large hail. This seems reasonable considering
surface to 6 km bulk shear values of 30-40 kts, CAPES of 2-3k J/kg.
Heavy rains also possible with thunderstorms in tropical airmass
ahead of frontal boundary. Short waves and 30-40 kt low level jet
moving into IL river valley later Sunday night into Monday morning
and then spreading into eastern IL Monday afternoon/evening. Upper
level trof over northern Rockies moves east into Midwest
Monday/Monday night and drives a cold front southeast across central
IL Monday night. Continued likely pops across much of area Monday
afternoon into Monday night, though diminishing pops overnight
Monday night nw of IL river. Best chances of showers and
thunderstorms lingers over areas from I-72 south on Tue especially
in the morning. The 5% risk of severe storms Tue is southeast of
Lawrenceville. Quite warm and humid Monday ahead of front with highs
82-88F and dewpoints 70-75F and warmest temps in southeast IL where
rain arrives later.
Frontal boundary to weaken as it moves se into Ohio River valley
Tue/Wed with near zonal upper level flow over the region. Carried
just slight chance of convection during midweek from Tue night
through Thu night. Highs in the low to mid 80s Tue/Wed climb into
mid 80s to around 90F Thu/Fri as dewpoints rise back into the low to
mid 70s with heat indices approaching 100F southern counties Thu/Fri
afternoon. Next frontal boundary press southeast into IL Friday
afternoon into Sat and bringing next best chances of showers and
thunderstorms and cooler temps during next weekend.
&&
.AVIATION...(For the 12Z TAFS through 12Z Monday morning)
ISSUED AT 656 AM CDT SUN AUG 31 2014
Mainly IFR/MVFR visibilities this morning due to low ceilings and
areas of fog. Expect improving conditions through 14Z with
conditions generally becoming VFR as surface heating lifts
ceilings and dissipates fog. Isold TSRA to continue until around
00Z mainly K1H2-KPRG southward with potential MVFR cig/vsby and
gusty winds. After 00Z...TSRA ending with VFR conditions across
central/SE Illinois. Toward 12Z Monday...potential TSRA
development KIJX-KPIA westward depending on speed of approaching
system, but probability of TSRA and associated flight category
reductions too low probability before 12Z for mention in TAFS at
this time.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BARNES
SHORT TERM...ONTON
LONG TERM...07
AVIATION...ONTON
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
715 AM CDT SUN AUG 31 2014
...UPDATED LONG TERM SECTION...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 333 AM CDT SUN AUG 31 2014
THE HRRR WAS INDICATING A BROKEN LINE OF RELATIVELY LIGHT
REFLECTIVITY MOVING EASTWARD FROM THE AFOREMENTIONED DEVELOPMENT
ZONE INTO CENTRAL KS BY AROUND 10-12 UTC. THIS SOLUTION WAS FOLLOWED
WITH BASICALLY LOW POPS BELOW 20 PERCENT. THE MORE SIGNIFICANT ISSUE
FOR THE DAY WILL BE A LATE DAY OR EVENING SEVERE WEATHER THREAT. THE
NMM AND ARW MODEL RUNS DEVELOPED A QLCS TYPE BOWING SEGMENT ACROSS
NORTHERN KS, ALONG AND AHEAD OF A COLD FRONT/DRYLINE INTERSECTION
OVER NORTHERN KS. FARTHER SOUTH, OVER OUR AREA, ANY CONVECTION IN
THESE SOLUTIONS COULD BE GENERALLY MORE DISCREET AND MORE HIGH BASED
(HAIL AND WIND THREATS POSSIBLE) WITH SUFFICIENT SHEAR FOR
SUPERCELLS. HOWEVER, IT IS POSSIBLE OUTFLOWS/COLD POOLS COULD FORCE
MORE WIDESPREAD DEVELOPMENT FARTHER BRINGING MORE OF OUR AREA
INTO A SEVERE WEATHER THREAT.
SURFACE WINDS WILL BE MORE BREEZY AHEAD OF THE DRYLINE THIS
AFTERNOON. MODELS SUGGEST 15 TO 20 KNOTS SUSTAINED WINDS WILL BE
COMMON WITH GUSTS IN TO JUST UNDER 30 KNOTS. YESTERDAY`S HIGHS OF
LOW 90S TO MID 90S IN THE SOUTHWEST SECTIONS ARE A REASONABLE TELL
FOR HIGHS TODAY. THE LATEST SHORT TERM CONSENSUS SUPPORTS MID 90S
TO NEAR 100 DEGREES IN THE SW GIVEN THE COMBINATION OF SLIGHTLY
DRIER AIR AND BETTER DOWNSLOPE. WITH THE FRONTAL BOUNDARY AND
POTENTIAL MOIST BOUNDARY LAYER OUTFLOW ACROSS THE AREA TONIGHT, A
LARGE GRADIENT OF AROUND 20 DEGREES COULD EXIST FOR OVERNIGHT LOWS
FROM MID 50`S OUT WEST TO MID 70S IN THE PRATT COLDWATER AND
MEDICINE LODGE AREA SETTING AN EARLY MILD LOW JUST AFTER
MIDNIGHT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 414 AM CDT SUN AUG 31 2014
THE FRONT FOLLOWING TONIGHTS STORM SYSTEM WILL REACH THE TEXAS
PANHANDLE AND ADJACENT WESTERN OKLAHOMA BY LATE MONDAY/MONDAY NIGHT.
THE DAYTIME HOURS MONDAY WILL BE FAIRLY TRANQUIL AS SUBSIDENCE WILL
PREVAIL IN THE WAKE OF THE DEPARTING SYSTEM. MODEST TEMPERATURES IN
THE 80S ARE EXPECTED. THE FRONT WILL STALL OUT MONDAY NIGHT AND WE
WILL FIND OURSELVES IN THE RIGHT ENTRANCE REGION OF AN UPPER
TROPOSPHERIC JET. THIS WILL ENHANCE FRONTOGENESIS IN THE 900-800MB
LAYER, SUPPORTING NOCTURNAL THUNDERSTORMS ONCE THE LOW LEVEL JET
DEVELOPS. THE MOST FAVORABLE LOCATION FOR MONDAY NIGHT/EARLY TUESDAY
STORMS WILL BE ACROSS SOUTH CENTRAL KANSAS, WHICH IS WHERE WE WILL
HAVE THE HIGHEST CHANCE POPS (AROUND 40 PERCENT). THIS FRONTAL ZONE
WILL NOT MOVE TUESDAY, AND WE WILL NEED TO CARRY SOME CHANCE POPS
THROUGH THE DAY ACROSS SOUTH CENTRAL KANSAS. DAYTIME TEMPERATURES
WILL BE AT OR JUST SLIGHTLY ABOVE AVERAGE FOR THE FIRST PART OF
SEPTEMBER (MID TO UPPER 80S AS A RULE). THE FRONT WILL EVENTUALLY
DISSOLVE BY LATE TUESDAY NIGHT AND ESPECIALLY BY WEDNESDAY, AS THE
LOW LEVEL FLOW FIELD BEGINS TO RESPOND TO LOWER PRESSURE MUCH
FARTHER NORTH WHERE THE POLAR JET WILL BE LOCATED. THE NEXT STORM
SYSTEM MID-WEEK WILL BE MUCH FARTHER NORTH WITH WEAK ZONAL FLOW
ACROSS COLORADO AND KANSAS FOR THE MOST PART. THIS WILL LEAD TO
WARMER TEMPERATURES AND DRIER WEATHER. WEDNESDAY AND THURSDAY
CONTINUE TO LOOK LIKE THE HOTTEST DAYS NEXT WEEK WITH AFTERNOON
HIGHS IN THE 95-100F RANGE FOR MUCH OF WESTERN AND SOUTHERN KANSAS.
THE NORTHERN POLAR JET STORM SYSTEM THAT WAS MENTIONED WILL MOVE
EAST ACROSS THE NORTHERN GREAT PLAINS/ADJACENT CANADIAN PRAIRIES
LATE IN THE WEEK, USHERING IN SOME MUCH COOLER TEMPERATURES ACROSS
THE NORTHERN PLAINS. THIS AIRMASS WILL LIKELY REACH KANSAS BY END OF
WEEK AND INTO THE WEEKEND. THERE APPEARS TO BE A FAIRLY STRONG
SIGNAL OF COOLER/WETTER WEATHER SEPTEMBER 6-8 TIME FRAME.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 713 AM CDT SUN AUG 31 2014
STRONG TO SEVERE THUNDERSTORMS WILL DEVELOP ACROSS WESTERN KANSAS
LATE THIS AFTERNOON INTO THIS EVENING. WE WILL GO AHEAD AND
INCLUDE A PROB30 FOR TSRA FOR GCK, DDC, AND HYS FOR A 3 OR 4 HOUR
PERIOD. BY LATE EVENING, THE THUNDERSTORM THREAT WILL MOVE EAST,
LEAVING IN ITS WAKE LIGHTER WINDS FROM THE NORTH.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 98 65 87 65 / 30 50 10 30
GCK 99 62 87 63 / 40 50 10 20
EHA 100 62 91 63 / 10 10 10 10
LBL 102 65 91 64 / 20 20 10 20
HYS 96 64 84 63 / 50 80 20 20
P28 99 71 90 70 / 10 20 20 50
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...RUSSELL
LONG TERM...UMSCHEID
AVIATION...UMSCHEID
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
730 AM EDT SUN AUG 31 2014
.UPDATE...
ISSUED AT 720 AM EDT SUN AUG 31 2014
THE BAND OF RAIN OVER CENTRAL KY IS GRADUALLY WORKING INTO EASTERN
KY. ACTIVITY OVER THE NEXT FEW HOURS SHOULD MAINLY BE ACROSS THE
WESTERN AND NORTHWESTERN LOCATIONS. ACTIVITY SHOULD INCREASE IN
INTENSITY FROM MIDDAY INTO THE AFTERNOON HOURS AND LOCALLY HEAVY RAIN
WILL BE POSSIBLE GIVEN THE VERY MOIST AIRMASS IN PLACE ACROSS THE REGION.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 335 AM EDT SUN AUG 31 2014
EARLY THIS MORNING...THE REGION REMAINED IN A VERY MOIST AIRMASS
WITH PW OF 2 INCHES OR MORE EXTENDING INTO THE OHIO VALLEY REGION
BETWEEN A RIDGE OF HIGH PRESSURE CENTERED OFF THE SOUTHEAST US COAST
AND A SHORTWAVE TROUGH EXTENDING SOUTH FROM THE GREAT LAKES INTO THE
MS VALLEY REGION. A LULL IN THE SHOWER AND THUNDERSTORM ACTIVITY IS
WORKING NORTH AND NORTHEAST ACROSS THE CWA ATTM AS THE FIRST WAVE IS
BEGINNING TO DEPART. HOWEVER...THE NEXT WAVE IS WORKING INTO THE MID
MS AND LOWER OH VALLEY REGION AS THE DEEP MOISTURE PLUME REMAINS.
OVER THE NEXT COUPLE OF DAYS...THE INITIAL WAVE WILL DEPART TO THE
NORTH AND NORTHEAST...BUT THE NEXT MOST EVIDENT AT THE 850 MB AND 700
MB LEVEL IS EXPECTED TO TRACK EAST NORTHEAST ACROSS THE OH VALLEY
REGION TODAY. THIS SYSTEM SHOULD ONCE AGAIN INTERACT WITH THE DEEP
MOISTURE PLUME IN PLACE ACROSS THE REGION AND LEAD TO RENEWED
CONVECTIVE ACTIVITY TO OUR WEST GRADUALLY TRANSITIONING INTO EASTERN KY
LATER TONIGHT AND INTO THE DAY ON SUNDAY. THIS SYSTEM WILL DEPART TO
THE NORTH AND EAST TONIGHT. THE SOUTHEASTERN RIDGE IS EXPECTED TO
FLATTEN BY TONIGHT AND INTO MONDAY. THE NEXT TROUGH WILL HAVE MOVED
INTO THE UPPER MS VALLEY REGION AND PLAINS FROM THE ROCKIES BY LATE
TONIGHT...WITH THIS TROUGH WORKING INTO THE GREAT LAKES AND
APPROACHING THE LOWER OH VALLEY REGION LATE IN THE PERIOD. THE
ASSOCIATED SFC COLD FRONT IS ALSO EXPECTED TO APPROACH THE LOWER OH
VALLEY REGION LATE IN THE PERIOD...BUT WILL HAVE MORE OF AN EFFECT ON
THE LONG TERM PORTION OF THE FORECAST.
RECENT HRRR RUNS BRING THE STRONGEST ACTIVITY ACROSS THE REGION
DURING THE AFTERNOON INTO THE EARLY EVENING ON SUNDAY. THIS ACTIVITY
SHOULD BE EFFICIENT RAIN PRODUCERS AND WHERE ANY TRAINING OCCURS
LOCALLY HEAVY RAIN AND FLASH FLOODING WILL BE POSSIBLE. A FLASH FLOOD
WATCH IS ALREADY IN PLACE ACROSS WESTERN AND NORTHWESTERN PARTS OF
THE CWA ATTM AND WE PLAN TO KEEP IT IN PLACE WITH NO CHANGES. LATER
SHIFTS MAY WANT TO CONSIDER EXTENDING IT FURTHER SOUTH AND EAST...BUT
RAINFALL OVER THE PAST 24 HOURS HAS BEEN GENERALLY LIGHTER THERE
COMPARED TO THE SOUTHWESTERN PART OF THE CWA WHERE RADAR ESTIMATES
AND RAIN GAGES INDICATE THAT UPWARDS OF 2 INCHES OR MORE HAS FALLEN
ACROSS PARTS OF WAYNE COUNTY AND FROM MCCREARY COUNTY NORTHEAST INTO
LAUREL COUNTY. TEMPERATURES TODAY SHOULD BE SUPPRESSED BELOW
SATURDAYS LEVELS BY THE ANTICIPATED CLOUD COVER AND PRECIPITATION.
LOCALLY HEAVY RAIN WILL BE MENTIONED IN THE HWO OUTSIDE OF LOCATIONS
CURRENTLY IN THE FLASH FLOOD WATCH.
WITH THE WAVE DEPARTING TONIGHT...CHANCES FOR CONVECTION WILL ALSO
DIMINISH. MIN TEMPERATURES WILL REMAIN ON THE MILD SIDE. AT LEAST
PATCHY VALLEY FOG SHOULD DEVELOP...WHERE ANY PARTIAL CLEARING
OCCURS. ON MONDAY...THE REGION WILL MORE OR LESS BE IN BETWEEN
SYSTEMS WITH CONTINUED SOUTHERLY FLOW AND NOT MUCH IN THE WAY OF
FORCING. MAX TEMPERATURES WILL AGAIN BE A FEW DEGREES ABOVE NORMAL
AND COULD APPROACH 90 IN SOME LOCATIONS. THE DAYTIME HEATING OF THE
WARM AND RATHER MOIST AIRMASS IN PLACE BY THE AFTERNOON SHOULD LEAD
TO SOME DIURNALLY DRIVEN CONVECTION FOR MONDAY. AT THIS TIME...ONLY
ISOLATED POPS WERE USED.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 252 AM EDT SUN AUG 31 2014
SUMMER-LIKE WEATHER WILL PERSIST THIS WEEK WITH PLENTY OF WARM AND
HUMID CONDITIONS ON TAP. A STRONG RIDGE WILL CONTINUE TO RESIDE OVER
THE SOUTHEAST THROUGH THE WEEK. BEST CHANCE OF RAIN WILL COME ON
TUESDAY AS A SURFACE TROUGH DROPS INTO EASTERN KENTUCKY BEFORE
STALLING. SOME WEAK FORCING WILL YIELD SCATTERED TO NUMEROUS SHOWERS
AND STORMS THROUGH THE AFTERNOON AND EVENING HOURS. DECENT SHEAR
PROFILES...COMBINED WITH MODEST INSTABILITY COULD YIELD THE
POSSIBILITY OF A FEW STRONG TO SEVERE STORMS ON TUESDAY WITH THE
MAIN THREAT BEING DAMAGING WINDS. OTHERWISE...THE FRONT WILL STALL
OVER THE AREA TUESDAY NIGHT...AND VIRTUALLY WASH OUT. THE
THREAT FOR AFTERNOON/EVENING SHOWERS WILL CONTINUE THROUGH WEEKS END
GIVEN THE DAYTIME INSTABILITY EACH AFTERNOON/EVENING. TEMPERATURES
WILL REMAIN NEAR OR SLIGHT ABOVE NORMAL THROUGH THE WEEK WITH ALL
THE COOLER AIR BOTTLED UP WELL TO OUR NORTH.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 725 AM EDT SUN AUG 31 2014
ANOTHER WAVE WILL MOVE NORTHEAST AND INTERACT WITH ABUNDANT MOISTURE
TO BRING A BAND OF RAIN SHOWERS AND SOME EMBEDDED TSRA INTO THE
WESTERN PART OF THE AREA DURING THE FIRST FEW HOURS OF THE PERIOD.
THIS WILL LOWER CIGS GRADUALLY DOWN TOWARD THE MVFR RANGE. AS THE
DISTURBANCE WORKS OVERHEAD THIS AFTERNOON...STRONGER THUNDERSTORMS
MAY DEVELOP WITH LOCALLY HEAVY RAIN. CONFIDENCE IN EXACT TIMING OF
THIS IS LOW AT THIS TIME. CONVECTION SHOULD DIMINISH DURING THE 22Z
TO 4Z PERIOD. PATCHY VALLEY FOG MAY DEVELOP LATE IN THE PERIOD IN THE
DEEPER VALLEYS...BUT MAY NOT AFFECT THE TAF SITES.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 6 PM EDT THIS EVENING FOR KYZ044-050>052-
058>060-068-069-079-080-083>086-104-106-108-111-114-116.
&&
$$
UPDATE...JP
SHORT TERM...JP
LONG TERM...KAS
AVIATION...JP
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
1018 AM EDT SUN AUG 31 2014
.SYNOPSIS...
BERMUDA HIGH PRESSURE WILL PERSIST THROUGH TUESDAY WITH AN ACTIVE
PATTERN FOR THE EASTERN SEABOARD. A WEAK COLD FRONT WILL CROSS THE
AREA TUESDAY NIGHT...FOLLOWED BY HIGH PRESSURE.
&&
.NEAR TERM /THROUGH TONIGHT/...
HIPRES OFF THE EAST COAST OF THE CONUS THIS MRNG. THE ERN SEABOARD
W/IN WARM/HUMID S/SWLY FLOW...AHD OF A CDFNT ACRS SRN CNDA.
STLT/WATER VAPOR IMGRY DEPICT A STREAM OF MSTR AHD OF THE
CDFNT...EMINATING FM THE GLFMEX UP ALONG THE APLCHNS TO THE UPR
OHVLY/ERN GRTLKS. PWAT W/IN THIS ZONE AOA 2 INCHES.
MRNG LWX RAOB DEPICTS AN INVSN ARND H9...BUT A VERY UNSTBL
ENVIRONMENT ABV THAT. DAYTIME HEATING SHUD BE ABLE TO ERODE THE
INVSN...BUT WL AT LEAST HOLD THINGS IN CHECK FOR A LTL WHILE. A
PIECE OF ENERGY HAS BKN OFF FM MAIN STREAM...PROVIDING SHRA TO THE
PTMC HIGHLANDS. RECENT HRRR RUNS SUGGEST THIS WL MAKE IT TO THE
CATOCTINS BEFORE DSPTG...LKLY A RESULT OF THE INVSN. WHILE FULL
SUN TEMPS IN THE MID 90S...ADVANCING CLDCVR LKLY WL KEEP MAXT LWR
THAN THAT. UPDTD TEMPS TO LTST LAMP SINCE POTL CERTAINLY THERE FOR
TEMPS HIER THAN MID-UPR 80S.
USING A TEMP OF 90F AND DEWPTS IN THE LWR 70S...SHUD HV 2000-2500
J/KG CAPE BY LT DAY. BUT...FORCING WL COME IN THE WAY OF PVA/MID
LVL 20-30 KT FLOW...AND THAT WL HOLD OFF TIL AFTR 18Z FOR THE
MTNS...AND CLSR TO 00Z FOR THE CSTL PLAIN. ALSO NEED TO BE MINDFUL
OF THE DIFF HTG BNDRY...WHICH CUD BE ANTHR SOURCE OF INITIATION.
CERTAINLY HV THE DOWNDRAFT POTL FOR STRONG STORMS TDA...BUT DONT
THINK WE/LL BE ABLE TO ACHIEVE FULL POTL. CANNOT RULE OUT LCL WET
MICROBURSTS...BUT BELIEVE THEY WL BE HIT-OR-MISS IN NATURE.
AMPLE MSTR WL ALSO LEAD TO HVY RAINERS...THE OTHER THREAT THIS PM.
RAFL RATES WL BE SUFFICIENT TO LEAD TO A LCL FLASH FLOOD THREAT...
SPCLY UNDER TRAINING CELLS.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY/...
AFTER THE EVE CONVECTION HAS DISSIPATED OFF AND MOVED EAST...
ANOTHER REGIONAL BATCH OF LIGHT/MOD RANGE IS TAGGED BY NEAR TERM
GUIDANCE AS MOVING ALONG THE MASON-DIXON LINE AS WELL - KEEPING
PRECIP CHANCES ALIVE INTO EARLY MON. AS THE BACK END OF THIS
FEATURE PASSES BY TO THE NORTH...PRECIP CHANCES WILL REMAIN IN THE
LOW CHANCE RANGE THRU MON AFTN/EVE ACROSS THE ERN HALF OF THE CWA
BUT MAINLY OF A LIGHT/SCTD NATURE...OUTSIDE OF A FEW TSTMS. THE
RELATIVE LACK OF ACTIVITY AND CLEARING SKIES FROM WEST-TO-EAST
WILL ALLOW TEMPS TO CLIMB BACK INTO THE U80S AND SOME L90S FOR THE
AREA ON MON AFTN...W/ DEWPOINTS STANDING PAT IN THE U60S/L70S -
ANOTHER MUGGY DAY FOR THE AREA.
WEAK RIDGING CROSSES THE CENTRAL MID-ATLANTIC MONDAY NIGHT INTO
TUESDAY...MAKING FOR A REPRIEVE IN THUNDERSTORMS FOR 12-18 HRS. WITH
THE BERMUDA HIGH IN PLACE...EXPECT TUESDAY TO HAVE THE HIGHEST
TEMPERATURE DAY SINCE JULY. MAX TEMPS LOW TO MID 90S ACROSS LOWER
ELEVATIONS.
THE NEXT COLD FRONT APPROACHES LATE TUESDAY AND CROSSES THAT NIGHT.
WITH PLENTY OF ENERGY FROM THE HOT DAY...EXPECT AT LEAST ISOLATED
SEVERE WEATHER...PARTICULAR FOR WRN ZONES THAT ARE PROGGED TO GET
THE EVENING ACTIVITY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
HIGH PRESSURE BUILDS IN BEHIND WITH CONTINENTAL AIR (NOT CANADIAN)
SO TEMPERATURE REMAIN ABOVE NORMAL. EXPECT MAX TEMPS AROUND 90F
WEDNESDAY THROUGH FRIDAY. RETURN FLOW AND ACTIVE WEATHER RETURNS
LATE FRIDAY INTO THE WEEKEND.
&&
.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
MRNG FLGT RESTRICTIONS HV CLRD ACRS THE TERMINALS. SCTD SHRA/TSRA
XPCTD TO DVLP LATER TDA INTO THIS EVNG. LCL IFR PSBL. SCT NATURE
OF THE THREAT LENDS TO VCTS IN TAF ATTM. MORE SPECIFIC
RESTRICTIONS WL BE PLACED INTO FCST WHEN/WHERE APPROPRIATE.
SLY WINDS WILL PERSIST INTO MON...ALONG W/ A FEW HIT/MISS SHOWERS
AS WELL THRU MON EVE.
BRIEF HIGH PRESSURE/VFR TUESDAY ON A HOT DAY (MAX TEMPS IN THE MID
90S). SCATTERED STRONG THUNDERSTORMS TUESDAY NIGHT AS A WEAK COLD
FRONT CROSSES THE REGION. HIGH PRESSURE/VFR OUTSIDE OF POTENTIAL
MORNING FOG MID TO LATE WEEK.
&&
.MARINE...
SLY FLOW ACRS THE MARINE AREA SUN-MON. GUSTS TAFTN WL APPROACH SCA
LIMITS. AM CONSIDERING POSTING ADVY FOR THE AFTN-EVNG. FLOW PTTN
CONTS INTO MON.
SUB SCA SWLY FLOW MONDAY NIGHT THROUGH TUESDAY. WEAK COLD FRONT
BRINGS WLY FLOW LATE TUESDAY NIGHT THROUGH WEDNESDAY. HIGH PRESSURE
OVERHEAD WEDNESDAY NIGHT AND THURSDAY.
&&
.TIDES/COASTAL FLOODING...
DEPARTURES ON THE UPR TIDAL POTOMAC RIVER AND MOST OF THE BAY
HOVERING AROUND 1 FT. LWTV2/SLIM2 ONLY 3/4 FT ABOVE NORMAL. BASED
ON CURRENT TRENDS...THE CURRENT TIDE CYCLE WILL NOT CAUSE
ISSUES...ALTHOUGH ITS MIGHTY CLOSE TO ADVY AT ANNAPOLIS.
WINDS WILL REMAIN SLY THRU THE DAY. THE PM TIDE IS THE HIGHER ONE
ASTRONOMICALLY...SO WL NEED TO CONSIDER ADVYS. WL CONT TO MONITOR.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...BAJ
NEAR TERM...HTS
SHORT TERM...GMS
LONG TERM...BAJ
AVIATION...HTS/GMS/BAJ
MARINE...HTS/GMS/BAJ
TIDES/COASTAL FLOODING...HTS
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
609 AM CDT SUN AUG 31 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 245 AM CDT SUN AUG 31 2014
ALTHOUGH SUNDAY AND ITS POTENTIAL SEVERE WEATHER EVENT ARE
HERE...THE CAMS STILL LEAVE PLENTY OF QUESTIONS AS TO HOW THINGS
WILL EVOLVE LATER TODAY.
FOR THIS MORNING...INITIAL SURGE OF THE LLJ IS MOVING ACROSS THE
DAKOTAS OUT AHEAD OF SHORTWAVE THAT CAN BE SEEN ON WATER VAPOR
MOVING INTO CENTRAL SODAK. ALTHOUGH BEST FORCING AND MOST WIDESPREAD
THUNDERSTORM ACTIVITY CAN BE FOUND AT THE NOSE OF THE LLJ ACROSS
NODAK AND ON ITS WAY TO NW MN...ENOUGH THETA-E ADVECTION AND
ISENTROPIC LIFT IS PRESENT ON THE ERN FLANK OF THE LLJ TO GET SCT
CONVECTION DOWN INTO NE NEB. THE HRRR/HOPWRF/MPXWRF/NMM/ARW ALL SHOW
THIS BAND OF ISO/SCT SHOWERS WORKING ACROSS MN THROUGH THE
MORNING...SO WORKED SOME 20/30 POPS ACROSS MN THIS MORNING TO
ACCOUNT FOR THAT. EXPECT THIS ACTIVITY TO START WEAKENING AS IT
MOVES EAST ACROSS MN AND LIKELY WILL NOT MAKE IT INTO WI AS IT
ENCOUNTERS A PROGRESSIVELY DRIER AIRMASS /SEE 00Z SOUNDING FROM MPX
LAST NIGHT/.
IN THE WAKE OF THIS MORNING ACTIVITY...H85 TEMPS WILL BE INCREASING
TO AROUND 20C. LOOKING AT BUFKIT SOUNDINGS FROM ACROSS THE
AREA...THIS WILL PUT A DECENT CAP IN PLACE THAT LOOKS TO KEEP A LID
ON SURFACE BASED CONVECTION UNTIL ABOUT 00Z. WHERE WE ARE SEEING
SOME VARIABILITY THOUGH WITH THE CAMS IS WITH THE POTENTIAL FOR SOME
ELEVATED CONVECTION TO DEVELOP THIS AFTERNOON OUT AHEAD OF WHAT YOU
COULD CONSIDER THE MAIN SHOW FROM THE SEVERE WEATHER PERSPECTIVE.
THIS ELEVATED CONVECTION LOOKS TO BE TIED TO THE STRONG WAVE ON
WATER VAPOR CURRENTLY MOVING INTO WRN KS. THIS FEATURE HAS A FEW
STORMS ASSOCIATED WITH IT IN KANSAS THIS MORNING AND BY THE
AFTERNOON...THIS WAVE WILL BE NEAR THE MN/IA BORDER. THE CAMS THAT
ARE MOST BULLISH WITH THIS ACTIVITY ARE THE MPXWRF AND ARW...AND
ALTHOUGH IT ENDS AT 21Z...YOU GET A SENSE FROM THE HRRR REFLECTIVITY
FORECAST...IT MAY BE GOING THE SAME WAY IN THE NEXT COUPLE OF RUNS.
THE IMPACT OF THIS ACTIVITY ON THE FORECAST WAS TO SPREAD HIGHER
POPS A BIT FARTHER EAST LATE THIS AFTERNOON THAN THE POSITION OF THE
SFC FEATURES WOULD OTHERWISE SUGGEST.
AS FOR THE POTENTIAL SFC BASED CONVECTION...THE MAIN TREND SEEN WITH
THE CAMS AND 00Z DETERMINISTIC MODELS WAS DELAY ITS START
SOME...WHICH MAKE SENSE GIVEN THE CAPPING SEEN IN THE FORECAST
SOUNDINGS. CURRENT EXPECTATIONS ARE THAT SFC BASED CONVECTION WILL
DEVELOP AROUND 21Z NEAR OMAHA...WHERE INSTABILITY WILL BE
MAXIMIZED...WITH INITIATION ALONG THE FRONT UP IN MN COMING A BIT
CLOSER TO 00Z. GREATEST SEVERE THREAT REALLY LOOKS TO BE DOWN ACROSS
IOWA...WHERE THE COMBINATION OF AN IMPINGING WRLY MID LEVEL JET WITH
A 40-50 KT SWRLY LLJ LOOKS TO MAXIMIZE SHEAR. CAN NOT ARGUE WITH THE
DAY1 SEVERE PROBABILITIES...WHICH HAS THE GREATER SEVERE POTENTIAL
EXISTING FROM I-90 SOUTH. LOOKING AT THE 0-3/0-6 KM SHEAR OF 30-60
KTS WITH VECTORS ORIENTED MOSTLY PERPENDICULAR TO THE FRONT ACROSS
IOWA INDICATES THE POTENTIAL FOR GETTING A STRONG MCS WITH STRONG
WINDS ACROSS IOWA TONIGHT...WHICH IS WHAT THE NMM/ARW CERTAINLY SHOW
EVOLVING. STILL A GOOD DEGREE OF VARIABILITY WITH HOW THIS ACTIVITY
WILL EVOLVE ACROSS THE MPX CWA...WITH SOME SUGGESTION THAT WE MAY
SEE THE GREATEST THUNDERSTORM ACTIVITY SPLIT THE MPX CWA TO THE
NORTH AND SOUTH. CERTAINLY THE HRRR MSLP FORECAST SHOWS SOME MERIT
TO THIS POSSIBILITY...WITH TWO SFC LOWS NOTED BY 21Z. ONE UP IN NRN
MN AND THE OTHER IN WRN KS.
FOR TONIGHT...WE ARE ALSO SEEING THE NMM AND THE ARW TO A LESSER
EXTENT HANGING UP ACTIVITY BACK ACROSS THE CENTER OF THE MPX CWA AS
THEY BOTH DEVELOP A DEFORMATION BAND IN THE WAKE IN THE MAIN COLD
FRONT ACTIVITY. THIS LOOKS TO BE TIED TO THE MAIN SHORT WAVE
POSSIBLY MIXED WITH A BIT OF AN MCV MOVING ACROSS THE UPPER MS
VALLEY LATE TONIGHT. AS A RESULT...HELD ON TO CHANCE POPS A BIT
LONGER BACK ACROSS MOST OF THE MN PORTION OF THE MPX CWA IN THE WAKE
OF THE FRONT. THIS ACTIVITY WOULD NOT HAVE MUCH OF A SEVERE
THREAT...THOUGH IT WOULD SET UP MORE IN A WAY TO ALLOW FOR SOME
TRAINING OF STORMS ALONG A SW TO NE AXIS...SO IT COULD POSE MORE OF
A HYDRO THREAT IF IT MATERIALIZES.
TO SUMMARIZE...WE EXPECT A BAND OF NON-SEVERE SHOWERS/STORMS TO MOVE
ACROSS MN THIS MORNING. STILL A GOOD DEGREE OF UNCERTAINTY WITH
RESPECT THE AFTERNOON ACTIVITY...WITH THE POTENTIAL FOR A PREFRONTAL
TROUGH TO GET ELEVATED CONVECTION GOING BY EARLY AFTERNOON IN THE
EAST...WITH THE GREATEST SEVERE RISK EXISTING FROM ABOUT 6 PM TO
MIDNIGHT FROM SOUTH CENTRAL MN INTO IOWA AHEAD OF THE MAIN SFC COLD
FRONT. EVENTUALLY...A LINE OR TWO OF STORMS LOOKS TO FORM...WITH THE
MAIN SEVERE THREAT BEING DAMAGING STRAIGHT LINE WINDS.
HOWEVER...WHERE ACTIVITY INITIALLY DEVELOPS...IT WILL LIKELY BE
SUPER CELLULAR IN NATURE...WITH LARGE HAIL AND A FEW TORNADOES BEING
POSSIBLE AS WELL...BUT THIS THREAT LOOKS GREATEST FROM ERN NEB INTO
WRN IOWA.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 245 AM CDT SUN AUG 31 2014
THE LONGER TERM WILL INCLUDE SOME ADDITIONAL CHANCES FOR
SHRA/TSRA AS WE SEE THE LARGE SCALE PATTERN ONCE AGAIN BECOME MORE
ZONAL BY THE MIDDLE OF THE WEEK... BEFORE ANOTHER UPPER TROUGH
MOVES INTO THE CENTER OF THE COUNTRY TOWARD THE WEEKEND. THE
MEDIUM RANGE GUIDANCE IS IN FAIRLY GOOD AGREEMENT THROUGH
MIDWEEK... BUT DIVERGES A FAIR AMOUNT BY THE WEEKEND... WHICH
LEADS TO MORE UNCERTAINTY AND NECESSITATES THE INCLUSION OF CHANCE
POPS FOR SEVERAL DAYS.
SOME PCPN WILL LIKELY STILL BE ONGOING ACROSS THE EASTERN PORTION
OF THE AREA ON MONDAY AS THE FRONTAL BOUNDARY SLOWLY PUSHES EAST
INTO THE GREAT LAKES. COULD SEE A FEW SHRA/TSRA SNEAK BACK INTO
THE WESTERN AND CENTRAL PORTION OF THE AREA MONDAY NIGHT INTO
EARLY TUESDAY AS THE UPPER TROUGH/COLD POOL SWING THROUGH THE
REGION. THIS ACTIVITY WILL SHIFT NORTHEAST BY TUESDAY... WITH
RETURN FLOW BEGINNING TO SETUP BY TUESDAY NIGHT. CHANCES FOR
SHRA/TSRA LOOK TO RETURN FROM WEST TO EAST WEDNESDAY INTO THURSDAY
AS A SURFACE LOW SLOWLY TAKES SHAPE OVER THE PLAINS AHEAD OF THE
NEXT UPPER TROUGH... WITH A LONG PERIOD OF MAINLY WEAK ISENTROPIC
LIFT PROGGED ACROSS OUR AREA. THE SPEED WITH WHICH THE SURFACE LOW
MOVES THROUGH OUR AREA VARIES QUITE A BIT AMONGST THE GUIDANCE...
AND AT THIS POINT THERE IS TOO MUCH SPREAD IN THE ENSEMBLE
SOLUTIONS TO HAVE MUCH CONFIDENCE IN ANYTHING SPECIFIC. UNTIL THE
SURFACE LOW AND ASSOCIATED FRONTAL BOUNDARY MOVE THROUGH... WE/LL
CONTINUE TO HAVE A NEED FOR AT LEAST CHANCE POPS. THERE IS ALSO
UNCERTAINTY IN HOW FAR SOUTH THE BOUNDARY WILL BE DISPLACED ONCE
THE SURFACE LOW AND UPPER TROUGH MOVE EAST... WITH THE GUIDANCE
SHOWING VARYING AMPLITUDES OF THE UPPER TROUGH WHICH LEADS TO
DIFFERENCES IN HOW FAR SOUTH THE BOUNDARY IS DISPLACED AS THE
SURFACE HIGH BUILDS INTO THE AREA LATE FRIDAY INTO SATURDAY. AT
THIS POINT... KEPT SOME POPS OVER THE SOUTHERN PART OF THE AREA
INTO SATURDAY TO ACCOUNT FOR THE POSSIBILITY OF THE BOUNDARY
HANGING UP OVER NORTHERN IOWA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 558 AM CDT SUN AUG 31 2014
EXTENSIVE FOG/LOW STRATUS THAT DEVELOPED OVER WI BENEATH THE SFC
HIGH HAS MANAGED TO WORK INTO ERN MN/WRN WI ON SOUTHEAST WINDS
THIS MORNING. AS WINDS CONTINUE TO BECOME MORE SRLY AND PICK UP IN
STRENGTH...WE SHOULD SEE THESE CLOUDS MIX OUT PRETTY QUICK THIS
MORNING. SHOWERS THAT SNUCK INTO WRN MN EARLY THIS MORNING WILL
CONTINUE TO SLOWLY FALL APPART AS THEY WORK ACROSS MN AND FEEL
VCSH MENTIONS AT MN TERMINALS IS ENOUGH FOR THIS MORNING. FOR THE
AFTERNOON...BEGINNING TO FAVOR THE HRRR/ARW TREND FOR STORMS
TODAY...WITH STORMS DEVELOPING NEAR THE MN/WI BORDER AROUND 20Z ON
A LEAD TROUGH...WITH THE MAIN COLD FRONTAL ACTIVITY NOT LOOKING TO
REALLY GET GOING IN MN UNTIL AFTER 00Z. BEHIND THIS
ACTIVITY...GFSLAMP IS WANTING TO DEVELOP LOW STRATUS...BUT 925-850
RH FORECASTS FROM THE NAM/GFS INDICATE THE STRATUS BEING FAVORED
FOR NRN MN...SO KEPT CIGS VFR TONIGHT.
KMSP...CONFIDENCE IS NOT AT THE CERTAIN LEVEL FOR MSP GETTING
STORMS THIS AFTERNOON...AS SEVERAL OF THE CAMS ARE SHOWING
AFTERNOON ACTIVITY MAINLY IMPACTING WI...WHILE STRONGER STORMS
TONIGHT STAY OFF TO THE SOUTH. IT IS THIS SECONDARY ACTIVITY
THOUGH THAT LOOKS TO HAVE THE GREATEST POTENTIAL FOR IMPACTING THE
FIELD...WHICH IS WHY THE TEMPO GROUP IS STILL THERE FROM 1-4Z.
MOVED THE VCTS MENTION UP TO 21Z TO ACCOUNT FOR UNCERTAINTY FOR
WHERE STORMS WILL DEVELOP ALONG THE PREFRONTAL TROUGH THIS
AFTERNOON. GIVEN STRENGTH OF WINDS...SHOULD NOT TAKE TOO LONG TO
MIX OUT LOW STRATUS THIS MORNING...WITH THAT LOOKING TO OCCUR
BETWEEN 14Z AND 15Z.
/OUTLOOK FOR KMSP/
MON...MVFR/TSRA ENDING EARLY. VFR BY AFTERNOON WINDS WNW 5-10 KTS.
TUE...VFR. WINDS WSW 5-10 KTS.
WED...VFR. CHC MVFR/TSRA LATE. WINDS S 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...
AVIATION...MPG
AREA FORECAST DISCUSSION
NWS BILLINGS MT
901 AM MDT SUN AUG 31 2014
.UPDATE...
MINOR UPDATES TO THE FORECAST THIS MORNING...MAINLY TO SLIGHTLY
ADJUST HIGH TEMPERATURES UPWARD FOR THIS AFTERNOON. MAIN WAVE IS
TRACKING FARTHER SOUTH THAN ANTICIPATED...WHICH IS KEEPING RAIN
SHOWER ACTIVITY SUPPRESSED TO THE SOUTH ACROSS WYOMING THIS
MORNING. THUS EXPECT TEMPERATURES WILL BE ABLE TO RISE BETTER
THAN EXPECTED WITH THE LACK OF PRECIPITATION. STILL ANTICIPATE
SOME INSTABILITY SHOWERS TO DEVELOP BY THIS AFTERNOON...BUT THE
ACTIVITY WILL BE FAIRLY SCATTERED.
CHURCH
&&
.SHORT TERM...VALID FOR TDY AND MON...
BROAD CYCLONIC FLOW WILL CONTINUE TO PREVAIL OVER OUR REGION THE
NEXT COUPLE OF DAYS. WE WILL HAVE A COUPLE OF DISTURBANCES WITHIN
THE FLOW ALOFT TRACK THROUGH THE REGION PRODUCING PERIODS OF
SHOWERS AND SCATTERED THUNDERSHOWERS. A SEASONABLY COOL AIR MASS
WILL REMAIN ENTRENCHED OVER THE REGION AS WELL KEEPING HIGHS ABOUT
10 DEGREES COOLER THAN NORMAL.
AS FOR ADJUSTMENTS IN THIS PACKAGE...JET MAX ON THE FRONT END OF
BROADER TROUGH IS WEAKER THAN THE ONE ON THE BACKSIDE WHICH SHOULD
KEEP SOME OF THE ENERGY DIGGING SOUTH EARLY TODAY. THIS WILL KEEP
THE BEST LIFT GENERALLY SOUTH IN NW WYOMING. ONLY THE RAP HAS
PICKED UP ON THIS SO FAR WITH THE GFS/WRF/ECMWF ALL OVERPLAYING
THE PRECIPITATION TOO FAR NORTH. HOWEVER...WE WILL SEE
INSTABILITY SHOWERS DEVELOP AS THE COLD POOL MOVES OVER US THIS
AFTERNOON. WE MAY SEE A BETTER CHANCE OF PRECIPITATION ON THIS
SIDE OF THE STATELINE BY AFTERNOON AS JET STREAM BUCKLES NORTH
WITH EASTWARD MOVEMENT OF UPPER TROUGH AXIS. SO HAVE ADJUSTED
HIGHEST POPS SOUTHWARD THIS MORNING...AND HIT THE SE SECTION
HARDEST LATE MORNING TO THIS AFTERNOON. ANOTHER SHORT WAVE COMES
THROUGH THIS EVENING AND AFFECTS MAINLY OUR WESTERN TERRAIN BEFORE
SPREADING SHOWERS TO THE SOUTHEAST THROUGH MONDAY. TEMPERATURES
WILL REMAIN ON THE COOL SIDE WITH LITTLE CHANGE TO INHERITED
FORECASTS. BT
.LONG TERM...VALID FOR TUE...WED...THU...FRI...SAT...
RELATIVELY MINOR CHANGES TO THE EXTENDED PERIOD THIS MORNING.
ALTHOUGH MODELS ARE IN GOOD AGREEMENT WITH REGARD TO THE OVERALL
PATTERN...TIMING REMAINS A BIT OF AN ISSUE...AND LITTLE HAS
CHANGES FROM PREVIOUS MODELS RUNS. THE TIMING PROBLEMS HAVE
NECESSITATED A MORE BROAD BRUSH APPROACH TO POPS THROUGHOUT THE
PERIOD.
THE EXTENDED FORECAST REMAINS CONSISTENT...STARTING OFF QUIET FOR
WEDNESDAY...WITH ZONAL DOWNSLOPE FLOW ACROSS THE AREA. CONDITIONS
BEGIN TO CHANGE LATE WEDNESDAY AS SYSTEM OVER WESTERN CANADA DIGS
SOUTH AND FLOW TURNS SOUTHWEST OVER MONTANA. A COLD FRONT ALSO
PUSHES INTO THE REGION WEDNESDAY INCREASING THE CHANCES FOR
AFTERNOON AND EVENING THUNDERSTORMS. HAVE EXPANDED POPS COVERAGE
WEDNESDAY EVENING/NIGHT. BROAD TROF REMAINS IN CONTROL OVER THE
REGION INTO NEXT WEEKEND...WHICH KEEPS KEEPS SLIGHT PRECIP
POTENTIAL IN PLACE THROUGHOUT THE PERIOD AS WELL. PERSISTENCE OF
TROF WILL KEEP DAYTIME TEMPS WELL BELOW SEASONAL AVERAGE
THROUGHOUT THE EXTENDED PERIOD...WITH 60S AND 70S THROUGHOUT THE
PERIOD. AAG
&&
.AVIATION...
SCATTERED SHOWERS ARE EXPECTED ACROSS MUCH OF THE REGION TODAY AS
ANOTHER DISTURBANCE CROSSES THE AREA. VFR CONDITIONS WILL PREVAIL
WITH LOCAL MVFR AND OCCASIONAL MOUNTAIN OBSCURATIONS NEAR SHOWER
ACTIVITY. CHAMBERS
&&
.PRELIMINARY POINT TEMP/POPS...
TDY MON TUE WED THU FRI SAT
-------------------------------------------------------
BIL 071 051/070 050/078 054/077 050/069 049/069 050/074
3/T 32/T 00/U 12/T 22/T 22/T 22/T
LVM 068 044/070 043/079 046/077 043/068 044/069 045/076
3/T 42/T 00/U 12/T 22/T 22/T 23/T
HDN 072 051/072 050/080 053/081 051/072 051/073 050/077
2/T 32/T 00/U 12/T 22/T 22/T 22/T
MLS 074 052/074 052/079 054/080 053/071 053/072 052/075
2/T 12/T 00/U 11/U 12/T 22/T 22/T
4BQ 071 051/071 051/080 053/083 052/072 051/073 051/076
4/T 23/T 00/U 12/T 22/T 22/T 22/T
BHK 072 050/072 048/077 051/080 050/073 049/070 049/073
4/T 12/T 00/U 12/T 22/T 22/T 22/T
SHR 068 047/069 046/080 050/083 049/073 048/075 048/078
5/T 33/T 00/U 12/T 22/T 22/T 23/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1112 AM EDT SUN AUG 31 2014
.SYNOPSIS...
A SLOW MOVING TROUGH OF LOW PRESSURE WILL PRODUCE SHOWERS AND A
FEW THUNDERSTORMS TODAY BEFORE SLOWLY TAPERING OFF FROM NORTHWEST
TO SOUTHEAST THIS AFTERNOON. IT WILL REMAIN MUGGY ALTHOUGH
EXTENSIVE CLOUD COVER WILL KEEP TEMPERATURES LOWER THAN YESTERDAY.
A FEW SPOTTY SHOWERS AND THUNDERSTORMS ARE POSSIBLE ON LABOR
DAY...BUT THE MAJORITY OF THE DAY SHOULD BE RAIN FREE WITH
TEMPERATURES WARMING BACK TO A LITTLE ABOVE AVERAGE.
&&
.NEAR TERM /THROUGH TONIGHT/...
RADAR IMAGERY LATE THIS MORNING SHOWS A SOLID AREA OF RAIN ACROSS
CENTRAL NEW YORK...JUST ABOUT TO EXIT EAST OF OUR CWA. BEHIND
THIS...BROKEN LINES OF SHOWERS WITH EMBEDDED THUNDERSTORMS HAVE
DEVELOPED AHEAD OF A WIND SHIFT BOUNDARY WHICH EXTENDS FROM SW-NE
AND IS LOCATED NEAR BUFFALO AT 1100 AM. THIS BOUNDARY WILL
CONTINUE TO MOVE EAST IN ASSOCIATION WITH A MID LEVEL TROUGH. THE
12Z BUF SOUNDING HAS AN IMPRESSIVE 1.83 INCH PWAT...SO SHOWERS AND
THUNDERSTORMS WHICH DO DEVELOP AHEAD OF THIS BOUNDARY WILL PRODUCE
BRIEF HEAVY DOWNPOURS...BUT ARE LIKELY TO MOVE WITH THE BOUNDARY WHICH
SHOULD MITIGATE FLOOD POTENTIAL. IT IS STILL FAIRLY MOIST BEHIND
THIS BOUNDARY...AND WITH A LAKE BREEZE CONVERGENCE BOUNDARY
EXPECTED TO DEVELOP NEAR THE SOUTH SHORES OF LAKE ONTARIO THERE
COULD BE A FEW SHOWERS OR THUNDERSTORMS WHICH DEVELOP ON THIS
BOUNDARY. HOWEVER...MOST MESOSCALE GUIDANCE FROM THE HRRR TO
NAM/RGEM FOCUS THE STEADIEST SHOWERS ACROSS EAST OF EACH
LAKE...OUT AHEAD OF THE BOUNDARY.
SOUTHWESTERLY WINDS WILL PICK UP ACROSS THE NIAGARA FRONTIER THIS
AFTERNOON...WHICH SHOULD PROVIDE AT LEAST A PARTIAL CLEARING BY
MIXING OUT LOW MOISTURE. TEMPERATURES ALOFT ARE STILL WARM...WITH
SURFACE TEMPERATURES LIKELY TO REACH 80 IN ANY AREAS WHICH GET
PROLONGED SUNSHINE. SOUTHERN AND EASTERN PORTIONS OF THE CWA
SHOULD STAY STUCK IN THE CLOUDS...WITH HIGHS AVERAGING IN THE MID
70S.
TONIGHT SHOWERS ACROSS THE SOUTHERN TIER AND CENTRAL NY WILL
CONTINUE TO SLOWLY DIMINISH. ENOUGH INSTABILITY MAY DEVELOP IN THE
WAKE OF THIS MAIN RAIN AREA TO ALLOW SCATTERED THUNDERSTORMS TO FORM
DURING THE LATE AFTERNOON AND EARLY EVENING ACROSS THE NIAGARA
PENINSULA. IF THEY MATERIALIZE...A FEW MAY MAKE IT INTO AREAS JUST
NORTH OF BUFFALO THIS EVENING. SCATTERED STORMS MAY ALSO FORM OVER
SOUTHEAST ONTARIO AND CROSS THE SAINT LAWRENCE INTO THE NORTH
COUNTRY THIS EVENING. OTHERWISE EXPECT SOME PARTIAL CLEARING
OVERNIGHT ON THE LAKE PLAINS. ACROSS THE HIGHER TERRAIN LOW LEVEL
MOISTURE AND WEAK UPSLOPE FLOW AND CONVERGENCE WILL LIKELY SUPPORT
EXPANDING LOW CLOUD COVER. EXPECT LOWS IN THE MID TO UPPER 60S ON
THE LAKE PLAINS AND LOWER TO MID 60S IN THE SOUTHERN TIER AND NORTH
COUNTRY.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
A WARM AND STICKY AIRMASS WILL REMAIN ACROSS THE REGION ON
MONDAY...WITH MOST OF THE FORECAST AREA EXPERIENCING MAINLY DRY
CONDITIONS. HOWEVER THERE WILL BE THE CHANCE FOR SCATTERED SHOWERS
AND THUNDERSTORMS IN THE AFTERNOON AND EVENING...MAINLY ACROSS THE
INTERIOR SOUTHERN TIER WHERE THE BEST INSTABILITY WILL RESIDE. CAPE
VALUES BY LATER IN THE AFTERNOON ACROSS THIS REGION WILL RUN IN THE
1000-1500 J/KG RANGE WITH LI`S POSSIBLY AS LOW AS -4. HOWEVER WITH
WEAK 0-6KM BULK SHEAR (~20KTS) AND LACK OF A GOOD SURFACE TRIGGER
(ASIDE FROM A POSSIBLE LAKE BREEZE)...NOT EXPECTING ANY
THUNDERSTORMS TO REACH SEVERE LIMITS. INSTABILITY LOOKS LOWER ACROSS
THE REMAINDER OF THE AREA...AND THUS CONVECTIVE CHANCES LOOK MUCH
LOWER AS WELL. TEMPERATURES WILL AGAIN BE ON THE WARM SIDE WITH
HIGHS IN THE UPPER 70S TO LOWER 80S.
WITH THE LOSS OF DAYTIME HEATING MONDAY NIGHT MOST OF THE DIURNALLY
DRIVEN CONVECTION WILL DIMINISH IN COVERAGE...ALTHOUGH A FEW STORMS
MAY CONTINUE LATE INTO THE EVENING...ESPECIALLY ACROSS PORTIONS OF
THE SOUTHERN TIER. AT THE SAME TIME A COLD FRONT OVER THE UPPER
GREAT LAKES WILL BE ADVANCING TOWARD THE REGION AND BE LOCATED WEST
OF NEW YORK STATE BY TUESDAY MORNING. THAT SAID...MOST OF THE NIGHT
LOOKS TO REMAIN DRY...WITH PRECIP CHANCES STARTING TO INCREASE A BIT
ACROSS WESTERN NEW YORK TOWARD TUESDAY MORNING. ANOTHER MILD
NIGHT CAN BE EXPECTED WITH LOWS IN THE MID TO UPPER 60S FOR MOST
LOCATIONS THANKS TO DEEP SOUTHERLY FLOW OUT AHEAD OF THE APPROACHING
COLD FRONT.
LATEST GUIDANCE PACKAGE HAS THE COLD FRONT NOW MOVING A BIT SLOWER
THAN IN PREVIOUS RUNS. THIS IS MOST LIKELY DUE TO MOST OF THE MODELS
NOW COMING INTO AGREEMENT ON THE DEVELOPMENT OF LOW PRESSURE
SOMEWHERE IN THE OHIO VALLEY ALONG THE FRONT AND THEN TRACKING IT
NORTHEAST ALONG THE BOUNDARY WHICH WOULD SLOW IT DOWN A LITTLE.
THAT SAID...IT NOW APPEARS IT WILL TAKE THE BULK OF THE DAY TUESDAY
FOR THE COLD FRONT TO SWEEP ACROSS THE REGION WITH SHOWERS AN
THUNDERSTORMS LIKELY...WITH LOWER CHANCE POPS BY LATER IN THE DAY
ACROSS WESTERN NEW YORK. HIGH PRECIPITABLE WATER VALUES OF 1.7"-1.9"
TUESDAY AFTERNOON OFFER THE RISK OF HEAVY DOWNPOURS WITH ANY
THUNDERSTORM. SBCAPES OVER 1000 J/KG COMBINED WITH LIFTED INDEX
VALUES AT -4C TO -5C ALSO POINT TO THE POSSIBILITY OF STORMS. THE
MAIN DIFFERENCES FROM MONDAY ARE THAT 0-6KM BULK SHEAR VALUES LOOK
TO BE IN THE 40-45KT RANGE...AND ALSO HAVE THE SURFACE COLD FRONT
CROSSING THE FORECAST AREA WHICH WILL SERVE AS THE FOCAL POINT FOR
STORMS TO FIRE ALONG. ALL THIS SAID...LOOKS AS THOUGH THERE COULD BE
SOME STRONG STORMS...WITH A FEW STORMS POSSIBLY REACHING SEVERE
LIMITS. MAIN THREATS APPEAR TO BE GUSTY WINDS ASSOCIATED WITH BOWING
LINE SEGMENTS AND MARGINALLY SEVERE HAIL. ANOTHER WARM DAY ON TAP
WITH HIGHS IN THE UPPER 70S TO LOWER 80S.
THE COLD FRONT WILL SLIDE SOUTH AND EAST OF THE FORECAST AREA
TUESDAY EVENING...TAKING THE SHOWERS AND STORMS WITH IT. ALTHOUGH A
FEW SHOWERS WILL STILL BE POSSIBLE DURING THE EVENING ACROSS EASTERN
AREAS...BUT EVEN HERE THINGS WILL DRY OUT LATER TUESDAY NIGHT AS
SURFACE HIGH PRESSURE STARTS TO BUILD EAST ACROSS NEW YORK STATE.
LOWS WILL BE GENERALLY IN THE UPPER 50S TO LOWER 60S.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
UPPER LEVEL RIDGING AND SURFACE HIGH PRESSURE WILL BUILD ACROSS THE
REGION WEDNESDAY AND THURSDAY BRINGING IN DRIER AIR AND TEMPERATURES
THAT WILL STILL AVERAGE AT OR JUST A BIT ABOVE NORMAL FOR EARLY
SEPTEMBER. HIGH PRESSURE WILL THEN SLIDE OFF THE NEW ENGLAND COAST
BY FRIDAY. THIS WILL PROVIDE MAINLY DRY CONDITIONS THROUGH
MIDWEEK...BEFORE THE NEXT FRONTAL SYSTEM APPROACHES FOR LATE IN THE
WEEK AND EARLY WEEKEND. TEMPERATURES WILL BE A BIT ABOVE SEASONAL
NORMALS WITH HIGHS IN THE UPPER 70S TO LOW 80S AND LOWS IN THE LOWER
60S.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
CONDITIONS HAVE LOWERED LATE THIS MORNING...WITH THE APPROACH OF A
SURFACE TROUGH AN IN HEAVIER RAIN SHOWERS. LOW VSBY IN RAIN
SHOWERS...AND A FEW EMBEDDED THUNDERSTORMS SHOULD BE
TEMPORARY. EXPECT A MIX OF MVFR/VFR CIGS AT BUF/IAG/ROC/ART WITH
THE SW WIND SHIFT...WHILE JHW IS LIKELY TO REMAIN IFR OR LOWER AND
THEN IMPROVE WITH THE WIND SHIFT.
TONIGHT ANY SHOWERS AND SCATTERED THUNDER ACROSS THE SOUTHERN TIER
WILL DIMINISH DURING THE EVENING. MAINLY VFR DURING THE EVENING WILL
GIVE WAY TO INCREASING AMOUNTS OF IFR IN LOW STRATUS OVERNIGHT WITH
EXTENSIVE LOW LEVEL MOISTURE FIELDS. EXPECT STRATUS TO FORM FIRST
ACROSS HIGHER TERRAIN...BUT MAY SPREAD TO THE LOWER ELEVATIONS OF
WESTERN NY AS WELL AFTER ABOUT 09Z. AREAS OF FOG AND IFR VSBY ARE
LIKELY ACROSS THE HIGHER TERRAIN OF THE SOUTHERN TIER AND FINGER
LAKES AS WELL WHERE THE LOW STRATUS INTERSECTS THE HILLS.
OUTLOOK...
MONDAY...VFR/MVFR IN SCATTERED SHOWERS AND THUNDERSTORMS.
TUESDAY...SHOWERS AND THUNDERSTORMS LIKELY WITH ASSOCIATED BRIEF
MVFR/IFR. SOME STORMS MAY BE STRONG.
WEDNESDAY AND THURSDAY...VFR.
&&
.MARINE...
MODERATE SOUTHERLIES WILL CONTINUE TO PRODUCE MARGINAL SMALL CRAFT
ADVISORY CONDITIONS AT THE NORTHEAST END OF LAKE ONTARIO FROM GALLOO
ISLAND TO CAPE VINCENT THROUGH EARLY AFTERNOON BEFORE
DIMINISHING. LOW PRESSURE WILL MOVE ACROSS SOUTHERN QUEBEC TODAY
WITH WINDS BECOMING MORE SOUTHWEST ON THE LOWER LAKES. EXPECT
WINDS TO INCREASE ABRUPTLY ON LAKE ERIE THROUGH EARLY
AFTERNOON...WITH A 3 TO 6 HOUR PERIOD OF 15 TO 20 KNOT WINDS AND 3
TO 5 FOOT WAVES AS WINDS ALOFT SHIFT TO THE WSW AND MIX DOWN
AS THEY ENCOUNTER THE CHAUTAUQUA RIDGE. ALSO...THERE IS A
CONVERGENCE BOUNDARY ON LAKE ERIE WHICH HAS THE POTENTIAL TO
PRODUCE WATER SPOUTS THROUGH EARLY AFTERNOON. THIS POTENTIAL WILL
END AS THE BOUNDARY SLIDES FURTHER SOUTH AND OFF THE LAKE.
THE PRESSURE GRADIENT RELAXES ACROSS THE LOWER LAKES TONIGHT AS LOW
PRESSURE DISSIPATES OVER SOUTHEAST QUEBEC. THIS WILL ALLOW WINDS AND
WAVES TO SUBSIDE.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR LEZ040-
041.
SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON
FOR LOZ045.
&&
$$
SYNOPSIS...HITCHCOCK
NEAR TERM...APFFEL/HITCHCOCK
SHORT TERM...JM
LONG TERM...JM/WCH
AVIATION...APFFEL/HITCHCOCK
MARINE...APFFEL/HITCHCOCK
AREA FORECAST DISCUSSION
NWS BUFFALO NY
751 AM EDT SUN AUG 31 2014
.SYNOPSIS...
A SLOW MOVING TROUGH OF LOW PRESSURE WILL PRODUCE OCCASIONAL SHOWERS
AND SCATTERED THUNDERSTORMS ACROSS MUCH OF THE REGION THIS MORNING
BEFORE SLOWLY TAPERING OFF FROM NORTHWEST TO SOUTHEAST THIS
AFTERNOON. IT WILL REMAIN MUGGY ALTHOUGH EXTENSIVE CLOUD COVER WILL
KEEP TEMPERATURES LOWER THAN YESTERDAY. A FEW SPOTTY SHOWERS AND
THUNDERSTORMS ARE POSSIBLE ON LABOR DAY...BUT THE MAJORITY OF THE
DAY SHOULD BE RAIN FREE WITH TEMPERATURES WARMING BACK TO A LITTLE
ABOVE AVERAGE.
&&
.NEAR TERM /THROUGH TONIGHT/...
RADAR IMAGERY THIS MORNING SHOWING A SOLID AREA OF LIGHT RAIN
COVERING MUCH OF THE REGION...WITH A FEW POCKETS OF MODERATE RAIN
ACROSS THE SOUTHERN TIER AND CENTRAL NY. THE WIDESPREAD NATURE OF
THE RAIN IS LIKELY DUE TO MID LEVEL DEFORMATION AND FRONTOGENESIS
FROM A WEAK BAROCLINIC LEAF NOTED IN IR SATELLITE IMAGERY. THIS
STEADY RAIN WILL SHIFT SLOWLY EAST THROUGH THE REGION THROUGH
MIDDAY. THE BACK EDGE IS NEAR KERI-KBUF AT 1130Z...AND MUCH OF THE
NIAGARA FRONTIER WILL MISS OUT ON THE STEADIER RAIN. THAT SAID...
THE BACK EDGE MAY NOT STAY CLEAN WITH MESOSCALE MODEL GUIDANCE SUCH
AS THE HRRR SUGGESTING CONVECTIVE SHOWERS WILL DEVELOP BY LATE
MORNING ACROSS THE NIAGARA FRONTIER JUST WEST OF THE STEADIER RAIN.
FOR TODAY A MID LEVEL TROUGH WILL ADVANCE EAST ACROSS THE CENTRAL
GREAT LAKES...WITH DOWNSTREAM HEIGHT FALLS AND DPVA PRODUCED BY
CONVECTIVELY AUGMENTED VORTICITY MAXIMA AIDING IN LARGE SCALE
ASCENT. UPPER LEVEL DIVERGENCE WILL BE ENHANCED BY THE RIGHT
ENTRANCE REGION OF A 80+ KNOT UPPER LEVEL JET STRETCHING FROM LOWER
MICHIGAN TO SOUTHERN QUEBEC. A BELT OF 30-35 KNOT FLOW IN THE
900-700MB LAYER WILL AID IN ORGANIZING CONVERGENCE AND MOISTURE
TRANSPORT. AT THE SURFACE WEAK/ELONGATED LOW PRESSURE WILL MOVE INTO
SOUTHERN QUEBEC WITH A WEAK PRE-FRONTAL TROUGH EASING ACROSS THE
LOWER LAKES PROVIDING LOW LEVEL CONVERGENCE. IR SATELLITE IMAGERY
SHOWING A WEAK BAROCLINIC LEAF DEVELOPING ACROSS THE OHIO VALLEY
EARLY THIS MORNING. AS THIS FEATURE TRANSLATES NORTHEAST TODAY IT
WILL ACT TO ENHANCE MID LEVEL FRONTOGENESIS AND DEFORMATION ACROSS
OUR REGION...AIDING IN MORE WIDESPREAD SHOWERS. PWAT VALUES ARE
AROUND 1.8 INCHES ON AVERAGE WITH AMPLE MOISTURE IN PLACE.
GIVEN THE QUALITY MOISTURE AND SUFFICIENT FORCING FOR ASCENT COMING
TOGETHER...HAVE RAISED POPS TO CATEGORICAL FOR THE BULK OF THE AREA
THIS MORNING WITH THE EXCEPTION OF A FEW COUNTIES ALONG THE CANADIAN
BORDER WHERE SHOWERS SHOULD BE A LITTLE LESS FREQUENT. IN GENERAL
THE MOST PERSISTENT RAIN AND HIGHEST AMOUNTS SHOULD FOCUS FROM THE
WESTERN SOUTHERN TIER TO THE FINGER LAKES AND SOUTHERN TUG HILL
REGION WITH LESSER AMOUNTS NEAR THE INTERNATIONAL BORDER. ENOUGH
INSTABILITY WILL REMAIN TO KEEP A FEW EMBEDDED THUNDERSTORMS AS
WELL...ALTHOUGH COVERAGE WILL REMAIN WIDELY SCATTERED. A FEW STORMS
MAY PRODUCE LOCALLY HEAVY RAINFALL...BUT THIS RISK SHOULD REMAIN
VERY ISOLATED AT BEST.
THIS AFTERNOON THE AFOREMENTIONED DYNAMICS AND BAROCLINIC LEAF WILL
SHIFT SLOWLY SOUTH AND EAST AND TAKE THE STEADIER SHOWERS WITH IT.
EXPECT A DRYING TREND FOR THE AFTERNOON FROM NORTHWEST TO SOUTHEAST
WITH AREAS ALONG AND NORTH OF THE NYS THRUWAY EVENTUALLY BECOMING
MAINLY DRY WITH A FEW BREAKS OF SUNSHINE POSSIBLE LATE. SHOWERS WILL
BE SLOWER TO END ACROSS THE SOUTHERN TIER AND ACROSS THE HIGHER
TERRAIN EAST OF LAKE ONTARIO.
THE EXTENSIVE CLOUD COVER WILL KEEP TEMPERATURES LOWER TODAY
ALTHOUGH IT WILL STILL BE VERY MUGGY. EXPECT HIGHS IN THE UPPER 70S
ON THE LAKE PLAINS AND LOWER TO MID 70S ACROSS THE HIGHER TERRAIN.
THE WARM SPOT SHOULD BE THE SAINT LAWRENCE VALLEY WHERE SHOWERS AND
THICKER CLOUD COVER WILL EXIT THE EARLIEST.
TONIGHT SHOWERS ACROSS THE SOUTHERN TIER AND CENTRAL NY WILL
CONTINUE TO SLOWLY DIMINISH. ENOUGH INSTABILITY MAY DEVELOP IN THE
WAKE OF THIS MAIN RAIN AREA TO ALLOW SCATTERED THUNDERSTORMS TO FORM
DURING THE LATE AFTERNOON AND EARLY EVENING ACROSS THE NIAGARA
PENINSULA. IF THEY MATERIALIZE...A FEW MAY MAKE IT INTO AREAS JUST
NORTH OF BUFFALO THIS EVENING. SCATTERED STORMS MAY ALSO FORM OVER
SOUTHEAST ONTARIO AND CROSS THE SAINT LAWRENCE INTO THE NORTH
COUNTRY THIS EVENING. OTHERWISE EXPECT SOME PARTIAL CLEARING
OVERNIGHT ON THE LAKE PLAINS. ACROSS THE HIGHER TERRAIN LOW LEVEL
MOISTURE AND WEAK UPSLOPE FLOW AND CONVERGENCE WILL LIKELY SUPPORT
EXPANDING LOW CLOUD COVER. EXPECT LOWS IN THE MID TO UPPER 60S ON
THE LAKE PLAINS AND LOWER TO MID 60S IN THE SOUTHERN TIER AND NORTH
COUNTRY.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
A WARM AND STICKY AIRMASS WILL REMAIN ACROSS THE REGION ON
MONDAY...WITH MOST OF THE FORECAST AREA EXPERIENCING MAINLY DRY
CONDITIONS. HOWEVER THERE WILL BE THE CHANCE FOR SCATTERED SHOWERS
AND THUNDERSTORMS IN THE AFTERNOON AND EVENING...MAINLY ACROSS THE
INTERIOR SOUTHERN TIER WHERE THE BEST INSTABILITY WILL RESIDE. CAPE
VALUES BY LATER IN THE AFTERNOON ACROSS THIS REGION WILL RUN IN THE
1000-1500 J/KG RANGE WITH LI`S POSSIBLY AS LOW AS -4. HOWEVER WITH
WEAK 0-6KM BULK SHEAR (~20KTS) AND LACK OF A GOOD SURFACE TRIGGER
(ASIDE FROM A POSSIBLE LAKE BREEZE)...NOT EXPECTING ANY
THUNDERSTORMS TO REACH SEVERE LIMITS. INSTABILITY LOOKS LOWER ACROSS
THE REMAINDER OF THE AREA...AND THUS CONVECTIVE CHANCES LOOK MUCH
LOWER AS WELL. TEMPERATURES WILL AGAIN BE ON THE WARM SIDE WITH
HIGHS IN THE UPPER 70S TO LOWER 80S.
WITH THE LOSS OF DAYTIME HEATING MONDAY NIGHT MOST OF THE DIURNALLY
DRIVEN CONVECTION WILL DIMINISH IN COVERAGE...ALTHOUGH A FEW STORMS
MAY CONTINUE LATE INTO THE EVENING...ESPECIALLY ACROSS PORTIONS OF
THE SOUTHERN TIER. AT THE SAME TIME A COLD FRONT OVER THE UPPER
GREAT LAKES WILL BE ADVANCING TOWARD THE REGION AND BE LOCATED WEST
OF NEW YORK STATE BY TUESDAY MORNING. THAT SAID...MOST OF THE NIGHT
LOOKS TO REMAIN DRY...WITH PRECIP CHANCES STARTING TO INCREASE A BIT
ACROSS WESTERN NEW YORK TOWARD TUESDAY MORNING. ANOTHER MILD
NIGHT CAN BE EXPECTED WITH LOWS IN THE MID TO UPPER 60S FOR MOST
LOCATIONS THANKS TO DEEP SOUTHERLY FLOW OUT AHEAD OF THE APPROACHING
COLD FRONT.
LATEST GUIDANCE PACKAGE HAS THE COLD FRONT NOW MOVING A BIT SLOWER
THAN IN PREVIOUS RUNS. THIS IS MOST LIKELY DUE TO MOST OF THE MODELS
NOW COMING INTO AGREEMENT ON THE DEVELOPMENT OF LOW PRESSURE
SOMEWHERE IN THE OHIO VALLEY ALONG THE FRONT AND THEN TRACKING IT
NORTHEAST ALONG THE BOUNDARY WHICH WOULD SLOW IT DOWN A LITTLE.
THAT SAID...IT NOW APPEARS IT WILL TAKE THE BULK OF THE DAY TUESDAY
FOR THE COLD FRONT TO SWEEP ACROSS THE REGION WITH SHOWERS AN
THUNDERSTORMS LIKELY...WITH LOWER CHANCE POPS BY LATER IN THE DAY
ACROSS WESTERN NEW YORK. HIGH PRECIPITABLE WATER VALUES OF 1.7"-1.9"
TUESDAY AFTERNOON OFFER THE RISK OF HEAVY DOWNPOURS WITH ANY
THUNDERSTORM. SBCAPES OVER 1000 J/KG COMBINED WITH LIFTED INDEX
VALUES AT -4C TO -5C ALSO POINT TO THE POSSIBILITY OF STORMS. THE
MAIN DIFFERENCES FROM MONDAY ARE THAT 0-6KM BULK SHEAR VALUES LOOK
TO BE IN THE 40-45KT RANGE...AND ALSO HAVE THE SURFACE COLD FRONT
CROSSING THE FORECAST AREA WHICH WILL SERVE AS THE FOCAL POINT FOR
STORMS TO FIRE ALONG. ALL THIS SAID...LOOKS AS THOUGH THERE COULD BE
SOME STRONG STORMS...WITH A FEW STORMS POSSIBLY REACHING SEVERE
LIMITS. MAIN THREATS APPEAR TO BE GUSTY WINDS ASSOCIATED WITH BOWING
LINE SEGMENTS AND MARGINALLY SEVERE HAIL. ANOTHER WARM DAY ON TAP
WITH HIGHS IN THE UPPER 70S TO LOWER 80S.
THE COLD FRONT WILL SLIDE SOUTH AND EAST OF THE FORECAST AREA
TUESDAY EVENING...TAKING THE SHOWERS AND STORMS WITH IT. ALTHOUGH A
FEW SHOWERS WILL STILL BE POSSIBLE DURING THE EVENING ACROSS EASTERN
AREAS...BUT EVEN HERE THINGS WILL DRY OUT LATER TUESDAY NIGHT AS
SURFACE HIGH PRESSURE STARTS TO BUILD EAST ACROSS NEW YORK STATE.
LOWS WILL BE GENERALLY IN THE UPPER 50S TO LOWER 60S.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
UPPER LEVEL RIDGING AND SURFACE HIGH PRESSURE WILL BUILD ACROSS THE
REGION WEDNESDAY AND THURSDAY BRINGING IN DRIER AIR AND TEMPERATURES
THAT WILL STILL AVERAGE AT OR JUST A BIT ABOVE NORMAL FOR EARLY
SEPTEMBER. HIGH PRESSURE WILL THEN SLIDE OFF THE NEW ENGLAND COAST
BY FRIDAY. THIS WILL PROVIDE MAINLY DRY CONDITIONS THROUGH
MIDWEEK...BEFORE THE NEXT FRONTAL SYSTEM APPROACHES FOR LATE IN THE
WEEK AND EARLY WEEKEND. TEMPERATURES WILL BE A BIT ABOVE SEASONAL
NORMALS WITH HIGHS IN THE UPPER 70S TO LOW 80S AND LOWS IN THE LOWER
60S.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
A STEADY AREA OF LIGHT RAIN WILL CONTINUE TO MOVE SLOWLY EAST ACROSS
THE SOUTHERN TIER...FINGER LAKES...AND CENTRAL NY THROUGH MIDDAY.
CIGS/VSBY WILL REMAIN VFR IN MANY AREAS...ALTHOUGH A FEW POCKETS OF
MODERATE RAIN WILL PRODUCE MVFR VSBY AT TIMES. EXPECT POCKETS OF
MVFR/IFR CIGS TO ALSO BECOME A LITTLE MORE COMMON BY MID MORNING
ACROSS THE HIGHER TERRAIN OF THE SOUTHERN TIER AND FINGER LAKES. THE
LOWER ELEVATIONS ON THE LAKE PLAINS SHOULD STAY MAINLY VFR DUE IN
PART TO SSW DOWNSLOPE FLOW.
THE STEADIER SHOWERS WILL DIMINISH FROM NORTHWEST TO SOUTHEAST
DURING THE LATE MORNING TO EARLY AFTERNOON. EXPECT CIGS/VSBY TO
IMPROVE TO MAINLY VFR EXCEPT IN ANY HEAVIER SHOWERS AND WIDELY
SCATTERED THUNDERSTORMS THAT DEVELOP WITH DAYTIME HEATING THIS
AFTERNOON. BY MID AFTERNOON THESE SHOULD BE CONFINED TO THE SOUTHERN
TIER AND CENTRAL NY WITH THE REMAINDER OF THE AREA DRY.
TONIGHT ANY SHOWERS AND SCATTERED THUNDER ACROSS THE SOUTHERN TIER
WILL DIMINISH DURING THE EVENING. MAINLY VFR DURING THE EVENING WILL
GIVE WAY TO INCREASING AMOUNTS OF IFR IN LOW STRATUS OVERNIGHT WITH
EXTENSIVE LOW LEVEL MOISTURE FIELDS. EXPECT STRATUS TO FORM FIRST
ACROSS HIGHER TERRAIN...BUT MAY SPREAD TO THE LOWER ELEVATIONS OF
WESTERN NY AS WELL AFTER ABOUT 09Z. AREAS OF FOG AND IFR VSBY ARE
LIKELY ACROSS THE HIGHER TERRAIN OF THE SOUTHERN TIER AND FINGER
LAKES AS WELL WHERE THE LOW STRATUS INTERSECTS THE HILLS.
OUTLOOK...
MONDAY...VFR/MVFR IN SCATTERED SHOWERS AND THUNDERSTORMS.
TUESDAY...SHOWERS AND THUNDERSTORMS LIKELY WITH ASSOCIATED BRIEF
MVFR/IFR. SOME STORMS MAY BE STRONG.
WEDNESDAY AND THURSDAY...VFR.
&&
.MARINE...
MODERATE SOUTHERLIES WILL CONTINUE TO PRODUCE MARGINAL SMALL CRAFT
ADVISORY CONDITIONS AT THE NORTHEAST END OF LAKE ONTARIO FROM GALLOO
ISLAND TO CAPE VINCENT THROUGH EARLY TO MID MORNING BEFORE
DIMINISHING. LOW PRESSURE WILL MOVE ACROSS SOUTHERN QUEBEC TODAY
WITH WINDS BECOMING MORE SOUTHWEST ON THE LOWER LAKES. THIS WILL
ALLOW WINDS TO INCREASE SOMEWHAT ON LAKE ERIE...WITH MARGINAL SMALL
CRAFT ADVISORY CONDITIONS FROM MID TO LATE MORNING THROUGH MID TO
LATE AFTERNOON.
THE PRESSURE GRADIENT RELAXES ACROSS THE LOWER LAKES TONIGHT AS LOW
PRESSURE DISSIPATES OVER SOUTHEAST QUEBEC. THIS WILL ALLOW WINDS AND
WAVES TO SUBSIDE.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR LEZ040-
041.
SMALL CRAFT ADVISORY UNTIL 11 AM EDT THIS MORNING FOR
LOZ045.
&&
$$
SYNOPSIS...HITCHCOCK
NEAR TERM...HITCHCOCK
SHORT TERM...JM
LONG TERM...JM/WCH
AVIATION...HITCHCOCK
MARINE...HITCHCOCK
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
729 AM EDT SUN AUG 31 2014
.SYNOPSIS...
STRENGTHENING BERMUDA HIGH PRESSURE OFFSHORE WILL BRING SUMMERTIME
HEAT AND HUMIDITY THROUGH THE LABOR DAY WEEKEND WITH A FEW SHOWERS
AND THUNDERSTORMS POSSIBLE. A WEAK COLD FRONT WILL APPROACH FROM THE
NORTH LATE NEXT WEEK...BUT WILL LIKELY STALL BEFORE REACHING THE
AREA. BERMUDA HIGH PRESSURE AND A PIEDMONT TROUGH WILL REMAIN THE
DOMINANT FEATURES INTO NEXT WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM SUNDAY...SURFACE HIGH PRESSURE COVERS MUCH OF THE
WESTERN AND CENTRAL ATLANTIC OCEAN. THE UPPER LEVEL RIDGE IS
CENTERED JUST OFF THE CAROLINA COAST AND SHOULD KEEP ANY SYNOPTIC
IMPULSES DEFLECTED AWAY TO OUR NORTH AND WEST. 850 MB TEMPERATURES
AROUND +18C THIS AFTERNOON SHOULD RESULT IN HIGH TEMPERATURES IN THE
MID 90S FROM MARION AND FLORENCE WESTWARD INTO DARLINGTON COUNTY.
ONSHORE WINDS CLOSER TO THE COAST SHOULD KEEP TEMPERATURES A LITTLE
COOLER...GENERALLY IN THE UPPER 80S TO LOWER 90S.
ALTHOUGH THERE IS CONSIDERABLE DRY AIR ALOFT DUE TO THE UPPER RIDGE
(COLUMN PRECIP WATER VALUES ARE ONLY 1.5 INCHES) VERY RICH MOISTURE
EXISTS IN THE LOWEST LEVELS OF THE ATMOSPHERE. DEWPOINTS IN THE MID
70S THIS MORNING WILL FORTUNATELY MIX DOWN TO NEAR 70 THIS AFTERNOON
INLAND...BUT THAT WILL STILL BE ENOUGH TO PUSH HEAT INDICES TO
100-103 DEGREES ACROSS MOST OF OUR FORECAST AREA. THIS MOISTURE MAY
ALSO FUEL WIDELY SCATTERED SHOWERS NEAR THIS COAST LATER THIS
MORNING...PROBABLY BECOMING LESSER IN COVERAGE THIS AFTERNOON AS
DRIER AIR MIXES DOWNWARD. FORECAST POPS RANGE FROM 20-30 PERCENT...
VIRTUALLY ALL EAST OF I-95 AND HIGHEST IN A STRIPE ACROSS LELAND TO
BURGAW AS CONSISTENTLY INDICATED BY HOURLY HRRR MODEL RUNS THROUGH
THE NIGHT.
ANY LINGERING DAYTIME CUMULUS SHOULD QUICKLY DIE AWAY THIS
EVENING... WITH ONLY A LITTLE PATCHY FOG OR LOW STRATUS EXPECTED TO
DEVELOP OVERNIGHT. LOWS SHOULD FALL INTO THE LOWER 70S FOR MOST
LOCALES...A FEW DEGREES WARMER NEAR THE BEACHES.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 3 AM SUNDAY...BERMUDA HIGH AND STRENGTHENING PIEDMONT TROUGH
WILL BE THE MAIN SURFACE FEATURES THROUGH THE PERIOD. ALOFT A FLAT
MID LEVEL RIDGE WILL EXTEND ACROSS MUCH OF THE SOUTHERN CONUS. DEEP
WESTERLY FLOW IN THE MID LEVELS WILL PUSH TROPICAL MOISTURE
EXPANDING NORTH FROM THE WESTERN GULF OF MEXICO OVER THE REGION MON
AND TUE. INCREASING MOISTURE ALOFT ALONG WITH LOW LEVEL MOISTURE
ADVECTION AROUND WEST SIDE OF BERMUDA HIGH WILL PUSH PRECIPITABLE
WATER VALUES OVER 2 INCHES FOR MUCH OF THE PERIOD.
FLAT MID LEVEL PATTERN MEANS LITTLE TO NO FORCING ALOFT WILL BE
PRESENT. HOWEVER THE COMBINATION OF LOW LEVEL MOISTURE AND SURFACE
HEATING WILL PUSH ML CAPE VALUES TO 1K-2K J/KG FOR MON AND OVER 2K
J/KG ON TUE. CONVECTION WILL INITIALLY BE SLOW TO DEVELOP BUT ONCE
SEA BREEZE AND PIEDMONT TROUGH TAKE SHAPE SHOWERS AND THUNDERSTORMS
SHOULD START POPPING UP. WILL MAINTAIN CHC POP FOR EACH AFTERNOON
BUT WITH SLIGHTLY HIGHER VALUES ON TUE GIVEN SLIGHTLY HIGHER CAPE
VALUES.
TEMPERATURES WILL RUN ABOVE CLIMO THROUGH THE PERIOD. HIGHS WILL
RANGE FROM UPPER 80S ALONG THE IMMEDIATE COAST TO MID 90S INLAND.
LOWS WILL BE IN THE LOW TO MID 70S.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 3 AM SUNDAY...BERMUDA HIGH AND PIEDMONT TROUGH ALONG WITH
ELONGATED MID LEVEL RIDGE WILL REMAIN THE SIGNIFICANT FEATURES
THROUGH THE PERIOD. A COUPLE COLD FRONTS WILL TRY AND MAKE A RUN TO
THE AREA DURING THE NEXT WEEK BUT THEY ARE LIKELY TO STALL AND WASH
OUT JUST NORTH OF THE FORECAST AREA. THE SURFACE AND MID LEVEL
PATTERNS ARE NOT ONES THAT GENERALLY SUPPORT FRONTS MOVING INTO AND
SOUTH OF THE CAPE FEAR REGION. PRECIPITABLE WATER VALUES WILL REMAIN
AROUND 2 INCHES THROUGH THE END OF THE WEEK. DIURNAL HEATING AND
SOUTHWEST FLOW WILL RESULT IN ML CAPE VALUES ABOVE 2K J/KG FOR MUCH
OF THE PERIOD. WEAK GRADIENT WILL ALLOW SEA BREEZE DEVELOPMENT AND
PIEDMONT TROUGH SHOULD BE WELL DEFINED. TYPICAL SUMMER PATTERN WITH
NEAR CLIMO PWATS AND TEMPERATURES NEAR TO SLIGHTLY ABOVE CLIMO
SUGGEST POP WILL BE NEAR CLIMO FOR MUCH OF THE PERIOD...30 PERCENT.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
AS OF 12Z...IFR TEMPO LIFR IN BR/FG OCCURRING AT KFLO THIS
MORNING. KLBT IS VFR. TEMPO MVFR CIGS ARE OCCURRING AT KCRE/KMYR.
ISOLATED LIGHT SHOWERS ARE MOVING N ACROSS THE NEAR SHORE WATERS.
BR/FG SHOULD BURN OFF AROUND 14Z AT KFLO. VFR IS THEN EXPECTED AT
BOTH KFLO/KLBT INTO THIS EVENING. TEMPO MVFR CIGS/SHOWERS WILL
REMAIN POSSIBLE AT THE COASTAL TERMINALS UNTIL THE SEA SHIFTS
FURTHER INLAND MID-LATE MORNING. BEST CONFIDENCE OF A TEMPO SHOWER
IS AT KILM. VFR IS THEN EXPECTED AFTERWARDS AT THE COASTAL
TERMINALS INTO THIS EVENING. THIS AFTERNOON THE BEST SHOWER
POTENTIAL WILL BE BETWEEN THE INLAND AND COASTAL TERMINALS. SE-S
WINDS WILL INCREASE TO 10-20 KT AT THE COASTAL TERMINALS AND 5 TO
10 KT AT KFLO/KLBT LATER THIS MORNING.
WINDS SLOWLY DECREASE THIS EVENING...BECOMING LGT S-SW THIS
EVENING AND OVERNIGHT. BEST BR/FG POTENTIAL WILL BE THE INLAND TERMINALS
OVERNIGHT...WITH IFR VSBYS/LIFR CIGS LIKELY KFLO/KLBT BY 08Z.
EXTENDED OUTLOOK...INCREASING CHANCES FOR AFTN SHOWERS/TSTMS MONDAY
THROUGH THURSDAY WITH BRIEF AND LOCALIZED PERIODS OF MVFR POSSIBLE.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM SUNDAY...SURFACE HIGH PRESSURE COVERS MOST OF THE
WESTERN AND CENTRAL ATLANTIC OCEAN. THIS SHOULD PRODUCE A
SOUTH-SOUTHEAST WIND TODAY...VEERING MORE SOUTHWESTERLY TONIGHT.
SEAS CURRENTLY AROUND 2 FEET MAY OCCASIONALLY REACH 3 FEET IN A
COMBINATION OF SOUTHEASTERLY SWELL AND LOCAL WIND WAVES...WITH ANY
SCATTERED MORNING SHOWERS EXPECTED TO DISSIPATE BY EARLY AFTERNOON.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 3 AM SUNDAY...BERMUDA HIGH AND PIEDMONT TROUGH WILL MAINTAIN
SOUTHWEST FLOW OVER THE WATERS THROUGH THE PERIOD. SPEEDS 10 KT OR
LESS WILL INCREASE TO A SOLID 15 KT EACH AFTERNOON AND EVENING AS
THE PIEDMONT TROUGH STRENGTHENS. SEAS IN THE 2 TO 3 FT RANGE.
LONG TERM /WEDNESDAY THROUGH THURSDAY/...
AS OF 3 AM SUNDAY...MINIMAL CHANGE FOR THE LONG TERM PERIOD. BERMUDA
HIGH REMAINS IN PLACE AS DOES THE PIEDMONT TROUGH. LATE IN THE
PERIOD A WEAKENING COLD FRONT WILL APPROACH FROM THE NORTH BUT IS
EXPECTED TO STALL BEFORE REACHING THE AREA. SOUTHWEST FLOW AROUND 10
KT WILL INCREASE TO A SOLID 15 KT EACH AFTERNOON AND EVENING. SEAS
WILL RUN 2 TO 3 FT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...TRA
SHORT TERM...III
LONG TERM...III
AVIATION...MRR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
633 AM EDT SUN AUG 31 2014
.SYNOPSIS...
STRENGTHENING BERMUDA HIGH PRESSURE OFFSHORE WILL BRING SUMMERTIME
HEAT AND HUMIDITY THROUGH THE LABOR DAY WEEKEND WITH A FEW SHOWERS
AND THUNDERSTORMS POSSIBLE. A WEAK COLD FRONT WILL APPROACH FROM THE
NORTH LATE NEXT WEEK...BUT WILL LIKELY STALL BEFORE REACHING THE
AREA. BERMUDA HIGH PRESSURE AND A PIEDMONT TROUGH WILL REMAIN THE
DOMINANT FEATURES INTO NEXT WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM SUNDAY...SURFACE HIGH PRESSURE COVERS MUCH OF THE
WESTERN AND CENTRAL ATLANTIC OCEAN. THE UPPER LEVEL RIDGE IS
CENTERED JUST OFF THE CAROLINA COAST AND SHOULD KEEP ANY SYNOPTIC
IMPULSES DEFLECTED AWAY TO OUR NORTH AND WEST. 850 MB TEMPERATURES
AROUND +18C THIS AFTERNOON SHOULD RESULT IN HIGH TEMPERATURES IN THE
MID 90S FROM MARION AND FLORENCE WESTWARD INTO DARLINGTON COUNTY.
ONSHORE WINDS CLOSER TO THE COAST SHOULD KEEP TEMPERATURES A LITTLE
COOLER...GENERALLY IN THE UPPER 80S TO LOWER 90S.
ALTHOUGH THERE IS CONSIDERABLE DRY AIR ALOFT DUE TO THE UPPER RIDGE
(COLUMN PRECIP WATER VALUES ARE ONLY 1.5 INCHES) VERY RICH MOISTURE
EXISTS IN THE LOWEST LEVELS OF THE ATMOSPHERE. DEWPOINTS IN THE MID
70S THIS MORNING WILL FORTUNATELY MIX DOWN TO NEAR 70 THIS AFTERNOON
INLAND...BUT THAT WILL STILL BE ENOUGH TO PUSH HEAT INDICES TO
100-103 DEGREES ACROSS MOST OF OUR FORECAST AREA. THIS MOISTURE MAY
ALSO FUEL WIDELY SCATTERED SHOWERS NEAR THIS COAST LATER THIS
MORNING...PROBABLY BECOMING LESSER IN COVERAGE THIS AFTERNOON AS
DRIER AIR MIXES DOWNWARD. FORECAST POPS RANGE FROM 20-30 PERCENT...
VIRTUALLY ALL EAST OF I-95 AND HIGHEST IN A STRIPE ACROSS LELAND TO
BURGAW AS CONSISTENTLY INDICATED BY HOURLY HRRR MODEL RUNS THROUGH
THE NIGHT.
ANY LINGERING DAYTIME CUMULUS SHOULD QUICKLY DIE AWAY THIS
EVENING... WITH ONLY A LITTLE PATCHY FOG OR LOW STRATUS EXPECTED TO
DEVELOP OVERNIGHT. LOWS SHOULD FALL INTO THE LOWER 70S FOR MOST
LOCALES...A FEW DEGREES WARMER NEAR THE BEACHES.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 3 AM SUNDAY...BERMUDA HIGH AND STRENGTHENING PIEDMONT TROUGH
WILL BE THE MAIN SURFACE FEATURES THROUGH THE PERIOD. ALOFT A FLAT
MID LEVEL RIDGE WILL EXTEND ACROSS MUCH OF THE SOUTHERN CONUS. DEEP
WESTERLY FLOW IN THE MID LEVELS WILL PUSH TROPICAL MOISTURE
EXPANDING NORTH FROM THE WESTERN GULF OF MEXICO OVER THE REGION MON
AND TUE. INCREASING MOISTURE ALOFT ALONG WITH LOW LEVEL MOISTURE
ADVECTION AROUND WEST SIDE OF BERMUDA HIGH WILL PUSH PRECIPITABLE
WATER VALUES OVER 2 INCHES FOR MUCH OF THE PERIOD.
FLAT MID LEVEL PATTERN MEANS LITTLE TO NO FORCING ALOFT WILL BE
PRESENT. HOWEVER THE COMBINATION OF LOW LEVEL MOISTURE AND SURFACE
HEATING WILL PUSH ML CAPE VALUES TO 1K-2K J/KG FOR MON AND OVER 2K
J/KG ON TUE. CONVECTION WILL INITIALLY BE SLOW TO DEVELOP BUT ONCE
SEA BREEZE AND PIEDMONT TROUGH TAKE SHAPE SHOWERS AND THUNDERSTORMS
SHOULD START POPPING UP. WILL MAINTAIN CHC POP FOR EACH AFTERNOON
BUT WITH SLIGHTLY HIGHER VALUES ON TUE GIVEN SLIGHTLY HIGHER CAPE
VALUES.
TEMPERATURES WILL RUN ABOVE CLIMO THROUGH THE PERIOD. HIGHS WILL
RANGE FROM UPPER 80S ALONG THE IMMEDIATE COAST TO MID 90S INLAND.
LOWS WILL BE IN THE LOW TO MID 70S.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 3 AM SUNDAY...BERMUDA HIGH AND PIEDMONT TROUGH ALONG WITH
ELONGATED MID LEVEL RIDGE WILL REMAIN THE SIGNIFICANT FEATURES
THROUGH THE PERIOD. A COUPLE COLD FRONTS WILL TRY AND MAKE A RUN TO
THE AREA DURING THE NEXT WEEK BUT THEY ARE LIKELY TO STALL AND WASH
OUT JUST NORTH OF THE FORECAST AREA. THE SURFACE AND MID LEVEL
PATTERNS ARE NOT ONES THAT GENERALLY SUPPORT FRONTS MOVING INTO AND
SOUTH OF THE CAPE FEAR REGION. PRECIPITABLE WATER VALUES WILL REMAIN
AROUND 2 INCHES THROUGH THE END OF THE WEEK. DIURNAL HEATING AND
SOUTHWEST FLOW WILL RESULT IN ML CAPE VALUES ABOVE 2K J/KG FOR MUCH
OF THE PERIOD. WEAK GRADIENT WILL ALLOW SEA BREEZE DEVELOPMENT AND
PIEDMONT TROUGH SHOULD BE WELL DEFINED. TYPICAL SUMMER PATTERN WITH
NEAR CLIMO PWATS AND TEMPERATURES NEAR TO SLIGHTLY ABOVE CLIMO
SUGGEST POP WILL BE NEAR CLIMO FOR MUCH OF THE PERIOD...30 PERCENT.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AS OF 06Z...STILL EXPECT MVFR/IFR CIGS TO DEVELOP EARLY THIS MORNING
WITH THE BEST CHANCES FOR IFR INLAND AT KLBT/KFLO. HAVE BACKED OFF
THE FOG A BIT GIVEN THE INCREASING DEBRIS CLOUDS SPREADING INTO OUR
AREA. WOULD NOT RULE OUT TEMPO IFR VSBYS INLAND...BUT MVFR SEEMS
MORE LIKELY ATTM. EXPECT PERIODS OF MVFR CIGS ALONG THE COAST
BEGINNING AROUND DAYBREAK...WITH THE POTENTIAL FOR SOME ISOLATED
SHOWERS MOVING ONSHORE AS WELL. THE HRRR MODEL SHOWS A FEW SHOWERS
SKIRTING THE COAST THIS MORNING...SO WILL MAINTAIN VCSH FOR
KILM/KCRE/KMYR. THE MVFR CIGS MAY LINGER THROUGH MUCH OF THE
MORNING...BUT CONDITIONS WILL IMPROVE TO VFR BY MIDDAY AND PERSIST
THROUGH THE REST OF THE PERIOD. WINDS WILL BE SOUTH 6-10 KT DURING
THE DAY...POSSIBLY A BIT HIGHER ALONG THE COAST. COULD SEE SOME
ISOLATED SHOWERS ALONG THE SEABREEZE FONT IN THE AFTN...BUT
CONFIDENCE IN TIMING/LOCATION IS TOO LOW TO MENTION IN THE TAFS.
EXTENDED OUTLOOK...INCREASING CHANCES FOR AFTN SHOWERS/TSTMS MONDAY
THROUGH THURSDAY WITH BRIEF AND LOCALIZED PERIODS OF MVFR POSSIBLE.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM SUNDAY...SURFACE HIGH PRESSURE COVERS MOST OF THE
WESTERN AND CENTRAL ATLANTIC OCEAN. THIS SHOULD PRODUCE A
SOUTH-SOUTHEAST WIND TODAY...VEERING MORE SOUTHWESTERLY TONIGHT.
SEAS CURRENTLY AROUND 2 FEET MAY OCCASIONALLY REACH 3 FEET IN A
COMBINATION OF SOUTHEASTERLY SWELL AND LOCAL WIND WAVES...WITH ANY
SCATTERED MORNING SHOWERS EXPECTED TO DISSIPATE BY EARLY AFTERNOON.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 3 AM SUNDAY...BERMUDA HIGH AND PIEDMONT TROUGH WILL MAINTAIN
SOUTHWEST FLOW OVER THE WATERS THROUGH THE PERIOD. SPEEDS 10 KT OR
LESS WILL INCREASE TO A SOLID 15 KT EACH AFTERNOON AND EVENING AS
THE PIEDMONT TROUGH STRENGTHENS. SEAS IN THE 2 TO 3 FT RANGE.
LONG TERM /WEDNESDAY THROUGH THURSDAY/...
AS OF 3 AM SUNDAY...MINIMAL CHANGE FOR THE LONG TERM PERIOD. BERMUDA
HIGH REMAINS IN PLACE AS DOES THE PIEDMONT TROUGH. LATE IN THE
PERIOD A WEAKENING COLD FRONT WILL APPROACH FROM THE NORTH BUT IS
EXPECTED TO STALL BEFORE REACHING THE AREA. SOUTHWEST FLOW AROUND 10
KT WILL INCREASE TO A SOLID 15 KT EACH AFTERNOON AND EVENING. SEAS
WILL RUN 2 TO 3 FT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...TRA
SHORT TERM...III
LONG TERM...III
AVIATION...BJR/TRA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
837 AM CDT SUN AUG 31 2014
.UPDATE...
ISSUED AT 824 AM CDT SUN AUG 31 2014
SHOWER ACTIVITY WITH A FEW WEAK THUNDERSTORMS CONTINUES MAINLY
ALONG AND EAST OF A LINE FROM JAMESTOWN TO HARVEY TO BOTTINEAU.
HAVE ADJUSTED POPS ACCORDINGLY FOR THIS...AND HAVE KEPT SOME LOW
POPS IN THE FAR SOUTHWEST AS SOME WEAK SHOWERS START TO DEVELOP
AND MOVE INTO THAT AREA. HAVE ALSO EXPANDED PATCHY FOG COVERAGE
FOR THE MORNING AS VISIBILITY HAS DROPPED OVER A VARIETY OF
LOCATIONS IN WESTERN NORTH DAKOTA. UPDATES HAVE BEEN SENT.
UPDATE ISSUED AT 633 AM CDT SUN AUG 31 2014
STILL GETTING SOME THUNDERSTORM REDEVELOPMENT ACROSS EAST CENTRAL
NORTH DAKOTA IN STUTSMAN COUNTY. APPEARS THIS WILL TRACK EAST FOR
THE NEXT FEW HOURS. AREAS OF FOG SPREADING ACROSS THE FAR NORTH.
THIS WILL LAST THROUGH MID MORNING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 358 AM CDT SUN AUG 31 2014
FOCUS IN THE SHORT TERM WILL BE ON THE EXITING RAINFALL THROUGH
THIS MORNING AND THE CHANCES FOR RAIN LATER TODAY.
THE HRRR MODEL HAS DONE A DECENT JOB OF FORECASTING PRECIPITATION
THROUGH THE NIGHT AND EARLY THIS MORNING AND POPS MIMIC THE 05 UTC
HRRR PRECIPITATION AS IT PROGRESSES NORTHEAST. MOST ALL HEAVY RAIN
HAS PUSHED EAST INTO EASTERN NORTH DAKOTA...HOWEVER A VERY THIN BAND
OF SHOWERS IS SLOWLY MOVING EAST ACROSS WESTERN NORTH DAKOTA. AS OF
0730 UTC THE BAND DROPPED HEAVY RAIN AT THE DICKINSON AIRPORT. DO
NOT EXPECT THIS BAND...AT LEAST THE HEAVY RAIN ASSOCIATED WITH
IT...TO LAST MUCH LONGER INTO THE MORNING HOURS.
LOOKING FORWARD TO THIS AFTERNOON AND TONIGHT MODELS AGREE ON A
BROAD TROUGH SETTING UP OVER THE NORTHERN PLAINS TODAY WITH A WEAK
SHORT WAVE MOVING THROUGH IN THE AFTERNOON AND NIGHT. THE 00 UTC
MODELS ARE HAVING A DIFFICULT TIME NAILING DOWN WHERE THE
PRECIPITATION WILL FALL EXACTLY...HOWEVER ONLY LIGHT TO MODERATE
SHOWERS ARE EXPECTED. AT THE MOST EXPECTING A SOME SCATTERED SHOWERS
AND A FEW RUMBLES OF THUNDER.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 358 AM CDT SUN AUG 31 2014
THE EXTENDED BEGINS WITH A COOL CYCLONIC FLOW ALOFT ACROSS THE
NORTHERN PLAINS MONDAY INTO TUESDAY. THIS SHOULD AT LEAST SUPPORT
SOME WIDELY SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS. HIGHS
MONDAY AND TUESDAY WILL BE A BIT COOL IN THE UPPER 60S TO LOWER
70S. BY WEDNESDAY THE FLOW ALOFT BECOMES MORE ZONAL AS THE
IN BETWEEN SHORTWAVE TROUGHS. BY THURSDAY THE GFS/ECMWF/GEM BRING
THE NEXT SHORTWAVE TROUGH INTO THE NORTHERN PLAINS WHICH IS
PRETTY CONSISTENT WITH THE PAST FEW MODEL RUNS. THE ECMWF/GEM ARE A
BIT MORE ROBUST IN QPF FORECAST FOR NORTH DAKOTA. LIKED THE
ALLBLEND VERSION OF POPS FOR WEDNESDAY NIGHT AT 30 POPS FOR NOW.
AFTER THURSDAY THE FLOW ALOFT BECOMES SEPARATED BETWEEN A NORTHERN
AND SOUTHERN STREAM FLOW WITH THE GFS MORE PRONOUNCED IN THE FLOW
SEPARATION AROUND A CUTOFF LOW OFF THE WEST COAST. THE BASIC
RESULT WILL BE A QUIET PERIOD FRIDAY INTO SATURDAY AS THE FLOW
MERGES ALOFT OVER THE NORTHERN PLAINS RESULTING IN WEAK SUDSIDENCE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 633 AM CDT SUN AUG 31 2014
FRONTAL BOUNDARY IS MOVING EAST ACROSS THE REGION THIS MORNING. ONLY
KJMS IS AHEAD OF THE FRONT AND BY 18Z THE FRONT SHOULD BE PAST KJMS.
LOW CLOUDS WILL STICK AROUND THROUGH THE MORNING AT KJMS...KBIS...
AND KMOT PROVIDING IFR TO MVFR CONDITIONS. EXPECT CONDITIONS TO
IMPROVE EARLY THIS AFTERNOON FROM WEST TO EAST. SHOWERS AND
THUNDERSTORMS WILL ALSO BE POSSIBLE THROUGH THE 12Z TAF
PERIOD...HOWEVER SCATTERED IN NATURE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JJS
SHORT TERM...MM
LONG TERM...WAA
AVIATION...MM
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
710 AM CDT SUN AUG 31 2014
.UPDATE...
ISSUED AT 705 AM CDT SUN AUG 31 2014
CONVECTION ASSOCIATED WITH MID/UPPER LEVEL CIRCULATION MOVING
NORTHEAST 30KTS...WITH REDEVELOPMENT SOUTHWEST OF THE DEVILS LAKE
BASIN UNDER 700 MB CAA. AREA HAS GRADUALLY SLOWED DURING THE PAST
SEVERAL HOURS AS UPPER CIRCULATION APPEARS TO BE INTENSIFYING.
REDEVELOPMENT APPEARS AIDED BY 850MB MOIST TRANSPORT AND 0-6KM
BULK SHEAR OF 40KTS. LATEST HRRR AND 03Z HOPWRF SUPPORT THESE
TRENDS THROUGH 18Z. HAVE TWEAKED POPS/WX/WINDS BASED ON CURRENT
CONDITIONS AND HIGH-RES MODEL FCSTS.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 330 AM CDT SUN AUG 31 2014
FOR THE NEXT 6 TO 12 HOURS THE MAIN CONCERN IS THE CONVECTION AND
RISK FOR SEVERE. AS OF 08Z A LINE OF TSRA EXTENDED FROM
KDVL...KS32 TO KGWR MOVG EAST 35 KTS. THIS LINE IS MOVING INTO AN
AREA OF INCREASINGLY STABLE AIR AND APPEARS TO BE OUTRUNNING THE
LOWER LEVEL FORCING. THE NAM12 AND GFS40 HAD BEEN INCREASING THE
BULK 0-6KM SHEAR TO NEAR 50KTS IN THE DEVILS LAKE BASIN...WHICH
DOES NOT YET APPEAR TO BE THE CASE. HAVE TRIED TO TIME THE TSRA
ACROSS THE CWFA THIS FIRST 12 HOURS BLENDING INHERITED FCST AND
HRRR/NAM/WRF MODEL MOVEMENT.
THE FIRST WAVE ASSOCIATED WITH CONVECTION MOVES EAST BY
18Z...WITH SECOND FAST WAVE MOVING INTO WY AS OF 08Z. AS THE UPPER
WAVES ARE PROGRESSIVE AND THE SYNOPTIC SCALE MODELS ARE IN FAIR
AGREEMENT WITH THE HIGH-RES MODELS...HAVE TRENDED THE BULK OF THE
TSRA/RASH OVER THE EASTERN HALF CWFA BY 00Z. MAY HAVE HELD ON TO
POPS TOO LONG POST 18Z...BUT THIS IS DIFFICULT TO ASCERTAIN ATTM.
THE FCST PRESENCE OF THE LOW LEVEL BOUNDARY AND INSTABILITY 18Z-
00Z ARGUES FOR HOLDING ONTO POPS.
SECOND SHORT WAVE FORECAST TO MOVE ACROSS THE SOUTHERN HALF OF
THE FA 00Z TO 06Z MONDAY SO HAVE HELD ON TO CHC POPS THROUGH 06Z
THEN ENDED RAIN RISK FOR MONDAY. HIGH TEMPERATURES TODAY WILL BE
HIGHLY DEPENDENT ON THE CLOUD COVER...THICKNESSES ARE HIGH ENOUGH
OVER THE SOUTH TO SUPPORT UPPER 70S TO LOWER 80S. HAVE USED THE
LOCAL BIAS CORRECTED TEMPERATURE MODEL FOR TODAY - TUESDAY AS IT
SEEMS TO HAVE SUPERIOR SKILL OF LATE.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 330 AM CDT SUN AUG 31 2014
FLOW ALOFT TURNS FLAT WEST-NORTHWEST BEHIND SECOND WAVE BUT
HEIGHTS DO NOT FALL APPRECIABLY. THE NEXT SHORTWAVE AND ASSOCIATED
SURFACE REFLECTION IMPACTS THE SOUTHERN CWFA MONDAY NIGHT. MODELS
SUGGEST NEXT WAVE FOR TUESDAY FOCUSED MORE ALONG AND NORTH OF THE
HIGHWAY 2 CORRIDOR FOR TUESDAY AFTERNOON AND EVENING...WITH ONLY
CHC POPS.
WEDNESDAY THROUGH SATURDAY...THE NEXT UPPER TROUGH WILL MOVE INTO
THE NORTHERN ROCKIES AT THE START OF THE PERIOD...THEN MOVING OFF
INTO MANITOBA BY THURSDAY. THE SFC LOW WILL MOVE BY TO OUR SOUTH AND
WE SHOULD SEE PLENTY OF PRECIP WITH A BOUNDARY NEARBY...ALTHOUGH THE
MODELS DIFFER ON EXACT TIMING AND PLACEMENT OF THE LOW. WILL
CONTINUE TO KEEP FAIRLY HIGH POPS FOR WEDNESDAY NIGHT AND SOME
LINGERING IN THE EST INTO THURSDAY AS A COLD FRONT COMES THROUGH.
SFC HIGH PRESSURE BUILDING IN FOR THE END OF THE PERIOD WILL BRING
DRY CONDITIONS AND COOLER TEMPERATURES. THE ECMWF AND GFS START TO
DIVERGE BY SATURDAY...SO KEPT ALLBLEND POPS FOR THE TIME BEING.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 636 AM CDT SUN AUG 31 2014
TYPICAL MIXTURE OF VFR/MVFR/IFR CIGS FOUND IN THE PRESENCE OF TSRA
AND SHRA AS AREA OF CONVECTION MOVES NORTHEAST 30 TO 35 KTS. SFC
LOW AND ASSOC WNDSHFT FCST TO MOVE TO KGFK...KFAR LINE 19Z TO
20Z...REACHING KBJI AROUND 010200Z. AFTER INITIAL CONVECTION MOVES
NORTHEAST TAF SITES...EXPCT VFR CIGS AND VSBY.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...EWENS
SHORT TERM...EWENS
LONG TERM...JR/EWENS
AVIATION...EWENS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
639 AM CDT SUN AUG 31 2014
.UPDATE...
ISSUED AT 633 AM CDT SUN AUG 31 2014
STILL GETTING SOME THUNDERSTORM REDEVLOPMENT ACROSS EAST CENTRAL
NORTH DAKOTA IN STUTSMAN COUNTY. APPEARS THIS WILL TRACK EAST FOR
THE NEXT FEW HOURS. AREAS OF FOG SPEADING ACROSS THE FAR NORTH.
THIS WILL LAST THROUGH MID MORNING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 358 AM CDT SUN AUG 31 2014
FOCUS IN THE SHORT TERM WILL BE ON THE EXITING RAINFALL THROUGH
THIS MORNING AND THE CHANCES FOR RAIN LATER TODAY.
THE HRRR MODEL HAS DONE A DECENT JOB OF FORECASTING PRECIPITATION
THROUGH THE NIGHT AND EARLY THIS MORNING AND POPS MIMIC THE 05 UTC
HRRR PRECIPITATION AS IT PROGRESSES NORTHEAST. MOST ALL HEAVY RAIN
HAS PUSHED EAST INTO EASTERN NORTH DAKOTA...HOWEVER A VERY THIN BAND
OF SHOWERS IS SLOWLY MOVING EAST ACROSS WESTERN NORTH DAKOTA. AS OF
0730 UTC THE BAND DROPPED HEAVY RAIN AT THE DICKINSON AIRPORT. DO
NOT EXPECT THIS BAND...AT LEAST THE HEAVY RAIN ASSOCIATED WITH
IT...TO LAST MUCH LONGER INTO THE MORNING HOURS.
LOOKING FORWARD TO THIS AFTERNOON AND TONIGHT MODELS AGREE ON A
BROAD TROUGH SETTING UP OVER THE NORTHERN PLAINS TODAY WITH A WEAK
SHORT WAVE MOVING THROUGH IN THE AFTERNOON AND NIGHT. THE 00 UTC
MODELS ARE HAVING A DIFFICULT TIME NAILING DOWN WHERE THE
PRECIPITATION WILL FALL EXACTLY...HOWEVER ONLY LIGHT TO MODERATE
SHOWERS ARE EXPECTED. AT THE MOST EXPECTING A SOME SCATTERED SHOWERS
AND A FEW RUMBLES OF THUNDER.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 358 AM CDT SUN AUG 31 2014
THE EXTENDED BEGINS WITH A COOL CYCLONIC FLOW ALOFT ACROSS THE
NORTHERN PLAINS MONDAY INTO TUESDAY. THIS SHOULD AT LEAST SUPPORT
SOME WIDELY SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS. HIGHS
MONDAY AND TUESDAY WILL BE A BIT COOL IN THE UPPER 60S TO LOWER
70S. BY WEDNESDAY THE FLOW ALOFT BECOMES MORE ZONAL AS THE
IN BETWEEN SHORTWAVE TROUGHS. BY THURSDAY THE GFS/ECMWF/GEM BRING
THE NEXT SHORTWAVE TROUGH INTO THE NORTHERN PLAINS WHICH IS
PRETTY CONSISTENT WITH THE PAST FEW MODEL RUNS. THE ECMWF/GEM ARE A
BIT MORE ROBUST IN QPF FORECAST FOR NORTH DAKOTA. LIKED THE
ALLBLEND VERSION OF POPS FOR WEDNESDAY NIGHT AT 30 POPS FOR NOW.
AFTER THURSDAY THE FLOW ALOFT BECOMES SEPARATED BETWEEN A NORTHERN
AND SOUTHERN STREAM FLOW WITH THE GFS MORE PRONOUNCED IN THE FLOW
SEPARATION AROUND A CUTOFF LOW OFF THE WEST COAST. THE BASIC
RESULT WILL BE A QUIET PERIOD FRIDAY INTO SATURDAY AS THE FLOW
MERGES ALOFT OVER THE NORTHERN PLAINS RESULTING IN WEAK SUDSIDENCE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 633 AM CDT SUN AUG 31 2014
FRONTAL BOUNDARY IS MOVING EAST ACROSS THE REGION THIS MORNING. ONLY
KJMS IS AHEAD OF THE FRONT AND BY 18Z THE FRONT SHOULD BE PAST KJMS.
LOW CLOUDS WILL STICK AROUND THROUGH THE MORNING AT KJMS...KBIS...
AND KMOT PROVIDING IFR TO MVFR CONDITIONS. EXPECT CONDITIONS TO
IMPROVE EARLY THIS AFTERNOON FROM WEST TO EAST. SHOWERS AND
THUNDERSTORMS WILL ALSO BE POSSIBLE THROUGH THE 12Z TAF
PERIOD...HOWEVER SCATTERED IN NATURE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...WAA
SHORT TERM...MM
LONG TERM...WAA
AVIATION...MM
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1116 AM EDT SUN AUG 31 2014
.SYNOPSIS...
DEEP MOISTURE AND UPPER LEVEL DISTURBANCES PROVIDE ROUNDS OF
SHOWERS AND STORMS TODAY. WEAK FRONT CROSSES TUESDAY WITH SHOWERS
AND STORMS.
&&
.NEAR TERM /THROUGH TONIGHT/...
SENT A QUICK UPDATE TO ADJUST POPS ACCORDING WITH LATEST DOPPLER
RADAR AND HIGH RESOLUTION MODELS. REMOVED THUNDER AT LEAST THROUGH
18Z AS THERE IS NO SIGN OF LIGHTNING UNDER AREAS OF STRATIFORM
RAIN. EMBEDDED SHOWERS COULD BECOME THUNDERSTORMS THIS AFTERNOON
ACROSS CENTRAL WV. THE HEAVIEST RAINFALL COULD REACH 0.5 INCHES
PER HOURS. WILL KEEP MONITORING THE RAINFALL RATES THROUGH THIS
AFTERNOON.
PREVIOUS DISCUSSION BELOW...
UPDATE...
NOW HAVE EVIDENCE OF THE STRATUS DECK SHOWING UP OVER SOUTHEAST
OHIO AND THE TRI STATE AREA WITH FEW/SCT SHOWING UP IN THE OBS
BELOW 2500FT. REWORKED THE POPS GIVEN THE RADAR TRENDS...AND
CONTINUE WITH THE QUIETER PERIOD BETWEEN 12Z AND 16Z. RAINFALL
AMOUNTS OVER THE LAST 3 HOURS ARE IN THE 0.2 TO 0.3 INCH RANGE IN
THE HEAVIER AMOUNTS.
PREVIOUS DISCUSSION...
THROUGH THE EARLY AFTERNOON/18Z TIME FRAME TODAY...LEANED HEAVILY ON
THE HRRR MODEL GIVEN THAT IT HAD INITIALIZED VERY WELL. TYPICALLY
LIKE THE OUTPUT OF THIS MODEL WHEN THAT HAPPENS. ALSO...SINCE THE
NAM MATCHED UP FAIRLY WELL...DEFORMATION AND FRONTOGENESIS PROGS
PROVED VALUABLE IN THE PATTERN OF THE POP CONSTRUCTION THIS MORNING.
THIS HELPED TO ADD SOME DEFINITION TO THE PREVIOUS
FORECAST...PARTICULARLY OVER THE LOWLANDS SOUTH/EAST OF THE OHIO
RIVER.
AXIS OF DEEP MOISTURE DEPARTS TONIGHT...ALTHOUGH MAY STILL BE
HANGING ON IN THE MOUNTAINS BY 12Z MONDAY.
TEMPERATURES COME DOWN SIGNIFICANTLY FOR TODAY IN THE PERIODIC RAIN.
MAY NOT COME OUT OF THE 70S OVER SOUTHEAST OHIO. SOUTHERN MOUNTAIN
LOCATIONS IN THE EASTERN PORTION OF THE CWA COULD END UP WARMER THAN
THE OHIO RIVER SITES. THE MAV GUIDANCE HAS BEEN HANDS DOWN BETTER
THAN THE OTHERS AND LEANED ON THIS...BUT ALWAYS A LITTLE HESITANT
IN A DIFFERENT ATMOSPHERE.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
MODELS AGREE OUR AREA WILL BE BETWEEN TWO SIGNIFICANT SYSTEMS ON
MONDAY. WHILE DYNAMICS WILL BE AT A MINIMUM...A WARM AND HUMID
AIRMASS WILL CONTINUE FOR A THREAT OF SCATTERED AFTERNOON STORMS
MONDAY...AND MORE SUNSHINE WILL LEAD TO HIGH TEMPERATURES IN THE MID
TO UPPER 80S. WITH LOSS OF HEATING...ANY CONVECTION WILL DISSIPATE
QUICKLY EARLY MONDAY EVENING. IT WILL REMAIN MOSTLY PRECIP FREE
MONDAY NIGHT BEFORE THE NEXT SYSTEM IN THE FORM OF ANOTHER UPPER
TROUGH AND ASSOCIATED COOL FRONT AFFECT US TUESDAY. MODELS HAVE THE
UPPER TROUGH PROGRESSING EASTWARD ACROSS OUR AREA TUESDAY AND EARLY
TUESDAY NIGHT WITH A BAND OF SHOWERS AND STORMS. SO HIGH POPS
PROGRESSING FROM NORTHWEST TO SOUTHEAST TUESDAY INTO EARLY TUESDAY
NIGHT ARE IN ORDER. WHILE THE UPPER TROUGH EXITS TUESDAY NIGHT...THE
COOL FRONT WILL LOSE DEFINITION AS IT CROSSES THE AREA...AND
GRADUALLY BE REPLACED BY WEAK HIGH PRESSURE LATER TUESDAY NIGHT AND
WEDNESDAY. HEIGHTS RISE MODESTLY BEHIND THE UPPER TROUGH...BUT
MODELS STILL INDICATE ENOUGH MOISTURE AND INSTABILITY IN THE FAR
SOUTH FOR A SHOWER OR TWO TO CONTINUE INTO WEDNESDAY. LOOK FOR HIGH
TEMPERATURES TO STAY IN THE 80S FOR TUESDAY AND WEDNESDAY...BUT WITH
SOME DRIER AIR FILTERING INTO THE NORTH TUESDAY NIGHT AND
WEDNESDAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
LONG TERM PERIOD CAN GENERALLY BE CHARACTERIZED BY ZONAL FLOW ALOFT.
LEANED WPC FOR THE MOST PART WITH A FEW TWEAKS HERE AND THERE. WARM
AND MUGGY CONDITIONS WILL CONTINUE THROUGH THE PERIOD...WITH NO HEAT
WAVES OR ABNORMALLY COOL SPELLS IN SIGHT. A COLD FRONT WILL PUSH
ACROSS TUE NIGHT WITH ANOTHER FRONT APPROACHING SAT NIGHT...WITH
SUBSEQUENT HIGHER POPS DURING THOSE PERIODS. IN BETWEEN...THURSDAY
AND FRIDAY LOOK MOSTLY SUNNY TO PERHAPS PARTLY CLOUDY WITH ONLY
MINIMAL CHANCES FOR PRECIP EACH DAY.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS WILL PREVAIL ACROSS MOST SITES THROUGH 18Z. THE
EXCEPTION WILL BE MVFR UNDER LIGHT RAIN POSSIBLE AT HTS...TO MOVE
OVER CRW BY 18-20Z. CONVECTION WILL INCREASE IN INTENSITY ACROSS
CENTRAL WV THIS AFTERNOON.
INCLUDED TSRA FOR CRW...CKB...AND BKW...AND VCTS/CB FOR THE REST
OF SITES AFTER 18Z.
EXPECT AND EXTENSIVE LOW STRATUS DECK TO SET UP THIS EVENING AS
THE DEEPER MOISTURE PUSHES NORTHEASTWARD. AS THOSE CEILINGS COME
DOWN...FEEL THE VISIBILITIES CAN COME DOWN AS WELL WITH THE RECENT
RAIN. NO LIFR FOG DUE TO LIGHT WINDS OVERNIGHT.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z MONDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING AND EXTENT OF TSRA THIS AFTERNOON MAY
VARY. EXTEND OF POST RAIN AND SUBSIDENCE OF LOW STRATUS COULD VARY
FROM SITE TO SITE.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
EDT 1HRLY 10 11 12 13 14 15 16 17 18 19 20 21
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H M M M M M M M M M
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H H H H H H H H M M
PKB CONSISTENCY M H H H H H H H M M M M
CKB CONSISTENCY M H H H H H M M M M M M
AFTER 12Z MONDAY...
IFR IN DENSE EARLY MORNING VALLEY FOG EARLY NEXT WEEK. IFR IN
SHOWERS AND STORMS POSSIBLE WITH THE COLD FRONT TUESDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...JMV/26
NEAR TERM...ARJ/26
SHORT TERM...JMV
LONG TERM...50
AVIATION...26
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
640 AM EDT SUN AUG 31 2014
.SYNOPSIS...
DEEP MOISTURE AND UPPER LEVEL DISTURBANCES PROVIDE ROUNDS OF
SHOWERS AND STORMS TODAY. WEAK FRONT CROSSES TUESDAY WITH SHOWERS
AND STORMS.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...
NOW HAVE EVIDENCE OF THE STRATUS DECK SHOWING UP OVER SOUTHEAST
OHIO AND THE TRI STATE AREA WITH FEW/SCT SHOWING UP IN THE OBS
BELOW 2500FT. REWORKED THE POPS GIVEN THE RADAR TRENDS...AND
CONTINUE WITH THE QUIETER PERIOD BETWEEN 12Z AND 16Z. RAINFALL
AMOUNTS OVER THE LAST 3 HOURS ARE IN THE 0.2 TO 0.3 INCH RANGE IN
THE HEAVIER AMOUNTS.
PREVIOUS DISCUSSION...
THROUGH THE EARLY AFTERNOON/18Z TIME FRAME TODAY...LEANED HEAVILY ON
THE HRRR MODEL GIVEN THAT IT HAD INITIALIZED VERY WELL. TYPICALLY
LIKE THE OUTPUT OF THIS MODEL WHEN THAT HAPPENS. ALSO...SINCE THE
NAM MATCHED UP FAIRLY WELL...DEFORMATION AND FRONTOGENESIS PROGS
PROVED VALUABLE IN THE PATTERN OF THE POP CONSTRUCTION THIS MORNING.
THIS HELPED TO ADD SOME DEFINITION TO THE PREVIOUS
FORECAST...PARTICULARLY OVER THE LOWLANDS SOUTH/EAST OF THE OHIO
RIVER.
AXIS OF DEEP MOISTURE DEPARTS TONIGHT...ALTHOUGH MAY STILL BE
HANGING ON IN THE MOUNTAINS BY 12Z MONDAY.
TEMPERATURES COME DOWN SIGNIFICANTLY FOR TODAY IN THE PERIODIC RAIN.
MAY NOT COME OUT OF THE 70S OVER SOUTHEAST OHIO. SOUTHERN MOUNTAIN
LOCATIONS IN THE EASTERN PORTION OF THE CWA COULD END UP WARMER THAN
THE OHIO RIVER SITES. THE MAV GUIDANCE HAS BEEN HANDS DOWN BETTER
THAN THE OTHERS AND LEANED ON THIS...BUT ALWAYS A LITTLE HESITANT
IN A DIFFERENT ATMOSPHERE.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
MODELS AGREE OUR AREA WILL BE BETWEEN TWO SIGNIFICANT SYSTEMS ON
MONDAY. WHILE DYNAMICS WILL BE AT A MINIMUM...A WARM AND HUMID
AIRMASS WILL CONTINUE FOR A THREAT OF SCATTERED AFTERNOON STORMS
MONDAY...AND MORE SUNSHINE WILL LEAD TO HIGH TEMPERATURES IN THE MID
TO UPPER 80S. WITH LOSS OF HEATING...ANY CONVECTION WILL DISSIPATE
QUICKLY EARLY MONDAY EVENING. IT WILL REMAIN MOSTLY PRECIP FREE
MONDAY NIGHT BEFORE THE NEXT SYSTEM IN THE FORM OF ANOTHER UPPER
TROUGH AND ASSOCIATED COOL FRONT AFFECT US TUESDAY. MODELS HAVE THE
UPPER TROUGH PROGRESSING EASTWARD ACROSS OUR AREA TUESDAY AND EARLY
TUESDAY NIGHT WITH A BAND OF SHOWERS AND STORMS. SO HIGH POPS
PROGRESSING FROM NORTHWEST TO SOUTHEAST TUESDAY INTO EARLY TUESDAY
NIGHT ARE IN ORDER. WHILE THE UPPER TROUGH EXITS TUESDAY NIGHT...THE
COOL FRONT WILL LOSE DEFINITION AS IT CROSSES THE AREA...AND
GRADUALLY BE REPLACED BY WEAK HIGH PRESSURE LATER TUESDAY NIGHT AND
WEDNESDAY. HEIGHTS RISE MODESTLY BEHIND THE UPPER TROUGH...BUT
MODELS STILL INDICATE ENOUGH MOISTURE AND INSTABILITY IN THE FAR
SOUTH FOR A SHOWER OR TWO TO CONTINUE INTO WEDNESDAY. LOOK FOR HIGH
TEMPERATURES TO STAY IN THE 80S FOR TUESDAY AND WEDNESDAY...BUT WITH
SOME DRIER AIR FILTERING INTO THE NORTH TUESDAY NIGHT AND
WEDNESDAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
LONG TERM PERIOD CAN GENERALLY BE CHARACTERIZED BY ZONAL FLOW ALOFT.
LEANED WPC FOR THE MOST PART WITH A FEW TWEAKS HERE AND THERE. WARM
AND MUGGY CONDITIONS WILL CONTINUE THROUGH THE PERIOD...WITH NO HEAT
WAVES OR ABNORMALLY COOL SPELLS IN SIGHT. A COLD FRONT WILL PUSH
ACROSS TUE NIGHT WITH ANOTHER FRONT APPROACHING SAT NIGHT...WITH
SUBSEQUENT HIGHER POPS DURING THOSE PERIODS. IN BETWEEN...THURSDAY
AND FRIDAY LOOK MOSTLY SUNNY TO PERHAPS PARTLY CLOUDY WITH ONLY
MINIMAL CHANCES FOR PRECIP EACH DAY.
&&
.AVIATION /10Z SUNDAY THROUGH THURSDAY/...
NOW SEEING THE DEVELOPMENT OF THE EXPECTED MVFR/IFR STRATUS DECK
BACK IN OHIO TOWARDS THE NORTHERN PANHANDLE. WILL BE WATCHING UNI
AND THEN THE RIVER TERMINALS OF PKB AND HTS TO DO THE SAME AND
CARRY THIS IN THE TAFS THIS MORNING.
AFTER A LULL IN THE CONVECTION THIS MORNING...EXPECT IT TO PICK UP
THIS AFTERNOON. CARRYING VCTS/CB IN THE TAFS RIGHT NOW AS THE
BANDS OF SHOWERS AND STORMS PASS THROUGH THE AREA. BEST CHANCE FOR
THE CONVECTION IS WEST OF THE MOUNTAINS AND IN THE OHIO VALLEY.
THIS DOES NOT MEAN THUNDER CHANCES ARE RELEGATED TO THESE AREAS
HOWEVER.
EXPECT AND EXTENSIVE LOW STRATUS DECK TO SET UP THIS EVENING AS
THE DEEPER MOISTURE PUSHES NORTHEASTWARD. AS THOSE CEILINGS COME
DOWN...FEEL THE VISIBILITIES CAN COME DOWN AS WELL WITH THE RECENT
RAIN. NO LIFR FOG DUE TO LIGHT WINDS OVERNIGHT.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z MONDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING AND EXTENT OF TSRA IS IN QUESTION.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 11 12 13 14 15 16 17 18 19 20 21 22
EDT 1HRLY 07 08 09 10 11 12 13 14 15 16 17 18
CRW CONSISTENCY L L L M H H H M M M H M
HTS CONSISTENCY L L L M H M M M M M M M
BKW CONSISTENCY M M M H H H H H H H H H
EKN CONSISTENCY L L L M H H H H H H H H
PKB CONSISTENCY L L L L M M H H H H H M
CKB CONSISTENCY L L L L M M H H H M M M
AFTER 12Z MONDAY...
IFR IN DENSE EARLY MORNING VALLEY FOG EARLY NEXT WEEK. IFR IN
SHOWERS AND STORMS POSSIBLE WITH THE COLD FRONT TUESDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...JMV/26
NEAR TERM...26
SHORT TERM...JMV
LONG TERM...50
AVIATION...26
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
655 AM EDT SUN AUG 31 2014
.SYNOPSIS...
A WARM AND HUMID SOUTHWEST FLOW WILL KEEP THE CHANCES FOR RAIN IN
THE FORECAST THROUGH THE LABOR DAY HOLIDAY. A COLD FRONT WILL
BRING A BREAK IN THE HUMIDITY FOR MID WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE RADAR BECOMING MORE ACTIVE WITH SCATTERED SHOWERS AND
THUNDERSTORMS MOVING THROUGH WRN PA...MAKING SLOW PROGRESS TOWARD
MY FCST AREA.
THE HRRR SHOWS THE RAIN CURRENTLY FROM KENTUCKY INTO SOUTHERN OHIO
CONTINUING TO MARCH NORTHEAST THROUGH MORNING WITH MOST OF MY
WESTERN ZONES GETTING WET BY ABOUT 6-7AM...AND MUCH OF THE REST OF
MY FCST AREA COVERED WITH SHOWERS AND THUNDERSTORMS BY MID DAY.
THIS AFTERNOON WE COULD ALSO SEE A SEVERE THREAT DEVELOP FOR MY
SERN ZONES. MODELS ARE COOKING UP A FAIR AMOUNT OF CAPE OVER
EASTERN AREAS HINTING THAT THE THE CLOUDS WILL BE LESS EXTENSIVE
ALLOWING FOR MORE IN THE WAY OF SOLAR HEATING. FORECAST MID LEVEL
LAPSE RATES ARE WEAK BUT SHEAR WILL INCREASE WHICH COULD AID IN
ORGANIZING STORM DEVELOPMENT.
MODELS ALSO PROG A WEAK LOW LEVEL CONVERGENCE ZONE...PERHAPS THE
REMNANTS OF THE OLD WARM FRONT WHERE ENHANCED LOW LEVEL
SHEAR...EHI`S PROGGED 1-3(M^2/S^2) COULD HELP A STORM OR TWO TAKE
ON SOME SPIN. WITH LOW LCLS EXPECTED IN THE VERY TROPICAL
AIRMASS...HAVE TO STAY AWARE OF THE POTENTIAL FOR AN ISOLATED
TORNADO. AS IT STANDS RIGHT NOW...THE SEVERE THREAT WILL BE VERY
DEPENDENT ON GETTING THE SUN TO COME OUT AND FIRST COOK UP THE
CAPES.
WITH AN ANOMALOUSLY STRONG LOW LEVEL JET AND PURE TROPICAL
AIR...ANOTHER THREAT WILL BE LOCALLY HEAVY RAIN IN SOME OF THE
THUNDERSTORMS. IT HAS BEEN DRY SO NO HEADLINES ARE PLANNED...BUT
WILL OPT FOR SOME ENHANCED WORDING IN THE FORECAST AND HWO
PRODUCT.
HIGHS WILL NOT BE TERRIBLY HIGH...IN THE MID 70S TO MID 80S FROM
NW TO SE...BUT DEWPOINTS WELL UP IN THE 60S TO LOWER 70S WILL
BRING ONE OF THE MORE UNCOMFORTABLY HUMID DAYS WE`VE SEEN THIS
SUMMER.
IT`S HARD TO PIN DOWN WHAT WILL OCCUR OVERNIGHT WITH REGARD TO
CONVECTION. ECMWF/NAM/GFS ALL PAINT DIFFERENT SCENARIOS. THE
NAM/SREF REPRESENT THE WETTEST SOLUTIONS WITH SOME SORT OF MESO
LOW TRACKING ACROSS SOUTHERN PA. THE GFS/GEFS ARGUE FOR SMALLER
CHANCES OF RAIN WITH MOST OF THE AREA SEEING WEAK LOW LEVEL
RIDGING DEVELOP IN THE WAKE OF TODAY`S EVENTS. THE ECMWF IS THE
DRIEST OF ALL. RIGHT NOW WE HAVE LIKELY POPS OVER THE SOUTH AND
CHANCE OVER THE NORTH. UNLESS I SEE SOMETHING COMPELLING...WILL
PROBABLY NOT CHANGE IT MUCH GIVEN THE EXPECTATIONS OF LITTLE OR
NO REAL FOCUSING MECHANISM.
ANOTHER WARM MUGGY NIGHT IS IN STORE AS THE AIRMASS WILL REMAIN
VIRTUALLY UNCHANGED.
&&
.SHORT TERM /MONDAY/...
AT THIS TIME I AM HOLDING OUT HOPE OF A DRIER LABOR DAY...BUT
CANNOT DROP THE MENTION OF RAIN ALTOGETHER. SREF/GEFS BOTH SHOW
THE ANOMALOUS PWAT PLUME SLIDING EAST WITH DRYING TAKING PLACE
LOCALLY. SHORT RANGE OPERATIONAL GUIDANCE HINTS AT WEAK SHORTWAVE
RIDGING AND RISING UPPER HEIGHTS...SO I TRENDED POPS DOWN DURING
THE DAY WITH THE THINKING BEING THAT MOST AREAS WILL HAVE A DRY
AFTERNOON AND EVENING FOR THE LAST OF THE TRADITIONAL SUMMER`S
COOKOUTS.
OVERALL IT WILL NOT FEEL SIGNIFICANTLY DRIER HOWEVER AS
TEMPERATURES WILL ONCE AGAIN RISE INTO THE 70S AND 80S WITH
DEWPOINTS REMAINING TROPICAL IN THE 60S AND LOWER 70S.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
STILL PRETTY GOOD AGREEMENT IN A COLD FRONT SWINGING THROUGH THE
STATE LATE TUESDAY. THIS SHOULD PROVIDE THE BEST CHANCE OF RAIN
IN THE EXTENDED BEFORE HIGH PRESSURE BUILDS IN FOR
MIDWEEK...BRINGING A FEW DAYS OF MILD AND DRY WEATHER. THE NEXT
CHANCE FOR RAIN LOOKS LIKE IT WILL NOT BE UNTIL LATER IN THE WEEK
WHEN A MORE HUMID FLOW WILL DEVELOP AROUND THE HIGH MOVING OFF THE
COAST. AT THIS POINT A COLD FRONT LOOKS LIKELY FOR SATURDAY
FOLLOWED BY A COOLER AIRMASS FOR NEXT WEEKEND.
THIS UPCOMING WEEK WILL BE ONE OF THE RARE EXTENDED PERIODS OF
WARMER THAN NORMAL TEMPERATURES WE HAVE SEEN THIS SUMMER. HIGH
TEMPERATURES WILL CLIMB TO ALMOST 90 ACROSS THE SOUTH AND EAST ON
TUESDAY AHEAD OF THE FRONTAL PASSAGE. THEN AN UPPER RIDGE WILL
BUILD OVER THE EASTERN US FOR THE SECOND HALF OF THE
WEEK...KEEPING HIGH TEMPERATURES AT OR SLIGHTLY ABOVE SEASONAL
NORMALS FOR EARLY SEPTEMBER.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
MAIN AREAS THAT STILL HAVE CIGS IN THE 1500 RANGE IS
IPT...MDT...AND LNS. MOST OF THE LOWER CIGS OUT OF THE
UNV...AOO...AND JST. SHOWERS IN THE BFD AREA AT 12Z.
RATHER FAST MOVING BOW ECHO WILL MOVE JUST NORTH OF
UNV.
WILL ADJUST THE 12Z TAFS.
ANYWAY...THE MAIN ISSUE NOW IS THE LARGE AREA OF SHOWERS
AND THUNDERSTORMS JUST MOVING INTO OUR AREA FROM PIT.
BEEN UPDATING FCST AS NEEDED.
OUTLOOK...
MON...AM FOG POSS...ESP W MTNS. ISOLD PM TSRA IMPACTS
POSS.
TUE...SCT PM TSRA IMPACTS POSS.
WED...PATCHY AM FOG POSS.
THU...PATCHY AM FOG POSS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...LA CORTE
AVIATION...MARTIN
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1039 AM CDT SUN AUG 31 2014
.UPDATE...REST OF TODAY
SOMEWHAT DIFFICULT FORECAST SHAPING UP FOR TODAY WITH A FEW
UNCERTAINTIES. FAIRLY POTENT SHORTWAVE TROUGH CROSSING WYOMING AT
THIS TIME. SFC COLD FRONT IT MAKING ITS WAY THROUGH THE EASTERN
CWA AND IS ALMOST AT THE SD/MN BORDER. AREA OF RAIN MOVING
NORTHEAST ACROSS SOUTH CENTRAL SD. MADE A FEW CHANGES TO THE
FORECAST FOR TODAY BASED ON CURRENT MODEL AND RADAR TRENDS. FIRST
OFF...SEVERE THREAT LOOKS TO BE EAST OF THE CWA TODAY AND LATEST
DAY ONE SEVERE OUTLOOK HAS SHIFTED EAST. FRONTAL PASSAGE SPEED
LIKELY PUTS BEST SEVERE POTENTIAL FROM MINNESOTA THROUGH IOWA AND
INTO NEBRASKA. HAVING SAID THAT THOUGH...STILL EXPECTING
ADDITIONAL SHOWER AND STORM DEVELOPMENT ACROSS WESTERN/CENTRAL SD
LATER THIS AFTERNOON...THEN SPREADING EAST INTO THE EVENING.
MODELS PICKING UP ON THIS...AND HRRR ACTUALLY HAVING A GOOD
REPRESENTATION OF CURRENT CONDITIONS AND MAY BE LATCHING ONTO
SOMETHING FOR LATER TODAY. BASICALLY...IT WOULD APPEAR MUCH OF THE
CWA IS QUIET TODAY...ESPECIALLY THE NORTHEAST. BUT BY THIS
AFTERNOON AND EVENING COULD SEE AN INCREASE IN SHOWER AND STORM
COVERAGE. ADJUSTED POPS ACCORDINGLY BUT STILL SOME UNCERTAINTY
HERE. NEED TO WATCH AREA OF RAIN MOVING TOWARDS PIERRE TO SEE IF
IT HOLDS TOGETHER OR EXPANDS. CONCERNING TODAYS TEMPS...ANOTHER
GREY AREA AS ABUNDANT MID LEVEL CLOUDS STREAMING INTO THE REGION
MAY KEEP TEMPS DOWN A FEW DEGREES. ALSO DEALING WITH A STRATUS
DECK OVER THE NORTHERN CWA IN WHICH ITS RESIDENT TIME OVER THE
AREA IS QUESTIONABLE. FURTHER ADJUSTMENTS TO POPS/TEMPS LIKELY
NEEDED THROUGHOUT THE DAY.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...THROUGH TUESDAY
WARM ADVECTION/LOW LEVEL JET LINE OF STORMS PUSHING RAPIDLY TO THE
EAST/NORTHEAST. THE SURFACE LOW IS POSITIONED BACK TOWARDS THE MO
RIVER...AND THE UPPER TROF AXIS IS POSITIONED BACK IN WY. WHILE
THE SURFACE LOW/TROF IS EXPECTED TO PUSH INTO THE FAR EASTERN
CWA...COOLER AIR ALOFT WILL HELP DESTABILIZE THE ATMOSPHERE ACROSS
THE REGION. THE FAR EASTERN CWA WILL CONTINUE TO SEE A FAVORABLE
SHEAR PROFILE FOR SEVERE WEATHER...AND THE REST OF THE CWA WILL
REMAIN CONVECTIVELY UNSTABLE. LOSS TO DAYTIME HEATING WILL REMOVE
THE THREAT OF STORMS...HOWEVER CLOUDS AND LIGHT SHOWERS MAY
PERSIST AS THE UPPER TROF REMAINS OVERHEAD. A SECONDARY SHORTWAVE
MOVES IN MONDAY EVENING...WITH ANOTHER ROUND OF CONVECTION.
AS FOR TEMPERATURES...LOOK FOR HIGHS IN THE 70S BOTH TODAY AND
MONDAY. TUESDAY WILL SEE WARMER READINGS UNDER A WARM ADVECTION
REGIME.
.LONG TERM...TUESDAY NIGHT THROUGH SATURDAY
THE MODELS AGREE WELL IN THE LONG TERM WITH KEEPING IT MAINLY DRY
ALONG WITH A COOL DOWN. THE PERIOD BEGINS WITH AN UPPER LOW PRESSURE
TROUGH DROPPING INTO THE PACIFIC NORTHWEST ON TUESDAY NIGHT. THIS
THEN TRACKS ALONG THE CANADIAN BORDER INTO THURSDAY. AT THE
SURFACE...A LOW PRESSURE AREA AND COOL FRONT SWEEP FROM NORTHWEST
TO SOUTHEAST ACROSS OUR REGION FROM TUESDAY NIGHT INTO THURSDAY.
THUS...WARMER AIR AND SUNSHINE IN ADVANCE OF THIS WILL BRING ABOVE
NORMAL TEMPERATURES TO THE CWA FOR WEDNESDAY WITH HIGHS IN THE 80S
TO AROUND 90 DEGREES IN THE SOUTHWEST CWA. AS THE SURFACE LOW PRESSURE
AREA/COOL FRONT PUSH ACROSS THE REGION FOR THURSDAY INTO FRIDAY...
TEMPERATURES WILL COOL TO MAINLY THE 70S FOR FRIDAY CONTINUING
INTO SATURDAY. SURFACE HIGH PRESSURE LOOKS TO BE IN CONTROL OF THE
WEATHER FROM THURSDAY THROUGH SATURDAY. HAVE IN A FEW CHANCES OF
SHOWERS/STORMS THROUGH THE PERIOD MAINLY EARLY WITH THE SURFACE
LOW AND COOL FRONT.
&&
.AVIATION...
12Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
WINDS WILL COME AROUND TO THE SOUTHWEST AND WEST AND INCREASE THIS
MORNING BEHIND A SURFACE LOW PRESSURE AREA MOVING ACROSS NORTHEAST
SD. OTHERWISE...AN UPPER LEVEL LOW PRESSURE TROUGH OUT WEST WILL
BE MOVING INTO THE REGION TODAY. THIS WILL SPREAD IN VFR MID LEVEL
CLOUDS ALONG WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FOR
LATE THIS MORNING INTO THE EARLY EVENING. INSERTED SOME VICINITY
SHOWERS IN FOR ALL LOCATIONS AT THIS TIME. THE CLOUDS AND
PRECIPITATION WILL MOVE OFF TO THE EAST THIS EVENING WITH WINDS
BECOMING LIGHT.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...TMT
SHORT TERM...CONNELLY
LONG TERM...MOHR
AVIATION...MOHR
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
950 AM EDT SUN AUG 31 2014
.DISCUSSION...CHALLENGE FOR FORECAST THIS MORNING IS HOW FAR EAST
THE STEADY STREAM OF SHOWERS AND TSRA SPREAD...AS THE SHORTWAVE
TROUGH TO OUR NORTH TRACKS ACROSS THE GREAT LAKES AND OHIO VALLEY.
THE SHORT RANGE MODELS...MAINLY THE HRRR AND RAP...SEEM MORE
REASONABLE IN KEEPING THE BEST COVERAGE ACROSS OUR WRN COUNIES.
FORECAST GRIDS GENERALLY IN LINE WITH THIS SCENARIO...BUT WILL
MONITOR RADAR DEVELOPMENTS FOR THE REST OF THE MORNING.
EXTENSIVE CLOUD COVER COULD HINDER MAX TEMPS THIS AFTERNOON...ALTHO
MIN TEMPS WERE VERY MILD...SO REACHING 80S TO NEAR 90 DEGREES IS
QUITE POSSIBLE.
FORECAST GRIDS AND PRODUCTS LOOK GOOD WITH NO UPDATES NEEDED UNLESS
THE SHOWERS WORK FURTHER EAST OF I-75 AND I-81...WHERE SCATTERED
WORDING AND HIGH CHANCE POPS ARE FORECAST.
&&
.PRELIMINARY POINT TEMPS/POPS...
CHATTANOOGA AIRPORT, TN 88 70 93 71 / 50 30 20 10
KNOXVILLE MCGHEE TYSON AIRPORT, TN 87 69 91 69 / 50 30 20 10
OAK RIDGE, TN 87 69 91 69 / 60 30 20 10
TRI CITIES AIRPORT, TN 86 66 87 63 / 50 40 20 10
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
TG
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1014 AM CDT SUN AUG 31 2014
.UPDATE...
SEE MORNING UPDATE.
&&
.DISCUSSION...
AT 9 AM...A WEAK TROUGH OR PERHAPS AN OUTFLOW EXTENDS FROM ABOUT
LEAGUE CITY TOM PALACIOS. MOISTURE IS PLENTIFUL AT 850 MB WITH DEW
PTS AT 16-17 C. AT 700 MB...A WEAK TROUGH EXTENDED FROM ABOUT
WHARTON TO MCALLEN WITH A WELL DEFINED 700 MB TROUGH AXIS
EXTENDING FROM ABOUT ST LOUIS TO TEXARKANA TO AUSTIN. AT 250
MB...A WELL DEFINED TROUGH AXIS EXTENDS FROM SE OK INTO CENTRAL
TEXAS. THE LIFT PROVIDED BY THE MID LEVEL TROUGHS AND DEEP
MOISTURE WILL SET THE STAGE FOR ADDITIONAL SHRA/TSRA THROUGH THE
MORNING. 12Z SOUNDINGS SHOW PW VALUES BETWEEN 2.2 AND 2.3
INCHES...NO CAPPING AND CONVECTIVE TEMPS IN LOWER 80S. RADAR IS
SHOWING A SWATH OF RAINFALL MAINLY ALONG AND EAST OF US HWY 59.
1 TO 3 INCHES OF RAIN HAS FALLEN OVER PARTS OF MATAGORDA AND
BRAZORIA COUNTIES WITH A BIT MORE ON THE WAY THIS MORNING. MODELS
INITIALIZED FAIRLY WELL SO AM EXPECTING THE RAINFALL TO CONTINUE
TO MOVE EAST AND NORTH THROUGH THE MORNING WITH RAINFALL BEGINNING
TO DIMINISH BY EARLY THIS AFTN. CURRENT FCST LOOKS ON TRACK BUT
MAY TWEAK TEMPS DOWN A BIT IN THE RAIN COOLED AIR. 43
&&
.PREV DISCUSSION... /ISSUED 644 AM CDT SUN AUG 31 2014/
DISCUSSION...
SEE AVIATION FOR 12Z TAF DISCUSSION.
AVIATION...
BAND OF SHRA WITH A FEW ISOLATED TSRA EMBEDDED CONTINUES TO LIFT
SLOWLY NORTHWARD ALONG THE US 59 CORRIDOR. HI RES MODELS INDICATE
THIS ACTIVITY WILL CONTINUE TO SPREAD NORTHWARD THROUGH THE DAY
AND FILL IN FURTHER EAST. BEST COVERAGE AND TSRA CHANCES LOOK TO
REMAIN ALONG AND WEST OF INTERSTATE 45 WITH COVERAGE DIMINISHING
BY LATE AFTERNOON. LOW CLOUDS REDEVELOP AFTER MIDNIGHT WITH MVFR
CIGS POSSIBLE BY DAYBREAK ON MONDAY. 38
PREV DISCUSSION... /ISSUED 439 AM CDT SUN AUG 31 2014/
DISCUSSION...
ALTHOUGH THERE WAS PLENTY OF TROPICAL MOISTURE AND LIFT FROM AN
UPPER LEVEL TROUGH AXIS...THE MAJORITY OF CONVECTION FORMED IN THE
GULF OF MEXICO AND MOVED INTO E TX AND SW LA. LAKE CHARLES ENDED
UP WITH 7.87 INCHES OF RAIN FOR YESTERDAY. THERE IS A SIMILAR
ENVIRONMENT IN PLACE TODAY WITH TROPICAL MOISTURE STILL OVER MUCH
OF SE TX AND UPPER TX COAST. THE TROUGH AXIS IS SLOWLY WEAKENING
BUT STILL COULD BE A FOCUS FOR CONVECTIVE ACTIVITY. BOTH 00Z
LCH/CRP SOUNDINGS SHOWED 2.2 INCHES OF PRECIP WATER AND GOES
SOUNDER DATA ALSO DEPICTS A SWATH OF TROPICAL MOISTURE STRETCHING
SW TO NE ACROSS THE TX COAST. BASED ON WATER VAPOR IMAGERY TROUGH
AXIS SHOULD BE MOVING OUT OF THE AREA AS UPSTREAM SHORT WAVE
TROUGH MOVES ACROSS THE ROCKIES AND INTO THE PLAINS LATER
TODAY/TONIGHT. THIS SHOULD ALSO HELP ADVECT TROPICAL MOISTURE OVER
THE REGION THIS MORNING AND AFTERNOON. HI RES MODELS WRF-
ARW/RAP/HRRR DEVELOP CONVECTION ALONG THE UPPER TX COAST AND MOVE
IT INTO THE COASTAL COUNTIES AROUND 12Z THIS MORNING. RADAR
ALREADY SHOWING SOME SHOWER ACTIVITY FROM MATAGORDA BAY AND
OFFSHORE. THIS SEEMS TO BE MATCHING THE TRENDS IN THE SHORT RANGE
HI RES MODELS. THE NAM/GFS/ECMWF ALSO SUPPORT THE IDEA OF A SWATH
OF PRECIP EMBEDDED WITHIN MAIN TROPICAL MOISTURE AXIS. DECIDED TO
KEEP MENTION OF 60 POPS. AGAIN WITH THIS MUCH MOISTURE STRONGER
STORMS WILL BE CAPABLE OF 1-2 INCHES OF RAIN AN HOUR. ACCUMULATED
PRECIP TOTALS FROM 06Z HRRR SHOW SWATH OF 2-4 INCHES OF RAIN BY
21Z THIS AFTERNOON SO ISOLATED HIGHER AMOUNTS OF RAIN WILL BE
POSSIBLE. MODELS DO INDICATE RAINFALL COMING TO AN END LATE
AFTERNOON AND EVENING SO DECREASED RAIN CHANCES FOR THE AFTERNOON.
OVERALL MOISTURE TRENDS IN NAM/GFS KEEP NEARLY 2 INCHES OF PRECIP
WATER OVER THE TX COAST THROUGH THE MIDDLE OF THE WEEK. A TROPICAL
WAVE IN THE NW CARIBBEAN SHOULD BE MOVING ACROSS THE YUCATAN TODAY
AND TOMORROW. NHC GIVES THIS WAVE A 50 PERCENT CHANCE OF BECOMING
A TROPICAL CYCLONE OVER NEXT 5 DAYS. ITS BEST CHANCE TO DO SO PER
LATEST MODEL GUIDANCE WILL NOT BE UNTIL IT EMERGES IN THE GULF.
EVEN THEN ONLY THE NAM REALLY DEVELOPS THE SYSTEM INTO A CLOSED
CIRCULATION. THE GFS/ECMWF KEEP IT AS AN OPEN WAVE WHICH HAS BEEN
WAY MORE CONSISTENT THAN THE NAM. OVERALL IMPACT TO TX WILL BE TO
KEEP A FETCH OF DEEP MOISTURE OFF THE GULF IN PLACE. THIS SHOULD
ALLOW FOR DAILY RAIN CHANCES FOR THE NEXT WEEK WITH DAY TIME
HEATING DRIVING CONVECTIVE TRENDS. COVERAGE IN CONVECTION WILL BE
THE REAL ISSUE AS GLOBAL MODELS ESTABLISH A BROAD ELONGATED UPPER
LEVEL RIDGE OVER MUCH OF THE SOUTHERN U.S. THE STRENGTH OF THE
RIDGE IS ALSO A QUESTION SO DIFFICULT TO GAGE HOW MUCH SUBSIDENCE
WILL BE OCCURRING DUE TO THE RIDGE. WITH THESE FACTORS IN MIND THE
FORECAST WILL KEEP AT LEAST SOME MENTION OF THUNDERSTORMS EACH
DAY. IT LOOKS LIKE THE HIGHER RAIN CHANCES WILL BE TUE/WED AS THIS
IS WHEN TROPICAL MOISTURE FROM THE TROPICAL WAVE MAY IMPACT THE
AREA. FORECAST WILL GO WITH 30/40 POPS FOR THESE DAYS WITH 20 POPS
FOR THE REST OF THE WEEK.
TEMPERATURES FOR THE WEEK WILL BE ABOVE NORMAL BUT STILL THE MORE
TYPICAL SUMMER TIME TEMPERATURES. MIN TEMPS IN THE MID/UPPER 70S
WILL BE EXPECTED WITH MAX TEMPS IN THE LOW/MID 90S. TEMPS WILL BE
GREATLY INFLUENCED BY CONVECTION AND RESULTING CLOUD COVER. AS IT
STANDS...WITH 100F NOT EXPECTED FOR A HIGH TEMPERATURE AT KCLL OR
KIAH TODAY...THE STREAK OF NOT REACHING 100F FOR A HIGH
TEMPERATURE CONTINUES INTO SEPTEMBER. HOPEFULLY IT STAYS THAT WAY
FOR THE REST OF THE YEAR.
39
MARINE...
SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP THIS
MORNING ACROSS THE COASTAL WATERS AS DEEP TROPICAL MOISTURE MOVES
BACK INTO THE REGION. EXPECT ONSHORE FLOW TO PERSIST THROUGH MUCH
OF THE UPCOMING WEEK. WIND SPEEDS WILL INCREASE LATE MONDAY NIGHT
INTO TUESDAY AND CAUTION FLAGS MAY BE NEEDED FOR THE COASTAL
WATERS. 38
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 94 76 95 76 95 / 20 10 20 10 20
HOUSTON (IAH) 91 77 93 77 93 / 60 10 30 20 30
GALVESTON (GLS) 88 81 89 82 89 / 60 10 30 30 40
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
644 AM CDT SUN AUG 31 2014
.DISCUSSION...
SEE AVIATION FOR 12Z TAF DISCUSSION.
&&
.AVIATION...
BAND OF SHRA WITH A FEW ISOLATED TSRA EMBEDDED CONTINUES TO LIFT
SLOWLY NORTHWARD ALONG THE US 59 CORRIDOR. HI RES MODELS INDICATE
THIS ACTIVITY WILL CONTINUE TO SPREAD NORTHWARD THROUGH THE DAY
AND FILL IN FURTHER EAST. BEST COVERAGE AND TSRA CHANCES LOOK TO
REMAIN ALONG AND WEST OF INTERSTATE 45 WITH COVERAGE DIMINISHING
BY LATE AFTERNOON. LOW CLOUDS REDEVELOP AFTER MIDNIGHT WITH MVFR
CIGS POSSIBLE BY DAYBREAK ON MONDAY. 38
&&
.PREV DISCUSSION... /ISSUED 439 AM CDT SUN AUG 31 2014/
DISCUSSION...
ALTHOUGH THERE WAS PLENTY OF TROPICAL MOISTURE AND LIFT FROM AN
UPPER LEVEL TROUGH AXIS...THE MAJORITY OF CONVECTION FORMED IN THE
GULF OF MEXICO AND MOVED INTO E TX AND SW LA. LAKE CHARLES ENDED
UP WITH 7.87 INCHES OF RAIN FOR YESTERDAY. THERE IS A SIMILAR
ENVIRONMENT IN PLACE TODAY WITH TROPICAL MOISTURE STILL OVER MUCH
OF SE TX AND UPPER TX COAST. THE TROUGH AXIS IS SLOWLY WEAKENING
BUT STILL COULD BE A FOCUS FOR CONVECTIVE ACTIVITY. BOTH 00Z
LCH/CRP SOUNDINGS SHOWED 2.2 INCHES OF PRECIP WATER AND GOES
SOUNDER DATA ALSO DEPICTS A SWATH OF TROPICAL MOISTURE STRETCHING
SW TO NE ACROSS THE TX COAST. BASED ON WATER VAPOR IMAGERY TROUGH
AXIS SHOULD BE MOVING OUT OF THE AREA AS UPSTREAM SHORT WAVE
TROUGH MOVES ACROSS THE ROCKIES AND INTO THE PLAINS LATER
TODAY/TONIGHT. THIS SHOULD ALSO HELP ADVECT TROPICAL MOISTURE OVER
THE REGION THIS MORNING AND AFTERNOON. HI RES MODELS WRF-
ARW/RAP/HRRR DEVELOP CONVECTION ALONG THE UPPER TX COAST AND MOVE
IT INTO THE COASTAL COUNTIES AROUND 12Z THIS MORNING. RADAR
ALREADY SHOWING SOME SHOWER ACTIVITY FROM MATAGORDA BAY AND
OFFSHORE. THIS SEEMS TO BE MATCHING THE TRENDS IN THE SHORT RANGE
HI RES MODELS. THE NAM/GFS/ECMWF ALSO SUPPORT THE IDEA OF A SWATH
OF PRECIP EMBEDDED WITHIN MAIN TROPICAL MOISTURE AXIS. DECIDED TO
KEEP MENTION OF 60 POPS. AGAIN WITH THIS MUCH MOISTURE STRONGER
STORMS WILL BE CAPABLE OF 1-2 INCHES OF RAIN AN HOUR. ACCUMULATED
PRECIP TOTALS FROM 06Z HRRR SHOW SWATH OF 2-4 INCHES OF RAIN BY
21Z THIS AFTERNOON SO ISOLATED HIGHER AMOUNTS OF RAIN WILL BE
POSSIBLE. MODELS DO INDICATE RAINFALL COMING TO AN END LATE
AFTERNOON AND EVENING SO DECREASED RAIN CHANCES FOR THE AFTERNOON.
OVERALL MOISTURE TRENDS IN NAM/GFS KEEP NEARLY 2 INCHES OF PRECIP
WATER OVER THE TX COAST THROUGH THE MIDDLE OF THE WEEK. A TROPICAL
WAVE IN THE NW CARIBBEAN SHOULD BE MOVING ACROSS THE YUCATAN TODAY
AND TOMORROW. NHC GIVES THIS WAVE A 50 PERCENT CHANCE OF BECOMING
A TROPICAL CYCLONE OVER NEXT 5 DAYS. ITS BEST CHANCE TO DO SO PER
LATEST MODEL GUIDANCE WILL NOT BE UNTIL IT EMERGES IN THE GULF.
EVEN THEN ONLY THE NAM REALLY DEVELOPS THE SYSTEM INTO A CLOSED
CIRCULATION. THE GFS/ECMWF KEEP IT AS AN OPEN WAVE WHICH HAS BEEN
WAY MORE CONSISTENT THAN THE NAM. OVERALL IMPACT TO TX WILL BE TO
KEEP A FETCH OF DEEP MOISTURE OFF THE GULF IN PLACE. THIS SHOULD
ALLOW FOR DAILY RAIN CHANCES FOR THE NEXT WEEK WITH DAY TIME
HEATING DRIVING CONVECTIVE TRENDS. COVERAGE IN CONVECTION WILL BE
THE REAL ISSUE AS GLOBAL MODELS ESTABLISH A BROAD ELONGATED UPPER
LEVEL RIDGE OVER MUCH OF THE SOUTHERN U.S. THE STRENGTH OF THE
RIDGE IS ALSO A QUESTION SO DIFFICULT TO GAGE HOW MUCH SUBSIDENCE
WILL BE OCCURRING DUE TO THE RIDGE. WITH THESE FACTORS IN MIND THE
FORECAST WILL KEEP AT LEAST SOME MENTION OF THUNDERSTORMS EACH
DAY. IT LOOKS LIKE THE HIGHER RAIN CHANCES WILL BE TUE/WED AS THIS
IS WHEN TROPICAL MOISTURE FROM THE TROPICAL WAVE MAY IMPACT THE
AREA. FORECAST WILL GO WITH 30/40 POPS FOR THESE DAYS WITH 20 POPS
FOR THE REST OF THE WEEK.
TEMPERATURES FOR THE WEEK WILL BE ABOVE NORMAL BUT STILL THE MORE
TYPICAL SUMMER TIME TEMPERATURES. MIN TEMPS IN THE MID/UPPER 70S
WILL BE EXPECTED WITH MAX TEMPS IN THE LOW/MID 90S. TEMPS WILL BE
GREATLY INFLUENCED BY CONVECTION AND RESULTING CLOUD COVER. AS IT
STANDS...WITH 100F NOT EXPECTED FOR A HIGH TEMPERATURE AT KCLL OR
KIAH TODAY...THE STREAK OF NOT REACHING 100F FOR A HIGH
TEMPERATURE CONTINUES INTO SEPTEMBER. HOPEFULLY IT STAYS THAT WAY
FOR THE REST OF THE YEAR.
39
MARINE...
SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP THIS
MORNING ACROSS THE COASTAL WATERS AS DEEP TROPICAL MOISTURE MOVES
BACK INTO THE REGION. EXPECT ONSHORE FLOW TO PERSIST THROUGH MUCH
OF THE UPCOMING WEEK. WIND SPEEDS WILL INCREASE LATE MONDAY NIGHT
INTO TUESDAY AND CAUTION FLAGS MAY BE NEEDED FOR THE COASTAL
WATERS. 38
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 94 76 95 76 95 / 20 10 20 10 20
HOUSTON (IAH) 91 77 93 77 93 / 40 10 30 20 30
GALVESTON (GLS) 88 81 89 82 89 / 60 10 30 30 40
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...39
AVIATION/MARINE...38
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
744 AM EDT SUN AUG 31 2014
.SYNOPSIS...
THE REGION WILL STAY BETWEEN A LARGE HIGH PRESSURE SYSTEM OVER
THE SOUTHEAST UNITED STATES AND WESTERN ATLANTIC AND A COMPLEX LOW
PRESSURE SYSTEM CROSSING THE GREAT LAKES. A COLD FRONT FINALLY
ARRIVES FROM THE NORTH BY THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 400 AM EDT SUNDAY...
ELONGATED BAROCLINIC ZONE IS SUPPORTED BY AN UPPER JET AND AXIS OF
VORTICITY THAT EXTENDS FROM THE LOWER MISSISSIPPI VALLEY TO NEW
ENGLAND. UPPER RIDGE REMAINS PARKED OVER THE NORTH CAROLINA COAST.
BAND OF DEEPER MOISTURE SHOWN ON WATER VAPOR AND TOTAL PRECIPITABLE
WATER IMAGES WILL MAKE ONLY SLOW PROGRESS EAST INTO THE COUNTY
WARNING AREA BY MONDAY MORNING.
MODELS BRING CLUSTER OF SHOWERS AND THUNDERSTORMS OVER KENTUCKY AND
TENNESSEE ACROSS MUCH OF THE FORECAST AREA THIS MORNING. NOT SURE
HOW FAR EAST THIS PRECIPITATION WILL GET. 06Z HRRR HAD REASONABLE
TIMING MOVING THE EASTERN EDGE INTO THE FORECAST AREA THROUGH 8AM
SO WILL BE FOLLOWING THAT ALONG WITH RADAR TRENDS.
LARGER BAND OF SHOWERS WILL PIVOT ENOUGH TO REACH SOUTHEAST WEST
VIRGINIA TONIGHT...SIMILAR TO ORIENTATION OF WPC QPF FORECAST AND
THE 00Z GFS...SLIGHTLY FARTHER SOUTH THAN THE 00Z NAM.
4KM NAM AND HRRR DEVELOP THUNDERSTORMS ALONG THE BLUE RIDGE THIS
AFTERNOON...CLOSE TO THE EDGE OF THE THICKER CLOUD COVER. EXPECT
THE COVERAGE OF THUNDERSTORMS IN THE EAST TO DIMINISH AFTER SUNSET.
CLOUDS WILL LIMIT HEATING AND INSTABILITY TODAY. STAYED CLOSER TO
BIAS CORRECTED MAV GUIDANCE FOR MAXIMUM TEMPERATURES. HUMID AIR MASS
AND VERY MILD DEW POINTS WILL RESULT IN LITTLE COOLING TONIGHT. USED
WARMER MET GUIDANCE FOR OVERNIGHT LOWS.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
AS OF 300 AM EDT SUNDAY...
PROGRESSIVE NORTHERN STREAM FLOW WILL PRODUCE TROUGHING ACROSS THE
NORTHEAST BY MONDAY MORNING. SEVERAL SHORTWAVES TRAVERSE ACROSS THE
MID ATLANTIC REGION. THESE UPPER DISTURBANCES WILL SHAPE THE TIMING
OF CONVECTION.
AN UPPER DISTURBANCE WILL SHIFT ACROSS THE GREAT LAKES FROM THE OHIO
RIVER VALLEY MONDAY MORNING...ENHANCING THE CHANCES OF SHOWERS IN
THE WEST-NORTHWEST. THE SUBTROPICAL BERMUDA HIGH PRESSURE WILL
REMAIN IN PLACE. A VERY MOIST SOUTHWEST FLOW WILL CONTINUE LABOR
DAY. HIGH TEMPERATURES MONDAY WILL RANGE FROM THE UPPER 70S IN THE
MOUNTAINS TO THE LOWER 90S IN THE PIEDMONT.
SCATTERED SHOWERS AND THUNDERSTORMS REDEVELOP MONDAY AFTERNOON WITH
SOLAR HEATING. SOME OF THE THUNDERSTORMS MAY CONTAIN LOCALLY HEAVY
RAINS. RAINFALL WILL DIMINISH QUICKLY AS THE SUN SETS AND SHOULD SEE
DRY...ALBEIT WARM AND MUGGY...CONDITIONS PERSIST THROUGH MONDAY
NIGHT. LOW TEMPERATURES MONDAY NIGHT WILL VARY FROM THE LOWER 60S IN
THE WEST TO THE AROUND 70 IN THE EAST.
DEEP LAYER MOISTURE INCREASES TUESDAY AS ANOTHER LOW PRESSURE SYSTEM
MOVING ACROSS EASTERN CANADA WILL DRAG A COLD FRONT SOUTH OF THE
GREAT LAKES. BETTER CHANCES FOR CONVECTION WILL BE FOUND ACROSS THE
HIGHER TERRAIN...WHERE STRONGER UPPER LEVEL SUPPORT WILL BE LOCATED.
HIGHS TUESDAY WILL CLIMB INTO THE LOWER 80S IN THE MOUNTAINS TO THE
LOWER 90S IN THE PIEDMONT.
MODEL TREND HAVE BEEN SLOWING THE TIMING OF THE FRONT AND EXPECT THE
COLD FRONT WILL STALL FURTHER NORTH TUESDAY NIGHT DUE TO THE UPPER
LEVEL RIDGING IN PLACE ACROSS THE SOUTHEAST STATES. LOWS WILL FALL
INTO THE MID 60S TO THE LOW 70S TUESDAY NIGHT.
KEPT THE HIGHEST POPS ACROSS THE SOUTH WEDNESDAY ALONG THE STALLED
FRONTAL BOUNDARY. WHILE...HIGH PRESSURE PASSING ACROSS THE GREAT
LAKES SHOULD KEEP THE NORTHERN HALF OF OUR AREA DRY. HIGHS WEDNESDAY
WILL BE FROM THE LOWER 80S IN THE WEST TO AROUND 90 DEGREES IN THE
EAST. SLOWLY DRY THINGS OUT WEDNESDAY NIGHT FROM NORTH TO SOUTH. LOW
TEMPERATURES WILL DROP INTO THE UPPER 50S IN THE NORTHWEST MOUNTAINS
TO NEAR 70 DEGREES IN THE PIEDMONT.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 330 PM SATURDAY...
UPPER LEVEL RIDGING WILL SHIFT NORTHWARD FROM THE SOUTHEAST STATES
OVER THE MID ATLANTIC DURING THE SECOND HALF OF THE WEEK...RESULTING
IN BOTH WARMER TEMPERATURES AND WEAKER WINDS ALOFT. THIS WILL MAKE
FOR MORE STABLE CONDITIONS THAT WILL KEEP SHOWER AND THUNDERSTORM
ACTIVITY DISORGANIZED THROUGH THE PERIOD. ANY RAINFALL WHICH
DEVELOPS WILL BE DRIVEN MAINLY BY DAYTIME HEATING...WHICH WILL ALLOW
THIS ACTIVITY TO FIZZLE AFTER SUNSET.
HIGH PRESSURE WILL PASS OFF THE NEW ENGLAND COAST ON THURSDAY...
RESULTING IN A WEAK WEDGING PATTERN WITH EASTERLY FLOW OFF THE
ATLANTIC. THIS WILL LIKELY BE THE DRIEST DAY OF THE PERIOD.
WINDS WILL SHIFT SOUTHWESTERLY AGAIN ON FRIDAY AS ANOTHER COLD FRONT
SINKS SOUTH FROM THE GREAT LAKES. STRONGER FLOW OFF THE ATLANTIC
WILL RESULT IN INCREASED MOISTURE...AND WILL EXPECT SPOTTY SHOWER
AND THUNDERSTORM ACTIVITY DURING THE AFTERNOON AND EVENING.
EXPECT TEMPERATURES TO REMAIN SLIGHTLY ABOVE NORMAL FOR THE PERIOD.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
AS OF 735 AM EDT SUNDAY...
SATELLITE PICTURES SHOWED AN AREA OF IFR CLOUDS SPREADING NORTH
OUT OF NORTH CAROLINA. THESE CLOUDS MAY BRIEFLY REACH KLYH OR KDAN
BEFORE 10AM.
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WERE MOVING NORTH-
NORTHEAST ACROSS THE CENTRAL APPALACHIANS THIS MORNING. EXPECT
RAIN AT KROA/KBCB AND KLWB THROUGH 14Z/10AM THIS MORNING. CEILINGS
AND VISIBILITIES WILL REMAIN VFR IN ALL BUT THE HEAVIEST SHOWERS.
THE PRECIPITATION WILL GRADUALLY DIMINISH THIS MORNING AS IT MOVES
EAST. THERE WILL BE A BREAK IN THE PRECIPITATION THROUGH ABOUT
1PM/17Z...THEN MORE SHOWERS AND THUNDERSTORMS WILL DEVELOP. HRRR
GUIDANCE SHOWED THE MOST LIKELY LOCATION FOR REDEVELOPMENT WILL BE
ALONG THE BLUE RIDGE. BUT THIS WILL DEPEND ON HOW MUCH HEATING AND
RESULTING INSTABILITY HAS OCCURRED. MEDIUM CONFIDENCE ON THE
LOCATION OF STORMS THIS AFTERNOON AND EVENING.
ONCE THE PRECIPITATION MOVES OUT OF THE AREA LATE TONIGHT...HIGH
AMOUNTS OF LOW LEVEL MOISTURE...ALONG WITH SOME BREAKS IN THE
CLOUD COVER WILL RESULT IN FOG FORMATION. HIGH CONFIDENCE OF MVFR
FOG ACROSS THE REGION LATE TONIGHT.
EXTENDED DISCUSSION...
IMPULSES EXIT BY MONDAY LEAVING THE REGION IN BETWEEN THIS
EXITING SYSTEM AND THE NEXT UPSTREAM COLD FRONT. THIS SHOULD ALLOW
FOR MORE IN THE WAY OF WIDESPREAD VFR ON MONDAY AFTER EARLY FOG
FADES...WITH ONLY ISOLATED CONVECTION LIKELY DURING THE AFTERNOON
INCLUDING SPOTTY MVFR CONDITIONS.
ANOTHER COLD FRONT IS EXPECTED TO PRODUCE SIMILAR CONDITIONS AS IT
APPROACHES FROM THE NW TUESDAY...THEN BETTER COVERAGE OF
SHRA/TSRA WEDNESDAY WITH THE FRONT PASSING...AND ACROSS THE SOUTH
THURSDAY WHERE THE BOUNDARY STALLS. HOWEVER LOW CONFIDENCE ON THE TIMING
AND SOUTHWARD POSITION OF THE BOUNDARY AT THIS POINT. THUS
APPEARS MAINLY VFR FOR NOW TUE-THU OUTSIDE OF AFTERNOON/EVENING
CONVECTION AND TYPICAL EARLY MORNING FOG IN THE VALLEYS AND WHERE
EARLIER HEAVY RAIN OCCURRED.
&&
.EQUIPMENT...
AS OF 730 AM EDT FRIDAY ...
THE VISIBILITY SENSOR AT KDAN...DANVILLE REGIONAL AIRPORT...WILL
BE OUT OF SERVICE UNTIL FURTHER NOTICE. A PART HAS BEEN BACK-ORDERED.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...KK
LONG TERM...NF
AVIATION...AMS
EQUIPMENT...AMS
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
345 PM EDT SUN AUG 31 2014
.SYNOPSIS...
19Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS A PROGRESSIVE NORTHERN
STREAM PATTERN ACROSS THE CONUS OVER THE TOP OF AN ELONGATED WEST TO
EAST ORIENTED UPPER RIDGE EXTENDING FROM NORTHERN MEXICO...ACROSS
THE DEEP SOUTH AND INTO THE WESTERN ATLANTIC. POTENT SHORTWAVE /
MOMENTUM PUSH IS SEEN IN WV IMAGERY EJECTING OUT OF THE
INTER-MOUNTAIN WEST ACROSS THE NORTHERN PLAINS. THIS ENERGY IS
EXPECTED TO RESULT IN A LARGE AREA OF SEVERE POTENTIAL ACROSS THE
NORTHERN PLAINS/UPPER MS VALLEY THIS EVENING. CLOSER TO HOME WE FIND
OUR REGION UNDERNEATH THE ELONGATED UPPER RIDGE MENTIONED
ABOVE...AND THIS RIDGE WILL BE STAYING PUT FOR THE NEXT SEVERAL
DAYS. A SWATH OF MID/UPPER LEVEL DRIER AIR IS CLEARLY SEEN ON WV
IMAGERY ARRIVING OVER THE FL PENINSULA FROM THE EAST... ALTHOUGH THE
12Z KTBW SOUNDING PROFILE WAS LAUNCHED AHEAD OF THIS PUSH...AND
LIKELY DID NOT SAMPLE MUCH OF THE THIS AIRMASS THAT IS NOW STREAMING
OVERHEAD. EVEN STILL...THE 12Z SOUNDING WAS ALREADY DRIER THAN 24
HOURS AGO WITH A PW VALUE DOWN A FEW TENTHS OF AN INCH TO AROUND
1.7".
REGIONAL RADARS SHOWING DISORGANIZED SHOWER/STORM ACTIVITY AHEAD OF
AND ALONG THE EAST COAST SEA-BREEZE WHICH IS QUICKLY TRANSLATING
ACROSS THE STATE THIS MID-AFTERNOON. SHOWERS AND STORMS ARE ALREADY
ARRIVING AROUND THE FORT MYERS AREA AND PROGRESSING WESTWARD THROUGH
POLK/HIGHLANDS/DESOTO/HARDEE COUNTIES FURTHER TO THE NORTH. AS
MENTIONED ABOVE...SO FAR THE CONVECTION IS RATHER DISORGANIZED AND
SHALLOW IN NATURE AS THE SYNOPTIC FLOW IS WITH THE SEA-BREEZE
FLOW...LIMITING LOW LEVEL FOCUS. DO EXPECT A LEAST SOME MORE ROBUST
CONVECTIVE CELLS IN THE NEXT SEVERAL HOURS AS THIS ACTIVITY AND THE
EAST COAST SEABREEZE ARRIVES AT THE I-75 CORRIDOR TO THE NORTH OF
FORT MYERS. HAVE SEEN SEVERAL OF THE COASTAL OBS FLIP AROUND ONSHORE
INDICATING SEA-BREEZE FORMATION...AND THIS SHOULD ENSURE MORE
PRONOUNCED CONVERGENCE FOR STRONG UPDRAFTS / DEEP CONVECTION INTO
THE EARLY EVENING HOURS. WE HAVE MIXED REALLY WELL SO FAR THIS
DIURNAL CYCLE WITH CU BASES AROUND THE REGION GENERALLY AT OR ABOVE
5KFT. THIS SUGGEST WE NOW HAVE A DEEP MIXED LAYER / INVERTED V
PROFILE IN THE LOWER LEVELS. WITH THIS IN MIND...STILL BELIEVE WE
ARE LOOKING AT AN ENHANCED WIND GUST THREAT FROM THE STRONGER
STORMS...AND THIS POTENTIAL WILL NEED TO BE WATCHED CLOSELY ON RADAR
THROUGH THE EARLY EVENING PERIOD.
&&
.SHORT TERM (TONIGHT AND MONDAY)...
ANY LINGERING STORMS WILL BE QUICKLY EXITING INTO THE GULF WITHIN A
COUPLE HOURS OF SUNSET...WHICH WILLS SET UP A MOSTLY DRY AND
SEASONABLE OVERNIGHT PERIOD. SIMILAR TO SATURDAY NIGHT...STORMS MAY
LINGER FOR A FEW EXTRA HOURS UP OVER THE COASTAL NATURE COAST BEFORE
EVEN HERE THE ACTIVITY DIMINISHES AND PUSHES OFFSHORE. WITH THE FAST
PROGRESSION OF ACTIVITY FROM EAST TO WEST...THE DURATION OF RAINFALL
FOR ANY ONE LOCATIONS DOES NOT LOOK TO BE ALL THAT GREAT...HOWEVER
THE CHANCES FOR A PASSING STORM ARE FAIRLY HIGH...ESPECIALLY FROM
PASCO/HERNANDO COUNTIES SOUTHWARD. CURRENT GRIDS SHOWS 60-70%
COVERAGE THE NEXT SEVERAL HOURS...AND FEEL THIS FORECAST IS STILL
VALID.
THE OVERALL SYNOPTIC PATTERN DOES NOT CHANGE MUCH HEADING INTO
LABOR DAY...AND HENCE NEITHER WILL THE FORECAST. EASTERLY FLOW WILL
CONTINUE TO DOMINATE THE REGION ON THE SOUTHERN SIDE OF THE
SUBTROPICAL RIDGE AXIS LOCATED NEAR THE I-10 CORRIDOR. MANY OF THE
THERMODYNAMIC PARAMETERS THROUGH THE COLUMN LOOK SIMILAR TO TODAY
SUGGESTING WIND WILL AGAIN BE THE PRIMARY THREAT WITH ANY OF THE
STRONGER STORMS. FORECAST WILL SHOW A QUIET AND MAINLY RAIN FREE
MORNING AND EARLY AFTERNOON...FOLLOWED BY INCREASING STORM CHANCES
ARRIVING FROM THE EAST WITH THE SEA-BREEZE. THE PEAK OF THE STORMS
SHOULD AGAIN FALL BETWEEN 2 AND 6 PM TO THE SOUTH OF SARASOTA...AND
4 TO 8 PM FURTHER NORTH THROUGH THE I-4 CORRIDOR AND UP INTO THE
NATURE COAST.
&&
.LONG TERM (TUESDAY NIGHT THROUGH SATURDAY)...
NOT MUCH CHANGE FOR THE ONGOING LONG TERM FORECAST. THE ATLANTIC
SURFACE RIDGE WILL REMAIN GENERALLY NORTHEAST OF THE AREA...WITH
EAST OR SOUTHEAST FLOW CONTINUING. A MID/UPPER-LEVEL LOW WILL MAKE
ITS WAY WEST-NORTHWESTWARD TOWARD THE EAST COAST OF FLORIDA THROUGH
MID TO LATE WEEK. THE GFS SHOWS A MORE WELL-DEFINED FEATURE WITH 500
MB TEMPS COOLING SLIGHTLY TO -8 DEGREES CELSIUS OVER OUR
SOUTHERNMOST ZONES WHILE THE ECMWF IS NOT QUITE AS DEFINED BUT DOES
STILL SHOW SOME COOL TEMPS ALOFT OF AROUND -7. ANOTHER FACTOR FOR
WEDNESDAY WILL BE THE DRIER AIR THAT MOVES OVER THE REGION...WHICH
WOULD TEND TO SCALE BACK POPS A BIT...THOUGH STILL IN THE SCATTERED
RANGE...BUT SOME OF THE STORMS THAT DO FORM COULD BE ON THE STRONGER
SIDE WITH THE COOLING 500 MB TEMPS. OTHERWISE...EXPECT FAIRLY
TYPICAL SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WITH AN
EAST TO SOUTHEAST FLOW. TEMPERATURES LOOK TO REMAIN AROUND NORMAL
VALUES FOR THE PERIOD.
&&
.AVIATION...
VFR CONDITIONS PREVAIL ACROSS THE FORECAST AREA LATE THIS MORNING AS
WE AWAIT MORE LATE DAY STORMS. STORMS LATE THIS AFTERNOON AND EARLY
EVENING WILL HAVE AN ENHANCED WIND THREAT. OTHERWISE...AWAY FROM THE
STORMS EXPECT VFR CONDITIONS TO CONTINUE. STORMS WILL PUSH OFFSHORE
WITHIN A COUPLE HOURS OF SUNSET.
&&
.MARINE...
HIGH PRESSURE RIDGING ACROSS THE NORTHEASTERN GULF OF MEXICO AND
FLORIDA PENINSULA WILL KEEP WINDS LESS THAN 15 KNOTS AND SEAS BELOW
3 FEET FOR THE NEXT SEVERAL DAYS. THE SEA BREEZE WILL SET UP ALONG
THE COASTLINE EACH DAY TURNING THE WINDS TO AN ONSHORE FLOW IN THE
AFTERNOON. SCATTERED SHOWERS AND STORMS WILL BE POSSIBLE EACH DAY
DEVELOPING OVER LAND AND THEN PUSHING WESTWARD OVER THE COASTAL
WATERS DURING THE EVENING HOURS. THE ONLY EXPECTED HAZARD WILL BE
GUSTY WINDS AND HIGHER SEAS IN THE VICINITY OF THUNDERSTORMS.
&&
.FIRE WEATHER...
HIGH PRESSURE WILL REMAIN ALIGNED OVER THE NORTHERN PORTION OF THE
STATE THROUGH THE MIDDLE OF THE WEEK. THIS PATTERN WILL KEEP AMPLE
ATLANTIC LOW LEVEL MOISTURE IN PLACE TO PREVENT ANY CRITICAL LEVELS
OF RELATIVE HUMIDITY. THUNDERSTORMS WILL BE MOST LIKELY ALONG THE
I-75 CORRIDOR DURING THE LATE AFTERNOON AND EVENING HOURS THE NEXT
SEVERAL DAYS.
FOG POTENTIAL...PATCHY GROUND FOG COULD DEVELOP LATE EACH
NIGHT...ESPECIALLY IN LOCATIONS THAT RECEIVE RAIN DURING THE
PREVIOUS EVENING. HOWEVER...NO SIGNIFICANT FOG IS ANTICIPATED
THROUGH THE MIDDLE OF THE WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 77 93 78 92 / 30 50 20 50
FMY 75 94 76 92 / 10 60 10 50
GIF 75 94 75 93 / 10 50 10 40
SRQ 75 92 76 91 / 30 60 20 50
BKV 72 93 73 93 / 40 50 20 40
SPG 79 93 80 91 / 40 60 30 50
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/AVIATION/FIRE WX...MROCZKA
MARINE...FLEMING
LONG TERM...CARLISLE
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
239 PM EDT SUN AUG 31 2014
.SYNOPSIS...
A PERSISTENT UPPER RIDGE WILL KEEP VERY WARM TEMPERATURES IN THE
FORECAST THIS WEEK. INCREASED LOW LEVEL MOISTURE WILL RESULT IN
CHANCES OF AFTERNOON STORMS AND HUMID CONDITIONS WITH HEAT INDICES
AT OR ABOVE 100 DEGREES.
&&
.NEAR TERM /THROUGH TONIGHT/...
WATER VAPOR IMAGERY EARLY THIS AFTERNOON INDICATES THE UPPER RIDGE
AXIS IS RIGHT OVERHEAD EXTENDING FROM SOUTHEAST VIRGINA THROUGH
THE CENTRAL CAROLINAS INTO SOUTHERN GEORGIA. PRECIPITABLE WATER
AXIS JUST UNDER 2 INCHES EXTENDS NORTHWARD ALONG THE I-20 CORRIDOR
AND REGIONAL RADAR SHOWING SCATTERED SHOWERS DEVELOPING ALONG THIS
AXIS IN SOUTHEAST GEORGIA INTO THE CSRA. HRRR HAD A GOOD HANDLE ON
THIS AND HAVE HIGHEST POPS THIS AFTERNOON IN THE SOUTHEAST PORTION
OF THE FORECAST AREA BUT STILL MAINTAINING CHANCE POPS. UPPER FLOW
REMAINS VERY WEAK WITH STORM MOTION GENERALLY 5 KNOTS OR LESS AND
CONVECTION HAS BEEN GOING UP AND RIGHT BACK DOWN FAIRLY QUICKLY AS
THEY RAIN THEMSELVES OUT. THINK SEVERE THREAT REMAINS LOW GIVEN
SUCH WARM AIR IN THE LOWER 20KFT AND SURFACE TEMPERATURES PUSHING
INTO THE MID AND UPPER 90S.
SOME LINGERING SHOWERS MAY EXIST THROUGH THE LATE EVENING HOURS
BUT EXPECT PRECIPITATION TO END BY 06Z OR SO WITH SOME CONVECTIVE
DEBRIS CLOUD OVER THE AREA TONIGHT. TEMPERATURES WILL BE WARM
AGAIN TONIGHT IN THE LOW TO MID 70S AFTER SUCH A WARM DAY WITH
CLOUD COVER AND ABUNDANT LOW LEVEL MOISTURE LIMITING RADIATIONAL
COOLING.
&&
.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
STRONG MID/UPPER LEVEL RIDGE CONTINUES TO HOLD ALONG THE
SOUTHEAST COAST INTO MONDAY NIGHT. S/W ENERGY ACROSS THE CNTRL/NRN
PLAINS WILL CONTINUE TO MOVE EASTWARD ACROSS THE GREAT LAKES AND
FLATTEN OUT THE AMPLITUDE OF THE RIDGE...BUT THE SOUTHEAST REMAINS
UNDER HIGHER HEIGHTS AND SEPARATE FROM THE MAIN W TO E FLOW. LOW
LEVEL FLOW REMAINS FROM THE SOUTH TO SOUTH-SOUTHWEST THROUGH THE
PERIOD. THIS WILL HELP TO KEEP LOW LEVEL MOISTURE IN PLACES WITH
DEWPOINTS RANGING FROM THE MIDDLE 60S TO LOWER 70S.
HOWEVER...CHANCES FOR SHOWERS/THUNDERSTORMS LOOK LOW THROUGH THE
PERIOD. GUIDANCE POPS ALONG WITH LACK OF UPPER TRIGGERS
INDICATING ONLY SLIGHT CHANCE POPS THROUGH THE PERIOD. CONVECTIVE
ACTIVITY WILL BE MAINLY DIURNAL IN NATURE WITH ONLY SOME WEAK
SURFACE CONVERGENCE/SEA BREEZE ACTION EACH DAY. AS FOR
TEMPERATURES...EXPECT AFTERNOON TEMPERATURES TO CONTINUE THE RUN
OF 5 TO 10 DEGREES ABOVE NORMAL. AS HIGHS THIS AFTERNOON HAVE
CLIMBED INTO THE UPPER 90S IN SOME AREAS...DECIDED TO RAISE
AFTERNOON HIGHS FOR MONDAY BASED ON CURRENT TRENDS AND BOUNDARY
LAYER/H8 TEMPS. EXPECT MIDDLE TO UPPER 90S ACROSS MOST LOCATIONS.
LIKE THIS AFTERNOON A LOCATION OR TWO MAY REACH THE CENTURY MARK.
OVERNIGHT LOWS WILL BE IN THE LOWER 70S. AFTERNOON HEAT INDEX
VALUES TOMORROW WILL CLIMB TO AROUND 105 DEGREES.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
NO REAL CHANGES TO THE EXTENDED FORECAST. UPPER RIDGE CONTINUES
OVER THE AREA FROM TUESDAY THROUGH NEXT WEEKEND. IN FACT THE RIDGE
BEGINS TO AMPLIFY ONCE AGAIN BEGINNING WEDNESDAY THROUGH FRIDAY.
THE THE MAIN FLOW ACROSS THE NORTHERN HALF OF THE U.S....EXPECT
S/W ACTIVITY TO REMAIN NORTH OF THE AREA FROM THE NRN PLAINS AND
GREAT LAKES INTO NEW ENGLAND/MID ATLANTIC REGION AND REMAINING
NORTH OF THE CWA. LOW-LEVEL MOISTURE CONTINUES TO SLOWLY INCREASE
DURING THE BEGINNING OF THE PERIOD AND REMAIN BETWEEN 1.5 AND 2.0
INCHES THROUGH THE WEEK AND INTO THE WEEKEND. A WEAK BOUNDARY
TRIES TO MOVE SOUTHWARD INTO THE REGION WEDNESDAY...BUT MODELS
CONTINUE TO SHOW IT HANGING UP JUST NORTH AND WEST OF THE CWA.
REMNANTS OF BOUNDARY LINGER JUST NORTH OF THE CWA THROUGH MUCH OF
THE WEEK. OTHERWISE...JUST A SLIGHT CHANCE/LOW CHANCE POPS THROUGH
THE PERIOD. STILL LOOKS TO BE DIURNAL IN NATURE WITH AFTERNOON
HEATING WITH WEAK SURFACE CONVERGENCE AND LITTLE/NO UPPER SUPPORT.
TEMPERATURES WILL CONTINUE TO BE ABOVE NORMAL THROUGH THE
REMAINDER OF THE LONG TERM PERIOD. EXPECT AFTERNOON HIGHS IN THE
LOW/MID 90S AND OVERNIGHT LOWS IN THE LOW/MID 70S. NORMALS HIGHS
ARE IN THE UPPER 80S AND LOWS NEAR 70.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
VFR CONDITIONS THROUGH MUCH OF THE PERIOD EXPECTED WITH ISOLATED
SHOWERS 18Z-02Z. HAVE INCLUDED VCSH AT CAE/CUB/AGS/DNL WITH RADAR
INDICATING CONVECTION DEVELOPING ALONG A WEAK CONVERGENCE LINE
POSITIONED ALONG THE I-20 CORRIDOR. THINK THE STRENGTH OF THE
UPPER RIDGE OVERHEAD WILL LIMIT CONVECTION AND POSSIBILITY OF
THUNDER SO NOT MENTIONING AT THIS TIME. SOUTHERLY WINDS AROUND 5
TO 10 MPH THIS AFTERNOON BECOMING LIGHT AND VARIABLE OVERNIGHT.
EXPECT SOME LIGHT MVFR FOG TO DEVELOP LATE TONIGHT GIVEN ABUNDANT
BOUNDARY LAYER MOISTURE IN PLACE...ALTHOUGH POSSIBLE DEBRIS CLOUDS
MAY IMPACT FOG POTENTIAL LEADING TO LOWER CONFIDENCE.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE IN LATE NIGHT
AND EARLY MORNING STRATUS AND FOG. SCATTERED MAINLY AFTERNOON
SHOWERS AND THUNDERSTORMS SUNDAY THROUGH THURSDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
150 PM CDT SUN AUG 31 2014
.DISCUSSION...
328 AM CDT
AFTER A FAIRLY QUIET DAY ACROSS THE AREA TODAY...ATTENTION QUICKLY
SHIFTS TO THE WEATHER FOR LABOR DAY INTO MONDAY NIGHT...DURING WHICH
PERIODS OF EXTREMELY HEAVY RAINFALL AND SEVERE WEATHER ARE POSSIBLE.
THUNDERSTORMS CONTINUED TO TRAIN ACROSS THE SAME AREAS ACROSS
PORTIONS OF FORD AND IROQUOIS COUNTIES IN ILLINOIS AND ALSO BENTON
COUNTY IN INDIANA YESTERDAY EVENING AND INTO THE OVERNIGHT HOURS.
THESE AREAS LIED IN THE RIGHT ENTRANCE REGION OF AN UPPER LEVEL JET
STREAK. THE COMBINATION OF THIS...AND THE CONTINUED LOW LEVEL
CONFLUENCE CONTINUED TO DRIVE THIS CONVECTION. RADAR ESTIMATES SOME
VERY HEFTY ISOLATED RAINFALL AMOUNTS IN EXCESS OF 4 INCHES ACROSS
PORTIONS OF THESE COUNTIES. ALTHOUGH SOME ISOLATED ACTIVITY
CONTINUES ACROSS THIS AREA AS OF THIS WRITING...IT IS EXPECTED THAT
ALL THIS ACTIVITY WILL SHIFT OUT OF THE AREA AROUND...OR JUST PRIOR
TO DAYBREAK AS THE UPPER LEVEL JET DEVELOPS EASTWARD.
WATER VAPOR IMAGERY EARLY THIS MORNING SHOWS THE NEXT UPPER LEVEL
SYSTEM CURRENTLY DIGGING ACROSS THE ROCKIES. AIRCRAFT AND UPPER AIR
OBSERVATIONS ACROSS WESTERN CANADA AND OVER THE NORTHEAST PACIFIC
INDICATE SOME IMPRESSIVE UPPER LEVEL WINDS...FOR THIS TIME OF
YEAR...IN EXCESS OF 110 KT WITHIN THE CORE OF THE JET STREAK
DIGGING OVER THE WESTERN CONUS. THE FIRST MID LEVEL IMPULSE IS
EXPECTED TO CONTINUE SHIFTING EASTWARD OVER THE UPPER MIDWEST INTO
MONDAY MORNING. AS IT DOES SO...IT WILL DRIVE A FAIRLY STOUT
SURFACE LOW NORTHEASTWARD FROM THE DAKOTAS TO ONTARIO. SOME VERY
SUBSTANTIAL CONVECTION IS EXPECTED TO DEVELOP AHEAD OF THE COLD
FRONT LATER TODAY ACROSS PORTIONS OF THE MID MISSOURI VALLEY AND
INTO MINNESOTA. THIS ACTIVITY WILL LIKELY SHIFT EAST-NORTHEASTWARD
OVERNIGHT TONIGHT...WITH SOME OF THE REMNANT ACTIVITY POSSIBLY
REACHING NORTH CENTRAL ILLINOIS BY AROUND...OR JUST PRIOR TO
DAYBREAK MONDAY. IT APPEARS THAT THIS INITIAL ROUND OF CONVECTION
COULD BE IN A WEAKENING PHASE AS IT TRIES TO PUSH OVER PORTIONS
OF NORTHERN ILLINOIS MONDAY MORNING. HOWEVER...RENEWED CONVECTIVE
DEVELOPMENT...POSSIBLY ALONG ANY OUTFLOW BOUNDARIES LAID DOWN BY
EARLY MORNING ACTIVITY...IS LIKELY ACROSS PORTIONS OF NORTHEASTERN
ILLINOIS AND NORTHWESTERN INDIANA BY MONDAY AFTERNOON.
MODEL SOUNDINGS ALL INDICATE FAVORABLE PROFILES FOR ACTIVE STRONG TO
SEVERE STORMS OVER THE AREA DURING THE AFTERNOON AND EARLY EVENING
MONDAY. DEEP LAYER BULK SHEAR LOOKS TO BE SOMEWHAT
UNIDIRECTIONAL...BUT WITH 0-6 KM SPEED SHEAR OF NEARLY 50
KT...ORGANIZED CONVECTIVE ACTIVITY APPEARS VERY POSSIBLE. THE MAIN
COMPLICATING FACTOR AT THIS POINT IS HOW MUCH ANY CLOUD DEBRIS OR
REMNANT MORNING CONVECTIVE ACTIVITY IMPACTS AFTERNOON HEATING AND
DESTABILIZATION ACROSS NORTHEASTERN ILLINOIS AND NORTHWESTERN
INDIANA. HOWEVER...IN SPITE OF THIS POSSIBILITY EARLY IN THE
DAY...IT DOES APPEAR THAT THE HIGH THETA E NEAR SURFACE AIR MASS
SHOULD BE ENOUGH TO PRODUCE AMPLE MLCAPE VALUES AT OR JUST IN
EXCESS OF 1500 J/KG...WHICH COMBINED WITH THE 45+ DEEP LAYER SHEAR
CERTAINLY POINTS TO A SEVERE THREAT. AT THIS TIME IT APPEARS
RATHER MODEST MID LEVEL LAPSE RATES WOULD RESULT IN THE MAIN
SEVERE THREAT BEING STRONG DAMAGING WIND GUSTS. HOWEVER...THERE IS
ALSO A SECONDARY THREAT OF LARGE HAIL...ESPECIALLY IF ANY SUPER
CELLS CAN FORM.
THERE IS ALSO A DECENT CONCERN FOR EXTREMELY HEAVY RAINFALL RATES
WITH THESE STORMS...WITH PWAT VALUES IN THIS JUICY ENVIRONMENT
LIKELY TO RESIDE AROUND 1.7 INCHES. NUMERICAL GUIDANCE CONTINUES TO
SUGGEST THAT A SECONDARY MID LEVEL IMPULSE WILL APPROACH THE AREA
MONDAY NIGHT AND ACT TO INDUCE/STRENGTHEN A SOUTHWESTERLY UPPER
LEVEL JET STREAK ACROSS THE GREAT LAKES REGION INTO MONDAY NIGHT.
THIS PROCESS COULD SET UP PORTIONS OF THE AREA WITHIN THE FAVORABLE
RIGHT ENTRANCE REGION OF A 100 KT UPPER LEVEL JET INTO TUESDAY
MORNING AS THE SURFACE COLD FRONTAL BOUNDARY SLOWLY TRIES TO SHIFT
SOUTHWARD ACROSS THE SOUTHERN HALF OF MY CWA. I HAVE INCREASING
CONCERNS THAT THIS COULD SET UP A VERY HEAVY RAIN EVENT MONDAY
NIGHT...WITH STORMS POTENTIALLY TRAINING TO THE EAST NORTHEAST
NEARLY PARALLEL TO THE SURFACE BOUNDARY. AT THIS TIME IT APPEARS THIS
HEAVY RAIN THREAT COULD END UP SOUTH OF INTERSTATE 80 MONDAY NIGHT.
HOWEVER...UNCERTAINTY IS STILL A BIT HIGH AS TO HOW FAR SOUTH THE
SURFACE FRONT WILL GET MONDAY NIGHT...AND HENCE WHERE THE MOST
FAVORED AREAS FOR TRAINING CELLS WILL OCCUR. AT THIS POINT...I HAVE
ADDED HEAVY RAIN WORDING TO THE FORECAST...MAINLY FOR AREAS SOUTH OF
INTERSTATE 80 INTO MONDAY NIGHT.
FOLLOWING THIS ACTIVE WEATHER MONDAY NIGHT IT APPEARS THE WEATHER
WILL BE DRY FOR THE MOST PART THROUGH LATE WEEK. THE MAIN STORY
HOWEVER...WILL BE THE INCREASING HEAT BY THURSDAY. FORECAST GUIDANCE
CONTINUES TO FORECAST MID LEVEL HEIGHTS TO BUILD SUBSTANTIALLY
ACROSS THE CENTRAL CONUS. THIS COULD LEAD TO A RUN AT
90 TEMPERATURES FOR THURSDAY AS 850 MB TEMPERATURES WARM TO 20 TO
22C. I HAVE STARTED CUTTING BACK ON THE SLIGHT CHANCE
POPS...ESPECIALLY ON WEDNESDAY AND WEDNESDAY NIGHT...BUT LEFT IN
SOME SLIGHTS FOR THURSDAY. ALTHOUGH SOME ISOLATED CONVECTIVE
ACTIVITY IS POSSIBLE DURING THIS TIME...IT APPEARS THAT THE BUILDING
HEIGHTS AND WARMING TEMPS ALOFT COULD END UP CAPPING THE AREA...AND
LIMITING THE THREAT FOR CONVECTIVE DEVELOPMENT THROUGH THURSDAY.
CONVECTIVE CHANCES DO LOOK TO RETURN TO THE AREA AGAIN BY FRIDAY.
ANOTHER SIGNIFICANT WAVE IS EXPECTED TO SHIFT EASTWARD ACROSS THE
NORTHERN CONUS AND SOUTHERN CANADA LATE IN THE PERIOD...AND THIS
LOOKS TO SHIFT A COLD FRONT SOUTHWARD ACROSS THE AREA SOMETIME
EITHER FRIDAY OR FRIDAY NIGHT AND THIS COULD SPARK OFF ACTIVITY
ACROSS THE AREA. COOLER WEATHER DOES LOOK TO OVERSPREAD TO AREA
UNDER NORTHERLY WINDS BY EARLY NEXT WEEKEND.
KJB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* LAKE BREEZE THIS AFTERNOON AND WHETHER OR NOT IT WILL PUSH
ACROSS ORD/MDW.
* GUSTY SOUTHWEST WINDS DEVELOPING MID MORNING MONDAY.
* CHANCES FOR THUNDERSTORMS...WITH A LOWER CHANCE OF LINGERING
PRECIP COMING IN TOMORROW MORNING...AND A BETTER CHANCE FOR NEW
DEVELOPMENT OF STRONG THUNDERSTORMS MONDAY AFTERNOON.
BMD
//DISCUSSION...UPDATED 18Z...
THIS AFTERNOON...WEAK HIGH PRESSURE IS IN PLACE TODAY ALLOWING FOR
GENERALLY LIGHT SOUTHWEST FLOW. A LAKE BREEZE HAS ALREADY
DEVELOPED THOUGH REMAINS FAIRLY CLOSE TO THE SHORE AT THIS HOUR.
IT IS UNCERTAIN WHETHER IT WILL MAKE IT ACROSS THE TERMINALS BUT
MOST GUIDANCE IS LEANING AGAINST THIS OCCURRING...AND IF IT DOES IT
WOULD LIKELY BE LATE.
ATTENTION TURNS TO THE WEST TONIGHT AS AN UPPER LEVEL DISTURBANCE
PUSHES ACROSS THE PLAINS KICKING OFF THUNDERSTORMS. THESE
THUNDERSTORMS ARE EXPECTED TO PERSIST THROUGH THE OVERNIGHT HOURS
MOVING INTO NORTHERN ILLINOIS EARLY MONDAY MORNING IN A DISSIPATING
STAGE. RFD HAS BEST CHANCE FOR SEEING SOME FESTERING EARLY MORNING
ACTIVITY SO ADDED A PROB30 FOR TSRA. DEPENDING ON HOW FAR EAST THIS
PRECIP MAKES IT EARLY MONDAY...EXPECT THE ATMOSPHERE TO RECOVER
BECOMING MODERATELY UNSTABLE WITH ADDITIONAL THUNDERSTORMS EXPECTED
TO REDEVELOP MONDAY AFTERNOON. THESE STORMS COULD BE STRONG TO
SEVERE WITH GUSTY WINDS THE PRIMARY THREAT.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* LOW CONFIDENCE IN LAKE BREEZE MAKING IT THROUGH ORD/MDW TODAY.
* LOW-MEDIUM CONFIDENCE IN CIGS REST OF TODAY.
* MEDIUM-HIGH CONFIDENCE IN WIND SPEEDS AND DIRECTION MONDAY.
* HIGH CONFIDENCE IN AT LEAST A PERIOD OF TSRA BUT LOW CONFIDENCE
IN SPECIFIC TIMING.
BMD
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...CHANCE SHRA/TSRA.
TUESDAY AND WEDNESDAY...VFR. WX NIL.
THURSDAY THROUGH SATURDAY...PERIODIC CHANCES FOR SHRA/TSRA.
KREIN
&&
.MARINE...
149 PM CDT
THE WEATHER PATTERN ACROSS THE WESTERN LAKES WILL BE FAIRLY
PROGRESSIVE OVER THE NEXT SEVERAL DAYS...WITH A PAIR OF SURFACE LOWS
PASSING ACROSS OR NORTH OF THE NORTHERN LAKES AND TRAILING COLD
FRONTS ACROSS LAKE MICHIGAN.
THE FIRST LOW...OVER FAR NORTHWEST MINNESOTA THIS AFTERNOON...WILL
MOVE NORTHEAST ACROSS ONTARIO AND THE NORTHERN LAKES THROUGH MONDAY
WITH ITS TRAILING COLD FRONT PUSHING SOUTHEAST ACROSS THE LAKE
MONDAY AFTERNOON AND EVENING. TIGHTENING OF THE GRADIENT AHEAD OF
THE LOW AND FRONTAL TROUGH WILL RESULT IN SOUTHERLY WINDS INCREASING
LATE TONIGHT AND MONDAY...WITH GUSTS REACHING THE 20-25 KT RANGE AND
CONTINUING INTO EARLY MONDAY EVENING BEFORE THE GRADIENT WEAKENS
ALONG THE COLD FRONTAL TROUGH. THIS FRONT WILL PUSH SOUTHEAST ACROSS
THE LAKE MONDAY NIGHT...WITH LIGHTER WINDS OVERNIGHT AND TUESDAY AS
A BUBBLE HIGH MOVES ACROSS THE AREA BEHIND THE FRONT.
THE HIGH WILL MOVE OFF TO THE EAST WEDNESDAY MORNING...WITH WINDS
BECOMING SOUTH AND STRENGTHENING TO 20-25 KT AGAIN LATER IN THE
WEDNESDAY AND CONTINUING INTO THURSDAY BEFORE THE NEXT SURFACE LOW
PASSES NORTH OF THE LAKES AND ITS TRAILING COLD FRONT MOVES THROUGH
LATE THURSDAY NIGHT AND EARLY FRIDAY. WINDS DONT LOOK TO BE TOO
STRONG IMMEDIATELY BEHIND THIS SECOND FRONT...THOUGH A PERIOD OF
ENHANCED NORTHERLY WINDS IS POSSIBLE SATURDAY AS HIGH PRESSURE
BUILDS IN BEHIND THE FRONT.
WITH GUSTY SOUTH WINDS MONDAY...A SMALL CRAFT ADVISORY HAS BEEN
ISSUED FOR THE ILLINOIS AND INDIANA NEAR SHORE WATERS FROM
MID-MORNING THROUGH MORNING EVENING.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...10 AM MONDAY TO 10 PM MONDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1243 PM CDT Sun Aug 31 2014
.UPDATE...
ISSUED AT 948 AM CDT SUN AUG 31 2014
A low overcast persists across much of central Illinois along and
east of a Peoria to Jacksonville line this morning. 1430z visible
satellite imagery is showing thin spots developing in the cloud
cover, so am expecting it to dissipate within the next 2 to 3
hours. HRRR ceiling forecast shows this trend quite nicely,
resulting in a partly to mostly sunny afternoon. May see a few
showers/thunder pop up along/south of I-70: however, areal
coverage will remain spotty. Updated the forecast to better
reflect sky cover trends this morning and to confine PoPs to just
the far SE KILX CWA.
&&
.SHORT TERM...(Today and tonight)
ISSUED AT 358 AM CDT SUN AUG 31 2014
Shortwave trough and jet entrance region that brought banded
convection and some locally heavy precipitation to central IL last
evening has shifted northeastward with shower activity nearly ended
over the ILX CWA. With clearing skies and good radiational cooling,
patchy fog will continue to form overnight, mainly I-55
westward.
Moist conditions with enough instability will remain through the
afternoon today for a few showers and thunderstorms, mainly I-70
southeastward, but a relatively dry day expected. Highs in the mid
80s are expected.
After sunset, convection should end quickly across the CWA with the
loss of surface heating. Late in the night, chances for
thunderstorms will spread back into west central Illinois as another
cold front approaches from the west.
&&
.LONG TERM...(Monday through Saturday)
ISSUED AT 358 AM CDT SUN AUG 31 2014
SPC continues a slight risk (15+%) of severe thunderstorms across
central IL nw of a Flora to Robinson line Monday afternoon/evening
for damaging winds and large hail. This seems reasonable considering
surface to 6 km bulk shear values of 30-40 kts, CAPES of 2-3k J/kg.
Heavy rains also possible with thunderstorms in tropical airmass
ahead of frontal boundary. Short waves and 30-40 kt low level jet
moving into IL river valley later Sunday night into Monday morning
and then spreading into eastern IL Monday afternoon/evening. Upper
level trof over northern Rockies moves east into Midwest
Monday/Monday night and drives a cold front southeast across central
IL Monday night. Continued likely pops across much of area Monday
afternoon into Monday night, though diminishing pops overnight
Monday night nw of IL river. Best chances of showers and
thunderstorms lingers over areas from I-72 south on Tue especially
in the morning. The 5% risk of severe storms Tue is southeast of
Lawrenceville. Quite warm and humid Monday ahead of front with highs
82-88F and dewpoints 70-75F and warmest temps in southeast IL where
rain arrives later.
Frontal boundary to weaken as it moves se into Ohio River valley
Tue/Wed with near zonal upper level flow over the region. Carried
just slight chance of convection during midweek from Tue night
through Thu night. Highs in the low to mid 80s Tue/Wed climb into
mid 80s to around 90F Thu/Fri as dewpoints rise back into the low to
mid 70s with heat indices approaching 100F southern counties Thu/Fri
afternoon. Next frontal boundary press southeast into IL Friday
afternoon into Sat and bringing next best chances of showers and
thunderstorms and cooler temps during next weekend.
&&
.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
ISSUED AT 1243 PM CDT SUN AUG 31 2014
MVFR ceilings will persist at the central Illinois terminals for
the next hour or two before gradually dissipating as the afternoon
progresses. Based on satellite trends, have scattered ceilings at
most sites by 19z, then at KDEC and KBMI by 20z. After that,
mostly clear skies will prevail through the evening before clouds
begin to increase from the west late tonight. A thunderstorm
complex currently developing across western Iowa/Nebraska will
track eastward tonight, with most model guidance keeping it west
of the Illinois River until 12z. Think storms will arrive in the
Illinois River Valley toward dawn in a weakening state, then
spread eastward across the area Monday morning. Have therefore
introduced low VFR ceilings and VCTS at KPIA after 12z, then
further east to KBMI and KDEC after 14/15z. Given plenty of
low-level moisture and relatively light winds, included slightly
reduced visbys down to 4sm at KCMI where skies will remain mostly
clear through dawn. Further west, think increasing clouds and wind
will prevent fog formation.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BARNES
SHORT TERM...ONTON
LONG TERM...07
AVIATION...BARNES
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1108 AM CDT SUN AUG 31 2014
.DISCUSSION...
328 AM CDT
AFTER A FAIRLY QUIET DAY ACROSS THE AREA TODAY...ATTENTION QUICKLY
SHIFTS TO THE WEATHER FOR LABOR DAY INTO MONDAY NIGHT...DURING WHICH
PERIODS OF EXTREMELY HEAVY RAINFALL AND SEVERE WEATHER ARE POSSIBLE.
THUNDERSTORMS CONTINUED TO TRAIN ACROSS THE SAME AREAS ACROSS
PORTIONS OF FORD AND IROQUOIS COUNTIES IN ILLINOIS AND ALSO BENTON
COUNTY IN INDIANA YESTERDAY EVENING AND INTO THE OVERNIGHT HOURS.
THESE AREAS LIED IN THE RIGHT ENTRANCE REGION OF AN UPPER LEVEL JET
STREAK. THE COMBINATION OF THIS...AND THE CONTINUED LOW LEVEL
CONFLUENCE CONTINUED TO DRIVE THIS CONVECTION. RADAR ESTIMATES SOME
VERY HEFTY ISOLATED RAINFALL AMOUNTS IN EXCESS OF 4 INCHES ACROSS
PORTIONS OF THESE COUNTIES. ALTHOUGH SOME ISOLATED ACTIVITY
CONTINUES ACROSS THIS AREA AS OF THIS WRITING...IT IS EXPECTED THAT
ALL THIS ACTIVITY WILL SHIFT OUT OF THE AREA AROUND...OR JUST PRIOR
TO DAYBREAK AS THE UPPER LEVEL JET DEVELOPS EASTWARD.
WATER VAPOR IMAGERY EARLY THIS MORNING SHOWS THE NEXT UPPER LEVEL
SYSTEM CURRENTLY DIGGING ACROSS THE ROCKIES. AIRCRAFT AND UPPER AIR
OBSERVATIONS ACROSS WESTERN CANADA AND OVER THE NORTHEAST PACIFIC
INDICATE SOME IMPRESSIVE UPPER LEVEL WINDS...FOR THIS TIME OF
YEAR...IN EXCESS OF 110 KT WITHIN THE CORE OF THE JET STREAK
DIGGING OVER THE WESTERN CONUS. THE FIRST MID LEVEL IMPULSE IS
EXPECTED TO CONTINUE SHIFTING EASTWARD OVER THE UPPER MIDWEST INTO
MONDAY MORNING. AS IT DOES SO...IT WILL DRIVE A FAIRLY STOUT
SURFACE LOW NORTHEASTWARD FROM THE DAKOTAS TO ONTARIO. SOME VERY
SUBSTANTIAL CONVECTION IS EXPECTED TO DEVELOP AHEAD OF THE COLD
FRONT LATER TODAY ACROSS PORTIONS OF THE MID MISSOURI VALLEY AND
INTO MINNESOTA. THIS ACTIVITY WILL LIKELY SHIFT EAST-NORTHEASTWARD
OVERNIGHT TONIGHT...WITH SOME OF THE REMNANT ACTIVITY POSSIBLY
REACHING NORTH CENTRAL ILLINOIS BY AROUND...OR JUST PRIOR TO
DAYBREAK MONDAY. IT APPEARS THAT THIS INITIAL ROUND OF CONVECTION
COULD BE IN A WEAKENING PHASE AS IT TRIES TO PUSH OVER PORTIONS
OF NORTHERN ILLINOIS MONDAY MORNING. HOWEVER...RENEWED CONVECTIVE
DEVELOPMENT...POSSIBLY ALONG ANY OUTFLOW BOUNDARIES LAID DOWN BY
EARLY MORNING ACTIVITY...IS LIKELY ACROSS PORTIONS OF NORTHEASTERN
ILLINOIS AND NORTHWESTERN INDIANA BY MONDAY AFTERNOON.
MODEL SOUNDINGS ALL INDICATE FAVORABLE PROFILES FOR ACTIVE STRONG TO
SEVERE STORMS OVER THE AREA DURING THE AFTERNOON AND EARLY EVENING
MONDAY. DEEP LAYER BULK SHEAR LOOKS TO BE SOMEWHAT
UNIDIRECTIONAL...BUT WITH 0-6 KM SPEED SHEAR OF NEARLY 50
KT...ORGANIZED CONVECTIVE ACTIVITY APPEARS VERY POSSIBLE. THE MAIN
COMPLICATING FACTOR AT THIS POINT IS HOW MUCH ANY CLOUD DEBRIS OR
REMNANT MORNING CONVECTIVE ACTIVITY IMPACTS AFTERNOON HEATING AND
DESTABILIZATION ACROSS NORTHEASTERN ILLINOIS AND NORTHWESTERN
INDIANA. HOWEVER...IN SPITE OF THIS POSSIBILITY EARLY IN THE
DAY...IT DOES APPEAR THAT THE HIGH THETA E NEAR SURFACE AIR MASS
SHOULD BE ENOUGH TO PRODUCE AMPLE MLCAPE VALUES AT OR JUST IN
EXCESS OF 1500 J/KG...WHICH COMBINED WITH THE 45+ DEEP LAYER SHEAR
CERTAINLY POINTS TO A SEVERE THREAT. AT THIS TIME IT APPEARS
RATHER MODEST MID LEVEL LAPSE RATES WOULD RESULT IN THE MAIN
SEVERE THREAT BEING STRONG DAMAGING WIND GUSTS. HOWEVER...THERE IS
ALSO A SECONDARY THREAT OF LARGE HAIL...ESPECIALLY IF ANY SUPER
CELLS CAN FORM.
THERE IS ALSO A DECENT CONCERN FOR EXTREMELY HEAVY RAINFALL RATES
WITH THESE STORMS...WITH PWAT VALUES IN THIS JUICY ENVIRONMENT
LIKELY TO RESIDE AROUND 1.7 INCHES. NUMERICAL GUIDANCE CONTINUES TO
SUGGEST THAT A SECONDARY MID LEVEL IMPULSE WILL APPROACH THE AREA
MONDAY NIGHT AND ACT TO INDUCE/STRENGTHEN A SOUTHWESTERLY UPPER
LEVEL JET STREAK ACROSS THE GREAT LAKES REGION INTO MONDAY NIGHT.
THIS PROCESS COULD SET UP PORTIONS OF THE AREA WITHIN THE FAVORABLE
RIGHT ENTRANCE REGION OF A 100 KT UPPER LEVEL JET INTO TUESDAY
MORNING AS THE SURFACE COLD FRONTAL BOUNDARY SLOWLY TRIES TO SHIFT
SOUTHWARD ACROSS THE SOUTHERN HALF OF MY CWA. I HAVE INCREASING
CONCERNS THAT THIS COULD SET UP A VERY HEAVY RAIN EVENT MONDAY
NIGHT...WITH STORMS POTENTIALLY TRAINING TO THE EAST NORTHEAST
NEARLY PARALLEL TO THE SURFACE BOUNDARY. AT THIS TIME IT APPEARS THIS
HEAVY RAIN THREAT COULD END UP SOUTH OF INTERSTATE 80 MONDAY NIGHT.
HOWEVER...UNCERTAINTY IS STILL A BIT HIGH AS TO HOW FAR SOUTH THE
SURFACE FRONT WILL GET MONDAY NIGHT...AND HENCE WHERE THE MOST
FAVORED AREAS FOR TRAINING CELLS WILL OCCUR. AT THIS POINT...I HAVE
ADDED HEAVY RAIN WORDING TO THE FORECAST...MAINLY FOR AREAS SOUTH OF
INTERSTATE 80 INTO MONDAY NIGHT.
FOLLOWING THIS ACTIVE WEATHER MONDAY NIGHT IT APPEARS THE WEATHER
WILL BE DRY FOR THE MOST PART THROUGH LATE WEEK. THE MAIN STORY
HOWEVER...WILL BE THE INCREASING HEAT BY THURSDAY. FORECAST GUIDANCE
CONTINUES TO FORECAST MID LEVEL HEIGHTS TO BUILD SUBSTANTIALLY
ACROSS THE CENTRAL CONUS. THIS COULD LEAD TO A RUN AT
90 TEMPERATURES FOR THURSDAY AS 850 MB TEMPERATURES WARM TO 20 TO
22C. I HAVE STARTED CUTTING BACK ON THE SLIGHT CHANCE
POPS...ESPECIALLY ON WEDNESDAY AND WEDNESDAY NIGHT...BUT LEFT IN
SOME SLIGHTS FOR THURSDAY. ALTHOUGH SOME ISOLATED CONVECTIVE
ACTIVITY IS POSSIBLE DURING THIS TIME...IT APPEARS THAT THE BUILDING
HEIGHTS AND WARMING TEMPS ALOFT COULD END UP CAPPING THE AREA...AND
LIMITING THE THREAT FOR CONVECTIVE DEVELOPMENT THROUGH THURSDAY.
CONVECTIVE CHANCES DO LOOK TO RETURN TO THE AREA AGAIN BY FRIDAY.
ANOTHER SIGNIFICANT WAVE IS EXPECTED TO SHIFT EASTWARD ACROSS THE
NORTHERN CONUS AND SOUTHERN CANADA LATE IN THE PERIOD...AND THIS
LOOKS TO SHIFT A COLD FRONT SOUTHWARD ACROSS THE AREA SOMETIME
EITHER FRIDAY OR FRIDAY NIGHT AND THIS COULD SPARK OFF ACTIVITY
ACROSS THE AREA. COOLER WEATHER DOES LOOK TO OVERSPREAD TO AREA
UNDER NORTHERLY WINDS BY EARLY NEXT WEEKEND.
KJB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* CHANCE FOR A LAKE BREEZE/WIND SHIFT TO EASTERLY LATE SUNDAY
AFTERNOON.
KREIN/BMD
//DISCUSSION...UPDATED 12Z...
AS THE CLOUD SHIELD CLEARS OUT AND WITH CALM WINDS AND RESIDUAL
LOW LEVEL MOISTURE IN PLACE...SOME PATCHY FOG/STRATUS HAS
DEVELOPED. HOWEVER...WITH AMPLE SUNSHINE...EXPECT THAT THE
FOG/STRATUS WILL QUICKLY DISSIPATE BY MID MORNING WITH VFR
CONDITIONS EXPECTED THE REMAINDER OF THE DAY. WINDS SHOULD REMAIN
LIGHT ENOUGH TO ALLOW A LAKE BREEZE TO DEVELOP...BUT THERE APPEARS
TO BE LITTLE PUSH BEHIND THE BOUNDARY...SO AT THIS POINT...FEEL
THAT CHANCES ARE LOW THAT THE LAKE BREEZE WILL PUSH INLAND OF
ORD/MDW. HOWEVER...IF THE LAKE BREEZE DOES MANAGE TO PUSH WEST OF
ORD/MDW...IT WOULD NOT BE UNTIL ARND 22-23Z AND ELY WINDS WOULD BE
ARND 5-7KT. ANOTHER APPROACHING COLD FRONT WILL BRING INCREASING
CHANCES FOR MORE SHOWERS AND THUNDERSTORMS BUT THIS WILL LIKELY
NOT BE UNTIL AFTER 12Z TOMORROW.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* MEDIUM TO HIGH CONFIDENCE IN LAKE BREEZE SUNDAY AFTERNOON...AND
MEDIUM CONFIDENCE THAT THE BOUNDARY WILL NOT PUSH THROUGH
ORD/MDW.
* LOW CONFIDENCE IN TIMING TS TOMORROW.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
KREIN/BMD
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...CHANCE SHRA/TSRA.
TUESDAY AND WEDNESDAY...VFR. WX NIL.
THURSDAY THROUGH SATURDAY...PERIODIC CHANCES FOR SHRA/TSRA.
KREIN
&&
.MARINE...
300 AM CDT
A PERIOD OF CHANGEABLE WEATHER...IN PARTICULAR...WIND
DIRECTION...IS SETTING UP FOR THE NEXT SEVERAL DAYS. LOW PRESSURE
JUST NORTH OF GEORGIAN BAY WILL TRACK EAST TO SOUTHERN QUEBEC BY
LATE SUNDAY MORNING WHILE DRAGGING A WEAK COLD FRONT SOUTH ACROSS
THE LAKE AND CLEARING THE SOUTH END OF LAKE MICHIGAN BY EARLY
SUNDAY. THIS WILL SET UP A BRIEF PERIOD OF NWLY WINDS...BUT AS
HIGH PRESSURE BUILDS OVER THE NORTHERN LAKES BEHIND THE FRONT
SUNDAY AFTERNOON WINDS WILL BECOME LGT/VRBL FOR A SHORT TIME.
SLY FLOW WILL RETURN TO THE LAKE SUNDAY NIGHT AND
MONDAY...STRENGTHENING TO ARND 25KT AS ANOTHER LOW DEVELOPING OVER
THE NORTHERN PLAINS DEEPENS WHILE TRACKING TO HUDSON BAY MONDAY
NIGHT. THIS LOW WILL DRAG ANOTHER COLD FRONT SOUTH ACROSS LAKE
MICHIGAN MONDAY NIGHT. WEAK HIGH PRESSURE WILL BUILD ACROSS THE
LAKE TUESDAY BRINGING ANOTHER PERIOD OF LIGHT WINDS. BUT YET
ANOTHER LOW IS EXPECTED TO MOVE OUT OF THE NORTHERN ROCKIES AND
INTO THE NORTHERN PLAINS WEDNESDAY NIGHT...BRINGING ANOTHER PERIOD
OF BRISK SOUTH WINDS TO THE LAKE FOR WEDNESDAY AND THURSDAY. THIS
LOW IS FORECAST TO TRACK TO NEAR THE SOUTHERN TIP OF JAMES BAY
DRAGGING ANOTHER COLD FRONT ACROSS THE LAKE FRIDAY OR FRIDAY
NIGHT. ACCOMPANYING THESE FRONTAL PASSAGES WILL ALSO BE PERIODS OF
THUNDERSTORMS AS WELL.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
948 AM CDT Sun Aug 31 2014
.UPDATE...
ISSUED AT 948 AM CDT SUN AUG 31 2014
A low overcast persists across much of central Illinois along and
east of a Peoria to Jacksonville line this morning. 1430z visible
satellite imagery is showing thin spots developing in the cloud
cover, so am expecting it to dissipate within the next 2 to 3
hours. HRRR ceiling forecast shows this trend quite nicely,
resulting in a partly to mostly sunny afternoon. May see a few
showers/thunder pop up along/south of I-70: however, areal
coverage will remain spotty. Updated the forecast to better
reflect sky cover trends this morning and to confine PoPs to just
the far SE KILX CWA.
&&
.SHORT TERM...(Today and tonight)
ISSUED AT 358 AM CDT SUN AUG 31 2014
Shortwave trough and jet entrance region that brought banded
convection and some locally heavy precipitation to central IL last
evening has shifted northeastward with shower activity nearly ended
over the ILX CWA. With clearing skies and good radiational cooling,
patchy fog will continue to form overnight, mainly I-55
westward.
Moist conditions with enough instability will remain through the
afternoon today for a few showers and thunderstorms, mainly I-70
southeastward, but a relatively dry day expected. Highs in the mid
80s are expected.
After sunset, convection should end quickly across the CWA with the
loss of surface heating. Late in the night, chances for
thunderstorms will spread back into west central Illinois as another
cold front approaches from the west.
&&
.LONG TERM...(Monday through Saturday)
ISSUED AT 358 AM CDT SUN AUG 31 2014
SPC continues a slight risk (15+%) of severe thunderstorms across
central IL nw of a Flora to Robinson line Monday afternoon/evening
for damaging winds and large hail. This seems reasonable considering
surface to 6 km bulk shear values of 30-40 kts, CAPES of 2-3k J/kg.
Heavy rains also possible with thunderstorms in tropical airmass
ahead of frontal boundary. Short waves and 30-40 kt low level jet
moving into IL river valley later Sunday night into Monday morning
and then spreading into eastern IL Monday afternoon/evening. Upper
level trof over northern Rockies moves east into Midwest
Monday/Monday night and drives a cold front southeast across central
IL Monday night. Continued likely pops across much of area Monday
afternoon into Monday night, though diminishing pops overnight
Monday night nw of IL river. Best chances of showers and
thunderstorms lingers over areas from I-72 south on Tue especially
in the morning. The 5% risk of severe storms Tue is southeast of
Lawrenceville. Quite warm and humid Monday ahead of front with highs
82-88F and dewpoints 70-75F and warmest temps in southeast IL where
rain arrives later.
Frontal boundary to weaken as it moves se into Ohio River valley
Tue/Wed with near zonal upper level flow over the region. Carried
just slight chance of convection during midweek from Tue night
through Thu night. Highs in the low to mid 80s Tue/Wed climb into
mid 80s to around 90F Thu/Fri as dewpoints rise back into the low to
mid 70s with heat indices approaching 100F southern counties Thu/Fri
afternoon. Next frontal boundary press southeast into IL Friday
afternoon into Sat and bringing next best chances of showers and
thunderstorms and cooler temps during next weekend.
&&
.AVIATION...(For the 12Z TAFS through 12Z Monday morning)
ISSUED AT 656 AM CDT SUN AUG 31 2014
Mainly IFR/MVFR visibilities this morning due to low ceilings and
areas of fog. Expect improving conditions through 14Z with
conditions generally becoming VFR as surface heating lifts
ceilings and dissipates fog. Isold TSRA to continue until around
00Z mainly K1H2-KPRG southward with potential MVFR cig/vsby and
gusty winds. After 00Z...TSRA ending with VFR conditions across
central/SE Illinois. Toward 12Z Monday...potential TSRA
development KIJX-KPIA westward depending on speed of approaching
system, but probability of TSRA and associated flight category
reductions too low probability before 12Z for mention in TAFS at
this time.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BARNES
SHORT TERM...ONTON
LONG TERM...07
AVIATION...ONTON
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
314 PM CDT SUN AUG 31 2014
.SYNOPSIS...
ISSUED AT 313 PM CDT SUN AUG 31 2014
A WARM...MID SUMMER-LIKE DAY IS FOUND OVER OUR CWA TODAY AS WE
REMAIN WELL EAST OF THE COLD FRONT APPROACHING IOWA THIS AFTERNOON.
THE COLD FRONT IS SLOWLY MOVING EAST...AND HAS ALREADY SPAWNED A FEW
HIGH BASED THUNDERSTORMS FROM SOUTHERN MN TO FAR EASTERN NE.
TEMPERATURES WITH FULL SUN TODAY HAVE REACHED THE MID 80S AS OF 2
PM...AND APPEAR SET FOR HIGHS IN THE MID TO UPPER 80S BEFORE CLOUDS
INTERRUPT THE HEATING LATER THIS AFTERNOON. SURFACE BASED STORMS
REMAIN CAPPED FOR NOW...THOUGH CAPE VALUES ARE SHOWN ON RAP DATA TO BE
2000 TO 4000 J/KG.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 313 PM CDT SUN AUG 31 2014
THERE IS LITTLE DOUBT THERE WILL BE AN IMPRESSIVE CONVECTIVE EVENT
TONIGHT. THERE IS PLENTY OF DOUBT THAT IT WILL STRONGLY AFFECT MORE
THAN JUST THE WESTERN MOST PORTION OF OUR CWA. THE SLOW MOVING
FRONT SHOULD BE ENOUGH TO FOCUS STORMS WITH PLENTY OF CAPE AND
MOISTURE AVAILABLE TO THE WEST...LIKELY NEAR THE MISSOURI RIVER.
THEY SHOULD MOVE EAST...SLOWLY. THIS PLACES THE WEAKENING PHASE OF
THE COMPLEX INTO EASTERN IOWA BETWEEN MIDNIGHT AND 9 AM MONDAY. THIS
POOR DIURNAL TIMING COMBINED WITH LESS THAN IDEAL MOISTURE TRANSPORT
DURING THAT TIME FRAME SUGGESTS BOTH INTENSITY AND COVERAGE OF
STORMS WILL BE ON THE WANE IN THAT PERIOD. I HAVE CONFINED HIGH POPS
TO ONLY THE WESTERN CWA LATE TONIGHT...AND LOWERED TO CHANCE FOR
MONDAY MORNING SINCE MOST MODELS SUGGEST A FRAGMENTED LINE...AND
THAT SEEMS MOST LIKELY TO ME AS WELL. QPF SHOULD BE IMPRESSIVE TO
THE WEST...BUT MAY BE INSIGNIFICANT IN OUR CWA...GENERALLY 0.25 OR
LESS IN ALL BE THE FAR WEST...WHERE 0.5 TO 1.0 IS POSSIBLE.
MONDAY WILL SEE FAR BETTER DYNAMICS...THUS THE SPC OUTLOOK FOR
SEVERE WEATHER. HOWEVER...THE CONVERGENT OUTFLOW BOUNDARY WILL
LIKELY BE WELL IN ADVANCE OF THE COLD FRONT...WHICH SHOULD ALSO
DEFLECT THE STRONGEST HEATING WELL EAST OF THE CWA AS WELL.
THUS...THE WEAKENING CONVECTIVE DEBRIS SHOULD INHIBIT OUR MONDAY
SEVERE POTENTIAL...AS WELL AS WIDESPREAD RAIN POTENTIAL AGAIN. SURE
SEEMS THIS EVENT SHOULD PRODUCE THE MAJORITY OF ITS RAIN WEST AND
SOUTHEAST OF OUR CWA.
ERVIN
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 313 PM CDT SUN AUG 31 2014
THE FRONT WILL CLEAR THE SOUTHEAST HALF OF THE AREA LATE MONDAY
EVENING. THE SOUTHEAST HALF OF THE AREA SHOULD SEE PRECIPITATION
ONGOING AT SUNSET THAT ENDS FROM NORTHWEST TO SOUTHEAST AFTER
MIDNIGHT. DRIER AIR MOVING INTO THE AREA SHOULD RESULT IN LOWS NEAR
OR SLIGHTLY BELOW NORMAL BY SUNRISE TUESDAY.
TUESDAY/TUESDAY NIGHT DRY CONDITIONS ARE EXPECTED AS HIGH PRESSURE
MOVES THROUGH THE MIDWEST. TEMPERATURES SHOULD BE CLOSE TO NORMAL.
WEDNESDAY MORNING LOOKS TO BE DRY ACROSS THE AREA AS THE HIGH MOVES
TOWARD THE EAST COAST. A WEAK DISTURBANCE WILL MOVE THROUGH THE AREA
WEDNESDAY AFTERNOON. THE OVERALL FORCING IS NOT STRONG AND MOISTURE
AVAILABILITY IS IN QUESTION. IF PRECIPITATION DOES OCCUR IT WOULD BE
ISOLATED IN NATURE WITH THE SOUTH HALF BEING FAVORED.
WEDNESDAY NIGHT ON...
THE MODEL CONSENSUS HAS SLIGHT CHANCE TO CHANCE POPS IN EACH 12 HR
PERIOD FROM WEDNESDAY NIGHT THROUGH SATURDAY.
THERE IS A WEAK DISTURBANCE MOVING THROUGH THE AREA WEDNESDAY
NIGHT/THURSDAY. MOISTURE AVAILABILITY WILL BE ON THE INCREASE BUT
THE OVERALL FORCING IS NOT STRONG. THE POSSIBILITY DOES EXIST THERE
WILL BE PERIODS OF DRY WEATHER WEDNESDAY NIGHT/THURSDAY.
THE MODELS DIFFER SOMEWHAT ON THE TIMING BUT AGREE THAT ANOTHER COLD
FRONT WILL MOVE THROUGH THE AREA IN THE THURSDAY NIGHT THROUGH
FRIDAY NIGHT TIME FRAME.
SEVERAL MODELS ARE PUSHING A SIGNIFICANT HIGH INTO THE WESTERN GREAT
LAKES ON SATURDAY. THE CURRENT MODEL CONSENSUS HAS SLIGHT CHANCE
POPS ACROSS THE SOUTH QUARTER OF THE AREA BUT THE OVERALL TREND IS
SUGGESTING DECREASING PRECIPITATION CHANCES.
SATURDAY NIGHT THROUGH SUNDAY THE MODEL CONSENSUS HAS DRY CONDITIONS
WITH HIGH PRESSURE OVER THE GREAT LAKES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1225 PM CDT SUN AUG 31 2014
CLEAR SKIES AND SOUTHERLY WINDS AROUND 12 KTS WILL CONTINUE THIS
AFTERNOON...WITH AN EVENTUAL INCREASE IN MID AND HIGH CLOUDS
TOWARD EVENING AS A COLD FRONT APPROACHES FROM THE WEST. THIS
FRONT WILL BRING WIDESPREAD THUNDERSTORMS TO THE PLAINS...THROUGH
CENTRAL IOWA AND SOUTHERN MINNESOTA THIS AFTERNOON AND EVENING.
HOWEVER...THE LINE OF STORMS SHOULD WEAKEN BELOW SEVERE LEVELS
LATE THIS EVENING AS IT APPROACHES EASTERN IOWA. A PERIOD OF
THUNDERSTORMS AND RAIN IS LIKELY AT DBQ AND CID AS THIS LINE MOVES
EAST. FARTHER SOUTHEAST...THE LINE OF STORMS MAY BREAK UP INTO
SCATTERED SHOWERS...THUS A PROB30 PERIOD OF STORMS IS INCLUDED AT
MLI AND BRL. AFTER STORMS ROLL EAST MONDAY MORNING...A PERIOD OF
MVFR CIGS IS EXPECTED AT ALL SITES.
ERVIN
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...ERVIN
SHORT TERM...ERVIN
LONG TERM...08
AVIATION...ERVIN
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1221 PM CDT SUN AUG 31 2014
...UPDATED AVIATION SECTION...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 333 AM CDT SUN AUG 31 2014
THE HRRR WAS INDICATING A BROKEN LINE OF RELATIVELY LIGHT
REFLECTIVITY MOVING EASTWARD FROM THE AFOREMENTIONED DEVELOPMENT
ZONE INTO CENTRAL KS BY AROUND 10-12 UTC. THIS SOLUTION WAS FOLLOWED
WITH BASICALLY LOW POPS BELOW 20 PERCENT. THE MORE SIGNIFICANT ISSUE
FOR THE DAY WILL BE A LATE DAY OR EVENING SEVERE WEATHER THREAT. THE
NMM AND ARW MODEL RUNS DEVELOPED A QLCS TYPE BOWING SEGMENT ACROSS
NORTHERN KS, ALONG AND AHEAD OF A COLD FRONT/DRYLINE INTERSECTION
OVER NORTHERN KS. FARTHER SOUTH, OVER OUR AREA, ANY CONVECTION IN
THESE SOLUTIONS COULD BE GENERALLY MORE DISCREET AND MORE HIGH BASED
(HAIL AND WIND THREATS POSSIBLE) WITH SUFFICIENT SHEAR FOR
SUPERCELLS. HOWEVER, IT IS POSSIBLE OUTFLOWS/COLD POOLS COULD FORCE
MORE WIDESPREAD DEVELOPMENT FARTHER BRINGING MORE OF OUR AREA
INTO A SEVERE WEATHER THREAT.
SURFACE WINDS WILL BE MORE BREEZY AHEAD OF THE DRYLINE THIS
AFTERNOON. MODELS SUGGEST 15 TO 20 KNOTS SUSTAINED WINDS WILL BE
COMMON WITH GUSTS IN TO JUST UNDER 30 KNOTS. YESTERDAY`S HIGHS OF
LOW 90S TO MID 90S IN THE SOUTHWEST SECTIONS ARE A REASONABLE TELL
FOR HIGHS TODAY. THE LATEST SHORT TERM CONSENSUS SUPPORTS MID 90S
TO NEAR 100 DEGREES IN THE SW GIVEN THE COMBINATION OF SLIGHTLY
DRIER AIR AND BETTER DOWNSLOPE. WITH THE FRONTAL BOUNDARY AND
POTENTIAL MOIST BOUNDARY LAYER OUTFLOW ACROSS THE AREA TONIGHT, A
LARGE GRADIENT OF AROUND 20 DEGREES COULD EXIST FOR OVERNIGHT LOWS
FROM MID 50`S OUT WEST TO MID 70S IN THE PRATT COLDWATER AND
MEDICINE LODGE AREA SETTING AN EARLY MILD LOW JUST AFTER
MIDNIGHT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 414 AM CDT SUN AUG 31 2014
THE FRONT FOLLOWING TONIGHTS STORM SYSTEM WILL REACH THE TEXAS
PANHANDLE AND ADJACENT WESTERN OKLAHOMA BY LATE MONDAY/MONDAY NIGHT.
THE DAYTIME HOURS MONDAY WILL BE FAIRLY TRANQUIL AS SUBSIDENCE WILL
PREVAIL IN THE WAKE OF THE DEPARTING SYSTEM. MODEST TEMPERATURES IN
THE 80S ARE EXPECTED. THE FRONT WILL STALL OUT MONDAY NIGHT AND WE
WILL FIND OURSELVES IN THE RIGHT ENTRANCE REGION OF AN UPPER
TROPOSPHERIC JET. THIS WILL ENHANCE FRONTOGENESIS IN THE 900-800MB
LAYER, SUPPORTING NOCTURNAL THUNDERSTORMS ONCE THE LOW LEVEL JET
DEVELOPS. THE MOST FAVORABLE LOCATION FOR MONDAY NIGHT/EARLY TUESDAY
STORMS WILL BE ACROSS SOUTH CENTRAL KANSAS, WHICH IS WHERE WE WILL
HAVE THE HIGHEST CHANCE POPS (AROUND 40 PERCENT). THIS FRONTAL ZONE
WILL NOT MOVE TUESDAY, AND WE WILL NEED TO CARRY SOME CHANCE POPS
THROUGH THE DAY ACROSS SOUTH CENTRAL KANSAS. DAYTIME TEMPERATURES
WILL BE AT OR JUST SLIGHTLY ABOVE AVERAGE FOR THE FIRST PART OF
SEPTEMBER (MID TO UPPER 80S AS A RULE). THE FRONT WILL EVENTUALLY
DISSOLVE BY LATE TUESDAY NIGHT AND ESPECIALLY BY WEDNESDAY, AS THE
LOW LEVEL FLOW FIELD BEGINS TO RESPOND TO LOWER PRESSURE MUCH
FARTHER NORTH WHERE THE POLAR JET WILL BE LOCATED. THE NEXT STORM
SYSTEM MID-WEEK WILL BE MUCH FARTHER NORTH WITH WEAK ZONAL FLOW
ACROSS COLORADO AND KANSAS FOR THE MOST PART. THIS WILL LEAD TO
WARMER TEMPERATURES AND DRIER WEATHER. WEDNESDAY AND THURSDAY
CONTINUE TO LOOK LIKE THE HOTTEST DAYS NEXT WEEK WITH AFTERNOON
HIGHS IN THE 95-100F RANGE FOR MUCH OF WESTERN AND SOUTHERN KANSAS.
THE NORTHERN POLAR JET STORM SYSTEM THAT WAS MENTIONED WILL MOVE
EAST ACROSS THE NORTHERN GREAT PLAINS/ADJACENT CANADIAN PRAIRIES
LATE IN THE WEEK, USHERING IN SOME MUCH COOLER TEMPERATURES ACROSS
THE NORTHERN PLAINS. THIS AIRMASS WILL LIKELY REACH KANSAS BY END OF
WEEK AND INTO THE WEEKEND. THERE APPEARS TO BE A FAIRLY STRONG
SIGNAL OF COOLER/WETTER WEATHER SEPTEMBER 6-8 TIME FRAME.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1216 PM CDT SUN AUG 31 2014
A DRYLINE WILL SET UP BETWEEN THE GCK AND DDC TERMINAL THIS
AFTERNOON WITH SOUTH SOUTHWEST WINDS FELT ACROSS THE GCK TERMINAL AND
SOUTH TO SOUTH SOUTHEAST WINDS FELT AT THE HYS AND DDC TERMINALS. BREEZY
CONDITIONS WILL ALSO OCCUR ACROSS THE TAF SITES THIS AFTERNOON WITH
SUSTAINED WINDS ABOVE 20 KNOTS AND GUSTS ABOVE 30 KNOTS. WINDS
THEN DIE DOWN THIS EVENING BEFORE BECOMING LIGHT AND VARIABLE
OVERNIGHT. A FEW THUNDERSTORMS MAY DEVELOP ACROSS THE HYS AND DDC
TERMINALS EARLY THIS EVENING BRIEFLY REDUCING VISIBILITIES AND
CEILINGS. I HAVE PLACED A TEMPO GROUP IN THE TAFS TO REFLECT THIS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 99 65 87 65 / 50 30 10 30
GCK 100 62 87 63 / 20 30 10 20
EHA 100 62 91 63 / 10 10 10 10
LBL 103 65 91 64 / 10 20 10 20
HYS 97 64 84 63 / 50 60 20 20
P28 99 71 90 70 / 10 20 20 50
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...RUSSELL
LONG TERM...UMSCHEID
AVIATION...HOVORKA_42
AREA FORECAST DISCUSSION
NWS PADUCAH KY
238 PM CDT Sun Aug 31 2014
.SHORT TERM...(Tonight through Tuesday night)
Issued at 238 PM CDT SUN AUG 31 2014
Wvapor and RAP data shows subtle mid level wave moving slowly
east across the area. Convection near SEMO making little eastward
progress. Tiny showers over west KY moving east as well. Will keep
PoPs limited through the early evening before ending them from
west to east overnight. Frontal boundary will approach the area
Monday night. Best chance of activity will be over far north and
west sections of the area. Cannot rule out isolated anywhere, but
chances too low down into west KY to include for now. Moisture is
increasingly limited south of the Ohio. PoPs will rise from NW to
SE Monday night as the front settles south toward the area. Again
best chances north, lowering south. Tuesday the front will stall
somewhere across the area, with upper level support moving across
the region. Thus the chance of convection continues. We could see
some strong storms Tuesday given degree of forecast instability,
and an uptick in the mean flow 850-500mb. Tuesday night we will
drop off PoPs in the wake of the upper system. However more
activity could move into or toward SEMO toward daybreak Wednesday.
Temps will be a blend of existing numbers and the latest blend of
raw model output.
.LONG TERM...(Wednesday through Sunday)
Issued at 238 PM CDT SUN AUG 31 2014
By Wednesday morning, whatever is left of the frontal boundary that
went through the area the night before, will be situated somewhere
over our southern counties. The front will be lifting back north as
a warm front and this is seen most evidently in the theta e fields.
This rebounding front along with minor perturbations in the zonal
flow aloft will likely lead to some convection, especially given the
decent mid level lapse rates, sfc instability parameters and deep
moisture. The upper wave will move off to the east Wednesday night
and things should be fairly quiet except for some possible lingering
afternoon convection.
On Thursday, the upper ridge really begins building over the region
and become centered over us by the end of the day. This should help
boost temperatures up a degree or two into the lower 90s. We should
not see widespread chances for storms though on Thursday, but it
appears as though a small chance will remain, with the best chances
in the east where the better moisture will be confined. Meanwhile, a
frontal boundary will be progressing eastward across the upper
Midwest down into the Central Plains. This front will be slow to
move and models have not been handling its speed very well. Todays
runs of the GFS and ECMWF show a faster progression and have the
front into the area by Friday or Friday night. The best moisture and
QPF is behind the actual front so precipitation chances ramp up by
Friday night into Saturday.
Beyond Saturday, models were having a rough time resolving how
quickly the moisture gets shoved out of the area and this is due to
the differences in the strength and progression of the sfc high
originating from the north central plains states. But the 12Z model
runs of the GFS and ECMWF have finally aligned well and believe that
Sunday (and even Saturday night) should be dry now. In fact, much
drier and cooler air settling in with highs probably in the 70s on
Sunday.
&&
.AVIATION...
Issued at 238 PM CDT SUN AUG 31 2014
Conditions continue to improve given diurnal aspect and with deeper
moisture heading east. Will linger mainly VFR Cu through the end
of the day, with any pockets of MVFR east of a KEVV to KCEY line
giving way to VFR. Chance of convection too low to include at any
of the Terminals. Not too concerned with fog tonight. Cannot rule
out some low cloud development based on moisture transport of
respectable moisture still across the area below 4k/ft. Wind
should stay up enough to preclude a real fog concern. SSW winds
will pick up mid morning Labor day, 10 kts or so, with some CU
expected.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS JACKSON KY
130 PM EDT SUN AUG 31 2014
.UPDATE...
ISSUED AT 130 PM EDT SUN AUG 31 2014
UPDATED THE FORECAST GRIDS AND FLASH FLOOD WATCH EARLIER THIS
AFTERNOON. SHOWERS AND STORMS ARE ONGOING ACROSS THE AREA...WITH NEW
ACTIVITY BEGINNING TO POP UP IN CENTRAL TENNESSEE AND ALABAMA. AFTER
A LULL IN ACTIVITY...NUMEROUS SHOWERS AND STORMS ARE EXPECTED TO MOVE
BACK INTO THE AREA LATER THIS AFTERNOON INTO THIS EVENING. THE FLASH
FLOOD WATCH IS GOOD UNTIL 6 PM TODAY. WILL CONTINUE TO MONITOR THE
SITUATION TO SEE WHETHER OR NOT WE CAN SHAVE SOME COUNTIES OFF OR
CANCEL IT ALTOGETHER BY THE 4 PM AFTERNOON FORECAST PACKAGE ISSUANCE.
THE FORECAST IS PRETTY MUCH ON TRACK FOR THE DAY SO NO MAJOR CHANGES
HAVE BEEN PLANNED AS OF YET.
UPDATE ISSUED AT 720 AM EDT SUN AUG 31 2014
THE BAND OF RAIN OVER CENTRAL KY IS GRADUALLY WORKING INTO EASTERN
KY. ACTIVITY OVER THE NEXT FEW HOURS SHOULD MAINLY BE ACROSS THE
WESTERN AND NORTHWESTERN LOCATIONS. ACTIVITY SHOULD INCREASE IN
INTENSITY FROM MIDDAY INTO THE AFTERNOON HOURS AND LOCALLY HEAVY RAIN
WILL BE POSSIBLE GIVEN THE VERY MOIST AIR MASS IN PLACE ACROSS THE REGION.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 335 AM EDT SUN AUG 31 2014
EARLY THIS MORNING...THE REGION REMAINED IN A VERY MOIST AIR MASS
WITH PW OF 2 INCHES OR MORE EXTENDING INTO THE OHIO VALLEY REGION
BETWEEN A RIDGE OF HIGH PRESSURE CENTERED OFF THE SOUTHEAST US COAST
AND A SHORTWAVE TROUGH EXTENDING SOUTH FROM THE GREAT LAKES INTO THE
MS VALLEY REGION. A LULL IN THE SHOWER AND THUNDERSTORM ACTIVITY IS
WORKING NORTH AND NORTHEAST ACROSS THE CWA ATTM AS THE FIRST WAVE IS
BEGINNING TO DEPART. HOWEVER...THE NEXT WAVE IS WORKING INTO THE MID
MS AND LOWER OH VALLEY REGION AS THE DEEP MOISTURE PLUME REMAINS.
OVER THE NEXT COUPLE OF DAYS...THE INITIAL WAVE WILL DEPART TO THE
NORTH AND NORTHEAST...BUT THE NEXT MOST EVIDENT AT THE 850 MB AND 700
MB LEVEL IS EXPECTED TO TRACK EAST NORTHEAST ACROSS THE OH VALLEY
REGION TODAY. THIS SYSTEM SHOULD ONCE AGAIN INTERACT WITH THE DEEP
MOISTURE PLUME IN PLACE ACROSS THE REGION AND LEAD TO RENEWED
CONVECTIVE ACTIVITY TO OUR WEST GRADUALLY TRANSITIONING INTO EASTERN KY
LATER TONIGHT AND INTO THE DAY ON SUNDAY. THIS SYSTEM WILL DEPART TO
THE NORTH AND EAST TONIGHT. THE SOUTHEASTERN RIDGE IS EXPECTED TO
FLATTEN BY TONIGHT AND INTO MONDAY. THE NEXT TROUGH WILL HAVE MOVED
INTO THE UPPER MS VALLEY REGION AND PLAINS FROM THE ROCKIES BY LATE
TONIGHT...WITH THIS TROUGH WORKING INTO THE GREAT LAKES AND
APPROACHING THE LOWER OH VALLEY REGION LATE IN THE PERIOD. THE
ASSOCIATED SFC COLD FRONT IS ALSO EXPECTED TO APPROACH THE LOWER OH
VALLEY REGION LATE IN THE PERIOD...BUT WILL HAVE MORE OF AN EFFECT ON
THE LONG TERM PORTION OF THE FORECAST.
RECENT HRRR RUNS BRING THE STRONGEST ACTIVITY ACROSS THE REGION
DURING THE AFTERNOON INTO THE EARLY EVENING ON SUNDAY. THIS ACTIVITY
SHOULD BE EFFICIENT RAIN PRODUCERS AND WHERE ANY TRAINING OCCURS
LOCALLY HEAVY RAIN AND FLASH FLOODING WILL BE POSSIBLE. A FLASH FLOOD
WATCH IS ALREADY IN PLACE ACROSS WESTERN AND NORTHWESTERN PARTS OF
THE CWA ATTM AND WE PLAN TO KEEP IT IN PLACE WITH NO CHANGES. LATER
SHIFTS MAY WANT TO CONSIDER EXTENDING IT FURTHER SOUTH AND EAST...BUT
RAINFALL OVER THE PAST 24 HOURS HAS BEEN GENERALLY LIGHTER THERE
COMPARED TO THE SOUTHWESTERN PART OF THE CWA WHERE RADAR ESTIMATES
AND RAIN GAGES INDICATE THAT UPWARDS OF 2 INCHES OR MORE HAS FALLEN
ACROSS PARTS OF WAYNE COUNTY AND FROM MCCREARY COUNTY NORTHEAST INTO
LAUREL COUNTY. TEMPERATURES TODAY SHOULD BE SUPPRESSED BELOW
SATURDAYS LEVELS BY THE ANTICIPATED CLOUD COVER AND PRECIPITATION.
LOCALLY HEAVY RAIN WILL BE MENTIONED IN THE HWO OUTSIDE OF LOCATIONS
CURRENTLY IN THE FLASH FLOOD WATCH.
WITH THE WAVE DEPARTING TONIGHT...CHANCES FOR CONVECTION WILL ALSO
DIMINISH. MIN TEMPERATURES WILL REMAIN ON THE MILD SIDE. AT LEAST
PATCHY VALLEY FOG SHOULD DEVELOP...WHERE ANY PARTIAL CLEARING
OCCURS. ON MONDAY...THE REGION WILL MORE OR LESS BE IN BETWEEN
SYSTEMS WITH CONTINUED SOUTHERLY FLOW AND NOT MUCH IN THE WAY OF
FORCING. MAX TEMPERATURES WILL AGAIN BE A FEW DEGREES ABOVE NORMAL
AND COULD APPROACH 90 IN SOME LOCATIONS. THE DAYTIME HEATING OF THE
WARM AND RATHER MOIST AIR MASS IN PLACE BY THE AFTERNOON SHOULD LEAD
TO SOME DIURNALLY DRIVEN CONVECTION FOR MONDAY. AT THIS TIME...ONLY
ISOLATED POPS WERE USED.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 252 AM EDT SUN AUG 31 2014
SUMMER-LIKE WEATHER WILL PERSIST THIS WEEK WITH PLENTY OF WARM AND
HUMID CONDITIONS ON TAP. A STRONG RIDGE WILL CONTINUE TO RESIDE OVER
THE SOUTHEAST THROUGH THE WEEK. BEST CHANCE OF RAIN WILL COME ON
TUESDAY AS A SURFACE TROUGH DROPS INTO EASTERN KENTUCKY BEFORE
STALLING. SOME WEAK FORCING WILL YIELD SCATTERED TO NUMEROUS SHOWERS
AND STORMS THROUGH THE AFTERNOON AND EVENING HOURS. DECENT SHEAR
PROFILES...COMBINED WITH MODEST INSTABILITY COULD YIELD THE
POSSIBILITY OF A FEW STRONG TO SEVERE STORMS ON TUESDAY WITH THE
MAIN THREAT BEING DAMAGING WINDS. OTHERWISE...THE FRONT WILL STALL
OVER THE AREA TUESDAY NIGHT...AND VIRTUALLY WASH OUT. THE
THREAT FOR AFTERNOON/EVENING SHOWERS WILL CONTINUE THROUGH WEEKS END
GIVEN THE DAYTIME INSTABILITY EACH AFTERNOON/EVENING. TEMPERATURES
WILL REMAIN NEAR OR SLIGHT ABOVE NORMAL THROUGH THE WEEK WITH ALL
THE COOLER AIR BOTTLED UP WELL TO OUR NORTH.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 130 PM EDT SUN AUG 31 2014
MVFR CONDITIONS CAN BE EXPECTED AT THE TAF SITES THROUGH AROUND 13Z
ON MONDAY...AS RAIN AND FOG FROM SHOWER AND STORM ACTIVITY AFFECT THE
TAF AIRPORTS. THE SHOWERS AND STORMS ARE EXPECTED TO TAPER OFF
QUICKLY AFTER 0Z THIS EVENING...WITH ISOLATED ACTIVITY AT BEST ACROSS
THE AREA AFTER 8Z. EASTERN KENTUCKY MIGHT EVEN BE RAIN FREE DURING
THE MORNING HOURS ON MONDAY...BEFORE SHOWERS AND STORMS BEGIN FIRING
UP AGAIN MONDAY AFTERNOON DURING PEAK HEATING AND AS YET ANOTHER
ATMOSPHERIC WAVE MOVES ACROSS THE REGION.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 6 PM EDT THIS EVENING FOR KYZ044-050>052-
058>060-068-069-079-080-083>086-104-106-108-111-114-116.
&&
$$
UPDATE...AR
SHORT TERM...JP
LONG TERM...KAS
AVIATION...AR
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
649 PM EDT SUN AUG 31 2014
.SYNOPSIS...
A COLD FRONT WILL DROP SOUTHEAST THROUGH THE REGION O0VERNIGHT
AND WILL STALL OFF THE COAST ON MONDAY. A SECOND COLD FRONT WILL
APPROACH FROM THE WEST ON TUESDAY AND WILL CROSS THE REGION
TUESDAY NIGHT. HIGH PRESSURE WILL BUILD IN FROM THE WEST ON
WEDNESDAY AND WILL CREST OVER THE REGION THURSDAY BEFORE SHIFTING
OFFSHORE. HIGH PRESSURE WILL HOLD OFF THE NEW ENGLAND COAST ON
FRIDAY. A COLD FRONT WILL CROSS THE AREA ON SATURDAY.
&&
.NEAR TERM /THROUGH MONDAY/...
UPDATE...LIGHT SHOWERS CONTINUE TO MOVE ACROSS THE BULK OF THE
CWFA ATTM. THIS HAS STABILIZED THE VAST MAJORITY OF THE AREA. THE
LINGERING INSTABILITY AXIS...FROM EARLIER DAYTIME
HEATING...REMAINS ACROSS SERN NH. THIS IS WHERE ANY STRONGER
CONVECTION WILL BE WATCHED TO DEVELOP. CURRENTLY ONE STRONGER
SHOWER IS MOVING TOWARDS THIS AREA...BUT ATTM HEAVY RNFL APPEAR TO
BE THE GREATEST THREAT. HOWEVER...CAPE VALUES REMAIN BETWEEN
500-1000 J/KG PER SPC MESOANALYSIS. WILL MAINTAIN THE GUSTY WIND
AND HEAVY RNFL WORDING IN THE GRIDS...AND JUST ADJUST POP TO
BETTER REFLECT RADAR TRENDS AT THIS HOUR.
WILL ALSO WATCH FOR A SECOND ROUND OF CONVECTION ACROSS THE NRN
ZONES...AS S/WV TROF NEARS LATER THIS EVENING. FORCING JUST
DOWNSTREAM FROM THE S/WV HAS KICKED OFF PLENTY OF TSTMS ACROSS ERN
ONTARIO AND NOW QUEBEC.
PREVIOUS DISCUSSION...A SHORT WAVE TROUGH APPROACHING FROM THE
WEST WILL WEAKEN THIS EVENING AS IT MOVES EASTWARD TOWARD NORTHERN
NEW ENGLAND. THE ATTENDANT SFC COLD FRONT WILL APPROACH AS
WELL...AND ALSO WEAKEN. A SHIELD OF LIGHT RAIN CONTINUES TO
TRAVERSE ACROSS NORTHERN AND CENTRAL ZONES AS OF 19Z THIS SUNDAY
AFTERNOON. THIS WILL STABILIZE THE AIRMASS ACROSS THIS AREA.
HOWEVER...ALONG THE COASTAL PLAIN SWWD OVER TO SOUTHERNMOST NH
SHOULD REMAIN MOSTLY DRY FOR THE NEXT SEVERAL HOURS.
THEREFORE...THESE AREAS SHOULD RETAIN THE INSTABILITY /1000-1500
J/KG SBCAPE/ THROUGH EARLY EVENING. THE QUESTION IS DO
THUNDERSTORMS DEVELOP IN THIS AREA.
SEVERAL OF THE LATEST RUNS OF THE HRRR CONTINUE TO SHOW
THUNDERSTORMS WILL HEAVY RAINFALL MOVING ACROSS SOUTHERNMOST NH
AND SOUTHERNMOST ME BETWEEN 22Z AND 03Z. THIS SEEMS REASONABLE
GIVEN THE CURRENT MESOSCALE SETUP. AS A RESULT WILL CONTINUE WITH
HIGH POPS...ESPECIALLY IN THIS AREA. MODERATE DEEP LAYER SHEAR MAY
AID IN A FEW OF THESE STORMS BECOMING STRONG...WITH GUSTY WINDS
BEING THE MAIN THREAT. WITH PWATS INCREASING TO AROUND 2 INCHES BY
EARLY EVENING...TORRENTIAL DOWNPOURS WILL BE LIKELY IN ANY
THUNDERSTORM. THERE IS A LOW PROB FOR TRAINING STORMS ACROSS
SOUTHERN NH AND SOUTHERNMOST ME...SO LOCALIZED FLASH FLOODING WILL
BE POSSIBLE THIS EVENING. THE BULK OF THE ACTIVITY SHOULD MOVE
OFFSHORE AROUND MIDNIGHT LEADING TO A MAINLY DRY OVERNIGHT.
&&
.SHORT TERM /MONDAY NIGHT/...
ON MONDAY...THE SHORT WAVE TROUGH WILL DEPART IN THE MORNING.
STILL...WITH MODERATE AMOUNTS OF LOW LEVEL THETA-E IN TANDEM WITH
SLIGHTLY COOLER TEMPS ALOFT AND A WEAK SFC FRONT IN THE VCNTY...WE
COULD SEE A FEW SHOWERS DURING THE DAY...PERHAPS A THUNDERSTORM.
HOWEVER...ACTIVITY SHOULD BE FEW AND FAR BETWEEN...WITH HIGHEST
POPS ACROSS CENTRAL AND NORTHERN ZONES. HUMID CONDITIONS WILL
CONTINUE.
MUGGY AND QUIET MONDAY NIGHT.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
COLD FRONT APPROACHES FROM THE WEST ON TUESDAY AND WILL
SET THE STAGE FOR POSSIBLE SEVERE WEATHER. PRE-FRONTAL
TROUGH FORECAST TO PUSH IN FROM THE WEST DURING PRIME TIME
HEATING. MODERATE CAPES AND INCREASING SHEAR DURING THE
AFTERNOON AND EVENING HOURS WILL LIKELY RESULT IN MORE
ORGANIZED CONVECTION DURING THE LATE AFTERNOON AND EVENING WITH
DAMAGING WINDS THE MAIN THREAT. STRONGER CELLS MAY ALSO PRODUCE
SOME HAIL BUT FREEZING LEVELS WILL BE QUITE HIGH SO NOT LOOKING
FOR MUCH IN THE WAY OF SEVERE HAIL. WILL SEE A HOT AND MUGGY DAY
WITH HIGHS RANGING THROUGH THE 80S.
COLD FRONT WILL PUSH OFFSHORE TUESDAY NIGHT WITH CONVECTION ENDING
ACROSS THE REGION BY MIDNIGHT. HIGH PRESSURE BUILDING IN FROM THE
WEST WILL BRING CLEARING DOWNWIND OF THE MOUNTAINS. LOW TEMPS
OVERNIGHT WILL RANGE THROUGH THE 60S.
COOLER AND MUCH DRIER AIR PUSHES IN FOR WEDNESDAY AS HIGH PRESSURE
CONTINUES TO BUILD INTO THE NORTHEAST. SHOULD SEE A MOSTLY SUNNY
DAY WITH HIGHS FROM THE MID 70S TO LOWER 80S.
FAIR WEATHER WILL CONTINUE THURSDAY AND FRIDAY AS HIGH PRESSURE
CONTINUES TO BUILD SOUTH OF THE REGION FINALLY PUSHING OFFSHORE
ON FRIDAY. AFTER A STELLAR LATE SUMMER DAY ON THURSDAY...RETURN
FLOW WILL BEGIN TO PUMP WARMER AND MORE HUMID AIR BACK INTO THE
REGION ON FRIDAY. MAY SEE ENOUGH INSTABILITY CREEP INTO THE
CONNECTICUT VALLEY LATE FRIDAY TO KICK OFF AN ISOLATED SHOWER OR
THUNDERSTORM BUT THE MAJORITY OF THE FORECAST AREA WILL SEE A DRY
DAY.
RATHER STRONG LOOKING COLD FRONT FORECAST TO PUSH IN FROM THE WEST
ON SATURDAY WHICH COULD PRODUCE ANOTHER ROUND OF SEVERE
THUNDERSTORMS.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
SHORT TERM...LOCAL IFR IN SHOWERS AND THUNDERSTORMS THIS EVENING.
AFTER MIDNIGHT...FOG AND SOME LOW STRATUS MAY DEVELOP AND RESULT
IN LOW CONDITIONS AS WELL. MAINLY VFR EXPECTED ON MONDAY OUTSIDE
OF WDLY SCT SHOWERS.
LONG TERM...MAINLY VFR EXPECTED OUTSIDE OF ANY SHOWERS AND
THUNDERSTORMS TUE EVE/NIGHT. SOME VALLEY FOG AND COASTAL STRATUS
POSSIBLE DURING THE PERIOD LATE AT NIGHT.
&&
.MARINE...
SHORT TERM...SCA FOR THE OUTER WATERS FOR TONIGHT.
OTHERWISE...SUB-SCA CONDITIONS LIKELY THROUGH MONDAY NIGHT.
LONG TERM...SUB-SCA EXPECTED TUE THROUGH FRI.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT MONDAY FOR ANZ150-152.
&&
$$
NEAR TERM...LEGRO
AREA FORECAST DISCUSSION
NWS GRAY ME
323 PM EDT SUN AUG 31 2014
.SYNOPSIS...
A COLD FRONT WILL DROP SOUTHEAST THROUGH THE REGION O0VERNIGHT
AND WILL STALL OFF THE COAST ON MONDAY. A SECOND COLD FRONT WILL
APPROACH FROM THE WEST ON TUESDAY AND WILL CROSS THE REGION
TUESDAY NIGHT. HIGH PRESSURE WILL BUILD IN FROM THE WEST ON
WEDNESDAY AND WILL CREST OVER THE REGION THURSDAY BEFORE SHIFTING
OFFSHORE. HIGH PRESSURE WILL HOLD OFF THE NEW ENGLAND COAST ON
FRIDAY. A COLD FRONT WILL CROSS THE AREA ON SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
A SHORT WAVE TROUGH APPROACHING FROM THE WEST WILL WEAKEN THIS
EVENING AS IT MOVES EASTWARD TOWARD NORTHERN NEW ENGLAND. THE
ATTENDANT SFC COLD FRONT WILL APPROACH AS WELL...AND ALSO WEAKEN.
A SHIELD OF LIGHT RAIN CONTINUES TO TRAVERSE ACROSS NORTHERN AND
CENTRAL ZONES AS OF 19Z THIS SUNDAY AFTERNOON. THIS WILL STABILIZE
THE AIRMASS ACROSS THIS AREA. HOWEVER...ALONG THE COASTAL PLAIN
SWWD OVER TO SOUTHERNMOST NH SHOULD REMAIN MOSTLY DRY FOR THE NEXT
SEVERAL HOURS. THEREFORE...THESE AREAS SHOULD RETAIN THE
INSTABILITY /1000-1500 J/KG SBCAPE/ THROUGH EARLY EVENING. THE
QUESTION IS DO THUNDERSTORMS DEVELOP IN THIS AREA.
SEVERAL OF THE LATEST RUNS OF THE HRRR CONTINUE TO SHOW
THUNDERSTORMS WILL HEAVY RAINFALL MOVING ACROSS SOUTHERNMOST NH
AND SOUTHERNMOST ME BETWEEN 22Z AND 03Z. THIS SEEMS REASONABLE
GIVEN THE CURRENT MESOSCALE SETUP. AS A RESULT WILL CONTINUE WITH
HIGH POPS...ESPECIALLY IN THIS AREA. MODERATE DEEP LAYER SHEAR MAY
AID IN A FEW OF THESE STORMS BECOMING STRONG...WITH GUSTY WINDS
BEING THE MAIN THREAT. WITH PWATS INCREASING TO AROUND 2 INCHES BY
EARLY EVENING...TORRENTIAL DOWNPOURS WILL BE LIKELY IN ANY
THUNDERSTORM. THERE IS A LOW PROB FOR TRAINING STORMS ACROSS
SOUTHERN NH AND SOUTHERNMOST ME...SO LOCALIZED FLASH FLOODING WILL
BE POSSIBLE THIS EVENING. THE BULK OF THE ACTIVITY SHOULD MOVE
OFFSHORE AROUND MIDNIGHT LEADING TO A MAINLY DRY OVERNIGHT.
&&
.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
ON MONDAY...THE SHORT WAVE TROUGH WILL DEPART IN THE MORNING.
STILL...WITH MODERATE AMOUNTS OF LOW LEVEL THETA-E IN TANDEM WITH
SLIGHTLY COOLER TEMPS ALOFT AND A WEAK SFC FRONT IN THE VCNTY...WE
COULD SEE A FEW SHOWERS DURING THE DAY...PERHAPS A THUNDERSTORM.
HOWEVER...ACTIVITY SHOULD BE FEW AND FAR BETWEEN...WITH HIGHEST
POPS ACROSS CENTRAL AND NORTHERN ZONES. HUMID CONDITIONS WILL
CONTINUE.
MUGGY AND QUIET MONDAY NIGHT.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
COLD FRONT APPROACHES FROM THE WEST ON TUESDAY AND WILL
SET THE STAGE FOR POSSIBLE SEVERE WEATHER. PRE-FRONTAL
TROUGH FORECAST TO PUSH IN FROM THE WEST DURING PRIME TIME
HEATING. MODERATE CAPES AND INCREASING SHEAR DURING THE
AFTERNOON AND EVENING HOURS WILL LIKELY RESULT IN MORE
ORGANIZED CONVECTION DURING THE LATE AFTERNOON AND EVENING WITH
DAMAGING WINDS THE MAIN THREAT. STRONGER CELLS MAY ALSO PRODUCE
SOME HAIL BUT FREEZING LEVELS WILL BE QUITE HIGH SO NOT LOOKING
FOR MUCH IN THE WAY OF SEVERE HAIL. WILL SEE A HOT AND MUGGY DAY
WITH HIGHS RANGING THROUGH THE 80S.
COLD FRONT WILL PUSH OFFSHORE TUESDAY NIGHT WITH CONVECTION ENDING
ACROSS THE REGION BY MIDNIGHT. HIGH PRESSURE BUILDING IN FROM THE
WEST WILL BRING CLEARING DOWNWIND OF THE MOUNTAINS. LOW TEMPS
OVERNIGHT WILL RANGE THROUGH THE 60S.
COOLER AND MUCH DRIER AIR PUSHES IN FOR WEDNESDAY AS HIGH PRESSURE
CONTINUES TO BUILD INTO THE NORTHEAST. SHOULD SEE A MOSTLY SUNNY
DAY WITH HIGHS FROM THE MID 70S TO LOWER 80S.
FAIR WEATHER WILL CONTINUE THURSDAY AND FRIDAY AS HIGH PRESSURE
CONTINUES TO BUILD SOUTH OF THE REGION FINALLY PUSHING OFFSHORE
ON FRIDAY. AFTER A STELLAR LATE SUMMER DAY ON THURSDAY...RETURN
FLOW WILL BEGIN TO PUMP WARMER AND MORE HUMID AIR BACK INTO THE
REGION ON FRIDAY. MAY SEE ENOUGH INSTABILITY CREEP INTO THE
CONNECTICUT VALLEY LATE FRIDAY TO KICK OFF AN ISOLATED SHOWER OR
THUNDERSTORM BUT THE MAJORITY OF THE FORECAST AREA WILL SEE A DRY
DAY.
RATHER STRONG LOOKING COLD FRONT FORECAST TO PUSH IN FROM THE WEST
ON SATURDAY WHICH COULD PRODUCE ANOTHER ROUND OF SEVERE
THUNDERSTORMS.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
SHORT TERM...LOCAL IFR IN SHOWERS AND THUNDERSTORMS THIS EVENING.
AFTER MIDNIGHT...FOG AND SOME LOW STRATUS MAY DEVELOP AND RESULT
IN LOW CONDITIONS AS WELL. MAINLY VFR EXPECTED ON MONDAY OUTSIDE
OF WDLY SCT SHOWERS.
LONG TERM...MAINLY VFR EXPECTED OUTSIDE OF ANY SHOWERS AND
THUNDERSTORMS TUE EVE/NIGHT. SOME VALLEY FOG AND COASTAL STRATUS
POSSIBLE DURING THE PERIOD LATE AT NIGHT.
&&
.MARINE...
SHORT TERM...SCA FOR THE OUTER WATERS FOR TONIGHT.
OTHERWISE...SUB-SCA CONDITIONS LIKELY THROUGH MONDAY NIGHT.
LONG TERM...SUB-SCA EXPECTED TUE THROUGH FRI.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR ANZ150-152.
&&
$$
NEAR TERM...MLE
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
329 PM EDT SUN AUG 31 2014
.SYNOPSIS...
BERMUDA HIGH PRESSURE WILL PERSIST THROUGH TUESDAY WITH AN ACTIVE
PATTERN FOR THE EASTERN SEABOARD. A WEAK COLD FRONT WILL CROSS THE
AREA TUESDAY NIGHT...FOLLOWED BY HIGH PRESSURE.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AREA BETWEEN I-81 AND THE BAY HAS RECEIVED PLENTY OF INSOLATION
TODAY...WHICH SUPPORTS THE DVLPMNT OF LEE TROFFING EVIDENT IN LTST
SFC ANALY. OTRW...THE NEAREST SYNOP FEATURE IS A WK CDFNT IN THE
ST LAWR VLY SWWD TO DTW. A BKN LINE OF SHRA/TSRA HAS DVLPD ALONG
THE DIFFERENTIAL HEATING BNDRY...FM FDK-OKV-HIGHLAND CO VA. ADDTL
TSRA CAN BE FOUND JUST OVER THE SUSQ RIVER IN CECIL CO.
MESO ANALY SUGGESTS A RIBBON OF MUCAPE AOA 2000 J/KG AND EFFECTIVE
BULK SHEAR ALONG AND JUST E OF THE AREA WHERE STORMS FORMING.
THEREFORE...SEE NO REASON WHY DVLPMNT WONT CONTINUE. HRRR HAS BEEN
PERFORMING RATHER WELL THUS FAR TDA. IT SUGGESTS THAT PCPN WL CONT
TO FILL IN AS AREA HEADS TWD I-95 BY 20-22Z. FCST IS BASED ON THIS
SCENARIO.
THERES ENUF CAPE AND SHEAR FOR ORGANIZATION TO OCCUR. THUS FAR
THATS FAILED TO HPPN...LKLY DUE TO WK MID LVL LAPSE RATES. IF WE
CAN OVERCOME THE ISSUES IN THE MID LVLS...THEN THE MOST LKLY
THREAT WUD COME FROM WET MICROBURSTS. IN ADDITION...PWAT NEAR 2
INCHES WUD SUPPORT HVY RAINERS.
THE TAIL OF A PVA LOBE WL CROSS THE AREA BTWN 00-06Z. HV HELD ONTO
LKLY OR HIER POPS ALL AREAS XCPT FOR CHO-EZF-NHK DUE TO THIS ADDED
SUPPORT. ONCE WE GET TOO MUCH LATER THAN THAT...WE WL LOSE OUR
HEATING...AND XPCT A DOWNWARD TREND TO THE STORMS.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY/...
WL STILL HV LEE TROF AND AN UNSTBL AMS MON. HWVR...FORCING FOR
PCPN WL BE LACKING. STILL XPCT SCT STORM DVLPMNT DURING THE
MIDDAY...WHICH WL BE DROPPING INTO THE LEE TROF DURING THE AFTN.
THE RELATIVE LACK OF ACTIVITY AND CLEARING SKIES FROM WEST-TO-
EAST WILL ALLOW TEMPS TO CLIMB BACK INTO THE U80S AND SOME L90S
FOR THE AREA ON MON AFTN...W/ DEWPOINTS STANDING PAT IN THE
U60S/L70S - ANOTHER MUGGY DAY FOR THE AREA.
WEAK RIDGING CROSSES THE CENTRAL MID-ATLANTIC MONDAY NIGHT INTO
TUESDAY...MAKING FOR A REPRIEVE IN THUNDERSTORMS FOR 12-18 HRS. WITH
THE BERMUDA HIGH IN PLACE...EXPECT TUESDAY TO HAVE THE HIGHEST
TEMPERATURE DAY SINCE JULY. MAX TEMPS LOW TO MID 90S ACROSS LOWER
ELEVATIONS.
THE NEXT COLD FRONT APPROACHES LATE TUESDAY AND CROSSES THAT NIGHT.
WITH PLENTY OF ENERGY FROM THE HOT DAY...EXPECT AT LEAST ISOLATED
SEVERE WEATHER...PARTICULAR FOR WRN ZONES THAT ARE PROGGED TO GET
THE EVENING ACTIVITY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
HIGH PRESSURE OVER THE CWA WILL MOVE OFFSHORE ALLOWING A COLD FRONT
FROM THE WEST TO ENTER THE CWA FRIDAY. ALTHOUGH PVA IS WEAK...
STALLED BOUNDARY AND MOISTURE WILL SUPPLY ACTIVE WEATHER INTO THE
WEEKEND.
&&
.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
VFR CONDS ACRS THE TERMINALS TAFTN. SCTD-NMRS SHRA/TSRA HV DVLPD E
OF MRB BUT W OF THE REST OF THE AIRFIELDS. DUE TO XPCTD CVRG AND
TRACKABLE FEATURES...TAFS NOW HV EXPLICIT THUNDER MENTION. IN
ADDITION...HV TEMPO FOR MOST LKLY TIME FRAME...22Z-02Z. HV MVFR
VSBY AND G30 KT. IF FULL CNVCTV DVLPMNT REALIZED AND AN AIRFIELD
TAKES A DIRECT HIT...IFR FLGT CONDS AND HIER GUSTS PSBL.
SLY WINDS WILL PERSIST INTO MON...ALONG W/ A FEW HIT/MISS SHOWERS
AS WELL THRU MON EVE.
BRIEF HIGH PRESSURE/VFR TUESDAY ON A HOT DAY (MAX TEMPS IN THE MID
90S). SCATTERED STRONG THUNDERSTORMS TUESDAY NIGHT AS A WEAK COLD
FRONT CROSSES THE REGION. HIGH PRESSURE/VFR OUTSIDE OF POTENTIAL
MORNING FOG MID TO LATE WEEK.
&&
.MARINE...
SLY FLOW ACRS THE MARINE AREA SUN-MON. MDL SNDGS DEPICT G20 KT
PSBL TAFTN...WHICH BEING FULLY REALIZED ATTM. HV RAISED SCA INTO
THE EVNG ALL WATERS. SLY FLOW PTTN CONTS INTO MON...BUT WNDS SHUD
BE LIGHTER.
SUB SCA SWLY FLOW MONDAY NIGHT THROUGH TUESDAY. WEAK COLD FRONT
BRINGS WLY FLOW LATE TUESDAY NIGHT THROUGH WEDNESDAY. HIGH PRESSURE
OVERHEAD WEDNESDAY NIGHT AND THURSDAY.
&&
.TIDES/COASTAL FLOODING...
DEPARTURES ON THE UPR TIDAL POTOMAC RIVER AND MOST OF THE BAY
STILL HOVERING AROUND 1 FT. LWTV2/SLIM2 STILL ONLY 3/4 FT ABOVE
NORMAL. A GOOD SLY FLOW CONTS ON THE WATERS...SO DO NOT ANTICIPATE
DEPARTURES TO DECREASE MUCH TNGT. BASED ON THESE TRENDS...
ANNAPOLIS WL EXCEED MINOR CRITERIA...AND SVRL OTHER SITES WL REACH
CAUTION STAGE. HV ISSUED COASTAL FLOOD ADVY FOR AA COUNTY...AND
MONITOR THE REST.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...COASTAL FLOOD ADVISORY FROM 9 PM THIS EVENING TO MIDNIGHT EDT
TONIGHT FOR MDZ014.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR
ANZ530>533-536>542.
SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR ANZ534-
543.
&&
$$
SYNOPSIS...BAJ
NEAR TERM...HTS
SHORT TERM...HTS/GMS
LONG TERM...CEM
AVIATION...HTS/BAJ
MARINE...HTS/BAJ
TIDES/COASTAL FLOODING...HTS
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
645 PM EDT SUN AUG 31 2014
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 322 PM EDT SUN AUG 31 2014
A WEAK AREA OF HIGH PRESSURE WILL KEEP MUCH OF THE REGION DRY INTO
THE EVENING. A COLD FRONT WILL APPROACH FROM THE WEST ON LABOR DAY
TRIGGERING SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL RETURN
FOR TUESDAY DRYING THE REGION OUT.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 322 PM EDT SUN AUG 31 2014
THE MAIN CHALLENGE IN THE SHORT TERM DEALS WITH THE POTENTIAL FOR
SEVERE WEATHER ON MONDAY. OVERALL THE POTENTIAL STILL EXISTS.
ONE POTENTIAL LIMITING FACTOR WILL BE WHAT IMPACTS THE DECAYING
AREA OF THUNDERSTORMS WILL HAVE AS IT MOVES IN FROM THE WEST
MONDAY MORNING. THE HRRR RUC SHOWS THIS SYSTEM WEAKENING WELL
BEFORE IT ARRIVES IN MI...SO I AM THINKING THIS WILL HAVE A
MINIMAL IMPACT ON THE POTENTIAL INSTABILITY MONDAY. THE
COMBINATION OF HEATING AND MOISTURE ADVECTION SUPPORTS CAPE OVER
1500 J/KG ON MONDAY. DEEP LAYER SHEAR INCREASES TOWARD 18Z AS THE
MID LEVEL WAVE CURRENTLY IN WI ARRIVES IN NW LOWER. THE LIFT
ASSOCIATED WITH THIS FEATURE SHOULD TRIGGER STORMS. THE SHEAR WILL
HELP TO INCREASE THE POTENTIAL FOR ORGANIZED CONVECTION AND
RESULTING SEVERE WEATHER. DAMAGING WINDS AND LARGE HAIL A THREAT.
SRH VALUES AROUND 200 M2/S2 DO SUPPORT A RISK FOR TORNADOES.
&&
.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 322 PM EDT SUN AUG 31 2014
MEDIUM RANGE MODELS ARE IN DECENT AGREEMENT INTO NEXT WEEKEND...
HOWEVER THERE ARE TIMING DIFFERENCES WITH A STRONG COLD FRONT THAT
COMES THROUGH FRIDAY/FRIDAY NIGHT.
LARGE HIGH PRESSURE IS EXPECTED TO BE SITTING OVER THE EAST SEABOARD
BY MID WEEK. THIS WILL BRING WARMING SOUTHERLY FLOW TO THE GREAT
LAKES REGION. IT CONTINUES TO LOOK LIKE THURSDAY WILL BE THE
WARMEST DAY OF THE WEEK WITH 80S FOR HIGHS. THE RISK FOR SHOWERS
AND STORMS WILL INCREASE ON THURSDAY WITH A COLD FRONT MOVING INTO
THE WESTERN GREAT LAKES. WARM AND MOIST AIR WITH MOVE IN AHEAD OF
THIS FRONT. IF A LOW LEVEL JET COMES INTO PLAY WE COULD BE LOOKING
AT STRONG TO SEVERE STORMS TOWARD THE END OF THE DAY.
THERE CONTINUES TO BE TIMING DIFFERENCES WITH THE FRONT...BUT THE
GFS SLOWED THE FRONT DOWN...CLOSER TO THE WHAT THE ECMWF HAS SHOWN.
THEREFORE BELIEVE THE FRONT WILL BE COMING THROUGH ON FRIDAY WITH
ADDITIONAL CHANCES FOR SHOWERS AND STORMS. MUCH COOLER AIR FOLLOWS
THIS STRONG FRONT FOR FRIDAY NIGHT AND INTO NEXT WEEKEND. H8 TEMPS
DROP TO +7 TO +10C AS COMPARED TO AROUND +19C AHEAD OF THE COLD
FRONT. THE WEEKEND SHOULD FEATURE HIGHS IN THE UPPER 60S TO MID 70S
WITH MAINLY DRY WEATHER.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 645 PM EDT SUN AUG 31 2014
SCATTERED SHOWERS MAY AFFECT OUR SOUTHEAST TERMINALS (KLAN AND
PERHAPS KBTL/KJXN) DURING THE EARLY TO MID EVENING HOURS TONIGHT
BEFORE DISSIPATING. MAINLY VFR CONDITIONS ARE ANTICIPATED OVERNIGHT
BUT SOME PATCHY MVFR CONDITIONS MAY DEVELOP DURING THE EARLY MORNING
HOURS MONDAY DUE TO LOW CLOUDS AND/OR FOG. CONDITIONS SHOULD THEN
GRADUALLY DETERIORATE TO MAINLY MVFR MONDAY MORNING DUE TO LOW
CLOUDS AND PATCHY FOG.
BY LATE MONDAY MORNING/EARLY AFTERNOON SSW WINDS WILL INCREASE WITH
GUSTS AROUND 20 TO 25 KTS. SCATTERED THUNDERSTORMS WILL ALSO DEVELOP
FROM LATE MONDAY MORNING THROUGH MONDAY AFTERNOON AS INSTABILITY
INCREASES AHEAD OF AN APPROACHING COLD FRONT. SCATTERED SHOWERS AND
THUNDERSTORMS WILL LINGER MONDAY EVENING.
&&
.MARINE...
ISSUED AT 322 PM EDT SUN AUG 31 2014
BEACH HAZARDS AND SCA ISSUED FOR MONDAY
&&
.HYDROLOGY...
ISSUED AT 322 PM EDT SUN AUG 31 2014
HIGH PWAT VALUES SUPPORT LOCALLY HEAVY RAIN ON MONDAY.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...BEACH HAZARDS STATEMENT FROM MONDAY MORNING THROUGH MONDAY
EVENING FOR MIZ037-043-050-056-064-071.
LM...SMALL CRAFT ADVISORY FROM 10 AM TO 10 PM EDT MONDAY FOR
LMZ844>849.
&&
$$
SYNOPSIS...MJS
SHORT TERM...MJS
LONG TERM...JK
AVIATION...LAURENS
HYDROLOGY...MJS
MARINE...MJS
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
330 PM EDT SUN AUG 31 2014
LATEST UPDATE...
SYNOPSIS/SHORT TERM/LONG TERM/HYDRO/MARINE
.SYNOPSIS...
ISSUED AT 322 PM EDT SUN AUG 31 2014
A WEAK AREA OF HIGH PRESSURE WILL KEEP MUCH OF THE REGION DRY INTO
THE EVENING. A COLD FRONT WILL APPROACH FROM THE WEST ON LABOR DAY
TRIGGERING SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL RETURN
FOR TUESDAY DRYING THE REGION OUT.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 322 PM EDT SUN AUG 31 2014
THE MAIN CHALLENGE IN THE SHORT TERM DEALS WITH THE POTENTIAL FOR
SEVERE WEATHER ON MONDAY. OVERALL THE POTENTIAL STILL EXISTS.
ONE POTENTIAL LIMITING FACTOR WILL BE WHAT IMPACTS THE DECAYING
AREA OF THUNDERSTORMS WILL HAVE AS IT MOVES IN FROM THE WEST
MONDAY MORNING. THE HRRR RUC SHOWS THIS SYSTEM WEAKENING WELL
BEFORE IT ARRIVES IN MI...SO I AM THINKING THIS WILL HAVE A
MINIMAL IMPACT ON THE POTENTIAL INSTABILITY MONDAY. THE
COMBINATION OF HEATING AND MOISTURE ADVECTION SUPPORTS CAPE OVER
1500 J/KG ON MONDAY. DEEP LAYER SHEAR INCREASES TOWARD 18Z AS THE
MID LEVEL WAVE CURRENTLY IN WI ARRIVES IN NW LOWER. THE LIFT
ASSOCIATED WITH THIS FEATURE SHOULD TRIGGER STORMS. THE SHEAR WILL
HELP TO INCREASE THE POTENTIAL FOR ORGANIZED CONVECTION AND
RESULTING SEVERE WEATHER. DAMAGING WINDS AND LARGE HAIL A THREAT.
SRH VALUES AROUND 200 M2/S2 DO SUPPORT A RISK FOR TORNADOES.
.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 322 PM EDT SUN AUG 31 2014
MEDIUM RANGE MODELS ARE IN DECENT AGREEMENT INTO NEXT WEEKEND...
HOWEVER THERE ARE TIMING DIFFERENCES WITH A STRONG COLD FRONT THAT
COMES THROUGH FRIDAY/FRIDAY NIGHT.
LARGE HIGH PRESSURE IS EXPECTED TO BE SITTING OVER THE EAST SEABOARD
BY MID WEEK. THIS WILL BRING WARMING SOUTHERLY FLOW TO THE GREAT
LAKES REGION. IT CONTINUES TO LOOK LIKE THURSDAY WILL BE THE
WARMEST DAY OF THE WEEK WITH 80S FOR HIGHS. THE RISK FOR SHOWERS
AND STORMS WILL INCREASE ON THURSDAY WITH A COLD FRONT MOVING INTO
THE WESTERN GREAT LAKES. WARM AND MOIST AIR WITH MOVE IN AHEAD OF
THIS FRONT. IF A LOW LEVEL JET COMES INTO PLAY WE COULD BE LOOKING
AT STRONG TO SEVERE STORMS TOWARD THE END OF THE DAY.
THERE CONTINUES TO BE TIMING DIFFERENCES WITH THE FRONT...BUT THE
GFS SLOWED THE FRONT DOWN...CLOSER TO THE WHAT THE ECMWF HAS SHOWN.
THEREFORE BELIEVE THE FRONT WILL BE COMING THROUGH ON FRIDAY WITH
ADDITIONAL CHANCES FOR SHOWERS AND STORMS. MUCH COOLER AIR FOLLOWS
THIS STRONG FRONT FOR FRIDAY NIGHT AND INTO NEXT WEEKEND. H8 TEMPS
DROP TO +7 TO +10C AS COMPARED TO AROUND +19C AHEAD OF THE COLD
FRONT. THE WEEKEND SHOULD FEATURE HIGHS IN THE UPPER 60S TO MID 70S
WITH MAINLY DRY WEATHER.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 134 PM EDT SUN AUG 31 2014
CEILINGS WERE TRENDING TOWARD VFR EARLY THIS AFTERNOON...HOWEVER
SOME MVFR MAY HOLD ON UNTIL ABOUT 20Z. OTHERWISE THE VFR AND LIGHT
WINDS WILL BE MAINTAINED INTO AND THROUGH MUCH OF THE OVERNIGHT. I
HAVE INTRODUCED SOME MVFR CEILINGS RETURNING AROUND DAYBREAK
MONDAY DUE TO MOIST LOW LEVELS AND DIURNAL TRENDS.
THEN BY LATE MONDAY MORNING/EARLY AFTERNOON SSW WINDS WILL
INCREASE WITH GUSTS AROUND 20 KNOTS. ALSO IN THIS TIME FRAME
WIDELY SCATTERED THUNDERSTORMS MAY BEGIN TO DEVELOP AS INSTABILITY
INCREASES AHEAD OF AN APPROACHING COLD FRONT.
&&
.MARINE...
ISSUED AT 322 PM EDT SUN AUG 31 2014
BEACH HAZARDS AND SCA ISSUED FOR MONDAY
&&
.HYDROLOGY...
ISSUED AT 322 PM EDT SUN AUG 31 2014
HIGH PWAT VALUES SUPPORT LOCALLY HEAVY RAIN ON MONDAY.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...BEACH HAZARDS STATEMENT FROM MONDAY MORNING THROUGH MONDAY
EVENING FOR MIZ037-043-050-056-064-071.
LM...SMALL CRAFT ADVISORY FROM 10 AM TO 10 PM EDT MONDAY FOR
LMZ844>849.
&&
$$
SYNOPSIS...MJS
SHORT TERM...MJS
LONG TERM...JK
AVIATION...JK
HYDROLOGY...MJS
MARINE...MJS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
224 PM EDT SUN AUG 31 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 514 AM EDT SUN AUG 31 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MID LEVEL RIDGE FROM THE
UPPER MS VALLEY THROUGH WRN LAKE SUPERIOR BTWN A DEPARTING SHRTWV
TROUGH INTO NRN LOWER MI AND AN UPSTREAM SHRTWV OVER THE WRN
DAKOTAS. ISOLATED SHOWERS ASSOCIATED WITH THE COMMA HEAD OF THE MI
SHRTWV WERE EXITING THE ERN CWA. HOWEVER...EXTENSIVE LOW LEVEL
MOISTURE/LOW CLOUDS PERSISTED OVER MUCH OF UPPER MI...EXCEPT FROM
CMX/P59 TO IWD. AT THE SFC...A RIDGE EXTENDED FROM JAMES BAY AND NRN
ONTARIO INTO WRN UPPER MI AND NW WI.
TODAY...AS THE 850-700 MB MOISTURE DEPARTS THIS MORNING AND DAYTIME
HEATING/MIXING INCREASES...EXPECT THAT THE REMAINING CLOUDS OVER THE
CNTRL AND EAST WILL THIN OUT AND GIVE WAY TO SCT CU BY AFTERNOON.
WITH SUBSIDENCE LIMITING INVERSION HEIGHTS CLOSER TO 900 MB...MAX
TEMPS MAINLY IN THE MID 70S ARE IN STORE WITH SOME LOWER READINGS
NEAR THE GREAT LAKES WHERE E OR SSE WINDS PREVAIL.
TONIGHT...AS THE DAKOTAS SHORTWAVE AND ASSOCIATED SFC TROUGH
APPROACH THE REGION SRLY FLOW AND MOISTURE ADVECTION WILL INCREASE.
AS PWAT VALUES CLIMB INTO THE 1.5-2.0 INCH RANGE FROM NW WI TO NEAR
IWD AND LARGE SCALE LIFT INCREASES WITH UPPER LEVEL DIV 700-300 MB
QVECTOR CONV AHEAD OF THE MID LEVEL TROUGH...SHRA/TSRA THAT DEVELOP
OVER MN WILL SPREAD TOWARD AND INTO THE CWA...MAINLY AFT 06Z. WITH
THE INITIAL PUSH OF 850-700 MB THETA-E ADVECTION SOME ISOLD SHRA/TSRA
MAY ALSO SPREAD INTO N CNTRL UPPER MI DURING THE EVENING...BUT
CONFIDENCE INTO CNTRL UPPER MI IS LOW WITH ONLY SLIGHT CHANCE POPS
MENTIONED. THE BEST CHANCE FOR SVR STORMS IS EXPECTED TO REMAIN WEST
OF THE CWA...CLOSER TO THE GREATER INSTABILITY. HOWEVER...WITH
MUCAPE VALUES TO AT LEAST 1K J/KG AND FAVORABLE 0-1KM/0-6KM SHEAR
TO 30/40 KNOTS...SOME STRONG STORMS WILL BE POSSIBLE WITH GUSTY
WINDS AND SMALL HAIL. THE MAIN HAZARD WITH TSRA LATE TONIGHT WILL BE
LOCALLY HEAVY RAIN WITH SOME ISOLD 1-2 INCH AMOUNTS POSSIBLE.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 224 PM EDT SUN AUG 31 2014
ASIDE FROM SOME MINOR PRECIP AMOUNTS POSSIBLE EARLY IN THE NIGHT
OVER FAR ERN UPPER MI DUE TO THE MON COLD FRONT EXITING THE
AREA...MON NIGHT AND TUE LOOK DRY FOR THE MOST PART AS SFC RIDGING
MOVES IN. A COUPLE MODELS SHOW A FEW HUNDREDTHS OF AN INCH OF QPF
TUE AFTERNOON AS A SHORTWAVE MOVES THROUGH THE REGION...BUT FORECAST
SOUNDINGS ARE JUST TOO DRY AND THE SHORTWAVE LOOKS TO GO TOO FAR SE
OF THE AREA TO HAVE PRECIP IN THE FORECAST. WILL KEEP A DRY
FORECAST. HIGH TEMPS LOOK TO BE FROM THE UPPER 60S TO MID 70S AS
850MB TEMPS WILL BE 9-11C.
FOR WED...SFC RIDGING MOVES E...SO SLY LOW LEVEL FLOW WILL BE ON THE
INCREASE UNDER ZONAL UPPER FLOW. MODELS SHOW VERY SUBTLE SHORTWAVE
ENERGY MOVING THROUGH THE AREA WED. OF COURSE...THIS FAR OUT THE
CONFIDENCE OF PRECIP RESULTING FROM WEAK SHORTWAVES IS MINIMAL...SO
WILL HAVE SLIGHT CHANCE POPS AT BEST.
FOR WED NIGHT THROUGH FRI NIGHT...MODELS TEND TO GENERALLY AGREE
THAT A STRONGER SHORTWAVE WILL MOVE INTO THE NCENTRAL CONUS AND
EVENTUALLY ACROSS OR NEAR THE CWA LATE FRI INTO FRI NIGHT. WHILE THE
ECMWF HAS SHOWN BETTER RUN TO RUN CONTINUITY WITH THE SHORTWAVE AND
RESULTING SFC LOW...THE UPPER LEVEL ENERGY IS CURRENTLY OVER THE
SEWARD PENINSULA OF ALASKA AND WILL ONLY ENTER THE CONUS OVER WA TUE
NIGHT. SHORTWAVE ENERGY THAT HAS YET TO REALLY DETACH FROM THE
PARENT UPPER LEVEL LOW OVER ALASKA NORMALLY LEADS TO PRETTY LOW
CONFIDENCE IN TIMING/TRACK 4-5 DAYS OUT...WHICH IS THE CASE HERE. DO
HAVE TO PREFER THE ECMWF SINCE IT HAS BEEN MORE STEADY FROM RUN TO
RUN...BUT CONFIDENCE IS STILL LOW SINCE THE GFS IS AROUND 18 HOURS
SLOWER AND FARTHER S WITH THE PASSAGE OF THE RESULTING SFC LOW THAN
THE ECMWF. OVERALL CONFIDENCE IN RAIN SOMEWHERE IN THE THU-FRI TIME
SPAN IS GOOD ENOUGH FOR HIGH CHANCE POPS...BUT TIMING WILL NEED TO
BE REFINED OVER THE NEXT FEW FORECASTS. AT THIS TIME...THE BEST
CHANCES FOR STRONG TO SEVERE STORMS /USING THE PREFERRED TIMING AND
TRACK OF THE ECMWF/ IS WED NIGHT INTO THU MORNING ALONG THE WARM
FRONT WHERE ELEVATED STORMS WOULD BE POSSIBLE...AND AGAIN LATE THU
INTO THU NIGHT AS MLCAPES APPROACH 3000J/KG WITH 0-6KM SHEAR OF
40-50KTS AND 0-1KM SHEAR AROUND 30KTS ALONG AND AHEAD OF THE COLD
FRONT. WHILE ALL MODES OF SEVERE WEATHER WOULD BE POSSIBLE WITH THE
ECMWF SOLUTION LATE THU INTO THU NIGHT...IT IS ALSO THE WORST CASE
SCENARIO. THE FARTHER S GFS WOULD RESULT IN MORE CLOUDS ON FRI
BEFORE THE SFC LOW AND COLD FRONT MOVE THROUGH...SO INSTABILITY
WOULD NOT BE AS STRONG. WILL NEED TO MONITOR AS CONFIDENCE IN SEVERE
CHANCE ARE LIMITED AND MODEL GUIDANCE WILL LIKELY CHANGE. FARTHER N
ECMWF IS ALSO WARMEST WITH 850MB TEMPS RISING TO AROUND 20C THU
AFTERNOON...WHICH WOULD RESULT IN HIGH TEMPS WELL INTO THE 80S OR
EVEN LOW 90S DEPENDING ON CLOUD AND PRECIP COVERAGE. WILL GO WITH A
MORE CONSENSUS APPROACH TO TEMPS GIVEN UNCERTAINTY.
NEXT WEEKEND LOOKS DRY AS COOLER HIGH PRESSURE SETTLES IN BEHIND THE
PREVIOUS SYSTEM. 850MB TEMPS FALL TO 3-4C ON SAT AND WARM TO 6-8C ON
SUN...SO COOLER CONDITIONS WITH HIGHS IN THE 60S TO LOW 70S ARE
EXPECTED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1206 PM EDT SUN AUG 31 2014
EXPECT LINGERING SC IFR CIGS AT CMX AND SAW TO DISSIPATE WITH MIXING
EARLY THIS AFTERNOON. OTHERWISE...VFR CONDITIONS WILL CONTINUE UNTIL
LATE TONIGHT INTO MON MORNING AS NEXT SYSTEM AND RAIN ARRIVES BY
THEN FOR IWD AND CMX. SAW IS A DIFFERENT STORY AS THERE IS A
POTENTIAL OF AN UPSLOPE LOW CLOUD/FOG EVENT FROM LAKE MICHIGAN WITH
SOUTH WINDS AND PUT THAT SCENARIO OF LIFR/IFR CONDITIONS WITH FOG
AND LOW CLOUDS THERE TONIGHT. ON MON MORNING...RAIN WILL HAVE
STARTED AND IFR/LIFR CONDITIONS FOR ALL SITES WILL PREVAIL. LLJ SETS
UP TONIGHT OFF THE SFC AT ALL SITES AND PUT IN LLWS TO COVER IT.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 514 AM EDT SUN AUG 31 2014
WINDS WILL BE LESS THAN 20 KTS OR LESS THROUGH MOST OF THE PERIOD
EXCEPT FOR A PERIOD OF SE TO S GUSTS OF 20 TO 30 KNOTS TONIGHT AND
MONDAY MORNING. WINDS WILL THEN VEER WRLY TO 20 KNOTS MON AFTERNOON
AND MON NIGHT IN THE WAKE OF A LOW PRESSURE SYSTEM AND COLD FRONT.
WIDESPREAD FOG WILL CONTINUE THROUGH THIS MORNING AND THEN DEVELOP
AGAIN TONIGHT INTO MONDAY NIGHT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1207 PM EDT SUN AUG 31 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 514 AM EDT SUN AUG 31 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MID LEVEL RIDGE FROM THE
UPPER MS VALLEY THROUGH WRN LAKE SUPERIOR BTWN A DEPARTING SHRTWV
TROUGH INTO NRN LOWER MI AND AN UPSTREAM SHRTWV OVER THE WRN
DAKOTAS. ISOLATED SHOWERS ASSOCIATED WITH THE COMMA HEAD OF THE MI
SHRTWV WERE EXITING THE ERN CWA. HOWEVER...EXTENSIVE LOW LEVEL
MOISTURE/LOW CLOUDS PERSISTED OVER MUCH OF UPPER MI...EXCEPT FROM
CMX/P59 TO IWD. AT THE SFC...A RIDGE EXTENDED FROM JAMES BAY AND NRN
ONTARIO INTO WRN UPPER MI AND NW WI.
TODAY...AS THE 850-700 MB MOISTURE DEPARTS THIS MORNING AND DAYTIME
HEATING/MIXING INCREASES...EXPECT THAT THE REMAINING CLOUDS OVER THE
CNTRL AND EAST WILL THIN OUT AND GIVE WAY TO SCT CU BY AFTERNOON.
WITH SUBSIDENCE LIMITING INVERSION HEIGHTS CLOSER TO 900 MB...MAX
TEMPS MAINLY IN THE MID 70S ARE IN STORE WITH SOME LOWER READINGS
NEAR THE GREAT LAKES WHERE E OR SSE WINDS PREVAIL.
TONIGHT...AS THE DAKOTAS SHORTWAVE AND ASSOCIATED SFC TROUGH
APPROACH THE REGION SRLY FLOW AND MOISTURE ADVECTION WILL INCREASE.
AS PWAT VALUES CLIMB INTO THE 1.5-2.0 INCH RANGE FROM NW WI TO NEAR
IWD AND LARGE SCALE LIFT INCREASES WITH UPPER LEVEL DIV 700-300 MB
QVECTOR CONV AHEAD OF THE MID LEVEL TROUGH...SHRA/TSRA THAT DEVELOP
OVER MN WILL SPREAD TOWARD AND INTO THE CWA...MAINLY AFT 06Z. WITH
THE INITIAL PUSH OF 850-700 MB THETA-E ADVECTION SOME ISOLD SHRA/TSRA
MAY ALSO SPREAD INTO N CNTRL UPPER MI DURING THE EVENING...BUT
CONFIDENCE INTO CNTRL UPPER MI IS LOW WITH ONLY SLIGHT CHANCE POPS
MENTIONED. THE BEST CHANCE FOR SVR STORMS IS EXPECTED TO REMAIN WEST
OF THE CWA...CLOSER TO THE GREATER INSTABILITY. HOWEVER...WITH
MUCAPE VALUES TO AT LEAST 1K J/KG AND FAVORABLE 0-1KM/0-6KM SHEAR
TO 30/40 KNOTS...SOME STRONG STORMS WILL BE POSSIBLE WITH GUSTY
WINDS AND SMALL HAIL. THE MAIN HAZARD WITH TSRA LATE TONIGHT WILL BE
LOCALLY HEAVY RAIN WITH SOME ISOLD 1-2 INCH AMOUNTS POSSIBLE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 433 AM EDT SUN AUG 31 2014
UPPER LEVELS FEATURE TROUGHING OVER THE CENTRAL CONUS TO BEGIN THE
PERIOD BUT THAT GIVES WAY TO SHALLOW RIDGING BY MID WEEK. SHORTWAVE
TROUGH MOVES FROM ROCKIES TO CENTRAL CANADA BY LATE THIS WEEK...WITH
WARM SW FLOW ALOFT STREAMING ACROSS THE GREAT LAKES. COLD FRONT MOVES
THROUGH AROUND FRIDAY WITH SFC RIDGE AND DRY/COOLER AIR SETTLING
OVER UPPER GREAT LAKES BY NEXT WEEKEND. CHANCES FOR SHRA/TSRA ON
LABOR DAY AS STRONG SHORTWAVE AND COLD FRONT CROSS UPPER GREAT
LAKES. THERE WILL BE ADDITIONAL CHANCES FOR SHRA AND TSRA AHEAD AND
ALONG THE LATE WEEK COLD FRONT AS WELL. EXPECT TEMPS FOR THE MOST
PART TO BE ABOVE NORMAL THROUGH THE WEEK. TEMPS PROBABLY WILL NOT
FALL BLO NORMAL UNTIL NEXT WEEKEND IN WAKE OF THE COLD FRONT PASSAGE
ON FRIDAY.
THUNDER CHANCES AND STRENGTH ON LABOR DAY AND AGAIN WEDNESDAY NIGHT
THROUGH FRIDAY LOOKS TO BE THE HIGHEST IMPACT WEATHER THIS WEEK.
LABOR DAY...INITIAL SHORTWAVE CURRENTLY DRIVING SHRA/TSRA OVER THE
DAKOTAS LIFTS OVER ONTARIO TO START THE DAY WHILE ANOTHER SHORTWAVE
CURRENTLY OVER OREGON/IDAHO TRACKS TOWARD WESTERN GREAT LAKES. MAIN
SFC LOW WILL BE NORTH OF LK SUPERIOR CLOSER TO LEADING SHORTWAVE. SFC
TROUGH WILL EXTEND SOUTH ACROSS UPPER GREAT LAKES REGION AND ON INTO
THE SOUTHERN PLAINS. H85-H5 Q-VECTOR CONVERGENCE MOSTLY IMPACTS CWA
IN THE MORNING. MOISTURE TRANSPORT AT H85-H7 IS MAXIMIZED AHEAD OF
THE FRONT IN THE MORNING AS WELL. THERE WILL BE SOME RISK FOR
STRONGER STORMS AS DURING THIS PERIOD OF FORCING/LIFT THERE IS A H85
JET UP TO 50 KTS FM THE SOUTHWEST/0-6KM SHEAR OVER 40 KTS AND 1-6KM
MUCAPES UP TO 500 J/KG. FREEZING LEVEL IS BTWN 12-13KFT WITH STORM
CORES HAVING TO REACH ABOVE 35 KFT FOR POTENTIAL OF ONE-INCH HAIL.
INSTABILITY WILL BE LIMITING FACTOR...BUT THERE MAY BE AT LEAST
ISOLATED STRONGER STORMS. BY AFTN...MLCAPES SPIKE UP WELL OVER 1000
J/KG ESPECIALLY CNTRL CWA...BUT SFC FRONT IS ON ITS WAY ACROSS CWA BY
THAT TIME AND LARGER SCALE SUBSIDENCE SHOULD BE DEVELOPING IN WAKE OF
SHORTWAVES MOVING THROUGH LATE TONIGHT INTO MONDAY MORNING. IF SFC
FRONT SLOWS UP...EVEN JUST SLIGHTLY...ISOLD STORMS MAY TRY TO DEVELOP
WITH THE INCREASING DAYTIME HEATING/INSTABILITY. RISK OF SEVERE STILL
THERE AS WELL WITH 0-6KM SHEAR 35-40 KTS. MAX TEMPS ON LABOR DAY
HIGHLY DEPEND ON EXTENT OF CLOUD COVER...BUT SEEMS THAT MANY AREAS
WILL SEE READINGS WELL INTO THE 70S. SOUTH WINDS MAY BE GUSTY OVER
EASTERN THIRD OF CWA...ESPECIALLY NEAR LK MICHIGAN SHORE.
FRONT CLEARS EASTERN CWA BY MONDAY EVENING WITH HIGH PRESSURE
SETTLING ACROSS FOR LATER MONDAY NIGHT INTO TUESDAY. ONSHORE WNW
WINDS WILL KEEP LK SUPERIOR SHORE COOLER ON TUESDAY IN THE MID-UPR
60S...BUT TEMPS SHOULD MAINLY BE IN THE LOWER 70S ELSEWHERE.
AS FLOW ALOFT BECOMES MORE ZONAL BY WEDNESDAY MAY START TO SEE
WEAKER SHORTWAVES WORK ACROSS UPR LAKES. GFS/GEM-NH AGGRESSIVE
WITH QPF ON WEDNESDAY BUT GFS SOUNDINGS INDICATE DEEPER MOISTURE IS
LACKING WITH ONLY WEAKER SHORTWAVES SHOWN. PREFER SLOWER ECMWF
SOLUTION SHOWING BETTER CHANCES OF SHRA/TSRA ARRIVING BY WEDNESDAY
NIGHT AS STRONGER SHORTWAVE ARRIVES. LAST FEW RUNS OF ECMWF ARE
SHOWING GREATER SIGNAL OF THIS OCCURRING. STRONG LOW-LEVEL MOISTURE
TRANSPORT AIMED INTO THE UPR LAKES ALONG WITH LARGE AREA OF ML
MUCAPES OVER 1000-1500 J/KG UPSTREAM WITH LIFT ENHANCED BY RIGHT
ENTRANCE REGION OF JET STREAK OVER ONTARIO/QUEBEC COULD RESULT IN AT
LEAST ISOLD STRONG ELEVATED STORMS WEDNESDAY NIGHT INTO THURSDAY
MORNING WITH ANOTHER ROUND OF STRONGER SFC BASED STORMS ALONG FRONTAL
BOUNDARY POSSIBLE LATER THURSDAY. LIMITING FACTOR FOR ADDITIONAL
STORMS LATER IN THE DAY WOULD BE NOT AS MUCH MOISTURE ALONG THE SFC
FRONT IN WAKE OF THE SHORTWAVE THAT MOVES THROUGH THURSDAY MORNING.
TEMPS AHEAD OF THE FRONT ON THURSDAY COULD GET QUITE WARM AS H85
TEMPS SURGE TOWARD +20C. WITH FULL SUNSHINE THIS WOULD SUPPORT HIGHS
INTO THE UPPER 80S IF NOT LOWER 90S. CURRENT FORECAST IS MORE TOWARD
CONSENSUS WITH UNCERTAINTY ON CLOUDS AND PRECIP CHANCES. WILL BE
SOMETHING THAT MAY NEED ADJUSTING IN LATER FORECASTS THOUGH.
THE FRONT...ALONG WITH SOME POTENTIAL FOR ADDITIONAL SHRA/TSRA...
SLIDES EAST AND SOUTH OF MOST CWA BY FRIDAY. HIGH PRESSURE MOVES
ACROSS FOR AT LEAST THE START OF NEXT WEEKEND WITH A MODEST COOLING
TREND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1206 PM EDT SUN AUG 31 2014
EXPECT LINGERING SC IFR CIGS AT CMX AND SAW TO DISSIPATE WITH MIXING
EARLY THIS AFTERNOON. OTHERWISE...VFR CONDITIONS WILL CONTINUE UNTIL
LATE TONIGHT INTO MON MORNING AS NEXT SYSTEM AND RAIN ARRIVES BY
THEN FOR IWD AND CMX. SAW IS A DIFFERENT STORY AS THERE IS A
POTENTIAL OF AN UPSLOPE LOW CLOUD/FOG EVENT FROM LAKE MICHIGAN WITH
SOUTH WINDS AND PUT THAT SCENARIO OF LIFR/IFR CONDITIONS WITH FOG
AND LOW CLOUDS THERE TONIGHT. ON MON MORNING...RAIN WILL HAVE
STARTED AND IFR/LIFR CONDITIONS FOR ALL SITES WILL PREVAIL. LLJ SETS
UP TONIGHT OFF THE SFC AT ALL SITES AND PUT IN LLWS TO COVER IT.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 514 AM EDT SUN AUG 31 2014
WINDS WILL BE LESS THAN 20 KTS OR LESS THROUGH MOST OF THE PERIOD
EXCEPT FOR A PERIOD OF SE TO S GUSTS OF 20 TO 30 KNOTS TONIGHT AND
MONDAY MORNING. WINDS WILL THEN VEER WRLY TO 20 KNOTS MON AFTERNOON
AND MON NIGHT IN THE WAKE OF A LOW PRESSURE SYSTEM AND COLD FRONT.
WIDESPREAD FOG WILL CONTINUE THROUGH THIS MORNING AND THEN DEVELOP
AGAIN TONIGHT INTO MONDAY NIGHT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1207 PM CDT SUN AUG 31 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 245 AM CDT SUN AUG 31 2014
ALTHOUGH SUNDAY AND ITS POTENTIAL SEVERE WEATHER EVENT ARE
HERE...THE CAMS STILL LEAVE PLENTY OF QUESTIONS AS TO HOW THINGS
WILL EVOLVE LATER TODAY.
FOR THIS MORNING...INITIAL SURGE OF THE LLJ IS MOVING ACROSS THE
DAKOTAS OUT AHEAD OF SHORTWAVE THAT CAN BE SEEN ON WATER VAPOR
MOVING INTO CENTRAL SODAK. ALTHOUGH BEST FORCING AND MOST WIDESPREAD
THUNDERSTORM ACTIVITY CAN BE FOUND AT THE NOSE OF THE LLJ ACROSS
NODAK AND ON ITS WAY TO NW MN...ENOUGH THETA-E ADVECTION AND
ISENTROPIC LIFT IS PRESENT ON THE ERN FLANK OF THE LLJ TO GET SCT
CONVECTION DOWN INTO NE NEB. THE HRRR/HOPWRF/MPXWRF/NMM/ARW ALL SHOW
THIS BAND OF ISO/SCT SHOWERS WORKING ACROSS MN THROUGH THE
MORNING...SO WORKED SOME 20/30 POPS ACROSS MN THIS MORNING TO
ACCOUNT FOR THAT. EXPECT THIS ACTIVITY TO START WEAKENING AS IT
MOVES EAST ACROSS MN AND LIKELY WILL NOT MAKE IT INTO WI AS IT
ENCOUNTERS A PROGRESSIVELY DRIER AIRMASS /SEE 00Z SOUNDING FROM MPX
LAST NIGHT/.
IN THE WAKE OF THIS MORNING ACTIVITY...H85 TEMPS WILL BE INCREASING
TO AROUND 20C. LOOKING AT BUFKIT SOUNDINGS FROM ACROSS THE
AREA...THIS WILL PUT A DECENT CAP IN PLACE THAT LOOKS TO KEEP A LID
ON SURFACE BASED CONVECTION UNTIL ABOUT 00Z. WHERE WE ARE SEEING
SOME VARIABILITY THOUGH WITH THE CAMS IS WITH THE POTENTIAL FOR SOME
ELEVATED CONVECTION TO DEVELOP THIS AFTERNOON OUT AHEAD OF WHAT YOU
COULD CONSIDER THE MAIN SHOW FROM THE SEVERE WEATHER PERSPECTIVE.
THIS ELEVATED CONVECTION LOOKS TO BE TIED TO THE STRONG WAVE ON
WATER VAPOR CURRENTLY MOVING INTO WRN KS. THIS FEATURE HAS A FEW
STORMS ASSOCIATED WITH IT IN KANSAS THIS MORNING AND BY THE
AFTERNOON...THIS WAVE WILL BE NEAR THE MN/IA BORDER. THE CAMS THAT
ARE MOST BULLISH WITH THIS ACTIVITY ARE THE MPXWRF AND ARW...AND
ALTHOUGH IT ENDS AT 21Z...YOU GET A SENSE FROM THE HRRR REFLECTIVITY
FORECAST...IT MAY BE GOING THE SAME WAY IN THE NEXT COUPLE OF RUNS.
THE IMPACT OF THIS ACTIVITY ON THE FORECAST WAS TO SPREAD HIGHER
POPS A BIT FARTHER EAST LATE THIS AFTERNOON THAN THE POSITION OF THE
SFC FEATURES WOULD OTHERWISE SUGGEST.
AS FOR THE POTENTIAL SFC BASED CONVECTION...THE MAIN TREND SEEN WITH
THE CAMS AND 00Z DETERMINISTIC MODELS WAS DELAY ITS START
SOME...WHICH MAKE SENSE GIVEN THE CAPPING SEEN IN THE FORECAST
SOUNDINGS. CURRENT EXPECTATIONS ARE THAT SFC BASED CONVECTION WILL
DEVELOP AROUND 21Z NEAR OMAHA...WHERE INSTABILITY WILL BE
MAXIMIZED...WITH INITIATION ALONG THE FRONT UP IN MN COMING A BIT
CLOSER TO 00Z. GREATEST SEVERE THREAT REALLY LOOKS TO BE DOWN ACROSS
IOWA...WHERE THE COMBINATION OF AN IMPINGING WRLY MID LEVEL JET WITH
A 40-50 KT SWRLY LLJ LOOKS TO MAXIMIZE SHEAR. CAN NOT ARGUE WITH THE
DAY1 SEVERE PROBABILITIES...WHICH HAS THE GREATER SEVERE POTENTIAL
EXISTING FROM I-90 SOUTH. LOOKING AT THE 0-3/0-6 KM SHEAR OF 30-60
KTS WITH VECTORS ORIENTED MOSTLY PERPENDICULAR TO THE FRONT ACROSS
IOWA INDICATES THE POTENTIAL FOR GETTING A STRONG MCS WITH STRONG
WINDS ACROSS IOWA TONIGHT...WHICH IS WHAT THE NMM/ARW CERTAINLY SHOW
EVOLVING. STILL A GOOD DEGREE OF VARIABILITY WITH HOW THIS ACTIVITY
WILL EVOLVE ACROSS THE MPX CWA...WITH SOME SUGGESTION THAT WE MAY
SEE THE GREATEST THUNDERSTORM ACTIVITY SPLIT THE MPX CWA TO THE
NORTH AND SOUTH. CERTAINLY THE HRRR MSLP FORECAST SHOWS SOME MERIT
TO THIS POSSIBILITY...WITH TWO SFC LOWS NOTED BY 21Z. ONE UP IN NRN
MN AND THE OTHER IN WRN KS.
FOR TONIGHT...WE ARE ALSO SEEING THE NMM AND THE ARW TO A LESSER
EXTENT HANGING UP ACTIVITY BACK ACROSS THE CENTER OF THE MPX CWA AS
THEY BOTH DEVELOP A DEFORMATION BAND IN THE WAKE IN THE MAIN COLD
FRONT ACTIVITY. THIS LOOKS TO BE TIED TO THE MAIN SHORT WAVE
POSSIBLY MIXED WITH A BIT OF AN MCV MOVING ACROSS THE UPPER MS
VALLEY LATE TONIGHT. AS A RESULT...HELD ON TO CHANCE POPS A BIT
LONGER BACK ACROSS MOST OF THE MN PORTION OF THE MPX CWA IN THE WAKE
OF THE FRONT. THIS ACTIVITY WOULD NOT HAVE MUCH OF A SEVERE
THREAT...THOUGH IT WOULD SET UP MORE IN A WAY TO ALLOW FOR SOME
TRAINING OF STORMS ALONG A SW TO NE AXIS...SO IT COULD POSE MORE OF
A HYDRO THREAT IF IT MATERIALIZES.
TO SUMMARIZE...WE EXPECT A BAND OF NON-SEVERE SHOWERS/STORMS TO MOVE
ACROSS MN THIS MORNING. STILL A GOOD DEGREE OF UNCERTAINTY WITH
RESPECT THE AFTERNOON ACTIVITY...WITH THE POTENTIAL FOR A PREFRONTAL
TROUGH TO GET ELEVATED CONVECTION GOING BY EARLY AFTERNOON IN THE
EAST...WITH THE GREATEST SEVERE RISK EXISTING FROM ABOUT 6 PM TO
MIDNIGHT FROM SOUTH CENTRAL MN INTO IOWA AHEAD OF THE MAIN SFC COLD
FRONT. EVENTUALLY...A LINE OR TWO OF STORMS LOOKS TO FORM...WITH THE
MAIN SEVERE THREAT BEING DAMAGING STRAIGHT LINE WINDS.
HOWEVER...WHERE ACTIVITY INITIALLY DEVELOPS...IT WILL LIKELY BE
SUPER CELLULAR IN NATURE...WITH LARGE HAIL AND A FEW TORNADOES BEING
POSSIBLE AS WELL...BUT THIS THREAT LOOKS GREATEST FROM ERN NEB INTO
WRN IOWA.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 245 AM CDT SUN AUG 31 2014
THE LONGER TERM WILL INCLUDE SOME ADDITIONAL CHANCES FOR
SHRA/TSRA AS WE SEE THE LARGE SCALE PATTERN ONCE AGAIN BECOME MORE
ZONAL BY THE MIDDLE OF THE WEEK... BEFORE ANOTHER UPPER TROUGH
MOVES INTO THE CENTER OF THE COUNTRY TOWARD THE WEEKEND. THE
MEDIUM RANGE GUIDANCE IS IN FAIRLY GOOD AGREEMENT THROUGH
MIDWEEK... BUT DIVERGES A FAIR AMOUNT BY THE WEEKEND... WHICH
LEADS TO MORE UNCERTAINTY AND NECESSITATES THE INCLUSION OF CHANCE
POPS FOR SEVERAL DAYS.
SOME PCPN WILL LIKELY STILL BE ONGOING ACROSS THE EASTERN PORTION
OF THE AREA ON MONDAY AS THE FRONTAL BOUNDARY SLOWLY PUSHES EAST
INTO THE GREAT LAKES. COULD SEE A FEW SHRA/TSRA SNEAK BACK INTO
THE WESTERN AND CENTRAL PORTION OF THE AREA MONDAY NIGHT INTO
EARLY TUESDAY AS THE UPPER TROUGH/COLD POOL SWING THROUGH THE
REGION. THIS ACTIVITY WILL SHIFT NORTHEAST BY TUESDAY... WITH
RETURN FLOW BEGINNING TO SETUP BY TUESDAY NIGHT. CHANCES FOR
SHRA/TSRA LOOK TO RETURN FROM WEST TO EAST WEDNESDAY INTO THURSDAY
AS A SURFACE LOW SLOWLY TAKES SHAPE OVER THE PLAINS AHEAD OF THE
NEXT UPPER TROUGH... WITH A LONG PERIOD OF MAINLY WEAK ISENTROPIC
LIFT PROGGED ACROSS OUR AREA. THE SPEED WITH WHICH THE SURFACE LOW
MOVES THROUGH OUR AREA VARIES QUITE A BIT AMONGST THE GUIDANCE...
AND AT THIS POINT THERE IS TOO MUCH SPREAD IN THE ENSEMBLE
SOLUTIONS TO HAVE MUCH CONFIDENCE IN ANYTHING SPECIFIC. UNTIL THE
SURFACE LOW AND ASSOCIATED FRONTAL BOUNDARY MOVE THROUGH... WE/LL
CONTINUE TO HAVE A NEED FOR AT LEAST CHANCE POPS. THERE IS ALSO
UNCERTAINTY IN HOW FAR SOUTH THE BOUNDARY WILL BE DISPLACED ONCE
THE SURFACE LOW AND UPPER TROUGH MOVE EAST... WITH THE GUIDANCE
SHOWING VARYING AMPLITUDES OF THE UPPER TROUGH WHICH LEADS TO
DIFFERENCES IN HOW FAR SOUTH THE BOUNDARY IS DISPLACED AS THE
SURFACE HIGH BUILDS INTO THE AREA LATE FRIDAY INTO SATURDAY. AT
THIS POINT... KEPT SOME POPS OVER THE SOUTHERN PART OF THE AREA
INTO SATURDAY TO ACCOUNT FOR THE POSSIBILITY OF THE BOUNDARY
HANGING UP OVER NORTHERN IOWA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1155 AM CDT SUN AUG 31 2014
LOW CONFIDENCE IN TSRA/SHRA DEVELOPMENT AFT 21Z WITH SHORT TERM
MODELS HAVING PROBLEMS WITH THE CONVECTION ALREADY DEVELOPING NEAR
KRWF/KFRM AS OF 17Z. WILL USE REGIONAL RADAR AND MOVEMENT TRENDS
FOR THE FIRST 3 HRS AS THIS LINE BECOMES MORE ORGANIZED AND MOVES
OFF TO THE NE. KRWF/KSTC WILL BE MOST IMPACTED IN THE SHORT TERM.
ELSEWHERE...TSRA/SHRA SHOULD HOLD OFF UNTIL AFT 21Z...WITH A
BETTER CHC AFT 00Z AS THE MAIN UPPER WAVE AND SFC FRONT MOVES
CLOSER TO THE AREA. WINDS WILL BE GUSTY THIS AFTN FROM THE
S/SW...WITH A MORE SW/WSW BY THE LATE AFTN IN WC/SW MN AND
DECREASE TO LESS THAN 10 KTS. EC MN/WC WI WILL LIKELY SEE THE
GUSTY WINDS UNTIL 00Z FROM THE S/SSW.
AM CONCERN WITH AREAS FROM SC/EC MN...EASTWARD ACROSS WC WI AFT 2Z
AS A LARGE AREA OF CONVECTION IS EXPECTED TO DEVELOP. WILL ADJUST
AS NECESSARY BUT IFR/MVFR CIGS/VSBYS FOR KRNH/KEAU LOOK MORE
LIKELY OVERNIGHT.
KMSP...
BASED ON THE LATEST REGIONAL RADAR MOST OF THE ACTIVITY SHOULD
HOLD OFF TO THE WEST UNTIL AFT 20-21Z...WITH A PERIOD OF VCTS FROM
20-23Z...BUT LOW CONFIDENCE ON AREAL EXTENT. A BETTER CHC OF
WIDESPREAD ACTIVITY IS EXPECTED AFT 2Z...WITH A PERIOD OF HEAVY
SHRA/TSRA AND LOW VSBYS. AFT 6Z...CHC/S OF SHRA/TSRA
DIMINISH...BUT MVFR CIGS AND/OR VSBYS MAY DEVELOP BEHIND THE SFC
FRONT...ESPECIALLY DURING THE TYPICAL 09-14Z TIME FRAME. IF MVFR
CIGS DEVELOP...DO NOT EXPECT VFR CONDS UNTIL AFT 16-18Z ON MONDAY.
/OUTLOOK FOR KMSP/
MON...VFR BY AFTERNOON WINDS WNW 5-10 KTS.
TUE...VFR. WINDS WSW 5-10 KTS.
WED...VFR. CHC MVFR/TSRA LATE. WINDS S 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...
AVIATION...JLT
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
357 PM CDT Sun Aug 31 2014
.SHORT TERM...(This Evening through Wednesday Afternoon)
Issued at 357 PM CDT SUN AUG 31 2014
Afternoon water vapor imagery showing long advertised Pacific trough
digging into the central Plains this afternoon...with strong
shortwave energy now seen entering western Nebraska. Strengthening
wind fields along the southern edge of this feature have advected
Mexican Plateau air /i.e. elevated mixed layer/ east across the
central/southern Plains as seen on the latest 7.4 micron water vapor
GOES sounder channel. Latest RUC analysis shows 7-500 mb lapse rates
approaching 9C/km across western Kansas and Nebraska...and fcst
models suggest this mid-level airmass will continue tracking east
into our region overnight. Along the surface...latest analysis shows
a developing leeside low across southeastern Colorado...with a
northward extending frontal boundary draped across the Plains which
then joins the main area of low pressure now found along the
Minnesota/Manitoba border. With time this evening...aforementioned
boundary will progress eastward as upstream troughing continues to
settle into the central and southern Plains. Airmass ahead of both
the cold front and upper wave continues to destabilize with latest
SPC meso graphics yielding as much as 3500 joules of MLCAPE between
KC and Topeka. Most importantly however...deep layered shear will
continue increasing as well as mid- level wind max moves into the
area overnight. All said...ingredients appear to be coming together
for a fairly active evening and overnight period.
Latest radar trends now showing developing cells across north-central
Kansas along the previously mentioned frontal boundary. Storms
should continue to fire this afternoon before gradually spreading east
through the early evening and overnight. As has been advertised in
recent days quite well by numerical models...isolated convection to
our west and north will likely congeal into a forward propagating MCS
this evening just before it enters northwestern Missouri. As this
occurs...deep layered shear will continue to strengthen as a low-
level jet increases to nearly 50 kts directly overhead. This poses
two potential issues for our region:
1) Maintenance of ongoing severe weather as cold pool continues to
track southeast with time into northwest Missouri/northeast Kansas
2) Increasing likelihood for developing heavy rain/possible flooding as
low-level jet ascends any convectively generated cold pools
The above said...main concerns severe-wise for our area will remain
strong damaging winds as cold pool for developing MCS tracks south
and east with time. Current thinking is damaging wind potential will
gradually decrease as storms approach the greater KC area...however
cannot rule out strong gusts in and around the metro during the late
evening hrs. Additionally...a low-end tornado threat does exist across
far northwest Missouri as strong updrafts continue to tilt horizontal
vorticity into the vertical along the leading edge of the cold pool
as it tracks south and east with time. For now...agree completely with
where SPC has the highest tornado threat /NW MO/ as further progress
to the south and east will likely result in a less favorable
environment due to nocturnal cooling/low-level stabilization effects.
In terms of hydro concerns...have elected to go with a flash flood
watch for much of northwest MO/northeast Kansas as potential exists
for training convection if an outflow boundary lays out across
central Missouri. As alluded to above...strength of developing low-
level jet is a little concerning especially when PWAT values are
expected to increase to anywhere between 2-3 standard deviations
above normal as main front approaches. HPC QPF shows a 2+ inch
bullseye directly west of KC which appears to be in favor of
developing training after midnight. Would rather play it safe hence
the current flash flood watch which runs from 2z this evening through
15z Monday morning.
Front to slowly settle south of the region during the early morning
hrs. Another round of strong to severe storms is possible on
Monday...primarly south of the the greater KC area as daytime
heating combines with still impressive wind fields aloft. For
tomorrow...more optimal timing may support isolated supercell
structures as opposed to tonight/s linear activity. Regardless...have
maintained likely pops for most areas south of I-70 during the
afternoon hrs.
Front to clear the area tomorrow night which should support a mostly
dry Tuesday. Front slowly expected to lift north as a warm front
through the day on Wednesday but minimal impacts expected as no
significant features are at play to enhance upward vertical motion.
Temps by then should begin to rise with low to mid 90s possible
Wednesday afternoon as southerly flow reinvades the area.
.LONG TERM...(Wednesday Evening through Sunday)
Issued at 357 PM CDT SUN AUG 31 2014
A little bit of everything during the extended portion of the
forecast. Storms early Wednesday, followed by a return of hot and
humid air until a cold front and more storms on Friday, then finally
some fall-like weather over the weekend.
Medium range models all on the same page with the overall pattern.
Mid-week zonal flow backs to the southwest in response to an upper
trough tracking east from the Northern Rockies through the Upper MS
Valley by Friday.
Elevated convection associated with a northward returning warm front
will affect the CWA early Wednesday followed by hot and humid air
spreading back into the region. This will likely last into Friday
when the southern extension of the Northern Plains upper trough
forces a cold front south and through the Mid MO River Valley by
Saturday morning. Moderately strong and broad area of high pressure
expanding southward will bring some much needed relief from the high
humidities.
&&
.AVIATION...(For the 18Z TAFS through 18Z Monday Morning)
Issued at 1231 PM CDT SUN AUG 31 2014
VFR conditions this afternoon will give way to increasing chances
for showers and storms by evening as a strong storm system moves
into the area. Right now...initial shwr/storm activity expected to
reach MCI as early as 4z...and STJ as early as 3z. As this moves
in...strong wind gusts may create SQ conditions before strong
convective outflow moves east of area terminals. Shwrs/storms likely
to continue through a good portion of the overnight as low-level jet
increases...and storms continuously redevelop along and north of
thunderstorm outflow. Additional showers and storms possible after
12z...however bulk of activity should be shifting south as main
frontal boundary continues to move through the area.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...FLASH FLOOD WATCH from 9 PM CDT this evening through Monday
morning FOR KSZ025-102>105.
MO...FLASH FLOOD WATCH from 9 PM CDT this evening through Monday
morning FOR MOZ001>005-011>014-020>022-028>030.
&&
$$
SHORT TERM...32
LONG TERM...MJ
AVIATION...32
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1206 PM EDT SUN AUG 31 2014
.SYNOPSIS...
A SLOW MOVING TROUGH OF LOW PRESSURE WILL PRODUCE SHOWERS AND A
FEW THUNDERSTORMS TODAY BEFORE SLOWLY TAPERING OFF FROM NORTHWEST
TO SOUTHEAST THIS AFTERNOON. IT WILL REMAIN MUGGY ALTHOUGH
EXTENSIVE CLOUD COVER WILL KEEP TEMPERATURES LOWER THAN YESTERDAY.
A FEW SPOTTY SHOWERS AND THUNDERSTORMS ARE POSSIBLE ON LABOR
DAY...BUT THE MAJORITY OF THE DAY SHOULD BE RAIN FREE WITH
TEMPERATURES WARMING BACK TO A LITTLE ABOVE AVERAGE.
&&
.NEAR TERM /THROUGH TONIGHT/...
RADAR IMAGERY LATE THIS MORNING SHOWS A SOLID AREA OF RAIN ACROSS
CENTRAL NEW YORK...JUST ABOUT TO EXIT EAST OF OUR CWA. BEHIND
THIS...BROKEN LINES OF SHOWERS WITH EMBEDDED THUNDERSTORMS HAVE
DEVELOPED AHEAD OF A WIND SHIFT BOUNDARY WHICH EXTENDS FROM SW-NE
AND IS LOCATED NEAR BUFFALO AT 1100 AM. THIS BOUNDARY WILL
CONTINUE TO MOVE EAST IN ASSOCIATION WITH A MID LEVEL TROUGH. THE
12Z BUF SOUNDING HAS AN IMPRESSIVE 1.83 INCH PWAT...SO SHOWERS AND
THUNDERSTORMS WHICH DO DEVELOP AHEAD OF THIS BOUNDARY WILL PRODUCE
BRIEF HEAVY DOWNPOURS. FOR THE MOST PART...THE PROGRESSIVE NATURE
OF THE BOUNDARY WILL MITIGATE FLOOD POTENTIAL...HOWEVER A
DEVELOPING AREA OF HEAVY RAIN SHOWERS ACROSS LAKE ERIE MAY HAVE
THE POTENTIAL TO PRODUCE LOCALIZED FLOODING IN CHAUTAUQUA COUNTY
THROUGH MID AFTERNOON.
IT IS STILL FAIRLY MOIST BEHIND THIS BOUNDARY...AND WITH A LAKE
BREEZE CONVERGENCE BOUNDARY EXPECTED TO DEVELOP NEAR THE SOUTH
SHORES OF LAKE ONTARIO THERE COULD BE A FEW SHOWERS OR
THUNDERSTORMS WHICH DEVELOP ON THIS BOUNDARY. HOWEVER...MOST
MESOSCALE GUIDANCE FROM THE HRRR TO NAM/RGEM FOCUS THE STEADIEST
SHOWERS ACROSS EAST OF EACH LAKE...OUT AHEAD OF THE BOUNDARY.
SOUTHWESTERLY WINDS WILL PICK UP ACROSS THE NIAGARA FRONTIER THIS
AFTERNOON...WHICH SHOULD PROVIDE AT LEAST A PARTIAL CLEARING BY
MIXING OUT LOW MOISTURE. TEMPERATURES ALOFT ARE STILL WARM...WITH
SURFACE TEMPERATURES LIKELY TO REACH 80 IN ANY AREAS WHICH GET
PROLONGED SUNSHINE. SOUTHERN AND EASTERN PORTIONS OF THE CWA
SHOULD STAY STUCK IN THE CLOUDS...WITH HIGHS AVERAGING IN THE MID
70S.
TONIGHT SHOWERS ACROSS THE SOUTHERN TIER AND CENTRAL NY WILL
CONTINUE TO SLOWLY DIMINISH. ENOUGH INSTABILITY MAY DEVELOP IN THE
WAKE OF THIS MAIN RAIN AREA TO ALLOW SCATTERED THUNDERSTORMS TO FORM
DURING THE LATE AFTERNOON AND EARLY EVENING ACROSS THE NIAGARA
PENINSULA. IF THEY MATERIALIZE...A FEW MAY MAKE IT INTO AREAS JUST
NORTH OF BUFFALO THIS EVENING. SCATTERED STORMS MAY ALSO FORM OVER
SOUTHEAST ONTARIO AND CROSS THE SAINT LAWRENCE INTO THE NORTH
COUNTRY THIS EVENING. OTHERWISE EXPECT SOME PARTIAL CLEARING
OVERNIGHT ON THE LAKE PLAINS. ACROSS THE HIGHER TERRAIN LOW LEVEL
MOISTURE AND WEAK UPSLOPE FLOW AND CONVERGENCE WILL LIKELY SUPPORT
EXPANDING LOW CLOUD COVER. EXPECT LOWS IN THE MID TO UPPER 60S ON
THE LAKE PLAINS AND LOWER TO MID 60S IN THE SOUTHERN TIER AND NORTH
COUNTRY.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
A WARM AND STICKY AIRMASS WILL REMAIN ACROSS THE REGION ON
MONDAY...WITH MOST OF THE FORECAST AREA EXPERIENCING MAINLY DRY
CONDITIONS. HOWEVER THERE WILL BE THE CHANCE FOR SCATTERED SHOWERS
AND THUNDERSTORMS IN THE AFTERNOON AND EVENING...MAINLY ACROSS THE
INTERIOR SOUTHERN TIER WHERE THE BEST INSTABILITY WILL RESIDE. CAPE
VALUES BY LATER IN THE AFTERNOON ACROSS THIS REGION WILL RUN IN THE
1000-1500 J/KG RANGE WITH LI`S POSSIBLY AS LOW AS -4. HOWEVER WITH
WEAK 0-6KM BULK SHEAR (~20KTS) AND LACK OF A GOOD SURFACE TRIGGER
(ASIDE FROM A POSSIBLE LAKE BREEZE)...NOT EXPECTING ANY
THUNDERSTORMS TO REACH SEVERE LIMITS. INSTABILITY LOOKS LOWER ACROSS
THE REMAINDER OF THE AREA...AND THUS CONVECTIVE CHANCES LOOK MUCH
LOWER AS WELL. TEMPERATURES WILL AGAIN BE ON THE WARM SIDE WITH
HIGHS IN THE UPPER 70S TO LOWER 80S.
WITH THE LOSS OF DAYTIME HEATING MONDAY NIGHT MOST OF THE DIURNALLY
DRIVEN CONVECTION WILL DIMINISH IN COVERAGE...ALTHOUGH A FEW STORMS
MAY CONTINUE LATE INTO THE EVENING...ESPECIALLY ACROSS PORTIONS OF
THE SOUTHERN TIER. AT THE SAME TIME A COLD FRONT OVER THE UPPER
GREAT LAKES WILL BE ADVANCING TOWARD THE REGION AND BE LOCATED WEST
OF NEW YORK STATE BY TUESDAY MORNING. THAT SAID...MOST OF THE NIGHT
LOOKS TO REMAIN DRY...WITH PRECIP CHANCES STARTING TO INCREASE A BIT
ACROSS WESTERN NEW YORK TOWARD TUESDAY MORNING. ANOTHER MILD
NIGHT CAN BE EXPECTED WITH LOWS IN THE MID TO UPPER 60S FOR MOST
LOCATIONS THANKS TO DEEP SOUTHERLY FLOW OUT AHEAD OF THE APPROACHING
COLD FRONT.
LATEST GUIDANCE PACKAGE HAS THE COLD FRONT NOW MOVING A BIT SLOWER
THAN IN PREVIOUS RUNS. THIS IS MOST LIKELY DUE TO MOST OF THE MODELS
NOW COMING INTO AGREEMENT ON THE DEVELOPMENT OF LOW PRESSURE
SOMEWHERE IN THE OHIO VALLEY ALONG THE FRONT AND THEN TRACKING IT
NORTHEAST ALONG THE BOUNDARY WHICH WOULD SLOW IT DOWN A LITTLE.
THAT SAID...IT NOW APPEARS IT WILL TAKE THE BULK OF THE DAY TUESDAY
FOR THE COLD FRONT TO SWEEP ACROSS THE REGION WITH SHOWERS AN
THUNDERSTORMS LIKELY...WITH LOWER CHANCE POPS BY LATER IN THE DAY
ACROSS WESTERN NEW YORK. HIGH PRECIPITABLE WATER VALUES OF 1.7"-1.9"
TUESDAY AFTERNOON OFFER THE RISK OF HEAVY DOWNPOURS WITH ANY
THUNDERSTORM. SBCAPES OVER 1000 J/KG COMBINED WITH LIFTED INDEX
VALUES AT -4C TO -5C ALSO POINT TO THE POSSIBILITY OF STORMS. THE
MAIN DIFFERENCES FROM MONDAY ARE THAT 0-6KM BULK SHEAR VALUES LOOK
TO BE IN THE 40-45KT RANGE...AND ALSO HAVE THE SURFACE COLD FRONT
CROSSING THE FORECAST AREA WHICH WILL SERVE AS THE FOCAL POINT FOR
STORMS TO FIRE ALONG. ALL THIS SAID...LOOKS AS THOUGH THERE COULD BE
SOME STRONG STORMS...WITH A FEW STORMS POSSIBLY REACHING SEVERE
LIMITS. MAIN THREATS APPEAR TO BE GUSTY WINDS ASSOCIATED WITH BOWING
LINE SEGMENTS AND MARGINALLY SEVERE HAIL. ANOTHER WARM DAY ON TAP
WITH HIGHS IN THE UPPER 70S TO LOWER 80S.
THE COLD FRONT WILL SLIDE SOUTH AND EAST OF THE FORECAST AREA
TUESDAY EVENING...TAKING THE SHOWERS AND STORMS WITH IT. ALTHOUGH A
FEW SHOWERS WILL STILL BE POSSIBLE DURING THE EVENING ACROSS EASTERN
AREAS...BUT EVEN HERE THINGS WILL DRY OUT LATER TUESDAY NIGHT AS
SURFACE HIGH PRESSURE STARTS TO BUILD EAST ACROSS NEW YORK STATE.
LOWS WILL BE GENERALLY IN THE UPPER 50S TO LOWER 60S.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
UPPER LEVEL RIDGING AND SURFACE HIGH PRESSURE WILL BUILD ACROSS THE
REGION WEDNESDAY AND THURSDAY BRINGING IN DRIER AIR AND TEMPERATURES
THAT WILL STILL AVERAGE AT OR JUST A BIT ABOVE NORMAL FOR EARLY
SEPTEMBER. HIGH PRESSURE WILL THEN SLIDE OFF THE NEW ENGLAND COAST
BY FRIDAY. THIS WILL PROVIDE MAINLY DRY CONDITIONS THROUGH
MIDWEEK...BEFORE THE NEXT FRONTAL SYSTEM APPROACHES FOR LATE IN THE
WEEK AND EARLY WEEKEND. TEMPERATURES WILL BE A BIT ABOVE SEASONAL
NORMALS WITH HIGHS IN THE UPPER 70S TO LOW 80S AND LOWS IN THE LOWER
60S.
&&
.AVIATION /16Z SUNDAY THROUGH THURSDAY/...
CONDITIONS HAVE LOWERED LATE THIS MORNING...WITH THE APPROACH OF A
SURFACE TROUGH AN IN HEAVIER RAIN SHOWERS. LOW VSBY IN RAIN
SHOWERS...AND A FEW EMBEDDED THUNDERSTORMS SHOULD BE
TEMPORARY. EXPECT A MIX OF MVFR/VFR CIGS AT BUF/IAG/ROC/ART WITH
THE SW WIND SHIFT...WHILE JHW IS LIKELY TO REMAIN IFR OR LOWER AND
THEN IMPROVE WITH THE WIND SHIFT.
TONIGHT ANY SHOWERS AND SCATTERED THUNDER ACROSS THE SOUTHERN TIER
WILL DIMINISH DURING THE EVENING. MAINLY VFR DURING THE EVENING WILL
GIVE WAY TO INCREASING AMOUNTS OF IFR IN LOW STRATUS OVERNIGHT WITH
EXTENSIVE LOW LEVEL MOISTURE FIELDS. EXPECT STRATUS TO FORM FIRST
ACROSS HIGHER TERRAIN...BUT MAY SPREAD TO THE LOWER ELEVATIONS OF
WESTERN NY AS WELL AFTER ABOUT 09Z. AREAS OF FOG AND IFR VSBY ARE
LIKELY ACROSS THE HIGHER TERRAIN OF THE SOUTHERN TIER AND FINGER
LAKES AS WELL WHERE THE LOW STRATUS INTERSECTS THE HILLS.
OUTLOOK...
MONDAY...VFR/MVFR IN SCATTERED SHOWERS AND THUNDERSTORMS.
TUESDAY...SHOWERS AND THUNDERSTORMS LIKELY WITH ASSOCIATED BRIEF
MVFR/IFR. SOME STORMS MAY BE STRONG.
WEDNESDAY AND THURSDAY...VFR.
&&
.MARINE...
MODERATE SOUTHERLIES WILL CONTINUE TO PRODUCE MARGINAL SMALL CRAFT
ADVISORY CONDITIONS AT THE NORTHEAST END OF LAKE ONTARIO FROM GALLOO
ISLAND TO CAPE VINCENT THROUGH EARLY AFTERNOON BEFORE
DIMINISHING. LOW PRESSURE WILL MOVE ACROSS SOUTHERN QUEBEC TODAY
WITH WINDS BECOMING MORE SOUTHWEST ON THE LOWER LAKES. EXPECT
WINDS TO INCREASE ABRUPTLY ON LAKE ERIE THROUGH EARLY
AFTERNOON...WITH A 3 TO 6 HOUR PERIOD OF 15 TO 20 KNOT WINDS AND 3
TO 5 FOOT WAVES AS WINDS ALOFT SHIFT TO THE WSW AND MIX DOWN
AS THEY ENCOUNTER THE CHAUTAUQUA RIDGE. ALSO...THERE IS A
CONVERGENCE BOUNDARY ON LAKE ERIE WHICH HAS THE POTENTIAL TO
PRODUCE WATER SPOUTS THROUGH EARLY AFTERNOON. THIS POTENTIAL WILL
END AS THE BOUNDARY SLIDES FURTHER SOUTH AND OFF THE LAKE.
THE PRESSURE GRADIENT RELAXES ACROSS THE LOWER LAKES TONIGHT AS LOW
PRESSURE DISSIPATES OVER SOUTHEAST QUEBEC. THIS WILL ALLOW WINDS AND
WAVES TO SUBSIDE.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR LEZ040-
041.
SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON
FOR LOZ045.
&&
$$
SYNOPSIS...HITCHCOCK
NEAR TERM...APFFEL/HITCHCOCK
SHORT TERM...JM
LONG TERM...JM/WCH
AVIATION...APFFEL/HITCHCOCK
MARINE...APFFEL/HITCHCOCK
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1235 PM CDT SUN AUG 31 2014
.UPDATE...
ISSUED AT 1227 PM CDT SUN AUG 31 2014
BROAD AREA OF PRECIPITATION HAS PUSHED OFF TO THE EAST. OF TO THE
WEST...SHOWERS ARE STARTING TO RE-DEVELOP WITH THE NEXT WAVE
PUSHING THROUGH BROAD CYCLONIC FLOW. WITH HIT-AND-MISS SHOWER
ACTIVITY EXPECTED...HAVE BROAD BRUSHED LOW POPS FOR LATER THIS
AFTERNOON. UPDATES HAVE BEEN SENT.
UPDATE ISSUED AT 824 AM CDT SUN AUG 31 2014
SHOWER ACTIVITY WITH A FEW WEAK THUNDERSTORMS CONTINUES MAINLY
ALONG AND EAST OF A LINE FROM JAMESTOWN TO HARVEY TO BOTTINEAU.
HAVE ADJUSTED POPS ACCORDINGLY FOR THIS...AND HAVE KEPT SOME LOW
POPS IN THE FAR SOUTHWEST AS SOME WEAK SHOWERS START TO DEVELOP
AND MOVE INTO THAT AREA. HAVE ALSO EXPANDED PATCHY FOG COVERAGE
FOR THE MORNING AS VISIBILITY HAS DROPPED OVER A VARIETY OF
LOCATIONS IN WESTERN NORTH DAKOTA. UPDATES HAVE BEEN SENT.
UPDATE ISSUED AT 633 AM CDT SUN AUG 31 2014
STILL GETTING SOME THUNDERSTORM REDEVELOPMENT ACROSS EAST CENTRAL
NORTH DAKOTA IN STUTSMAN COUNTY. APPEARS THIS WILL TRACK EAST FOR
THE NEXT FEW HOURS. AREAS OF FOG SPREADING ACROSS THE FAR NORTH.
THIS WILL LAST THROUGH MID MORNING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 358 AM CDT SUN AUG 31 2014
FOCUS IN THE SHORT TERM WILL BE ON THE EXITING RAINFALL THROUGH
THIS MORNING AND THE CHANCES FOR RAIN LATER TODAY.
THE HRRR MODEL HAS DONE A DECENT JOB OF FORECASTING PRECIPITATION
THROUGH THE NIGHT AND EARLY THIS MORNING AND POPS MIMIC THE 05 UTC
HRRR PRECIPITATION AS IT PROGRESSES NORTHEAST. MOST ALL HEAVY RAIN
HAS PUSHED EAST INTO EASTERN NORTH DAKOTA...HOWEVER A VERY THIN BAND
OF SHOWERS IS SLOWLY MOVING EAST ACROSS WESTERN NORTH DAKOTA. AS OF
0730 UTC THE BAND DROPPED HEAVY RAIN AT THE DICKINSON AIRPORT. DO
NOT EXPECT THIS BAND...AT LEAST THE HEAVY RAIN ASSOCIATED WITH
IT...TO LAST MUCH LONGER INTO THE MORNING HOURS.
LOOKING FORWARD TO THIS AFTERNOON AND TONIGHT MODELS AGREE ON A
BROAD TROUGH SETTING UP OVER THE NORTHERN PLAINS TODAY WITH A WEAK
SHORT WAVE MOVING THROUGH IN THE AFTERNOON AND NIGHT. THE 00 UTC
MODELS ARE HAVING A DIFFICULT TIME NAILING DOWN WHERE THE
PRECIPITATION WILL FALL EXACTLY...HOWEVER ONLY LIGHT TO MODERATE
SHOWERS ARE EXPECTED. AT THE MOST EXPECTING A SOME SCATTERED SHOWERS
AND A FEW RUMBLES OF THUNDER.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 358 AM CDT SUN AUG 31 2014
THE EXTENDED BEGINS WITH A COOL CYCLONIC FLOW ALOFT ACROSS THE
NORTHERN PLAINS MONDAY INTO TUESDAY. THIS SHOULD AT LEAST SUPPORT
SOME WIDELY SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS. HIGHS
MONDAY AND TUESDAY WILL BE A BIT COOL IN THE UPPER 60S TO LOWER
70S. BY WEDNESDAY THE FLOW ALOFT BECOMES MORE ZONAL AS THE
IN BETWEEN SHORTWAVE TROUGHS. BY THURSDAY THE GFS/ECMWF/GEM BRING
THE NEXT SHORTWAVE TROUGH INTO THE NORTHERN PLAINS WHICH IS
PRETTY CONSISTENT WITH THE PAST FEW MODEL RUNS. THE ECMWF/GEM ARE A
BIT MORE ROBUST IN QPF FORECAST FOR NORTH DAKOTA. LIKED THE
ALLBLEND VERSION OF POPS FOR WEDNESDAY NIGHT AT 30 POPS FOR NOW.
AFTER THURSDAY THE FLOW ALOFT BECOMES SEPARATED BETWEEN A NORTHERN
AND SOUTHERN STREAM FLOW WITH THE GFS MORE PRONOUNCED IN THE FLOW
SEPARATION AROUND A CUTOFF LOW OFF THE WEST COAST. THE BASIC
RESULT WILL BE A QUIET PERIOD FRIDAY INTO SATURDAY AS THE FLOW
MERGES ALOFT OVER THE NORTHERN PLAINS RESULTING IN WEAK SUDSIDENCE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1227 PM CDT SUN AUG 31 2014
ISOLD -SHRA/-TSRA ARE EXPECTED THROUGH MUCH OF THE FORECAST
PERIOD...THOUGH WILL REFRAIN FROM MENTIONING IN INDIVIDUAL
TERMINAL FORECASTS GIVEN THE LOW PROBABILITY OF ANY VIS/CIG
RESTRICTIONS. WILL MONITOR AND UPDATE AS NEEDED. MVFR CIGS WILL
CONTINUE TO AFFECT THE KJMS TERMINAL THROUGH EARLY AFTERNOON.
OTHERWISE...VFR CONDITIONS ARE EXPECTED.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JJS
SHORT TERM...MM
LONG TERM...WAA
AVIATION...JJS
AREA FORECAST DISCUSSION
NWS ABERDEEN SD
331 PM CDT SUN AUG 31 2014
.SHORT TERM...TONIGHT THROUGH TUESDAY NIGHT
POTENT SHORTWAVE EVIDENT ON WATER VAPOR OVER WYOMING. AHEAD OF
THIS WAVE...OMEGA AND UPPER JET MAX HELPING TO MAINTAIN BAND OF
RAINFALL THAT HAS TREKKED FROM SOUTH CENTRAL SD TO NORTHEAST SD
OVER THE PAST SEVERAL HOURS. HAVE BEEN ADJUSTING POPS FOR THIS
BAND OF RAIN AS IT APPEARS IT WILL SURVIVE MOST IF NOT ALL THE WAY
ACROSS THE CWA. HRRR PICKING UP ON THIS QUITE NICELY.
OVERNIGHT...EXPECTING SCATTERED SHOWERS AND STORMS TO MOVE EAST
ACROSS THE STATE BUT WITH MINIMAL SEVERE THREAT DUE TO LACK OF
INSTABILITY. ONLY QUESTION IS THE DEGREE OF AREAL COVERAGE OF
PRECIP. SOME MODELS GREATER THAN OTHERS...WITH THE HRRR
PARTICULARLY DRY AND SORT OF THE OUTLIER. MOST OTHER MODELS HAVE
ACTIVITY MOVING ACROSS AT LEAST THE SOUTHERN HALF OF SD TONIGHT.
HAVE ADJUSTED POPS ACCORDINGLY AND LINGERED THEM A BIT LONGER
THROUGH THE NIGHT AS NSSL WRF STILL SHOWS CONVECTIVE CLUSTERS OVER
SOUTHEAST SD AT 09Z TONIGHT.
A WEAKER WAVE MOVES ACROSS THE AREA MONDAY...BUT SHOULD STILL
PROVIDE FOR A FEW SCATTERED SHOWERS OR STORMS. AREAL COVERAGE DOES
NOT APPEAR IT WILL QUITE MATCH UP TO WHATS MOVING INTO WESTERN SD
RIGHT NOW...BUT WORTHY OF 20/30 POPS NONETHELESS. AGAIN A LACK OF
INSTABILITY TOMORROW SO SEVERE THREAT IS VERY LOW.
TUESDAY STILL LOOKS DRY WITH NO NOTABLE SYSTEMS IN THE AREA. 500
MB HEIGHTS RISE SLOWLY THROUGH THE DAY WITH WARM AIR ADVECTION
DEVELOPING. HIGHS WILL BUMP UP INTO THE UPPER 70S TO LOW 80S FOR
MOST AREAS.
.LONG TERM...WEDNESDAY THROUGH SUNDAY
THE EARLY PART OF THE PERIOD STARTS OFF SOMEWHAT ACTIVE AS FAIRLY
STRONG SYSTEM MOVES ACROSS THE NORTHERN PLAINS. LATEST MODELS ARE
IN FAIR AGREEMENT ON AVAILABLE MOISTURE/INSTABILITY BUT DO SUGGEST
CAPPING MIGHT FORCE MOST ACTIVITY TO REMAIN NORTH OF THE CWA
WEDNESDAY NIGHT INTO THURSDAY AS COLD FRONT MOVES EAST. THUS POPS
NO HIGHER THAN CHC NEEDED AT THIS POINT. BEHIND THE FRONT IT
LOOKS FAIRLY DRY FROM THURSDAY THROUGH SUNDAY AS HIGH PRESSURE
PROVES DOMINANT. TEMPERATURES WILL START OFF ABOVE NORMAL AT THE
BEGINNING OF THE PERIOD THEN TREND TOWARD NORMAL OR EVEN BELOW BY
THE END OF THE WEEK.
&&
.AVIATION...
18Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
WHATEVER LEFTOVER MVFR CIGS ARE HANGING AROUND SHOULD DISSIPATE
THIS AFTERNOON. AN AREA OF RAIN/SHOWERS ASSOCIATED WITH AN MCV IS
LIKELY TO AFFECT KPIR/KATY/KABR THIS AFTERNOON INTO THE EARLY
EVENING HOURS. OVERALL VFR CONDITIONS ARE EXPECTED LATER THIS
AFTERNOON THROUGH TONIGHT.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
SHORT TERM...TMT
LONG TERM...TDK
AVIATION...TDK
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1244 PM CDT SUN AUG 31 2014
.UPDATE...
AVIATION DISCUSSION UPDATED BELOW.
SOMEWHAT DIFFICULT FORECAST SHAPING UP FOR TODAY WITH A FEW
UNCERTAINTIES. FAIRLY POTENT SHORTWAVE TROUGH CROSSING WYOMING AT
THIS TIME. SFC COLD FRONT IT MAKING ITS WAY THROUGH THE EASTERN
CWA AND IS ALMOST AT THE SD/MN BORDER. AREA OF RAIN MOVING
NORTHEAST ACROSS SOUTH CENTRAL SD. MADE A FEW CHANGES TO THE
FORECAST FOR TODAY BASED ON CURRENT MODEL AND RADAR TRENDS. FIRST
OFF...SEVERE THREAT LOOKS TO BE EAST OF THE CWA TODAY AND LATEST
DAY ONE SEVERE OUTLOOK HAS SHIFTED EAST. FRONTAL PASSAGE SPEED
LIKELY PUTS BEST SEVERE POTENTIAL FROM MINNESOTA THROUGH IOWA AND
INTO NEBRASKA. HAVING SAID THAT THOUGH...STILL EXPECTING
ADDITIONAL SHOWER AND STORM DEVELOPMENT ACROSS WESTERN/CENTRAL SD
LATER THIS AFTERNOON...THEN SPREADING EAST INTO THE EVENING.
MODELS PICKING UP ON THIS...AND HRRR ACTUALLY HAVING A GOOD
REPRESENTATION OF CURRENT CONDITIONS AND MAY BE LATCHING ONTO
SOMETHING FOR LATER TODAY. BASICALLY...IT WOULD APPEAR MUCH OF THE
CWA IS QUIET TODAY...ESPECIALLY THE NORTHEAST. BUT BY THIS
AFTERNOON AND EVENING COULD SEE AN INCREASE IN SHOWER AND STORM
COVERAGE. ADJUSTED POPS ACCORDINGLY BUT STILL SOME UNCERTAINTY
HERE. NEED TO WATCH AREA OF RAIN MOVING TOWARDS PIERRE TO SEE IF
IT HOLDS TOGETHER OR EXPANDS. CONCERNING TODAYS TEMPS...ANOTHER
GREY AREA AS ABUNDANT MID LEVEL CLOUDS STREAMING INTO THE REGION
MAY KEEP TEMPS DOWN A FEW DEGREES. ALSO DEALING WITH A STRATUS
DECK OVER THE NORTHERN CWA IN WHICH ITS RESIDENT TIME OVER THE
AREA IS QUESTIONABLE. FURTHER ADJUSTMENTS TO POPS/TEMPS LIKELY
NEEDED THROUGHOUT THE DAY.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH TUESDAY
WARM ADVECTION/LOW LEVEL JET LINE OF STORMS PUSHING RAPIDLY TO THE
EAST/NORTHEAST. THE SURFACE LOW IS POSITIONED BACK TOWARDS THE MO
RIVER...AND THE UPPER TROF AXIS IS POSITIONED BACK IN WY. WHILE
THE SURFACE LOW/TROF IS EXPECTED TO PUSH INTO THE FAR EASTERN
CWA...COOLER AIR ALOFT WILL HELP DESTABILIZE THE ATMOSPHERE ACROSS
THE REGION. THE FAR EASTERN CWA WILL CONTINUE TO SEE A FAVORABLE
SHEAR PROFILE FOR SEVERE WEATHER...AND THE REST OF THE CWA WILL
REMAIN CONVECTIVELY UNSTABLE. LOSS TO DAYTIME HEATING WILL REMOVE
THE THREAT OF STORMS...HOWEVER CLOUDS AND LIGHT SHOWERS MAY
PERSIST AS THE UPPER TROF REMAINS OVERHEAD. A SECONDARY SHORTWAVE
MOVES IN MONDAY EVENING...WITH ANOTHER ROUND OF CONVECTION.
AS FOR TEMPERATURES...LOOK FOR HIGHS IN THE 70S BOTH TODAY AND
MONDAY. TUESDAY WILL SEE WARMER READINGS UNDER A WARM ADVECTION
REGIME.
.LONG TERM...TUESDAY NIGHT THROUGH SATURDAY
THE MODELS AGREE WELL IN THE LONG TERM WITH KEEPING IT MAINLY DRY
ALONG WITH A COOL DOWN. THE PERIOD BEGINS WITH AN UPPER LOW PRESSURE
TROUGH DROPPING INTO THE PACIFIC NORTHWEST ON TUESDAY NIGHT. THIS
THEN TRACKS ALONG THE CANADIAN BORDER INTO THURSDAY. AT THE
SURFACE...A LOW PRESSURE AREA AND COOL FRONT SWEEP FROM NORTHWEST
TO SOUTHEAST ACROSS OUR REGION FROM TUESDAY NIGHT INTO THURSDAY.
THUS...WARMER AIR AND SUNSHINE IN ADVANCE OF THIS WILL BRING ABOVE
NORMAL TEMPERATURES TO THE CWA FOR WEDNESDAY WITH HIGHS IN THE 80S
TO AROUND 90 DEGREES IN THE SOUTHWEST CWA. AS THE SURFACE LOW PRESSURE
AREA/COOL FRONT PUSH ACROSS THE REGION FOR THURSDAY INTO FRIDAY...
TEMPERATURES WILL COOL TO MAINLY THE 70S FOR FRIDAY CONTINUING
INTO SATURDAY. SURFACE HIGH PRESSURE LOOKS TO BE IN CONTROL OF THE
WEATHER FROM THURSDAY THROUGH SATURDAY. HAVE IN A FEW CHANCES OF
SHOWERS/STORMS THROUGH THE PERIOD MAINLY EARLY WITH THE SURFACE
LOW AND COOL FRONT.
&&
.AVIATION...
18Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
WHATEVER LEFTOVER MVFR CIGS ARE HANGING AROUND SHOULD DISSIPATE
THIS AFTERNOON. AN AREA OF RAIN/SHOWERS ASSOCIATED WITH AN MCV IS
LIKELY TO AFFECT KPIR/KATY/KABR THIS AFTERNOON INTO THE EARLY
EVENING HOURS. OVERALL VFR CONDITIONS ARE EXPECTED LATER THIS
AFTERNOON THROUGH TONIGHT.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...TMT
SHORT TERM...CONNELLY
LONG TERM...MOHR
AVIATION...TDK
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
251 PM EDT SUN AUG 31 2014
.SHORT TERM...(TONIGHT THROUGH TUESDAY)...AIR MASS WAS SLUGGISH TO
DE-STABILIZE THIS AFTERNOON DUE TO EXTENSIVE CLOUD COVER. HOWEVER
STARTING TO SEE SCATTERED CONVECTION (SOMEWHAT STRONG) DEVELOP
OVER NE AL AND SRN PLATEAU...WHERE MESO PAGE SHOWS 30 KTS OF SHEAR.
BASED ON THIS NEW ACTIVITY WENT IN LINE WITH LATEST HRRR AND RAP
MODELS. THUS...KEPT A SLIVER OF LIKELY POPS FOR LATE AFTERNOON
ACROSS SEQUATCHIE VALLEY AND NRN PLATEAU COUNTIES.
OTHERWISE...FOR THIS EVENING...CARRIED CHANCE POPS FROM W TO E
ACROSS THE FORECAST AREA WITH HIGHER CHANCES WEST. DROPPED BACK TO
MOSTLY SLIGHT CHANCE POPS AFTER MIDNIGHT AND ALLOWED FOR PATCHY FOG
AREAWIDE LATE.
RIDGING IS NOTED BRIEFLY ACROSS THE REGION FOR MONDAY AND MONDAY
NIGHT...BEFORE MODELS ADVERTISE ANOTHER APPROACHING SHORTWAVE FOR
TUESDAY. LOWERED POPS A BIT MORE FOR MONDAY AND CARRIED JUST
MINIMAL POPS IN HIGHER TERRAIN AREAS FOR MONDAY EVENING. CHANCE
POPS FOR NOW ON TUESDAY...MORE LIKELY IN THE AFTERNOON. I THINK
FOG COULD BE MORE OF AN ISSUE MONDAY NIGHT GIVEN AN APPARENT LACK
OF CONVECTIVE DEBRIS CLOUDS.
FOR TEMPS...MOS MINS CLOSE AND GENERALLY FOLLOWED. FAVORED THE
WARMER MAXES MONDAY AND STAYED A BIT BELOW THE WARMER GFS MAXES ON
TUESDAY.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)...A WEAK FRONTAL BOUNDARY
IS PROGGED TO DROP SOUTH ACROSS THE VIEWING AREA WEDNESDAY INTO
THURSDAY GENERATING A LITTLE BETTER CHANCE FOR SOME SHOWERS AND
THUNDERSTORMS ACROSS THE REGION. THE MODELS DON`T SHOW MUCH DRYING
AND STABILIZING BEHIND THIS WEAK FEATURE SO KEPT CHANCE POPS FOR
CONVECTION GOING AREA WIDE ON FRIDAY AND SATURDAY. ANOTHER LOW
AMPLITUDE UPPER TROUGH PASSAGE ACROSS THE NORTHEASTERN QUARTER OF
THE COUNTRY HAS BEEN MODELED FOR LATE IN THE WEEKEND SO RAISED POPS
IN THE CHANCE CATEGORY FOR SUNDAY AS A SURFACE COOL FRONTAL BOUNDARY
ACCOMPANIES THE UPPER FEATURE.
&&
.PRELIMINARY POINT TEMPS/POPS...
CHATTANOOGA AIRPORT, TN 69 93 71 92 / 30 20 10 30
KNOXVILLE MCGHEE TYSON AIRPORT, TN 69 90 69 90 / 30 10 10 30
OAK RIDGE, TN 68 91 69 90 / 40 10 10 30
TRI CITIES AIRPORT, TN 66 90 63 89 / 30 10 10 30
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
TG
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
111 PM CDT SUN AUG 31 2014
.DISCUSSION...
18Z AVIATION DISCUSSION.
&&
.AVIATION...
A BROAD LIGHT RAIN SHIELD WITH EMBEDDED STORMS EXTENDING FROM THE
MATAGORDA BAY REGION COUNTIES NORTHEAST ACROSS NORTHERN GALVESTON
BAY AND INTO THE PINEY WOODS...MORE DISCRETE CELLS PASSING ACROSS
KUTS AND KCLL THIS HOUR. RAIN WILL BE ENDING THROUGH THE DAY...THIS
LULL WILL PERSIST THROUGH EARLY MONDAY MORNING WHERE RETURN NEAR-
COASTAL/GULF PRECIPITATION RE-DEVELOPS AND MOVES INLAND PAST SUNRISE.
IF NOT WITHIN RAINS/STORM...VFR CEILINGS/VSBY. PERIODS OF OVERNIGHT
MVFR/IFR DECKS...OR VSBY-REDUCING HZ/FOG...OVER MORE RURAL AREAS
DUE TO A WEAK WIND AND WET GROUND. AREAL SHRA/TSRA COVERAGE MAY
NOT BE AS WIDESPREAD AS TODAY...BUT THE FORECAST IS FOR RETURN
MORE DISCRETE CELLS LATE MONDAY MORNING INTO EARLY AFTERNOON
ACTIVITY...OR AS SOUTHERN COUNTY CONVECTION ADVANCES INTO A MID-
UPPER 80F WARMED INTERIOR AIR MASS. 31
&&
.PREV DISCUSSION... /ISSUED 1014 AM CDT SUN AUG 31 2014/
UPDATE...
SEE MORNING UPDATE.
DISCUSSION...
AT 9 AM...A WEAK TROUGH OR PERHAPS AN OUTFLOW EXTENDS FROM ABOUT
LEAGUE CITY TOM PALACIOS. MOISTURE IS PLENTIFUL AT 850 MB WITH DEW
PTS AT 16-17 C. AT 700 MB...A WEAK TROUGH EXTENDED FROM ABOUT
WHARTON TO MCALLEN WITH A WELL DEFINED 700 MB TROUGH AXIS
EXTENDING FROM ABOUT ST LOUIS TO TEXARKANA TO AUSTIN. AT 250
MB...A WELL DEFINED TROUGH AXIS EXTENDS FROM SE OK INTO CENTRAL
TEXAS. THE LIFT PROVIDED BY THE MID LEVEL TROUGHS AND DEEP
MOISTURE WILL SET THE STAGE FOR ADDITIONAL SHRA/TSRA THROUGH THE
MORNING. 12Z SOUNDINGS SHOW PW VALUES BETWEEN 2.2 AND 2.3
INCHES...NO CAPPING AND CONVECTIVE TEMPS IN LOWER 80S. RADAR IS
SHOWING A SWATH OF RAINFALL MAINLY ALONG AND EAST OF US HWY 59.
1 TO 3 INCHES OF RAIN HAS FALLEN OVER PARTS OF MATAGORDA AND
BRAZORIA COUNTIES WITH A BIT MORE ON THE WAY THIS MORNING. MODELS
INITIALIZED FAIRLY WELL SO AM EXPECTING THE RAINFALL TO CONTINUE
TO MOVE EAST AND NORTH THROUGH THE MORNING WITH RAINFALL BEGINNING
TO DIMINISH BY EARLY THIS AFTN. CURRENT FCST LOOKS ON TRACK BUT
MAY TWEAK TEMPS DOWN A BIT IN THE RAIN COOLED AIR. 43
&&
PREV DISCUSSION... /ISSUED 644 AM CDT SUN AUG 31 2014/
DISCUSSION...
SEE AVIATION FOR 12Z TAF DISCUSSION.
AVIATION...
BAND OF SHRA WITH A FEW ISOLATED TSRA EMBEDDED CONTINUES TO LIFT
SLOWLY NORTHWARD ALONG THE US 59 CORRIDOR. HI RES MODELS INDICATE
THIS ACTIVITY WILL CONTINUE TO SPREAD NORTHWARD THROUGH THE DAY
AND FILL IN FURTHER EAST. BEST COVERAGE AND TSRA CHANCES LOOK TO
REMAIN ALONG AND WEST OF INTERSTATE 45 WITH COVERAGE DIMINISHING
BY LATE AFTERNOON. LOW CLOUDS REDEVELOP AFTER MIDNIGHT WITH MVFR
CIGS POSSIBLE BY DAYBREAK ON MONDAY. 38
&&
PREV DISCUSSION... /ISSUED 439 AM CDT SUN AUG 31 2014/
DISCUSSION...
ALTHOUGH THERE WAS PLENTY OF TROPICAL MOISTURE AND LIFT FROM AN
UPPER LEVEL TROUGH AXIS...THE MAJORITY OF CONVECTION FORMED IN THE
GULF OF MEXICO AND MOVED INTO E TX AND SW LA. LAKE CHARLES ENDED
UP WITH 7.87 INCHES OF RAIN FOR YESTERDAY. THERE IS A SIMILAR
ENVIRONMENT IN PLACE TODAY WITH TROPICAL MOISTURE STILL OVER MUCH
OF SE TX AND UPPER TX COAST. THE TROUGH AXIS IS SLOWLY WEAKENING
BUT STILL COULD BE A FOCUS FOR CONVECTIVE ACTIVITY. BOTH 00Z
LCH/CRP SOUNDINGS SHOWED 2.2 INCHES OF PRECIP WATER AND GOES
SOUNDER DATA ALSO DEPICTS A SWATH OF TROPICAL MOISTURE STRETCHING
SW TO NE ACROSS THE TX COAST. BASED ON WATER VAPOR IMAGERY TROUGH
AXIS SHOULD BE MOVING OUT OF THE AREA AS UPSTREAM SHORT WAVE
TROUGH MOVES ACROSS THE ROCKIES AND INTO THE PLAINS LATER
TODAY/TONIGHT. THIS SHOULD ALSO HELP ADVECT TROPICAL MOISTURE OVER
THE REGION THIS MORNING AND AFTERNOON. HI RES MODELS WRF-
ARW/RAP/HRRR DEVELOP CONVECTION ALONG THE UPPER TX COAST AND MOVE
IT INTO THE COASTAL COUNTIES AROUND 12Z THIS MORNING. RADAR
ALREADY SHOWING SOME SHOWER ACTIVITY FROM MATAGORDA BAY AND
OFFSHORE. THIS SEEMS TO BE MATCHING THE TRENDS IN THE SHORT RANGE
HI RES MODELS. THE NAM/GFS/ECMWF ALSO SUPPORT THE IDEA OF A SWATH
OF PRECIP EMBEDDED WITHIN MAIN TROPICAL MOISTURE AXIS. DECIDED TO
KEEP MENTION OF 60 POPS. AGAIN WITH THIS MUCH MOISTURE STRONGER
STORMS WILL BE CAPABLE OF 1-2 INCHES OF RAIN AN HOUR. ACCUMULATED
PRECIP TOTALS FROM 06Z HRRR SHOW SWATH OF 2-4 INCHES OF RAIN BY
21Z THIS AFTERNOON SO ISOLATED HIGHER AMOUNTS OF RAIN WILL BE
POSSIBLE. MODELS DO INDICATE RAINFALL COMING TO AN END LATE
AFTERNOON AND EVENING SO DECREASED RAIN CHANCES FOR THE AFTERNOON.
OVERALL MOISTURE TRENDS IN NAM/GFS KEEP NEARLY 2 INCHES OF PRECIP
WATER OVER THE TX COAST THROUGH THE MIDDLE OF THE WEEK. A TROPICAL
WAVE IN THE NW CARIBBEAN SHOULD BE MOVING ACROSS THE YUCATAN TODAY
AND TOMORROW. NHC GIVES THIS WAVE A 50 PERCENT CHANCE OF BECOMING
A TROPICAL CYCLONE OVER NEXT 5 DAYS. ITS BEST CHANCE TO DO SO PER
LATEST MODEL GUIDANCE WILL NOT BE UNTIL IT EMERGES IN THE GULF.
EVEN THEN ONLY THE NAM REALLY DEVELOPS THE SYSTEM INTO A CLOSED
CIRCULATION. THE GFS/ECMWF KEEP IT AS AN OPEN WAVE WHICH HAS BEEN
WAY MORE CONSISTENT THAN THE NAM. OVERALL IMPACT TO TX WILL BE TO
KEEP A FETCH OF DEEP MOISTURE OFF THE GULF IN PLACE. THIS SHOULD
ALLOW FOR DAILY RAIN CHANCES FOR THE NEXT WEEK WITH DAY TIME
HEATING DRIVING CONVECTIVE TRENDS. COVERAGE IN CONVECTION WILL BE
THE REAL ISSUE AS GLOBAL MODELS ESTABLISH A BROAD ELONGATED UPPER
LEVEL RIDGE OVER MUCH OF THE SOUTHERN U.S. THE STRENGTH OF THE
RIDGE IS ALSO A QUESTION SO DIFFICULT TO GAGE HOW MUCH SUBSIDENCE
WILL BE OCCURRING DUE TO THE RIDGE. WITH THESE FACTORS IN MIND THE
FORECAST WILL KEEP AT LEAST SOME MENTION OF THUNDERSTORMS EACH
DAY. IT LOOKS LIKE THE HIGHER RAIN CHANCES WILL BE TUE/WED AS THIS
IS WHEN TROPICAL MOISTURE FROM THE TROPICAL WAVE MAY IMPACT THE
AREA. FORECAST WILL GO WITH 30/40 POPS FOR THESE DAYS WITH 20 POPS
FOR THE REST OF THE WEEK.
TEMPERATURES FOR THE WEEK WILL BE ABOVE NORMAL BUT STILL THE MORE
TYPICAL SUMMER TIME TEMPERATURES. MIN TEMPS IN THE MID/UPPER 70S
WILL BE EXPECTED WITH MAX TEMPS IN THE LOW/MID 90S. TEMPS WILL BE
GREATLY INFLUENCED BY CONVECTION AND RESULTING CLOUD COVER. AS IT
STANDS...WITH 100F NOT EXPECTED FOR A HIGH TEMPERATURE AT KCLL OR
KIAH TODAY...THE STREAK OF NOT REACHING 100F FOR A HIGH
TEMPERATURE CONTINUES INTO SEPTEMBER. HOPEFULLY IT STAYS THAT WAY
FOR THE REST OF THE YEAR. 39
&&
MARINE...
SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP THIS
MORNING ACROSS THE COASTAL WATERS AS DEEP TROPICAL MOISTURE MOVES
BACK INTO THE REGION. EXPECT ONSHORE FLOW TO PERSIST THROUGH MUCH
OF THE UPCOMING WEEK. WIND SPEEDS WILL INCREASE LATE MONDAY NIGHT
INTO TUESDAY AND CAUTION FLAGS MAY BE NEEDED FOR THE COASTAL
WATERS. 38
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 76 95 76 95 76 / 10 20 10 20 10
HOUSTON (IAH) 77 93 77 93 77 / 10 30 20 30 10
GALVESTON (GLS) 81 89 82 89 81 / 10 30 30 40 20
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...43
AVIATION/MARINE...31
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SYNOPSIS...
ISSUED AT 218 PM CDT SUN AUG 31 2014
WARM AND RATHER HUMID WITH SHOWERS AND THUNDERSTORMS AT TIMES FOR
THE REST OF THE HOLIDAY WEEKEND AND THROUGH THE UPCOMING WORK
WEEK.
STG SUBTROPICAL RIDGE ACRS THE SRN CONUS WL EXPAND NWD A BIT AS
SOMEWHAT PROGRESSIVE BAND OF WESTERLIES GRADUALLY RECEDES NWD
DURING THE PERIOD. NOTHING SPECIAL ABOUT THIS PATTERN FOR THIS
TIME OF YEAR...AS THE WESTERLIES ARE TYPICALLY STRONGER THAN
DURING THE MIDDLE SUMMER...BUT ARE STILL USUALLY CENTERED N OF THE
AREA.
THE PRIMARY FRONTAL ZONE SEPARATING WARM AND VERY MOIST TROPICAL
AIR TO THE S FM COOLER AND DRIER CANADIAN AIR TO THE N WL REMAIN
STETCHED OUT W-E ALONG THE SRN EDGE OF THE MAIN WESTERLIES...AND
CLOSE TO THE FCST AREA MUCH OF THE TIME. THIS WL RESULT IN
SEVERAL OPPORTUNITIES FOR PCPN...LIKELY RESULTING IN ABV NORMAL
AMNTS. TEMPS ARE EXPECTED TO REMAIN AOA NORMAL FOR MUCH OF THE
FCST PERIOD BEFORE DROPPING BACK CLOSE TO NORMAL LATE. IT WILL
ALSO BE HUMID AT TIMES.
&&
.SHORT TERM...TONIGHT AND MONDAY
ISSUED AT 218 PM CDT SUN AUG 31 2014
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW LOW
PRESSURE MOVING NORTHEAST OVER FAR NORTHWEST MINNESOTA AND A COLD
FRONT MOVING EASTWARD FROM THE LOW TO THE CENTRAL GREAT PLAINS.
STORMS HAVE BEGUN TO FIRE ALONG THE FRONT OVER SOUTH CENTRAL
MINNESOTA...BUT THE ATMOSPHERE IS STRUGGLING TO DESTABILIZE DUE IN
PART TO A PRONOUNCED CAP AND DRY AIR ON THE 18Z MINNEAPOLIS
SOUNDING. HOWEVER...AS A SHORTWAVE OVER NEBRASKA MOVES INTO THE
NORTHERN MISSISSIPPI VALLEY...THE CAP IS EXPECTED TO WEAKEN LATE
THIS AFTERNOON THAT WILL RESULT IN A FAVORABLE ENVIRONMENT FOR
SEVERE STORMS. THESE STORMS COULD MOVE INTO NORTH-CENTRAL WISCONSIN
LATER THIS EVENING. THE MAIN SHORTWAVE IS MOVING EAST OVER EASTERN
WYOMING AND ANTICIPATED TO ARRIVE INTO WISCONSIN LATE TONIGHT INTO
MONDAY MORNING...ALONG WITH THE COLD FRONT. THUNDERSTORM TIMING AND
IMPACTS ARE THE MAIN FORECAST CONCERNS.
TONIGHT...A COLD FRONT WILL SLOWLY MOVE ACROSS THE NORTHERN
MISSISSIPPI VALLEY AS IT WAITS FOR A SHORTWAVE OVER WYOMING TO GIVE
IT A FORWARD PUSH. ASSUMING STRONG TO SEVERE CONVECTION AHEAD OF
THE FRONT DEVELOPS AS PLANNED LATER THIS AFTERNOON INTO THIS
EVENING...GUIDANCE SUGGESTS THIS CONVECTION WILL MAKE A RUN AT
NORTH-CENTRAL WISCONSIN LATE THIS EVENING...THOUGH WILL BE WEAKENING
AS DIURNAL INSTABILITY IS LOST. MODELS SUGGEST AROUND 1000 J/KG OF
ELEVATED CAPE WILL BE PRESENT AS THIS CONVECTION APPROACHES THE
NORTHWEST FORECAST AREA SO NOT OUT OF THE QUESTION THAT A FEW STRONG
STORMS COULD REACH NORTH-CENTRAL WISCONSIN. AN ISOLATED SEVERE
STORM CANNOT BE RULED OUT...MAINLY FOR DAMAGING WINDS AND LARGE
HAIL. WOULDNT BE SURPRISE TO SEE A FEW HOUR BREAK OVERNIGHT BETWEEN
THIS CONVECTION AS IT WEAKENS/LIFTS TO THE NORTHEAST...AND A MORE
WIDESPREAD AREA OF SHOWERS AND THUNDERSTORMS AHEAD OF THE MAIN
SHORTWAVE WHICH WILL MOVE INTO THE NORTHERN MISSISSIPPI VALLEY BY
12Z. THIS AREA OF PRECIP SHOULD MOVE ACROSS CENTRAL AND
NORTH-CENTRAL WI LATE TONIGHT. ELEVATED CAPES LOOK TO BE APPROX 500
J/KG SO NOT ANTICIPATING SEVERE CONVECTION. LOWS MAINLY IN THE
MIDDLE 60S.
MONDAY...THE SHORTWAVE TROUGH WILL LIFT NORTHEAST ACROSS WISCONSIN
MONDAY MORNING...DRIVING THE AREA OF SHOWERS AND THUNDERSTORMS
ACROSS NORTH-CENTRAL AND NORTHEAST WISCONSIN. THE HEAVIEST RAINFALL
LOOKS TO OCCUR OVER CENTRAL AND NORTH-CENTRAL WISCONSIN WITH THIS
EVENT AND COULD SEE AN INCH TO 1.50 INCHES IF CONVECTION REACHES
INTO THIS AREA THIS EVENING. WITH PRECIPITATION OCCURRING DURING
THE MORNING AND THE SHORTWAVE LIFTING NORTHEAST OF THE AREA IN THE
AFTERNOON...SEEMS LIKE AN AWFULLY SMALL TIME PERIOD FOR
REDEVELOPMENT OF STORMS ALONG THE COLD FRONT OVER NORTHEAST
WISCONSIN. THE BEST BET MAY BE TO HAVE STORMS CONTINUOUSLY REFIRE
ALONG THE TAIL OF THE SHORTWAVE...BUT THIS ADMITTEDLY SEEMS LIKE
A SMALL CHANCE SINCE THE ATMOSPHERE WILL HAVE BEEN WORKED OVER
BY THIS TIME...AND PRECIPITATION WILL HAVE SQUASHED SURFACE BASED
INSTABILITY. AS A RESULT...SPC HAS SHIFTED THE SLIGHT RISK OF
SEVERE WEATHER TO THE SOUTH AND EAST OF THE FORECAST AREA AND THIS
SEEMS REASONABLE. WILL MENTION THE CHANCE OF GUSTY WINDS AND SMALL
HAIL BUT LEAVE THE THREAT OF SEVERE WEATHER OUT OF THE HWO.
.LONG TERM...MONDAY NIGHT THROUGH SUNDAY
ISSUED AT 218 PM CDT SUN AUG 31 2014
SOME LINGERING PCPN WL BE POSSIBLE MON EVENING...MAINLY OVER E-C
WI. CARRIED CHC POPS INTO THE EARLY EVENING. WHILE ISOLD SHRA
COULD LINGER WELL INTO THE NGT...THE MAIN POOL OF INSTABILITY WL
BE WELL S BY THEN...SO OPTED TO GO WITH A DRY FCST AFTER MIDNIGHT.
LATER SHIFTS MAY NEED TO TAKE ANOTHER LOOK AT THAT.
THERE ARE PROS AND CONS FOR PCPN CHCS TUE. ON ONE HAND...UPR TROF
WL STILL BE ACRS THE AREA DURING THE MORNING...AND WNWLY UPR FLOW
WL KEEP MODEST MID-LVL LAPSE RATES ACRS THE RGN. ON THE OTHER...
UPR HEIGHTS WL BE RISING AS THE TROF SHIFTS E...AND QG FORCING
WL BE FAVORING SUBSIDENCE. OPTED TO KEEP FAIRLY LOW POPS...BUT
WENT WITH ISOLD SHRA ACRS ALL BUT THE FAR SRN PART OF THE AREA.
PCPN UNLIKELY TO BE A BIG DEAL...BUT CONFIDENCE IN TOTALLY DRY DAY
ISN/T THAT GREAT EITHER.
UPR HEIGHTS SHOULD CONT TO RISE TUE NGT/WED. STAYED DRY TUE NGT...
BUT N-C WI WL BE CLOSE ENOUGH TO THE RETURN FLOW TO JUSTIFY
HAVING A CHC OF TSRA WED.
WENT WITH A BLEND OF TOP PERFORING GUIDANCE PRODUCTS FOR TEMPS...
WHICH WERE DOMINATED BY THE ECMWF AND IT/S MOS AND BIAS-CORRECTED
DERIVATIVES.
NO SIG CHGS NEED TO BROAD-BASED EXTENDED FCST INITIALIZATION
GRIDS.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1158 AM CDT SUN AUG 31 2014
MVFR AND IFR STRATUS NORTH OF A WARM FRONT WILL EVENTUALLY IMPROVE
AT THE AREA TAF SITES EARLY TO MID AFTERNOON. AS A FRONT MOVES
ACROSS THE REGION LATE TONIGHT INTO MONDAY...SCATTERED MVFR CIGS AND
VSBYS...LOCALLY IFR...WILL DEVELOP DUE TO HEAVY RAIN AND POSSIBLE
THUNDERSTORMS. SOME STORMS MAY CONTAIN STRONG GUSTY WINDS AS THEY
MOVE INTO CENTRAL AND NORTH-CENTRAL WISCONSIN LATE IN THE EVENING
AND OVERNIGHT....BUT WITH UNCERTAINTY TIMING/COVERAGE...HAVE LEFT
PRECIP AS SHOWERS.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS.......SKOWRONSKI
SHORT TERM.....MPC
LONG TERM......SKOWRONSKI
AVIATION.......MPC