Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 05/13/15
AREA FORECAST DISCUSSION
NWS PUEBLO CO
930 PM MDT TUE MAY 12 2015
.UPDATE...
ISSUED AT 918 PM MDT TUE MAY 12 2015
UPDATED FORECAST TO REFINE TIMING OF POPS THROUGH THE OVERNIGHT
HOURS AND INTO WEDNESDAY. SHOWERS AND THUNDERSTORMS HAVE
DECREASED ACROSS MOST OF THE FORECAST AREA...THOUGH STILL CONTINUE
ALONG THE CONTDVD. LATEST HRRR AND RAP SHOW PRECIPITATION WANING
ACROSS THE SE MTS...VALLEYS AND I-25 CORRIDOR THROUGH 08Z...THEN
INCREASING AGAIN AS FORCING FROM THE UPPER TROF ACROSS THE DESERT
SOUTHWEST STARTS APPROACHES THE REGION. THESE WILL THEN START TO
SPREAD INTO THE SOUTHERN I-25 CORRIDOR AFTER 12Z...THEN INTO ALL
OF THE SOUTHEAST PLAINS BY WED AFTERNOON AS THE UPPER TROF LIFTS
INTO THE TX/OK PANHANDLES AND SE CO BY 00Z. NICE WAA/OVERRUNNING
PATTERN SETS UP ACROSS THE FAR SOUTHEAST PLAINS...AND ALTHOUGH QPF
LOOKS HEAVIEST TO OUR SOUTH AND EAST OF THE AREA...THE SOUTHEAST
PLAINS SHOULD SEE A BOUT OF MODERATE RAINFALL WEDNESDAY
AFTERNOON...PARTICULARLY TO THE EAST OF LHX. ADJUSTED POPS
SLIGHTLY FOR TIMING. NOT A LOT OF CAPE OR SHEAR TO WORK WITH...SO
MAIN THREAT TOMORROW WILL BE THE POTENTIAL FOR LOCALIZED FLASH
FLOODING ACROSS THE SOUTHEAST PLAINS WITH ANY EMBEDDED CONVECTIVE
ELEMENTS...ESPECIALLY SINCE SOIL IS ALREADY SATURATED AND RIVER IS
RUNNING HIGH. -KT
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 337 PM MDT TUE MAY 12 2015
CURRENTLY...A DEEP UPPER TROUGH OF LOW PRESSURE OVER THE WEST COAST
WAS DRAWING MOISTURE UP ACROSS OLD MEXICO...AZ AND NM INTO THE 4
CORNERS. MID AND HIGH LEVEL MOISTURE WAS STREAMING INTO WESTERN
COLORADO...AND CLOUD COVER WAS ON THE INCREASE ACROSS THE WESTERN
HALF OF THE STATE THIS AFTN. A GOOD AMOUNT OF LTG ACTIVITY WAS
EVIDENT IN NM...BUT AS OF 3 PM NO CONVECTION YET ACROSS THE CWA.
STRONG SOUTHERLY SFC WINDS HAVE HELPED TO WARM TEMPS INTO THE MID
60S TO MID 70S ACROSS MUCH OF THE AREA.
TONIGHT AND TOMORROW...MODELS HAVE BEEN FAIRLY CONSISTENT ON KEEPING
SW FLOW ALOFT ACROSS THE REGION OVER THE NEXT 24 HRS. AN UPPER
DISTURBANCE IN THE LARGE SCALE SW FLOW WILL TRACK ACROSS THE 4
CORNERS REGION AND COLORADO TONIGHT AND TOMORROW...AND WILL BE THE
MAIN DRIVER OF CONVECTION SWEEPING ACROSS THE CWA. THE ENHANCED LTG
ACTIVITY CURRENTLY OCCURRING IN NM IS ASSOCIATED WITH THE BEST
DYNAMICS...AND IT LOOKS AS IF THIS AREA OF BEST FORCING WILL TRACK
ACROSS SOUTHERN NM TONIGHT...THEN UP ACROSS EASTERN NM...THE
PANHANDLES AND EASTERN COLORADO WED AFTN. THEREFORE...FEEL THAT
STEADILY INCREASING CLOUD COVER AND PCPN CHANCES FOR THE HIGHER
ELEVATIONS THIS EVE AND OVERNIGHT LOOKS REASONABLE...BUT THE
BULLSEYE FOR CONVECTION WILL THEN FOCUS ON THE SE QUAD OF THE STATE
BEGINNING AFTER 18Z. THE ENTIRE FORECAST AREA IS OUTLOOKED FOR
GENERAL THUNDER TOMORROW...AND LATEST NAM GUIDANCE INDICATE 600-700
J/KG OF CAPE FOR THE SE CORNER SO DO NOT BELIEVE THE AREA WILL SEE
MUCH BY WAY OF SEVERE WX...BUT THUNDERSTORM ACTIVITY IS PROBABLE. AS
FOR TEMPS...INCREASED CLOUD COVER SHOULD KEEP TEMPS MILD TONIGHT
WITH OVERNIGHT MINS IN THE 40S TO NEAR 50F...AND MAX TEMPS TOMORROW
IN THE 60S. MOORE
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 337 PM MDT TUE MAY 12 2015
.WEDNESDAY NIGHT THROUGH FRIDAY...DISTURBANCE EXITS THE STATE
WEDNESDAY EVENING. KEPT HIGHER POPS OVER THE EASTERN PLAINS CLOSER
TO THE KANSAS BORDER. ANTICIPATE NEARLY ALL THE PRECIPITATION
WILL BE EAST OF COLORADO BY MIDNIGHT. ON THURSDAY...STRONG TROUGH
WILL START LIFTING NORTHEASTWARD FROM SOUTHERN CALIFORNIA INTO
WYOMING. ISOLATED TO SCATTERED CONVECTION WILL DEVELOP DURING THE
AFTERNOON AS A WEAK DISTURBANCE MOVES UP FROM THE SOUTHWEST. WEAK
LEE TROUGH WILL DEVELOP OVER THE PLAINS DURING THE DAY...WITH MUCH
OF THE LOWER LEVEL MOISTURE REMAINING IN KANSAS. WITH LOW CAPE
VALUES...DO NOT ANTICIPATE ANY STRONG STORMS. ON FRIDAY...DRY SLOT
MOVES INTO THE EASTERN HALF OF THE CWA FROM THE SOUTHWEST. MODELS
HAVE TRENDED TO HAVE THE DRY LINE BE FURTHER EAST...MOSTLY OUT OF
COLORADO. IF THIS TREND CONTINUES...THREAT FOR SEVERE CONVECTIVE
WEATHER WILL BE LESS THAN EARLIER ANTICIPATED. THERE WILL BE
ENOUGH MOISTURE AND INSTABILITY FOR STORMS OVER THE MOUNTAINS
DURING THE DAY ON FRIDAY.
.SATURDAY AND SUNDAY...TROUGH WILL CONTINUE MOVING TO THE
NORTHEAST. A DISTURBANCE WILL ROTATE EASTWARD ACROSS THE STATE ON
SATURDAY...WHICH WILL INCREASE PRECIPITATION CHANCES OVER THE
MOUNTAINS. LEE TROUGH WILL BE EAST OF THE COLORADO BORDER ON
SATURDAY...WHICH WILL LIMIT THE AMOUNT OF LOW LEVEL MOISTURE ON
THE PLAINS. ON SUNDAY...TROUGH WILL MOVE WELL EAST OF THE REGION.
DIURNAL CONVECTION WILL MOSTLY BE CONFINED TO THE MOUNTAINS. COLD
FRONT WILL PASS OVER THE PLAINS ON SUNDAY...BUT MOISTURE BEHIND
THE FRONT WILL BE LIMITED.
.MONDAY AND TUESDAY...TROUGH RELOADS OVER CALIFORNIA...WITH A
DISTURBANCE PASSING OVER THE REGION TUESDAY OR WEDNESDAY. WITH
LOW LEVEL UPSLOPE CONTINUING...TUESDAY HAS THE POTENTIAL TO BE A
WET DAY. CURRENTLY...DID NOT GO VERY HIGH WITH THE POPS AS THIS IS
DAY 7. THERE ARE STILL ISSUES WITH THE TIMING AND STRENGTH OF THE
TROUGH. --PGW--
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 337 PM MDT TUE MAY 12 2015
VFR CONDITIONS EXPECTED AT COS...PUB AND ALS THROUGH THE NEXT 24
HOURS. INCREASED CLOUD COVER AND CONVECTION IS EXPECTED ACROSS THE
HIGHER TERRAIN AND WESTERN COLORADO THIS EVENING...WHICH WILL THEN
SPILL EAST ACROSS THE I25 CORRIDOR BY MID-MORNING TOMORROW. BEST
CHANCES OF -TSRA AT TAF SITES THIS EVE REMAINS ALS...WITH -SHRA
POSSIBLE THROUGH THE OVERNIGHT HOURS.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KT
SHORT TERM...MOORE
LONG TERM...PGW
AVIATION...MOORE
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
811 PM MDT TUE MAY 12 2015
.UPDATE...
ISSUED AT 810 PM MDT TUE MAY 12 2015
AIRMASS IS GRADUALLY STABILIZING AS COVERAGE OF SHOWERS AND STORMS
HAS DECREASED TO ISOLATED. THESE WILL BE ENDING ON THE PLAINS IN
THE NEXT HOUR OR TWO...WHILE A FEW SHOWERS WILL LIKELY LINGER OR
REDEVELOP LATER TONIGHT IN THE HIGH COUNTRY WITH DEEPER MOISTURE
PLUME AND WEAK Q-G LIFT AHEAD OF NEXT TROUGH. OVERALL FORECAST IS
ON TRACK WITH ONLY MINOR ADJUSTMENTS FOR LATEST TRENDS.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 256 PM MDT TUE MAY 12 2015
AIRMASS IS BECOMING UNSTABLE ALONG THE FRONT RANGE AND NEAR BY
EASTERN PLAINS WHERE CAPES ARE UP TO 1000 J/KG. SHOWERS AND STORMS
HAVE BEEN SLOW TO FORM OVER THE HIGHER TERRAIN WHERE DEW POINTS
ARE IN THE 20S. THE HRRR AND RAP CONTINUE TO SHOW ISOLATED TO
SCATTERED CONVECTION LATER THIS AFTERNOON. AS THESE STORMS MOVE
OFF THE HIGHER TERRAIN...THEY WILL ENCOUNTER GREATER MOISTURE AND
INSTABILITY. EXPECT THE STORMS TO BE CAPABLE OF PRODUCE BRIEF
HEAVY...GUSTY OUTFLOW WINDS TO 40 MPH AND SMALL HAIL. WILL KEEP
THE ISOLATED TO SCATTERED POPS IN THE FORECAST FOR THE EVENING
HOURS.
A SHORT WAVE TROUGH CURRENTLY OVER BAJA CALIFORNIA WILL LIFT
NORTHEAST ACROSS THE REGION ON WEDNESDAY. EXPECT MOSTLY CLOUDY
SKIES AHEAD OF THIS FOR WEDNESDAY. BEST LIFT AND MOISTURE WILL
REMAIN TO THE SOUTH AND EAST OF THE AREA. HOWEVER SHOULD BE ENOUGH
MOISTURE AND LIFT WITH FOR SCATTERED SHOWERS AND THUNDERSTORMS.
CAPES WILL BE LESS THAN 500 J/KG...SO EXPECT STORMS TO STAY BELOW
SEVERE THRESHOLDS. LOWERED HIGH TEMPERATURES A FEW DEGREES DUE TO
THE CLOUDINESS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 256 PM MDT TUE MAY 12 2015
WEAK QG ASCENT SHOULD STILL BE IMPACTING MUCH OF THE CWA AT 00Z
THURSDAY AND WILL GRADUALLY TRANSITION TO SUBSIDENCE OVERNIGHT AS
UPPER LEVEL RIDGING MOVES IN. THIS WILL ALLOW THURSDAY TO HAVE
LOWER POPS ALTHOUGH PROBABLY NOT COMPLETELY ZERO...ESPECIALLY IN
THE MOUNTAINS.
THE NEXT WAVE AND QG ASCENT BEGINS IN THE MORE SOUTHERLY FLOW ON
FRIDAY WHICH SHOULD ALLOW FOR A BIT MORE SHOWER COVERAGE IN THE
MOUNTAINS DURING THE NORMAL DIURNAL TIMES BUT STILL NOTHING
TREMENDOUS. SHOWER ACTIVITY ON THE PLAINS WILL BE BATTLING A LACK
OF UPSLOPE SO PRECIPITATION THERE WILL BE SPOTTY AT BEST.
THE SYSTEM FOR SATURDAY IS LOOKING A BIT LESS PROMISING THAN
EARLIER. SOME SPREAD IN THE SOLUTIONS OF THE UPPER LOW POSITION BUT
THE MODELS ARE SHOWING SOME QG ASCENT OVER THE CWA ALONG WITH LIGHT
QPF. AGAIN...NOTHING TERRIBLY NOTEWORTHY.
STRONG QG SUBSIDENCE IS FORECAST ON SUNDAY ALONG WITH A PUSH OF LOW
LEVEL HIGH PRESSURE FROM THE NORTH WHICH MAY PUT A SIGNIFICANT
DAMPER ON THE PRECIPITATION THREAT SUNDAY. THE UPPER RIDGE MOVES
EAST OF COLORADO ON MONDAY FOR A SLIGHT INCREASE IN CONVECTIVE
ACTIVITY BY TUESDAY.
ALL IN ALL AT THIS TIME IT APPEARS THAT THERE IS A RATHER LOW RISK
OF HEAVY PRECIPITATION THAT COULD WORSEN THE FLOODING SITUATION.
MOREOVER...TEMPERATURES WILL REMAIN ON THE COOL SIDE WHICH WILL
LESSEN THE MELTING OF THE SNOWPACK.
&&
.AVIATION...(FOR THE TAFS THROUGH 06Z WEDNESDAY EVENING)
ISSUED AT 810 PM MDT TUE MAY 12 2015
EVENING SHOWERS AND STORMS HAVE ENDED FOR THE MOST PART. THERE IS
ONLY A SLIGHT RISK OF AN ISOLATED SHOWER STILL DRIFTING NORTHEAST
INTO THE FRONT RANGE AIRPORTS THIS EVENING. OTHERWISE VFR
CONDITIONS WILL PREVAIL THROUGH WEDNESDAY MORNING. EXPECT MORE
SHOWERS AND STORMS TO DEVELOP BY 19Z-21Z WEDNESDAY AS UPPER LEVEL
DISTURBANCE MOVES IN AND AIRMASS BECOMES MORE UNSTABLE. SHOULD SEE
DECENT COVERAGE AGAIN WITH UPPER LEVEL SUPPORT. THE STORMS WILL
BE CAPABLE OF PRODUCING WIND GUSTS TO 35 KNOTS...BRIEF HEAVY RAIN
AND SMALL HAIL. NORMAL SOUTH/SOUTHWEST WINDS TONIGHT MAY SWITCH
MORE EASTERLY AHEAD OF SHORT WAVE BY 18Z-20Z WEDNESDAY...THEN
BECOME VARIABLE AND GUSTY AT TIMES WITH PASSING SHOWERS/STORMS.
&&
.HYDROLOGY...
ISSUED AT 810 PM MDT TUE MAY 12 2015
THE SOUTH PLATTE RIVER HAS CRESTED OVER CENTRAL AND WESTERN MORGAN
COUNTY. THE CREST IS EXPECTED TO MOVE DOWNSTREAM THROUGH EASTERN
MORGAN...NORTHWEST WASHINGTON...AND SOUTHWESTERN LOGAN COUNTIES
THROUGH THE NEXT 24-36 HOURS...FINALLY CRESTING EASTWARD TO
JULESBURG AND THE NEBRASKA LINE BY FRIDAY AND SATURDAY. FORECAST
CRESTS WERE SLIGHTLY LOWERED THIS MORNING ALONG THE SOUTH PLATTE
RIVER. THE CACHE LA POUDRE NEAR GREELEY WILL REMAIN JUST ABOVE
FLOOD STAGE INTO THIS WEEKEND.
ANOTHER ROUND OF SCATTERED THUNDERSTORMS IS EXPECTED WEDNESDAY
AFTERNOON AND EVENING. BRIEF HEAVY RAIN IS POSSIBLE WITH THE
THUNDERSTORMS. BEST CHANCE FOR HEAVY RAIN WILL BE WEDNESDAY
AFTERNOON WHERE UP TO AN INCH WILL BE POSSIBLE UNDER THE STRONGEST
STORMS. THE MOST WIDESPREAD COVERAGE OF THESE STRONGER STORMS
IS EXPECTED TO BE ON THE EASTERN PLAINS...MAINLY EAST OF THE
PLATTE RIVER FLOOD CREST.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BARJENBRUCH
SHORT TERM...MEIER
LONG TERM...ET
AVIATION...BARJENBRUCH
HYDROLOGY...BARJENBRUCH/MEIER
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1118 AM MDT MON MAY 11 2015
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 425 AM MDT MON MAY 11 2015
DRIER DAY IN STORE FOR THE FORECAST AREA WITH TEMPS REBOUNDING
AFTER A COUPLE OF COOLER DAYS. HRRR AND NAM12 GENERATING A FEW
LATE DAY SHOWERS OVER THE HIGHER PEAKS...OTHERWISE IT WILL BE A
DRY DAY ACROSS THE REGION. QUIET PATTERN CONTINUES TONIGHT WITH
SHORTWAVE RIDGING SLIDING EAST INTO THE PLAINS. THIS ALLOWS FOR A
QUICK RETURN TO SOUTHERLY FLOW WITH ANOTHER SURGE OF MOISTURE
WORKING NORTHWARD BY MIDDAY TUESDAY. PRECIPITABLE WATER VALUES
CLIMB TO OVER A HALF INCH ACROSS THE SOUTHERN MOUNTAINS BY LATE
TUESDAY AFTERNOON...SO POTENTIAL FOR LOCALLY HEAVY RAIN IS NOT OUT
OF THE QUESTION. MODELS ARE IN GOOD AGREEMENT WITH AT LEAST
SCATTERED CONVECTION FIRING OVER THE MOUNTAINS AND SOUTHERN
VALLEYS TUESDAY AFTERNOON AND EVENING AND HAVE RAMPED POPS UPWARD.
TEMPS WILL BE MARCHING TOWARD ABOVE NORMAL READINGS BY TUESDAY
AFTERNOON IN THE STRENGTHENING SOUTHERLY FLOW.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 425 AM MDT MON MAY 11 2015
SHOWERS LINGER TUESDAY EVENING BEFORE A PACIFIC NW WAVE SHUNTS
THE NORTHERLY PROGRESSING MOISTURE BACK TO OUR EAST...WITH GENERAL
DECREASE IN ACTIVITY THROUGH MIDDAY WEDNESDAY. DIURNAL HEATING AND
LINGERING LOW LEVEL MOISTURE SHOULD FIRE A FEW MORE SHOWERS AND
THUNDERSTORMS WEDNESDAY AFTERNOON AND AGAIN THURSDAY. ACTIVITY
PICKS UP IN EARNEST BY FRIDAY AS ANOTHER STRONG LOW PUSHES INTO
THE GREAT BASIN. DEEP SWLY FLOW TAPS MOISTURE OFF THE BAJA AND
LIFTS IT NORTHEAST INTO THE FOUR CORNERS EARLY FRIDAY...SPREADING
NORTH IN INCREASINGLY DIFLUENT PATTERN OVER THE FORECAST AREA.
THIS WILL TRIGGER FAIRLY WIDESPREAD SHOWERS AND THUNDERSTORMS BY
FRIDAY AFTERNOON WITH ACTIVITY LIKELY TO CONTINUE THROUGH THE
WEEKEND AS THE LOW LIFTS NORTHEAST INTO WYOMING. LATEST RUNS ARE A
TAD BIT SLOWER AND DEEPER WITH THE LOW VERSUS EARLIER RUNS...BUT
CONFIDENCE IS FAIRLY HIGH WE WILL BE IN FOR ANOTHER WET END OF THE
WEEK. TEMPS WILL BE RUNNING ON THE PLUS SIDE OF NORMAL THROUGH
THURSDAY...WITH GRADUAL COOLING AS WE MOVE INTO THE WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1115 AM MDT MON MAY 11 2015
NO FLIGHT CONCERNS FOR THE NEXT 24 HOURS OVER TAF SITES. SOME LOW
CLOUDS WILL PERSIST OVER NORTHERN VALLEYS BUT SHOULD LIFT AS THE
DAY PROGRESSES.
&&
.HYDROLOGY...
ISSUED AT 425 AM MDT MON MAY 11 2015
MOST RIVERS IN WESTERN COLORADO REMAIN WELL BELOW BANKFULL STAGES.
HOWEVER...A COMBINATION OF RECENT RAIN FALL AND MELTING MOUNTAIN
SNOW WILL BRING GRADUAL RISES OVER THE NEXT WEEK. A FEW SMALLER
STREAMS AND CREEKS WILL BE RUNNING NEAR BANKFULL.
THE UPPER YAMPA RIVER IS ALREADY AT BANKFULL AND WILL REMAIN NEAR
OR SLIGHTLY ABOVE BANKFULL THROUGH MUCH OF THIS WEEK.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
SHORT TERM...JDC
LONG TERM...JDC
AVIATION...TGR
HYDROLOGY...JDC/AS
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
426 AM MDT MON MAY 11 2015
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 425 AM MDT MON MAY 11 2015
DRIER DAY IN STORE FOR THE FORECAST AREA WITH TEMPS REBOUNDING
AFTER A COUPLE OF COOLER DAYS. HRRR AND NAM12 GENERATING A FEW
LATE DAY SHOWERS OVER THE HIGHER PEAKS...OTHERWISE IT WILL BE A
DRY DAY ACROSS THE REGION. QUIET PATTERN CONTINUES TONIGHT WITH
SHORTWAVE RIDGING SLIDING EAST INTO THE PLAINS. THIS ALLOWS FOR A
QUICK RETURN TO SOUTHERLY FLOW WITH ANOTHER SURGE OF MOISTURE
WORKING NORTHWARD BY MIDDAY TUESDAY. PRECIPITABLE WATER VALUES
CLIMB TO OVER A HALF INCH ACROSS THE SOUTHERN MOUNTAINS BY LATE
TUESDAY AFTERNOON...SO POTENTIAL FOR LOCALLY HEAVY RAIN IS NOT OUT
OF THE QUESTION. MODELS ARE IN GOOD AGREEMENT WITH AT LEAST
SCATTERED CONVECTION FIRING OVER THE MOUNTAINS AND SOUTHERN
VALLEYS TUESDAY AFTERNOON AND EVENING AND HAVE RAMPED POPS UPWARD.
TEMPS WILL BE MARCHING TOWARD ABOVE NORMAL READINGS BY TUESDAY
AFTERNOON IN THE STRENGTHENING SOUTHERLY FLOW.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 425 AM MDT MON MAY 11 2015
SHOWERS LINGER TUESDAY EVENING BEFORE A PACIFIC NW WAVE SHUNTS
THE NORTHERLY PROGRESSING MOISTURE BACK TO OUR EAST...WITH GENERAL
DECREASE IN ACTIVITY THROUGH MIDDAY WEDNESDAY. DIURNAL HEATING AND
LINGERING LOW LEVEL MOISTURE SHOULD FIRE A FEW MORE SHOWERS AND
THUNDERSTORMS WEDNESDAY AFTERNOON AND AGAIN THURSDAY. ACTIVITY
PICKS UP IN EARNEST BY FRIDAY AS ANOTHER STRONG LOW PUSHES INTO
THE GREAT BASIN. DEEP SWLY FLOW TAPS MOISTURE OFF THE BAJA AND
LIFTS IT NORTHEAST INTO THE FOUR CORNERS EARLY FRIDAY...SPREADING
NORTH IN INCREASINGLY DIFLUENT PATTERN OVER THE FORECAST AREA.
THIS WILL TRIGGER FAIRLY WIDESPREAD SHOWERS AND THUNDERSTORMS BY
FRIDAY AFTERNOON WITH ACTIVITY LIKELY TO CONTINUE THROUGH THE
WEEKEND AS THE LOW LIFTS NORTHEAST INTO WYOMING. LATEST RUNS ARE A
TAD BIT SLOWER AND DEEPER WITH THE LOW VERSUS EARLIER RUNS...BUT
CONFIDENCE IS FAIRLY HIGH WE WILL BE IN FOR ANOTHER WET END OF THE
WEEK. TEMPS WILL BE RUNNING ON THE PLUS SIDE OF NORMAL THROUGH
THURSDAY...WITH GRADUAL COOLING AS WE MOVE INTO THE WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 425 AM MDT MON MAY 11 2015
VFR CONDITIONS EXPECTED THROUGH TONIGHT WITH ONLY ISOLATED
MOUNTAIN SHOWERS. NEAR SHOWERS...EXPECTED LOWERED CIGS AND GUSTY
WINDS TO NEAR 35 MPH. PATCHY FOG RESTRICTING VISIBILITY IFR CONDS
WILL ALSO BE POSSIBLE UNTIL 16Z THIS MORNING...MAINLY IN THE
VALLEYS.
&&
.HYDROLOGY...
ISSUED AT 425 AM MDT MON MAY 11 2015
MOST RIVERS IN WESTERN COLORADO REMAIN WELL BELOW BANKFULL STAGES.
HOWEVER...A COMBINATION OF RECENT RAIN FALL AND MELTING MOUNTAIN
SNOW WILL BRING GRADUAL RISES OVER THE NEXT WEEK. A FEW SMALLER
STREAMS AND CREEKS WILL BE RUNNING NEAR BANKFULL.
THE UPPER YAMPA RIVER IS ALREADY AT BANKFULL AND WILL REMAIN NEAR
OR SLIGHTLY ABOVE BANKFULL THROUGH MUCH OF THIS WEEK.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
SHORT TERM...JDC
LONG TERM...JDC
AVIATION...JDC
HYDROLOGY...JDC/AS
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1129 PM MDT SUN MAY 10 2015
.UPDATE...
ISSUED AT 643 PM MDT SUN MAY 10 2015
TRAILING SHORTWAVE AND VORTICITY MAXIMA AXIS MOVING OVER EASTERN
UT EARLY THIS EVENING WILL MOVE ACROSS THE AREA OVERNIGHT. WITH
THE LIFT AHEAD OF THE SHORTWAVE NOT CLEARING THE DIVIDE UNTIL
AFTER 09Z...AND CONSIDERING CURRENT RADAR/SATELLITE TRENDS
SHOWING WHICH SHORT RANGE MODELS SEEM TO HANDLE PRETTY WELL...HAVE
UPDATED THE FORECAST TO BOOST CHANCE OF PRECIPITATION THROUGH 06Z
FOR MUCH OF EASTERN UT AND WESTERN CO...AND THEN HELD ON TO HIGHER
CHANCES OVER THE CENTRAL MOUNTAINS PAST MIDNIGHT. ISOLATED THUNDER
CAN BE EXPECTED THROUGH MID EVENING AND GUSTY NW WINDS WILL BE
COMMON NEAR ANY OF THE SHOWERS. LIGHT ACCUMULATIONS OF SNOW LIKELY
AT THE HIGHER ELEVATIONS...SOME OF WHICH WILL AFFECT PASSES.
&&
.SHORT TERM...(TONIGHT THROUGH MONDAY NIGHT)
ISSUED AT 323 PM MDT SUN MAY 10 2015
NORTH TO NORTHWESTERLY FLOW CONTINUES ON THE BACK SIDE OF THE LOW
PRESSURE SYSTEM THAT BROUGHT ALL THE SNOW AND RAIN YESTERDAY. THE
NAM12/EC/GFS ALL SHOW A SHORTWAVE MOVING OVER THE FORECAST AREA
THIS EVENING BRINGING ANOTHER ROUND OF PRECIP WITH MOUNTAINOUS
TERRAIN SEEING MORE SNOWFALL. HOWEVER...THESE MODELS DID NOT
INITIALIZE WELL THIS MORNING AND ARE CURRENTLY OVERDOING
QPF/PRECIP. MEANWHILE...THE HRRR AND RAP13 APPEARED TO BE DOING
MUCH BETTER WITH NAILING PRECIP AND WILL FOLLOW THESE SOLUTIONS
IN THE SHORT TERM.
FOR THIS AFTERNOON THEN...WITH COLD AIR ADVECTING IN...MINOR
INSTABILITY EXISTS AND WITH CLOUDS BREAKING UP SOME...A FEW
RUMBLES POSSIBLE THIS AFTN MAINLY FOR ERN UT AND SWRN CO. FOR THIS
EVENING AND TONIGHT...THE RAP13 SHOWS ALMOST NO PRECIP WHILE THE
HRRR DOES SHOW THE WAVE MOVING THROUGH BUT PRECIP AMTS ARE LIGHT
AS THE DISTURBANCE QUICKLY MOVES OVERHEAD. PUT ISOLD/SCTD PRECIP
FOR NORTHERN VALLEYS AND ALL HIGHER TERRAIN TONIGHT.
NORTHERLY FLOW WILL ALSO BRING COOLER TEMPERATURES TO THE REGION
WITH NORTHERN VALLEYS AND SOUTHERN VALLEYS SEEING FREEZING OR JUST
BELOW FREEZING TEMPS. THESE TEMPS WILL BOTTOM OUT JUST BEFORE
SUNRISE SO OPTED TO NOT ISSUE ANY FREEZE WARNINGS. HIGH PRESSURE
WILL THEN BUILD IN BRINGING A PLEASANT START TO THE WORK WEEK.
ANOTHER LOW DRIFTING SOUTHWARD ALONG THE PACIFIC NORTHWEST COAST
WILL CAUSE A RIDGE TO BUILD OVER THE REGION. DECENT WARM AIR
ADVECTION (WAA) COMBINED WITH A DRY SOUTHWEST FLOW WILL BRING MORE
QUIESCENT WEATHER TO FORECAST AREA MONDAY. HOWEVER...12Z GFS DID
SUGGEST THERE MAY BE ENOUGH RESIDUAL MOISTURE OVER THE EASTERN
UINTA MOUNTAINS TO FUEL A FEW DIURNAL SHOWERS/THUNDERSTORMS.
DESPITE WARMING...AFTERNOON HIGHS WILL REMAIN SEVERAL DEGREES
BELOW NORMAL.
DRY CONDITIONS PERSIST MONDAY NIGHT THOUGH THE RIDGE AXIS WILL
SHIFT EAST OF THE CONTINENTAL DIVIDE BY 12Z/TUE AS THE NORTHWEST
PACIFIC LOW PRESSURE SYSTEM MOVES ASHORE OVER SOUTHWEST OREGON.
OVERNIGHT LOWS WILL FALL TO NEAR NORMAL LEVELS AS LOSS OF CLOUD
COVER IS BALANCED BY WAA.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 323 PM MDT SUN MAY 10 2015
THE LOW REMAINS NEARLY STATIONARY DURING THE DAY ON TUESDAY AS A
STRONG VORTICITY LOBE MOVES THROUGH ITS BASE. MEANWHILE...
ISENTROPIC FIELDS INDICATED A SURGE OF LOW LEVEL MOISTURE
ORIGINATING FROM THE GULF OF MEXICO WILL MOVE NORTHWARD OVER THE
CONTINENTAL DIVIDE FUELING SCATTERED SHOWERS AND THUNDERSTORMS
DURING THE AFTERNOON. OVER NORTHEAST UTAH...MODELS DIVIDED ON
WHETHER ENOUGH MOISTURE WILL REMAIN OVER THE EASTERN UINTAS TO
GENERATE MOIST CONVECTION DURING THE AFTERNOON. GIVEN MODEL
DIFFERENCES WILL CONTINUE WITH LOW CHANCES OVER THE EASTERN UINTA
MOUNTAINS. AS WAA ADVECTION CONTINUES...AFTERNOON HIGHS ARE
EXPECTED TO CONTINUE TO INCREASE WITH LATEST GUIDANCE INDICATING
HIGHS AROUND 5 DEGREES ABOVE NORMAL.
SHOWERS AND THUNDERSTORMS WILL CONTINUE INTO TUESDAY EVENING AND
MAY PERSIST OVER THE SAN JUAN MOUNTAINS LATE INTO THE NIGHT AS A
SHORTWAVE IN THE SOUTHERN STREAM MOVES ACROSS THE SOUTHWEST.
EXPECT ANOTHER ROUND OF DIURNALLY DRIVEN MOIST CONVECTION
WEDNESDAY AFTERNOON/EVENING WITH SOME ENHANCEMENT ACROSS THE SOUTH
ASSOCIATED WITH THE SHORTWAVE TROUGH MENTIONED PREVIOUSLY. ON
THURSDAY...THE TROUGH ALONG THE PACIFIC NORTHWEST SLIPS SOUTHWARD
ALLOWING MOISTURE TO CONTINUE STREAMING NORTHWARD OVER THE DIVIDE.
AS A RESULT...EXPECT SIMILAR CONDITIONS TO WEDNESDAY WITH STORMS
LARGELY ANCHORED TO THE COLORADO MOUNTAINS. AFTERNOON HIGHS WILL
CONTINUE TO RUN SEVERAL DEGREES ABOVE NORMAL AS WAA IN SOUTHWEST
FLOW PERSISTS.
HOWEVER...THE WARM PERIOD ENDS FRIDAY AS A SLUG OF PACIFIC
MOISTURE DRIVEN ACROSS THE SOUTHWEST BY A VORTICITY LOBE EJECTED
FROM THE LOW CENTERED OVER SAN FRANCISCO COMBINES WITH GULF
MOISTURE ALREADY IN PLACE. DIABATIC COOLING ASSOCIATED WITH
INCREASED CLOUDS AND SHOWERS WILL DRIVE COOLING WITH HIGHS
DROPPING OFF BY ABOUT 10 DEGREES RELATIVE TO THURSDAY/S FORECAST
HIGHS WITH READINGS COMING IN ABOUT 5 DEGREES BELOW NORMAL. MODELS
IN FAIRLY GOOD AGREEMENT FOR THE WEEKEND WITH BOTH THE GFS AND
ECMWF DEPICTING ANOTHER MOIST...COOL...AND UNSETTLED PERIOD AS THE
LOW MOVES FROM THE WEST COAST AND ACROSS THE FORECAST AREA
EVENTUALLY REACHING THE NORTHERN PLAINS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1128 PM MDT SUN MAY 10 2015
BACK EDGE OF UPPER LEVEL SHORTWAVE CROSSING WESTERN COLORADO WILL
PASS EAST OF THE DIVIDE BY 10Z...ENDING SHOWER THREAT FOR
KEGE...KASE AND KTEX. KASE COULD SEE IFR-MVFR CONDITIONS THROUGH
ABOUT 08Z IN LIGHT SNOW. CIGS LIFT AND CLEAR OUT BY DAYBREAK WITH
VFR CONDITIONS THE RULE AT ALL SITES THROUGH THE BALANCE OF THE
TAF PERIOD.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
UPDATE...BEN
SHORT TERM...TGR/NL
LONG TERM...NL
AVIATION...BEN
AREA FORECAST DISCUSSION
NWS TAUNTON MA
808 PM EDT TUE MAY 12 2015
.SYNOPSIS...
A FEW SCATTERED SHOWERS AND STORMS ARE POSSIBLE THIS EVENING...
GIVING WAY TO A COOL AND LESS HUMID NIGHT TONIGHT. LARGE HIGH
PRESSURE WILL BUILD ACROSS THE EASTERN U.S. WITH DRIER WEATHER
THROUGH THE REMAINDER OF THIS WEEK. AN APPROACHING WARM FRONT
COULD BRING SCATTERED SHOWERS THIS WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
808 PM EDT...
CONVECTION FIRED UP QUICKLY ACROSS THE SOUTH SHORE THIS EVENING...
AS TWO MESOSCALE BOUNDARIES COLLIDED. THIS CONVECTION CONTINUED TO
MOVE EAST OVER THE COASTAL WATERS.
LATEST RUNS OF THE HRRR MIGHT BE A LITTLE OVERDONE WITH POPS
BETWEEN NOW AND 2 AM. HOWEVER...IT DOES CONVEY THE IDEA OF
WIDESPREAD LIGHT QPF FOR MOST LOCATIONS...ESPECIALLY NORTH OF
I-90.
MAIN CHANGES TO THE FORECAST THIS EVENING WERE TO BRING THINGS
BACK IN LINE WITH OBSERVED TRENDS.
PREVIOUS DISCUSSION...
WE KNEW IT WAS GOING TO BE RACE BETWEEN DRIER AIR WORKING IT/S WAY
INTO THE COLUMN FROM THE NW AND LEFTOVER INSTABILITY AHEAD OF A
COLD FRONT CURRENTLY JUST NW OF THE BOX CWA. SO FAR...THE DRY AIR
IS WINNING...WE HAVE NOTED LOW LVL DWPTS DROPPING RAPIDLY INTO THE
50S WITH MIXING IN WRN CT/MA. K VALUES ARE ALREADY DROPPING BACK
INTO THE 20S NOW AS WELL...SO OVERALL DRY AIR HAS BEEN LIMITING
COVERAGE OF CONVECTION E OF THE FRONT. ANY SMALL LOW-TOPPED CELLS
THAT HAVE DEVELOPED HAVE QUICKLY DIMINISHED...IN SPITE OF THE
AVAILABLE SHEAR. THERE HAS BEEN CONVECTION...ALBEIT LOW TOPPED
CLOSELY ASSOCIATED WITH THE FRONT ITSELF...WHICH HAS PRODUCED SOME
/ALTHOUGH VERY LITTLE/ IC LIGHTNING. THERE IS A WEAKENING RIDGE
OF HIGHER THETA-E AIR IN ERN MA AND RI...AND THIS MAY BE THE AREA
TO WATCH FOR THE NEXT COUPLE OF HOURS. BUT WITH THE SUN BEGINNING
TO SET AFTER 1800L...SUSPECT IT WILL BE VERY DIFFICULT TO GET
SIGNIFICANT CONVECTION FROM THEREAFTER. WILL CONTINUE TO MONITOR
THE ACTUAL FROPA...BUT WITH THIS OFFSHORE NOT LONG AFTER 00Z /OR
2000L/ WILL LIKELY SEE FAIRLY RAPID IMPROVEMENT AND DISSIPATION OF
ANY REMAINING -SHRA.
OTHERWISE TONIGHT...AFTER SKIES GENERALLY CLEAR...WE FINALLY WORK
IN ENOUGH LOWER DWPT AIR TO RELIEVE THE AREA OF THE FOG/STRATUS
WHICH HAS DEFINED OUR OVERNIGHTS RECENTLY. DWPTS SHOULD FALL BACK
INTO THE LOW 40S BY MORNING BUT A BUILDING PRES GRADIENT AHEAD OF
HIGH PRES TO THE W WILL LIKELY KEEP ENOUGH WESTERLY WINDS TO LIMIT
RADIATIONAL COOLING. THEREFORE...ALTHOUGH MINS WILL BE /AND FEEL/
MUCH COOLER TONIGHT...THEY ARE LIKELY TO STOP IN THE LOW 50S.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
TONIGHT...
DRY HIGH PRES NEARLY 1030HPA WILL BE NOSING IN FROM THE W. GOOD
AFTERNOON MIXING WILL ALLOW BL TO REACH LIKELY ABOVE H85...WHERE
TEMPS WILL BE DROPPING THROUGH THROUGH TO ABOUT +2C BY THE
AFTERNOON. GIVEN THE HIGHER MIXING...AND FACT THAT GREENUP IS
STILL IN ITS RELATIVELY EARLY STAGES...ITS LIKELY HIGHS WILL
EXCEED CURRENT 2M TEMP SUGGESTIONS OF MID LOW-MID 60S.
THEREFORE...HAVE MAINLY UPPER 60S AND LOW 70S FOR HIGHS TOMORROW.
THE BUILDING HIGH PRES ALSO SUGGESTS DECENT ISALLOBARIC COUPLET SO
IT/S LIKELY WINDS WILL BE A FACTOR...MAINLY 10-15 MPH WITH GUSTS
25-30 MPH LIKELY. THIS WILL MAKE FIRE WEATHER THE PRIMARY CONCERN
GIVEN A RELATIVE LACK OF WIDESPREAD RAINFALL FROM TUE CONVECTION.
SEE THE SECTION BELOW FOR THIS.
TOMORROW NIGHT...
HIGH PRES WILL BE CONTINUALLY NOSING IN ALLOWING THE OVERNIGHT
PRES GRADIENT TO SLACKEN SUBSTANTIALLY. THE LOSS OF DIURNAL
HEATING WITH LITTLE MOISTURE THROUGH THE COLUMN SHOULD ALSO LEAD
TO A CLEAR NIGHT. WITH AFTERNOON MIXING ALLOWING DWPTS TO DROP
BACK INTO THE UPPER 20S AND LOW 30S...WE MAY HAVE TO BE ON THE
LOOKOUT FOR LOCALIZED FROST DEVELOPMENT IN TYPICALLY COOLER
VALLEYS. NOT CONFIDENT ENOUGH FOR HEADLINES AT THIS TIME...BUT
EVEN SOME OF THE WARMER GUIDANCE IS SUGGESTING A FEW PLACES
APPROACH THE MID 30S AT 2M.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
HIGHLIGHTS...
* HIGH PRESSURE BRINGS DRY WEATHER THROUGH THE END OF THIS WEEK
* RAIN POSSIBLE LATE FRI INTO THIS WEEKEND
* ABOVE NORMAL TEMPERATURES CONTINUE INTO EARLY NEXT WEEK
12/12Z GUIDANCE REMAINS IN DECENT AGREEMENT THROUGH THIS PORTION OF
THE FORECAST. THE FIRST HALF OF THE FORECAST PERIOD IS RATHER QUIET
WITH HIGH PRESSURE BUILDING OVER SOUTHERN NEW ENGLAND. AS WE MOVE
INTO THIS WEEKEND...AN UPPER LEVEL RIDGE STARTS BUILDING OVER THE
REGION. A LOW PRESSURE MOVES FROM THE GREAT LAKES...THROUGH NEW
ENGLAND EARLY THIS WEEKEND.
THURSDAY THROUGH FRIDAY...HIGH PRESSURE BUILDS INTO SOUTHERN NEW
ENGLAND...PASSING SOUTH OF THE REGION THURSDAY NIGHT AND FRIDAY.
QUIET WEATHER IS EXPECTED THROUGH THIS PERIOD WITH TEMPERATURES
RETURNING TO ABOVE NORMAL.
FRIDAY NIGHT INTO SATURDAY...RAIN SHOWERS DEVELOP AS A WARM FRONT
APPROACHES FROM THE SOUTH. NOT CERTAIN THIS FRONT WILL MOVE
COMPLETELY THROUGH OUR REGION. AS SUCH...HAVE LOW CONFIDENCE ON THE
AMOUNT OF AVAILABLE INSTABILITY FOR THUNDERSTORMS. WILL JUST KEEP A
MENTION OF SHOWERS IN THE FORECAST AT THIS TIME.
SUNDAY INTO TUESDAY...THIS PORTION OF THE FORECAST WILL LARGELY
DEPEND ON THE AMPLIFICATION OF AN UPPER RIDGE OVER THE EASTERN USA.
THERE COULD BE ISOLATED TO SCATTERED SHOWERS...MAINLY DURING THE
PEAK HEATING HOURS. RAINFALL CHANCES ARE GREATER TUESDAY AS A COLD
FRONT APPROACHES FROM THE WEST.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
THROUGH TONIGHT...HIGH CONFIDENCE.
MAINLY VFR WITH THE EXCEPTION BEING NANTUCKET WHERE LINGERING
IFR/LIFR CONDITIONS WILL PERSIST UNTIL LATER THIS EVENING. AFTER
WINDS SHIFT MAINLY W TO NW...EXPECTING VFR CONDITIONS EVERYWHERE.
WILL STILL NEED TO MONITOR FOR ISOLATED SHOWERS/TSRA IN SPOTS
THIS EVENING. FEEL THAT TSRA WILL BE TOO ISOLATED TO INCLUDE IN
THE TAFS.
TOMORROW AND TOMORROW NIGHT...HIGH CONFIDENCE.
MAINLY VFR. W-NW WINDS GUSTING UP TO 25 KT AT TIMES THROUGH THE
DAY...DIMINISHING OVERNIGHT.
KBOS TAF...HIGH CONFIDENCE IN TRENDS.
KBDL TAF...HIGH CONFIDENCE IN TRENDS.
OUTLOOK...THURSDAY THROUGH SUNDAY...
THURSDAY THROUGH FRIDAY...HIGH CONFIDENCE. VFR. SEA BREEZES
LIKELY BOTH THURSDAY AND FRIDAY.
FRIDAY NIGHT AND SATURDAY...MODERATE CONFIDENCE. MAINLY VFR. PERIODS
OF MVFR/IFR IN SCATTERED SHOWERS.
SUNDAY...LOW CONFIDENCE. MAINLY VFR. ISOLATED TO SCATTERED MVFR IN
SHOWERS.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH WEDNESDAY NIGHT/...HIGH CONFIDENCE.
TONIGHT AND TOMORROW...
REMNANT SWELLS FROM ANA CONTINUE TO IMPACT MAINLY THE S...AND SE
WATERS...BUT ARE LIKELY TO SPILL INTO THE E WATERS OVERNIGHT. SEAS
WILL GENERALLY RANGE FROM 5-9 FT BUT BEGIN TO DECLINE EARLY IN THE
MORNING AFTER WINDS SHIFT TO THE W. THESE SEAS WILL CONTINUE TO
DECLINE TOMORROW...BUT SUSPECT NEAR SHORE WINDS MAY APPROACH 25 KT
AT TIMES. THEREFORE...HAVE EXTENDED ALL SMALL CRAFT ADVISORIES
THROUGH TOMORROW. ANY REMAINING FOG SHOULD DISSIPATE FINALLY THIS
EVENING.
TOMORROW NIGHT...
WINDS AND SEAS BOTH DIMINISH TOMORROW NIGHT SUCH THAT ANY
REMAINING SMALL CRAFT ADVISORIES CAN BE DROPPED.
OUTLOOK...THURSDAY THROUGH SUNDAY...
THURSDAY THROUGH FRIDAY...HIGH CONFIDENCE. QUIET BOATING WEATHER
EXPECTED AS HIGH PRESSURE BUILDS OVER SOUTHERN NEW ENGLAND.
FRIDAY NIGHT INTO SUNDAY...LOW CONFIDENCE. WHILE CONDITIONS ARE
CURRENTLY EXPECTED TO REMAIN BELOW SMALL CRAFT CRITERIA...WINDS
AND SEAS WILL BE INCREASING AS A WARM FRONT APPROACHES THE WATERS.
5 FOOT SEAS IN PARTICULAR ARE NOT OUT OF THE QUESTION ACROSS THE
OUTER COASTAL WATERS.
&&
.FIRE WEATHER...
TOMORROW...
CONDITIONS RIPE FOR ELEVATED FIRE WEATHER. ONLY CONTINGENT WILL BE
TO MONITOR RAINFALL ACROSS THE EVENING FROM ANY -SHRA/TSRA THAT
DEVELOP ACROSS THE AREA THIS EVENING. HOWEVER...IN SPITE OF ANY
RAINFALL...IT APPEARS RH VALUES WILL DROP TO THE MID 20 PERCENT
RANGE TOMORROW AFTERNOON WHILE W-NW WINDS OF 10-15 MPH WITH GUSTS
25-30 MPH ARE EXPECTED. ACTUALLY TEMPS WILL NOT BE AS WARM AS THE
PREVIOUS FEW DAYS...MAINLY IN THE UPPER 60S AND LOW 70S BY LATE
AFTERNOON...BUT SUNSHINE IS EXPECTED FOR NEARLY ALL DAY. CURRENTLY
A FIRE WEATHER WATCH IS IN PLACE FOR THESE CONDITIONS...AND IT IS
LIKELY THEY WILL BE UPGRADED TO RED FLAG WARNINGS OVERNIGHT.
THURSDAY AND FRIDAY...DRY WEATHER CONDITIONS WILL CONTINUE WITH
MINIMUM RH VALUES DROPPING INTO THE 20 TO 30 PERCENT RANGE. SINCE
HIGH PRESSURE WILL BE OVERHEAD...WINDS WILL BE LIGHT AND
VARIABLE...ALTHOUGH GUSTS COULD REACH 10-15 MPH.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...FIRE WEATHER WATCH WEDNESDAY AFTERNOON FOR CTZ002>004.
MA...HIGH SURF ADVISORY UNTIL 8 PM EDT THIS EVENING FOR MAZ020-
022>024.
FIRE WEATHER WATCH WEDNESDAY AFTERNOON FOR MAZ002>023-026.
RED FLAG WARNING UNTIL 8 PM EDT THIS EVENING FOR MAZ008>011.
RI...HIGH SURF ADVISORY UNTIL 8 PM EDT THIS EVENING FOR RIZ006>008.
FIRE WEATHER WATCH WEDNESDAY AFTERNOON FOR RIZ001>007.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 PM EDT WEDNESDAY FOR ANZ232>235-
237-254>256.
SMALL CRAFT ADVISORY FROM 8 AM TO 5 PM EDT WEDNESDAY FOR
ANZ230-231-236-251.
SMALL CRAFT ADVISORY UNTIL 2 PM EDT WEDNESDAY FOR ANZ250.
&&
$$
SYNOPSIS...BELK/DOODY
NEAR TERM...BELK/DOODY
SHORT TERM...DOODY
LONG TERM...BELK
AVIATION...BELK/DOODY
MARINE...BELK/DOODY
FIRE WEATHER...STAFF
AREA FORECAST DISCUSSION
NWS NEW YORK NY
203 PM EDT MON MAY 11 2015
.SYNOPSIS...
HIGH PRESSURE WELL OFFSHORE DRIFTS EAST THROUGH TONIGHT AS LOW
PRESSURE PASSES TO THE SOUTH AND EAST LATE TONIGHT. A COLD FRONT
APPROACHES TUESDAY...PASSING EAST TUESDAY NIGHT...FOLLOWED BY HIGH
PRESSURE. A WEAK LOW PRESSURE SYSTEM MAY AFFECT THE REGION OVER
THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SOUTHWESTERLY FLOW AROUND HIGH PRESSURE WELL TO THE EAST HAS
MARITIME TROPICAL AIR ADVECTING ACROSS SEAS SURFACE TEMPS IN THE
LOWER 50S. THUS FOG AND STRATUS PERSIST FOR THE SOUTH SHORE OF
LONG ISLAND. DENSE FOG SOUTH OF MONTAUK HIGHWAY AND ESPECIALLY FOR
OCEAN PARKWAY - SPECIAL WEATHER STATEMENT REMAINS EFFECT. AM
PLANNING ON A DENSE FOG ADVISORY ISSUANCE AT 3:30 PM FOR TONIGHT.
OTHERWISE...BACKDOOR COLD FRONT OVER NORTH EASTERN MA AND REMNANTS
OF ANA NEARING NORFOLK. FRONT HAS STRONG 20-25 KT PUSH BEHIND IT
AND MAY REACH NORTHEASTERN SECTION OF THE FORECAST AREA BEFORE
STALLING OUT.
SHOWERS...FORCED BY SURFACE HEATING OVER MONMOUTH AND OCEAN
COUNTY HEADING NNE AT 25 MPH. EXPECT THESE TO DISSIPATE BEFORE
REACHING SOUTHER QUEENS/BROOKLYN.
COULD STILL SEE A SHOWER...PERHAPS A THUNDERSTORM NORTH AND WEST
OF NYC WHERE WEAK INSTABILITY REMAINS. LI`S GET DOWN TO -2 C AND
A FEW HUNDRED JOULES OF CAPE ARE PRESENT. HAVE LEFT THIS OUT OF
THE FORECAST THOUGH AS RAP AND HRRR HAVE NO GOOD SIGNAL ACTIVITY
AND NARRE-TL HAS VERY LOW PROBABILITIES.
TEMPS WERE ADJUSTED SLIGHTLY...MAINLY IN COASTAL SECTIONS FOR
TRENDS WITH THE ONSHORE FLOW. TEMPERATURES SHOULD BE SIMILAR TO
SUNDAY`S HIGHS. LEANED TOWARD THE MUCH WARMER MAV GUIDANCE AND
RAISED A DEGREE OR SO.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
THE SHORTWAVE ASSOCIATED WITH THE REMNANT LOW OF ANA PASSES TO THE
SOUTH AND EAST FROM 06Z TO 12Z AND MAY BRING SOME SHOWERS AND
ISOLATED THUNDER MAINLY TO THE WATERS SOUTH OF LONG ISLAND...WITH
A CHANCE ACROSS EASTERN LONG ISLAND.
MEANWHILE THE UPPER TROUGH AND COLD FRONT SLOWLY APPROACH TONIGHT.
PRECIPITATION STAYS WEST OF THE AREA UNTIL EARLY TUESDAY MORNING
WHEN THE CHANCE OF SHOWERS INCREASES. FORCING WITH THE FRONT WILL
BE MINIMAL ALONG WITH 400 TO 500 CAPE AND WEAK INSTABILITY. SO
WILL KEEP POPS MINIMAL AT SLIGHT CHANCE TO LOW CHANCE. AGAIN
LEANED TOWARD THE WARMER MAV GUIDANCE FOR LOWS AND HIGHS.
DENSE FOG LIKELY RETURNS TO LONG ISLAND AND COASTAL CT THIS
EVENING...THOUGH WSW FLOW TOWARDS MORNING SHOULD CLEAR THINGS UP
QUICKLY ON TUESDAY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
MODELS IN GENERAL AGREEMENT WITH MEAN NE TROUGHING THROUGH THE
MIDWEEK...GRADUALLY SLIDING OFFSHORE WITH MORE ZONAL UPPER FLOW FOR
LATE WEEK/WEEKEND.
SHORTWAVE ENERGY PIVOTS INTO THE NORTHEAST TUESDAY NIGHT...WITH
SURFACE COLD FRONT MOVING THROUGH TUESDAY EVENING...PUSHING ANY
LINGERING SHRA/TSRA ACTIVITY OFFSHORE.
SHORTWAVE CONTINUES TO DIG THROUGH THE NE ON WEDNESDAY WITH
SECONDARY COLD FRONT SLIDING THROUGH. ASSOCIATED SCT-BKN AFT
INSTABILITY CU LIKELY...WITH AN ISOLATED INSTABILITY SHRA POSSIBLE
TO DRIFT SE OFF THE HIGHER TERRAIN INTO AREAS WELL N&W OF NYC. MOST
NOTICEABLE WILL BE A CHANGE TO A MUCH DRIER AND COOLER AIRMASS IN
THE WAKE OF THE COLD FRONTS...WITH HIGHS ONLY IN THE 60S FOR MOST OF
THE REGION ACCOMPANIED BY A BREEZY NW WIND. WITH THE TUE FRONTAL
SYSTEM NOT LOOKING LIKE A WETTING RAIN PRODUCER...THE GUSTY AND DRY
COND ON WED MAY LEND TO POTENTIAL FIRE WEATHER CONCERNS.
CHILLY CONDITIONS WED NIGHT AS HIGH BUILDS IN FROM WEST. PATCHY
FROST POSSIBLE ACROSS INTERIOR LOWER HUD AND SOUTHERN CT AS WELL AS
PINE BARRENS OF LI IF WINDS DECOUPLE QUICK ENOUGH.
DRY...TRANQUIL...AND GRADUAL MODERATING TREND TO SEASONABLE TEMPS
THU INTO FRI AS HIGH PRESSURE BUILDS IN FROM THE WEST.
MODELS IN GENERAL AGREEMENT WITH SW US SHORTWAVE ENERGY EJECTING
INTO THE CENTRAL PLAINS LATE WEEK...AND THEN ROUNDING SOUTHERN
RIDGING BUT WEAKENING AS IT APPROACHES THE REGION FRI NIGHT/SAT. AT
THE SURFACE...POTENTIAL EXISTS FOR A RESULTANT WEAK SURFACE LOW TO
TRACK ACROSS THE REGION ON SAT. HAVE INCREASED POPS TO LOW CHANCE
FOR FRIDAY NIGHT AND SAT BASED ON INCREASED MODEL AGREEMENT ON THIS
SCENARIO.
EARLY INDICATIONS ARE FOR DRY AND NEAR SEASONABLE TEMPS ON SUNDAY AS
CANADIAN MARITIMES HIGH BUILDS INTO THE REGION FROM THE NE DUE TO AN
AMPLIFYING TROUGH OFF SE CANADA COAST.
&&
.AVIATION /17Z MONDAY THROUGH FRIDAY/...
HIGH PRESSURE DRIFTS FURTHER OFFSHORE THROUGH TONIGHT AS LOW
PRESSURE PASSES SOUTH AND EAST OF THE TERMIMALS.
VFR TO START THE TAF PERIOD. CONDITIONS WILL BEGIN TO DETERIORATE
THIS EVENING AND OVERNIGHT TO IFR AND LIFR IN STRATUS AND FOG.
STRATUS AND FOG WILL FIRST RETURN TO KJFK AND KISP AND THEN
OVERSPREAD ALL OTHER TERMINALS THROUGH MIDNIGHT. CONDITIONS
SHOULD BEGIN TO IMPROVE BEFORE SUNRISE ON TUESDAY.
S WINDS 10-15 KT THIS AFTERNOON. GUSTS UP TO AROUND 20 KT FOR
SOME TERMINALS THIS AFTERNOON. S WINDS DIMINISH TONIGHT AND THEN
VEER TO THE SW LATE TONIGHT. SW WINDS INCREASE 10 TO 15 KT WITH
GUSTS 20 TO 25 KT TUESDAY MORNING.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: BRIEF ISO SHOWER POSSIBLE 18-19Z. IFR/LIFR
CONDS THIS EVE COULD COME IN AN HOUR OR TWO QUICKER THAN
CURRENTLY FORECAST.
KLGA FCSTER COMMENTS: BRIEF ISO SHOWER POSSIBLE 19-20Z. IFR/LIFR
CONDS THIS EVE COULD COME IN AN HOUR OR TWO QUICKER/SLOWER THAN
CURRENTLY FORECAST.
KEWR FCSTER COMMENTS: BRIEF ISO SHOWER POSSIBLE 19-20Z. IFR/LIFR
CONDS THIS EVE COULD COME IN AN HOUR OR TWO QUICKER/SLOWER THAN
CURRENTLY FORECAST.
KTEB FCSTER COMMENTS: BRIEF ISO SHOWER POSSIBLE 19-20Z. IFR/LIFR
CONDS THIS EVE COULD COME IN AN HOUR OR TWO QUICKER/SLOWER THAN
CURRENTLY FORECAST.
KHPN FCSTER COMMENTS: IFR/LIFR CONDS THIS EVE COULD COME IN AN
HOUR OR TWO QUICKER THAN CURRENTLY FORECAST.
KISP FCSTER COMMENTS: BRIEF PERIOD OF IFR 18Z TO 19Z. IFR/LIFR
CONDS THIS EVE COULD COME IN AN HOUR OR TWO QUICKER THAN
CURRENTLY FORECAST.
.OUTLOOK FOR 18Z TUESDAY THROUGH SATURDAY...
.TUE AFTN...VFR. ISO TSTM. SW GUSTS 25KT.
.WEDNESDAY-FRIDAY...VFR. NW GUSTS 25-30KT WED.
.SATURDAY...MAINLY VFR. MVFR POSS IN SHOWERS.
&&
.MARINE...
DENSE FOG PERSISTS FOR THE WATERS SOUTH OF LONG ISLAND AS WARM
HUMID AIR MOVES OVER THE COLD SEA SURFACE. PATCHES OF CLEARING ARE
EXPECTED...BUT OVERALL...THE DENSE FOG REMAINS SIGNIFICANT AND THE
ADVISORY CONTINUES THROUGH TUESDAY MORNING.
OTHERWISE...SOUTHWESTERLY FLOW WILL PERSIST ACROSS THE FORECAST
WATERS TODAY AND TONIGHT AS HIGH PRESSURE OVER THE NORTHERN
ATLANTIC DRIFTS EAST. SEAS WILL BUILD TO SMALL CRAFT LEVELS
TONIGHT AS SWELLS FROM THE REMNANT LOW OF ANA PASSES TO THE SOUTH
AND EAST. IN ADDITION SOME GUSTS MAY APPROACH 25 KT. SMALL CRAFT
SEAS WILL REMAIN INTO TUESDAY ALONG WITH SOME GUSTY WIND TO NEAR
25 KT AS A COLD FRONT APPROACHES.
SCA CONDITIONS LIKELY ON THE OCEAN WATERS TUESDAY NIGHT FROM
RESIDUALS SCA SOUTHERLY SWELLS AND INCREASING OFFSHORE WINDS IN WAKE
OF COLD FRONT. MARGINAL SCA GUSTS ARE POSSIBLE ON ALL WATERS TUE
NIGHT IN WAKE OF COLD FRONT...BUT BETTER CHANCE ON ALL NEARSHORE
WATERS ON WEDNESDAY. SCA SWELLS GRADUALLY SUBSIDE ON THE OCEAN WED
INTO WED NIGHT.
SUB SCA CONDS LIKELY THU AND FRI AS HIGH PRESSURE BUILDS OVER THE
WATERS.
&&
.HYDROLOGY...
NO SIGNIFICANT WIDESPREAD RAINFALL IS EXPECTED THROUGH FRIDAY.
A FEW LOCALLY HEAVIER SHOWERS AND THUNDERSTORMS ARE POSSIBLE
TUESDAY WITH BASIN AVERAGE QPF LESS THAN A QUARTER INCH.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 11 AM EDT TUESDAY FOR ANZ345-350-353-
355.
SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 6 PM EDT
TUESDAY FOR ANZ350-353-355.
&&
$$
SYNOPSIS...MET/TONGUE/NV
NEAR TERM...TONGUE
SHORT TERM...MET/TONGUE
LONG TERM...NV
AVIATION...DS
MARINE...MET/TONGUE/NV
HYDROLOGY...MET/NV
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1050 AM EDT MON MAY 11 2015
.SYNOPSIS...
HIGH PRESSURE WELL OFFSHORE DRIFTS EAST THROUGH TONIGHT AS LOW
PRESSURE PASSES TO THE SOUTH AND EAST LATE TONIGHT. A COLD FRONT
APPROACHES TUESDAY...PASSING EAST TUESDAY NIGHT...FOLLOWED BY HIGH
PRESSURE. A WEAK LOW PRESSURE SYSTEM MAY AFFECT THE REGION OVER
THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SOUTHWESTERLY FLOW AROUND HIGH PRESSURE WELL TO THE EAST HAS
MARITIME TROPICAL AIR ADVECTING ACROSS SEAS SURFACE TEMPS IN THE
LOWER 50S. THUS FOG AND STRATUS PERSIST FOR THE SOUTH SHORE OF
LONG ISLAND. DENSE FOG SOUTH OF MONTAUK HIGHWAY AND ESPECIALLY FOR
OCEAN PARKWAY - SPECIAL WEATHER STATEMENT IN EFFECT.
OTHERWISE...BACKDOOR COLD FRONT OVER NORTH EASTERN MA AND REMNANTS
OF ANA NEARING NORFOLK.
A SHOWER OR THUNDERSTORM IS POSSIBLE NORTH AND WEST OF NYC WHERE
WEAK INSTABILITY WILL FORM. LI`S GET DOWN TO -2 C AND A FEW
HUNDRED JOULES OF CAPE ARE PRESENT. HAVE LEFT THIS OUT OF THE
FORECAST THOUGH AS RAP AND HRRR REMAIN ISOLATED WITH ACTIVITY AND
NARRE-TL HAS VERY LOW PROBABILITIES.
TEMPS WERE ADJUSTED SLIGHTLY...MAINLY IN COASTAL SECTIONS FOR
TRENDS WITH THE ONSHORE FLOW. TEMPERATURES SHOULD BE SIMILAR TO
SUNDAY`S HIGHS. LEANED TOWARD THE MUCH WARMER MAV GUIDANCE AND
RAISED A DEGREE OR SO.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
THE SHORTWAVE ASSOCIATED WITH THE REMNANT LOW OF ANA PASSES TO THE
SOUTH AND EAST FROM 06Z TO 12Z AND MAY BRING SOME SHOWERS AND
ISOLATED THUNDER MAINLY TO THE WATERS SOUTH OF LONG ISLAND...WITH
A CHANCE ACROSS EASTERN LONG ISLAND.
MEANWHILE THE UPPER TROUGH AND COLD FRONT SLOWLY APPROACH TONIGHT
AND PRECIPITATION WILL REMAIN WEST OF THE AREA UNTIL EARLY TUESDAY
MORNING WHEN THE CHANCE OF SHOWERS INCREASES. FORCING WITH THE
FRONT WILL BE MINIMAL ALONG WITH 400 TO 500 CAPE AND WEAK
INSTABILITY. SO WILL KEEP POPS MINIMAL AT SLIGHT CHANCE TO LOW
CHANCE. AGAIN LEANED TOWARD THE WARMER MAV GUIDANCE FOR LOWS AND
HIGHS.
DENSE FOG LIKELY RETURNS TO LONG ISLAND AND COASTAL CT THIS
EVENING...THOUGH WSW FLOW TOWARDS MORNING SHOULD CLEAR THINGS UP
QUICKLY ON TUESDAY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
MODELS IN GENERAL AGREEMENT WITH MEAN NE TROUGHING THROUGH THE
MIDWEEK...GRADUALLY SLIDING OFFSHORE WITH MORE ZONAL UPPER FLOW FOR
LATE WEEK/WEEKEND.
SHORTWAVE ENERGY PIVOTS INTO THE NORTHEAST TUESDAY NIGHT...WITH
SURFACE COLD FRONT MOVING THROUGH TUESDAY EVENING...PUSHING ANY
LINGERING SHRA/TSRA ACTIVITY OFFSHORE.
SHORTWAVE CONTINUES TO DIG THROUGH THE NE ON WEDNESDAY WITH
SECONDARY COLD FRONT SLIDING THROUGH. ASSOCIATED SCT-BKN AFT
INSTABILITY CU LIKELY...WITH AN ISOLATED INSTABILITY SHRA POSSIBLE
TO DRIFT SE OFF THE HIGHER TERRAIN INTO AREAS WELL N&W OF NYC. MOST
NOTICEABLE WILL BE A CHANGE TO A MUCH DRIER AND COOLER AIRMASS IN
THE WAKE OF THE COLD FRONTS...WITH HIGHS ONLY IN THE 60S FOR MOST OF
THE REGION ACCOMPANIED BY A BREEZY NW WIND. WITH THE TUE FRONTAL
SYSTEM NOT LOOKING LIKE A WETTING RAIN PRODUCER...THE GUSTY AND DRY
COND ON WED MAY LEND TO POTENTIAL FIRE WEATHER CONCERNS.
CHILLY CONDITIONS WED NIGHT AS HIGH BUILDS IN FROM WEST. PATCHY
FROST POSSIBLE ACROSS INTERIOR LOWER HUD AND SOUTHERN CT AS WELL AS
PINE BARRENS OF LI IF WINDS DECOUPLE QUICK ENOUGH.
DRY...TRANQUIL...AND GRADUAL MODERATING TREND TO SEASONABLE TEMPS
THU INTO FRI AS HIGH PRESSURE BUILDS IN FROM THE WEST.
MODELS IN GENERAL AGREEMENT WITH SW US SHORTWAVE ENERGY EJECTING
INTO THE CENTRAL PLAINS LATE WEEK...AND THEN ROUNDING SOUTHERN
RIDGING BUT WEAKENING AS IT APPROACHES THE REGION FRI NIGHT/SAT. AT
THE SURFACE...POTENTIAL EXISTS FOR A RESULTANT WEAK SURFACE LOW TO
TRACK ACROSS THE REGION ON SAT. HAVE INCREASED POPS TO LOW CHANCE
FOR FRIDAY NIGHT AND SAT BASED ON INCREASED MODEL AGREEMENT ON THIS
SCENARIO.
EARLY INDICATIONS ARE FOR DRY AND NEAR SEASONABLE TEMPS ON SUNDAY AS
CANADIAN MARITIMES HIGH BUILDS INTO THE REGION FROM THE NE DUE TO AN
AMPLIFYING TROUGH OFF SE CANADA COAST.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
HIGH PRESSURE REMAINS OFFSHORE THROUGH TONIGHT.
LINGERING MVFR CIGS IMPROVE TO VFR LATE THIS MORNING. ONLY
EXCEPTION IS AT KGON AND KISP WHERE IFR HAS HELD ON LONGER. THIS
SHOULD IMPROVE BY EARLY THIS AFTERNOON.
SW TO S WINDS AROUND 5 TO 10 KT THIS MORNING INCREASES TO 10-15
KT THIS AFTERNOON. GUSTS UP TO AROUND 20 KT FOR SOME TERMINALS
THIS AFTERNOON.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: MVFR CIG 015-025 MAY BRIEFLY HOLD ON
THROUGH 16Z. AN OCCASIONAL GUST TO AROUND 20 KT POSSIBLE THIS
AFTERNOON.
KLGA FCSTER COMMENTS: START TIME OF GUSTS TO 20KT MAY BE OFF BY
+/- AN HOUR.
KEWR FCSTER COMMENTS: MVFR CIG 025-030 MAY BRIEFLY HOLD ON
THROUGH 16Z. START TIME OF GUSTS TO 20KT MAY BE OFF BY
+/- AN HOUR.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES
SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: START TIME OF GUSTS TO 20KT MAY BE OFF BY
+/- AN HOUR.
KHPN FCSTER COMMENTS: MVFR CIG 025-030 MAY BRIEFLY HOLD ON
THROUGH 16Z.
KISP FCSTER COMMENTS: IFR CIG 005-009 MAY LINGER UNTIL 16Z.
IMPROVEMENT TO VFR MAY OCCUR SOONER THAN INDICATED IN TAF. AN
OCCASIONAL GUST TO 20 KT POSSIBLE THIS AFTERNOON.
.OUTLOOK FOR 12Z TUESDAY THROUGH FRIDAY...
.TUE...BCMG VFR BY NOON. ISO TSTM. WSW GUSTS 25KT.
.WEDNESDAY-FRIDAY...VFR. NW GUSTS 25KT WED.
&&
.MARINE...
DENSE FOG PERSISTS FOR THE WATERS SOUTH OF LONG ISLAND AS WARM
HUMID AIR MOVES OVER THE COLD SEA SURFACE. PATCHES OF CLEARING ARE
EXPECTED...BUT OVERALL...THE DENSE FOG REMAINS SIGNIFICANT AND THE
ADVISORY CONTINUES THROUGH THE MORNING.
OTHERWISE...SOUTHWESTERLY FLOW WILL PERSIST ACROSS THE FORECAST
WATERS TODAY AND TONIGHT AS HIGH PRESSURE OVER THE NORTHERN
ATLANTIC DRIFTS EAST. SEAS WILL BUILD TO SMALL CRAFT LEVELS
TONIGHT AS SWELLS FROM THE REMNANT LOW OF ANA PASSES TO THE SOUTH
AND EAST. IN ADDITION SOME GUSTS MAY APPROACH 25 KT. SMALL CRAFT
SEAS WILL REMAIN INTO TUESDAY ALONG WITH SOME GUSTY WIND TO NEAR
25 KT AS A COLD FRONT APPROACHES.
SCA CONDITIONS LIKELY ON THE OCEAN WATERS TUESDAY NIGHT FROM
RESIDUALS SCA SOUTHERLY SWELLS AND INCREASING OFFSHORE WINDS IN WAKE
OF COLD FRONT. MARGINAL SCA GUSTS ARE POSSIBLE ON ALL WATERS TUE
NIGHT IN WAKE OF COLD FRONT...BUT BETTER CHANCE ON ALL NEARSHORE
WATERS ON WEDNESDAY. SCA SWELLS GRADUALLY SUBSIDE ON THE OCEAN WED
INTO WED NIGHT.
SUB SCA CONDS LIKELY THU AND FRI AS HIGH PRESSURE BUILDS OVER THE
WATERS.
&&
.HYDROLOGY...
NO SIGNIFICANT WIDESPREAD RAINFALL IS EXPECTED THROUGH FRIDAY.
A FEW LOCALLY HEAVIER SHOWERS AND THUNDERSTORMS ARE POSSIBLE
TUESDAY WITH BASIN AVERAGE QPF LESS THAN A QUARTER INCH.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 11 AM EDT TUESDAY FOR ANZ345-350-353-
355.
SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 6 PM EDT
TUESDAY FOR ANZ350-353-355.
&&
$$
SYNOPSIS...MET/NV
NEAR TERM...MET/TONGUE
SHORT TERM...MET
LONG TERM...NV
AVIATION...JC/DS
MARINE...MET/NV
HYDROLOGY...MET/NV
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
655 PM EDT MON MAY 11 2015
.SYNOPSIS...
THE REMNANTS OF TROPICAL STORM ANA WILL MOVE NORTHEAST AND OFFSHORE
OVERNIGHT. A COLD FRONT WILL MOVE THROUGH OUR AREA TUESDAY NIGHT...
WITH A SECONDARY COLD FRONT FOLLOWING ON WEDNESDAY. HIGH PRESSURE
WILL MOVE INTO OUR REGION FROM THE NORTHWEST ON THURSDAY...AND
PASS OFFSHORE ON FRIDAY. A WARM FRONT IS FORECAST TO APPROACH FROM
THE SOUTHWEST OVER THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
630 PM ESTF: LOWERED POPS FURTHER THROUGH 09Z TO ALMOST NO MENTION
EXCEPT EXTREME SOUTHEAST. ADJUSTED TEMPS SLIGHTLY MORE THIS EVE
BUT NO OVERALL IMPACT ON HUMID WARM MINS.
550 PM ESTF EARLY UPDATE: SLIGHT ADJUSTMENTS EVENING TEMPS TRENDS
AND WITHDREW LIGHTNING FROM THE FCST. APPEARS TO BE STABILIZING AT
22Z. WE MAY HAVE TO BOOST POPS THIS EVENING ALONG THE SNJ COAST
AND DE COASTS BUT NO CERTAINTY ATTM DESPITE THE RADAR APPEARANCE.
BELOW FROM 330 PM.
THE WATER VAPOR IMAGERY SHOWS A PERSISTENT RIDGE ALOFT ACROSS THE
EAST, HOWEVER IT IS GRADUALLY WEAKENING. THE REMNANTS OF TROPICAL
STORM ANA IS OVER EASTERN VIRGINIA THIS AFTERNOON AND IT IS DRIFTING
NORTHEAST. MEANWHILE, A LARGE TROUGH REMAINS ACROSS THE PLAINS.
THE LAPS DATA INDICATES THAT THE SURFACE-BASED INSTABILITY IS
BETWEEN ABOUT 1000-1500 J/KG ACROSS THE AREA. THERE IS NOT A LOT OF
FORCING, HOWEVER IT APPEARS THAT JUST ENOUGH LOW-LEVEL CONVERGENCE
IS RESULTING IN A BAND OF SOME SHOWERS AND ISOLATED THUNDER ACROSS
PORTIONS OF THE AREA. THESE STARTED IN SOUTHERN NEW JERSEY AND THEN
EXPANDED SOME AS THEY LIFTED NORTHWESTWARD. IT APPEARS THAT JUST
BRIEF DOWNPOURS AND SOME LIGHTNING IS OCCURRING, WHICH THE REGION
NEEDS THE RAINFALL. THIS IS EXPECTED TO CONTINUE THROUGH ABOUT EARLY
EVENING GIVEN LINGERING INSTABILITY AND THE PRESENCE OF PVA FROM
WHAT WAS TROPICAL STORM ANA. IT IS POSSIBLE THAT SOME REDEVELOPMENT
OCCURS FROM ABOUT INTERSTATE 95 ON EASTWARD THIS EVENING AS THE
LEFTOVER CENTER OF ANA TRACKS NEARBY. THE RAP AND HRRR HAVE BEEN
HINTING AT THIS POTENTIAL. THEREFORE WE WILL CARRY SOME SLIGHT CHC
TO LOW CHC POPS FOR ISOLATED/SCATTERED ACTIVITY. WE ALSO ARE
CARRYING SLIGHT CHC POPS FOR A TIME OVERNIGHT ACROSS THE NORTHWEST
ZONES AS CONVECTION FROM THE WEST SHOULD BE WEAKENING WITH AN
EASTWARD EXTENT.
THE NEXT ITEM IS LOW CLOUDS AND FOG. THE AIRMASS REMAINS MOIST AND
WITH THE INVERSION STRENGTHENING ONCE AGAIN AS THE BOUNDARY LAYER
COOLS, STRATUS SHOULD DEVELOP. THERE ARE SOME POCKETS OF LOWER
CLOUDS STILL LINGERING THIS AFTERNOON. WHILE SOME FOG IS EXPECTED,
IT MAY NOT BE ALL THAT DENSE GIVEN THE FLOW IS MORE FROM THE SOUTH
AND SOUTHWEST. IN ADDITION, A WEAK COLD FRONT WILL BE APPROACHING
TOWARD DAYBREAK. WE WILL CARRY THE MOST FOG MENTION CLOSEST TO THE
COAST BUT HOLD OFF ON A DENSE FOG ADVISORY GIVEN LESS CONFIDENCE.
LOW TEMPERATURES WERE MOSTLY A NAM/GFS MOS BLEND.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
AN UPPER-LEVEL TROUGH WILL BE MOVING ACROSS THE GREAT LAKES AND INTO
THE NORTHEAST DURING THE COURSE OF TUESDAY. THIS WILL DRIVE SURFACE
LOW PRESSURE WELL TO OUR NORTH, HOWEVER AN ASSOCIATED COLD FRONT
WILL MOVE THROUGH. IT APPEARS THAT AN INITIAL DEW POINT BOUNDARY
MOVES THROUGH DURING THE MORNING TO MIDDAY HOURS WITH A DROP IN THE
DEW POINTS. THE TRUE AIRMASS CHANGE LOOKS TO HOLD OFF UNTIL LATE IN
THE DAY AND BEYOND. THERE MAY NOT BE MUCH LIFT TO SUPPORT
CONVECTION, PLUS THE AIRMASS IS FORECAST TO BE DRYING OUT THROUGH
THE DAY. THEREFORE WE KEPT MUCH OF THE DAY AND THE CWA DRY DESPITE
THE FRONTAL PASSAGE AND INCOMING UPPER-LEVEL TROUGH.
THERE SHOULD BE SOME STRATUS AND FOG EARLY, HOWEVER THE GUIDANCE
GENERALLY IS BRINGING IN ENOUGH DRYING EARLY TO ALLOW FOR THIS TO
QUICKLY DISSIPATE. THE FORECAST SOUNDINGS SHOW THIS DISTINCT DRYING,
AND ALSO THE BOUNDARY LAYER BECOMING WELL MIXED. AS THE PRESSURE
GRADIENT TIGHTENS AND THE FLOW INCREASES SOME, A BREEZY AFTERNOON IS
ANTICIPATED.
AS FOR THE HIGH TEMPERATURES, WE USED A NAM/GFS MOS BLEND THEN
ADJUSTED UPWARD A LITTLE FOR SOME AREAS GIVEN THE DRYING WHICH
SHOULD HELP BOOST TEMPERATURES WELL INTO THE 80S FOR MANY
LOCATIONS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
OVERVIEW...
MID-LEVEL S/WV TROUGH MOVES THRU THE NORTHEAST CONUS ON WED. FLOW
IS THEN MORE ZONAL OUT OF THE W/NW WITH SEVERAL S/WV DISTURBANCES
TRAVERSING IT THROUGH AT LEAST THE FIRST HALF OF THE WEEKEND. FOR
THE LATTER HALF OF THE WEEKEND INTO EARLY NEXT WEEK...RIDGING MAY
TRY TO BUILD ALONG THE EAST COAST. IN GENERAL...FAIR WX EXPECTED
WED THRU FRI WITH HIGH PRESSURE AND TEMPS NEAR SEASONABLE LEVELS.
THEREAFTER...THERE IS CONSIDERABLE UNCERTAINTY WITH REGARD TO THE
EVOLUTION OF THE PATTERN OVER THE NORTHEAST CONUS. GENERAL MODEL
CONSENSUS SLOWS THE NORTHWARD ADVANCE OF A WARM FRONT AS THE MID-
LEVEL FLOW BECOMES PARALLEL TO IT. BOTH THE GFS AND ECMWF DEVELOP
SEVERAL WAVES OF LOW PRESSURE ALONG THIS BOUNDARY...WHILE THE UK
AND CANADIAN SHOW A MORE DIFFUSE BOUNDARY. NEVERTHELESS...CHANCE
FOR CONVECTION INCREASES DURING THIS TIME FRAME AND TEMPERATURES
TREND ABOVE AVERAGE.
DAILIES...
TUE NIGHT...COLD FRONT PROGGED TO MOVE OFFSHORE EARLY WITH ANY
SHRA/TSRA ENDING BY MIDNIGHT. POST-FRONTAL COLUMN DRIES QUICKLY
WITH CLEARING SKIES. COLD AIR ADVECTION WILL LEAD TO STEEP LOW-
LEVEL LAPSE RATES WHICH SHOULD LEAD TO WIND INITIALLY SCT GUSTS
UP TO 25 KNOTS, POSSIBLY BECOMING WIDESPREAD AFTER MIDNIGHT.
WED AND THU...FAIR WEATHER. SOME HIGH CLOUDS POSSIBLE EACH DAY
WITH THE UPPER JET NEARBY...WHILE MODEL SOUNDINGS INDICATE MORE
SCATTERED CU ON WED AS CONVECTIVE TEMPS ARE REACHED ALONG WITH
LOW-LEVEL MOISTURE TRAPPED BELOW SUBSIDENCE INVERSION. NW FLOW
BOTH DAYS...W/THE POTENTIAL FOR GUSTS OF 25 KNOTS ON WED AFTN.
THE GRADIENT SHOULD RELAX ENOUGH ON THU FOR SEA-BREEZES ALONG
THE SHORE BY THURSDAY.
FRI...HIGH PRES MOVES OFFSHORE LEADING TO A SOUTHERLY FLOW. A
WARM FRONT APPROACHES FROM THE WEST ALONG WITH SOME PRECIP...
BUT THE BULK OF THIS SHOULD REMAIN TO OUR WEST ALONG W/DEEP
MOIST AND BEST DYNAMICS. ATTM...CARRIED SLIGHT CHC POPS OVR
THE WESTERN CWA.
SAT THRU MON...FEEL THE UK/CANADIAN SOLUTION MOST REALISTIC
FOR THIS TIME FRAME...WHICH FEATURES A GRADUALLY MOISTENING
COLUMN DUE TO RETURN SOUTHWEST FLOW AROUND HIGH PRES MOVING
OFFSHORE. A DIFFUSE BOUNDARY IN THE VICINITY WOULD PROVIDE A
FOCUS FOR CONVECTION. THIS BOUNDARY MAY BECOME A COLD FRONT
IN THE SUN-MON TIME FRAME AND MOVE THRU THE REGION.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
TONIGHT...MAINLY VFR WITH ISOLATED EVENING SHOWERS, MAINLY NJ.
CEILINGS LOWERING TO MVFR/IFR WITH ANOTHER ROUND OF STRATUS
/LOCAL FOG/ OVERNIGHT...MAINLY I95 EASTWARD. THE TIMING OF THE
STRATUS IS OF LOWER CONFIDENCE, HOWEVER IT SHOULD HAPPEN FAIRLY
QUICKLY DURING THE EVENING ESPECIALLY CLOSER TO THE COAST.
SOUTHERLY WINDS NEAR 5 KNOTS.
LIFR PATCHY DENSE FOG POSSIBLY VCNTY KRDG IN THE 04Z-10Z TIME
FRAME.
GUSTY SOUTH WINDS 15-20 KT AT 22Z BECOME LIGHT WIND ALL NIGHT
AFTER 00Z/12...FIRST FROM THE SOUTH, THEN AFTER 05Z FROM THE
WEST OR SOUTHWEST.
TUESDAY...ANY LOW CLOUDS AND SOME FOG DISSIPATE BY 13Z, THEN VFR
SCT CLOUDS AOA 4000 FT. WEST- SOUTHWEST WINDS INCREASING TO NEAR
15 KNOTS WITH GUSTS UP TO 25 KNOTS.
OUTLOOK...
TUE NIGHT...MVFR POSSIBLE IN SHRA/TSRA MAINLY BEFORE MIDNIGHT.
NW WIND GUSTS NEAR 25 KT BECOMING INCREASINGLY WIDESPREAD DURING
THE NIGHT.
WED THRU FRI...VFR CONDITIONS EXPECTED. NW WIND GUSTS UP TO 25
KNOTS WED AFTN.
SAT...MVFR POSSIBLE IN SHRA/TSRA.
&&
.MARINE...
A SOUTHERLY FLOW WILL BE MAINTAINED THROUGH TUESDAY, WITH A
SOUTHEAST WIND THIS AFTERNOON NEARSHORE AND UP DELAWARE BAY. A SHIFT
MORE FROM THE SOUTHWEST SHOULD OCCUR TUESDAY AS A WEAK FRONT MOVES
THROUGH BY LATE MORNING, THEN A SECONDARY FRONT ARRIVES LATE IN THE
DAY. MEANWHILE, THE REMNANTS OF TROPICAL DEPRESSION ANA WILL SLIDE
NEARBY TONIGHT. THE COMBINATION OF THE SOUTHERLY FLOW AND THE
PASSING SYSTEM SHOULD BUILD THE SEAS TO AROUND 5 FEET TONIGHT AND
TUESDAY ON THE COASTAL WATERS. THE WAVEWATCH GUIDANCE COULD BE A
LITTLE HIGH THOUGH WITH THE SEAS. THERE MAY BE SOME MARINE FOG ONCE
AGAIN TONIGHT GIVEN THE RATHER WARM AND MOIST AIRMASS OVER THE
COLDER WATERS, HOWEVER THE FLOW IS MORE SOUTH-SOUTHWEST SO THIS MAY
RESULT IN THE MAIN FOG AREA TO OUR NORTHEAST. AS A RESULT, WE WILL
CARRY A FOG MENTION BUT HOLD OFF ON A DENSE FOG ADVISORY ATTM. FOR
TUESDAY, THE FLOW INCREASES AND GUSTS TO 25 KNOTS LOOK TO OCCUR
MAINLY NEARSHORE WHERE THE BEST MIXING WILL BE. THEREFORE, WE WILL
MAINTAIN THE SMALL CRAFT ADVISORY FOR THE COASTAL WATERS MAINLY FOR
ELEVATED SEAS TONIGHT AND TUESDAY. WE HELD OFF ON A SMALL CRAFT
ADVISORY FOR DELAWARE BAY UNTIL TUESDAY NIGHT.
OUTLOOK...
TUE NIGHT THRU WED...SCA FOR WINDS AND SEAS IS NOW EXTENDED
THRU 10Z WED. STRONG, POST-FRONTAL COLD AIR ADVECTION REGIME
OVER WARMER SEA SURFACE TEMPERATURES WILL LEAD TO STEEP LOW-
LEVEL LAPSE RATES AND EFFECTIVE MOMENTUM TRANSFER IN SFC-900
HPA LAYER. EXPECT BOTH NW WINDS AND SEAS MEETING SCA LEVELS.
LOW PROBABILITY OF SCT GUSTS 35 KTS IN THE 10 PM TUESDAY TO 2 AM
WEDNESDAY TIME FRAME.
WED NIGHT THRU SAT...SUB-SCA WINDS AND SEAS ANTICIPATED ATTM.
&&
.FIRE WEATHER...
AN ENHANCED THREAT OF WILDFIRE SPREAD IS POSSIBLE TUESDAY AND
WEDNESDAY.
FOR TUESDAY, WEST-SOUTHWEST WINDS ARE EXPECTED TO GUST UP TO 30
MPH ESPECIALLY IN THE AFTERNOON. THE RELATIVE HUMIDITY VALUES ARE
FORECAST TO DROP INTO THE 30S DURING THE AFTERNOON. SOME WETTING
HAS OCCURRED IN SPOTS TODAY /MONDAY/ HOWEVER THE FUELS ARE RATHER
DRY.
FOR WEDNESDAY, A NORTHWEST WIND IS EXPECTED AND GUSTS OF 20 TO 30
MPH ARE ANTICIPATED. RELATIVE HUMIDITY VALUES ARE FORECAST TO DROP
AROUND 30 PERCENT DURING THE AFTERNOON. APPEARS TO DESTINED FOR
SPS AT A MINIMUM FOR WEDNESDAY. THIS IN PART DUE TO LESS THAN 5
PERCENT OF NORMAL MAY PCPN IN THE NE PART OF PA AND NW PART OF NJ
AND 5 TO 25 PCT OF NORMAL ELSEWHERE.
ACTUAL VALUES UNDER ONE QUARTER INCH SEEM TO BE WIDESPREAD SINCE
ABOUT THE 23RD OF APRIL AND TEMPS ARE AVGING 5 TO 8 DEGS ABOVE
NORMAL FOR THE FIRST 10 DAYS OF MAY!
10 HR FUELS ARE ALREADY DRY EVEN IN THE HUMID CONDITIONS AT 640
PM THIS EVENING.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 6 AM EDT
WEDNESDAY FOR ANZ450>453.
SMALL CRAFT ADVISORY UNTIL 6 AM EDT WEDNESDAY FOR ANZ454-455.
SMALL CRAFT ADVISORY FROM 8 PM TUESDAY TO 6 AM EDT WEDNESDAY
FOR ANZ430-431.
&&
$$
SYNOPSIS...FRANCK
NEAR TERM...DRAG/GORSE 654
SHORT TERM...GORSE
LONG TERM...FRANCK
AVIATION...DRAG/FRANCK/GORSE 654
MARINE...DRAG/FRANCK/GORSE/ROBERTSON 654
FIRE WEATHER...654
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
612 PM EDT MON MAY 11 2015
.SYNOPSIS...
THE REMNANTS OF TROPICAL STORM ANA WILL MOVE NORTHEAST AND OFFSHORE
OVERNIGHT. A COLD FRONT WILL MOVE THROUGH OUR AREA TUESDAY NIGHT...
WITH A SECONDARY COLD FRONT FOLLOWING ON WEDNESDAY. HIGH PRESSURE
WILL MOVE INTO OUR REGION FROM THE NORTHWEST ON THURSDAY...AND
PASS OFFSHORE ON FRIDAY. A WARM FRONT IS FORECAST TO APPROACH FROM
THE SOUTHWEST OVER THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
550 PM ESTF EARLY UPDATE: SLIGHT ADJUSTMENTS EVENING TEMPS TRENDS
AND WITHDREW LIGHTNING FROM THE FCST. APPEARS TO BE STABILIZING AT
22Z. WE MAY HAVE TO BOOST POPS THIS EVENING ALONG THE SNJ COAST
AND DE COASTS BUT NO CERTAINTY ATTM DESPITE THE RADAR APPEARANCE.
BELOW FROM 330 PM.
THE WATER VAPOR IMAGERY SHOWS A PERSISTENT RIDGE ALOFT ACROSS THE
EAST, HOWEVER IT IS GRADUALLY WEAKENING. THE REMNANTS OF TROPICAL
STORM ANA IS OVER EASTERN VIRGINIA THIS AFTERNOON AND IT IS DRIFTING
NORTHEAST. MEANWHILE, A LARGE TROUGH REMAINS ACROSS THE PLAINS.
THE LAPS DATA INDICATES THAT THE SURFACE-BASED INSTABILITY IS
BETWEEN ABOUT 1000-1500 J/KG ACROSS THE AREA. THERE IS NOT A LOT OF
FORCING, HOWEVER IT APPEARS THAT JUST ENOUGH LOW-LEVEL CONVERGENCE
IS RESULTING IN A BAND OF SOME SHOWERS AND ISOLATED THUNDER ACROSS
PORTIONS OF THE AREA. THESE STARTED IN SOUTHERN NEW JERSEY AND THEN
EXPANDED SOME AS THEY LIFTED NORTHWESTWARD. IT APPEARS THAT JUST
BRIEF DOWNPOURS AND SOME LIGHTNING IS OCCURRING, WHICH THE REGION
NEEDS THE RAINFALL. THIS IS EXPECTED TO CONTINUE THROUGH ABOUT EARLY
EVENING GIVEN LINGERING INSTABILITY AND THE PRESENCE OF PVA FROM
WHAT WAS TROPICAL STORM ANA. IT IS POSSIBLE THAT SOME REDEVELOPMENT
OCCURS FROM ABOUT INTERSTATE 95 ON EASTWARD THIS EVENING AS THE
LEFTOVER CENTER OF ANA TRACKS NEARBY. THE RAP AND HRRR HAVE BEEN
HINTING AT THIS POTENTIAL. THEREFORE WE WILL CARRY SOME SLIGHT CHC
TO LOW CHC POPS FOR ISOLATED/SCATTERED ACTIVITY. WE ALSO ARE
CARRYING SLIGHT CHC POPS FOR A TIME OVERNIGHT ACROSS THE NORTHWEST
ZONES AS CONVECTION FROM THE WEST SHOULD BE WEAKENING WITH AN
EASTWARD EXTENT.
THE NEXT ITEM IS LOW CLOUDS AND FOG. THE AIRMASS REMAINS MOIST AND
WITH THE INVERSION STRENGTHENING ONCE AGAIN AS THE BOUNDARY LAYER
COOLS, STRATUS SHOULD DEVELOP. THERE ARE SOME POCKETS OF LOWER
CLOUDS STILL LINGERING THIS AFTERNOON. WHILE SOME FOG IS EXPECTED,
IT MAY NOT BE ALL THAT DENSE GIVEN THE FLOW IS MORE FROM THE SOUTH
AND SOUTHWEST. IN ADDITION, A WEAK COLD FRONT WILL BE APPROACHING
TOWARD DAYBREAK. WE WILL CARRY THE MOST FOG MENTION CLOSEST TO THE
COAST BUT HOLD OFF ON A DENSE FOG ADVISORY GIVEN LESS CONFIDENCE.
LOW TEMPERATURES WERE MOSTLY A NAM/GFS MOS BLEND.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
AN UPPER-LEVEL TROUGH WILL BE MOVING ACROSS THE GREAT LAKES AND INTO
THE NORTHEAST DURING THE COURSE OF TUESDAY. THIS WILL DRIVE SURFACE
LOW PRESSURE WELL TO OUR NORTH, HOWEVER AN ASSOCIATED COLD FRONT
WILL MOVE THROUGH. IT APPEARS THAT AN INITIAL DEW POINT BOUNDARY
MOVES THROUGH DURING THE MORNING TO MIDDAY HOURS WITH A DROP IN THE
DEW POINTS. THE TRUE AIRMASS CHANGE LOOKS TO HOLD OFF UNTIL LATE IN
THE DAY AND BEYOND. THERE MAY NOT BE MUCH LIFT TO SUPPORT
CONVECTION, PLUS THE AIRMASS IS FORECAST TO BE DRYING OUT THROUGH
THE DAY. THEREFORE WE KEPT MUCH OF THE DAY AND THE CWA DRY DESPITE
THE FRONTAL PASSAGE AND INCOMING UPPER-LEVEL TROUGH.
THERE SHOULD BE SOME STRATUS AND FOG EARLY, HOWEVER THE GUIDANCE
GENERALLY IS BRINGING IN ENOUGH DRYING EARLY TO ALLOW FOR THIS TO
QUICKLY DISSIPATE. THE FORECAST SOUNDINGS SHOW THIS DISTINCT DRYING,
AND ALSO THE BOUNDARY LAYER BECOMING WELL MIXED. AS THE PRESSURE
GRADIENT TIGHTENS AND THE FLOW INCREASES SOME, A BREEZY AFTERNOON IS
ANTICIPATED.
AS FOR THE HIGH TEMPERATURES, WE USED A NAM/GFS MOS BLEND THEN
ADJUSTED UPWARD A LITTLE FOR SOME AREAS GIVEN THE DRYING WHICH
SHOULD HELP BOOST TEMPERATURES WELL INTO THE 80S FOR MANY
LOCATIONS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
OVERVIEW...
MID-LEVEL S/WV TROUGH MOVES THRU THE NORTHEAST CONUS ON WED. FLOW
IS THEN MORE ZONAL OUT OF THE W/NW WITH SEVERAL S/WV DISTURBANCES
TRAVERSING IT THROUGH AT LEAST THE FIRST HALF OF THE WEEKEND. FOR
THE LATTER HALF OF THE WEEKEND INTO EARLY NEXT WEEK...RIDGING MAY
TRY TO BUILD ALONG THE EAST COAST. IN GENERAL...FAIR WX EXPECTED
WED THRU FRI WITH HIGH PRESSURE AND TEMPS NEAR SEASONABLE LEVELS.
THEREAFTER...THERE IS CONSIDERABLE UNCERTAINTY WITH REGARD TO THE
EVOLUTION OF THE PATTERN OVER THE NORTHEAST CONUS. GENERAL MODEL
CONSENSUS SLOWS THE NORTHWARD ADVANCE OF A WARM FRONT AS THE MID-
LEVEL FLOW BECOMES PARALLEL TO IT. BOTH THE GFS AND ECMWF DEVELOP
SEVERAL WAVES OF LOW PRESSURE ALONG THIS BOUNDARY...WHILE THE UK
AND CANADIAN SHOW A MORE DIFFUSE BOUNDARY. NEVERTHELESS...CHANCE
FOR CONVECTION INCREASES DURING THIS TIME FRAME AND TEMPERATURES
TREND ABOVE AVERAGE.
DAILIES...
TUE NIGHT...COLD FRONT PROGGED TO MOVE OFFSHORE EARLY WITH ANY
SHRA/TSRA ENDING BY MIDNIGHT. POST-FRONTAL COLUMN DRIES QUICKLY
WITH CLEARING SKIES. COLD AIR ADVECTION WILL LEAD TO STEEP LOW-
LEVEL LAPSE RATES WHICH MAY LEAD TO WIND GUSTS UP TO 25 KNOTS
PRIOR TO MIDNIGHT...DIMINISHING THEREAFTER.
WED AND THU...FAIR WEATHER. SOME HIGH CLOUDS POSSIBLE EACH DAY
WITH THE UPPER JET NEARBY...WHILE MODEL SOUNDINGS INDICATE MORE
SCATTERED CU ON WED AS CONVECTIVE TEMPS ARE REACHED ALONG WITH
LOW-LEVEL MOISTURE TRAPPED BELOW SUBSIDENCE INVERSION. NW FLOW
BOTH DAYS...W/THE POTENTIAL FOR GUSTS OF 25 KNOTS ON WED AFTN.
THE GRADIENT SHOULD RELAX ENOUGH ON THU FOR SEA-BREEZES ALONG
THE SHORE BY THURSDAY.
FRI...HIGH PRES MOVES OFFSHORE LEADING TO A SOUTHERLY FLOW. A
WARM FRONT APPROACHES FROM THE WEST ALONG WITH SOME PRECIP...
BUT THE BULK OF THIS SHOULD REMAIN TO OUR WEST ALONG W/DEEP
MOIST AND BEST DYNAMICS. ATTM...CARRIED SLIGHT CHC POPS OVR
THE WESTERN CWA.
SAT THRU MON...FEEL THE UK/CANADIAN SOLUTION MOST REALISTIC
FOR THIS TIME FRAME...WHICH FEATURES A GRADUALLY MOISTENING
COLUMN DUE TO RETURN SOUTHWEST FLOW AROUND HIGH PRES MOVING
OFFSHORE. A DIFFUSE BOUNDARY IN THE VICINITY WOULD PROVIDE A
FOCUS FOR CONVECTION. THIS BOUNDARY MAY BECOME A COLD FRONT
IN THE SUN-MON TIME FRAME AND MOVE THRU THE REGION.
&&
.AVIATION /22Z MONDAY THROUGH SATURDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
TONIGHT...MAINLY VFR WITH ISOLATED EVENING SHOWERS, MAINLY NJ.
CEILINGS LOWERING TO MVFR/IFR WITH ANOTHER ROUND OF STRATUS
/LOCAL FOG/ OVERNIGHT...MAINLY I95 EASTWARD. THE TIMING OF THE
STRATUS IS OF LOWER CONFIDENCE, HOWEVER IT SHOULD HAPPEN FAIRLY
QUICKLY DURING THE EVENING ESPECIALLY CLOSER TO THE COAST.
SOUTHERLY WINDS NEAR 5 KNOTS.
LIFR PATCHY DENSE FOG POSSIBLY VCNTY KRDG IN THE 04Z-10Z TIME
FRAME.
GUSTY SOUTH WINDS 15-20 KT AT 22Z BECOME LIGHT WIND ALL NIGHT
AFTER 00Z/12...FIRST FROM THE SOUTH, THEN AFTER 05Z FROM THE
WEST OR SOUTHWEST.
TUESDAY...ANY LOW CLOUDS AND SOME FOG DISSIPATE BY 13Z, THEN VFR
SCT CLOUDS AOA 4000 FT. WEST- SOUTHWEST WINDS INCREASING TO NEAR
15 KNOTS WITH GUSTS UP TO 25 KNOTS.
OUTLOOK...
TUE NIGHT...MVFR POSSIBLE IN SHRA/TSRA MAINLY BEFORE MIDNIGHT.
NW WIND GUSTS NEAR 25 KT BECOMING INCREASINGLY WIDESPREAD DURING
THE NIGHT.
WED THRU FRI...VFR CONDITIONS EXPECTED. NW WIND GUSTS UP TO 25
KNOTS WED AFTN.
SAT...MVFR POSSIBLE IN SHRA/TSRA.
&&
.MARINE...
A SOUTHERLY FLOW WILL BE MAINTAINED THROUGH TUESDAY, WITH A
SOUTHEAST WIND THIS AFTERNOON NEARSHORE AND UP DELAWARE BAY. A SHIFT
MORE FROM THE SOUTHWEST SHOULD OCCUR TUESDAY AS A WEAK FRONT MOVES
THROUGH BY LATE MORNING, THEN A SECONDARY FRONT ARRIVES LATE IN THE
DAY. MEANWHILE, THE REMNANTS OF TROPICAL DEPRESSION ANA WILL SLIDE
NEARBY TONIGHT. THE COMBINATION OF THE SOUTHERLY FLOW AND THE
PASSING SYSTEM SHOULD BUILD THE SEAS TO AROUND 5 FEET TONIGHT AND
TUESDAY ON THE COASTAL WATERS. THE WAVEWATCH GUIDANCE COULD BE A
LITTLE HIGH THOUGH WITH THE SEAS. THERE MAY BE SOME MARINE FOG ONCE
AGAIN TONIGHT GIVEN THE RATHER WARM AND MOIST AIRMASS OVER THE
COLDER WATERS, HOWEVER THE FLOW IS MORE SOUTH-SOUTHWEST SO THIS MAY
RESULT IN THE MAIN FOG AREA TO OUR NORTHEAST. AS A RESULT, WE WILL
CARRY A FOG MENTION BUT HOLD OFF ON A DENSE FOG ADVISORY ATTM. FOR
TUESDAY, THE FLOW INCREASES AND GUSTS TO 25 KNOTS LOOK TO OCCUR
MAINLY NEARSHORE WHERE THE BEST MIXING WILL BE. THEREFORE, WE WILL
MAINTAIN THE SMALL CRAFT ADVISORY FOR THE COASTAL WATERS MAINLY FOR
ELEVATED SEAS TONIGHT AND TUESDAY. WE HELD OFF ON A SMALL CRAFT
ADVISORY FOR DELAWARE BAY UNTIL TUESDAY NIGHT.
OUTLOOK...
TUE NIGHT THRU WED...SCA FOR WINDS AND SEAS IS NOW EXTENDED
THRU 10Z WED. STRONG, POST-FRONTAL COLD AIR ADVECTION REGIME
OVER WARMER SEA SURFACE TEMPERATURES WILL LEAD TO STEEP LOW-
LEVEL LAPSE RATES AND EFFECTIVE MOMENTUM TRANSFER IN SFC-900
HPA LAYER. EXPECT BOTH NW WINDS AND SEAS MEETING SCA LEVELS.
WED NIGHT THRU SAT...SUB-SCA WINDS AND SEAS ANTICIPATED ATTM.
&&
.FIRE WEATHER...
AN ENHANCED THREAT OF WILDFIRE SPREAD IS POSSIBLE TUESDAY AND
WEDNESDAY.
FOR TUESDAY, WEST-SOUTHWEST WINDS ARE EXPECTED TO GUST UP TO 30
MPH ESPECIALLY IN THE AFTERNOON. THE RELATIVE HUMIDITY VALUES ARE
FORECAST TO DROP INTO THE 30S DURING THE AFTERNOON. SOME WETTING
HAS OCCURRED IN SPOTS TODAY /MONDAY/ HOWEVER THE FUELS ARE RATHER
DRY.
FOR WEDNESDAY, A NORTHWEST WIND IS EXPECTED AND GUSTS OF 20 TO 30
MPH ARE ANTICIPATED. RELATIVE HUMIDITY VALUES ARE FORECAST TO DROP
AROUND 30 PERCENT DURING THE AFTERNOON.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 6 AM EDT
WEDNESDAY FOR ANZ450>453.
SMALL CRAFT ADVISORY UNTIL 6 AM EDT WEDNESDAY FOR ANZ454-455.
SMALL CRAFT ADVISORY FROM 8 PM TUESDAY TO 6 AM EDT WEDNESDAY
FOR ANZ430-431.
&&
$$
SYNOPSIS...FRANCK
NEAR TERM...DRAG/GORSE 613
SHORT TERM...GORSE
LONG TERM...FRANCK
AVIATION...DRAG/FRANCK/GORSE 613
MARINE...DRAG/FRANCK/GORSE/ROBERTSON 613
FIRE WEATHER...
AREA FORECAST DISCUSSION...CORRECTED
NWS MOUNT HOLLY NJ
351 PM EDT MON MAY 11 2015
.SYNOPSIS...
THE REMNANTS OF TROPICAL STORM ANA WILL MOVE NORTHEAST AND OFFSHORE
OVERNIGHT. A COLD FRONT WILL MOVE THROUGH OUR AREA TUESDAY NIGHT...
WITH A SECONDARY COLD FRONT FOLLOWING ON WEDNESDAY. HIGH PRESSURE
WILL MOVE INTO OUR REGION FROM THE NORTHWEST ON THURSDAY...AND
PASS OFFSHORE ON FRIDAY. A WARM FRONT IS FORECAST TO APPROACH FROM
THE SOUTHWEST OVER THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
THE WATER VAPOR IMAGERY SHOWS A PERSISTENT RIDGE ALOFT ACROSS THE
EAST, HOWEVER IT IS GRADUALLY WEAKENING. THE REMNANTS OF TROPICAL
STORM ANA IS OVER EASTERN VIRGINIA THIS AFTERNOON AND IT IS DRIFTING
NORTHEAST. MEANWHILE, A LARGE TROUGH REMAINS ACROSS THE PLAINS.
THE LAPS DATA INDICATES THAT THE SURFACE-BASED INSTABILITY IS
BETWEEN ABOUT 1000-1500 J/KG ACROSS THE AREA. THERE IS NOT A LOT OF
FORCING, HOWEVER IT APPEARS THAT JUST ENOUGH LOW-LEVEL CONVERGENCE
IS RESULTING IN A BAND OF SOME SHOWERS AND ISOLATED THUNDER ACROSS
PORTIONS OF THE AREA. THESE STARTED IN SOUTHERN NEW JERSEY AND THEN
EXPANDED SOME AS THEY LIFTED NORTHWESTWARD. IT APPEARS THAT JUST
BRIEF DOWNPOURS AND SOME LIGHTNING IS OCCURRING, WHICH THE REGION
NEEDS THE RAINFALL. THIS IS EXPECTED TO CONTINUE THROUGH ABOUT EARLY
EVENING GIVEN LINGERING INSTABILITY AND THE PRESENCE OF PVA FROM
WHAT WAS TROPICAL STORM ANA. IT IS POSSIBLE THAT SOME REDEVELOPMENT
OCCURS FROM ABOUT INTERSTATE 95 ON EASTWARD THIS EVENING AS THE
LEFTOVER CENTER OF ANA TRACKS NEARBY. THE RAP AND HRRR HAVE BEEN
HINTING AT THIS POTENTIAL. THEREFORE WE WILL CARRY SOME SLIGHT CHC
TO LOW CHC POPS FOR ISOLATED/SCATTERED ACTIVITY. WE ALSO ARE
CARRYING SLIGHT CHC POPS FOR A TIME OVERNIGHT ACROSS THE NORTHWEST
ZONES AS CONVECTION FROM THE WEST SHOULD BE WEAKENING WITH AN
EASTWARD EXTENT.
THE NEXT ITEM IS LOW CLOUDS AND FOG. THE AIRMASS REMAINS MOIST AND
WITH THE INVERSION STRENGTHENING ONCE AGAIN AS THE BOUNDARY LAYER
COOLS, STRATUS SHOULD DEVELOP. THERE ARE SOME POCKETS OF LOWER
CLOUDS STILL LINGERING THIS AFTERNOON. WHILE SOME FOG IS EXPECTED,
IT MAY NOT BE ALL THAT DENSE GIVEN THE FLOW IS MORE FROM THE SOUTH
AND SOUTHWEST. IN ADDITION, A WEAK COLD FRONT WILL BE APPROACHING
TOWARD DAYBREAK. WE WILL CARRY THE MOST FOG MENTION CLOSEST TO THE
COAST BUT HOLD OFF ON A DENSE FOG ADVISORY GIVEN LESS CONFIDENCE.
LOW TEMPERATURES WERE MOSTLY A NAM/GFS MOS BLEND.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
AN UPPER-LEVEL TROUGH WILL BE MOVING ACROSS THE GREAT LAKES AND INTO
THE NORTHEAST DURING THE COURSE OF TUESDAY. THIS WILL DRIVE SURFACE
LOW PRESSURE WELL TO OUR NORTH, HOWEVER AN ASSOCIATED COLD FRONT
WILL MOVE THROUGH. IT APPEARS THAT AN INITIAL DEW POINT BOUNDARY
MOVES THROUGH DURING THE MORNING TO MIDDAY HOURS WITH A DROP IN THE
DEW POINTS. THE TRUE AIRMASS CHANGE LOOKS TO HOLD OFF UNTIL LATE IN
THE DAY AND BEYOND. THERE MAY NOT BE MUCH LIFT TO SUPPORT
CONVECTION, PLUS THE AIRMASS IS FORECAST TO BE DRYING OUT THROUGH
THE DAY. THEREFORE WE KEPT MUCH OF THE DAY AND THE CWA DRY DESPITE
THE FRONTAL PASSAGE AND INCOMING UPPER-LEVEL TROUGH.
THERE SHOULD BE SOME STRATUS AND FOG EARLY, HOWEVER THE GUIDANCE
GENERALLY IS BRINGING IN ENOUGH DRYING EARLY TO ALLOW FOR THIS TO
QUICKLY DISSIPATE. THE FORECAST SOUNDINGS SHOW THIS DISTINCT DRYING,
AND ALSO THE BOUNDARY LAYER BECOMING WELL MIXED. AS THE PRESSURE
GRADIENT TIGHTENS AND THE FLOW INCREASES SOME, A BREEZY AFTERNOON IS
ANTICIPATED.
AS FOR THE HIGH TEMPERATURES, WE USED A NAM/GFS MOS BLEND THEN
ADJUSTED UPWARD A LITTLE FOR SOME AREAS GIVEN THE DRYING WHICH
SHOULD HELP BOOST TEMPERATURES WELL INTO THE 80S FOR MANY
LOCATIONS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
OVERVIEW...
MID-LEVEL S/WV TROUGH MOVES THRU THE NORTHEAST CONUS ON WED. FLOW
IS THEN MORE ZONAL OUT OF THE W/NW WITH SEVERAL S/WV DISTURBANCES
TRAVERSING IT THROUGH AT LEAST THE FIRST HALF OF THE WEEKEND. FOR
THE LATTER HALF OF THE WEEKEND INTO EARLY NEXT WEEK...RIDGING MAY
TRY TO BUILD ALONG THE EAST COAST. IN GENERAL...FAIR WX EXPECTED
WED THRU FRI WITH HIGH PRESSURE AND TEMPS NEAR SEASONABLE LEVELS.
THEREAFTER...THERE IS CONSIDERABLE UNCERTAINTY WITH REGARD TO THE
EVOLUTION OF THE PATTERN OVER THE NORTHEAST CONUS. GENERAL MODEL
CONSENSUS SLOWS THE NORTHWARD ADVANCE OF A WARM FRONT AS THE MID-
LEVEL FLOW BECOMES PARALLEL TO IT. BOTH THE GFS AND ECMWF DEVELOP
SEVERAL WAVES OF LOW PRESSURE ALONG THIS BOUNDARY...WHILE THE UK
AND CANADIAN SHOW A MORE DIFFUSE BOUNDARY. NEVERTHELESS...CHANCE
FOR CONVECTION INCREASES DURING THIS TIME FRAME AND TEMPERATURES
TREND ABOVE AVERAGE.
DAILIES...
TUE NIGHT...COLD FRONT PROGGED TO MOVE OFFSHORE EARLY WITH ANY
SHRA/TSRA ENDING BY MIDNIGHT. POST-FRONTAL COLUMN DRIES QUICKLY
WITH CLEARING SKIES. COLD AIR ADVECTION WILL LEAD TO STEEP LOW-
LEVEL LAPSE RATES WHICH MAY LEAD TO WIND GUSTS UP TO 25 KNOTS
PRIOR TO MIDNIGHT...DIMINISHING THEREAFTER.
WED AND THU...FAIR WEATHER. SOME HIGH CLOUDS POSSIBLE EACH DAY
WITH THE UPPER JET NEARBY...WHILE MODEL SOUNDINGS INDICATE MORE
SCATTERED CU ON WED AS CONVECTIVE TEMPS ARE REACHED ALONG WITH
LOW-LEVEL MOISTURE TRAPPED BELOW SUBSIDENCE INVERSION. NW FLOW
BOTH DAYS...W/THE POTENTIAL FOR GUSTS OF 25 KNOTS ON WED AFTN.
THE GRADIENT SHOULD RELAX ENOUGH ON THU FOR SEA-BREEZES ALONG
THE SHORE BY THURSDAY.
FRI...HIGH PRES MOVES OFFSHORE LEADING TO A SOUTHERLY FLOW. A
WARM FRONT APPROACHES FROM THE WEST ALONG WITH SOME PRECIP...
BUT THE BULK OF THIS SHOULD REMAIN TO OUR WEST ALONG W/DEEP
MOIST AND BEST DYNAMICS. ATTM...CARRIED SLIGHT CHC POPS OVR
THE WESTERN CWA.
SAT THRU MON...FEEL THE UK/CANADIAN SOLUTION MOST REALISTIC
FOR THIS TIME FRAME...WHICH FEATURES A GRADUALLY MOISTENING
COLUMN DUE TO RETURN SOUTHWEST FLOW AROUND HIGH PRES MOVING
OFFSHORE. A DIFFUSE BOUNDARY IN THE VICINITY WOULD PROVIDE A
FOCUS FOR CONVECTION. THIS BOUNDARY MAY BECOME A COLD FRONT
IN THE SUN-MON TIME FRAME AND MOVE THRU THE REGION.
&&
.AVIATION /20Z MONDAY THROUGH SATURDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
REST OF THIS AFTERNOON...MAINLY VFR CEILINGS. SOUTHERLY WINDS AROUND
10 KNOTS, WITH SOME LOCAL GUSTS UP TO 20 KNOTS AT TIMES. SOME
SHOWERS AND/OR THUNDERSTORMS AROUND.
TONIGHT...MAINLY VFR WITH AN EVENING SHOWER OR THUNDERSTORM AROUND,
THEN CEILINGS LOWERING TO MVFR/IFR WITH ANOTHER ROUND OF STRATUS
/LOCAL FOG/ OVERNIGHT. THE TIMING OF THE STRATUS IS OF LOWER
CONFIDENCE, HOWEVER IT COULD HAPPEN FAIRLY QUICKLY DURING THE
EVENING ESPECIALLY CLOSER TO THE COAST. SOUTHERLY WINDS NEAR 5
KNOTS.
TUESDAY...LOW CLOUDS AND SOME FOG EARLY, THEN VFR. WEST-SOUTHWEST
WINDS INCREASING TO NEAR 15 KNOTS WITH GUSTS UP TO 25 KNOTS.
OUTLOOK...
TUE NIGHT...MVFR POSSIBLE IN SHRA/TSRA MAINLY BEFORE MIDNIGHT.
WED THRU FRI...VFR CONDITIONS EXPECTED. NW WIND GUSTS UP TO 25
KNOTS WED AFTN.
SAT...MVFR POSSIBLE IN SHRA/TSRA.
&&
.MARINE...
A SOUTHERLY FLOW WILL BE MAINTAINED THROUGH TUESDAY, WITH A
SOUTHEAST WIND THIS AFTERNOON NEARSHORE AND UP DELAWARE BAY. A SHIFT
MORE FROM THE SOUTHWEST SHOULD OCCUR TUESDAY AS A WEAK FRONT MOVES
THROUGH BY LATE MORNING, THEN A SECONDARY FRONT ARRIVES LATE IN THE
DAY. MEANWHILE, THE REMNANTS OF TROPICAL DEPRESSION ANA WILL SLIDE
NEARBY TONIGHT. THE COMBINATION OF THE SOUTHERLY FLOW AND THE
PASSING SYSTEM SHOULD BUILD THE SEAS TO AROUND 5 FEET TONIGHT AND
TUESDAY ON THE COASTAL WATERS. THE WAVEWATCH GUIDANCE COULD BE A
LITTLE HIGH THOUGH WITH THE SEAS. THERE MAY BE SOME MARINE FOG ONCE
AGAIN TONIGHT GIVEN THE RATHER WARM AND MOIST AIRMASS OVER THE
COLDER WATERS, HOWEVER THE FLOW IS MORE SOUTH-SOUTHWEST SO THIS MAY
RESULT IN THE MAIN FOG AREA TO OUR NORTHEAST. AS A RESULT, WE WILL
CARRY A FOG MENTION BUT HOLD OFF ON A DENSE FOG ADVISORY ATTM. FOR
TUESDAY, THE FLOW INCREASES AND GUSTS TO 25 KNOTS LOOK TO OCCUR
MAINLY NEARSHORE WHERE THE BEST MIXING WILL BE. THEREFORE, WE WILL
MAINTAIN THE SMALL CRAFT ADVISORY FOR THE COASTAL WATERS MAINLY FOR
ELEVATED SEAS TONIGHT AND TUESDAY. WE HELD OFF ON A SMALL CRAFT
ADVISORY FOR DELAWARE BAY UNTIL TUESDAY NIGHT.
OUTLOOK...
TUE NIGHT THRU WED...SCA FOR WINDS AND SEAS IS NOW EXTENDED
THRU 10Z WED. STRONG, POST-FRONTAL COLD AIR ADVECTION REGIME
OVER WARMER SEA SURFACE TEMPERATURES WILL LEAD TO STEEP LOW-
LEVEL LAPSE RATES AND EFFECTIVE MOMENTUM TRANSFER IN SFC-900
HPA LAYER. EXPECT BOTH NW WINDS AND SEAS MEETING SCA LEVELS.
WED NIGHT THRU SAT...SUB-SCA WINDS AND SEAS ANTICIPATED ATTM.
&&
.FIRE WEATHER...
AN ENHANCED THREAT OF WILDFIRE SPREAD IS POSSIBLE TUESDAY AND
WEDNESDAY.
FOR TUESDAY, WEST-SOUTHWEST WINDS ARE EXPECTED TO GUST UP TO 30
MPH ESPECIALLY IN THE AFTERNOON. THE RELATIVE HUMIDITY VALUES ARE
FORECAST TO DROP INTO THE 30S DURING THE AFTERNOON. SOME WETTING
HAS OCCURRED IN SPOTS TODAY /MONDAY/ HOWEVER THE FUELS ARE RATHER
DRY.
FOR WEDNESDAY, A NORTHWEST WIND IS EXPECTED AND GUSTS OF 20 TO 30
MPH ARE ANTICIPATED. RELATIVE HUMIDITY VALUES ARE FORECAST TO DROP
AROUND 30 PERCENT DURING THE AFTERNOON.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 6 AM EDT
WEDNESDAY FOR ANZ450>453.
SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 6 AM EDT
WEDNESDAY FOR ANZ454-455.
SMALL CRAFT ADVISORY FROM 8 PM TUESDAY TO 6 AM EDT WEDNESDAY
FOR ANZ430-431.
&&
$$
SYNOPSIS...FRANCK
NEAR TERM...GORSE
SHORT TERM...GORSE
LONG TERM...FRANCK
AVIATION...FRANCK/GORSE
MARINE...FRANCK/GORSE
FIRE WEATHER...FRANCK/GORSE
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
400 PM EDT MON MAY 11 2015
.REST OF TODAY...ISOLD SHOWERS HAVE POPPED UP ALONG ATLC SEA BREEZE
AND CONVERGENT BOUNDARIES OVER DUVAL...MARION AND PUTNAM COUNTIES.
SBCAPE ANALYSIS SHOW AROUND 1500J/KG INLAND TO 2500-3000 J/KG TOWARD
THE COAST WHERE DEWPOINTS HAVE RISEN QUICKLY BEHIND THE SEA BREEZE.
TEMPS ARE IN THE LOWER TO MID 90S INLAND AND MID TO UPPER 80S NEAR
THE COAST. ANTICIPATE AN UPTICK IN COVERAGE AND INTENSITY OF
CONVECTION THROUGH THE AFTN...AGAIN MAINLY FOCUSED INTERIOR NE FL
WITH A LESSER CHANCE OVER THE ERN SE GA ZONES. DRY AIR AND
SUBSIDENCE AROUND THE 10000-18000 FT LEVEL WILL HELP LIMIT COVERAGE
OF CONVECTION.
TONIGHT...ISOLD TO SCT SHOWERS AND STORMS EXPECTED TO CONTINUE
INLAND AREAS WHICH WILL GRADUALLY FADE WITH THE LOSS OF HEATING.
NONETHELESS...WITH HIGHER DEWPOINTS AND ANY LINGERING BOUNDARIES
SOME WEAK ISOLD CONVECTION MAY POP UP THROUGH LATE TONIGHT
BUT EXPECTED TO BE SHORT-LIVED. LOW TEMPS GENERALLY 65 TO 70.
VERY PATCHY LIGHT FOG POSSIBLE.
TUESDAY...LOW LEVEL HIGH PRES RIDGE WILL BE LOCATED OVER CENTRAL
FL AGAIN WITH A WEAK COLD FRONT MOVING INTO THE SE CONUS.
PRE-FRONTAL TROUGH OVER SE GA AND W AND E COAST SEA BREEZES WILL
INITIATE AFTN CONVECTION...MAINLY ISOLD IN COVERAGE WITH SCT
SHOWERS AND STORMS POSSIBLE INLAND NE FL WHERE HIGHER DEWPOINTS
ARE EXPECTED. HIGH TEMPS CONTINUE TO BE ABOVE NORMAL IN THE LOWER
TO MID 90S...MID TO UPPER 80S AT THE COAST.
.SHORT TERM (TUESDAY NIGHT THROUGH THURSDAY NIGHT)...
A COLD FRONT MOVING INTO THE SOUTHEASTERN STATES LATE TUESDAY WILL
LOSE SUPPORT ALOFT....AS BROAD RIDGING OVER THE GULF OF MEXICO
EXPANDS EASTWARD OVER THE FL PENINSULA. HOWEVER...THIS BOUNDARY
WILL SERVE AS A FOCUSING MECHANISM...IN CONCERT WITH MESOSCALE
BOUNDARIES...TO SPARK AT LEAST SCATTERED DIURNAL CONVECTION AS THE
FRONT SINKS SOUTHWARD TO THE FL/GA BORDER BY LATE WEDNESDAY AND
STALLS. SCATTERED EARLY EVENING CONVECTION OVER NORTH CENTRAL FL ON
TUESDAY WILL PUSH SLOWLY WESTWARD AND WANE BEFORE MIDNIGHT...WITH
ONLY ISOLATED EARLY EVENING ACTIVITY ELSEWHERE. LOWS WILL REMAIN
ABOVE NORMAL...WITH UPPER 60S INLAND TO LOWER 70S AT THE COAST.
A WEAK SURFACE PRESSURE PATTERN WILL PREVAIL AS THE FRONT MOVES
THROUGH SOUTHEAST GA ON WED...ALLOWING FOR THE ATLANTIC SEA BREEZE
TO MOVE WELL INLAND AND FOCUS MAINLY AFTERNOON AND EVENING
CONVECTION FOR LOCATIONS WEST OF INTERSTATE 95. WE WILL KEEP
SCATTERED POPS IN THE FORECAST FOR NOW...ALTHOUGH AFTERNOON RAIN
CHANCES MAY NEED TO BE INCREASED OVER INLAND NORTHEAST FL IN FUTURE
FORECASTS. A MORE ACTIVE ATLANTIC SEA BREEZE WILL KEEP HIGHS IN THE
80S FOR THE COASTAL COUNTIES ON WED...WITH LOWER 90S EXPECTED
INLAND...EXCEPT A FEW DEGREES COOLER BEHIND THE FRONT NORTH OF
WAYCROSS. EVENING ACTIVITY MAY LINGER OVER NORTH CENTRAL FL...WITH
SLIGHTLY COOLER AND DRIER AIR FILTERING INTO INLAND SOUTHEAST
GA...WHERE LOWS WILL FALL INTO THE 60S. LOWS SOUTH OF THE FRONT WILL
REMAIN IN THE UPPER 60S TO THE LOWER 70S.
SURFACE RIDGING WILL BUILD TO THE NORTH OF OUR REGION ON THURS AS
THE FRONT WASHES OUT OVER NORTHEAST FL...WITH DEEPENING EASTERLY LOW-
LEVEL FLOW FOCUSING ACTIVITY OVER INLAND AREAS...ESPECIALLY ALONG
THE I-75 CORRIDOR BY LATE AFTERNOON. WE WILL MAINTAIN HIGH-END
CHANCE POPS FOR THESE AREAS...BUT RAIN CHANCES WILL NEED TO BE
INCREASED IN FUTURE FORECASTS. AFTERNOON CONVECTION AND EASTERLY
FLOW WILL KEEP HIGHS GENERALLY IN THE 80S...EXCEPT NEAR 90 OVER
NORTH CENTRAL FL. INCREASING LOW-LEVEL MOISTURE WILL KEEP LOWS THURS
NIGHT IN THE UPPER 60S TO LOWER 70S. CONVERGENT LOW LEVEL FLOW OFF
THE ATLANTIC MAY DRIVE A FEW NOCTURNAL SHOWERS ONSHORE INTO THE
COASTAL COUNTIES...GENERALLY AFTER MIDNIGHT.
.LONG TERM (FRIDAY THROUGH MONDAY)... MID-LEVEL RIDGING WILL PREVAIL
OVER THE FL PENINSULA FRI AND SAT DOWNSTREAM OF TROUGHING ALOFT
EMERGING FROM THE ROCKIES AND MOVING NORTHEASTWARD TOWARDS THE GREAT
LAKES STATES. SOUTHEASTERLY LOW LEVEL FLOW WILL MAINTAIN A SCATTERED
TO NUMEROUS MAINLY AFTERNOON AND EVENING CONVECTIVE PATTERN FOR
INLAND LOCATIONS...WITH HIGHEST ACTIVITY EXPECTED ALONG THE I-75
CORRIDOR. A FEW COASTAL SHOWERS MAY AGAIN MOVE ONSHORE FRI NIGHT
INTO EARLY SAT EAST OF I-95. HIGHS WILL REMAIN NEAR TO SLIGHTLY
ABOVE AVERAGE...WITH 80S EXPECTED. ABOVE AVERAGE LOWS IN THE UPPER
60S TO LOWER 70S ARE FORECAST. DEEP-LAYERED RIDGING OVER THE WESTERN
ATLANTIC WILL BEGIN TO WEAKEN TOWARDS SUNDAY...WITH SOME DRIER AIR
ALOFT POSSIBLY MOVING INTO OUR REGION FROM THE EAST.
HOWEVER...INCREASING INSOLATION SHOULD KEEP SEA BREEZES ACTIVE
THROUGH EARLY NEXT WEEK...AND WE WILL MAINTAIN A SCATTERED DIURNAL
CONVECTIVE PATTERN IN THE FORECAST GRIDS. HIGHS WILL CLIMB BACK UP
TOWARDS 90 AT INLAND LOCATIONS...WITH SEA BREEZES KEEPING HIGHS AT
THE COAST IN THE 80S. ABOVE AVERAGE LOW TEMPERATURES WILL PREVAIL.
&&
.AVIATION...PREVAILING VFR. ISOLD CONVECTION WILL NEAR JAX...VQQ
AND GNV THIS AFTN AND EARLY EVENING AS THE ATLC SEA BREEZE PUSHES
INLAND REST OF THE AFTN. INCLUDED VICINITY WORDING FOR THESE TAFS. SE
WINDS 10-15 KT FOR THE COASTAL TAFS REST OF THE AFTN...BECOMING
LIGHT SLY BY LATE EVENING/OVERNIGHT. EXPECT MOST CONVECTION TO
DISSIPATE BY 00Z-03Z TONIGHT. MVFR VSBY POSSIBLE FOR VQQ FROM 07Z-
12Z. ANY ISOLD CONVECTION ON TUESDAY WILL LIKELY HOLD OFF UNTIL
AFTER 18Z.
&&
.MARINE...SLY WINDS AROUND 15 KT...POSSIBLY A BIT HIGHER AT TIMES
TONIGHT THROUGH TUESDAY. LATEST OBSERVED WINDS AND RAP MODEL SUGGEST
NEED FOR SCEC FOR THE NEAR SHORE WATERS THIS EVENING AND WILL
INCLUDE WITH THE AFTN CWF. SEAS MAINLY 2-4 FT...LOCALLY HIGHER AT
TIMES. A WEAK COLD FRONT WILL DROP SOUTHWARD ACROSS AREA WATERS
WEDNESDAY AFTERNOON AND OVERNIGHT WITH WINDS BECOMING ONSHORE AND
INCREASING THROUGH THURSDAY. AN EXERCISE CAUTION WILL LIKELY BE
NEEDED FOR THE OFFSHORE WATERS THURSDAY AND FRIDAY...WITH A CHANCE
OF SCA HEADLINE. THE FRONT WILL BECOME DIFFUSE S OF THE AREA BY
FRIDAY AND SATURDAY AND HIGH PRES N OF THE AREA WILL SHIFT OFFSHORE
INTO THE WRN ATLC VEERING LOCAL WINDS AROUND TO E AND SE.
RIP CURRENTS: MAINLY LOW RISK THROUGH TUESDAY DUE TO MINIMAL
SWELLS.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 66 92 69 89 / 20 20 20 20
SSI 71 86 70 82 / 10 10 20 20
JAX 68 91 70 88 / 10 20 10 30
SGJ 72 87 71 84 / 10 20 10 20
GNV 66 92 68 91 / 20 30 40 40
OCF 68 92 70 91 / 20 30 40 40
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AM...NONE.
&&
$$
SHASHY/NELSON/WALSH
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
321 PM EDT MON MAY 11 2015
.DISCUSSION...
TONIGHT-TUE...AXIS OF LOW LEVEL SURFACE RIDGE ACROSS CENTRAL
FLORIDA WILL HOLD IN PLACE OR NUDGE SLIGHTLY TO THE NORTH. THIS
WILL CONTINUE A RATHER MOIST SOUTHEAST WIND FLOW IN THE LOWER
LEVELS. MID/UPPER LEVELS DO NOT APPEAR PARTICULARLY UNFAVORABLE
FOR CONVECTION AS WINDS ARE LIGHT AND SUBSIDENCE WEAK...BUT NO
IMPULSES WILL BE AFFECTING THE AREA AND THERE IS STILL PLENTY OF
DRY AIR THERE.
THROUGH TONIGHT...STILL EXPECT SCATTERED SHOWERS/STORMS ALONG THE
SEA BREEZE BOUNDARY ACROSS INTERIOR SECTIONS. GREATEST COVERAGE
SHOULD BE ACROSS LAKE COUNTY WHERE THE HRRR IS STILL SHOWING THE
INTERACTION OF THE EAST/WEST COAST SEA BREEZES. OTHERWISE...QUITE
MOIST ONSHORE FLOW MAY BLOW A FEW SHOWERS INTO THE SPACE/TREASURE
COAST OVERNIGHT. THE MOIST/MILD AIR MASS WILL KEEP MIN TEMPS IN
THE UPPER 60S TO LOWER 70S.
FOR TUE...PRECIPITABLE WATER VALUES ARE ONLY FORECAST TO START
OUT THE DAY BETWEEN 1.3 AND 1.5 INCHES AGAIN DUE TO THE LINGERING
DRY AIR ALOFT. THIS WILL CONTINUE TO KEEP POPS LIMITED WITH 20
PERCENT NEAR THE COAST AND 30 INLAND. GREATEST MOISTURE CONVERGENCE
AND CHANCE FOR STRONG STORMS WILL SHIFT TOWARDS THE WEST COAST
LATE IN THE DAY.
MAX TEMPS TYPICAL OF THE EARLY CONVECTIVE SEASON WILL CONTINUE
WITH MID/UPPER 80S ALONG THE COAST AND LOWER 90S INLAND.
WED-THU...WEAK FRONTAL BOUNDARY STALLS NORTH OF THE REGION MID WEEK
AS AN AREA OF HIGH PRESSURE BUILDS TOWARD THE MID ATLANTIC COAST.
THIS WILL INCREASE THE LOW LEVEL ONSHORE FLOW ACROSS THE REGION
THROUGH THE PERIOD. WEATHER PATTERN WILL FAVOR GREATEST CHANCE FOR
SHOWERS AND STORMS ACROSS THE INTERIOR AND WESTERN FL PENINSULA
ALONG THE EAST COAST SEA BREEZE. HIGHS WILL REACH THE LOW 90S ACROSS
THE INTERIOR WED AFT BUT FASTER INLAND MOVEMENT OF THE EAST COAST
SEA BREEZE THU LOOK TO LIMIT MAX TEMPS TO UPPER 80S/NEAR 90.
FRI-SUN...CENTER OF SURFACE HIGH PRESSURE OVER THE MID ATLANTIC
SHIFTS JUST OFFSHORE INTO THE WEEKEND WITH MODELS CONTINUING A
MODERATE EAST TO SOUTHEAST FLOW ACROSS THE REGION. LATE NIGHT AND
MORNING COASTAL SHOWERS WILL GIVE WAY TO ISOLATED TO SCATTERED
AFTERNOON CONVECTION ALONG THE SEA BREEZE AS IT MOVES INLAND AND
ENCOUNTERS MORE UNSTABLE MOIST AIR OVER THE INTERIOR. HIGHS NEAR TO
A COUPLE DEGREES ABOVE CLIMO IN THE MID-UPPER 80S.
&&
.AVIATION...
LARGELY VFR THROUGH THE PERIOD. THERE IS A SMALL CHANCE FOR STORMS
TO AFFECT NORTHERN TERMINALS THROUGH EVENING...PARTICULARLY KLEE.
ONSHORE FLOW MAY BRING A FEW SHOWERS TO THE COAST OVERNIGHT INTO
TUE MORNING...MAINLY KMLB-KSUA. HIGHEST CHANCE FOR AFTERNOON
SHOWERS/STORMS ON TUE WILL AGAIN BE ALONG/WEST OF I-4.
&&
.MARINE...
TONIGHT-TUE...LITTLE CHANGE WITH SURFACE RIDGE AXIS BRINGING A
SOUTHEAST WIND FLOW...WITH MORE OF A SOUTHERLY COMPONENT FAR
NORTH OVERNIGHT/EARLY TUE. SPEEDS SHOULD BE 10-15 KNOTS MOST AREAS
TONIGHT THEN WITH HIGH PRESSURE RIDGE STARTING TO WEAKEN SLIGHTLY
ON TUE...THE SPEEDS SHOULD EASE A FEW KNOTS. A SLIGHT CHANCE FOR
STORMS WILL EXIST TONIGHT INTO TUE MORNING...ESPECIALLY NEAR THE
GULF STREAM.
WED-SAT...HIGH PRESSURE RIDGE BUILDING TOWARD THE MID ATLANTIC WILL
INCREASE ONSHORE FLOW INTO LATE WEEK...UP TO 10-15 KNOTS. SEAS WILL
GRADUALLY RISE...INCREASING UP TO 5 FEET OFFSHORE BY FRI.
MODERATE ONSHORE BREEZE WILL CONTINUE INTO THE WEEKEND WITH SEAS UP
TO 5 TO 6 FEET POSSIBLE OFFSHORE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 70 88 70 88 / 10 20 10 20
MCO 71 93 71 92 / 20 30 10 30
MLB 73 87 73 86 / 10 20 10 20
VRB 71 86 71 86 / 20 20 20 20
LEE 73 93 73 92 / 30 30 20 40
SFB 71 92 71 91 / 20 20 10 30
ORL 72 92 73 91 / 20 20 10 30
FPR 71 87 71 86 / 20 20 20 20
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM...LASCODY
LONG TERM....WEITLICH
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
928 AM EDT MON MAY 11 2015
.DISCUSSION...
TODAY...EARLY MORNING VISIBLE SATELLITE IMAGERY SHOWED ATLANTIC
CLOUDS DENOTING LOW LEVEL RIDGE AXIS VICINITY OF CAPE CANAVERAL.
THIS NORTHWARD SHIFT OF THE HIGH PRESSURE RIDGE WILL BRING GRADIENT
WINDS OUT OF THE SOUTHEAST FOR THE SPACE/TREASURE COAST.
HIGHER MOISTURE WAS NOTED ON THE MORNING SOUNDINGS SO EXPECT A
SLIGHTLY HIGHER COVERAGE OF SHOWERS/STORMS. HOWEVER...A MORE RAPID
INLAND ADVANCE OF THE SEA BREEZE WILL OCCUR...SO THE SPACE/TREASURE
COAST WILL HAVE A BRIEF WINDOW FOR INLAND STORM CHANCES. COASTAL
VOLUSIA WILL HAVE A SLIGHTLY SLOWER INLAND SEA BREEZE MOTION SO
ISOLATED COVERAGE SHOULD OCCUR CLOSER TO THE COAST THERE.
THE HRRR MODEL HAS BEEN SHOWING SCATTERED COVERAGE FROM NEAR THE
KISSIMMEE RIVER IN OKEECHOBEE COUNTY TO ORLANDO...LAKE GEORGE AND
POINTS WESTWARD. THIS IS IN AGREEMENT WITH OUR FORECAST SO DO NOT
PLAN ANY CHANGES.
TEMPS ALOFT ARE RATHER COOL COOL WITH 500MB AROUND -10 DEGREES
CELSIUS AND THERE IS ALSO SOME DRY MID LEVEL AIR. SO WITH DAYTIME
HEATING INTO THE LOWER 90S INLAND...THE STRONGEST BOUNDARY
COLLISIONS WILL BE CAPABLE OF GENERATING ISOLATED STRONG STORMS.
THIS WOULD MOST LIKELY BE WHERE THE EAST/WEST COAST BOUNDARIES
COLLIDE OVER SOUTH LAKE COUNTY OR JUST TO THE WEST OF THERE DURING
THE EVENING.
&&
.AVIATION...PREVIOUS DISCUSSION STILL VALID
THE EAST COAST SEA BREEZE WILL MOVE INLAND FASTER TODAY WITH A
CHANCE FOR STORMS OVER THE NORTH/INTERIOR TERMINALS...KSFB-KMCO-KISM-
KLEE. PLAN TO CONTINUE USING VCTS IN THE TAFS FOR NOW SINCE PROBS
ARE ONLY AROUND 30 PERCENT. THE SEA BREEZE SHOULD BE STRONG THIS
AFTN WITH E/SE FLOW 15-20 KNOTS WITH SOME HIGHER GUSTS MLB-SUA.
&&
.MARINE...
TODAY...LITTLE CHANGE TO PREVIOUS THINKING. WINDS NEAR SURFACE HIGH
PRESSURE RIDGE AXIS VICINITY CANAVERAL-BUOY 41009 WERE
LIGHT/VARIABLE.
SOUTH OF THERE...SOUTHEAST GRADIENT WINDS WILL BE PICKING UP TO 10-
15 KNOTS. NORTHERN WATERS MIGHT NOT SEE THOSE SPEEDS WITH THE RIDGE
AXIS REMAINING NEARBY.
ISOLATED MARINE SHOWERS WILL OCCUR WITH A MORE MOIST REGIME IN
PLACE. A FEW STORMS COULD OCCUR NEAR THE GULF STREAM FROM CANAVERAL
NORTHWARD INTO EARLY AFTERNOON.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
FORECASTS...LASCODY
IMPACT WX...WEITLICH
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
505 AM EDT MON MAY 11 2015
.SYNOPSIS...
09Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS AND AMPLIFIED UPPER
LEVEL PATTERN IN PLACE ACROSS THE CONUS EARLY THIS MORNING...WITH
DEEP TROUGHING ACROSS THE CENTRAL PLAINS/MS VALLEY...AND
DOWNSTREAM RIDGING IN PLACE FORM THE GULF OF MEXICO THROUGH MUCH
OF THE EASTERN CONUS. EMBEDDED WITHIN THIS BROAD SYNOPTIC RIDGE
OVER THE EAST IS THE REMNANTS OF ANA STILL SPINNING OVER EASTERN
NORTH CAROLINA. WHAT IS LEFT OF ANA WILL BE LIFTING TO THE
NORTHEAST AND PASSING SOUTH OF THE NEW ENGLAND COAST OVER THE NEXT
24-36 HOURS. WELL TO OUR WEST ASSOCIATED WITH THE UPPER TROUGH
DIGGING THROUGH THE PLAINS STATES...WE SEE A SIGNIFICANT CLUSTER
OF THUNDERSTORMS STRETCHING FROM EASTERN TEXAS TO
ARKANSAS/MISSOURI...AND IL. FORTUNATELY FOR OUR REGION...WE ARE
PROTECTED BY WEAK RIDING ALOFT...AND THIS WILL HELP FORCE THE
ENERGY WITHIN THE TROUGH RESPONSIBLE FOR THE INCLEMENT WEATHER
TO SHEAR OUT AND PASS WELL TO OUR NORTHWEST / NORTH TODAY AND
TONIGHT.
AT THE SURFACE...ATLANTIC HIGH PRESSURE IS RIDGING BACK TO THE
WEST WITH A RIDGE AXIS ALIGNED ACROSS THE CENTRAL AND NORTHERN FL
PENINSULA/NE GULF OF MEXICO. CONDITIONS ARE DRY AND QUIET OUT
THERE ACROSS THE REGION EARLY THIS MORNING WITH NOTHING ON THE
RADAR AND EVEN VERY FEW CLOUDS IN THE SKY. TEMPERATURES ARE
RUNNING IN THE MIDDLE 60S TO LOWER 70S AT MOST SITES. WARMER
SPOTS IN THE MID/UPPER 70S CAN BE FOUND IN PINELLAS COUNTY AND
ALSO THE ISLANDS OF CHARLOTTE HARBOR.
&&
.SHORT TERM...
THE EARLY PORTION OF THE WORK WEEK WILL FEATURE A SUMMER-LIKE
PATTERN...WITH VERY WARM TEMPERATURES...AND SCATTERED LATE DAY
STORMS.
TODAY AND TONIGHT...
WEAK UPPER RIDGING WILL REMAIN IN PLACE...WHILE THE SUBTROPICAL
SURFACE RIDGE AXIS BECOMES MORE DEFINED ACROSS THE NORTHERN HALF
OF THE FL PENINSULA. THIS RIDGE POSITION WILL FAVOR SYNOPTIC FLOW
/ SEA-BREEZE CONVERGENCE ALONG AND TO THE SOUTH OF THE I-4
CORRIDOR...WHILE A MORE LIGHT/VARIABLE SYNOPTIC FLOW EXISTS
FURTHER NORTH ALONG THE NATURE COAST. WE STILL SEE SOMEWHAT DRY
CONDITIONS ALOFT...BUT NOT OVERWHELMINGLY DRY ENOUGH TO PREVENT
CONVECTION. IT IS STILL EARLY IN THE SEASON...WITH BORDERLINE
WATER TEMPERATURES ACROSS THE EASTERN GULF...SO IT MAY NOT BE
QUITE AS ACTIVE FROM TAMPA BAY SOUTHWARD AS WOULD BE EXPECTED A
MONTH OR TWO FROM NOW WITH THIS PATTERN. HOWEVER...FEEL SCT STORMS
WILL BE A FACTOR LATE IN THE DAY. SCT STORMS SHOULD BEGIN TO FIRE
OVER THE FAR SOUTHERN ZONES AFTER AROUND 19Z...AND AS IS TYPICAL
WITH THIS PATTERN...THEN MIGRATE/DEVELOP NORTHWARD WITH TIME. THE
SEA-BREEZE WILL NOT MOVE MUCH FURTHER INLAND THEN THE I-75
CORRIDOR FROM TAMPA BAY SOUTHWARD...AND SO THIS WOULD BE THE PRIME
FOCUS AREA FOR DEVELOPMENT. FURTHER NORTH...LESS SYNOPTIC
RESISTANCE WILL ALLOW THE SEABREEZE TO MOVE FURTHER
INLAND...MAKING STORMS NEAR THE IMMEDIATE COAST LESS LIKELY THAN
FURTHER SOUTH. HIRES CONVECTION ALLOWING GUIDANCE IS NOT OVERLY
IMPRESSIVE WITH UPDRAFT VELOCITIES THIS AFTERNOON...LIKELY DUE TO
WEAKER LAPSE RATES ALOFT. SO...REALLY NOT ANTICIPATING MUCH IN THE
WAY OF SEVERE STORM POTENTIAL. HOWEVER...SOME SMALL HAIL...GUSTY
WINDS...AND CERTAINLY FREQUENT LIGHTNING WILL BE THREATS.
SINCE MOST OF THE STORMS WILL HOLD OFF UNTIL LATE AFTERNOON OR
EVENING...MOST SPOTS WILL BE ABLE TO GET QUITE WARM / HOT TODAY.
TEMPERATURES AWAY FROM THE BEACHES SHOULD REACH THE LOWER 90S...WITH
EVEN A FEW MIDDLE 90S POSSIBLE SOUTH OF I-4.
SCATTERED STORMS LINGER WELL INTO THE EVENING...AND MAY NOT SEE
THE LAST OF THE STORMS MIGRATE OFF THE COAST UNTIL 02-04Z. THIS
LATE SCENARIO IS A THEME WITH MOST OF THE CONVECTIVE ALLOWING AND
PARAMETERIZED GUIDANCE. THEREFORE...KEPT POPS IN THE FORECAST
ALONG AND INSIDE THE I-75 CORRIDOR A LITTLE LONGER THAN USUAL. BY
MIDNIGHT...THINGS SHOULD GENERALLY BE QUITE ONCE AGAIN WITH A
SEASONABLE AND DRY SECOND HALF OF THE NIGHT / EARLY TUESDAY
MORNING.
TUESDAY...
LITTLE CHANGE IN THE SYNOPTIC SETUP WILL LEAD TO A SIMILAR
FORECAST TO TODAY. OVERALL MOISTURE PROFILES ARE SLIGHTLY MORE
FAVORABLE FOR CONVECTION TO THE SOUTH OF I-4...AND WILL RAISE POPS
5-10% ACROSS THESE AREAS. MUCH OF THE GUIDANCE IS AGGRESSIVE WITH
STORMS COVERAGE AROUND LEE/CHARLOTTE COUNTIES. CAN NOT ARGUE WITH
THIS SCENARIO GIVEN THE FAVORABLE SYNOPTIC FLOW PATTERN AND
BETTER MOISTURE PROFILES. HAVE GONE WITH A 60% LIKELY POP FOR
THESE ZONES...50% FURTHER NORTH TO I-4...AND 30-40% FOR THE TAMPA
BAY AREA AND NATURE COAST ZONES. ONCE AGAIN MUCH OF THIS
CONVECTION WILL HOLD OFF UNTIL VERY LATE AFTERNOON OR EVENING.
THE FORECAST WILL FEATURE LOWER 90S TEMPERATURES AWAY FROM THE
IMMEDIATE COAST.
&&
.LONG TERM (WEDNESDAY THROUGH NEXT SUNDAY)...
RIDGING ALOFT WILL DOMINATE THE GULF OF MEXICO AND FL THROUGH THE
PERIOD. AT THE SURFACE...ON WED HIGH PRESSURE SPRAWLED ACROSS THE
UPPER MID-WEST AND MID-MISSISSIPPI VALLEY WITH A WEAK FRONTAL
BOUNDARY ACROSS THE GULF COASTAL STATES AND UP ALONG THE EASTERN
SEABOARD. THROUGH FRI THE HIGH PRESSURE TREKS EAST...BRIDGING THE
FRONTAL BOUNDARY AS IS SETTLES INTO NORTH FL AND REINFORCING
THE RIDGE ACROSS FL. DURING THE WEEKEND THE HIGH PRESSURE CONTINUES
MOVING EAST ACROSS THE OPEN ATLANTIC WHILE RIDGING BACK WEST...WITH AN
AXIS ACROSS NORTH FL OR SOUTH GA. THE FRONTAL BOUNDARY LIFTS NORTH OF
THE STATE.
FORECAST PHILOSOPHY WILL CONTINUE TO BE BASED ON A MOIST SOUTHEAST OR
EAST LOW LEVEL FLOW...WITH MODEL PWAT VALUES RANGING BETWEEN 1.3 AND
1.9 INCHES. THIS MOISTURE ALONG WITH DAYTIME HEATING AND SEA BREEZE
CIRCULATIONS WILL SUPPORT ISOLATED TO SCATTERED SHOWERS AND STORMS
DURING THE AFTERNOON AND EARLY EVENING HOURS. THE SEA BREEZES WILL TEND
TO KEEP THE HIGHEST COVERAGE INLAND ALTHOUGH THE GRADIENT WILL BRIEFLY
TIGHTEN AT THE END OF THE WORK WEEK...WITH SLIGHTLY MORE ROBUST WINDS
KEEPING THE SE BREEZES CLOSER TO THE COAST. TEMPERATURES WILL RUN ABOVE
NORMAL FOR THE LOWS AND AROUND TO JUST ABOVE FOR THE HIGHS.
&&
.AVIATION...
VFR CONDITIONS ARE EXPECTED TO PREVAIL ACROSS WEST CENTRAL AND
SOUTHWEST FLORIDA THROUGH THE TAF PERIOD...WITH THE EXCEPTION OF
VICINITY THUNDERSTORMS LATE THIS AFTERNOON INTO THE EVENING HOURS.
THUNDERSTORMS ARE NOT EXPECTED TO BE WIDESPREAD...BUT WILL BE
SCATTERED ACROSS THE REGION AFTER 19-20Z. KSRQ/KTBW/KPIE WILL BE
IN THE VICINITY OF THE SEA-BREEZE BOUNDARY THIS AFTERNOON / EARLY
EVENING MAKING WINDS MORE VARIABLE.
&&
.MARINE...
ATLANTIC HIGH PRESSURE WILL RIDGE BACK TO THE WEST ACROSS THE
CENTRAL AND NORTHERN FLORIDA PENINSULA AND NORTHEAST GULF OF
MEXICO THROUGH TUESDAY. WINDS WILL BE DOMINATED THE NEXT COUPLE
OF DAYS BY THE DEVELOPMENT OF AFTERNOON SEA BREEZES NEAR THE
COAST. ALTHOUGH NOT EXPECTED TO BE WIDESPREAD...THE POTENTIAL
EXISTS BOTH TODAY AND TUESDAY FOR A LATE AFTERNOON OR EVENING
THUNDERSTORM NEAR THE COAST. BY THURSDAY INTO FRIDAY...STRONGER
HIGH PRESSURE BUILDS DOWN THE EASTERN SEABOARD...PROVIDING A MORE
GENERAL EASTERLY FLOW ACROSS THE GULF AND HIGHER POTENTIAL FOR
ELEVATED WIND SURGES AT NIGHT.
&&
.FIRE WEATHER...
A RIDGE OF HIGH PRESSURE EXTENDING ACROSS THE FLORIDA PENINSULA
THROUGH TUESDAY. DESPITE VERY WARM TEMPERATURES...ENOUGH LOW
LEVEL MOISTURE IS EXPECTED TO PREVENT CRITICAL LEVELS OF RELATIVE
HUMIDITY FROM BEING REACHED. THEREFORE NO RED FLAG CONDITIONS ARE
IN THE FORECAST. SCATTERED LATE AFTERNOON AND EVENING
THUNDERSTORMS CAN BE EXPECTED BOTH TODAY AND TUESDAY. THE MAJORITY
OF THESE LATE DAY STORMS SHOULD DEVELOP GENERALLY ALONG THE I-75
CORRIDOR...ALTHOUGH ALL ZONES WILL RUN THE RISK OF A BRIEF
DOWNPOUR
FOG IMPACT...NO SIGNIFICANT FOG IS EXPECTED THROUGH THE
TUESDAY. AREAS OF FOG ARE POSSIBLE EARLY WEDNESDAY MORNING...
ESPECIALLY TO THE NORTH OF THE I-4 CORRIDOR.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 91 73 90 74 / 40 40 40 30
FMY 92 71 91 72 / 50 30 60 30
GIF 93 72 92 72 / 40 30 40 20
SRQ 87 71 86 72 / 40 40 50 30
BKV 92 68 90 68 / 40 40 30 30
SPG 90 75 89 76 / 30 40 30 30
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SHORT TERM/AVIATION/MARINE/FIRE WEATHER...14/MROCZKA
LONG TERM...09/RUDE
DECISION SUPPORT...09/RUDE
AREA FORECAST DISCUSSION
NWS LINCOLN IL
327 AM CDT MON MAY 11 2015
.SHORT TERM...(TODAY)
ISSUED AT 327 AM CDT MON MAY 11 2015
07Z/2AM SURFACE ANALYSIS SHOWS 1004MB LOW OVER EASTERN SOUTH
DAKOTA...WITH FRONTAL BOUNDARY ARCING SOUTHEASTWARD THROUGH IOWA AND
MISSOURI INTO EASTERN OKLAHOMA. WHILE MUCH OF THE KILX CWA IS
CURRENTLY DRY...WIDESPREAD CONVECTION ASSOCIATED WITH A 40-45KT
850MB JET STREAK AHEAD OF THE FRONT IS OCCURRING UPSTREAM FROM
EASTERN TEXAS TO NEAR SAINT LOUIS. RADAR TRENDS SUGGEST THIS PRECIP
WILL CONTINUE TO LIFT NORTHWARD INTO CENTRAL ILLINOIS OVER THE NEXT
FEW HOURS...YIELDING A WET START TO THE DAY. COLDEST CLOUD TOPS AND
THUS THE STRONGEST CONVECTION ARE WELL TO THE SOUTH...SO AM NOT
ANTICIPATING ANY SEVERE WEATHER AS THE SHOWERS/STORMS ARRIVE THIS
MORNING. COLD FRONT WILL PUSH EASTWARD ACROSS THE MISSISSIPPI RIVER
BY MID TO LATE MORNING...THEN INTO INDIANA DURING THE AFTERNOON. AS
A RESULT...EXPECT RAIN CHANCES TO GRADUALLY TAPER OFF FROM WEST TO
EAST ACROSS THE AREA TODAY. WILL CARRY CATEGORICAL POPS ACROSS THE
BOARD THIS MORNING...THEN WILL REMOVE POPS WEST OF I-55 BY MIDDAY.
ONCE THE FRONT PASSES...SKIES WILL BECOME PARTLY TO MOSTLY SUNNY AND
WINDS WILL VEER TO THE W/SW. DUE TO A TIGHTENING PRESSURE
GRADIENT AND MIXING UP TO ABOUT 4500FT...WIND GUSTS WILL INCREASE
TO BETWEEN 25 AND 30 MPH THIS AFTERNOON. HIGH TEMPERATURES WILL
RANGE FROM AROUND 70 DEGREES IN THE ILLINOIS RIVER VALLEY...TO
THE UPPER 70S IN SOUTHEAST ILLINOIS.
&&
.LONG TERM...(TONIGHT THROUGH SUNDAY)
ISSUED AT 327 AM CDT MON MAY 11 2015
A BRIEF SHOT OF COOL/DRY AIR WILL ARRIVE IN THE WAKE OF THE COLD
FRONT TONIGHT THROUGH WEDNESDAY. HIGH TEMPERATURES ON BOTH TUESDAY
AND WEDNESDAY WILL REMAIN IN THE 60S IN MOST AREAS WHILE OVERNIGHT
LOWS DROP INTO THE 40S. THE COOLEST NIGHT OF THE ENTIRE FORECAST
PERIOD WILL BE TUESDAY NIGHT...WHEN HIGH PRESSURE ALLOWS WINDS TO GO
NEARLY CALM AND CORRESPONDING LOWS DROP INTO THE LOWER TO MIDDLE
40S.
ONCE THE HIGH SHIFTS OFF TO THE EAST...WARMER/MORE HUMID WEATHER
WILL RETURN FOR THE END OF THE WEEK AS A SOUTHWESTERLY UPPER FLOW
PATTERN RE-ESTABLISHES ITSELF. THIS MEANS NOT ONLY AN INCREASE IN
TEMPERATURES...BUT ALSO AN INCREASE IN RAIN CHANCES AS NUMEROUS WEAK
DISTURBANCES EMBEDDED WITHIN THE FLOW TRACK THROUGH THE REGION. 00Z
MAY 11 MODELS HAVE ALL SPED UP THE FIRST WAVE...WHICH IS NOW
EXPECTED TO TRACK FROM THE CENTRAL PLAINS THURSDAY MORNING TO THE
EASTERN GREAT LAKES BY FRIDAY EVENING. THIS IS ABOUT 12 HOURS
FASTER THAN PREVIOUS MODEL RUNS AND BRINGS RAIN INTO CENTRAL
ILLINOIS AS EARLY AS THURSDAY. DUE TO THE INITIALLY DRY AIRMASS IN
PLACE BENEATH THE SURFACE HIGH...WILL LIMIT POPS TO JUST THE WESTERN
CWA DURING THE DAY THURSDAY...WITH BETTER RAIN CHANCES ARRIVING
EVERYWHERE THURSDAY NIGHT INTO FRIDAY. AFTER THAT...LOW CHANCE POPS
WILL PERSIST THROUGH THE WEEKEND AS MOIST SOUTHWESTERLY FLOW
CONTINUES. HAVE INCREASED POPS LATE SUNDAY INTO MONDAY AS BETTER
FORCING ARRIVES AHEAD OF THE NEXT SIGNIFICANT WAVE. DUE TO THE
RISING UPPER HEIGHTS...TEMPS WILL CLIMB BACK INTO THE UPPER 70S AND
LOWER 80S OVER THE UPCOMING WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1154 PM CDT SUN MAY 10 2015
THERE IS A BREAK IN THE PCPN AT ALL TAF SITES SO WILL START ALL
SITES AS VFR WITH MID LEVEL CIGS. BASED ON THE CURRENT HRRR MODEL,
THIS WILL CONTINUE OVERNIGHT UNTIL THE NEXT ROUND OF PCPN ARRIVES
DURING THE EARLY MORNING HOURS. NOT EXPECTING ANOTHER LINE OF
STORMS WITH THE FRONT, THIS LOOKS LIKE IT WILL BE AN AREA OF RAIN
COMING UP/IN FROM SOUTHWESTERN MO. THIS AREA SHOULD REACH
SPI/DEC/CMI AROUND 10Z AND PIA/BMI AROUND 11Z. UNFORTUNATELY THIS
LIGHT RAIN WILL CONTINUE FOR A WHILE AND NOT MOVE EAST OF THE
SITES UNTIL THE SFC FRONT MOVES THROUGH. COULD BE SOME ISOLATED
THUNDER EMBEDDED IN THIS BUT BELIEVE ISOLATED ENOUGH TO NOT
WARRANT PUTTING IN THE NEW TAFS. PCPN WILL CONTINUE INTO THE LATE
MORNING FOR PIA AND SPI BUT LINGER AT BMI/DEC/CMI UNTIL AFTERNOON.
THEN EXPECTING VFR CONDITIONS ONCE THE PCPN ENDS AND SKIES WILL
BECOME CLEAR. WINDS WILL BE SOUTHERLY THROUGH THE BEGINNING BUT
BECOME WESTERLY LATER IN THE DAY AS THE FRONT MOVES THROUGH THE
AREA. WINDS WILL ALSO BECOME GUSTY LATE MORNING AND THEN WHEN THE
SKIES CLEAR CONTINUE TO BE GUSTY.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...AUTEN
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1154 PM CDT SUN MAY 10 2015
.UPDATE...
ISSUED AT 907 PM CDT SUN MAY 10 2015
MOST OF FORECAST LOOKS FINE...BUT WILL DEFINITELY BE UPDATING
POPS/WX FOR LINE OF STORMS MOVING OUT OF THE AREA. LINE OF
SCATTERED STORMS IN WESTERN MO COULD ARRIVE SOMETIME OVERNIGHT.
WILL TRY TO TIME THIS AND THEN UPDATE POPS/WX IN GRIDS AND
FORECAST. UPDATE WILL BE FORTHCOMING.
&&
.SHORT TERM...(TONIGHT)
ISSUED AT 257 PM CDT SUN MAY 10 2015
A WARM FRONT FROM JUST NORTH OF MACOMB TO JUST SOUTH OF PEORIA AND
NORTH OF BLOOMINGTON/NORMAL WILL SLOWLY LIFT NORTH ACROSS NORTHERN
COUNTIES THE REST OF TODAY...REACHING NORTH OF A GALESBURG TO LACON
LINE LATER THIS EVENING. SCATTERED SHOWERS AND THUNDERSTORMS ARE
EXPECTED TO DEVELOP NEAR THIS BOUNDARY LATE THIS AFTERNOON AND EARLY
EVENING. MEANWHILE AN AREA OF STRONG TO SEVERE THUNDERSTORMS WAS
MOVING NE INTO CENTRAL MO AND SW IA AND IS PROJECTED TO TRACK NE
ACROSS CENTRAL IL 5-11 PM. UNSTABLE AIRMASS SOUTH OF WARM FRONT WITH
CAPES OF 1000-2000 J/KG AND PROJECTED TO PEAK FROM 1500-2500 J/KG
BETWEEN 21Z-01Z. SPC HAS A SLIGHT RISK OF SEVERE STORMS LATE THIS
AFTERNOON AND THROUGH MID EVENING ACROSS CENTRAL IL EXCEPT THE 5 FAR
EASTERN COUNTIES ALONG THE INDIANA BORDER. SPC HAS 15-20% RISK OF
DAMAGING WIND GUSTS AND LARGE HAIL (1 INCH OR LARGER) AND 2% RISK OF
TORNADOES. STRONGER RISK OF SEVERE STORMS IS WEST OF IL OVER IA AND
MO WHERE STRONGER BULK SHEAR IS. MORE CONVECTION PROJECTED TO MOVE
INTO CENTRAL IL BY OVERNIGHT AHEAD OF AN APPROACHING COLD FRONT
MOVING TOWARD WEST CENTRAL IL BY 12Z MONDAY. SO HAVE INCREASING POPS
FROM WEST TO EAST DURING THIS EVENING AND KEPT HIGHER POPS
OVERNIGHT. LOWS TONIGHT MOSTLY IN THE MID 60S WITH COOLER LOWER 60S
BY GALESBURG.
.LONG TERM...(MONDAY THROUGH SUNDAY)
ISSUED AT 257 PM CDT SUN MAY 10 2015
MODELS HAVE COME INTO BETTER AGREEMENT WITH A SOMEWHAT FASTER COLD
FRONTAL PASSAGE ON MONDAY. THE UPSIDE TO THIS TREND IS THAT OUR
SEVERE STORM THREAT APPEARS TO BE DIMINISHING. SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO BE ONGOING ACROSS MUCH OF THE FORECAST
AREA TO START THE DAY. HOWEVER THE FRONT SHOULD QUICKLY TRACK EAST
ACROSS THE WESTERN HALF OF THE FORECAST AREA DURING THE MORNING
HOURS, WITH PRECIPITATION CHANCES QUICKLY ENDING IN ITS WAKE. AT THE
CURRENTLY EXPECTED FRONTAL SPEED, ONLY LOCATIONS EAST OF THE I-57
CORRIDOR APPEAR TO HAVE TIME TO DESTABILIZE ENOUGH TO POTENTIALLY
SUPPORT SEVERE WEATHER. CAPE VALUES EAST OF I=57 ARE PROGGED TO
APPROACH 1000 J/KG AHEAD OF THE FRONT, AND 30-40 KTS OF BULK SHEAR
IS EXPECTED ALONG THE FRONT. THIS INSTABILITY/FORCING SHOULD BE
SUFFICIENT FOR A FEW SEVERE STORMS, WITH LARGE HAIL AND DAMAGING
WINDS THE PRIMARY THREATS.
COOLER/DRIER WEATHER IS EXPECTED ACROSS CENTRAL AND SOUTHEAST
ILLINOIS MONDAY NIGHT INTO MIDWEEK BEHIND THE COLD FRONT. HOWEVER,
WHILE DAYTIME HIGHS MAY ONLY BE IN THE 60S TUESDAY AND WEDNESDAY,
THE COOL AIR NOW LOOKS MORE TO BE A GLANCING BLOW AS OPPOSED TO
PREVIOUS SIGNS OF IT LASTING SEVERAL DAYS. UPPER LEVEL HEIGHTS BUILD
AND LOW LEVEL SOUTHERLY FLOW REDEVELOPS AFTER WEDNESDAY, ALLOWING
TEMPERATURES TO QUICKLY REBOUND TO ABOVE NORMAL LEVELS BY THE END OF
THE WORK WEEK. THE RETURN OF THE MORE SUMMER-LIKE CONDITIONS WILL
ALSO SIGNAL A RETURN TO UNSETTLED WEATHER BY THE END OF THE WEEK.
THE MODELS STILL EXHIBIT SPREAD IN THE DETAILS REGARDING HOW SOON
THE RAIN CHANCES RETURN, AS WELL AS WHEN CHANCES WILL BE HIGHEST.
UNFORTUNATELY, THIS FACT HAS RESULTED IN AN EXTENDED PERIOD OF
SHOWER/STORM CHANCES FROM THURSDAY NIGHT INTO THE WEEKEND ACROSS
THE ENTIRE FORECAST AREA. THE ECMWF RETURNS ITS OCCASIONAL SUPPORT
FOR PRECIPITATION AS SOON AS THURSDAY, BUT HAVE RESTRICTED THIS
THREAT TO THE WESTERN PORTION OF THE FORECAST AREA FOR NOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1154 PM CDT SUN MAY 10 2015
THERE IS A BREAK IN THE PCPN AT ALL TAF SITES SO WILL START ALL
SITES AS VFR WITH MID LEVEL CIGS. BASED ON THE CURRENT HRRR MODEL,
THIS WILL CONTINUE OVERNIGHT UNTIL THE NEXT ROUND OF PCPN ARRIVES
DURING THE EARLY MORNING HOURS. NOT EXPECTING ANOTHER LINE OF
STORMS WITH THE FRONT, THIS LOOKS LIKE IT WILL BE AN AREA OF RAIN
COMING UP/IN FROM SOUTHWESTERN MO. THIS AREA SHOULD REACH
SPI/DEC/CMI AROUND 10Z AND PIA/BMI AROUND 11Z. UNFORTUNATELY THIS
LIGHT RAIN WILL CONTINUE FOR A WHILE AND NOT MOVE EAST OF THE
SITES UNTIL THE SFC FRONT MOVES THROUGH. COULD BE SOME ISOLATED
THUNDER EMBEDDED IN THIS BUT BELIEVE ISOLATED ENOUGH TO NOT
WARRANT PUTTING IN THE NEW TAFS. PCPN WILL CONTINUE INTO THE LATE
MORNING FOR PIA AND SPI BUT LINGER AT BMI/DEC/CMI UNTIL AFTERNOON.
THEN EXPECTING VFR CONDITIONS ONCE THE PCPN ENDS AND SKIES WILL
BECOME CLEAR. WINDS WILL BE SOUTHERLY THROUGH THE BEGINNING BUT
BECOME WESTERLY LATER IN THE DAY AS THE FRONT MOVES THROUGH THE
AREA. WINDS WILL ALSO BECOME GUSTY LATE MORNING AND THEN WHEN THE
SKIES CLEAR CONTINUE TO BE GUSTY.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AUTEN
SHORT TERM...07
LONG TERM...BAK
AVIATION...AUTEN
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
958 PM CDT TUE MAY 12 2015
.UPDATE...
ISSUED AT 955 PM CDT TUE MAY 12 2015
SATELLITE TRENDS THIS EVENING HAS A CLOUD DECK AROUND 10 KFT AGL
MOVING ACROSS NORTHERN IOWA. RAP TRENDS DEPICTS THIS REASONABLY
WELL AND HAS THE CLOUD LAYER SLOWLY DISSIPATING AS IT MOVES ACROSS
EASTERN IOWA/NORTHERN ILLINOIS.
THUS WILL UPDATE THE FORECAST TO MENTION THESE CLOUDS. CLOUD COVER
MIGHT HAVE SOME LOCALIZED AFFECTS ON LOW TEMPERATURES TONIGHT.
&&
.SYNOPSIS...
ISSUED AT 315 PM CDT TUE MAY 12 2015
AT 3 PM THE SOUTHWEST EDGE OF THE CLOUDS EXTENDED FROM ABOUT
DUBUQUE TO FREEPORT AND MAKING STEADY PROGRESS TO THE NORTHEAST.
LOW PRESSURE AND CYCLONIC FLOW WAS OVER THE GREAT LAKES WITH A
HIGH PRESSURE RIDGE EXTENDING FROM THE EASTERN DAKOTAS TO EASTERN
OKLAHOMA.
3 PM TEMPERATURES IN THE CWA RANGED FROM 53 AT FREEPORT TO THE
MID 60S IN OUR FAR SOUTH.
WEST TO NORTHWEST WINDS HAVE BEEN HOWLING ALL AFTERNOON WITH MOST
GUSTS 30 TO 35 MPH WITH ISOLATED GUSTS TO 37 MPH. THESE WINDS
WILL BE DIMINISHING BY LATE IN THE DAY AS THE GRADIENT RELAXES AND A
SPECIAL WEATHER STATEMENT COVERS THE HIGHEST GUSTS UNTIL 5 PM.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 315 PM CDT TUE MAY 12 2015
FORECAST FOCUS ON BELOW NORMAL TEMPERATURES BUT DRY.
TONIGHT...HIGH PRESSURE RIDGE WILL SETTLE INTO THE DVN CWA
ALLOWING FOR LIGHT TO CALM WINDS AND CLEAR SKIES. THIS WILL MAKE
FOR RATHER CHILLY TEMPERATURES. 850 MB TEMPERATURES START OUT NEAR
0C IN FAR NW IL BUT HEIGHTS RISE OVERNIGHT. GUIDANCE HAS BEEN
PRETTY CONSISTENT WITH LOWS RANGING FROM THE UPPER 30S FROM
DUBUQUE TO FREEPORT TO THE MID 40S IN OUR FAR SOUTH. I DECIDED
NOT TO MENTION FROST IN THE GRIDS BUT A FEW FAVORED COLD SPOTS IN
OUR FAR NORTH MAY DIP BRIEFLY TO THE MID 30S...POSSIBLY ALLOWING
FOR A TOUCH OF FROST.
WEDNESDAY...HIGH PRESSURE RIDGE WILL MOVE SLOWLY EASTWARD BUT WE
WILL STILL BE INFLUENCED BY SUBSIDENCE AND DRYING. TIME HEIGHT
SECTIONS INDICATE PLENTY OF SUNSHINE AND WITH CONSIDERABLY LESS
WIND THIS SHOULD MAKE FOR A VERY PLEASANT SPRING DAY. MAXIMUM
TEMPERATURES WILL TOP OUT AT 65 TO 70 AT MOST LOCATIONS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 315 PM CDT TUE MAY 12 2015
A SERIES OF UPPER LEVEL LOWS DROPPING INTO THE WESTERN U.S. WILL SET
UP A SW UPPER LEVEL FLOW OVER THE LOW AREA...WHICH WILL RESULT IN A
RETURN TO WARM AND UNSETTLED WEATHER LATE WEEK INTO THE WEEKEND.
THE FIRST IN A SERIES OF UPPER LEVEL SHORTWAVES WILL BRING RAIN
CHANCES AS EARLY AS WEDNESDAY NIGHT. AN 850 MB JET OF 35 TO 40
KTS...THETAE ADVECTION AND VERY MODEST MID LEVEL LAPSE RATES ARE
SHOWN FEEDING INTO THE SOUTHWEST AND FAR WESTERN PORTIONS OF THE
FORECAST AREA AFTER MIDNIGHT AND HAVE MAINTAINED CHANCE TO LOW AND
LIKELY POPS FOR SHOWERS AND ISOLATED THUNDERSTORMS. STRENGTHENING
LOW LEVEL SE WINDS IN RESPONSE TO DEVELOPING LOW PRESSURE IN THE
PLAINS WILL CONTINUE TO CIRCULATE DRY AIR FROM UNDER THE DEPARTING
HIGH. THIS WILL LEAD TO LOWS FROM AROUND 40 IN THE NORTHEAST CLOSEST
TO THE HIGH PRESSURE CENTER...TO THE MID 50S IN THE FAR SW...WHERE
CLOUD COVER MOVES IN EARLIEST AND WINDS WILL BE STRONGEST.
THURSDAY...THE MAIN PERIOD OF FORCING AHEAD OF THE UPPER LEVEL
SHORTWAVE MOVES THROUGH DURING THE DAY TO WARRANT WIDESPREAD RAIN
WITH ONLY ISOLATED THUNDERSTORMS DUE TO LIMITED INSTABILITY.
DEVELOPING LOW LEVEL WARM...MOIST ADVECTION AS WINDS VEER SLIGHTLY
MORE SOUTHERLY WILL BE NEEDED TO WARM TEMPERATURES INTO THE 60S.
HAVE TRENDED THE TIMING OF WED NIGHT AND THU POPS CLOSER TO THE
FASTER ECMWF AND NAM RUNS AS THE SLOWER TRENDING GFS IS THE ODD
MODEL OUT.
FRIDAY INTO SATURDAY...A WARM FRONT IS SHOWN SETTING UP ALONG OR
JUST NORTH OF THE HIGHWAY 20 CORRIDOR. THIS PLACES MOST OF THE
FORECAST AREA IN THE WARM...MOIST...AND POTENTIALLY UNSTABLE WARM
SECTOR THROUGH SATURDAY NIGHT AND HAVE CONTINUED CHANCES FOR SHOWERS
AND THUNDERSTORMS THROUGHOUT. GUIDANCE TEMPERATURES SHOWING HIGHS IN
THE 70S TO AROUND 80 LOOK REASONABLE WITH LOWS HELD IN THE 60S BY
SATURDAY NIGHT AS DEWPOINTS CLIMB.
SUNDAY INTO SUNDAY NIGHT...ECMWF AND GFS CONTINUE TO AGREE WITH THE
REMNANTS OF THE UPPER LOW LIFTING OUT THROUGH THE PLAINS AS A
SHORTWAVE PROVIDING UPPER LEVEL FORCING AND THEN A COLD FRONTAL
PASSAGE BY LATE EVENING OR OVERNIGHT. THIS...ALONG WITH FAVORABLE
UPPER LEVEL JET SUPPORT AND THE DEEP MOISTURE MAY SET THE STAGE FOR
SEVERE STORMS AS SUGGESTED BY SPC/S 15 PERCENT RISK SHOWING UP ON
DAY 6.
MONDAY AND TUESDAY FEATURE HIGH PRESSURE BUILDING ACROSS THE
NORTHERN PLAINS AND UPPER MS VALLEY. THIS WILL PROVIDE ANOTHER SHOT
OF COOL...DRY...AND BREEZY WEATHER WITH BELOW NORMAL
TEMPERATURES.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 627 PM CDT TUE MAY 12 2015
VFR WX WILL BE SEEN THROUGH 00Z/14 AS HIGH PRESSURE SLOWLY MOVES
THROUGH THE MIDWEST.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...08
SYNOPSIS...HAASE
SHORT TERM...HAASE
LONG TERM...SHEETS
AVIATION...08
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1202 AM CDT MON MAY 11 2015
.UPDATE...
ISSUED AT 847 PM CDT SUN MAY 10 2015
ANTICIPATE AT LEAST SCATTERED STORMS DEVELOPING AND/OR MOVING OVER
PORTIONS OF THE CWA REST OF TONIGHT UNTIL THE COLD FRONT PASSES
LATE. AS THE WARM FRONT CURRENTLY NEAR HWY 34 CORRIDOR LIFTS NORTH
OVERNIGHT WILL LIKELY SEE A WINDOW OF SURFACE BASED OPPORTUNITY
DEVELOP AS CWA THRUST IN WARM SECTOR AHEAD OF APPROACHING COLD
FRONT. STRENGTHENING MID/UPPER LEVEL WIND FIELDS OVERSPREADING
CWA ALONG WITH 0-6KM SHEAR OF 40+ KTS WOULD SUPPORT AT LEAST SOME
RISK OF SEVERE DESPITE THE NON-FAVORABLE TIMING AND CANNOT TOTALLY
DISCOUNT ISOLATED MARGINAL SEVERE WIND POSSIBLE IN THE STRONGEST
STORMS. ALSO...MONITORING TRENDS FOR POSSIBLY RAISING POPS OVER
THE SOUTHEAST THIRD OR SO OF CWA LATE TONIGHT INTO EARLY MONDAY AM
WITH LATEST FEW RUNS OF HRRR AND RAP MODELS SHOWING UPPER LEVEL
ENERGY AND ATTENDANT PCPN SHIELD OVER OK INTO NORTHWEST AR MOVING
NORTHEAST AND PHASING WITH COLD FRONT AS IT MOVES EAST OF THE
MISSISSIPPI RIVER.
WILL HAVE UPDATED ZFP/PFM OUT SOON.
&&
.SYNOPSIS...
ISSUED AT 240 PM CDT SUN MAY 10 2015
ANALYSIS AT 2 PM CDT SHOWS COOL AND CLOUDY EAST WINDS OVER ALL BUT
FAR SOUTH SECTIONS OF AREA. A BAND OF NON-SEVERE SHOWERS AND
THUNDERSTORMS IN MISSOURI TO PASS ACROSS THE AREA BETWEEN 10/21Z
AND 11/03Z. UPSTREAM ENERGY SUGGEST SHOWERS AND STORMS POSSIBLE
UNTIL EARLY MONDAY WITH SEVERE RISK LOW DUE TO LIMITED INSTABILITY
AND MARGINAL SHEAR AND FORCING WITH MOSTLY LIGHT TO MODERATE RAIN
AMOUNTS AS BEST FORCING TO OUR WEST AND SOUTHEAST.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 240 PM CDT SUN MAY 10 2015
SHORT TERM FORECAST CONFIDENCE ASSESSMENT...FAIR OR AVERAGE WITH COVERAGE
AND AMOUNTS OF NON-SEVERE STORMS THROUGH THIS EVENING WITH MOSTLY SHOWERS
INTO EARLY MONDAY. RAIN TOTALS MOSTLY QUARTER TO THREE QUARTERS AT MOST
WITH MANY LOCATIONS PICKING UP LESS THAN A QUARTER INCH.
TONIGHT...MOST OF PRECIPITATION TO FALL BY MIDNIGHT ALL BUT EAST AND
SOUTHEAST SECTIONS WITH AGAIN ONE QUARTER TO THREE QUARTERS OF AN INCH
THE MOST COMMON. LOWS LOWER 50S FAR WEST WITH CLEARING AND COOLER AIR
MOVING AND LOWER 60S EAST. LIGHT SOUTHERLY WINDS OF 5 TO 15 KTS EXCEPT
SOME GUSTS OVER 25 KTS POSSIBLE IN THE STRONGEST STORMS.
MONDAY...SHOWERS MAY CONTINUE INTO THE MID DAY HOURS OVER MOSTLY EAST
SECTIONS WITH CLEARING OVER MOST TO ALL THE AREA BY MID TO LATE AFTERNOON.
GUSTY WEST TO SOUTHWEST WINDS OF 10 TO 20+ KTS BEHIND THE FRONT WITH
HIGHS LOWER 60S WEST TO AROUND 70 DEGREES IN THE EAST.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 240 PM CDT SUN MAY 10 2015
FORECAST FOCUS ON COOL WEATHER FOR THE FIRST HALF OF THE NEW WORK
WEEK THEN WARMER WITH CHANCES FOR THUNDERSTORMS LATER IN THE WEEK
AND INTO NEXT WEEKEND.
MONDAY NIGHT THROUGH WEDNESDAY...LOW PRESSURE WILL BE TRACKING
ACROSS THE NORTHERN GREAT LAKES WITH A NORTHWEST FLOW ALOFT IN THE
WAKE OF THE SYSTEM. THIS WILL SEND BELOW NORMAL TEMPERATURES ALONG
WITH DRY WEATHER INTO THE DVN CWA. MAXIMUM TEMPERATURES ARE EXPECTED
TO BE IN THE 60S WITH LOWS MAINLY IN THE 40S. THE COOLEST NIGHT
LOOKS TO BE TUESDAY NIGHT WHEN A HIGH PRESSURE RIDGE WILL SETTLE
OVER THE AREA...BRINGING CLEAR SKIES AND LIGHT WINDS. THIS SHOULD
ALLOW FOR SOME AREAS TO DIP INTO THE MID TO UPPER 30S ESPECIALLY
ALONG HIGHWAY 20. WILL NEED TO MONITOR FOR THE POTENTIAL FOR FROST.
THURSDAY THROUGH SUNDAY...OPERATIONAL MODELS TRANSITION TO A
SOUTHWEST FLOW ALOFT ONCE AGAIN...AS A MAJOR UPPER LEVEL TROUGH
PUSHES SLOWLY EASTWARD INTO THE ROCKIES BY LATE IN THE WEEK. THIS
SYSTEM THEN LIFTS OUT INTO THE PLAINS NEXT WEEKEND. THIS WILL SET UP
THE CWA FOR PERIODS OF SHOWERS AND THUNDERSTORMS BUT TIMING OF THESE
IS DIFFICULT THIS FAR OUT IN TIME. FOR NOW WILL HAVE CHANCE POPS
EACH DAY BUT THERE WILL ALSO BE DRY PERIODS. WARMER TEMPERATURES CAN
BE EXPECTED AND BY THE TIME WE GET TO SUNDAY SOME LOCATIONS SHOULD
BE PUSHING ABOVE THE 80 DEGREE MARK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1157 PM CDT SUN MAY 10 2015
CHALLENGING TAF CYCLE IN THE SHORT TERM WITH VARIABLE CONDITIONS.
MAINLY IFR TO MVFR CONDITIONS IN FOG AND LOW CLOUDS WILL PREVAIL
AT THE NORTHERN THREE TAF SITES WITH A CHANCE OF SHOWERS AND
ISOLD STORMS UNTIL A COLD FRONT PASSES LATE TONIGHT AND EARLY
MONDAY AM. MEANWHILE... VFR AT BRL INITIALLY BUT ANTICIPATE SOME
CIGS LOWERING TO MVFR AHEAD OF COLD FRONT WITH CHANCE OF SHOWERS
AS AREA MAY BE BRUSHED BY PCPN SHIELD PASSING JUST TO SOUTHEAST.
SKIES WILL THEN DECREASE WITH VFR CONDITIONS AND WEST TO
SOUTHWEST WINDS OF 10-20 KTS AS COOLER AND DRIER AIR MOVES IN
TOWARD DAYBREAK INTO EARLY MONDAY AM. WOULD ANTICIPATE SOME
SCT-BKN STRATOCU WITH MVFR TO VFR BASES BY MID MONDAY AM THROUGH
AFTN ALONG WITH GUSTY WESTERLY WINDS AOA 10 KTS. THEN VFR
CONDITIONS MONDAY NIGHT WITH WESTERLY WINDS DECREASING BLO 10 KTS.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...05
SYNOPSIS...NICHOLS
SHORT TERM...NICHOLS
LONG TERM...HAASE
AVIATION...05
AREA FORECAST DISCUSSION
NWS PADUCAH KY
551 PM CDT MON MAY 11 2015
.UPDATE...
ISSUED AT 548 PM CDT MON MAY 11 2015
UPDATE FOR 00Z AVIATION ONLY.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 300 PM CDT MON MAY 11 2015
LEADING EDGE OF SURFACE COLD FRONTAL BOUNDARY EDGING INTO WESTERN
EDGE OF WFO PAH FORECAST AREA, STRETCHING FROM WEST OF
PINCKNEYVILLE IL, ONWARD TO PERRYVILLE AND VAN BUREN MISSOURI.
HIGH RESOLUTION GUIDANCE SUGGEST THAT LOW LEVEL CAPE FOR
CONVECTION WILL BE MINIMAL AFTER 4 PM ALONG THE EASTERN EDGE OF
THE PENNYRILE REGION OF WEST KENTUCKY. ANTICIPATE LITTLE IN THE
WAY OF WIDESPREAD AND SIGNIFICANT THUNDERSTORM ACTIVITY FOR THE
REMAINDER OF THIS FIRST PERIOD. THE HRRR GUIDANCE APPEARED TO HAVE
A GOOD HANDLE ON THE ISOLATED CONVECTION DEVELOPING AFTER 19Z OVER
THE CENTRAL PENNYRILE REGION OF WEST KENTUCKY.
BEYOND THIS AFTERNOON, HIGH PRESSURE AT THE SURFACE AND ALOFT WILL
DOMINATE THE AREA UNTIL AFTER MIDNIGHT WEDNESDAY NIGHT WHEN THE
LEADING EDGE OF LIFT, INSTABILITY AND MOISTURE MOVE INTO SOUTHEAST
MISSOURI AND SOUTHWEST ILLINOIS AHEAD OF THE NEXT SHORTWAVE
STRENGTHENS OVER THE CENTRAL ROCKIES EARLY WEDNESDAY EVENING.
ADDED A SMALL CHANCE OF THUNDERSTORMS AND BLENDED INTERNALLY AND
EXTERNALLY WITH OTHER NWS OFFICES TO REFLECT SLOW EASTWARD
PROGRESSION BY DAYBREAK ON THURSDAY.
UTILIZED A BLEND OF GFS/NAM-WRF/ECWMF BLENDED GUIDANCE FOR
TEMPERATURES AND DEWPOINTS, WITH AN EMPHASIS TOWARD LAMP/NAM-WRF
FOR DEWPOINTS, WINDS, AND SKY COVER THROUGH TUESDAY.
.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 300 PM CDT MON MAY 11 2015
THE EXTENDED PERIOD WILL BEGIN WITH A MID LEVEL SHRTWV EJECTING
OUT OF THE SWRN CONUS AND MOVING INTO THE CENTRAL PLAINS AS MOIST
RETURN FLOW BEGINS TO GET ESTABLISHED THU. THE MED RANGE MODELS
HAVE A PRETTY CONSISTENT SIGNAL WITH THIS INITIAL PCPN
GENERATOR...HOWEVER SOME MODEL SOLUTIONS SUGGEST THAT...SIMILAR TO
WHAT HAS BEEN HAPPENING LATELY...MOST OF THE ENERGY MAY BE SHUNTED
NWD...LEAVING THE PAH FORECAST AREA WITH LIMITED PCPN CHANCES THU.
ON SAT...THE MODELS DEPICT ANOTHER SHALLOWER SHRTWV EMBEDDED IN
THE SWRLY FLOW TO MOVE THROUGH OUR REGION. THOUGH THE MED RANGE
MODELS/ENSEMBLES ARE IN GOOD GENERAL AGREEMENT ON THE LARGE SCALE
FEATURES...THE SMALLER DETAILS ARE MORE VAGUE. THUS THE TIMING OF
PCPN EVENTS IS APPROXIMATE. IN FACT...MOST OF THE FORECAST
CONTAINS 30% TO 50% POPS IN EACH 12 HOUR PERIOD...THOUGH THE MODEL
BLEND INITIALIZATION PROVIDED "LIKELIES" IN SOME CASES. ONE
EXCEPTION TO THE CONSTANT POPS IS SAT NIGHT...WHERE POPS ARE
MOSTLY SLIGHT IN THE WAKE OF THE SAT SYSTEM. THE PERSISTENT SRLY
LOW LEVEL FLOW AND SWRLY FLOW ALOFT WILL CERTAINLY BE CONDUCIVE TO
KEEPING THE MOISTURE LEVELS HIGH...TO BE ACTED ON BY ENERGY ALOFT.
BY EARLY MON...ANOTHER BUNDLE OF SHRTWV ENERGY IS PROGGED TO EJECT
OUT OF THE DOMINANT SWRN CONUS TROF...DRAGGING A SFC COLD FRONT TO
ITS SOUTH. THIS SHOULD REPRESENT A GOOD BET OF SHOWER AND TSTM
DEVELOPMENT FOR THE PAH FORECAST AREA. TIMING COULD CHANGE THIS FAR
OUT IN THE FORECAST HOWEVER.
EXPECT ABOVE AVERAGE TEMPS THROUGH THE EXTENDED PERIOD.
&&
.AVIATION...
ISSUED AT 548 PM CDT MON MAY 11 2015
CLEARING SKIES WILL RESULT IN VFR CONDITIONS THROUGH THE VALID
TIME OF ALL TAF SITES. WINDS WILL STAY UP OVERNIGHT WITHOUT THE
GUSTS AND BEGIN TO SHIFT FROM WEST TO NORTHWEST AND INCREASE
AFTER SUNRISE.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...KH
SHORT TERM...SMITH
LONG TERM...DB
AVIATION...KH
AREA FORECAST DISCUSSION
NWS PADUCAH KY
301 PM CDT MON MAY 11 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 300 PM CDT MON MAY 11 2015
LEADING EDGE OF SURFACE COLD FRONTAL BOUNDARY EDGING INTO WESTERN
EDGE OF WFO PAH FORECAST AREA, STRETCHING FROM WEST OF
PINCKNEYVILLE IL, ONWARD TO PERRYVILLE AND VAN BUREN MISSOURI.
HIGH RESOLUTION GUIDANCE SUGGEST THAT LOW LEVEL CAPE FOR
CONVECTION WILL BE MINIMAL AFTER 4 PM ALONG THE EASTERN EDGE OF
THE PENNYRILE REGION OF WEST KENTUCKY. ANTICIPATE LITTLE IN THE
WAY OF WIDESPREAD AND SIGNIFICANT THUNDERSTORM ACTIVITY FOR THE
REMAINDER OF THIS FIRST PERIOD. THE HRRR GUIDANCE APPEARED TO HAVE
A GOOD HANDLE ON THE ISOLATED CONVECTION DEVELOPING AFTER 19Z OVER
THE CENTRAL PENNYRILE REGION OF WEST KENTUCKY.
BEYOND THIS AFTERNOON, HIGH PRESSURE AT THE SURFACE AND ALOFT WILL
DOMINATE THE AREA UNTIL AFTER MIDNIGHT WEDNESDAY NIGHT WHEN THE
LEADING EDGE OF LIFT, INSTABILITY AND MOISTURE MOVE INTO SOUTHEAST
MISSOURI AND SOUTHWEST ILLINOIS AHEAD OF THE NEXT SHORTWAVE
STRENGTHENS OVER THE CENTRAL ROCKIES EARLY WEDNESDAY EVENING.
ADDED A SMALL CHANCE OF THUNDERSTORMS AND BLENDED INTERNALLY AND
EXTERNALLY WITH OTHER NWS OFFICES TO REFLECT SLOW EASTWARD
PROGRESSION BY DAYBREAK ON THURSDAY.
ULILIZED A BLEND OF GFS/NAM-WRF/ECWMF BLENDED GUIDANCE FOR
TEMPERATURES AND DEWPOINTS, WITH AN EMPHASIS TOWARD LAMP/NAM-WRF
FOR DEWPOINTS, WINDS, AND SKY COVER THROUGH TUESDAY.
.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 300 PM CDT MON MAY 11 2015
THE EXTENDED PERIOD WILL BEGIN WITH A MID LEVEL SHRTWV EJECTING
OUT OF THE SWRN CONUS AND MOVING INTO THE CENTRAL PLAINS AS MOIST
RETURN FLOW BEGINS TO GET ESTABLISHED THU. THE MED RANGE MODELS
HAVE A PRETTY CONSISTENT SIGNAL WITH THIS INITIAL PCPN
GENERATOR...HOWEVER SOME MODEL SOLUTIONS SUGGEST THAT...SIMILAR TO
WHAT HAS BEEN HAPPENING LATELY...MOST OF THE ENERGY MAY BE SHUNTED
NWD...LEAVING THE PAH FORECAST AREA WITH LIMITED PCPN CHANCES THU.
ON SAT...THE MODELS DEPICT ANOTHER SHALLOWER SHRTWV EMBEDDED IN
THE SWRLY FLOW TO MOVE THROUGH OUR REGION. THOUGH THE MED RANGE
MODELS/ENSEMBLES ARE IN GOOD GENERAL AGREEMENT ON THE LARGE SCALE
FEATURES...THE SMALLER DETAILS ARE MORE VAGUE. THUS THE TIMING OF
PCPN EVENTS IS APPROXIMATE. IN FACT...MOST OF THE FORECAST
CONTAINS 30% TO 50% POPS IN EACH 12 HOUR PERIOD...THOUGH THE MODEL
BLEND INITIALIZATION PROVIDED "LIKELIES" IN SOME CASES. ONE
EXCEPTION TO THE CONSTANT POPS IS SAT NIGHT...WHERE POPS ARE
MOSTLY SLIGHT IN THE WAKE OF THE SAT SYSTEM. THE PERSISTENT SRLY
LOW LEVEL FLOW AND SWRLY FLOW ALOFT WILL CERTAINLY BE CONDUCIVE TO
KEEPING THE MOISTURE LEVELS HIGH...TO BE ACTED ON BY ENERGY ALOFT.
BY EARLY MON...ANOTHER BUNDLE OF SHRTWV ENERGY IS PROGGED TO EJECT
OUT OF THE DOMINANT SWRN CONUS TROF...DRAGGING A SFC COLD FRONT TO
ITS SOUTH. THIS SHOULD REPRESENT A GOOD BET OF SHOWER AND TSTM
DEVELOPMENT FOR THE PAH FORECAST AREA. TIMING COULD CHANGE THIS FAR
OUT IN THE FORECAST HOWEVER.
EXPECT ABOVE AVERAGE TEMPS THROUGH THE EXTENDED PERIOD.
&&
.AVIATION...
ISSUED AT 100 PM CDT MON MAY 11 2015
THE MAIN STORY IN THE TAFS IS THE WIND...WHICH SHOULD GUST AOA 20
KTS THIS AFTERNOON...ESPECIALLY IN THE ERN HALF OF THE REGION
(INCLUDING KEVV/KOWB). THIS IS ASSOCIATED WITH A WEST TO EAST COLD
FRONTAL PASSAGE. SHOWERS MAY AFFECT THE ERN TAFS THIS AFTERNOON...
BUT WITH A RATHER STABLE ATMOSPHERE IN PLACE AND AMPLE CLOUD
COVER...A TSTM DID NOT SEEM LIKELY ENOUGH TO INCLUDE IN ANY TAFS AT
THIS TIME. MVFR CIGS SHOULD BE COMMON ESPECIALLY IN THE WRN HALF OF
THE REGION BEFORE CLEARING AROUND SUNSET. AFTER SUBSIDING SOME
OVERNIGHT...WINDS SHOULD PICK UP AGAIN TUE WITH A MORE WRLY
COMPONENT.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
SHORT TERM...SMITH
LONG TERM...DB
AVIATION...DB
AREA FORECAST DISCUSSION
NWS JACKSON KY
314 PM EDT MON MAY 11 2015
.UPDATE...
ISSUED AT 311 PM EDT MON MAY 11 2015
UPDATED GRIDS TO ADD ENHANCED WORDING AND INCLUDE THE WATCH IN THE
ZONE PRODUCT. OTHERWISE QUICK FRESHENING UP OF THE GRIDS FOR
LATEST OBS AND TRENDS.
UPDATE ISSUED AT 150 PM EDT MON MAY 11 2015
DID A QUICK UPDATE TO FRESHEN UP THE GRID WITH THE LATEST OBS AND
TRENDS. UNDER MODERATELY UNSTABLE ENVIRONMENT AND CONVECTIVE
TEMPS REACHED...WE HAVE SEEN ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS FIRE UP ACROSS EASTERN KY. HOWEVER GIVEN WEAKER
SUPPORT MOST OF THE ACTIVITY HAS BEEN FAIRLY DISORGANIZED. THE
MORE ORGANIZED CONVECTION IS OCCURRING ACROSS THE SW PORTIONS OF
THE CWA THIS AFTERNOON. THE MAIN THREAT FROM THESE STORMS WILL BE
ISOLATED SEVERE WINDS AND HEAVY DOWNPOURS.
UPDATE ISSUED AT 1050 AM EDT MON MAY 11 2015
YET ANOTHER WARM DAY IS ON TAP FOR EASTERN KENTUCKY. THE BIGGEST
QUESTION FOR TODAY WILL BE WHEN AND IF CONVECTION FIRES AHEAD OF A
BOUNDARY INCHING TOWARD THE MISSISSIPPI RIVER BASED ON THE 12Z
SURFACE ANALYSIS. EARLIER RUNS OF THE HRRR HAD A MORE PRONOUNCED
AREA OF CONVECTION AHEAD OF THE MAIN OUTFLOW DRAPED TO THE WEST.
THE MORE RECENT RUNS HAVE BACK OFF ON THIS NOTION...HOWEVER STILL
BRING AREA OF CONVECTION OUT OF THE TN VALLEY AFTER 18Z. ONE OF
THE ISSUES WILL BE LACK OF SHEAR AHEAD OF THE MAIN UPPER LEVEL
SYSTEM AND LIFTING MECHANISMS. THE SPC HAS DOWNGRADED MOST OF
EASTERN KY TO A MARGINAL RISK FOR THE TODAY. THIS SEEMS REASONABLE
GIVEN THE CURRENT FORECAST ISSUES/CONFIDENCE HEADING INTO THIS
AFTERNOON. GIVEN THE UNCERTAINTY THAT REMAINS ISOLATED DAMAGING
WIND TREAT SEEMS REASONABLE AT THIS POINT...SO WILL KEEP THAT IN
THE HWO. OTHERWISE DID UPDATED GRIDS WITH LATEST OBS AND TRENDS.
UPDATE ISSUED AT 642 AM EDT MON MAY 11 2015
UPDATED FORECAST TO REFINE THE POPS THROUGH THE DAY INCLUDING THIS
EVENING. LAST 3 RUNS OF BOTH THE HRRR AND RAP HAVE SHOWN
CONVECTIVE INITIATION ALONG THE PREFRONTAL TROUGH BETWEEN 16Z AND
18Z. ALSO BASED ON THE LOCATION...ACTIVITY LOOKS TO BLOW UP OVER
EASTERN KENTUCKY THIS AFTERNOON BEFORE ADVANCING EAST INTO THE
EARLY EVENING HOURS. WITH THESE NEW TRENDS SUPPORTED BY SEVERAL
RUNS OF THE HI RES MODELS...HAVE OPTED TO PUT THE HIGHEST POPS
BETWEEN 17Z AND 23Z THIS AFTERNOON AND EARLY EVENING. GIVEN THE
EARLIER CONVECTION...WOULD NOT EXPECT MUCH TO SPREAD ACROSS THE
AREA AFTER 00Z TONIGHT GIVEN THE ATMOSPHERE WILL BE WORKED OVER
AND THUS...LITTLE TO NO INSTABILITY TO WORK WITH. THUS...HAVE
TRIMMED BACK POPS CONSIDERABLY FOR THE TONIGHT PORTION OF THE
FORECAST. STILL APPEARS THE MAIN THREAT WITH STORMS WILL BE
DAMAGING WINDS...BUT SOME HAIL COULD ALSO OCCUR. DUE TO THE
UNIDIRECTIONAL FLOW FROM SURFACE TO 700MB...WOULD NOT EXPECT MUCH
OF A TORNADO THREAT TODAY. GIVEN THE CHANGE IN POPS...ALSO
ADJUSTED CLOUD COVER AND TEMPERATURES.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 342 AM EDT MON MAY 11 2015
UPPER LEVEL RIDGING REMAINS OVER THE EASTERN CONUS THIS MORNING
WITH TROPICAL DEPRESSION ANA MOVING NORTH ACROSS EASTERN NORTH
CAROLINA. CONVECTION OVERNIGHT ACROSS WESTERN KENTUCKY SENT A GUST
FRONT TO THE EAST WHERE IT CURRENTLY RESIDES FROM NEAR
FLEMINGSBURG...SOUTH TO SOMERSET. HOW THIS BOUNDARY MIGHT IMPACT
LATER CONVECTION IS STILL TO BE DETERMINED. ONLY SHOWERS AND
STORMS TO EVEN COME CLOSE TO THE AREA OVERNIGHT HAVE BEEN OVER
WEST VIRGINIA...FUELED BY OUTFLOW FROM STORMS YESTERDAY EVENING.
A SHORTWAVE TROUGH CONTINUES TO GENERATE ROUNDS OF SHOWERS AND
STORMS OVER THE SOUTHERN MISSISSIPPI RIVER VALLEY THIS MORNING.
THIS SHORTWAVE TROUGH WILL LIFT NORTHEAST TODAY INTO TONIGHT...
GENERATING MORE SHOWERS AND STORMS ACROSS THE OHIO RIVER VALLEY BY
THIS AFTERNOON/EVENING. BEST FORCING AND LIFT WILL RESIDE TO OUR
NORTH AND NORTHWEST THROUGH THE DAY AND EVEN TONIGHT. THIS WILL
LEAVE EASTERN KENTUCKY IN A VERY SIMILAR PATTERN THE PAST SEVERAL
DAYS WITH THE THREAT OF ISOLATED SHOWERS AND STORMS. IF THE
OUTFLOW BOUNDARY STALLS OVER THE AREA THIS MORNING...THIS MAY
SERVE AS THE FOCUS FOR SHOWERS AND STORMS TO DEVELOP LATER THIS
AFTERNOON WITH PEAK HEATING. WITH THE SHORTWAVE TROUGH FINALLY ON
THE MOVE INTO THE GREAT LAKES...A COLD FRONT WILL PUSH EAST WITH
THE GRADIENT TIGHTENING UP OVER THE AREA. THIS WILL YIELD
INCREASING WIND SHEAR AS WE HEAD THROUGH THE DAY. THUS...ANY
SHOWERS OR STORMS THAT DO MANAGE TO POP UP THIS AFTERNOON OR
EVENING WOULD HAVE THE POTENTIAL TO BECOME SEVERE. FLOW IS FAIRLY
UNIDIRECTIONAL...SO MAIN THREATS WOULD BE STRAIGHT LINE WINDS.
HAIL THREAT MAY BE THERE TOO IF INSTABILITY CAN BUILD ENOUGH PRIOR
TO STORM INITIATION...BUT FREEZING LEVELS ARE UP NEAR 12KFT
AGL...SO IT WILL TAKE SOME HEFTY UPDRAFTS TO GENERATE HAIL TODAY.
GIVEN THE SEVERE THREAT...THE AREA HAS BEEN PLACED IN A SLIGHT
RISK AREA FOR SEVERE THUNDERSTORMS BY THE SEVERE STORMS PREDICTION
CENTER.
THERE IS SOME WEAK FORCING THAT WILL PUSH ACROSS THE AREA
THIS EVENING AND HENCE THE BEST OPPORTUNITY FOR BETTER COVERAGE IN
SHOWERS AND STORMS. HOWEVER...LATEST HI-RES MODELS DO NOT SHOW
MUCH MOVING INTO THE AREA THIS EVENING...SO CONFIDENCE IS FAIRLY
LOW ON CONVECTION THIS EVENING AS OF RIGHT NOW. THUS...WILL STAY
WITH THE CHANCE POPS WITH THE PREVIOUS FORECAST. IF CONVECTION
FORMS...IT SHOULD BE ON THE WAY OUT BY MIDNIGHT...WITH SUBSIDENCE
BUILDING BEHIND THE DEPARTING STORMS. THE COLD FRONT WILL LAG WELL
BEHIND THE CONVECTION AND WILL NOT MAKE ITS MOVE ACROSS THE AREA
UNTIL TUESDAY MORNING...WHEN ANOTHER ISOLATED SHOWER MAY BE
POSSIBLE. IF THE FRONT HANGS UP TOO MUCH ON TUESDAY...MAY NEED TO
WATCH POTENTIAL FOR A FEW STORMS TO FIRE UP ON THE BOUNDARY AS IT
SLIPS ACROSS THE AREA. AS IT STANDS NOW...IT SHOULD MOVE THROUGH
IN TIME TO PREVENT THIS FROM HAPPENING. TUESDAY WILL BE COOLER
WITH DRIER AIR ADVECTING INTO THE AREA...THIS WILL MAKE FOR A
PLEASANT AFTERNOON.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 342 AM EDT MON MAY 11 2015
THE EXTENDED FORECAST PERIOD BEGINS ON TUESDAY NIGHT WITH UPPER
LEVEL RIDGING OVER THE REGION KEEPING EASTERN KENTUCKY DRY THROUGH
THE WEDNESDAY AND MUCH OF THURSDAY TIME PERIOD. THIS PATTERN SEEMS
TO TAKE A CHANGE AS THE PATTERN BECOMES MORE ACTIVE AND A STRONG
SHORTWAVE MOVES OUT OF THE SOUTHWESTERN CONUS AND TRAVELS OVER THE
RIDGE AND INTO THE UPPER PLAINS AND GREAT LAKES BY FRIDAY. THIS NOT
ONLY BRINGS SOME UPPER LEVEL SUPPORT INTO THE OH VALLEYS REGION BUT
ALSO OPENS THE GULF AS SOME MID LEVEL MOISTURE ADVECTS INTO THE
REGION. ALSO DURING THIS TIME ON FRIDAY...A STRONG CLOSED LOW COMES
ASHORE IN SOUTHERN CA. THIS FEATURE STANDS TO BRING A GOOD SHOT OF
UPPER LEVEL ENERGY TO THE PLAINS AND EVEN INTO THE MIDWEST BY
SUNDAY. THE EURO AND GFS ARE SIMILAR IN THIS TREND.
CLOSER TO THE SURFACE...THE APPROACH OF THE FIRST MENTIONED
SHORTWAVE WILL BRING INCREASED SOUTHERLY LOW LEVEL FLOW INTO THE
AREA AND AS THE RIDGE WEAKENS...CONVECTION WILL BECOME MORE AND MORE
PREVALENT...ESPECIALLY BY FRIDAY. A BOUNDARY SHOULD BEGIN TO FORM
TO THE NORTH OF THE OH RIVER WITH PLENTY OF CONVECTION BY FRIDAY
AFTERNOON AND AS WELL INTO THE WEEKEND. THIS LEAVES EASTERN
KENTUCKY IN A WARM...HUMID...AND UNSTABLE PATTERN WITH DIURNALLY
DRIVEN CONVECTION. BY SUNDAY HOWEVER...THE MENTIONED STRONG LOW
THAT CAME ASHORE OVER SOCA WILL MOVE INTO THE UPPER MIDWEST
DRAGGING A POTENT COLD FRONT TO THE OH VALLEY DOORSTEP.
THE EURO AND GFS DO SHOW SOME CONSISTENCY HERE. THE SUPER BLEND DID
COME IN RATHER HIGH IN POPS...ESPECIALLY FOR FRIDAY. TRENDS OF THE
RIDGE MIGHT BE ENOUGH TO SUPPRESS CONVECTION ENOUGH THAT LIKELY POPS
SEEM A BIT...UNLIKELY...AND SO LOWERED THEM DURING THIS TIME FRAME
AS WELL. ALSO THE BLEND HAD NO INDICATION OF ANY SORT OF DIURNALLY
TREND TO THE CONVECTION AND GIVEN WHAT THE AREA HAS EXPERIENCED THIS
PAST WEEK...THIS SEEMS TO BE A REPEAT OF SORTS. DID THEN ADDRESS
THIS WITH THE NEIGHBORING OFFICES AND MADE THESE ADJUSTMENTS TO THE
POPS INHERITED BY THE SUPER BLEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 133 PM EDT MON MAY 11 2015
THIS AFTERNOON WE HAVE SEEN CONVECTION FIRE UP ACROSS PORTIONS OF
EASTERN KY. THESE ISOLATED TO SCATTER STORMS WILL BE THE BIGGEST
CONCERN FOR THE NEXT FEW HOURS. IT DOES LOOK LIKE THERE COULD BE
TWO ROUND...ONE ONGOING CONVECTION MORE DIURNALLY DRIVEN UNDER
MODERATELY UNSTABLE ENVIRONMENT...TWO THE COLD FRONT AND ANY
OUTFLOWS AHEAD OF THE FRONT. THE SECOND LINE IS IN QUESTION GIVEN
THAT STORMS HAVE ALREADY FIRED AND COULD TAP OUT THE CURRENT
UNSTABLE ENVIRONMENT. THE BIGGEST THREAT FROM THIS AVIATION WISE
LOOKS TO BE THE POTENTIAL FOR GUSTY WINDS AND REDUCED VIS.
OTHERWISE OVERNIGHT SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DIE
OFF WITH DAYTIME HEATING AND FRONT SWEEPING ACROSS THE REGION.
THE OTHER ISSUE TONIGHT WILL BE POTENTIAL FOR FOG AND/OR LOW
STRATUS DECK. RIGHT NOW PLAN TO KEEP LOW STRATUS DECK WITH
POTENTIAL FOR AT LEAST MVFR CEILINGS OVERNIGHT INTO EARLY
TUESDAY. HIGH PRESSURE WILL RETURN TOMORROW WITH CLEARING SKIES.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...DJ
SHORT TERM...KAS
LONG TERM...KAS
AVIATION...DJ
AREA FORECAST DISCUSSION
NWS PADUCAH KY
100 PM CDT MON MAY 11 2015
UPDATE...
ISSUED AT 100 PM MON MAY 11 2015 UPDATED AVIATION SECTION ONLY.
&&
UPDATE...
ISSUED AT 1200 PM CDT MON MAY 11 2015
QUICK UPDATE TO REFLECT SHORT TERM TRENDS THIS AFTERNOON WITH
RESPECT TO CONVECTIVE ACTIVITY AND SENSIBLE WEATHER ELEMENTS. ANY
LOCALIZED BREAKS IN THE CLOUD COVER MAY CAUSE SLIGHT ELEVATION IN
TEMPERATURES BY 1-3 DEGREES ABOVE CURRENT FORECAST.
ANTICIPATE MOST OF THE CONVECTION THIS AFTERNOON MAY REMAIN
SOMEWHAT ELEVATED WITH THE APPROACHING FRONT, THE FRONTAL LOCATION
SUGGESTED BY THE FINE LINE ON THE KLSX RADAR ALONG AND EAST OF
THE MISSISSIPPI RIVER. SPC MARGINAL RISK FOR SEVERE STORMS SEEMS
SOMEWHAT OPTIMISTIC, BUT THE POTENTIAL FOR SOME SURFACE-BASED
CONVECTION WILL STILL REMAIN POSSIBLE OVER THE EASTERN PARTS OF
SOUTHWEST INDIANA AND THE PENNYRILE REGION OF WEST KENTUCKY
BETWEEN NOON AND 5 PM.
ISSUED A SPECIAL WEATHER STATEMENT FOR GUSTY WINDS AHEAD OF THE
FRONT IN SOUTHWEST INDIANA AND WEST KENTUCKY OUTSIDE OF CONVECTION
THIS AFTERNOON...MAINLY FOR BOATERS AND TRAVELERS ON THE ROAD.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 343 AM CDT MON MAY 11 2015
THE LARGE AREA OF CONVECTION THAT HAS BEEN ADVERTISED FOR
DAYS...HAS DEVELOPED RIGHT ON SCHEDULE EARLY THIS MORNING ACROSS
SOUTHEAST MISSOURI. THE PREPONDERANCE OF SHORT TERM GUIDANCE LIFTS
THE BAND NORTH NORTHEAST THROUGH SOUTHEAST MISSOURI AND SOUTHERN
ILLINOIS THROUGH THE MORNING HOURS...WITH THE TAIL END OF IT
DISSIPATING AS IT MOVES EAST THROUGH WEST KENTUCKY AND SOUTHWEST
INDIANA. THIS LARGE AREA OF CONVECTION SEEMS TO BE ASSOCIATED
WITH AN UPPER-LEVEL JET LIFTING NORTHWARD OUT OF THE AREA BY THIS
AFTERNOON.
THE BIG QUESTION IS WHAT WILL HAPPEN THIS AFTERNOON OVER WEST
KENTUCKY AND SOUTHWEST INDIANA. IT LOOKS LIKE SCATTERED CONVECTION
AT BEST...AS THE 06Z HRRR HAS NEXT TO NOTHING LEFT IN THE EAST
AFTER 17Z. THE POPS WITH THIS FORECAST PACKAGE ARE LIKELY TOO
WET IN THE EAST THIS AFTERNOON.
AS FOR SEVERE...WILL KEEP AN EYE ON RADAR THROUGH DAYBREAK...BUT
IT APPEARS THAT THERE ARE JUST TOO MANY UPDRAFTS FOR ANY ONE OF
THEM TO GET CLOSE TO SEVERE LEVELS. HAVE NOT SEEN ANYTHING SO FAR
THAT WAS ORIENTED IN SUCH A WAY AS TO CATCH THE ENVIRONMENTAL
WINDS...AND NOT SURE IF THE STRONGER WINDS WOULD REACH THE GROUND
GIVEN THE ELEVATED NATURE OF THE STORMS.
ANY STORM THAT GETS GOING IN THE EAST THIS AFTERNOON WOULD HAVE
SOME POTENTIAL TO BE SEVERE...BUT WIND FIELDS ARE STILL A BIT
SUSPECT...WITH MODEL SOUNDINGS INDICATING BACKING WINDS WITH
HEIGHT IN THE LOW-LEVELS. OF COURSE...WITH THE POTENTIAL FOR
CONVECTIVE DEVELOPMENT IN DOUBT THIS AFTERNOON...THE SEVERE
PROBABILITIES ARE RATHER LOW. BETTER CHANCES FOR SEVERE WOULD
SEEM TO BE EAST AND NORTHEAST OF OUR AREA.
IT STILL LOOKS LIKE THE CONVECTION WILL BE WELL EAST OF THE AREA
BY 00Z TUESDAY...AND THE REMAINDER OF THE SHORT TERM WILL BE
DRY WITH SURFACE HIGH PRESSURE DOMINATING THE REGION. CONSIDERED
INSERTING A SLIGHT CHANCE POP WEDNESDAY NIGHT IN THE FAR
WEST...BUT A GFS SOUNDING FROM THAT AREA WAS UNINSPIRING.
SOUTHWEST WINDS FROM MID-MORNING THROUGH MID AFTERNOON ARE
FORECAST TO BE AT OR ABOVE LAKE WIND ADVISORY CRITERIA OVER THE
EASTERN HALF OF THE AREA. HOWEVER...CONFIDENCE IN THE CONVECTIVE
EVOLUTION CASTS SOME DOUBT ON THE WIND FORECAST...SO WILL NOT
ISSUE AN ADVISORY AT THIS TIME. WILL LET THE DAY SHIFT MONITOR
TRENDS THIS MORNING AND ISSUE IF/WHEN IT BECOMES MORE OBVIOUS.
WEST NORTHWEST WINDS OVER THE NORTHERN HALF OF THE AREA WILL BE
NEAR CRITERIA ON TUESDAY AS WELL.
GENERALLY STAYED CLOSE TO THE CONSENSUS OF GUIDANCE FOR TEMPERATURES
THROUGH THE PERIOD. MAY NOT BE COLD ENOUGH TUESDAY NIGHT...WITH
DECENT RADIATIONAL COOLING REGIME AND DRY AIR IN PLACE.
.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 343 AM CDT MON MAY 11 2015
ON THE LARGER SCALE...OPERATIONAL MODELS AND THEIR ENSEMBLES ARE IN
RELATIVELY GOOD AGREEMENT THROUGH THE EXTENDED PERIOD. HOWEVER...
MUCH OF THE WEATHER DURING THIS TIME WILL BE DRIVEN BY SUBTLE
MESOSCALE FEATURES THAT RESULT IN RELATIVELY WEAK FORCING. AS A
RESULT...OUR CONFIDENCE IS ONLY AVERAGE AT BEST DURING THIS TIME.
THE UPPER LEVEL PATTERN THROUGH THE WEEKEND WILL BE DOMINATED BY A
RIDGE POSITIONED FROM THE GULF COAST NORTHWARD ACROSS THE EASTERN
HALF OF THE NATION. A LARGE UPPER LEVEL LOW OVER THE EASTERN PACIFIC
IS FORECAST TO SLOWLY MIGRATE EAST INTO THE INTERMOUNTAIN WEST LATE
IN THE WEEK...REACHING THE PLAINS LATE IN THE WEEKEND.
AS FOR THE DETAILS...HIGH PRESSURE WILL SHIFT EAST OF THE REGION BY
THURSDAY. AN UPPER LEVEL DISTURBANCE IS FORECAST TO TRACK ACROSS THE
MIDDLE AND UPPER MISSISSIPPI RIVER VALLEYS AS A WARM FRONT LIFTS
NORTH ACROSS THE REGION THURSDAY AND THURSDAY NIGHT. THE RESULTANT
INCREASE IN MOISTURE AND INSTABILITY WILL LEAD TO OUR NEXT CHANCE OF
SHOWERS AND THUNDERSTORMS DURING THIS TIME.
BY FRIDAY AND SATURDAY...THE UPPER LEVEL RIDGE BECOMES THE DOMINANT
WEATHER FEATURE. HOWEVER...RATHER WARM AND HUMID CONDITIONS WILL
PREVAIL BENEATH THIS RIDGE. EVEN THOUGH ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS CERTAINLY CANNOT BE RULED OUT...FORECAST
MODELS APPEAR TO BE OVERDONE WITH RESPECT TO PRECIPITATION CHANCES
AND COVERAGE. AS A RESULT...WE COLLABORATED WITH SURROUNDING OFFICES
TO REDUCE RAIN CHANCES TO NO HIGHER THAN 30-40 PERCENT DURING THIS
TIME. RAIN CHANCES SHOULD INCREASE LATE IN THE WEEKEND AS THE
REMNANTS OF THE UPPER LOW DRAW CLOSER.
TEMPERATURES WILL UNDERGO A SLOW WARMING TREND THROUGH THE PERIOD.
HIGHS WILL START OFF IN THE MID TO UPPER 70S ON THURSDAY...THEN
MODERATE INTO THE LOWER AND PERHAPS MID 80S BY THE WEEKEND. LOWS OF
50 TO 55 THURSDAY MORNING WILL RISE INTO THE LOWER AND MID 60S
DURING THE REMAINDER OF THE PERIOD.
&&
.AVIATION...
ISSUED AT 100 PM CDT MON MAY 11 2015
THE MAIN STORY IN THE TAFS IS THE WIND...WHICH SHOULD GUST AOA 20
KTS THIS AFTERNOON...ESPECIALLY IN THE ERN HALF OF THE REGION
(INCLUDING KEVV/KOWB). THIS IS ASSOCIATED WITH A WEST TO EAST COLD
FRONTAL PASSAGE. SHOWERS MAY AFFECT THE ERN TAFS THIS AFTERNOON...
BUT WITH A RATHER STABLE ATMOSPHERE IN PLACE AND AMPLE CLOUD
COVER...A TSTM DID NOT SEEM LIKELY ENOUGH TO INCLUDE IN ANY TAFS AT
THIS TIME. MVFR CIGS SHOULD BE COMMON ESPECIALLY IN THE WRN HALF OF
THE REGION BEFORE CLEARING AROUND SUNSET. AFTER SUBSIDING SOME
OVERNIGHT...WINDS SHOULD PICK UP AGAIN TUE WITH A MORE WRLY
COMPONENT.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...SMITH
SHORT TERM...DRS
LONG TERM...RJP
AVIATION...DB
AREA FORECAST DISCUSSION
NWS JACKSON KY
150 PM EDT MON MAY 11 2015
.UPDATE...
ISSUED AT 150 PM EDT MON MAY 11 2015
DID A QUICK UPDATE TO FRESHEN UP THE GRID WITH THE LATEST OBS AND
TRENDS. UNDER MODERATELY UNSTABLE ENVIRONMENT AND CONVECTIVE
TEMPS REACHED...WE HAVE SEEN ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS FIRE UP ACROSS EASTERN KY. HOWEVER GIVEN WEAKER
SUPPORT MOST OF THE ACTIVITY HAS BEEN FAIRLY DISORGANIZED. THE
MORE ORGANIZED CONVECTION IS OCCURRING ACROSS THE SW PORTIONS OF
THE CWA THIS AFTERNOON. THE MAIN THREAT FROM THESE STORMS WILL BE
ISOLATED SEVERE WINDS AND HEAVY DOWNPOURS.
UPDATE ISSUED AT 1050 AM EDT MON MAY 11 2015
YET ANOTHER WARM DAY IS ON TAP FOR EASTERN KENTUCKY. THE BIGGEST
QUESTION FOR TODAY WILL BE WHEN AND IF CONVECTION FIRES AHEAD OF A
BOUNDARY INCHING TOWARD THE MISSISSIPPI RIVER BASED ON THE 12Z
SURFACE ANALYSIS. EARLIER RUNS OF THE HRRR HAD A MORE PRONOUNCED
AREA OF CONVECTION AHEAD OF THE MAIN OUTFLOW DRAPED TO THE WEST.
THE MORE RECENT RUNS HAVE BACK OFF ON THIS NOTION...HOWEVER STILL
BRING AREA OF CONVECTION OUT OF THE TN VALLEY AFTER 18Z. ONE OF
THE ISSUES WILL BE LACK OF SHEAR AHEAD OF THE MAIN UPPER LEVEL
SYSTEM AND LIFTING MECHANISMS. THE SPC HAS DOWNGRADED MOST OF
EASTERN KY TO A MARGINAL RISK FOR THE TODAY. THIS SEEMS REASONABLE
GIVEN THE CURRENT FORECAST ISSUES/CONFIDENCE HEADING INTO THIS
AFTERNOON. GIVEN THE UNCERTAINTY THAT REMAINS ISOLATED DAMAGING
WIND TREAT SEEMS REASONABLE AT THIS POINT...SO WILL KEEP THAT IN
THE HWO. OTHERWISE DID UPDATED GRIDS WITH LATEST OBS AND TRENDS.
UPDATE ISSUED AT 642 AM EDT MON MAY 11 2015
UPDATED FORECAST TO REFINE THE POPS THROUGH THE DAY INCLUDING THIS
EVENING. LAST 3 RUNS OF BOTH THE HRRR AND RAP HAVE SHOWN
CONVECTIVE INITIATION ALONG THE PREFRONTAL TROUGH BETWEEN 16Z AND
18Z. ALSO BASED ON THE LOCATION...ACTIVITY LOOKS TO BLOW UP OVER
EASTERN KENTUCKY THIS AFTERNOON BEFORE ADVANCING EAST INTO THE
EARLY EVENING HOURS. WITH THESE NEW TRENDS SUPPORTED BY SEVERAL
RUNS OF THE HI RES MODELS...HAVE OPTED TO PUT THE HIGHEST POPS
BETWEEN 17Z AND 23Z THIS AFTERNOON AND EARLY EVENING. GIVEN THE
EARLIER CONVECTION...WOULD NOT EXPECT MUCH TO SPREAD ACROSS THE
AREA AFTER 00Z TONIGHT GIVEN THE ATMOSPHERE WILL BE WORKED OVER
AND THUS...LITTLE TO NO INSTABILITY TO WORK WITH. THUS...HAVE
TRIMMED BACK POPS CONSIDERABLY FOR THE TONIGHT PORTION OF THE
FORECAST. STILL APPEARS THE MAIN THREAT WITH STORMS WILL BE
DAMAGING WINDS...BUT SOME HAIL COULD ALSO OCCUR. DUE TO THE
UNIDIRECTIONAL FLOW FROM SURFACE TO 700MB...WOULD NOT EXPECT MUCH
OF A TORNADO THREAT TODAY. GIVEN THE CHANGE IN POPS...ALSO
ADJUSTED CLOUD COVER AND TEMPERATURES.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 342 AM EDT MON MAY 11 2015
UPPER LEVEL RIDGING REMAINS OVER THE EASTERN CONUS THIS MORNING
WITH TROPICAL DEPRESSION ANA MOVING NORTH ACROSS EASTERN NORTH
CAROLINA. CONVECTION OVERNIGHT ACROSS WESTERN KENTUCKY SENT A GUST
FRONT TO THE EAST WHERE IT CURRENTLY RESIDES FROM NEAR
FLEMINGSBURG...SOUTH TO SOMERSET. HOW THIS BOUNDARY MIGHT IMPACT
LATER CONVECTION IS STILL TO BE DETERMINED. ONLY SHOWERS AND
STORMS TO EVEN COME CLOSE TO THE AREA OVERNIGHT HAVE BEEN OVER
WEST VIRGINIA...FUELED BY OUTFLOW FROM STORMS YESTERDAY EVENING.
A SHORTWAVE TROUGH CONTINUES TO GENERATE ROUNDS OF SHOWERS AND
STORMS OVER THE SOUTHERN MISSISSIPPI RIVER VALLEY THIS MORNING.
THIS SHORTWAVE TROUGH WILL LIFT NORTHEAST TODAY INTO TONIGHT...
GENERATING MORE SHOWERS AND STORMS ACROSS THE OHIO RIVER VALLEY BY
THIS AFTERNOON/EVENING. BEST FORCING AND LIFT WILL RESIDE TO OUR
NORTH AND NORTHWEST THROUGH THE DAY AND EVEN TONIGHT. THIS WILL
LEAVE EASTERN KENTUCKY IN A VERY SIMILAR PATTERN THE PAST SEVERAL
DAYS WITH THE THREAT OF ISOLATED SHOWERS AND STORMS. IF THE
OUTFLOW BOUNDARY STALLS OVER THE AREA THIS MORNING...THIS MAY
SERVE AS THE FOCUS FOR SHOWERS AND STORMS TO DEVELOP LATER THIS
AFTERNOON WITH PEAK HEATING. WITH THE SHORTWAVE TROUGH FINALLY ON
THE MOVE INTO THE GREAT LAKES...A COLD FRONT WILL PUSH EAST WITH
THE GRADIENT TIGHTENING UP OVER THE AREA. THIS WILL YIELD
INCREASING WIND SHEAR AS WE HEAD THROUGH THE DAY. THUS...ANY
SHOWERS OR STORMS THAT DO MANAGE TO POP UP THIS AFTERNOON OR
EVENING WOULD HAVE THE POTENTIAL TO BECOME SEVERE. FLOW IS FAIRLY
UNIDIRECTIONAL...SO MAIN THREATS WOULD BE STRAIGHT LINE WINDS.
HAIL THREAT MAY BE THERE TOO IF INSTABILITY CAN BUILD ENOUGH PRIOR
TO STORM INITIATION...BUT FREEZING LEVELS ARE UP NEAR 12KFT
AGL...SO IT WILL TAKE SOME HEFTY UPDRAFTS TO GENERATE HAIL TODAY.
GIVEN THE SEVERE THREAT...THE AREA HAS BEEN PLACED IN A SLIGHT
RISK AREA FOR SEVERE THUNDERSTORMS BY THE SEVERE STORMS PREDICTION
CENTER.
THERE IS SOME WEAK FORCING THAT WILL PUSH ACROSS THE AREA
THIS EVENING AND HENCE THE BEST OPPORTUNITY FOR BETTER COVERAGE IN
SHOWERS AND STORMS. HOWEVER...LATEST HI-RES MODELS DO NOT SHOW
MUCH MOVING INTO THE AREA THIS EVENING...SO CONFIDENCE IS FAIRLY
LOW ON CONVECTION THIS EVENING AS OF RIGHT NOW. THUS...WILL STAY
WITH THE CHANCE POPS WITH THE PREVIOUS FORECAST. IF CONVECTION
FORMS...IT SHOULD BE ON THE WAY OUT BY MIDNIGHT...WITH SUBSIDENCE
BUILDING BEHIND THE DEPARTING STORMS. THE COLD FRONT WILL LAG WELL
BEHIND THE CONVECTION AND WILL NOT MAKE ITS MOVE ACROSS THE AREA
UNTIL TUESDAY MORNING...WHEN ANOTHER ISOLATED SHOWER MAY BE
POSSIBLE. IF THE FRONT HANGS UP TOO MUCH ON TUESDAY...MAY NEED TO
WATCH POTENTIAL FOR A FEW STORMS TO FIRE UP ON THE BOUNDARY AS IT
SLIPS ACROSS THE AREA. AS IT STANDS NOW...IT SHOULD MOVE THROUGH
IN TIME TO PREVENT THIS FROM HAPPENING. TUESDAY WILL BE COOLER
WITH DRIER AIR ADVECTING INTO THE AREA...THIS WILL MAKE FOR A
PLEASANT AFTERNOON.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 342 AM EDT MON MAY 11 2015
THE EXTENDED FORECAST PERIOD BEGINS ON TUESDAY NIGHT WITH UPPER
LEVEL RIDGING OVER THE REGION KEEPING EASTERN KENTUCKY DRY THROUGH
THE WEDNESDAY AND MUCH OF THURSDAY TIME PERIOD. THIS PATTERN SEEMS
TO TAKE A CHANGE AS THE PATTERN BECOMES MORE ACTIVE AND A STRONG
SHORTWAVE MOVES OUT OF THE SOUTHWESTERN CONUS AND TRAVELS OVER THE
RIDGE AND INTO THE UPPER PLAINS AND GREAT LAKES BY FRIDAY. THIS NOT
ONLY BRINGS SOME UPPER LEVEL SUPPORT INTO THE OH VALLEYS REGION BUT
ALSO OPENS THE GULF AS SOME MID LEVEL MOISTURE ADVECTS INTO THE
REGION. ALSO DURING THIS TIME ON FRIDAY...A STRONG CLOSED LOW COMES
ASHORE IN SOUTHERN CA. THIS FEATURE STANDS TO BRING A GOOD SHOT OF
UPPER LEVEL ENERGY TO THE PLAINS AND EVEN INTO THE MIDWEST BY
SUNDAY. THE EURO AND GFS ARE SIMILAR IN THIS TREND.
CLOSER TO THE SURFACE...THE APPROACH OF THE FIRST MENTIONED
SHORTWAVE WILL BRING INCREASED SOUTHERLY LOW LEVEL FLOW INTO THE
AREA AND AS THE RIDGE WEAKENS...CONVECTION WILL BECOME MORE AND MORE
PREVALENT...ESPECIALLY BY FRIDAY. A BOUNDARY SHOULD BEGIN TO FORM
TO THE NORTH OF THE OH RIVER WITH PLENTY OF CONVECTION BY FRIDAY
AFTERNOON AND AS WELL INTO THE WEEKEND. THIS LEAVES EASTERN
KENTUCKY IN A WARM...HUMID...AND UNSTABLE PATTERN WITH DIURNALLY
DRIVEN CONVECTION. BY SUNDAY HOWEVER...THE MENTIONED STRONG LOW
THAT CAME ASHORE OVER SOCA WILL MOVE INTO THE UPPER MIDWEST
DRAGGING A POTENT COLD FRONT TO THE OH VALLEY DOORSTEP.
THE EURO AND GFS DO SHOW SOME CONSISTENCY HERE. THE SUPER BLEND DID
COME IN RATHER HIGH IN POPS...ESPECIALLY FOR FRIDAY. TRENDS OF THE
RIDGE MIGHT BE ENOUGH TO SUPPRESS CONVECTION ENOUGH THAT LIKELY POPS
SEEM A BIT...UNLIKELY...AND SO LOWERED THEM DURING THIS TIME FRAME
AS WELL. ALSO THE BLEND HAD NO INDICATION OF ANY SORT OF DIURNALLY
TREND TO THE CONVECTION AND GIVEN WHAT THE AREA HAS EXPERIENCED THIS
PAST WEEK...THIS SEEMS TO BE A REPEAT OF SORTS. DID THEN ADDRESS
THIS WITH THE NEIGHBORING OFFICES AND MADE THESE ADJUSTMENTS TO THE
POPS INHERITED BY THE SUPER BLEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 133 PM EDT MON MAY 11 2015
THIS AFTERNOON WE HAVE SEEN CONVECTION FIRE UP ACROSS PORTIONS OF
EASTERN KY. THESE ISOLATED TO SCATTER STORMS WILL BE THE BIGGEST
CONCERN FOR THE NEXT FEW HOURS. IT DOES LOOK LIKE THERE COULD BE
TWO ROUND...ONE ONGOING CONVECTION MORE DIURNALLY DRIVEN UNDER
MODERATELY UNSTABLE ENVIRONMENT...TWO THE COLD FRONT AND ANY
OUTFLOWS AHEAD OF THE FRONT. THE SECOND LINE IS IN QUESTION GIVEN
THAT STORMS HAVE ALREADY FIRED AND COULD TAP OUT THE CURRENT
UNSTABLE ENVIRONMENT. THE BIGGEST THREAT FROM THIS AVIATION WISE
LOOKS TO BE THE POTENTIAL FOR GUSTY WINDS AND REDUCED VIS.
OTHERWISE OVERNIGHT SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DIE
OFF WITH DAYTIME HEATING AND FRONT SWEEPING ACROSS THE REGION.
THE OTHER ISSUE TONIGHT WILL BE POTENTIAL FOR FOG AND/OR LOW
STRATUS DECK. RIGHT NOW PLAN TO KEEP LOW STRATUS DECK WITH
POTENTIAL FOR AT LEAST MVFR CEILINGS OVERNIGHT INTO EARLY
TUESDAY. HIGH PRESSURE WILL RETURN TOMORROW WITH CLEARING SKIES.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...DJ
SHORT TERM...KAS
LONG TERM...KAS
AVIATION...DJ
AREA FORECAST DISCUSSION
NWS JACKSON KY
136 PM EDT MON MAY 11 2015
.UPDATE...
ISSUED AT 1050 AM EDT MON MAY 11 2015
YET ANOTHER WARM DAY IS ON TAP FOR EASTERN KENTUCKY. THE BIGGEST
QUESTION FOR TODAY WILL BE WHEN AND IF CONVECTION FIRES AHEAD OF A
BOUNDARY INCHING TOWARD THE MISSISSIPPI RIVER BASED ON THE 12Z
SURFACE ANALYSIS. EARLIER RUNS OF THE HRRR HAD A MORE PRONOUNCED
AREA OF CONVECTION AHEAD OF THE MAIN OUTFLOW DRAPED TO THE WEST.
THE MORE RECENT RUNS HAVE BACK OFF ON THIS NOTION...HOWEVER STILL
BRING AREA OF CONVECTION OUT OF THE TN VALLEY AFTER 18Z. ONE OF
THE ISSUES WILL BE LACK OF SHEAR AHEAD OF THE MAIN UPPER LEVEL
SYSTEM AND LIFTING MECHANISMS. THE SPC HAS DOWNGRADED MOST OF
EASTERN KY TO A MARGINAL RISK FOR THE TODAY. THIS SEEMS REASONABLE
GIVEN THE CURRENT FORECAST ISSUES/CONFIDENCE HEADING INTO THIS
AFTERNOON. GIVEN THE UNCERTAINTY THAT REMAINS ISOLATED DAMAGING
WIND TREAT SEEMS REASONABLE AT THIS POINT...SO WILL KEEP THAT IN
THE HWO. OTHERWISE DID UPDATED GRIDS WITH LATEST OBS AND TRENDS.
UPDATE ISSUED AT 642 AM EDT MON MAY 11 2015
UPDATED FORECAST TO REFINE THE POPS THROUGH THE DAY INCLUDING THIS
EVENING. LAST 3 RUNS OF BOTH THE HRRR AND RAP HAVE SHOWN
CONVECTIVE INITIATION ALONG THE PREFRONTAL TROUGH BETWEEN 16Z AND
18Z. ALSO BASED ON THE LOCATION...ACTIVITY LOOKS TO BLOW UP OVER
EASTERN KENTUCKY THIS AFTERNOON BEFORE ADVANCING EAST INTO THE
EARLY EVENING HOURS. WITH THESE NEW TRENDS SUPPORTED BY SEVERAL
RUNS OF THE HI RES MODELS...HAVE OPTED TO PUT THE HIGHEST POPS
BETWEEN 17Z AND 23Z THIS AFTERNOON AND EARLY EVENING. GIVEN THE
EARLIER CONVECTION...WOULD NOT EXPECT MUCH TO SPREAD ACROSS THE
AREA AFTER 00Z TONIGHT GIVEN THE ATMOSPHERE WILL BE WORKED OVER
AND THUS...LITTLE TO NO INSTABILITY TO WORK WITH. THUS...HAVE
TRIMMED BACK POPS CONSIDERABLY FOR THE TONIGHT PORTION OF THE
FORECAST. STILL APPEARS THE MAIN THREAT WITH STORMS WILL BE
DAMAGING WINDS...BUT SOME HAIL COULD ALSO OCCUR. DUE TO THE
UNIDIRECTIONAL FLOW FROM SURFACE TO 700MB...WOULD NOT EXPECT MUCH
OF A TORNADO THREAT TODAY. GIVEN THE CHANGE IN POPS...ALSO
ADJUSTED CLOUD COVER AND TEMPERATURES.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 342 AM EDT MON MAY 11 2015
UPPER LEVEL RIDGING REMAINS OVER THE EASTERN CONUS THIS MORNING
WITH TROPICAL DEPRESSION ANA MOVING NORTH ACROSS EASTERN NORTH
CAROLINA. CONVECTION OVERNIGHT ACROSS WESTERN KENTUCKY SENT A GUST
FRONT TO THE EAST WHERE IT CURRENTLY RESIDES FROM NEAR
FLEMINGSBURG...SOUTH TO SOMERSET. HOW THIS BOUNDARY MIGHT IMPACT
LATER CONVECTION IS STILL TO BE DETERMINED. ONLY SHOWERS AND
STORMS TO EVEN COME CLOSE TO THE AREA OVERNIGHT HAVE BEEN OVER
WEST VIRGINIA...FUELED BY OUTFLOW FROM STORMS YESTERDAY EVENING.
A SHORTWAVE TROUGH CONTINUES TO GENERATE ROUNDS OF SHOWERS AND
STORMS OVER THE SOUTHERN MISSISSIPPI RIVER VALLEY THIS MORNING.
THIS SHORTWAVE TROUGH WILL LIFT NORTHEAST TODAY INTO TONIGHT...
GENERATING MORE SHOWERS AND STORMS ACROSS THE OHIO RIVER VALLEY BY
THIS AFTERNOON/EVENING. BEST FORCING AND LIFT WILL RESIDE TO OUR
NORTH AND NORTHWEST THROUGH THE DAY AND EVEN TONIGHT. THIS WILL
LEAVE EASTERN KENTUCKY IN A VERY SIMILAR PATTERN THE PAST SEVERAL
DAYS WITH THE THREAT OF ISOLATED SHOWERS AND STORMS. IF THE
OUTFLOW BOUNDARY STALLS OVER THE AREA THIS MORNING...THIS MAY
SERVE AS THE FOCUS FOR SHOWERS AND STORMS TO DEVELOP LATER THIS
AFTERNOON WITH PEAK HEATING. WITH THE SHORTWAVE TROUGH FINALLY ON
THE MOVE INTO THE GREAT LAKES...A COLD FRONT WILL PUSH EAST WITH
THE GRADIENT TIGHTENING UP OVER THE AREA. THIS WILL YIELD
INCREASING WIND SHEAR AS WE HEAD THROUGH THE DAY. THUS...ANY
SHOWERS OR STORMS THAT DO MANAGE TO POP UP THIS AFTERNOON OR
EVENING WOULD HAVE THE POTENTIAL TO BECOME SEVERE. FLOW IS FAIRLY
UNIDIRECTIONAL...SO MAIN THREATS WOULD BE STRAIGHT LINE WINDS.
HAIL THREAT MAY BE THERE TOO IF INSTABILITY CAN BUILD ENOUGH PRIOR
TO STORM INITIATION...BUT FREEZING LEVELS ARE UP NEAR 12KFT
AGL...SO IT WILL TAKE SOME HEFTY UPDRAFTS TO GENERATE HAIL TODAY.
GIVEN THE SEVERE THREAT...THE AREA HAS BEEN PLACED IN A SLIGHT
RISK AREA FOR SEVERE THUNDERSTORMS BY THE SEVERE STORMS PREDICTION
CENTER.
THERE IS SOME WEAK FORCING THAT WILL PUSH ACROSS THE AREA
THIS EVENING AND HENCE THE BEST OPPORTUNITY FOR BETTER COVERAGE IN
SHOWERS AND STORMS. HOWEVER...LATEST HI-RES MODELS DO NOT SHOW
MUCH MOVING INTO THE AREA THIS EVENING...SO CONFIDENCE IS FAIRLY
LOW ON CONVECTION THIS EVENING AS OF RIGHT NOW. THUS...WILL STAY
WITH THE CHANCE POPS WITH THE PREVIOUS FORECAST. IF CONVECTION
FORMS...IT SHOULD BE ON THE WAY OUT BY MIDNIGHT...WITH SUBSIDENCE
BUILDING BEHIND THE DEPARTING STORMS. THE COLD FRONT WILL LAG WELL
BEHIND THE CONVECTION AND WILL NOT MAKE ITS MOVE ACROSS THE AREA
UNTIL TUESDAY MORNING...WHEN ANOTHER ISOLATED SHOWER MAY BE
POSSIBLE. IF THE FRONT HANGS UP TOO MUCH ON TUESDAY...MAY NEED TO
WATCH POTENTIAL FOR A FEW STORMS TO FIRE UP ON THE BOUNDARY AS IT
SLIPS ACROSS THE AREA. AS IT STANDS NOW...IT SHOULD MOVE THROUGH
IN TIME TO PREVENT THIS FROM HAPPENING. TUESDAY WILL BE COOLER
WITH DRIER AIR ADVECTING INTO THE AREA...THIS WILL MAKE FOR A
PLEASANT AFTERNOON.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 342 AM EDT MON MAY 11 2015
THE EXTENDED FORECAST PERIOD BEGINS ON TUESDAY NIGHT WITH UPPER
LEVEL RIDGING OVER THE REGION KEEPING EASTERN KENTUCKY DRY THROUGH
THE WEDNESDAY AND MUCH OF THURSDAY TIME PERIOD. THIS PATTERN SEEMS
TO TAKE A CHANGE AS THE PATTERN BECOMES MORE ACTIVE AND A STRONG
SHORTWAVE MOVES OUT OF THE SOUTHWESTERN CONUS AND TRAVELS OVER THE
RIDGE AND INTO THE UPPER PLAINS AND GREAT LAKES BY FRIDAY. THIS NOT
ONLY BRINGS SOME UPPER LEVEL SUPPORT INTO THE OH VALLEYS REGION BUT
ALSO OPENS THE GULF AS SOME MID LEVEL MOISTURE ADVECTS INTO THE
REGION. ALSO DURING THIS TIME ON FRIDAY...A STRONG CLOSED LOW COMES
ASHORE IN SOUTHERN CA. THIS FEATURE STANDS TO BRING A GOOD SHOT OF
UPPER LEVEL ENERGY TO THE PLAINS AND EVEN INTO THE MIDWEST BY
SUNDAY. THE EURO AND GFS ARE SIMILAR IN THIS TREND.
CLOSER TO THE SURFACE...THE APPROACH OF THE FIRST MENTIONED
SHORTWAVE WILL BRING INCREASED SOUTHERLY LOW LEVEL FLOW INTO THE
AREA AND AS THE RIDGE WEAKENS...CONVECTION WILL BECOME MORE AND MORE
PREVALENT...ESPECIALLY BY FRIDAY. A BOUNDARY SHOULD BEGIN TO FORM
TO THE NORTH OF THE OH RIVER WITH PLENTY OF CONVECTION BY FRIDAY
AFTERNOON AND AS WELL INTO THE WEEKEND. THIS LEAVES EASTERN
KENTUCKY IN A WARM...HUMID...AND UNSTABLE PATTERN WITH DIURNALLY
DRIVEN CONVECTION. BY SUNDAY HOWEVER...THE MENTIONED STRONG LOW
THAT CAME ASHORE OVER SOCA WILL MOVE INTO THE UPPER MIDWEST
DRAGGING A POTENT COLD FRONT TO THE OH VALLEY DOORSTEP.
THE EURO AND GFS DO SHOW SOME CONSISTENCY HERE. THE SUPER BLEND DID
COME IN RATHER HIGH IN POPS...ESPECIALLY FOR FRIDAY. TRENDS OF THE
RIDGE MIGHT BE ENOUGH TO SUPPRESS CONVECTION ENOUGH THAT LIKELY POPS
SEEM A BIT...UNLIKELY...AND SO LOWERED THEM DURING THIS TIME FRAME
AS WELL. ALSO THE BLEND HAD NO INDICATION OF ANY SORT OF DIURNALLY
TREND TO THE CONVECTION AND GIVEN WHAT THE AREA HAS EXPERIENCED THIS
PAST WEEK...THIS SEEMS TO BE A REPEAT OF SORTS. DID THEN ADDRESS
THIS WITH THE NEIGHBORING OFFICES AND MADE THESE ADJUSTMENTS TO THE
POPS INHERITED BY THE SUPER BLEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 133 PM EDT MON MAY 11 2015
THIS AFTERNOON WE HAVE SEEN CONVECTION FIRE UP ACROSS PORTIONS OF
EASTERN KY. THESE ISOLATED TO SCATTER STORMS WILL BE THE BIGGEST
CONCERN FOR THE NEXT FEW HOURS. IT DOES LOOK LIKE THERE COULD BE
TWO ROUND...ONE ONGOING CONVECTION MORE DIURNALLY DRIVEN UNDER
MODERATELY UNSTABLE ENVIRONMENT...TWO THE COLD FRONT AND ANY
OUTFLOWS AHEAD OF THE FRONT. THE SECOND LINE IS IN QUESTION GIVEN
THAT STORMS HAVE ALREADY FIRED AND COULD TAP OUT THE CURRENT
UNSTABLE ENVIRONMENT. THE BIGGEST THREAT FROM THIS AVIATION WISE
LOOKS TO BE THE POTENTIAL FOR GUSTY WINDS AND REDUCED VIS.
OTHERWISE OVERNIGHT SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DIE
OFF WITH DAYTIME HEATING AND FRONT SWEEPING ACROSS THE REGION.
THE OTHER ISSUE TONIGHT WILL BE POTENTIAL FOR FOG AND/OR LOW
STRATUS DECK. RIGHT NOW PLAN TO KEEP LOW STRATUS DECK WITH
POTENTIAL FOR AT LEAST MVFR CEILINGS OVERNIGHT INTO EARLY
TUESDAY. HIGH PRESSURE WILL RETURN TOMORROW WITH CLEARING SKIES.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...DJ
SHORT TERM...KAS
LONG TERM...KAS
AVIATION...DJ
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1203 PM CDT MON MAY 11 2015
.UPDATE...
ISSUED AT 1200 PM CDT MON MAY 11 2015
QUICK UPDATE TO REFLECT SHORT TERM TRENDS THIS AFTERNOON WITH
RESPECT TO CONVECTIVE ACTIVITY AND SENSIBLE WEATHER ELEMENTS. ANY
LOCALIZED BREAKS IN THE CLOUD COVER MAY CAUSE SLIGHT ELEVATION IN
TEMPERATURES BY 1-3 DEGREES ABOVE CURRENT FORECAST.
ANTICIPATE MOST OF THE CONVECTION THIS AFTERNOON MAY REMAIN
SOMEWHAT ELEVATED WITH THE APPROACHING FRONT, THE FRONTAL LOCATION
SUGGESTED BY THE FINE LINE ON THE KLSX RADAR ALONG AND EAST OF
THE MISSISSIPPI RIVER. SPC MARGINAL RISK FOR SEVERE STORMS SEEMS
SOMEWHAT OPTIMISTIC, BUT THE POTENTIAL FOR SOME SURFACE-BASED
CONVECTION WILL STILL REMAIN POSSIBLE OVER THE EASTERN PARTS OF
SOUTHWEST INDIANA AND THE PENNYRILE REGION OF WEST KENTUCKY
BETWEEN NOON AND 5 PM.
ISSUED A SPECIAL WEATHER STATEMENT FOR GUSTY WINDS AHEAD OF THE
FRONT IN SOUTHWEST INDIANA AND WEST KENTUCKY OUTSIDE OF CONVECTION
THIS AFTERNOON...MAINLY FOR BOATERS AND TRAVELERS ON THE ROAD.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 343 AM CDT MON MAY 11 2015
THE LARGE AREA OF CONVECTION THAT HAS BEEN ADVERTISED FOR
DAYS...HAS DEVELOPED RIGHT ON SCHEDULE EARLY THIS MORNING ACROSS
SOUTHEAST MISSOURI. THE PREPONDERANCE OF SHORT TERM GUIDANCE LIFTS
THE BAND NORTH NORTHEAST THROUGH SOUTHEAST MISSOURI AND SOUTHERN
ILLINOIS THROUGH THE MORNING HOURS...WITH THE TAIL END OF IT
DISSIPATING AS IT MOVES EAST THROUGH WEST KENTUCKY AND SOUTHWEST
INDIANA. THIS LARGE AREA OF CONVECTION SEEMS TO BE ASSOCIATED
WITH AN UPPER-LEVEL JET LIFTING NORTHWARD OUT OF THE AREA BY THIS
AFTERNOON.
THE BIG QUESTION IS WHAT WILL HAPPEN THIS AFTERNOON OVER WEST
KENTUCKY AND SOUTHWEST INDIANA. IT LOOKS LIKE SCATTERED CONVECTION
AT BEST...AS THE 06Z HRRR HAS NEXT TO NOTHING LEFT IN THE EAST
AFTER 17Z. THE POPS WITH THIS FORECAST PACKAGE ARE LIKELY TOO
WET IN THE EAST THIS AFTERNOON.
AS FOR SEVERE...WILL KEEP AN EYE ON RADAR THROUGH DAYBREAK...BUT
IT APPEARS THAT THERE ARE JUST TOO MANY UPDRAFTS FOR ANY ONE OF
THEM TO GET CLOSE TO SEVERE LEVELS. HAVE NOT SEEN ANYTHING SO FAR
THAT WAS ORIENTED IN SUCH A WAY AS TO CATCH THE ENVIRONMENTAL
WINDS...AND NOT SURE IF THE STRONGER WINDS WOULD REACH THE GROUND
GIVEN THE ELEVATED NATURE OF THE STORMS.
ANY STORM THAT GETS GOING IN THE EAST THIS AFTERNOON WOULD HAVE
SOME POTENTIAL TO BE SEVERE...BUT WIND FIELDS ARE STILL A BIT
SUSPECT...WITH MODEL SOUNDINGS INDICATING BACKING WINDS WITH
HEIGHT IN THE LOW-LEVELS. OF COURSE...WITH THE POTENTIAL FOR
CONVECTIVE DEVELOPMENT IN DOUBT THIS AFTERNOON...THE SEVERE
PROBABILITIES ARE RATHER LOW. BETTER CHANCES FOR SEVERE WOULD
SEEM TO BE EAST AND NORTHEAST OF OUR AREA.
IT STILL LOOKS LIKE THE CONVECTION WILL BE WELL EAST OF THE AREA
BY 00Z TUESDAY...AND THE REMAINDER OF THE SHORT TERM WILL BE
DRY WITH SURFACE HIGH PRESSURE DOMINATING THE REGION. CONSIDERED
INSERTING A SLIGHT CHANCE POP WEDNESDAY NIGHT IN THE FAR
WEST...BUT A GFS SOUNDING FROM THAT AREA WAS UNINSPIRING.
SOUTHWEST WINDS FROM MID-MORNING THROUGH MID AFTERNOON ARE
FORECAST TO BE AT OR ABOVE LAKE WIND ADVISORY CRITERIA OVER THE
EASTERN HALF OF THE AREA. HOWEVER...CONFIDENCE IN THE CONVECTIVE
EVOLUTION CASTS SOME DOUBT ON THE WIND FORECAST...SO WILL NOT
ISSUE AN ADVISORY AT THIS TIME. WILL LET THE DAY SHIFT MONITOR
TRENDS THIS MORNING AND ISSUE IF/WHEN IT BECOMES MORE OBVIOUS.
WEST NORTHWEST WINDS OVER THE NORTHERN HALF OF THE AREA WILL BE
NEAR CRITERIA ON TUESDAY AS WELL.
GENERALLY STAYED CLOSE TO THE CONSENSUS OF GUIDANCE FOR TEMPERATURES
THROUGH THE PERIOD. MAY NOT BE COLD ENOUGH TUESDAY NIGHT...WITH
DECENT RADIATIONAL COOLING REGIME AND DRY AIR IN PLACE.
.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 343 AM CDT MON MAY 11 2015
ON THE LARGER SCALE...OPERATIONAL MODELS AND THEIR ENSEMBLES ARE IN
RELATIVELY GOOD AGREEMENT THROUGH THE EXTENDED PERIOD. HOWEVER...
MUCH OF THE WEATHER DURING THIS TIME WILL BE DRIVEN BY SUBTLE
MESOSCALE FEATURES THAT RESULT IN RELATIVELY WEAK FORCING. AS A
RESULT...OUR CONFIDENCE IS ONLY AVERAGE AT BEST DURING THIS TIME.
THE UPPER LEVEL PATTERN THROUGH THE WEEKEND WILL BE DOMINATED BY A
RIDGE POSITIONED FROM THE GULF COAST NORTHWARD ACROSS THE EASTERN
HALF OF THE NATION. A LARGE UPPER LEVEL LOW OVER THE EASTERN PACIFIC
IS FORECAST TO SLOWLY MIGRATE EAST INTO THE INTERMOUNTAIN WEST LATE
IN THE WEEK...REACHING THE PLAINS LATE IN THE WEEKEND.
AS FOR THE DETAILS...HIGH PRESSURE WILL SHIFT EAST OF THE REGION BY
THURSDAY. AN UPPER LEVEL DISTURBANCE IS FORECAST TO TRACK ACROSS THE
MIDDLE AND UPPER MISSISSIPPI RIVER VALLEYS AS A WARM FRONT LIFTS
NORTH ACROSS THE REGION THURSDAY AND THURSDAY NIGHT. THE RESULTANT
INCREASE IN MOISTURE AND INSTABILITY WILL LEAD TO OUR NEXT CHANCE OF
SHOWERS AND THUNDERSTORMS DURING THIS TIME.
BY FRIDAY AND SATURDAY...THE UPPER LEVEL RIDGE BECOMES THE DOMINANT
WEATHER FEATURE. HOWEVER...RATHER WARM AND HUMID CONDITIONS WILL
PREVAIL BENEATH THIS RIDGE. EVEN THOUGH ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS CERTAINLY CANNOT BE RULED OUT...FORECAST
MODELS APPEAR TO BE OVERDONE WITH RESPECT TO PRECIPITATION CHANCES
AND COVERAGE. AS A RESULT...WE COLLABORATED WITH SURROUNDING OFFICES
TO REDUCE RAIN CHANCES TO NO HIGHER THAN 30-40 PERCENT DURING THIS
TIME. RAIN CHANCES SHOULD INCREASE LATE IN THE WEEKEND AS THE
REMNANTS OF THE UPPER LOW DRAW CLOSER.
TEMPERATURES WILL UNDERGO A SLOW WARMING TREND THROUGH THE PERIOD.
HIGHS WILL START OFF IN THE MID TO UPPER 70S ON THURSDAY...THEN
MODERATE INTO THE LOWER AND PERHAPS MID 80S BY THE WEEKEND. LOWS OF
50 TO 55 THURSDAY MORNING WILL RISE INTO THE LOWER AND MID 60S
DURING THE REMAINDER OF THE PERIOD.
&&
.AVIATION...
ISSUED AT 653 AM CDT MON MAY 11 2015
BAND OF RAIN AND EMBEDDED THUNDERSTORMS IS EXPECTED TO DISSIPATE
OR BECOME MORE SCATTERED AS IT MOVES SLOWLY EAST THROUGH 18Z. A
PERIOD OF MVFR CONDITIONS IS POSSIBLE AS THE PRECIPITATION MOVES
THROUGH EACH SITE. CONFINED THE TS AND MVFR CONDITIONS TO A 2 HOUR
PERIOD. SOME LOW VFR CEILINGS ARE LIKELY FOR A FEW HOURS BEHIND
THE RAIN...AND MVFR CEILINGS CANNOT BE RULED OUT.
SOUTH WINDS WILL INCREASE AND VEER TO WEST SOUTHWEST THROUGH THE
DAY. SUSTAINED WINDS IN THE TEENS AND GUSTS WELL INTO THE 20S ARE
EXPECTED...WITH THE STRONGEST WINDS AT KOWB. SKIES WILL CLEAR
QUICKLY EARLY THIS EVENING...AND WINDS WILL SUBSIDE TO UNDER 10KTS
WITH SUNSET.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...SMITH
SHORT TERM...DRS
LONG TERM...RJP
AVIATION...DRS
AREA FORECAST DISCUSSION
NWS PADUCAH KY
654 AM CDT MON MAY 11 2015
.UPDATE...
ISSUED AT 653 AM CDT MON MAY 11 2015
THE AVIATION SECTION HAS BEEN UPDATED FOR THE 12Z TAF ISSUANCE.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 343 AM CDT MON MAY 11 2015
THE LARGE AREA OF CONVECTION THAT HAS BEEN ADVERTISED FOR
DAYS...HAS DEVELOPED RIGHT ON SCHEDULE EARLY THIS MORNING ACROSS
SOUTHEAST MISSOURI. THE PREPONDERANCE OF SHORT TERM GUIDANCE LIFTS
THE BAND NORTH NORTHEAST THROUGH SOUTHEAST MISSOURI AND SOUTHERN
ILLINOIS THROUGH THE MORNING HOURS...WITH THE TAIL END OF IT
DISSIPATING AS IT MOVES EAST THROUGH WEST KENTUCKY AND SOUTHWEST
INDIANA. THIS LARGE AREA OF CONVECTION SEEMS TO BE ASSOCIATED
WITH AN UPPER-LEVEL JET LIFTING NORTHWARD OUT OF THE AREA BY THIS
AFTERNOON.
THE BIG QUESTION IS WHAT WILL HAPPEN THIS AFTERNOON OVER WEST
KENTUCKY AND SOUTHWEST INDIANA. IT LOOKS LIKE SCATTERED CONVECTION
AT BEST...AS THE 06Z HRRR HAS NEXT TO NOTHING LEFT IN THE EAST
AFTER 17Z. THE POPS WITH THIS FORECAST PACKAGE ARE LIKELY TOO
WET IN THE EAST THIS AFTERNOON.
AS FOR SEVERE...WILL KEEP AN EYE ON RADAR THROUGH DAYBREAK...BUT
IT APPEARS THAT THERE ARE JUST TOO MANY UPDRAFTS FOR ANY ONE OF
THEM TO GET CLOSE TO SEVERE LEVELS. HAVE NOT SEEN ANYTHING SO FAR
THAT WAS ORIENTED IN SUCH A WAY AS TO CATCH THE ENVIRONMENTAL
WINDS...AND NOT SURE IF THE STRONGER WINDS WOULD REACH THE GROUND
GIVEN THE ELEVATED NATURE OF THE STORMS.
ANY STORM THAT GETS GOING IN THE EAST THIS AFTERNOON WOULD HAVE
SOME POTENTIAL TO BE SEVERE...BUT WIND FIELDS ARE STILL A BIT
SUSPECT...WITH MODEL SOUNDINGS INDICATING BACKING WINDS WITH
HEIGHT IN THE LOW-LEVELS. OF COURSE...WITH THE POTENTIAL FOR
CONVECTIVE DEVELOPMENT IN DOUBT THIS AFTERNOON...THE SEVERE
PROBABILITIES ARE RATHER LOW. BETTER CHANCES FOR SEVERE WOULD
SEEM TO BE EAST AND NORTHEAST OF OUR AREA.
IT STILL LOOKS LIKE THE CONVECTION WILL BE WELL EAST OF THE AREA
BY 00Z TUESDAY...AND THE REMAINDER OF THE SHORT TERM WILL BE
DRY WITH SURFACE HIGH PRESSURE DOMINATING THE REGION. CONSIDERED
INSERTING A SLIGHT CHANCE POP WEDNESDAY NIGHT IN THE FAR
WEST...BUT A GFS SOUNDING FROM THAT AREA WAS UNINSPIRING.
SOUTHWEST WINDS FROM MID-MORNING THROUGH MID AFTERNOON ARE
FORECAST TO BE AT OR ABOVE LAKE WIND ADVISORY CRITERIA OVER THE
EASTERN HALF OF THE AREA. HOWEVER...CONFIDENCE IN THE CONVECTIVE
EVOLUTION CASTS SOME DOUBT ON THE WIND FORECAST...SO WILL NOT
ISSUE AN ADVISORY AT THIS TIME. WILL LET THE DAY SHIFT MONITOR
TRENDS THIS MORNING AND ISSUE IF/WHEN IT BECOMES MORE OBVIOUS.
WEST NORTHWEST WINDS OVER THE NORTHERN HALF OF THE AREA WILL BE
NEAR CRITERIA ON TUESDAY AS WELL.
GENERALLY STAYED CLOSE TO THE CONSENSUS OF GUIDANCE FOR TEMPERATURES
THROUGH THE PERIOD. MAY NOT BE COLD ENOUGH TUESDAY NIGHT...WITH
DECENT RADIATIONAL COOLING REGIME AND DRY AIR IN PLACE.
.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 343 AM CDT MON MAY 11 2015
ON THE LARGER SCALE...OPERATIONAL MODELS AND THEIR ENSEMBLES ARE IN
RELATIVELY GOOD AGREEMENT THROUGH THE EXTENDED PERIOD. HOWEVER...
MUCH OF THE WEATHER DURING THIS TIME WILL BE DRIVEN BY SUBTLE
MESOSCALE FEATURES THAT RESULT IN RELATIVELY WEAK FORCING. AS A
RESULT...OUR CONFIDENCE IS ONLY AVERAGE AT BEST DURING THIS TIME.
THE UPPER LEVEL PATTERN THROUGH THE WEEKEND WILL BE DOMINATED BY A
RIDGE POSITIONED FROM THE GULF COAST NORTHWARD ACROSS THE EASTERN
HALF OF THE NATION. A LARGE UPPER LEVEL LOW OVER THE EASTERN PACIFIC
IS FORECAST TO SLOWLY MIGRATE EAST INTO THE INTERMOUNTAIN WEST LATE
IN THE WEEK...REACHING THE PLAINS LATE IN THE WEEKEND.
AS FOR THE DETAILS...HIGH PRESSURE WILL SHIFT EAST OF THE REGION BY
THURSDAY. AN UPPER LEVEL DISTURBANCE IS FORECAST TO TRACK ACROSS THE
MIDDLE AND UPPER MISSISSIPPI RIVER VALLEYS AS A WARM FRONT LIFTS
NORTH ACROSS THE REGION THURSDAY AND THURSDAY NIGHT. THE RESULTANT
INCREASE IN MOISTURE AND INSTABILITY WILL LEAD TO OUR NEXT CHANCE OF
SHOWERS AND THUNDERSTORMS DURING THIS TIME.
BY FRIDAY AND SATURDAY...THE UPPER LEVEL RIDGE BECOMES THE DOMINANT
WEATHER FEATURE. HOWEVER...RATHER WARM AND HUMID CONDITIONS WILL
PREVAIL BENEATH THIS RIDGE. EVEN THOUGH ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS CERTAINLY CANNOT BE RULED OUT...FORECAST
MODELS APPEAR TO BE OVERDONE WITH RESPECT TO PRECIPITATION CHANCES
AND COVERAGE. AS A RESULT...WE COLLABORATED WITH SURROUNDING OFFICES
TO REDUCE RAIN CHANCES TO NO HIGHER THAN 30-40 PERCENT DURING THIS
TIME. RAIN CHANCES SHOULD INCREASE LATE IN THE WEEKEND AS THE
REMNANTS OF THE UPPER LOW DRAW CLOSER.
TEMPERATURES WILL UNDERGO A SLOW WARMING TREND THROUGH THE PERIOD.
HIGHS WILL START OFF IN THE MID TO UPPER 70S ON THURSDAY...THEN
MODERATE INTO THE LOWER AND PERHAPS MID 80S BY THE WEEKEND. LOWS OF
50 TO 55 THURSDAY MORNING WILL RISE INTO THE LOWER AND MID 60S
DURING THE REMAINDER OF THE PERIOD.
&&
.AVIATION...
ISSUED AT 653 AM CDT MON MAY 11 2015
BAND OF RAIN AND EMBEDDED THUNDERSTORMS IS EXPECTED TO DISSIPATE
OR BECOME MORE SCATTERED AS IT MOVES SLOWLY EAST THROUGH 18Z. A
PERIOD OF MVFR CONDITIONS IS POSSIBLE AS THE PRECIPITATION MOVES
THROUGH EACH SITE. CONFINED THE TS AND MVFR CONDITIONS TO A 2 HOUR
PERIOD. SOME LOW VFR CEILINGS ARE LIKELY FOR A FEW HOURS BEHIND
THE RAIN...AND MVFR CEILINGS CANNOT BE RULED OUT.
SOUTH WINDS WILL INCREASE AND VEER TO WEST SOUTHWEST THROUGH THE
DAY. SUSTAINED WINDS IN THE TEENS AND GUSTS WELL INTO THE 20S ARE
EXPECTED...WITH THE STRONGEST WINDS AT KOWB. SKIES WILL CLEAR
QUICKLY EARLY THIS EVENING...AND WINDS WILL SUBSIDE TO UNDER 10KTS
WITH SUNSET.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...DRS
SHORT TERM...DRS
LONG TERM...RJP
AVIATION...DRS
AREA FORECAST DISCUSSION
NWS JACKSON KY
642 AM EDT MON MAY 11 2015
.UPDATE...
ISSUED AT 642 AM EDT MON MAY 11 2015
UPDATED FORECAST TO REFINE THE POPS THROUGH THE DAY INCLUDING THIS
EVENING. LAST 3 RUNS OF BOTH THE HRRR AND RAP HAVE SHOWN
CONVECTIVE INITIATION ALONG THE PREFRONTAL TROUGH BETWEEN 16Z AND
18Z. ALSO BASED ON THE LOCATION...ACTIVITY LOOKS TO BLOW UP OVER
EASTERN KENTUCKY THIS AFTERNOON BEFORE ADVANCING EAST INTO THE
EARLY EVENING HOURS. WITH THESE NEW TRENDS SUPPORTED BY SEVERAL
RUNS OF THE HI RES MODELS...HAVE OPTED TO PUT THE HIGHEST POPS
BETWEEN 17Z AND 23Z THIS AFTERNOON AND EARLY EVENING. GIVEN THE
EARLIER CONVECTION...WOULD NOT EXPECT MUCH TO SPREAD ACROSS THE
AREA AFTER 00Z TONIGHT GIVEN THE ATMOSPHERE WILL BE WORKED OVER
AND THUS...LITTLE TO NO INSTABILITY TO WORK WITH. THUS...HAVE
TRIMMED BACK POPS CONSIDERABLY FOR THE TONIGHT PORTION OF THE
FORECAST. STILL APPEARS THE MAIN THREAT WITH STORMS WILL BE
DAMAGING WINDS...BUT SOME HAIL COULD ALSO OCCUR. DUE TO THE
UNIDIRECTIONAL FLOW FROM SURFACE TO 700MB...WOULD NOT EXPECT MUCH
OF A TORNADO THREAT TODAY. GIVEN THE CHANGE IN POPS...ALSO
ADJUSTED CLOUD COVER AND TEMPERATURES.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 342 AM EDT MON MAY 11 2015
UPPER LEVEL RIDGING REMAINS OVER THE EASTERN CONUS THIS MORNING
WITH TROPICAL DEPRESSION ANA MOVING NORTH ACROSS EASTERN NORTH
CAROLINA. CONVECTION OVERNIGHT ACROSS WESTERN KENTUCKY SENT A GUST
FRONT TO THE EAST WHERE IT CURRENTLY RESIDES FROM NEAR
FLEMINGSBURG...SOUTH TO SOMERSET. HOW THIS BOUNDARY MIGHT IMPACT
LATER CONVECTION IS STILL TO BE DETERMINED. ONLY SHOWERS AND
STORMS TO EVEN COME CLOSE TO THE AREA OVERNIGHT HAVE BEEN OVER
WEST VIRGINIA...FUELED BY OUTFLOW FROM STORMS YESTERDAY EVENING.
A SHORTWAVE TROUGH CONTINUES TO GENERATE ROUNDS OF SHOWERS AND
STORMS OVER THE SOUTHERN MISSISSIPPI RIVER VALLEY THIS MORNING.
THIS SHORTWAVE TROUGH WILL LIFT NORTHEAST TODAY INTO TONIGHT...
GENERATING MORE SHOWERS AND STORMS ACROSS THE OHIO RIVER VALLEY BY
THIS AFTERNOON/EVENING. BEST FORCING AND LIFT WILL RESIDE TO OUR
NORTH AND NORTHWEST THROUGH THE DAY AND EVEN TONIGHT. THIS WILL
LEAVE EASTERN KENTUCKY IN A VERY SIMILAR PATTERN THE PAST SEVERAL
DAYS WITH THE THREAT OF ISOLATED SHOWERS AND STORMS. IF THE
OUTFLOW BOUNDARY STALLS OVER THE AREA THIS MORNING...THIS MAY
SERVE AS THE FOCUS FOR SHOWERS AND STORMS TO DEVELOP LATER THIS
AFTERNOON WITH PEAK HEATING. WITH THE SHORTWAVE TROUGH FINALLY ON
THE MOVE INTO THE GREAT LAKES...A COLD FRONT WILL PUSH EAST WITH
THE GRADIENT TIGHTENING UP OVER THE AREA. THIS WILL YIELD
INCREASING WIND SHEAR AS WE HEAD THROUGH THE DAY. THUS...ANY
SHOWERS OR STORMS THAT DO MANAGE TO POP UP THIS AFTERNOON OR
EVENING WOULD HAVE THE POTENTIAL TO BECOME SEVERE. FLOW IS FAIRLY
UNIDIRECTIONAL...SO MAIN THREATS WOULD BE STRAIGHT LINE WINDS.
HAIL THREAT MAY BE THERE TOO IF INSTABILITY CAN BUILD ENOUGH PRIOR
TO STORM INITIATION...BUT FREEZING LEVELS ARE UP NEAR 12KFT
AGL...SO IT WILL TAKE SOME HEFTY UPDRAFTS TO GENERATE HAIL TODAY.
GIVEN THE SEVERE THREAT...THE AREA HAS BEEN PLACED IN A SLIGHT
RISK AREA FOR SEVERE THUNDERSTORMS BY THE SEVERE STORMS PREDICTION
CENTER.
THERE IS SOME WEAK FORCING THAT WILL PUSH ACROSS THE AREA
THIS EVENING AND HENCE THE BEST OPPORTUNITY FOR BETTER COVERAGE IN
SHOWERS AND STORMS. HOWEVER...LATEST HI-RES MODELS DO NOT SHOW
MUCH MOVING INTO THE AREA THIS EVENING...SO CONFIDENCE IS FAIRLY
LOW ON CONVECTION THIS EVENING AS OF RIGHT NOW. THUS...WILL STAY
WITH THE CHANCE POPS WITH THE PREVIOUS FORECAST. IF CONVECTION
FORMS...IT SHOULD BE ON THE WAY OUT BY MIDNIGHT...WITH SUBSIDENCE
BUILDING BEHIND THE DEPARTING STORMS. THE COLD FRONT WILL LAG WELL
BEHIND THE CONVECTION AND WILL NOT MAKE ITS MOVE ACROSS THE AREA
UNTIL TUESDAY MORNING...WHEN ANOTHER ISOLATED SHOWER MAY BE
POSSIBLE. IF THE FRONT HANGS UP TOO MUCH ON TUESDAY...MAY NEED TO
WATCH POTENTIAL FOR A FEW STORMS TO FIRE UP ON THE BOUNDARY AS IT
SLIPS ACROSS THE AREA. AS IT STANDS NOW...IT SHOULD MOVE THROUGH
IN TIME TO PREVENT THIS FROM HAPPENING. TUESDAY WILL BE COOLER
WITH DRIER AIR ADVECTING INTO THE AREA...THIS WILL MAKE FOR A
PLEASANT AFTERNOON.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 342 AM EDT MON MAY 11 2015
THE EXTENDED FORECAST PERIOD BEGINS ON TUESDAY NIGHT WITH UPPER
LEVEL RIDGING OVER THE REGION KEEPING EASTERN KENTUCKY DRY THROUGH
THE WEDNESDAY AND MUCH OF THURSDAY TIME PERIOD. THIS PATTERN SEEMS
TO TAKE A CHANGE AS THE PATTERN BECOMES MORE ACTIVE AND A STRONG
SHORTWAVE MOVES OUT OF THE SOUTHWESTERN CONUS AND TRAVELS OVER THE
RIDGE AND INTO THE UPPER PLAINS AND GREAT LAKES BY FRIDAY. THIS NOT
ONLY BRINGS SOME UPPER LEVEL SUPPORT INTO THE OH VALLEYS REGION BUT
ALSO OPENS THE GULF AS SOME MID LEVEL MOISTURE ADVECTS INTO THE
REGION. ALSO DURING THIS TIME ON FRIDAY...A STRONG CLOSED LOW COMES
ASHORE IN SOUTHERN CA. THIS FEATURE STANDS TO BRING A GOOD SHOT OF
UPPER LEVEL ENERGY TO THE PLAINS AND EVEN INTO THE MIDWEST BY
SUNDAY. THE EURO AND GFS ARE SIMILAR IN THIS TREND.
CLOSER TO THE SURFACE...THE APPROACH OF THE FIRST MENTIONED
SHORTWAVE WILL BRING INCREASED SOUTHERLY LOW LEVEL FLOW INTO THE
AREA AND AS THE RIDGE WEAKENS...CONVECTION WILL BECOME MORE AND MORE
PREVALENT...ESPECIALLY BY FRIDAY. A BOUNDARY SHOULD BEGIN TO FORM
TO THE NORTH OF THE OH RIVER WITH PLENTY OF CONVECTION BY FRIDAY
AFTERNOON AND AS WELL INTO THE WEEKEND. THIS LEAVES EASTERN
KENTUCKY IN A WARM...HUMID...AND UNSTABLE PATTERN WITH DIURNALLY
DRIVEN CONVECTION. BY SUNDAY HOWEVER...THE MENTIONED STRONG LOW
THAT CAME ASHORE OVER SOCA WILL MOVE INTO THE UPPER MIDWEST
DRAGGING A POTENT COLD FRONT TO THE OH VALLEY DOORSTEP.
THE EURO AND GFS DO SHOW SOME CONSISTENCY HERE. THE SUPER BLEND DID
COME IN RATHER HIGH IN POPS...ESPECIALLY FOR FRIDAY. TRENDS OF THE
RIDGE MIGHT BE ENOUGH TO SUPPRESS CONVECTION ENOUGH THAT LIKELY POPS
SEEM A BIT...UNLIKELY...AND SO LOWERED THEM DURING THIS TIME FRAME
AS WELL. ALSO THE BLEND HAD NO INDICATION OF ANY SORT OF DIURNALLY
TREND TO THE CONVECTION AND GIVEN WHAT THE AREA HAS EXPERIENCED THIS
PAST WEEK...THIS SEEMS TO BE A REPEAT OF SORTS. DID THEN ADDRESS
THIS WITH THE NEIGHBORING OFFICES AND MADE THESE ADJUSTMENTS TO THE
POPS INHERITED BY THE SUPER BLEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 642 AM EDT MON MAY 11 2015
VFR CONDITIONS WILL BE SEEN TO START THE FORECAST PERIOD.
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ARE NOW EXPECTED
TO DEVELOP BETWEEN 16Z AND 23Z...WHICH IS AN EARLIER ONSET THAN
PREVIOUSLY EXPECTED. THIS NEW TIMING WILL BE REFLECTED IN THE 12Z
TAFS. AS MENTIONED BEFORE...GUSTY WINDS ARE EXPECTED IN AND AROUND
ANY THUNDERSTORMS THIS AFTERNOON ALONG WITH THE THREAT OF
TURBULENCE. VFR CONDITIONS SHOULD DOMINATE THOUGH...BUT SOME
REDUCED VISIBILITIES ARE POSSIBLE IN THE STRONGER STORMS. VFR
CONDITIONS WILL RETURN BY LATE EVENING...BUT WILL NEED TO WATCH
FOR FOG OR LOW CLOUD DEVELOPMENT PENDING RAINFALL AMOUNTS AND
WHERE THE RAIN FALLS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...KAS
LONG TERM...KAS
AVIATION...KAS
AREA FORECAST DISCUSSION
NWS PADUCAH KY
343 AM CDT MON MAY 11 2015
.SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 343 AM CDT MON MAY 11 2015
THE LARGE AREA OF CONVECTION THAT HAS BEEN ADVERTISED FOR
DAYS...HAS DEVELOPED RIGHT ON SCHEDULE EARLY THIS MORNING ACROSS
SOUTHEAST MISSOURI. THE PREPONDERANCE OF SHORT TERM GUIDANCE LIFTS
THE BAND NORTH NORTHEAST THROUGH SOUTHEAST MISSOURI AND SOUTHERN
ILLINOIS THROUGH THE MORNING HOURS...WITH THE TAIL END OF IT
DISSIPATING AS IT MOVES EAST THROUGH WEST KENTUCKY AND SOUTHWEST
INDIANA. THIS LARGE AREA OF CONVECTION SEEMS TO BE ASSOCIATED
WITH AN UPPER-LEVEL JET LIFTING NORTHWARD OUT OF THE AREA BY THIS
AFTERNOON.
THE BIG QUESTION IS WHAT WILL HAPPEN THIS AFTERNOON OVER WEST
KENTUCKY AND SOUTHWEST INDIANA. IT LOOKS LIKE SCATTERED CONVECTION
AT BEST...AS THE 06Z HRRR HAS NEXT TO NOTHING LEFT IN THE EAST
AFTER 17Z. THE POPS WITH THIS FORECAST PACKAGE ARE LIKELY TOO
WET IN THE EAST THIS AFTERNOON.
AS FOR SEVERE...WILL KEEP AN EYE ON RADAR THROUGH DAYBREAK...BUT
IT APPEARS THAT THERE ARE JUST TOO MANY UPDRAFTS FOR ANY ONE OF
THEM TO GET CLOSE TO SEVERE LEVELS. HAVE NOT SEEN ANYTHING SO FAR
THAT WAS ORIENTED IN SUCH A WAY AS TO CATCH THE ENVIRONMENTAL
WINDS...AND NOT SURE IF THE STRONGER WINDS WOULD REACH THE GROUND
GIVEN THE ELEVATED NATURE OF THE STORMS.
ANY STORM THAT GETS GOING IN THE EAST THIS AFTERNOON WOULD HAVE
SOME POTENTIAL TO BE SEVERE...BUT WIND FIELDS ARE STILL A BIT
SUSPECT...WITH MODEL SOUNDINGS INDICATING BACKING WINDS WITH
HEIGHT IN THE LOW-LEVELS. OF COURSE...WITH THE POTENTIAL FOR
CONVECTIVE DEVELOPMENT IN DOUBT THIS AFTERNOON...THE SEVERE
PROBABILITIES ARE RATHER LOW. BETTER CHANCES FOR SEVERE WOULD
SEEM TO BE EAST AND NORTHEAST OF OUR AREA.
IT STILL LOOKS LIKE THE CONVECTION WILL BE WELL EAST OF THE AREA
BY 00Z TUESDAY...AND THE REMAINDER OF THE SHORT TERM WILL BE
DRY WITH SURFACE HIGH PRESSURE DOMINATING THE REGION. CONSIDERED
INSERTING A SLIGHT CHANCE POP WEDNESDAY NIGHT IN THE FAR
WEST...BUT A GFS SOUNDING FROM THAT AREA WAS UNINSPIRING.
SOUTHWEST WINDS FROM MID-MORNING THROUGH MID AFTERNOON ARE
FORECAST TO BE AT OR ABOVE LAKE WIND ADVISORY CRITERIA OVER THE
EASTERN HALF OF THE AREA. HOWEVER...CONFIDENCE IN THE CONVECTIVE
EVOLUTION CASTS SOME DOUBT ON THE WIND FORECAST...SO WILL NOT
ISSUE AN ADVISORY AT THIS TIME. WILL LET THE DAY SHIFT MONITOR
TRENDS THIS MORNING AND ISSUE IF/WHEN IT BECOMES MORE OBVIOUS.
WEST NORTHWEST WINDS OVER THE NORTHERN HALF OF THE AREA WILL BE
NEAR CRITERIA ON TUESDAY AS WELL.
GENERALLY STAYED CLOSE TO THE CONSENSUS OF GUIDANCE FOR TEMPERATURES
THROUGH THE PERIOD. MAY NOT BE COLD ENOUGH TUESDAY NIGHT...WITH
DECENT RADIATIONAL COOLING REGIME AND DRY AIR IN PLACE.
.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 343 AM CDT MON MAY 11 2015
ON THE LARGER SCALE...OPERATIONAL MODELS AND THEIR ENSEMBLES ARE IN
RELATIVELY GOOD AGREEMENT THROUGH THE EXTENDED PERIOD. HOWEVER...
MUCH OF THE WEATHER DURING THIS TIME WILL BE DRIVEN BY SUBTLE
MESOSCALE FEATURES THAT RESULT IN RELATIVELY WEAK FORCING. AS A
RESULT...OUR CONFIDENCE IS ONLY AVERAGE AT BEST DURING THIS TIME.
THE UPPER LEVEL PATTERN THROUGH THE WEEKEND WILL BE DOMINATED BY A
RIDGE POSITIONED FROM THE GULF COAST NORTHWARD ACROSS THE EASTERN
HALF OF THE NATION. A LARGE UPPER LEVEL LOW OVER THE EASTERN PACIFIC
IS FORECAST TO SLOWLY MIGRATE EAST INTO THE INTERMOUNTAIN WEST LATE
IN THE WEEK...REACHING THE PLAINS LATE IN THE WEEKEND.
AS FOR THE DETAILS...HIGH PRESSURE WILL SHIFT EAST OF THE REGION BY
THURSDAY. AN UPPER LEVEL DISTURBANCE IS FORECAST TO TRACK ACROSS THE
MIDDLE AND UPPER MISSISSIPPI RIVER VALLEYS AS A WARM FRONT LIFTS
NORTH ACROSS THE REGION THURSDAY AND THURSDAY NIGHT. THE RESULTANT
INCREASE IN MOISTURE AND INSTABILITY WILL LEAD TO OUR NEXT CHANCE OF
SHOWERS AND THUNDERSTORMS DURING THIS TIME.
BY FRIDAY AND SATURDAY...THE UPPER LEVEL RIDGE BECOMES THE DOMINANT
WEATHER FEATURE. HOWEVER...RATHER WARM AND HUMID CONDITIONS WILL
PREVAIL BENEATH THIS RIDGE. EVEN THOUGH ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS CERTAINLY CANNOT BE RULED OUT...FORECAST
MODELS APPEAR TO BE OVERDONE WITH RESPECT TO PRECIPITATION CHANCES
AND COVERAGE. AS A RESULT...WE COLLABORATED WITH SURROUNDING OFFICES
TO REDUCE RAIN CHANCES TO NO HIGHER THAN 30-40 PERCENT DURING THIS
TIME. RAIN CHANCES SHOULD INCREASE LATE IN THE WEEKEND AS THE
REMNANTS OF THE UPPER LOW DRAW CLOSER.
TEMPERATURES WILL UNDERGO A SLOW WARMING TREND THROUGH THE PERIOD.
HIGHS WILL START OFF IN THE MID TO UPPER 70S ON THURSDAY...THEN
MODERATE INTO THE LOWER AND PERHAPS MID 80S BY THE WEEKEND. LOWS OF
50 TO 55 THURSDAY MORNING WILL RISE INTO THE LOWER AND MID 60S
DURING THE REMAINDER OF THE PERIOD.
&&
.AVIATION...
ISSUED AT 1148 PM CDT SUN MAY 10 2015
NEW AREA OF LIGHT SHOWERS OVER SEMO MOVING NE. WILL CARRY VCSH AND
MENTION -SHRA AT KPAH AND KCGI TO COVER THIS ACTIVITY. MAY STAY JUST
WEST OF KEVV/KOWB. LIGHT SE WINDS THE RULE. MAIN PUSH OF CONVECTIVE
ACTIVITY SHOULD BE FROM LATE MORNING THROUGH MID AFTERNOON FROM WEST
TO EAST ACROSS THE AREA MONDAY. SOUTH WINDS AHEAD OF THE ACTIVITY
SHOULD BECOME WEST/SOUTHWEST AS A FRONTAL BOUNDARY MOVES THROUGH.
MAY BE SOME MVFR CIGS AND VSBYS AT TIMES AS WELL.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
SHORT TERM...DRS
LONG TERM...RJP
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
102 PM CDT MON MAY 11 2015
.AVIATION...
LINE OF THUNDERSTORMS EXTENDS FROM HENDERSON IN SOUTH CENTRAL
LOUISIANA TO CAMERON LOUISIANA. THIS LINE IS MOVING TO THE
SOUTHEAST WHILE CELLS ARE MOVING TO THE NORTHEAST. VSBY AND
CEILINGS LWR W/ WINDS GUSTY IN AND AROUND TSTMS.
&&
.PREV DISCUSSION... /ISSUED 1108 AM CDT MON MAY 11 2015/
UPDATE...
BAND OF CONVECTION CONTINUES TO PROPAGATE SOUTHWARD ALONG THE
OUTFLOW BOUNDARY. THE LEADING EDGE OF THIS ACTIVITY WILL BE
REACHING THE I-10 CORRIDOR FROM BEAUMONT TO JENNINGS THEN BACK TO
THE NE TOWARD OPELOUSAS WITHIN THE NEXT HOUR. ADDITIONAL SCT
SHOWERS AND TSTMS ARE DEVELOPING ACRS PORTIONS OF ACADIANA AS
WELL. EXPECT THE SWD DEVELOPMENT OF THIS ACTIVITY TO SLOW OVER THE
NEXT FEW HOURS AS BOUNDARY ORIENTATION BECOMES MORE PARALLEL TO
THE MEAN FLOW ALOFT. OVERALL...EXPECT SCT TO NMRS SHOWERS AND
TSTMS TO CONTINUE THROUGH THE AFTN...MAINLY ALONG AND NORTH OF
I-10 AND ADJUSTED POP/WX GRIDS TO REFLECT THIS USING A BLEND OF
RECENT HIRES MODEL GUIDANCE. IN ADDITION...THE COMBINATION OF THE
ABV MENTIONED FACTORS AND AMPLE MOISTURE OVER THE REGION...THERE
IS THE POTENTIAL FOR SOME LOCALLY HEAVIER RAINFALL WHICH COULD
LEAD TO FLOODING OF URBAN AND LOW-LYING AREAS. THINK ANY FLOOD
RELATED PROBLEMS WILL BE LOCALIZED AND MINOR SO DO NOT THINK A
FLOOD WATCH WILL BE NECESSARY AT THIS TIME.
WITH WIDESPREAD CLOUDS AND SHOWERS CROSSING THE
AREA...TEMPERATURES ARE IN THE 60S ACRS THE NRN CWA WITH LOCATIONS
ALONG I-10 HAVING REACHED THE LOWER 80S JUST AHEAD OF THE LINE OF
CONVECTION. EXPECT TEMPS TO FALL BACK INTO THE 70S AS THE SHOWERS
REACH I-10. RECOVERY WILL DEPEND ON WHETHER ANY SUN CAN BREAK
THROUGH DURING THE AFTN...BUT HAVE ADJUSTED HOURLY TEMPS AND
DEWPOINTS BASED ON RECENT OBS AND TRENDED A LITTLE COOLER ON
HOURLY TEMPS THROUGH THE AFTN. ALSO ADJUSTED MAX TEMPS DOWNWARD
A BIT AS WELL...ESPECIALLY ACRS THE NRN ZONES. 24
PREV DISCUSSION... /ISSUED 644 AM CDT MON MAY 11 2015/
AVIATION...THE HIGH RESOLUTION SHORT RANGE MODEL TAKES THE BAND
OF SHOWERS AND THUNDERSTORMS APROACHING FROM THE NORTHWEST INTO
THE TERMINALS LATER THIS MORNING. POSSIBLE CONDITIONS AS LOW AS
LIFR CIGS WITH RAIN ASSUMING THE CURRENT ACTIVITY WEAKENS AS SOME
SIGNS HAVE INDICATED. SINCE ATMOSPHERE WOULD BE WORKED OVER BY THIS
AFTERNOON WILL GO WITH VFR CIGS WITH VCTS. LATE TNITE AS THE WEAK
FRONT APPROACHES, MVFR WITH LIGHT RAIN.
SWEENEY
PREV DISCUSSION... /ISSUED 343 AM CDT MON MAY 11 2015/
DISCUSSION...MAIN FORECAST ISSUE WILL BE POPS THROUGHOUT THE
WEEK.
LINE OF THUNDERSTORMS OVER NE TEXAS HAS SLOWLY SHIFTED SE DURING THE
NIGHT. LATEST HRRR MAY BE A LITTLE QUICK IN PUSHING THE LINE INTO
NW PART OF THE FORECAST AREA BY 12Z...BUT THERE IS CERTAINLY
POTENTIAL FOR CONVECTION DEVELOPING AHEAD OF THE LINE BY THAT
TIME. EVEN IF LINE WEAKENS...REMNANT BOUNDARIES COMBINED WITH
RICH THTE AIR WILL LIKELY KEEP GOOD COVERAGE OF SHOWERS AND
THUNDERSTORMS FOR TODAY ESPECIALLY ACROSS EAST TEXAS AND CENTRAL
LOUISIANA. WILL TWEAK CURRENT POPS FORECAST FOR TODAY BUT OVERALL
NOT MUCH CHANGE FROM PREVIOUS FORECASTS.
FOR TUESDAY...MODELS SHOW VIGOROUS SHORTWAVE IN UPPER SW FLOW AND
THIS SHOULD FURTHER ENHANCE SHOWER AND THUNDERSTORM CHANCES.
A SERIES OF UPPER SHORT WAVE TROUGHS WILL MOVE THROUGH THE
WESTERN U.S. THROUGH THE WEEK. ALSO...MODELS ARE SHOWING A BROAD
NEGATIVELY TILTED TROUGH BECOMING ESTABLISHED OVER THE WEST COAST
BY LATE IN THE WEEK. AT THE SURFACE...FRONTAL BOUNDARY IS
FORECASTED TO MOVE INTO THE AREA AND STALL THROUGH AT LEAST
WEDNESDAY. A VERY MOIST AIRMASS WILL REMAIN IN PLACE THROUGH THE
WEEK. WILL THEREFORE MAINTAIN MAINLY DIURNAL SCATTERED SHOWERS AND
THUNDERSTORMS THROUGH THE REMAINDER OF THE WEEK. WILL LOWER POPS
SLIGHTLY OVER THE WEEKEND AS SURFACE BOUNDARY SHOULD BE LESS
DEFINED OR DIFFUSE.
MARINE....WILL ALLOW SCEC TO EXPIRE AT 5 AM FOR INNER AND OUTER
WATERS. WITH BOUNDARY APPROACHING THE AREA ON TUESDAY...GRADIENT
SHOULD WEAKEN AND LOW LEVEL FLOW SHOULD BECOME MORE EASTERLY.
PROGRESSION OF HIGH PRESSURE TOWARD THE EAST COAST WILL ALLOW FOR
A WEAK SOUTHERLY FLOW FOR THE REMAINDER OF THE WEEK.
04
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 68 79 65 83 / 80 70 30 50
LCH 71 83 70 83 / 50 70 30 40
LFT 72 84 70 85 / 40 60 30 40
BPT 72 82 71 83 / 60 70 30 40
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
$$
AVIATION...19
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1108 AM CDT MON MAY 11 2015
.UPDATE...
BAND OF CONVECTION CONTINUES TO PROPAGATE SOUTHWARD ALONG THE
OUTFLOW BOUNDARY. THE LEADING EDGE OF THIS ACTIVITY WILL BE
REACHING THE I-10 CORRIDOR FROM BEAUMONT TO JENNINGS THEN BACK TO
THE NE TOWARD OPELOUSAS WITHIN THE NEXT HOUR. ADDITIONAL SCT
SHOWERS AND TSTMS ARE DEVELOPING ACRS PORTIONS OF ACADIANA AS
WELL. EXPECT THE SWD DEVELOPMENT OF THIS ACTIVITY TO SLOW OVER THE
NEXT FEW HOURS AS BOUNDARY ORIENTATION BECOMES MORE PARALLEL TO
THE MEAN FLOW ALOFT. OVERALL...EXPECT SCT TO NMRS SHOWERS AND
TSTMS TO CONTINUE THROUGH THE AFTN...MAINLY ALONG AND NORTH OF
I-10 AND ADJUSTED POP/WX GRIDS TO REFLECT THIS USING A BLEND OF
RECENT HIRES MODEL GUIDANCE. IN ADDITION...THE COMBINATION OF THE
ABV MENTIONED FACTORS AND AMPLE MOISTURE OVER THE REGION...THERE
IS THE POTENTIAL FOR SOME LOCALLY HEAVIER RAINFALL WHICH COULD
LEAD TO FLOODING OF URBAN AND LOW-LYING AREAS. THINK ANY FLOOD
RELATED PROBLEMS WILL BE LOCALIZED AND MINOR SO DO NOT THINK A
FLOOD WATCH WILL BE NECESSARY AT THIS TIME.
WITH WIDESPREAD CLOUDS AND SHOWERS CROSSING THE
AREA...TEMPERATURES ARE IN THE 60S ACRS THE NRN CWA WITH LOCATIONS
ALONG I-10 HAVING REACHED THE LOWER 80S JUST AHEAD OF THE LINE OF
CONVECTION. EXPECT TEMPS TO FALL BACK INTO THE 70S AS THE SHOWERS
REACH I-10. RECOVERY WILL DEPEND ON WHETHER ANY SUN CAN BREAK
THROUGH DURING THE AFTN...BUT HAVE ADJUSTED HOURLY TEMPS AND
DEWPOINTS BASED ON RECENT OBS AND TRENDED A LITTLE COOLER ON
HOURLY TEMPS THROUGH THE AFTN. ALSO ADJUSTED MAX TEMPS DOWNWARD
A BIT AS WELL...ESPECIALLY ACRS THE NRN ZONES. 24
&&
.PREV DISCUSSION... /ISSUED 644 AM CDT MON MAY 11 2015/
AVIATION...THE HIGH RESOLUTION SHORT RANGE MODEL TAKES THE BAND
OF SHOWERS AND THUNDERSTORMS APROACHING FROM THE NORTHWEST INTO
THE TERMINALS LATER THIS MORNING. POSSIBLE CONDITIONS AS LOW AS
LIFR CIGS WITH RAIN ASSUMING THE CURRENT ACTIVITY WEAKENS AS SOME
SIGNS HAVE INDICATED. SINCE ATMOSPHERE WOULD BE WORKED OVER BY THIS
AFTERNOON WILL GO WITH VFR CIGS WITH VCTS. LATE TNITE AS THE WEAK
FRONT APPROACHES, MVFR WITH LIGHT RAIN.
SWEENEY
PREV DISCUSSION... /ISSUED 343 AM CDT MON MAY 11 2015/
DISCUSSION...MAIN FORECAST ISSUE WILL BE POPS THROUGHOUT THE
WEEK.
LINE OF THUNDERSTORMS OVER NE TEXAS HAS SLOWLY SHIFTED SE DURING THE
NIGHT. LATEST HRRR MAY BE A LITTLE QUICK IN PUSHING THE LINE INTO
NW PART OF THE FORECAST AREA BY 12Z...BUT THERE IS CERTAINLY
POTENTIAL FOR CONVECTION DEVELOPING AHEAD OF THE LINE BY THAT
TIME. EVEN IF LINE WEAKENS...REMNANT BOUNDARIES COMBINED WITH
RICH THTE AIR WILL LIKELY KEEP GOOD COVERAGE OF SHOWERS AND
THUNDERSTORMS FOR TODAY ESPECIALLY ACROSS EAST TEXAS AND CENTRAL
LOUISIANA. WILL TWEAK CURRENT POPS FORECAST FOR TODAY BUT OVERALL
NOT MUCH CHANGE FROM PREVIOUS FORECASTS.
FOR TUESDAY...MODELS SHOW VIGOROUS SHORTWAVE IN UPPER SW FLOW AND
THIS SHOULD FURTHER ENHANCE SHOWER AND THUNDERSTORM CHANCES.
A SERIES OF UPPER SHORT WAVE TROUGHS WILL MOVE THROUGH THE
WESTERN U.S. THROUGH THE WEEK. ALSO...MODELS ARE SHOWING A BROAD
NEGATIVELY TILTED TROUGH BECOMING ESTABLISHED OVER THE WEST COAST
BY LATE IN THE WEEK. AT THE SURFACE...FRONTAL BOUNDARY IS
FORECASTED TO MOVE INTO THE AREA AND STALL THROUGH AT LEAST
WEDNESDAY. A VERY MOIST AIRMASS WILL REMAIN IN PLACE THROUGH THE
WEEK. WILL THEREFORE MAINTAIN MAINLY DIURNAL SCATTERED SHOWERS AND
THUNDERSTORMS THROUGH THE REMAINDER OF THE WEEK. WILL LOWER POPS
SLIGHTLY OVER THE WEEKEND AS SURFACE BOUNDARY SHOULD BE LESS
DEFINED OR DIFFUSE.
MARINE....WILL ALLOW SCEC TO EXPIRE AT 5 AM FOR INNER AND OUTER
WATERS. WITH BOUNDARY APPROACHING THE AREA ON TUESDAY...GRADIENT
SHOULD WEAKEN AND LOW LEVEL FLOW SHOULD BECOME MORE EASTERLY.
PROGRESSION OF HIGH PRESSURE TOWARD THE EAST COAST WILL ALLOW FOR
A WEAK SOUTHERLY FLOW FOR THE REMAINDER OF THE WEEK.
04
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 83 68 79 65 / 80 80 70 30
LCH 83 71 83 70 / 70 50 70 30
LFT 84 72 84 70 / 50 40 60 30
BPT 84 72 82 71 / 80 60 70 30
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
644 AM CDT MON MAY 11 2015
.AVIATION...THE HIGH RESOLUTION SHORT RANGE MODEL TAKES THE BAND
OF SHOWERS AND THUNDERSTORMS APROACHING FROM THE NORTHWEST INTO
THE TERMINALS LATER THIS MORNING. POSSIBLE CONDITIONS AS LOW AS
LIFR CIGS WITH RAIN ASSUMING THE CURRENT ACTIVITY WEAKENS AS SOME
SIGNS HAVE INDICATED. SINCE ATMOSPHERE WOULD BE WORKED OVER BY THIS
AFTERNOON WILL GO WITH VFR CIGS WITH VCTS. LATE TNITE AS THE WEAK
FRONT APPROACHES, MVFR WITH LIGHT RAIN.
SWEENEY
&&
.PREV DISCUSSION... /ISSUED 343 AM CDT MON MAY 11 2015/
DISCUSSION...MAIN FORECAST ISSUE WILL BE POPS THROUGHOUT THE
WEEK.
LINE OF THUNDERSTORMS OVER NE TEXAS HAS SLOWLY SHIFTED SE DURING THE
NIGHT. LATEST HRRR MAY BE A LITTLE QUICK IN PUSHING THE LINE INTO
NW PART OF THE FORECAST AREA BY 12Z...BUT THERE IS CERTAINLY
POTENTIAL FOR CONVECTION DEVELOPING AHEAD OF THE LINE BY THAT
TIME. EVEN IF LINE WEAKENS...REMNANT BOUNDARIES COMBINED WITH
RICH THTE AIR WILL LIKELY KEEP GOOD COVERAGE OF SHOWERS AND
THUNDERSTORMS FOR TODAY ESPECIALLY ACROSS EAST TEXAS AND CENTRAL
LOUISIANA. WILL TWEAK CURRENT POPS FORECAST FOR TODAY BUT OVERALL
NOT MUCH CHANGE FROM PREVIOUS FORECASTS.
FOR TUESDAY...MODELS SHOW VIGOROUS SHORTWAVE IN UPPER SW FLOW AND
THIS SHOULD FURTHER ENHANCE SHOWER AND THUNDERSTORM CHANCES.
A SERIES OF UPPER SHORT WAVE TROUGHS WILL MOVE THROUGH THE
WESTERN U.S. THROUGH THE WEEK. ALSO...MODELS ARE SHOWING A BROAD
NEGATIVELY TILTED TROUGH BECOMING ESTABLISHED OVER THE WEST COAST
BY LATE IN THE WEEK. AT THE SURFACE...FRONTAL BOUNDARY IS
FORECASTED TO MOVE INTO THE AREA AND STALL THROUGH AT LEAST
WEDNESDAY. A VERY MOIST AIRMASS WILL REMAIN IN PLACE THROUGH THE
WEEK. WILL THEREFORE MAINTAIN MAINLY DIURNAL SCATTERED SHOWERS AND
THUNDERSTORMS THROUGH THE REMAINDER OF THE WEEK. WILL LOWER POPS
SLIGHTLY OVER THE WEEKEND AS SURFACE BOUNDARY SHOULD BE LESS
DEFINED OR DIFFUSE.
MARINE....WILL ALLOW SCEC TO EXPIRE AT 5 AM FOR INNER AND OUTER
WATERS. WITH BOUNDARY APPROACHING THE AREA ON TUESDAY...GRADIENT
SHOULD WEAKEN AND LOW LEVEL FLOW SHOULD BECOME MORE EASTERLY.
PROGRESSION OF HIGH PRESSURE TOWARD THE EAST COAST WILL ALLOW FOR
A WEAK SOUTHERLY FLOW FOR THE REMAINDER OF THE WEEK.
04
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 84 68 79 65 / 60 70 70 30
LCH 83 71 83 70 / 50 50 70 30
LFT 86 72 84 70 / 40 40 60 30
BPT 83 72 82 71 / 50 60 70 30
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
$$
AVIATION...11
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
405 AM CDT MON MAY 11 2015
.SHORT TERM...
A MUCH MORE UNSETTLED WEATHER REGIME WILL TAKE HOLD OF THE AREA
TODAY...AND REMAIN IN PLACE THROUGH THE MIDDLE OF THE WEEK AS A
SERIES OF WEAK UPPER LEVEL SHORTWAVE TROUGHS RIDE ALONG THE
PERIPHERY OF A BROAD UPPER LEVEL RIDGE CENTERED OVER THE GULF OF
MEXICO. ADDITIONALLY...A WEAK SURFACE FRONT WILL STALL ALONG THE
INTERSTATE 10 CORRIDOR MONDAY NIGHT INTO TUESDAY AND SLOWLY
DISSIPATE THROUGH WEDNESDAY. THIS BOUNDARY WILL SERVE AS A FOCUS
FOR CONVECTIVE ACTIVITY BEGINNING THIS AFTERNOON AND PERSISTING
INTO WEDNESDAY.
THERE WILL BE SEVERAL ROUNDS OF HIGHER POPS ASSOCIATED WITH EACH
PASSING UPPER LEVEL VORT LOBE. THE INITIAL SURGE OF HIGHER POPS
WILL DEVELOP LATE THIS MORNING AND PERSIST INTO TOMORROW...AS A
VIGOROUS UPPER LEVEL FEATURE EJECTS OUT OF TEXAS AND SLIDES
THROUGH THE LOWER MISSISSIPPI. CONVECTION SHOULD DEVELOP OVER
CENTRAL LOUISIANA THIS MORNING AS A COLD FRONT APPROACHES FROM THE
WEST...AND ACCORDING THE LATEST HRRR MODEL RUNS...DRIVE A LINE OF
CONVECTION THROUGH THE NORTHWEST PORTION OF THE CWA DURING THE
AFTERNOON HOURS. ALTHOUGH MODEL SOUNDING PROFILES ARE NOT SHOWING
A VERY HIGH SEVERE POTENTIAL...THERE COULD BE SOME LOCALLY GUSTY
WINDS AND POSSIBLY SOME HAIL WITH THESE THUNDERSTORMS AS THEY MOVE
THROUGH THIS AFTERNOON. ANY STRONGER CONVECTION SHOULD BE FAIRLY
ISOLATED. THIS CONVECTION WILL SLOWLY DISSIPATE DURING THE
EVENING HOURS...BUT THE MESOHIGH AND COOLER AIRMASS LEFT IN THE
WAKE OF THE SYSTEM SHOULD ALLOW THE WEAK FRONTAL BOUNDARY TO
CONTINUE TO SLIDE INTO THE AREA DURING THE OVERNIGHT HOURS.
THE FRONT WILL STALL ALONG THE I-10 CORRIDOR TOMORROW AS THE
PARENT UPPER LEVEL TROUGH MOVES WELL TO THE NORTH AND EAST AND THE
DENSITY DIFFERENTIAL IN THE VICINITY OF THE FRONT WANES. AS THIS
OCCURS...THE HEART OF THE STRONG UPPER LEVEL VORT KICKING OUT OF
TEXAS WILL PASS DIRECTLY OVER THE FORECAST AREA. THERE WILL BE A
GRADIENT TO THE RAIN CHANCES WITH HIGHER CHANCES EXPECTED ALONG
AND NORTH OF THE FRONTAL BOUNDARY. FURTHER TO THE SOUTH...ONLY
ISOLATED COVERAGE IS EXPECTED THROUGH WEDNESDAY. THE REASON FOR
THIS GRADIENT IS THAT DECENT ISENTROPIC FORCING IS EXPECTED IN
THE VICINITY OF THE FRONT DURING THE DAY TOMORROW. THIS STRONGER
LOW LEVEL FORCING...COMBINED WITH THE VERY STRONG OMEGA ALOFT WILL
BRING MORE NUMEROUS SHOWERS AND THUNDERSTORMS TO AREAS NORTH OF
THE I-10 CORRIDOR.
RAIN CHANCES WILL BEGIN TO DECREASE RATHER QUICKLY TUESDAY NIGHT
AND SHOULD BE MUCH LOWER FOR WEDNESDAY AND THURSDAY AS THE INITIAL
VORT LOBE PUSHES TO THE EAST AND WEAKENS DRAMATICALLY. AT THE SAME
TIME...THE UPPER LEVEL RIDGE AXIS OVER THE GULF WILL ONCE AGAIN
BEGIN TO BUILD NORTHWARD AND SHOULD BE STRETCHED ACROSS THE
SOUTHEASTERN CONUS BOTH WEDNESDAY AND THURSDAY. THE FORECAST AREA
WILL TEND TO BE ON THE WESTERN PERIPHERY OF THIS RIDGE...AND HAVE
A NORTHWEST TO SOUTHEAST GRADIENT IN THE POPS FOR BOTH DAYS.
WEDNESDAY WILL BE THE DRIER OF THE TWO DAYS...DUE TO A LACK OF
FORCING ALOFT...AND ACTUALLY SOME WEAK SUBSIDENCE TAKING HOLD
ALOFT. THIS SUBSIDENCE MAY BE ENOUGH TO EFFECTIVELY CAP OFF MOST
OF THE CONVECTION. HOWEVER...WITH THE WEAK FRONTAL BOUNDARY STILL
LINGERING OVER THE AREA...THERE COULD BE JUST ENOUGH LOW LEVEL
CONVERGENCE TO OVERCOME THE CAP DURING PEAK HEATING HOURS AND FIRE
OFF A FEW SHOWERS AND THUNDERSTORMS. THUS...KEEP LOW END CHANCE
POPS IN PLACE FOR THE NORTHERN PARTS OF THE FORECAST AREA. ANOTHER
SHORTWAVE TROUGH WILL SLIDE INTO THE LOWER MISSISSIPPI VALLEY ON
THURSDAY...AND THIS STRONGER FORCING ALOFT WILL ALLOW FOR HIGHER
CONVECTIVE COVERAGE THROUGH THE DAY. HAVE WENT WITH CHANCE POPS
FOR MOST OF THE FORECAST AREA.
.LONG TERM...
A VERY SUMMER LIKE PATTERN WILL DEVELOP OVER THE AREA FOR THE
UPCOMING WEEKEND. THE ENTIRE REGION WILL BE BENEATH DEEP LAYER
ONSHORE FLOW ON THE WESTERN PERIPHERY OF DEEP LAYER RIDGING...WHICH
WILL KEEP A WARM AND HUMID AIRMASS OVER THE AREA. A WEAK VORT MAX
WILL SLIP THROUGH THE AREA ON FRIDAY...AND THIS DAY WILL SEE THE
HIGHEST OVERALL POPS AT 40 TO 50 PERCENT. OTHERWISE...POPS WILL
GENERALLY RANGE IN THE 30 TO 40 PERCENT RANGE FOR SATURDAY AND
SUNDAY SIMPLY DUE TO A LACK OF CAPPING ALOFT AND DAYTIME HEATING
INDUCING ENOUGH INSTABILITY TO SPARK CONVECTION. THE SHOWERS AND
THUNDERSTORMS WILL BE MOST LIKELY TO DEVELOP ALONG ANY MESOSCALE
BOUNDARIES LIKE SEABREEZES AND LINGERING OUTFLOW BOUNDARIES. THE
CONVECTION WILL TEND TO DEVELOP AS TEMPERATURES WARM IN THE LATE
MORNING AND PERSIST INTO THE EARLY EVENING HOURS. AS TEMPERATURES
COOL...THE CONVECTION WILL DISSIPATE DURING THE OVERNIGHT HOURS
WITH MAINLY DRY CONDITIONS EXPECTED OVER LAND AREAS BY MIDNIGHT.
TEMPERATURES WILL REMAIN QUITE WARM...WITH HIGHS IN THE UPPER 80S
AND LOWS IN THE UPPER 60S AND LOWER 70S EACH DAY.
&&
.AVIATION...
SOME MVFR CEILINGS IN PLACE AROUND THE AREA WITH MARINE LAYER THAT SHOULD
LIFT TO VFR LEVELS AFTER 15Z. QUASI-LINEAR CONVECTIVE SYSTEM
MOVING OUT OF ARKLATEX REGION IS PROGGED TO MOVE INTO KBTR AROUND
18Z...KMCB 19Z...KHDC 20Z...KASD 22Z...THEN WEAKENING UPON ARRIVAL
AT KMSY/KNEW/KGPT GENERALLY BETWEEN 23Z-02Z. WILL HANDLE WITH 2-3
HOUR WINDOW OF EITHER PREVAILING TSRA OR TEMPO TSRA FOR THE 4
TERMINALS PRIOR TO 22Z...THEN PROB30 FOR SOUTHEASTERNMOST
TERMINALS AFTER 23Z. A RATHER LAZY FRONTAL PASSAGE WITH CONVECTIVE
PASSAGE PRIMARILY THE FRONT BUT WITH LITTLE HIGH PRESSURE SUPPORT
UNTIL AFTER TUE 12Z. THERE MAY BE A BRIEF WINDOW OF RADIATIONAL
FOG DEVELOPMENT WITH RESIDUAL MOISTURE IN PLACE BUT APPROACH OF
UPPER DISTURBANCE AND RENEWED CONVECTIVE DEVELOPMENT MAY DISRUPT
ANY LINGERING FOG PRIOR TO 12Z. 24/RR
&&
.MARINE...
A PERSISTENT ONSHORE FLOW OF 10 TO 15 KNOTS WILL DOMINATE THE
MARINE ZONES THROUGH TUESDAY. SEAS OF 2 TO 4 FEET AND A PERIOD OF
4 TO 6 SECONDS CAN BE EXPECTED IN THE OPEN GULF WATERS DURING THIS
PERIOD. WAVES OF 1 TO 2 FEET AND A PERIOD OF AROUND 2 SECONDS IS
EXPECTED IN THE SOUNDS AND LAKES. A WEAK FRONTAL BOUNDARY WILL
BRING A WIND SHIFT TO THE NORTHEAST TUESDAY NIGHT INTO WEDNESDAY
MORNING...BUT WINDS WILL QUICKLY SHIFT BACK TO THE SOUTHEAST BY
WEDNESDAY AFTERNOON AS THIS FRONT WASHES OUT. THIS SOUTHEAST FLOW
OF AROUND 10 KNOTS WILL PERSIST INTO THE UPCOMING WEEKEND.
OVERALL...NO SIGNIFICANT WEATHER IMPACTS ARE EXPECTED IN THE
MARINE ZONES THROUGH THE ENTIRE FORECAST PERIOD.
&&
.DECISION SUPPORT...
DSS CODE...GREEN.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...ASSESSING SEVERE TSTM POTENTIAL FOR NEXT FEW DAYS.
DECISION SUPPORT SERVICES (DSS) CODE LEGEND
GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION
BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH
VISIBILITY EVENT
YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED
WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT
ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY
TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES
RED = FULL ENGAGEMENT FOR MODERATE RISK SVR AND/OR DIRECT
TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 87 69 83 65 / 40 60 60 60
BTR 88 70 85 67 / 40 60 60 60
ASD 87 69 85 66 / 20 40 50 50
MSY 87 71 85 70 / 20 40 40 40
GPT 85 72 85 69 / 10 40 40 40
PQL 86 69 85 66 / 10 30 40 40
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...NONE.
MS...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1129 PM EDT TUE MAY 12 2015
.SYNOPSIS...
LOW PRESSURE WILL CONTINUE ACROSS QUEBEC TONIGHT BRINGING A COLD
FRONT INTO THE AREA. THE COLD FRONT WILL PUSH OFF THE COAST WEDNESDAY
MORNING. HIGH PRESSURE WILL BUILD TOWARD THE REGION LATER
WEDNESDAY NIGHT INTO THURSDAY.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
11:30 PM UPDATE...INCREASED PRECIPITATION COVERAGE OVER THE NORTH
WHERE WIDESPREAD SHOWERS, SOME BRIEFLY HEAVY, ARE ACCOMPANYING THE
COLD FRONT. SHOWERS ARE EXPECTED TO THIN OUT A BIT AS THE FRONT
PUSHES SOUTH. ALSO RAISED TEMPS MAINLY DOWNEAST EARLY TONIGHT IN
WARM AIR AHEAD OF THE FRONT.
PREVIOUS DISCUSSION...
ISOLATED THUNDERSTORMS POSSIBLE W/SOME DECENT WIND GUSTS.
LOW CLOUDS SLOWLY ERODING ACROSS THE EASTERN AREAS THIS AFTERNOON
KEEPING THE LLVLS STABLE WHILE WESTERN AND SW AREAS HAVE BROKEN
OUT W/SUNSHINE AND HENCE TEMPS WARMING. THIS HAS ALLOWED FOR
THINGS TO DESTABILIZE MORE. 18Z SURFACE ANALYSIS HAD THE WARM
FRONT/PRE-FRONTAL BOUNDARY SLOWLY LIFT INTO WESTERN MAINE W/THE
COLD FRONT STILL BACK WESTERN QUEBEC. STEADY RAIN HAS ENDED OR
MOVED E W/A MORE SHOWERY NATURE OF THE PRECIP SETTING UP. LATEST
NAM AND RAP SOUNDINGS SUPPORT DECENT SB/MU CAPE OF 700+ JOULES
W/LIS DOWN TO -2 IN THESE AREAS. GOOD SHEAR IN THE 0-6KM LAYER
AROUND 35 KTS. SPC MESO ANALYSIS SHOWED DECENT MID LEVEL LAPSE
RATES OF 6.5 C/KM HELPING W/INSTABILITY. KEPT ENHANCED WORDING FOR
FOR NOW FOR GUSTY WINDS AND HEAVY RAINFALL POTENTIAL. THINGS WILL
WIND DOWN ACROSS THE W AND SW THIS EVENING AND THEN SHIFT ACROSS
THE NORTHERN AREAS AS THE COLD FRONT APCHS W/LOW PRES PASSING
ACROSS SOUTHERN QUEBEC. 12Z UA SHOWED DECENT MID LEVEL COOLING AND
STRONG JET FROM 700-500MBS OF AROUND 65 KTS. THOSE STRONGER WINDS
COULD GET MIXED DOWN SOME TO THE SFC W/ANY ELEVATED CONVECTION.
LEANED W/ENHANCED WORDING FOR THE GUSTY WINDS IN ANY STORMS
THROUGH MIDNIGHT. HEAVY RAINFALL POTENTIAL IS POSSIBLE AS WELL
W/THE STORMS MOVING PARALLEL TO THE UPPER FLOW.
CONVECTIVE POTENTIAL WINDS DOWN AFTER MIDNIGHT W/JUST SHOWERS AND
THE BULK OF THE ACTION ACROSS THE NORTHERN TIER. COOLING TO TAKE
AFFECT AS NW WIND TAKE OVER THROUGH THE COLUMN. WE ARE TALKING
UPPER 30S BACK ACROSS THE WNW BY EARLY WEDNESDAY MORNING W/40S
ELSEWHERE. THIS COLD AIR CAN BE SEEN ALREADY SHOWING UP IN NW
QUEBEC. WEDNESDAY WILL BE MUCH COOLER W/THE UPPER TROF ACROSS THE
REGION W/UPPER 50S NORTH AND WEST WHILE CENTRAL AND DOWNEAST WILL
SEE AROUND 60F OR SO DUE TO SOME DOWNSLOPING. IT WILL BE BREEZY
W/NW WINDS.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
STRONG HIGH PRESSURE WILL BUILD IN FROM THE WEST AND WEDNESDAY
NIGHT AND CREST OVER THE REGION EARLY FRIDAY KEEPING THE STATE
RELATIVELY DRY. WILL BLEND THE GFS AND ECMWF FOR POPS... QPF AND
SKY CONDITIONS. FOR WINDS HAVE USED THE MOSG25. THE SUPER BLEND
WAS USED TO POPULATE THE TEMPERATURE AND DEW POINT GRIDS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
STRONG HIGH PRESSURE WILL MOVE OFF THE EAST COAST LATE FRIDAY.
WEAK LOW PRESSURE WILL PASS TO THE SOUTH OF THE REGION SATURDAY.
HIGH PRESSURE WILL THEN BUILD IN FROM THE NORTH MONDAY. A COLD
FRONT WILL APPROACH FROM THE WEST MONDAY NIGHT AND CROSS THE
REGION TUESDAY. WILL USE THE SUPER BLEND TO POPULATE ALL GRIDS.
&&
.AVIATION /04Z WEDNESDAY THROUGH SUNDAY/...
NEAR TERM: MOSTLY VFR EARLY THIS EVENING AT THE NORTHERN
TERMINALS WITH CONDITIONS TO DROP BACK TO MVFR AND LOCAL IFR
W/THE APCHG COLD FRONT. IMPROVEMENT TO MVFR BY MID MORNING AND
VFR BY LATE IN THE DAY. KBGR AND KBHB WILL SEE VFR THROUGH
TUESDAY.
SHORT TERM: EXPECT VFR CONDITIONS WEDNESDAY NIGHT THROUGH SUNDAY.
&&
.MARINE...
NEAR TERM: SCA FOR HAZARDOUS SEAS IS IN EFFECT INCLUDING THE
INTRA-COASTAL ZONE. A SWELL BEING GENERATED FROM LEFTOVER TD ANA
IS FORECAST LIFT ACROSS THE WATERS LATER THIS EVENING INTO
WEDNESDAY. DECIDED ON HEIGHTS UP TO A RANGE OF 6-7 FT W/THE
HIGHEST WAVES OVER THE OUTER WATERS. THE INTRA-COASTAL ZONE WILL
MOST LIKELY SEE WAVES OF AROUND 5FT W/A 8-9 SECOND PERIOD. FOG
WILL BE A NUISANCE FOR NAVIGATION THROUGH TONIGHT.
FOR THE WINDS, DECIDED ATTM TO KEEP WIND GUSTS IN THE LOWER 2OS
ON WEDNESDAY W/THE NW FLOW. THE OUTER WATERS COULD SEE GUSTS HIT
25 KT FOR A BRIEF PERIOD.
SHORT TERM: HAVE BLENDED THE NAM12 AND GFS40 FOR SUSTAINED WINDS
WEDNESDAY NIGHT THROUGH FRIDAY THEN TRANSITION TO THE SUPER BLEND
WINDS. FOR WAVES: PRIMARY WAVE SYSTEM WILL BE LONG PERIOD SWELL
FROM REMNANTS OF TROPICAL DEPRESSION ANA. EXPECT 5 FEET/9-10
SECONDS WAVE HEIGHTS WEDNESDAY NIGHT SUBSIDING DURING THE DAY
THURSDAY. WILL CARRY AN SCA EARLY WEDNESDAY EVENING BUT EXPECT
SEAS TO SUBSIDE BELOW SCA LATER AT NIGHT AS THE LONG PERIOD WAVE
SYSTEM SUBSIDES. WILL USE THE NEAR SHORE WAVE MODEL THROUGH FRIDAY
THEN TRANSITION TO THE WAVE WATCH III.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL MIDNIGHT EDT
WEDNESDAY NIGHT FOR ANZ050>052.
&&
$$
NEAR TERM...CB/HEWITT/MCB
SHORT TERM...MIGNONE
LONG TERM...MIGNONE
AVIATION...CB/HEWITT/MIGNONE
MARINE...CB/HEWITT/MIGNONE
AREA FORECAST DISCUSSION
NWS CARIBOU ME
922 PM EDT TUE MAY 12 2015
.SYNOPSIS...
LOW PRESSURE WILL CONTINUE ACROSS QUEBEC TONIGHT BRINGING A COLD
FRONT INTO THE AREA. THE COLD FRONT WILL PUSH OFF THE COAST WEDNESDAY
MORNING. HIGH PRESSURE WILL BUILD TOWARD THE REGION LATER
WEDNESDAY NIGHT INTO THURSDAY.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
922 PM UPDATE...A STRONG COLD FRONT IS ENTERING FAR NORTHERN
MAINE AND IS CURRENTLY IN THE ST JOHN VALLEY. THE FRONT WILL SWEEP
ACROSS THE CWA TON REACHING THE DOWNEAST REGION EARLY WED
MORNING...AND WILL MOVE OFFSHORE BY MID-MORNING. A LINE OF
SHOWERS CURRENTLY ACCOMPANIES THE FRONT. THERE HAVE NOT BEEN ANY
CLOUD TO GROUND OR EVEN IN CLOUD LIGHTNING STRIKES DETECTED WITHIN
THE PAST HOUR. WILL UPDATE THE POP GRIDS BASED ON THE LATEST RADAR
AND NEAR TERM MODEL TRENDS. WILL ALSO REMOVE THE MENTION OF
THUNDER FOR THE MAJORITY OF THE CWA WITH THE EXCEPTION OF THE FAR
NORTH DURING THE NEXT 1-2 HOURS. OTHERWISE...ONLY MINOR
ADJUSTMENTS TO THE OTHER FORECAST ELEMENTS BASED ON THE 9 PM
OBSERVATIONS AND EXPECTED CONDITIONS FOR THE REMAINDER OF THE
NIGHT.
PREVIOUS DISCUSSION...
ISOLATED THUNDERSTORMS POSSIBLE W/SOME DECENT WIND GUSTS.
LOW CLOUDS SLOWLY ERODING ACROSS THE EASTERN AREAS THIS AFTERNOON
KEEPING THE LLVLS STABLE WHILE WESTERN AND SW AREAS HAVE BROKEN
OUT W/SUNSHINE AND HENCE TEMPS WARMING. THIS HAS ALLOWED FOR
THINGS TO DESTABILIZE MORE. 18Z SURFACE ANALYSIS HAD THE WARM
FRONT/PRE-FRONTAL BOUNDARY SLOWLY LIFT INTO WESTERN MAINE W/THE
COLD FRONT STILL BACK WESTERN QUEBEC. STEADY RAIN HAS ENDED OR
MOVED E W/A MORE SHOWERY NATURE OF THE PRECIP SETTING UP. LATEST
NAM AND RAP SOUNDINGS SUPPORT DECENT SB/MU CAPE OF 700+ JOULES
W/LIS DOWN TO -2 IN THESE AREAS. GOOD SHEAR IN THE 0-6KM LAYER
AROUND 35 KTS. SPC MESO ANALYSIS SHOWED DECENT MID LEVEL LAPSE
RATES OF 6.5 C/KM HELPING W/INSTABILITY. KEPT ENHANCED WORDING FOR
FOR NOW FOR GUSTY WINDS AND HEAVY RAINFALL POTENTIAL. THINGS WILL
WIND DOWN ACROSS THE W AND SW THIS EVENING AND THEN SHIFT ACROSS
THE NORTHERN AREAS AS THE COLD FRONT APCHS W/LOW PRES PASSING
ACROSS SOUTHERN QUEBEC. 12Z UA SHOWED DECENT MID LEVEL COOLING AND
STRONG JET FROM 700-500MBS OF AROUND 65 KTS. THOSE STRONGER WINDS
COULD GET MIXED DOWN SOME TO THE SFC W/ANY ELEVATED CONVECTION.
LEANED W/ENHANCED WORDING FOR THE GUSTY WINDS IN ANY STORMS
THROUGH MIDNIGHT. HEAVY RAINFALL POTENTIAL IS POSSIBLE AS WELL
W/THE STORMS MOVING PARALLEL TO THE UPPER FLOW.
CONVECTIVE POTENTIAL WINDS DOWN AFTER MIDNIGHT W/JUST SHOWERS AND
THE BULK OF THE ACTION ACROSS THE NORTHERN TIER. COOLING TO TAKE
AFFECT AS NW WIND TAKE OVER THROUGH THE COLUMN. WE ARE TALKING
UPPER 30S BACK ACROSS THE WNW BY EARLY WEDNESDAY MORNING W/40S
ELSEWHERE. THIS COLD AIR CAN BE SEEN ALREADY SHOWING UP IN NW
QUEBEC. WEDNESDAY WILL BE MUCH COOLER W/THE UPPER TROF ACROSS THE
REGION W/UPPER 50S NORTH AND WEST WHILE CENTRAL AND DOWNEAST WILL
SEE AROUND 60F OR SO DUE TO SOME DOWNSLOPING. IT WILL BE BREEZY
W/NW WINDS.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
STRONG HIGH PRESSURE WILL BUILD IN FROM THE WEST AND WEDNESDAY
NIGHT AND CREST OVER THE REGION EARLY FRIDAY KEEPING THE STATE
RELATIVELY DRY. WILL BLEND THE GFS AND ECMWF FOR POPS... QPF AND
SKY CONDITIONS. FOR WINDS HAVE USED THE MOSG25. THE SUPER BLEND
WAS USED TO POPULATE THE TEMPERATURE AND DEW POINT GRIDS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
STRONG HIGH PRESSURE WILL MOVE OFF THE EAST COAST LATE FRIDAY.
WEAK LOW PRESSURE WILL PASS TO THE SOUTH OF THE REGION SATURDAY.
HIGH PRESSURE WILL THEN BUILD IN FROM THE NORTH MONDAY. A COLD
FRONT WILL APPROACH FROM THE WEST MONDAY NIGHT AND CROSS THE
REGION TUESDAY. WILL USE THE SUPER BLEND TO POPULATE ALL GRIDS.
&&
.AVIATION /01Z WEDNESDAY THROUGH SUNDAY/...
NEAR TERM: MOSTLY VFR EARLY THIS EVENING AT THE NORTHERN
TERMINALS WITH CONDITIONS TO DROP BACK TO MVFR AND LOCAL IFR
W/THE APCHG COLD FRONT. IMPROVEMENT TO MVFR BY MID MORNING AND
VFR BY LATE IN THE DAY. KBGR AND KBHB WILL SEE VFR THROUGH
TUESDAY.
SHORT TERM: EXPECT VFR CONDITIONS WEDNESDAY NIGHT THROUGH SUNDAY.
&&
.MARINE...
NEAR TERM: SCA FOR HAZARDOUS SEAS IS IN EFFECT INCLUDING THE
INTRA-COASTAL ZONE. A SWELL BEING GENERATED FROM LEFTOVER TD ANA
IS FORECAST LIFT ACROSS THE WATERS LATER THIS EVENING INTO
WEDNESDAY. DECIDED ON HEIGHTS UP TO A RANGE OF 6-7 FT W/THE
HIGHEST WAVES OVER THE OUTER WATERS. THE INTRA-COASTAL ZONE WILL
MOST LIKELY SEE WAVES OF AROUND 5FT W/A 8-9 SECOND PERIOD. FOG
WILL BE A NUISANCE FOR NAVIGATION THROUGH TONIGHT.
FOR THE WINDS, DECIDED ATTM TO KEEP WIND GUSTS IN THE LOWER 2OS
ON WEDNESDAY W/THE NW FLOW. THE OUTER WATERS COULD SEE GUSTS HIT
25 KT FOR A BRIEF PERIOD.
SHORT TERM: HAVE BLENDED THE NAM12 AND GFS40 FOR SUSTAINED WINDS
WEDNESDAY NIGHT THROUGH FRIDAY THEN TRANSITION TO THE SUPER BLEND
WINDS. FOR WAVES: PRIMARY WAVE SYSTEM WILL BE LONG PERIOD SWELL
FROM REMNANTS OF TROPICAL DEPRESSION ANA. EXPECT 5 FEET/9-10
SECONDS WAVE HEIGHTS WEDNESDAY NIGHT SUBSIDING DURING THE DAY
THURSDAY. WILL CARRY AN SCA EARLY WEDNESDAY EVENING BUT EXPECT
SEAS TO SUBSIDE BELOW SCA LATER AT NIGHT AS THE LONG PERIOD WAVE
SYSTEM SUBSIDES. WILL USE THE NEAR SHORE WAVE MODEL THROUGH FRIDAY
THEN TRANSITION TO THE WAVE WATCH III.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL MIDNIGHT EDT
WEDNESDAY NIGHT FOR ANZ050>052.
&&
$$
NEAR TERM...CB/HEWITT
SHORT TERM...MIGNONE
LONG TERM...MIGNONE
AVIATION...CB/HEWITT/MIGNONE
MARINE...CB/HEWITT/MIGNONE
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
142 PM EDT MON MAY 11 2015
.SYNOPSIS...
VERY WARM WEATHER WILL CONTINUE TODAY UNTIL THE PASSAGE OF A
COLD FRONT OVERNIGHT. THUNDERSTORM CHANCES WILL INCREASE THIS
AFTERNOON AND TONIGHT AS THE FRONT APPROACHES.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MAIN CHANGE WAS TO TRY TO PINPOINT TIMING OF EXPECTED CONVECTIVE
ACTIVITY LATER TODAY. HRRR RUNS SEEM TO HAVE A GOOD HANDLE ON
CURRENT ACTIVITY AND HAVE BEEN FAIRLY CONSISTENT IN BRINGING
ACTIVITY TO NEAR ZZV BY 22Z AND TO THE PA/WV BORDER BY 00Z.
MIDLEVEL WINDS DO INCREASE INTO THE 40-50 KNOT RANGE AROUND 00Z IN
OHIO...AND EXPECTED INVERTED-V SOUNDINGS INDICATE SOME DOWNDRAFT
POTENTIAL AS WELL. SPC HAS OHIO OUTLOOKED IN SLIGHT RISK AREA AND
THIS LOOKS REASONABLE AS A FEW STRONG TO DAMAGING WIND GUSTS
APPEAR POSSIBLE. ADDED GUSTY WIND WORDING TO GRIDS/ZFP. MOST OTHER
CHANGES AMOUNTED TO TWEAKS. CL
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
WITH THE FRONT TIMED TO APPROACH THIS EVENING...WE WILL LOSE THE
INSTABILITY NEEDED FOR A STRONG ORGANIZED LINE OF STORMS TO
CONTINUE. ADDITIONALLY...AS THE FRONT IS NOT MUCH MORE THEN A
RIPPLE IN ISOBARS WITH ONLY WEAK COLD AIR ADVECTION BEHIND IT AND
A MINOR SHIFT IN SURFACE WINDS. I WOULD EXPECT A LINE OF SHOWERS
AND STORMS TO ROLL THROUGH WITH THIS FEATURE...BUT SEE THE
ACTIVITY WEAKENING AS IT RUSHES TO THE EAST.
UPPER TROUGH WILL PIVOT A SECONDARY FRONT...TIED TO A MUCH COOLER
AIRMASS...THROUGH THE REGION BY LATE TUESDAY MORNING. WILL NEED TO
KEEP IN THE CHANCE FOR SHOWERS AND POSSIBLY A STORM UNTIL THIS
BOUNDARY CROSSES. TEMPERATURES MAY ACTUALLY STAY ELEVATED UNTIL
THIS BOUNDARY PASSES...WITH HIGH TEMPERATURE BEING REALIZED EARLY
BEFORE A GRADUAL DECLINE IS EXPECTED. THE DOWNWARD TREND SHOULD
CONTINUE TUESDAY NIGHT AND WEDNESDAY AS THE GREAT LAKES REGION
REMAINS IN NORTHWEST FLOW.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
QUIET AND COOL BEGINNING TO THE LONG TERM PERIOD. TEMPERATURES
WILL MODERATE BY THE END OF THE WEEK AND THROUGH THE WEEKEND.
LOOKS TO BE A MORE ACTIVE WEATHER PATTERN SETTING UP FOR SATURDAY
AND SUNDAY.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
VFR CONDITIONS FOR THE MOST PART DURING THE AFTERNOON HOURS...SAVE
FOR SCATTERED TSRA THAT WILL POP UP IN INSTABILITY. HANDLED THIS
INITIAL ACTIVITY WITH VCTS FOR NOW...WILL AMEND IF THE THREAT
INCREASES AT ANY ONE TERMINAL. SW BREEZES WILL GUST TO 15-20 KNOTS
AT TIMES. EXPECT A MORE SOLID LINE OF TSRA WITH A PREFRONTAL
TROUGH...CROSSING THE AREA BETWEEN 23Z AND 06Z. MVFR/BRIEF IFR
VISIBILITIES CAN BE EXPECTED WITH THESE STORMS....WHICH COULD ALSO
CONTAIN 30-40 KNOT GUSTS AT LEAST...ESPECIALLY IN SOUTHEAST OHIO.
MAINLY SHRA AND LINGERING MVFR CIGS ARE EXPECTED AHEAD OF THE
ACTUAL FROPA...WHICH OCCURS MAINLY AFTER SUNRISE ON TUESDAY. THESE
SHRA WILL TAPER OFF BY MIDMORNING...BUT WIND WILL PICK UP
CONSIDERABLY OUT OF THE WSW...GUSTING TO BETWEEN 20 AND 30 KNOTS.
VFR WILL BECOME ESTABILISHED AREAWIDE BY THE END OF THE TAF
PERIOD.
.OUTLOOK.../MONDAY NIGHT THROUGH FRIDAY/...
THE NEXT CHANCE FOR RESTRICTIONS IS EXPECTED WITH MID WEEK
MORNING FOG AND STRATUS AS COOLER AIR SETTLES OVER THE REGION IN
THE WAKE OF THE FRONT.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1043 AM EDT MON MAY 11 2015
.SYNOPSIS...
VERY WARM WEATHER WILL CONTINUE TODAY UNTIL THE PASSAGE OF A
COLD FRONT OVERNIGHT. THUNDERSTORM CHANCES WILL INCREASE THIS
AFTERNOON AND TONIGHT AS THE FRONT APPROACHES.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MAIN CHANGE WAS TO TRY TO PINPOINT TIMING OF EXPECTED CONVECTIVE
ACTIVITY LATER TODAY. HRRR RUNS SEEM TO HAVE A GOOD HANDLE ON
CURRENT ACTIVITY AND HAVE BEEN FAIRLY CONSISTENT IN BRINGING
ACTIVITY TO NEAR ZZV BY 22Z AND TO THE PA/WV BORDER BY 00Z.
MIDLEVEL WINDS DO INCREASE INTO THE 40-50 KNOT RANGE AROUND 00Z IN
OHIO...AND EXPECTED INVERTED-V SOUNDINGS INDICATE SOME DOWNDRAFT
POTENTIAL AS WELL. SPC HAS OHIO OUTLOOKED IN SLIGHT RISK AREA AND
THIS LOOKS REASONABLE AS A FEW STRONG TO DAMAGING WIND GUSTS
APPEAR POSSIBLE. ADDED GUSTY WIND WORDING TO GRIDS/ZFP. MOST OTHER
CHANGES AMOUNTED TO TWEAKS. CL
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
WITH THE FRONT TIMED TO APPROACH THIS EVENING...WE WILL LOSE THE
INSTABILITY NEEDED FOR A STRONG ORGANIZED LINE OF STORMS TO
CONTINUE. ADDITIONALLY...AS THE FRONT IS NOT MUCH MORE THEN A
RIPPLE IN ISOBARS WITH ONLY WEAK COLD AIR ADVECTION BEHIND IT AND
A MINOR SHIFT IN SURFACE WINDS. I WOULD EXPECT A LINE OF SHOWERS
AND STORMS TO ROLL THROUGH WITH THIS FEATURE...BUT SEE THE
ACTIVITY WEAKENING AS IT RUSHES TO THE EAST.
UPPER TROUGH WILL PIVOT A SECONDARY FRONT...TIED TO A MUCH COOLER
AIRMASS...THROUGH THE REGION BY LATE TUESDAY MORNING. WILL NEED TO
KEEP IN THE CHANCE FOR SHOWERS AND POSSIBLY A STORM UNTIL THIS
BOUNDARY CROSSES. TEMPERATURES MAY ACTUALLY STAY ELEVATED UNTIL
THIS BOUNDARY PASSES...WITH HIGH TEMPERATURE BEING REALIZED EARLY
BEFORE A GRADUAL DECLINE IS EXPECTED. THE DOWNWARD TREND SHOULD
CONTINUE TUESDAY NIGHT AND WEDNESDAY AS THE GREAT LAKES REGION
REMAINS IN NORTHWEST FLOW.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
QUIET AND COOL BEGINNING TO THE LONG TERM PERIOD. TEMPERATURES
WILL MODERATE BY THE END OF THE WEEK AND THROUGH THE WEEKEND.
LOOKS TO BE A MORE ACTIVE WEATHER PATTERN SETTING UP FOR SATURDAY
AND SUNDAY.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS ARE EXPECTED THROUGH THE AFTERNOON WITH INCREASING
MID-LEVEL CLOUD COVERAGE AHEAD OF AN APPROACHING COLD FRONT.
THUNDERSTORM CHANCES WILL INCREASE THROUGH THE AFTERNOON AND LAST
THROUGH MIDNIGHT...WITH TWO PRIMARY TIMEFRAMES WHERE CHANCES WILL
BE GREATEST. FIRST BETWEEN LATE AFTERNOON AND EARLY EVENING WITH
THE PASSAGE OF A SHORTWAVE TROUGH ALOFT...AND SECOND WITH THE
PASSAGE OF A WEAK COLD FRONT SHORTLY BEFORE MIDNIGHT INTO EARLY
TUESDAY MORNING.
.OUTLOOK.../MONDAY NIGHT THROUGH FRIDAY/...
THE NEXT CHANCE FOR RESTRICTIONS IS EXPECTED WITH MID WEEK
MORNING FOG AND STRATUS AS COOLER AIR SETTLES OVER THE REGION IN
THE WAKE OF THE FRONT.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
421 PM EDT MON MAY 11 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 421 PM EDT MON MAY 11 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW THE MID LEVEL LOW THAT WAS
OVER WRN NEBRASKA/SD 24HRS AGO NOW CENTERED IN WCNTRL MN. AHEAD OF
FEATURE...WARM CONVEYOR BELT MOISTURE RIBBON EXTENDS FROM THE LWR
MISSISSIPPI VALLEY TO THE WRN GREAT LAKES. RESULT HAS BEEN NMRS SHRA
SPREADING ACROSS THE FCST AREA TODAY. A FEW TSTMS WERE NOTED THIS
MORNING OVER THE W HALF OF UPPER MI. AT THE SFC...LOW PRES LOCATED
IN CNTRL MN IS BECOMING LESS WELL-DEFINED WITH TENDENCY FOR LOW PRES
REDEVELOPMENT AT THE TRIPLE POINT FARTHER E. OCCLUDED FRONT IS
APPROACHING THE MI/WI BORDER AS OF 20Z.
AS THE WARM CONVEYOR MOISTURE RIBBON TRANSLATES E...WIDESPREAD SHRA
NOW OVER THE E HALF OF THE FCST AREA WILL ALSO SHIFT E AND OUT OF
THE AREA IN THE NEXT FEW HRS. FOG AND SOME -DZ WILL PERSIST IN THE
UPSLOPE FLOW OFF LAKE SUPERIOR INTO THE KEWEENAW AND WRN PORTIONS OF
NCNTRL UPPER MI...AND A FEW SHRA MAY DEVELOP NEAR THE OCCLUDED FRONT
WHICH SHOULD LIFT INTO OR THRU MUCH OF CNTRL AND ERN UPPER MI THIS
EVENING. OTHERWISE...AS MID LEVEL LOW OPENS UP AND UPPER TROF MOVES
E INTO THE WRN GREAT LAKES TONIGHT...DEEPER MOISTURE WILL WRAP BACK
INTO THE AREA FROM THE N AND W. AIDED BY DEEP CYCLONIC FLOW...SHRA
WILL SPREAD BACK INTO THE FCST AREA...ESPECIALLY ACROSS THE W. AS
CAA INCREASES OVERNIGHT...FCST SOUNDINGS/WETBULB ZERO HEIGHTS
SUGGEST POTENTIAL FOR SNOW TO MIX WITH THE RAIN OVER THE HIGH
TERRAIN OF THE W LATE TONIGHT.
AS TROF CONTINUES TO SHIFT E TUE...DEEP LAYER QVECTOR DIVERGENCE
OVERSPREADS THE AREA WITH HEIGHTS BEGINNING TO RISE...MORE
SUBSTANTIALLY IN THE AFTN. THIS WILL TEND TO DIMINISH THE WRAP
AROUND PCPN WITH TIME...BUT THIS WILL BE COUNTERACTED BY SHARP
CYCLONIC FLOW AND CONSIDERABLE LOW TO MID LEVEL MOISTURE THAT
LINGERS THRU THE DAY. THIS WILL RESULT IN PCPN BEING MOST PERSISTENT
IN THE AREAS THAT SEE UPSLOPING UNDER NW TO N WINDS. DOWNSLOPE AREAS
WILL SEE PCPN DIMINISH OR END. CONTINUED CAA WILL DROP 850MB TEMPS
TO -3 TO AS LOW AS -6C...AND THIS WILL RESULT IN RAIN MIXING WITH
SNOW...MAINLY OVER THE HIGHER TERRAIN OF THE W AND CNTRL. PCPN WILL
LIKELY CHANGE TO ALL SNOW AT LEAST FOR A TIME OVER THE HIGH TERRAIN
OF THE W HALF AS LOWEST 850MB TEMPS ARE FCST THERE. THAT AREA WILL
ALSO HAVE THE BEST CHANCE FOR A LITTLE SNOW ACCUMULATION ON GRASSY
SFCS. IT WILL BE AN UNSEASONABLY COLD DAY WITH TEMPS AROUND 20
DEGREES BLO NORMAL ACROSS THE W AND N WHERE TEMPS WILL STRUGGLE TO
GET MUCH ABOVE 40F. ACROSS THE SCNTRL...TEMPS MAY SNEAK INTO THE LWR
50S. BLUSTERY WINDS WILL ADD TO THE CHILL.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 255 PM EDT MON MAY 11 2015
WILL STILL HAVE SOME LINGERING MAINLY SNOW SHOWERS /WITH A FEW RAIN
SHOWERS OR AREAS OF DRIZZLE MIXED IN/ TUESDAY NIGHT OVER THE N HALF
OF UPPER MI. THE BEST CHANCE OF PRECIP WILL BE N CENTRAL AS
FAVORABLE N-NNW WINDS RESIDE THERE FROM THE SFC-850MB. TEMPERATURES
WILL BE COOLING INTO THE LOW 30S OVERNIGHT...WITH LOCATIONS OVER THE
INTERIOR W HALF FALLING INTO THE MID 20S AS WINDS BECOME NEARLY CALM
AND DRIER AIR WORKS IN AND 850MB TEMPS BEGIN TO WARM SLIGHTLY FROM -
4 TO -6C...TO AROUND -3C.
HIGH PRESSURE WILL BE STRETCHING FROM HUDSON BAY THROUGH MANITOBA
AND MN...DOWN THROUGH THE MS VALLEY AT 00Z WEDNESDAY. LOOK FOR THE
AREA OF HIGH PRESSURE TO BUILD ACROSS THE UPPER GREAT LAKES THROUGH
WEDNESDAY...WITH DRY WEATHER FIGURED INTO AT LEAST WEDNESDAY
EVENING. WAA WILL TAKE HOLD AT THE SFC ON MAINLY S WINDS OVER THE W
HALF OF THE CWA...WITH AFTERNOON HIGHS IN THE 50S FOR MOST LOCATIONS
/EXCLUDING THE COOLER N CENTRAL AND E
LAKE SUPERIOR SHORELINE/ AS 850MB TEMPS REBOUND TO AROUND 4C W TO 1C
E.
PRECIP COULD SLIDE IN AS EARLY AS LATE WEDNESDAY AFTERNOON SW /GFS
SOLUTION/. THIS WOULD BE ALONG THE SW AS AN INITIAL FRONTAL BOUNDARY
SHIFTS TO OUR N. THE MAIN CONCERN IS THAT THE LOWER LEVELS WILL BE
TOO DRY WITH THE SFC RIDGE STILL OVER MUCH OF THE AREA WITH THIS
BOUNDARY/SHORTWAVE ROUNDING THE 500MB RIDGE. WILL CONTINUE TO GO
WITH A MINIMAL PRECIP SOLUTION FOR THIS PERIOD. THE SFC HIGH WILL
SHIFT ACROSS THE ENTIRE GREAT LAKES REGION WEDNESDAY NIGHT...WITH
SLOWLY INCREASING S FLOW OVER UPPER MI PUSHING IN INCREASED MOISTURE
AS 850MB TEMPS RUMP TO AROUND 8C OVER THE SW.
THE APEX OF THE 500MB RIDGE WILL BE ACROSS THE AREA THURSDAY
AFTERNOON...WITH FCST MODELS INDICATING A NEARING EMBEDDED 500MB
TROUGH IN THE SW FLOW OVER THE N PLAINS AND W MN. THE GFS HAS A
DEEPER/WRAPPED UP SFC LOW OVER THE CENTRAL PLAINS OFF THE GFS IS NOT
QUITE A S STRONG AS THE ECMWF...ESPECIALLY THE PREVIOUS 11/06Z RUN.
THIS LEADS TO ONLY MODERATE CONFIDENCE IN THE FCST BEYOND THURSDAY.
THE DIFFERENCE SHOWS UP WELL IN THE MODEL QPF...WITH THE 11/06Z GFS
SHOWING 24HR PRECIP OF 0.75-1.45IN BY 00Z SATURDAY. THE 11/00Z ECMWF
ON THE OTHER HAND RANGES FROM LESS THAN 0.10IN ACROSS THE KEWEENAW
PENINSULA...TO 0.5IN OVER FAR S MENOMINEE CO. THIS WILL BE AS THE
SFC LOW OFF THE GFS TRACKS FROM THE CENTRAL PLAINS TO N LAKE MI BY
00Z SATURDAY. THE CANADIAN THE ECMWF KEEP A RIDGE ACROSS LAKE
SUPERIOR AND MUCH OF UPPER MI DURING THE SAME TIME PERIOD. ON A
POSITIVE NOTE...THE 11/12Z GFS CAME IN AT LEAST A LITTLE LESS
INTENSE WITH THE SFC LOW...AND DROPS ABOUT 1/2 AS MUCH PRECIP.
AN ADDITIONAL LOW DEVELOPING OFF THE N ROCKIES TOWARDS THE END OF
THE WORK WEEK WILL LIKELY BE SET UP ACROSS MT AND WY SATURDAY
MORNING...AND MOVE ACROSS THE DAKOTAS SATURDAY NIGHT...AND THE UPPER
GREAT LAKES ON MONDAY. THE 12Z RUNS HAVE BECOME MUCH MORE IN LINE
WITH THE SFC LOW TRACKING OVER E MN/FAR W LAKE SUPERIOR BY 06Z
MONDAY. THE RESULT IS AT LEAST MODERATE CONFIDENCE IN RAIN. WILL GO
WITH LIKELY PRECIP FOR SUNDAY NIGHT ACROSS MOST OF THE CWA. SO FOR
THE UPCOMING WEEKEND IT LOOKS TO BE MAINLY DRY SATURDAY...WITH WET
WEATHER APPROACHING SUNDAY AND POSSIBLY LINGERING INTO MONDAY AS THE
SFC LOW SLOWLY EDGES E OF THE CWA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 135 PM EDT MON MAY 11 2015
LOW PRES SYSTEM WILL MOVE E ACROSS THE UPPER GREAT LAKES TONIGHT AND
THEN E TO QUEBEC TUE. ABUNDANT LOW-LEVEL MOISTURE WILL GENERALLY
SUPPORT IFR TO LIFR CONDITIONS AND -SHRA AT KIWD/KCMX/KSAW THRU THIS
FCST PERIOD WITH THE LOWEST CONDITIONS OCCURRING AT TERMINALS
EXPERIENCING UPSLOPE WINDS. FOR THE REMAINDER OF THE AFTN...THE
LOWEST CONDITIONS (VLIFR) WILL OCCUR AT KCMX. SLIGHTLY DRIER AIR
TRYING TO WORK N THRU WI MAY REACH KIWD AND KSAW FOR A TIME LATE
THIS AFTN/EVENING WHICH MAY ALLOW FOR A PERIOD OF MVFR CONDITIONS.
THIS IS MORE LIKELY TO HAPPEN AT KSAW. COLDER AIR WRAPPING INTO THE
AREA BEHIND THE LOW SHOULD BE COLD ENOUGH TO RESULT IN -SHRA MIXING
WITH OR CHANGING OVER TO -SHSN TUE MORNING. CHANGE OVER TO ALL SNOW
IS MORE LIKELY TO OCCUR AT KIWD/KCMX.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 421 PM EDT MON MAY 11 2015
ONGOING MARGINAL GALES OVER THE WRN PORTION OF LAKE SUPERIOR WILL
CONTINUE TO DIMINISH...FALLING BLO GALE FORCE EARLY THIS EVENING...
AS PRES GRADIENT WEAKENS AND WINDS BACK DUE TO LOW PRES SHIFTING
ACROSS UPPER MI AND ERN LAKE SUPERIOR. ON THE BACK SIDE OF THE
LOW...NNW WINDS WILL INCREASE TO 20-30KT ACROSS CNTRL AND ERN LAKE
SUPERIOR LATE TONIGHT/TUE MORNING. MAY SEE A FEW GALE FORCE GUSTS
TUE MORNING OVER SCNTRL LAKE SUPERIOR AROUND GRANITE ISLAND DUE TO
LOCAL COASTAL CONVERGENCE. WINDS WILL DIMINISH FROM W TO E TUE
AFTN/TUE NIGHT WITH LIGHT WINDS MOSTLY UNDER 15KT TO FOLLOW FOR
WED/THU AS HIGH PRES BUILDS INTO THE UPPER LAKES WED AND THEN
LINGERS INTO THU. AS THE HIGH PRES SHIFTS E AND A WEAK LOW PRES
PASSES BY TO THE S...WINDS MAY INCREASE SOME FOR THU NIGHT/FRI
BEFORE DIMINISHING AGAIN ON SAT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 8 PM EDT /7 PM CDT/ THIS EVENING FOR LSZ162-
263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
329 PM EDT MON MAY 11 2015
LATEST UPDATE...
SYNOPSIS/SHORT TERM/LONG TERM/MARINE
.SYNOPSIS...
ISSUED AT 328 PM EDT MON MAY 11 2015
A COLD FRONT WILL COME THROUGH THE AREA TONIGHT ENDING OVER A
WEEKS WORTH OF UNSEASONABLY WARM TEMPEATURES. THERE WILL BE
SHOWERS AND A FEW THUNDERSTORMS AHEAD OF THE COLD FRONT THIS
EVENING...THEN A FEW LIGHT RAIN SHOWERS TUESDAY AS CHILLY WESTERLY
WINDS KEEP AFTERNOON TEMPERATURES IN THE 50S. SKIES WILL BECOME
PARTLY CLOUDY TUESDAY NIGHT REMAIN SO ON WEDNESDAY. ANOTHER STORM
SYSTEM WILL BRING MORE SHOWERS AND POSSIBLY THUNDERSTORMS LATER
THIS WEEK INTO THE WEEKEND. IT WILL WARM UP AGAIN BY THE END TOO.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 328 PM EDT MON MAY 11 2015
THE MAIN ISSUE IS THE THREAT FOR SEVERE STORMS (NOT MUCH) THEN THE
CHANCE FOR LIGHT RAIN SHOWERS TUESDAY AND POSSIBLE FROST TOMORROW
NIGHT.
THE LATEST RAP MODEL SHOWS THE LOW LEVEL JET CORE LIFTING
NORTHEAST FROM SOUTHWEST LOWER MICHIGAN EARLY THIS AFTERNOON TO
THE THUMB AREA BY EARLY THIS EVENING. THE MOST UNSTABLE CAPE
(OVER 500 J/KG) STAYS JUST EAST OF OUR CWA LATE THIS AFTERNOON.
WHILE THERE IS GOOD DEEP LAYER SHEAR...THE RAIN COOLED AIR OVER
MOST OF OUR CWA WILL MITIGATE MOST OF THE SEVERE WEATHER THREAT.
POSSIBLY ISOLATED DAMAING WINDS COULD HAPPEN OVER OUR EXTREME
SOUTHEAST COUNTIES EARLY THIS EVENING.
OTHERWISE THE AREA OF RAIN WILL MOVE OUT BY MID EVENING. THEN THE
DRY SLOT MOVES IN BEHIND THE COLD FRONT SO SKIES WILL CLEAR AT
LEAST PARTLY. WE THEN GET WRAP AROUND COLD AIR ADVECTION
INSTABLTLY SHOWERS (MOSTLY SPRLINKLES) TUESDAY AND IT WILL BE
BREEZY AND CHILLY WITH HIGHS ONLY IN THE 50S.
THE UPPER TROUGH MOVES OUT QUICKLY TUESDAY NIGHT ALLOWING FOR SOME
CLEARING. FROST IS POSSIBLE OVER NORTHERN AREAS WENESDAY MORNING.
.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 328 PM EDT MON MAY 11 2015
AS HIGH PRESSURE MOVES EAST THURSDAY LOW PRESSURE WILL MOVE TOWARD
THE GREAT LAKES. CONFIDENCE IS INCREASING THAT WE/LL SEE SOME
PRECIPITATION MOVE OVER THE CWA THURSDAY NIGHT AND FRIDAY. ADDED
THUNDER TO THE GRIDS FRIDAY AS LI/S FALL TO AROUND -2C AND CAPE
INCREASES TO 1K J/KG. MUCH OF THE PCPN WILL BE EAST OF THE CWA BY
SATURDAY AS THE SFC LOW MOVES AWAY. HOWEVER WE/LL KEEP LOW POPS IN
TO COVER THE UPPER TROUGH.
CHANCES FOR TSRA WILL INCREASE TOWARD THE BEGINNING OF NEXT WEEK AS
A STRONGER COLD FRONT MOVES TOWARD THE CWA. STRONG SOUTH FLOW AHEAD
OF IT WILL SEND ABUNDANT MOISTURE NORTHWARD AND CREATE SOME
INSTABILITY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 746 AM EDT MON MAY 11 2015
LIFR CONDITIONS ARE WIDESPREAD AT THE TAF SITES AT 12Z. A WARM
FRONT IS PUSHING NORTH FROM THE INTERSTATE 94 CORRIDOR WITH MUCH
IMPROVED CONDITIONS TO THE SOUTH OF IT...VFR. CONDITIONS SHOULD
CONTINUE TO IMPROVE THROUGH THE COURSE OF THE MORNING...AT LEAST
TO MVFR IF NOT VFR FOR A SHORT TIME AS THE WARM FRONT LIFTS
NORTHWARD.
THIS AFTERNOON...SHOWERS AND THUNDERSTORMS SHOULD MOVE INTO THE
AREA FROM THE SOUTHWEST. AT THIS POINT HAVE VCTS WORDING. THE
EARLY AFTERNOON SET OF TAFS MAY BE ABLE TO PROVIDE BETTER TIMING
IN REGARD TO THE PRECIPITATION. MOST LIKELY MVFR MUCH OF THE
AFTERNOON WITH CEILINGS AND POTENTIALLY VISIBILITIES.
THE SHOWERS...STORMS AND POOR AVIATION CONDITIONS SHOULD SWEEP
EAST THIS EVENING. THERE IS A CHANCE THAT MVFR CEILINGS COULD
REDEVELOP OVERNIGHT...BUT KEPT THINGS VFR AT THIS POINT.
&&
.MARINE...
ISSUED AT 328 PM EDT MON MAY 11 2015
THE STRONG WINDS BEHIND OUR SYSTEM WILL LEAD TO 4 TO 6 FOOT WAVES
AND WINDS TO 30 KNOTS BY MID MORNING TUESDAY. AS A RESULT I ISSUES
A SCA.
&&
.HYDROLOGY...
ISSUED AT 1222 PM EDT MON MAY 11 2015
ADDITIONAL RAINFALL AMOUNTS BETWEEN A QUARTER AND THREE QUARTERS OF
AN INCH WILL BE POSSIBLE MAINLY BEFORE MIDNIGHT TONIGHT. WE ARE
ISSUING ADVISORIES FOR THE SYCAMORE CREEK AT HOLT...WHICH SHOULD
CREST SHORTLY AFTER MIDNIGHT TONIGHT. CONFIDENCE IS HIGH THAT IT
WILL REMAIN BELOW FLOOD STAGE.
AFTER TONIGHT DRY CONDITIONS SHOULD PREVAIL UNTIL THURSDAY...WHEN
RAIN SHOWERS RETURN TO THE AREA. THIS SHOULD GIVE RIVER LEVELS
SOME TIME TO SUBSIDE.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY FROM 5 AM TO 6 PM EDT TUESDAY FOR
LMZ844>849.
&&
$$
SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...93
AVIATION...DUKE
HYDROLOGY...TJT
MARINE...WDM
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1224 PM EDT MON MAY 11 2015
LATEST UPDATE...
HYDRO
.SYNOPSIS...
ISSUED AT 320 AM EDT MON MAY 11 2015
SHOWERS AND THUNDERSTORMS ARE EXPECTED TODAY WITH SOME SEVERE
WEATHER POSSIBLE IN THE FORM OF DAMAGING WIND GUSTS AND PERHAPS
ISOLATED TORNADOES. A COLD FRONT MOVES IN TONIGHT BRINGING VERY
CHILLY AIR FOR TUESDAY WITH HIGHS ONLY IN THE 50S ALONG WITH GUSTY
WESTERLY WINDS. CONDITIONS SLOWLY IMPROVE WEDNESDAY AND THURSDAY
BUT MORE PRECIP IS POSSIBLE FOR LATE IN THE WEEK AND PORTIONS OF
THE WEEKEND.
&&
.UPDATE...
ISSUED AT 1115 AM EDT MON MAY 11 2015
I UPDATED THE GRIDS TO SHOW A MORE REALIST PROGRESSION OF THE
CONVECTION THAT EXPECTED TO MOVE THROUGH THE AREA THIS AFTERNOON
AHEAD OF THE COLD FRONT. I ALSO DROPPED THE FOG ADVISORY AND
REPLACED IT WITH AREAS OF FOG INTO EARLY AFTERNOON BUT FOR THE
MOST PART THE FOG IS GONE.
AS FOR THE SEVERE WEATHER THREAT... CLEARLY CLOUD COVER IS AN
ISSUE. THAT WOULD DECREASE THE THREAT FOR STRONG TO SEVERE STORMS
OVER OUR CWA THIS AFTERNOON. EVEN SO THE LATEST RAP MODEL...WHICH
IS DONE WELL WITH THE CURRENT AREA OF SHOWERS AND WHERE THE
CURRENT THUNDERSTORMS ARE...SHOWS MAX WIND SPEED CORE ON THE LOW
LEVEL JET DEVELOPING OVER WRN IN AND SOUTHWEST LWR MI BY NOON BUT
AT THAT POINT WINDS ARE MOSTLY UNDER 35 KNOTS. BY 4 PM THE RAP 14Z
MODEL SHOWS A CORE OF 40 KNOT WINDS ON THE LOW LEVEL JET NEAR JXN
MOVING NORTHEAST...REACHING THE FNT AREA BY EARLY EVENING. AT THE
SAME TIME THE ENTRANCE REGION TO A 110 KNOT 300 MB JET IS MOVING
NORTH NORTHEAST ACROSS LAKE MICHIGAN. THE PUTS MOST OF SOUTHWEST
MICHIGAN IN A FAVORABLE PLACE FOR STRONG TO SEVERE THUNDERSTORMS.
THE MOST UNSTABLE CAPE (OVER 500 J/KG) STAYS SOUTH OF A LINE FROM
AZO TO LAN TO FNT. THIS TELLS ME THE THREAT FOR STRONG TO SEVERE
STORMS IS MOSTLY IN THE I-69 AREA (MORE OR LESS) DURING THE MID
AFTERNOON. ELSESWHERE WILL LIKELY SEE SHOWERS AND
THUNDERSTORMS... WITH A LESSER THREAT FOR STRONG TO SEVERE STORMS.
ALSO THIS TELLS ME THE GREATEST THREAT IS FOR DAMAGING WINDS SINCE
THE CAPE IS NOT ALL THAT GREAT IN THE -10 TO -30C RANGE ON THE
LATEST RAP MODEL SOUNDINGS NEAR JXN AND LAN.
UPDATE ISSUED AT 626 AM EDT MON MAY 11 2015
WILL BE ISSUING A DENSE FOG ADVISORY SHORTLY FOR THE TWO ROWS OF
COUNTIES NORTH OF THE I94 ROW. FEEL THAT CONDITIONS ARE IMPROVING
AND WILL CONTINUE TO IMPROVE ALONG I94...SO LEFT THAT ROW OUT OF
THE DENSE FOG ADVISORY FOR THE TIME BEING. THE DENSE FOG ADVISORY
WILL INCLUDE HOLLAND...GRAND RAPIDS...LANSING AND HASTINGS. THE
FOG IS MOST THICK JUST NORTH OF THE WARM FRONT WHICH IS LIFTING
NORTH. THE WARM FRONT AT 600AM WAS LOCATED ALONG I94 LIFTING
NORTH. OB SITES IN THE FAR SOUTHERN ROW OF COUNTIES ALONG THE
MI/IN LINE HAVE IMPROVED SUBSTANTIALLY WITH THIS TREND MOVING
NORTH. THE ADVISORY WILL RUN THROUGH 11AM.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 320 AM EDT MON MAY 11 2015
FORECAST CONCERNS DEAL WITH THE THREAT FOR STRONG TO SEVERE THUNDERSTORMS
PRIMARILY THIS AFTERNOON AND EVENING. OVERALL...THERE LOOKS TO BE A MAIN WINDOW
OF OPPORTUNITY FROM 17Z TO 00Z FOR ANY SEVERE WEATHER...WITH THE PRIMARY THREAT
BEING DAMAGING WIND GUSTS AND A SECONDARY CONCERN BEING ISOLATED TORNADOES.
MANY INGREDIENTS ARE COMING TOGETHER TODAY TO SUPPORT THE CONTINUED THREAT FOR
SEVERE THUNDERSTORMS IN SPITE OF AN ENVIRONMENT THAT WILL FEATURE ONLY MODEST
CAPE. GOOD POSITIONING WITH RESPECT TO THE UPPER LEVEL JET (STRONGER DIVERGENCE
SHOWN TO OVERSPREAD THE SOUTHERN AND EASTERN CWA BY 18Z) ALONG WITH MID LEVEL
VORT LOBES AND A STRONG LLJ OF 50 KTS ACROSS NORTHERN INDIANA ARE THE MAIN
SYNOPTIC FEATURES OF NOTE. SPEAKING OF THE LLJ...THERE LOOKS TO BE DECENT WIND
CONVERGENCE AT THE NOSE OF THE JET ACROSS SW AND S CENTRAL LOWER MI. MOISTURE
POOLING AND CONVECTIVE DEVELOPMENT LOOK LIKELY ACROSS A GOOD PORTION OF THE
CWA...INCLUDING BUT NOT LIMITED TO WHERE THE SLIGHT RISK AREA IS OUTLINED
FOR TODAY.
WHILE SFC BASED CAPE WILL BE REALIZED AS THE WARM FRONT PUSHES NORTH TODAY...IT
WILL NOT BE SUBSTANTIAL...ONLY ON THE ORDER OF A FEW HUNDRED JOULES/KG MAINLY
FROM I-96 TO THE SOUTH. HOWEVER...COMPENSATING FOR THE MARGINAL INSTABILITY
WILL BE STRONG LOW LEVEL WIND SHEAR AND ELEVATED STORM RELATIVE
HELICITY...WHICH INTRODUCES A THREAT FOR ISOLATED TORNADOES. GFS BUFKIT
SOUNDING FOR AZO AT 18Z SHOWS 0-2KM SHEAR OF AROUND 45 KTS AND 0-1KM SRH OF 235
M2/S2. THE SPC SREF SIG TOR PARAMETER SHOWS A 30% PROBABILITY OF >=1 FOR OUR
SOUTH CENTRAL CWA.
THE CONVECTION ALLOWING MODELS SUPPORT A LINEAR LINE BEING THE PRIMARY
CONVECTIVE MODE...WITH SOME SUGGESTION THAT A FEW DISCRETE CELLS COULD FIRE
AHEAD OF THE LINE ESPECIALLY EAST OF A AZO TO LAN LINE. THE NSSL WRF AND HRRR
BOTH SUGGEST A LINEAR LINE OF STORMS MOVING FROM NORTHERN INDIANA INTO SW LOWER
MI LATE MORNING/EARLY AFTERNOON...AND PROGRESSING EAST QUITE RAPIDLY. THIS LINE
OF STORMS WILL LIKELY BE PRE-FRONTAL WITH A MORE NARROW LINE OF CONVECTION
FOLLOWING FOR LATE IN THE AFTERNOON AND EARLY EVENING...MARKING THE ARRIVAL OF
THE COLD FRONT.
CHILLY TEMPS ON TUESDAY IN THE MIDST OF CAA WILL MAKE FOR A RATHER
FALL-LIKE DAY. GUSTY WINDS ARE FORECAST TO BE 20 TO 30 MPH OR
PERHAPS GREATER AT TIMES...MAKING IT FEEL EVEN COLDER THAN THE
50S. CONDITIONS SLOWLY IMPROVE WEDNESDAY AND THURSDAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 320 AM EDT MON MAY 11 2015
EXTENDED PERIOD LOOKS TO FEATURE NEAR TO ABOVE NORMAL TEMPERATURES
AND POTENTIALLY WET WEATHER. THE UPPER PATTERN WILL START WITH
RIDGING IN PLACE MID WEEK...WHICH WILL TREND TO A DEEP SOUTHWEST
FLOW LATE IN THE WORK WEEK AND INTO NEXT WEEKEND.
TWO MAIN WEATHER FEATURES TO KEEP AN EYE ON. FIRST IS A SHORTWAVE
THAT MOVES THROUGH THE REGION THURSDAY NIGHT AND FRIDAY. HAVE
SHOWERS IN THE FORECAST BOTH PERIODS. AT THIS POINT JUST CHANCE
POPS...BUT COULD SEE NEEDING TO BUMP THIS UP WITH TIME.
THE NEXT ITEM OF NOTE WILL BE OVER THE WEEKEND AS A WARM FRONT SETS
UP OVER THE GREAT LAKES AHEAD OF A LOW IN THE PLAINS. WE COULD SEE
PERIODS OF SHOWERS AND STORMS DURING THIS TIME FRAME.
HIGHS WILL START THE PERIOD IN THE 60S ON THURSDAY...BUT WARM INTO
THE 70S OVER THE WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 746 AM EDT MON MAY 11 2015
LIFR CONDITIONS ARE WIDESPREAD AT THE TAF SITES AT 12Z. A WARM
FRONT IS PUSHING NORTH FROM THE INTERSTATE 94 CORRIDOR WITH MUCH
IMPROVED CONDITIONS TO THE SOUTH OF IT...VFR. CONDITIONS SHOULD
CONTINUE TO IMPROVE THROUGH THE COURSE OF THE MORNING...AT LEAST
TO MVFR IF NOT VFR FOR A SHORT TIME AS THE WARM FRONT LIFTS
NORTHWARD.
THIS AFTERNOON...SHOWERS AND THUNDERSTORMS SHOULD MOVE INTO THE
AREA FROM THE SOUTHWEST. AT THIS POINT HAVE VCTS WORDING. THE
EARLY AFTERNOON SET OF TAFS MAY BE ABLE TO PROVIDE BETTER TIMING
IN REGARD TO THE PRECIPITATION. MOST LIKELY MVFR MUCH OF THE
AFTERNOON WITH CEILINGS AND POTENTIALLY VISIBILITIES.
THE SHOWERS...STORMS AND POOR AVIATION CONDITIONS SHOULD SWEEP
EAST THIS EVENING. THERE IS A CHANCE THAT MVFR CEILINGS COULD
REDEVELOP OVERNIGHT...BUT KEPT THINGS VFR AT THIS POINT.
&&
.MARINE...
ISSUED AT 1115 AM EDT MON MAY 11 2015
LOOKING AT WEB CAMS FOG DOES NOT SEEM TO BE MUCH OF AN ISSUE OVER
THE NEAR SHORE SO I DISCONTINUED THE DENSE FOG ADVISORY.
&&
.HYDROLOGY...
ISSUED AT 1222 PM EDT MON MAY 11 2015
ADDITIONAL RAINFALL AMOUNTS BETWEEN A QUARTER AND THREE QUARTERS OF
AN INCH WILL BE POSSIBLE MAINLY BEFORE MIDNIGHT TONIGHT. WE ARE
ISSUING ADVISORIES FOR THE SYCAMORE CREEK AT HOLT...WHICH SHOULD
CREST SHORTLY AFTER MIDNIGHT TONIGHT. CONFIDENCE IS HIGH THAT IT
WILL REMAIN BELOW FLOOD STAGE.
AFTER TONIGHT DRY CONDITIONS SHOULD PREVAIL UNTIL THURSDAY...WHEN
RAIN SHOWERS RETURN TO THE AREA. THIS SHOULD GIVE RIVER LEVELS
SOME TIME TO SUBSIDE.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...WDM
SYNOPSIS...HOVING
SHORT TERM...HOVING
LONG TERM...DUKE
AVIATION...DUKE
HYDROLOGY...TJT
MARINE...WDM
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1115 AM EDT MON MAY 11 2015
LATEST UPDATE...
UPDATE/MARINE
.SYNOPSIS...
ISSUED AT 320 AM EDT MON MAY 11 2015
SHOWERS AND THUNDERSTORMS ARE EXPECTED TODAY WITH SOME SEVERE
WEATHER POSSIBLE IN THE FORM OF DAMAGING WIND GUSTS AND PERHAPS
ISOLATED TORNADOES. A COLD FRONT MOVES IN TONIGHT BRINGING VERY
CHILLY AIR FOR TUESDAY WITH HIGHS ONLY IN THE 50S ALONG WITH GUSTY
WESTERLY WINDS. CONDITIONS SLOWLY IMPROVE WEDNESDAY AND THURSDAY
BUT MORE PRECIP IS POSSIBLE FOR LATE IN THE WEEK AND PORTIONS OF
THE WEEKEND.
&&
.UPDATE...
ISSUED AT 1115 AM EDT MON MAY 11 2015
I UPDATED THE GRIDS TO SHOW A MORE REALIST PROGRESSION OF THE
CONVECTION THAT EXPECTED TO MOVE THROUGH THE AREA THIS AFTERNOON
AHEAD OF THE COLD FRONT. I ALSO DROPPED THE FOG ADVISORY AND
REPLACED IT WITH AREAS OF FOG INTO EARLY AFTERNOON BUT FOR THE
MOST PART THE FOG IS GONE.
AS FOR THE SEVERE WEATHER THREAT... CLEARLY CLOUD COVER IS AN
ISSUE. THAT WOULD DECREASE THE THREAT FOR STRONG TO SEVERE STORMS
OVER OUR CWA THIS AFTERNOON. EVEN SO THE LATEST RAP MODEL...WHICH
IS DONE WELL WITH THE CURRENT AREA OF SHOWERS AND WHERE THE
CURRENT THUNDERSTORMS ARE...SHOWS MAX WIND SPEED CORE ON THE LOW
LEVEL JET DEVELOPING OVER WRN IN AND SOUTHWEST LWR MI BY NOON BUT
AT THAT POINT WINDS ARE MOSTLY UNDER 35 KNOTS. BY 4 PM THE RAP 14Z
MODEL SHOWS A CORE OF 40 KNOT WINDS ON THE LOW LEVEL JET NEAR JXN
MOVING NORTHEAST...REACHING THE FNT AREA BY EARLY EVENING. AT THE
SAME TIME THE ENTRANCE REGION TO A 110 KNOT 300 MB JET IS MOVING
NORTH NORTHEAST ACROSS LAKE MICHIGAN. THE PUTS MOST OF SOUTHWEST
MICHIGAN IN A FAVORABLE PLACE FOR STRONG TO SEVERE THUNDERSTORMS.
THE MOST UNSTABLE CAPE (OVER 500 J/KG) STAYS SOUTH OF A LINE FROM
AZO TO LAN TO FNT. THIS TELLS ME THE THREAT FOR STRONG TO SEVERE
STORMS IS MOSTLY IN THE I-69 AREA (MORE OR LESS) DURING THE MID
AFTERNOON. ELSESWHERE WILL LIKELY SEE SHOWERS AND
THUNDERSTORMS... WITH A LESSER THREAT FOR STRONG TO SEVERE STORMS.
ALSO THIS TELLS ME THE GREATEST THREAT IS FOR DAMAGING WINDS SINCE
THE CAPE IS NOT ALL THAT GREAT IN THE -10 TO -30C RANGE ON THE
LATEST RAP MODEL SOUNDINGS NEAR JXN AND LAN.
UPDATE ISSUED AT 626 AM EDT MON MAY 11 2015
WILL BE ISSUING A DENSE FOG ADVISORY SHORTLY FOR THE TWO ROWS OF
COUNTIES NORTH OF THE I94 ROW. FEEL THAT CONDITIONS ARE IMPROVING
AND WILL CONTINUE TO IMPROVE ALONG I94...SO LEFT THAT ROW OUT OF
THE DENSE FOG ADVISORY FOR THE TIME BEING. THE DENSE FOG ADVISORY
WILL INCLUDE HOLLAND...GRAND RAPIDS...LANSING AND HASTINGS. THE
FOG IS MOST THICK JUST NORTH OF THE WARM FRONT WHICH IS LIFTING
NORTH. THE WARM FRONT AT 600AM WAS LOCATED ALONG I94 LIFTING
NORTH. OB SITES IN THE FAR SOUTHERN ROW OF COUNTIES ALONG THE
MI/IN LINE HAVE IMPROVED SUBSTANTIALLY WITH THIS TREND MOVING
NORTH. THE ADVISORY WILL RUN THROUGH 11AM.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 320 AM EDT MON MAY 11 2015
FORECAST CONCERNS DEAL WITH THE THREAT FOR STRONG TO SEVERE THUNDERSTORMS
PRIMARILY THIS AFTERNOON AND EVENING. OVERALL...THERE LOOKS TO BE A MAIN WINDOW
OF OPPORTUNITY FROM 17Z TO 00Z FOR ANY SEVERE WEATHER...WITH THE PRIMARY THREAT
BEING DAMAGING WIND GUSTS AND A SECONDARY CONCERN BEING ISOLATED TORNADOES.
MANY INGREDIENTS ARE COMING TOGETHER TODAY TO SUPPORT THE CONTINUED THREAT FOR
SEVERE THUNDERSTORMS IN SPITE OF AN ENVIRONMENT THAT WILL FEATURE ONLY MODEST
CAPE. GOOD POSITIONING WITH RESPECT TO THE UPPER LEVEL JET (STRONGER DIVERGENCE
SHOWN TO OVERSPREAD THE SOUTHERN AND EASTERN CWA BY 18Z) ALONG WITH MID LEVEL
VORT LOBES AND A STRONG LLJ OF 50 KTS ACROSS NORTHERN INDIANA ARE THE MAIN
SYNOPTIC FEATURES OF NOTE. SPEAKING OF THE LLJ...THERE LOOKS TO BE DECENT WIND
CONVERGENCE AT THE NOSE OF THE JET ACROSS SW AND S CENTRAL LOWER MI. MOISTURE
POOLING AND CONVECTIVE DEVELOPMENT LOOK LIKELY ACROSS A GOOD PORTION OF THE
CWA...INCLUDING BUT NOT LIMITED TO WHERE THE SLIGHT RISK AREA IS OUTLINED
FOR TODAY.
WHILE SFC BASED CAPE WILL BE REALIZED AS THE WARM FRONT PUSHES NORTH TODAY...IT
WILL NOT BE SUBSTANTIAL...ONLY ON THE ORDER OF A FEW HUNDRED JOULES/KG MAINLY
FROM I-96 TO THE SOUTH. HOWEVER...COMPENSATING FOR THE MARGINAL INSTABILITY
WILL BE STRONG LOW LEVEL WIND SHEAR AND ELEVATED STORM RELATIVE
HELICITY...WHICH INTRODUCES A THREAT FOR ISOLATED TORNADOES. GFS BUFKIT
SOUNDING FOR AZO AT 18Z SHOWS 0-2KM SHEAR OF AROUND 45 KTS AND 0-1KM SRH OF 235
M2/S2. THE SPC SREF SIG TOR PARAMETER SHOWS A 30% PROBABILITY OF >=1 FOR OUR
SOUTH CENTRAL CWA.
THE CONVECTION ALLOWING MODELS SUPPORT A LINEAR LINE BEING THE PRIMARY
CONVECTIVE MODE...WITH SOME SUGGESTION THAT A FEW DISCRETE CELLS COULD FIRE
AHEAD OF THE LINE ESPECIALLY EAST OF A AZO TO LAN LINE. THE NSSL WRF AND HRRR
BOTH SUGGEST A LINEAR LINE OF STORMS MOVING FROM NORTHERN INDIANA INTO SW LOWER
MI LATE MORNING/EARLY AFTERNOON...AND PROGRESSING EAST QUITE RAPIDLY. THIS LINE
OF STORMS WILL LIKELY BE PRE-FRONTAL WITH A MORE NARROW LINE OF CONVECTION
FOLLOWING FOR LATE IN THE AFTERNOON AND EARLY EVENING...MARKING THE ARRIVAL OF
THE COLD FRONT.
CHILLY TEMPS ON TUESDAY IN THE MIDST OF CAA WILL MAKE FOR A RATHER
FALL-LIKE DAY. GUSTY WINDS ARE FORECAST TO BE 20 TO 30 MPH OR
PERHAPS GREATER AT TIMES...MAKING IT FEEL EVEN COLDER THAN THE
50S. CONDITIONS SLOWLY IMPROVE WEDNESDAY AND THURSDAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 320 AM EDT MON MAY 11 2015
EXTENDED PERIOD LOOKS TO FEATURE NEAR TO ABOVE NORMAL TEMPERATURES
AND POTENTIALLY WET WEATHER. THE UPPER PATTERN WILL START WITH
RIDGING IN PLACE MID WEEK...WHICH WILL TREND TO A DEEP SOUTHWEST
FLOW LATE IN THE WORK WEEK AND INTO NEXT WEEKEND.
TWO MAIN WEATHER FEATURES TO KEEP AN EYE ON. FIRST IS A SHORTWAVE
THAT MOVES THROUGH THE REGION THURSDAY NIGHT AND FRIDAY. HAVE
SHOWERS IN THE FORECAST BOTH PERIODS. AT THIS POINT JUST CHANCE
POPS...BUT COULD SEE NEEDING TO BUMP THIS UP WITH TIME.
THE NEXT ITEM OF NOTE WILL BE OVER THE WEEKEND AS A WARM FRONT SETS
UP OVER THE GREAT LAKES AHEAD OF A LOW IN THE PLAINS. WE COULD SEE
PERIODS OF SHOWERS AND STORMS DURING THIS TIME FRAME.
HIGHS WILL START THE PERIOD IN THE 60S ON THURSDAY...BUT WARM INTO
THE 70S OVER THE WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 746 AM EDT MON MAY 11 2015
LIFR CONDITIONS ARE WIDESPREAD AT THE TAF SITES AT 12Z. A WARM
FRONT IS PUSHING NORTH FROM THE INTERSTATE 94 CORRIDOR WITH MUCH
IMPROVED CONDITIONS TO THE SOUTH OF IT...VFR. CONDITIONS SHOULD
CONTINUE TO IMPROVE THROUGH THE COURSE OF THE MORNING...AT LEAST
TO MVFR IF NOT VFR FOR A SHORT TIME AS THE WARM FRONT LIFTS
NORTHWARD.
THIS AFTERNOON...SHOWERS AND THUNDERSTORMS SHOULD MOVE INTO THE
AREA FROM THE SOUTHWEST. AT THIS POINT HAVE VCTS WORDING. THE
EARLY AFTERNOON SET OF TAFS MAY BE ABLE TO PROVIDE BETTER TIMING
IN REGARD TO THE PRECIPITATION. MOST LIKELY MVFR MUCH OF THE
AFTERNOON WITH CEILINGS AND POTENTIALLY VISIBILITIES.
THE SHOWERS...STORMS AND POOR AVIATION CONDITIONS SHOULD SWEEP
EAST THIS EVENING. THERE IS A CHANCE THAT MVFR CEILINGS COULD
REDEVELOP OVERNIGHT...BUT KEPT THINGS VFR AT THIS POINT.
&&
.MARINE...
ISSUED AT 1115 AM EDT MON MAY 11 2015
LOOKING AT WEB CAMS FOG DOES NOT SEEM TO BE MUCH OF AN ISSUE OVER
THE NEAR SHORE SO I DISCONTINUED THE DENSE FOG ADVISORY.
&&
.HYDROLOGY...
ISSUED AT 1242 PM EDT SUN MAY 10 2015
MOST AREAS HAVE RECEIVED BETWEEN 1 AND 1.5 INCHES OF RAIN SINCE
THURSDAY. THIS HAS BEEN STEADY ENOUGH TO KEEP RIVER RESPONSE QUITE
GENTLE SO FAR. THERE IS STILL A FAIR CUSHION BEFORE BANKFULL IS
REACHED AT MOST LOCATIONS.
AN ADDITIONAL 0.5 TO 0.75 INCHES OF RAIN IS EXPECTED THROUGH MONDAY
EVENING. AFTER THIS DRY CONDITIONS SHOULD PREVAIL THE REST OF THE
WORK WEEK. THIS WILL RESULT IN ADDITIONAL MODEST WITHIN BANK RISES
FOR MOST RIVERS AND STREAMS. THE AREAS MOST VULNERABLE TO
SIGNIFICANT RISES UNDER THE HEAVIEST RAIN INCLUDE THE GRAND RIVER AT
JACKSON AND THE HEADWATERS OF THE KALAMAZOO RIVER.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...WDM
SYNOPSIS...HOVING
SHORT TERM...HOVING
LONG TERM...DUKE
AVIATION...DUKE
HYDROLOGY...TJT
MARINE...WDM
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
416 AM EDT MON MAY 11 2015
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 417 PM EDT SUN MAY 10 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW THE WELL-DEFINED MID LEVEL
LOW THAT WAS OVER THE SRN ROCKIES YESTERDAY NOW LIFTING N ACROSS WRN
NEBRASKA/WRN SD. ONE WEAK LEAD SHORTWAVE THAT WAS OVER THE SRN
PLAINS YESTERDAY HAS MOVED NE THRU LWR MI TODAY...SPREADING SHRA AND
A FEW TSRA ACROSS LWR MI. CLOSER TO HOME...WEBCAMS INDICATED SOME
PATCHY -DZ THIS MORNING OVER ERN PARTS OF THE FCST AREA AS LOW
CLOUDS SPREAD BACK INTO MUCH OF UPPER MI. OTHERWISE...NO PCPN HAS
OCCURRED TODAY. CLOUDS HAVE DOMINATED MOST OF THE FCST AREA.
HOWEVER...MUCH OF THE WRN FCST AREA HAS BECOME MOSTLY SUNNY RECENTLY
AS THE LOW CLOUDS HAVE DISSIPATED IN THAT AREA.
TONIGHT AND MON...MID LEVEL LOW MOVING INTO SD WILL GRADUALLY OPEN
UP AS IT DRIFTS INTO MN. ON THIS TRACK...THE STRONGEST DEEP LAYER
FORCING (SHOWN NICELY BY QVECTORS) AND STRONGEST ISENTROPIC ASCENT
WILL FOCUS INTO NRN MN. FARTHER E...A WEAKER EASTWARD EXTENSION OF
DEEP LAYER FORCING COMBINED WITH A RIBBON OF REASONABLY STRONG
ISENTROPIC ASCENT LIFTING NE ACROSS THE AREA SHOULD SUPPORT A PERIOD
OF SHRA...MAINLY LATE TONIGHT THRU MON MORNING. THERE IS VERY LITTLE
TO NO INSTABILITY NOTED ACCOMPANYING THIS BAND OF FORCING/SHRA...SO
THUNDER POTENTIAL IS VERY LIMITED. WILL MAINTAIN A SCHC MENTION ONLY
OVER THE FAR SCNTRL...CLOSER TO SOMEWHAT BETTER ELEVATED INSTABILITY
TO THE S. MID LEVEL DRYING PUSHES INTO THE FCST AREA DURING THE DAY
MON...FOLLOWING THE RIBBON OF ISENTROPIC ASCENT. THIS SHOULD RESULT
IN A TRANSITION TO MAINLY DRY WEATHER OVER MOST OF THE AREA. BETTER
CHC OF LINGERING ISOLD/SCT -SHRA IN THE AFTN WILL BE OVER THE N AND
E. THAT SAID...SEEMS MORE LIKELY THAT WHERE UPSLOPE FLOW PERSISTS...
LINGERING LOW-LEVEL MOISTURE MAY RESULT IN SOME -DZ AND UPSLOPE
FOG...MAINLY ACROSS THE KEWEENAW AND NCNTRL UPPER MI. COMBINATION OF
RAIN AND HIGHER DWPTS SPREADING N OVER LAKE MI WILL LIKELY MEAN FOG
SPREADING UP LAKE MI AND AFFECTING AREAS MAINLY E OF KESC AS WELL.
LATER IN THE AFTN...BROADENING SFC LOW/OCCLUDED FRONT MAY SLIP INTO
THE SRN FCST AREA. GFS/NAM SHOW SOME LOW-LEVEL INSTABILITY (FEW
HUNDRED J/KG) NEAR THIS FEATURE. COULD SPARK ISOLD TSRA LATE...BUT
CONFIDENCE IN THAT OCCURRING IS VERY LOW. AS FOR TEMPS...THERE IS
BIG BUST POTENTIAL WITH MAX TEMPS ON MON. IF THE OCCLUDED FRONT
LIFTS INTO SRN UPPER MI AND CLOUDS BREAK...TEMPS COULD QUICKLY RISE
WELL INTO THE 60S. SOME OF THE BIAS CORRECTED GUIDANCE HAS MAX TEMPS
UP AROUND 70F NEAR THE MI/WI BORDER. FOR NOW...HAVE MAX TEMPS NEAR
60F OVER THE SCNTRL. TO THE N...WHERE FLOW REMAINS UPSLOPE OFF LAKE
SUPERIOR...TEMPS SHOULD NOT RISE HIGHER THAN THE LWR 40S.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 414 AM EDT MON MAY 11 2015
MAIN FCST CONCERNS IN THE MEDIUM/EXTENDED RANGE WL FOCUS ON
POPS/QPF/PTYPE ON TUE AS COLDER AIR MOVES INTO THE UPR LKS IN CYC
NNW FLOW LEFT IN THE WAKE OF DEPARTING SFC LO TO THE E. AFTER A
DRYING TREND ON TUE NGT/WED ASSOCIATED WITH TRAILING HI PRES...
FOCUS FOR THE EXTENDED PERIOD WILL SHIFT TO POPS IN WAA REGIME BTWN
THIS DEPARTING HI TO THE E AND FALLING MSLP IN THE PLAINS. TEMPS
THRU WED WL RUN BLO NORMAL BUT THEN RECOVER BACK TO AVERAGE BY THE
END OF THE WEEK.
TUE...AS THE SHRTWV EXITS TO THE E...DNVA/DEEP LYR QVECTOR DVGC
UNDER RISING HGTS IN ITS WAKE AND WEAKENING LO PRES TROF/CYC FLOW WL
DIMINISH THE POPS DESPITE LINGERING DEEP MSTR. LINGERING SHOWERS WL
BE MOST PERSISTENT IN THE UPSLOPE AREAS OVER THE NRN TIER IMPACTED
BY THE N FLOW BTWN THE DEPARTING SFC LO AND APRCHG HI PRES IN MN.
THE ARRIVAL OF COLDER AIR WITH H85 TEMPS AS LO AS -5 TO -6C WL ALLOW
THE PCPN TO MIX WITH SN ON TUE ESPECIALLY OVER THE HIER TERRAIN OF
THE NCNTRL AND W. BEST CHC FOR SOME ACCUMULATING SN WL BE ON
GRASSY SFCS IN THE MRNG OVER THE W...WHERE SUFFICIENTLY COLD AIR WL
ARRIVE EARLY ENUF BEFORE DAYTIME INSOLATION CAN HAVE A BIG IMPACT
AND THERE WL BE SOME LINGERING DYNAMIC SUPPORT/SHARPER CYC FLOW
EARLY IN THE DAY. DOWNSLOPE WIND COMPONENT WL HAVE A NEGATIVE IMPACT
ON POPS OVER THE SCENTRAL. MAX TEMPS WL BE UP TO 20 DEGREES BLO
NORMAL WITH READINGS NOT RISING MUCH ABOVE 40 OVER THE HIER TERRAIN
AND NEAR LK SUP.
TUE NGT...AS THE LO EXITS TO THE E...SFC HI PRES/LLVL ACYC FLOW ARE
PROGGED TO MOVE INTO THE CWA UNDER PERSISTENT HGT RISES/DNVA/DEEP
LYR DRYING AND END LINGERING PCPN AFTER 06Z. IF SKIES CLR...MIN
TEMPS ARE LIKELY TO FALL WELL BLO 32 OVER THE INTERIOR W HALF CLOSER
TO THE INCOMING HI...WHERE WINDS WL BE LIGHTER LONGER AND PWAT WL
FALL CLOSE TO 0.25-0.30 INCH BY 12Z WED. TENDED TOWARD THE LO END OF
GUIDANCE FOR MIN TEMPS IN THIS AREA WITH EXPECTATION THIS DRYING WL
RESULT IN CLRG.
WED...AS UPR RDG BLDS INTO THE WRN GRT LKS...SFC HI PRES IS FCST TO
MOVE NEARLY OVHD. ALTHOUGH SOME MID/HI CLDS ARE FCST TO STREAM INTO
THE W DURING THE AFTN...H85 TEMPS REBOUNDING TO 1 TO 2C WL SUPPORT
MAX TEMPS NEAR 60 AWAY FM THE MODERATING INFLUENCE OF THE LKS. WITH
A LIGHT N WIND AT H925...THE MODERATION OFF LK SUP WL BE MOST SGNFT.
WED NGT THRU FRI...AS THE SFC HI PRES SHIFTS TO THE E AND A RETURN
SLY FLOW/WAA REGIME SETS UP TO THE NE OF AN H85 WARM FNT IN THE NRN
PLAINS/UPR MS RIVER VALLEY...THE MEDIUM RANGE MODELS SHOW INCRSG MID
LVL MSTR AND GENERATE AT LEAST SOME QPF NEAR/OVER UPR MI. BUT THERE
ARE TIMING/PLACEMENT DIFFERENCES AMONG THE MODELS...MAINLY DUE TO
THE VARIABILITY ON THE FCST TRACK OF SHRTWVS PROGGED TO RIDE THRU
THE UPR RDG OVER THE WRN LKS AS WELL AS THE IMPACT OF NEAR SFC DRY
AIR. GIVEN THE SPRAWLING SFC HI PRES/LLVL DRY AIR IN PLACE ON WED
NGT...TENDED TO REJECT THE MORE AGGRESSIVE 12Z ECMWF FCST OF PCPN
SPREADING INTO THE ERN ZNS SO QUICKLY. THE 00Z CNDN MODEL IS
GENERALLY THE DRIEST...WHILE THERE IS GOOD AGREEMENT AMONG THE 00Z
GFS/12Z ECMWF ON A MORE WIDESPREAD RA FOR THU NGT INTO FRI AS A MORE
WELL DEFINED SHRTWV/AREA OF UPR DVGC ENHANCED BY PLACEMENT OF CWA IN
RRQ OF UPR JET IN SE CANADA IMPACT THE AREA AND INTERACT WITH PWAT
AOA AN INCH DRIVEN INTO THE UPR LKS BY DEEP SLY FLOW AHEAD OF THE
APRCHG DISTURBANCE. A QUICK LOOK AT THE 00Z ECMWF INDICATES THIS
DISTURBANCE MAY TAKE A BIT MORE SRN TRACK...WHICH WOULD LESSEN THE
POTENTIAL FOR SGNFT PCPN OVER UPR MI.
SAT/SUN...WHILE THERE IS LIKELY TO BE A DRYING TREND IN THE WAKE OF
DISTURBANCE RESPONSIBLE FOR HIER POPS ON THU NGT/FRI...THE LONGER
RANGE MODELS INDICATE ANOTHER SHRTWV WL RIDE TOWARD THE UPR LKS THIS
COMING WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 138 AM EDT MON MAY 11 2015
CHALLENGING FCST SHAPING UP OVER THE NEXT 24HRS. LOW PRES SYSTEM
MOVING NE THRU THE PLAINS WILL SWING SHRA NE INTO THE UPPER
LAKES...MAINLY LATE IN THE OVERNIGHT HOURS INTO THROUGH MIDDAY
TODAY. ALL SITES SHOULD STAY MVFR REST OF THE NIGHT BUT AS -SHRA
ARRIVE...EXPECT A TREND DOWN TO IFR THIS MORNING AT ALL TERMINALS.
UPSLOPE E-NE FLOW WILL LIKELY RESULT IN LIFR CONDITIONS DEVELOPING AT
KCMX/KSAW BY LATE THIS MORNING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 417 PM EDT SUN MAY 10 2015
TIGHT PRES GRADIENT WILL BE OVER LAKE SUPERIOR TONIGHT THRU MUCH OF
MON AS HIGH PRES REMAINS NEARLY STATIONARY...CENTERED OVER FAR NRN
ONTARIO...AND LOW PRES MOVES FROM NEBRASKA TO FAR NRN WI. AS A
RESULT BRISK NE TO E WINDS OF 15-30KT WILL BE THE RULE ACROSS LAKE
SUPERIOR. THE STRONGEST WINDS (GALE FORCE) WILL BE OVER THE WRN
PORTION OF THE LAKE WHERE COASTAL CONVERGENCE/FUNNELING AND
PERSISTENT PRES FALLS TO THE SW THRU AT LEAST EARLY MON MORNING WILL
ENHANCE THE WINDS. THE GALES OVER THE WRN PORTION OF LAKE SUPERIOR
WILL DIMINISH MON EVENING AS THE PRES GRADIENT WEAKENS AND LOW PRES
SHIFTS E OF THE AREA...RESULTING IN BACKING WINDS. WINDS WILL
DECREASE ACROSS THE LAKE FROM W TO E TUE/TUE NIGHT WITH LIGHT WINDS
MOSTLY UNDER 15KT TO FOLLOW FOR WED/THU AS HIGH PRES BUILDS INTO THE
UPPER LAKES WED AND THEN LINGERS INTO THU. AS THE HIGH PRES SHIFTS
E...WINDS MAY INCREASE A LITTLE FOR THU NIGHT/FRI.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 8 PM EDT /7 PM CDT/ THIS EVENING FOR LSZ162-
263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KC
AVIATION...JLA
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
140 AM EDT MON MAY 11 2015
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 417 PM EDT SUN MAY 10 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW THE WELL-DEFINED MID LEVEL
LOW THAT WAS OVER THE SRN ROCKIES YESTERDAY NOW LIFTING N ACROSS WRN
NEBRASKA/WRN SD. ONE WEAK LEAD SHORTWAVE THAT WAS OVER THE SRN
PLAINS YESTERDAY HAS MOVED NE THRU LWR MI TODAY...SPREADING SHRA AND
A FEW TSRA ACROSS LWR MI. CLOSER TO HOME...WEBCAMS INDICATED SOME
PATCHY -DZ THIS MORNING OVER ERN PARTS OF THE FCST AREA AS LOW
CLOUDS SPREAD BACK INTO MUCH OF UPPER MI. OTHERWISE...NO PCPN HAS
OCCURRED TODAY. CLOUDS HAVE DOMINATED MOST OF THE FCST AREA.
HOWEVER...MUCH OF THE WRN FCST AREA HAS BECOME MOSTLY SUNNY RECENTLY
AS THE LOW CLOUDS HAVE DISSIPATED IN THAT AREA.
TONIGHT AND MON...MID LEVEL LOW MOVING INTO SD WILL GRADUALLY OPEN
UP AS IT DRIFTS INTO MN. ON THIS TRACK...THE STRONGEST DEEP LAYER
FORCING (SHOWN NICELY BY QVECTORS) AND STRONGEST ISENTROPIC ASCENT
WILL FOCUS INTO NRN MN. FARTHER E...A WEAKER EASTWARD EXTENSION OF
DEEP LAYER FORCING COMBINED WITH A RIBBON OF REASONABLY STRONG
ISENTROPIC ASCENT LIFTING NE ACROSS THE AREA SHOULD SUPPORT A PERIOD
OF SHRA...MAINLY LATE TONIGHT THRU MON MORNING. THERE IS VERY LITTLE
TO NO INSTABILITY NOTED ACCOMPANYING THIS BAND OF FORCING/SHRA...SO
THUNDER POTENTIAL IS VERY LIMITED. WILL MAINTAIN A SCHC MENTION ONLY
OVER THE FAR SCNTRL...CLOSER TO SOMEWHAT BETTER ELEVATED INSTABILITY
TO THE S. MID LEVEL DRYING PUSHES INTO THE FCST AREA DURING THE DAY
MON...FOLLOWING THE RIBBON OF ISENTROPIC ASCENT. THIS SHOULD RESULT
IN A TRANSITION TO MAINLY DRY WEATHER OVER MOST OF THE AREA. BETTER
CHC OF LINGERING ISOLD/SCT -SHRA IN THE AFTN WILL BE OVER THE N AND
E. THAT SAID...SEEMS MORE LIKELY THAT WHERE UPSLOPE FLOW PERSISTS...
LINGERING LOW-LEVEL MOISTURE MAY RESULT IN SOME -DZ AND UPSLOPE
FOG...MAINLY ACROSS THE KEWEENAW AND NCNTRL UPPER MI. COMBINATION OF
RAIN AND HIGHER DWPTS SPREADING N OVER LAKE MI WILL LIKELY MEAN FOG
SPREADING UP LAKE MI AND AFFECTING AREAS MAINLY E OF KESC AS WELL.
LATER IN THE AFTN...BROADENING SFC LOW/OCCLUDED FRONT MAY SLIP INTO
THE SRN FCST AREA. GFS/NAM SHOW SOME LOW-LEVEL INSTABILITY (FEW
HUNDRED J/KG) NEAR THIS FEATURE. COULD SPARK ISOLD TSRA LATE...BUT
CONFIDENCE IN THAT OCCURRING IS VERY LOW. AS FOR TEMPS...THERE IS
BIG BUST POTENTIAL WITH MAX TEMPS ON MON. IF THE OCCLUDED FRONT
LIFTS INTO SRN UPPER MI AND CLOUDS BREAK...TEMPS COULD QUICKLY RISE
WELL INTO THE 60S. SOME OF THE BIAS CORRECTED GUIDANCE HAS MAX TEMPS
UP AROUND 70F NEAR THE MI/WI BORDER. FOR NOW...HAVE MAX TEMPS NEAR
60F OVER THE SCNTRL. TO THE N...WHERE FLOW REMAINS UPSLOPE OFF LAKE
SUPERIOR...TEMPS SHOULD NOT RISE HIGHER THAN THE LWR 40S.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 248 PM EDT SUN MAY 10 2015
MUCH OF THIS PERIOD WILL BE COOL...WITH TEMPERATURES ONLY RETURNING
TO NEAR NORMAL FOR DAYTIME HIGHS FOR FRIDAY
FOR MONDAY NIGHT WE WILL START OFF WITH THE 500MB LOW SET UP ACROSS
MN. THE 500MB LOW WILL BECOME AN OPEN WAVE OVERNIGHT AS IT MOVES
OVER LAKE SUPERIOR AND EXITS TO THE NE TUESDAY. AT THE SFC...THE LOW
WILL BE ACROSS THE S HALF OF THE CWA AT 00Z TUESDAY...SHIFTING TO
THE E HALF BY 06Z...AND EXITING NE WITH A TROUGH LINGERING ACROSS
UPPER MI THROUGH MUCH OF THE DAY TUESDAY.
COULD WE HAVE SIGNIFICANT SNOW TUESDAY WITH THE HELP OF FAVORABLE
UPSLOPE WINDS OFF LAKE SUPERIOR BEHIND THE EXITING SFC LOW? WHILE
FCST MODELS ARE INDICATING 0-3IN OF SNOW MAINLY DURING THE DAY
TUESDAY...THERE ARE A FEW NEGATIVES TO ANY SIGNIFICANT SNOW THAT
COULD POSE A THREAT TO COMMERCE. THE NAM AND GFS DO SHOW A NOSE OF
WARMER AIR BETWEEN 750MB AND 800MB RISING ABOVE THE FREEZING LEVEL.
AT THIS POINT IT LOOKS TO BE A SMALL ENOUGH TO ONLY HAVE A SMALL
IMPACT ON SNOW. IT WILL BE NOTHING LIKE THE 20:1 SLR VALUES OF MID
WINTER. RATIOS WILL LIKELY BE ON THE ORDER OF 8:1 AND LOWER. THE MID
MAY SUN IS GIVING NEARLY 15HRS BETWEEN SUNRISE AND SUNSET. CURRENTLY
GOING WITH AN INCH OR LESS...MAINLY OVER THE FAR W HIGHER TERRAIN.
LOOK FOR RIDGING ALOFT ALREADY BY THE END OF THE DAY TUESDAY. THE
INITIAL TROUGH WILL HAVE MOVED TO E ONTARIO/S QUEBEC...WITH A
SECONDARY TROUGH EXTENDING W ACROSS S MANITOBA AND SAKATCHEWAN. AT
THE SFC...WINDS WILL ALREADY BE TURNING MORE OUT OF THE W TUESDAY
NIGHT /MAINLY OVER THE W/...IN RESPONSE TO THE LARGE NEARING AREA OF
HIGH PRESSURE EXTEDING FROM N CANADA THROUGH THE GULF STATES TUESDAY
AFTERNOON THAT WILL PUSH ACROSS THE W HALF OF THE CWA OVERNIGHT.
THE 500MB RIDGE WILL CONTINUE TO BUILD ACROSS THE UPPER GREAT LAKES
THROUGH THURSDAY AS THE CENTRAL CANADIAN TROUGH LINGERS. DRY AND
COOL AIR WILL BE OVERHEAD AS THE SFC HIGH OVER THE GREAT LAKES
THURSDAY MORNING SHIFTS E TOWARDS THE ATLANTIC.
ALTHOUGH WITH DIFFERING TIMING...THERE ARE INDICATIONS THAT A LOW IN
THE SW FLOW WILL BE ABLE TO EJECT UP ACROSS THE N PLAINS ON
THURSDAY. THE 10/12Z ECMWF SOLUTION FOLLOWS SIMILARLY TO THE
CANADIAN...WHILE THE GFS KEEPS THE SYSTEM A WHOLE LOT WEAKER AND
FARTHER TO THE S. CURRENTLY RUNNING WITH SLIGHT CHANCE TO LOW CHANCE
POPS. GIVEN THE UNCERTAINTY WITH THIS 100 PLUS HR FCST...THIS SEEMS
REASONABLE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 138 AM EDT MON MAY 11 2015
CHALLENGING FCST SHAPING UP OVER THE NEXT 24HRS. LOW PRES SYSTEM
MOVING NE THRU THE PLAINS WILL SWING SHRA NE INTO THE UPPER
LAKES...MAINLY LATE IN THE OVERNIGHT HOURS INTO THROUGH MIDDAY
TODAY. ALL SITES SHOULD STAY MVFR REST OF THE NIGHT BUT AS -SHRA
ARRIVE...EXPECT A TREND DOWN TO IFR THIS MORNING AT ALL TERMINALS.
UPSLOPE E-NE FLOW WILL LIKELY RESULT IN LIFR CONDITIONS DEVELOPING AT
KCMX/KSAW BY LATE THIS MORNING. &&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 417 PM EDT SUN MAY 10 2015
TIGHT PRES GRADIENT WILL BE OVER LAKE SUPERIOR TONIGHT THRU MUCH OF
MON AS HIGH PRES REMAINS NEARLY STATIONARY...CENTERED OVER FAR NRN
ONTARIO...AND LOW PRES MOVES FROM NEBRASKA TO FAR NRN WI. AS A
RESULT BRISK NE TO E WINDS OF 15-30KT WILL BE THE RULE ACROSS LAKE
SUPERIOR. THE STRONGEST WINDS (GALE FORCE) WILL BE OVER THE WRN
PORTION OF THE LAKE WHERE COASTAL CONVERGENCE/FUNNELING AND
PERSISTENT PRES FALLS TO THE SW THRU AT LEAST EARLY MON MORNING WILL
ENHANCE THE WINDS. THE GALES OVER THE WRN PORTION OF LAKE SUPERIOR
WILL DIMINISH MON EVENING AS THE PRES GRADIENT WEAKENS AND LOW PRES
SHIFTS E OF THE AREA...RESULTING IN BACKING WINDS. WINDS WILL
DECREASE ACROSS THE LAKE FROM W TO E TUE/TUE NIGHT WITH LIGHT WINDS
MOSTLY UNDER 15KT TO FOLLOW FOR WED/THU AS HIGH PRES BUILDS INTO THE
UPPER LAKES WED AND THEN LINGERS INTO THU. AS THE HIGH PRES SHIFTS
E...WINDS MAY INCREASE A LITTLE FOR THU NIGHT/FRI.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 8 PM EDT /7 PM CDT/ THIS EVENING FOR LSZ162-
263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...JLA
MARINE...ROLFSON
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1117 PM CDT Sun May 10 2015
.UPDATE:
Issued at 1006 PM CDT Sun May 10 2015
While there has been a lull in shower and thunderstorms across the
area over the last few hours, the probability is expected to ramp
back up overnight. A series of disturbances currently present from
eastern TX into eastern OK are forecast to track northeastward
tonight and into the area in advance of the slowly progressive
long wave trof and attendant cold front. Backing mid/upper level
flow and large scale ascent associated with the disturbances along
with increasing low level convergence via the southwesterly LLJ is
expected to promote the northeastward spread of showers and
thunderstorms now occuring across eastern OK and northwest AR.
Recent runs of the RAP, HRRR and new 00z NAM all support this
scenario with the axis of precipitation bi-secting St. Louis at
12z. Instability has waned dramatically in the wake of the earlier
storms and loss of heating and any additional instability increase
overnight should be largely elevated and only weak. This would
suggest the severe weather threat is rather low and in the isolated
category.
Glass
&&
.SHORT TERM: (Through Late Tonight)
Issued at 431 PM CDT Sun May 10 2015
Have heavily leaned towards the afternoon runs of the HRRR for
convective trends heading into the early evening hours. N-S band of
convection is plowing east at 40-45 kts, and will likely be exiting
eastern sections of our CWA shortly after 00z. After an early
evening lull in activity convection should then return to the
CWA...with threat likely a combination of the activity now
increasing along cold front over eastern KS as well as convection
redeveloping just north of Red River.
Believe that this SE OK activity will be the dominate convection
for our area overnight, as current activity will be intensifying
the low level boundary draped across the ARKLATEX, with this dome
of rain-cooled air providing lift to increasing low level jet that
will be transporting very moist air into the region from the
southern Plains. This area will also be in a favorable area of
upper level divergence tied to RRQ of upper level jet.
Once current line of convection exits area, uncertain about
additional severe weather potential overnight. Current activity
as well as latest upstream convection will be putting a big bite
in the instability that will be available, although large scale
shear of 30-50kts still certainly suggests some severe weather
potential. In addition...while some decent rainfalls are likely
over southern sections of the CWA, believe the aforementioned
outflow boundary will keep the heaviest rain threat anchored over
AR...and south of our CWA.
Truett
.LONG TERM: (Monday through Next Sunday)
Issued at 431 PM CDT Sun May 10 2015
Convection should press east and exit the region during the day
on Monday as cold front pushes across the CWA. I`ve held onto much
higher PoPs than guidance for the early part of the morning on the
western edge of the expected precip shield (generally from near
Cuba thru STL to near Carlinville), but then quickly wind them
down to the SE of STL during the late morning and early afternoon
hours. Any severe weather potential will be strongly tied to
morning convection trends, but SWODY2 still looks reasonable that
greatest threat will be in our far southeast counties, where the
AMS will stand at least some chance of destabililzing before fropa
occurs.
As unseasonably strong upper level low spins its way across the
Great Lakes Monday night and Tuesday, it will drag much cooler air
into the area. This should result in a dry Tuesday with temps a
bit below average, as highs will primarily be in the 60s. Ridging
in the wake of the departing low will mean more tranquil weather
by midweek, with temperatures moderating into the 70s.
Another upper level system will mean a return of unsettled weather
heading into the latter half of the week. There is a large
discrepency in the medium range solutions regarding the location and
movement of this feature especially heading into next weekend, but
with all solutions suggesting a frontal boundary remaining over
the area forecast will mention a chance of thunderstorms in most
areas during the Thursday-Sunday time frame.
Truett
&&
.AVIATION: (For the 06z TAFs through 06z Monday Night)
Issued at 1104 PM CDT Sun May 10 2015
Not much change from updated TAFs sent earlier this eve. However,
confidence is low that precip will reach UIN and may just miss to
the E. Precip may miss COU just to the E as well, but confidence
is higher here. For SUS/CPS, area of SHRA with isod TS shud
continue moving newd with timing still around 09z. Timing of
precip leaving these terminals is more uncertain tho.
Otherwise, expect largely VFR conditions with wly winds increasing
with gusts to around 20-25 kts Mon aftn. These gusts shud diminish
during the eve hrs with a clear sky except at UIN with VFR bases.
Specifics for KSTL: SHRA with isod TS expected to arrive around
09z overnight and persist thru mid morning Mon. Winds will become
wly with gusts to around 25 kts and shud be slow to dissipate Mon
eve. VFR conditions largely expected outside of heavier RA.
Tilly
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS GREAT FALLS MT
1120 PM MDT SUN MAY 10 2015
AVIATION SECTION UPDATED
.DISCUSSION...
UPDATE FORTHCOMING. AN UPPER TROF ALONG THE CANADIAN BORDER WILL AID
IN THE DEVELOPMENT OF ISOLATED SHOWERS THIS EVENING. RADAR RETURNS
SHOWING THESE SHOWERS DEVELOPING AT THIS TIME. SPC MESOSCALE
ANALYSIS INDICATES POCKETS OF CAPE OF A FEW HUNDRED J/KG WITH
HIGHER VALUES JUST ACROSS THE INTERNATIONAL BOUNDARY. LI VALUES ARE
SLIGHTLY BELOW ZERO. HRRR ANALYSIS KEEPS CONVECTIVE ACTIVITY ONGOING
THROUGH 10Z BEFORE IT DECREASES. AS A RESULT, HAVE PAINTED LOW POPS
ACROSS A BROADER AREA OVERNIGHT. ACTUAL QPF AMOUNTS STILL EXPECTED
TO BE VERY LOW. REMAINDER OF AREA WILL BE DRY. TEMPERATURES LOOK
GOOD.
&&
.AVIATION...
UPDATED 0520Z. VFR CONDITIONS EXPECTED THROUGH THE OVERNIGHT PERIOD
AND MONDAY. WEAK UPPER DISTURBANCE EXTENDING FROM KGPI TO KGGW IS
SETTING OFF SOME ISOLATED -SHRA VCNTY KCTB/KHVR BUT CEILINGS SHOULD
REMAIN AT/ABOVE 7000 FT. PRECIPITATION SHOULD TAPER OFF BY 09-10Z.
REST OF LOCAL TAF SITES WILL SEE CLEAR SKIES OR SCT HIGH CLOUDS
TONIGHT. LIGHT SURFACE WINDS ARE FORECAST ACROSS THE REGION.
WARANAUSKAS
&&
.PREV DISCUSSION...ISSUED 259 PM MDT SUN MAY 10 2015
SUNDAY THROUGH TUESDAY...COOL CONDITIONS WILL SLOWLY YIELD TO
WARMING TEMPERATURES AS SOME WEAK SHORTWAVES MOVE NEAR THE AREA
AND WILL PRODUCE LIMITED INSTABILITY ACROSS THE REGION. MOST OF
THE INSTABILITY WILL BE SEEN AS INCREASED DEVELOPMENT IN
AFTERNOON CLOUDS WITH SOME SHOWERS OVER THE HIGHER TERRAIN. SOME
ISOLATED SHOWERS WILL BE POSSIBLE ALONG THE ROCKY MOUNTAIN FRONT
AND CANADIAN BORDER SUNDAY EVENING AS A SHORTWAVE MOVES ACROSS
CANADA. ANOTHER SYSTEM WILL MOVE SOUTH OF MONTANA ON MONDAY
AFTERNOON AND COULD PRODUCE SHOWERS OFF THE HIGHER TERRAIN IN
SOUTHWEST MONTANA. OTHERWISE CONDITIONS SHOULD BE RELATIVELY QUIET
AS THE RIDGE OVER THE SOUTHERN UNITED STATE CONTINUES TO INFLUENCE
THE WEATHER PATTERN MORE AND MORE FOR MONTANA. SUK
TUESDAY NIGHT THROUGH SUNDAY...HIGH PRESSURE WILL BE SLIDING EAST
TUESDAY NIGHT AS A BROAD AREA OF LOW PRESSURE AND MOIST SOUTHWEST
FLOW MOVES ACROSS THE PACIFIC NORTHWEST. MOISTURE AHEAD OF THIS
SYSTEM WILL INCREASE THE CHANCE OF SHOWERS ACROSS THE NORTHERN AND
EASTERN PORTIONS OF THE REGION. THE LOW PRESSURE SYSTEM WILL
CONTINUE TO MOVE TOWARDS SOUTHWEST MONTANA AND THE AIRMASS WILL
BECOME A BIT UNSTABLE WEDNESDAY WITH MAINLY THE SOUTHWEST AND
CENTRAL ZONES SEEING SOME THUNDERSTORMS. THE AREA WILL REMAIN RATHER
MOIST THROUGH WEDNESDAY NIGHT BUT WEAK HIGH PRESSURE WILL RETURN
THURSDAY ALONG WITH SOME DRIER CONDITIONS, HOWEVER, THE AIRMASS WILL
REMAIN UNSETTLED AND AFTERNOON SHOWERS WILL BE POSSIBLE...AND
AFTERNOON THUNDERSTORMS ACROSS SOUTHWEST MONTANA. A LOW PRESSURE
SYSTEM WILL MOVE OVER NORTHERN CALIFORNIA FRIDAY AND MOVE INTO
NEVADA DURING THE NIGHT. THIS WILL BRING MOISTURE INTO THE SOUTHWEST
ZONES WHICH WILL THEN SPREAD NORTHEASTWARD. HEIGHTS OVER THE REGION
WILL BEGIN TO DROP AHEAD OF THIS SYSTEM AND SOME INSTABILITY AND
THUNDERSTORM DEVELOPMENT WILL COME WITH THE AFTERNOON AND EVENING
PRECIPITATION. THE LOW PRESSURE CENTER WILL MOVE TOWARDS EXTREME
SOUTHERN SOUTHWEST MONTANA BY THE WEEKEND. THE ASSOCIATED LOW
PRESSURE SYSTEM WILL BRING WRAP AROUND CIRCULATION AND MOISTURE
ACROSS THIS AREA FOR POTENTIALLY HEAVY PRECIPITATION ACROSS PORTIONS
OF SOUTHWEST MONTANA. ZELZER
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 33 63 37 58 / 0 10 20 20
CTB 33 56 32 56 / 10 20 10 20
HLN 35 65 40 63 / 0 10 30 30
BZN 27 62 38 63 / 0 10 20 30
WEY 22 57 30 62 / 0 10 20 40
DLN 32 64 40 64 / 0 20 20 30
HVR 32 65 34 63 / 10 20 10 20
LWT 32 62 37 60 / 10 10 20 30
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
WEATHER.GOV/GREATFALLS
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
200 AM EDT MON MAY 11 2015
.SYNOPSIS...
ABOVE NORMAL TEMPERATURES WILL CONTINUE FOR THE NEXT COUPLE OF
DAYS ACROSS CENTRAL NEW YORK AND NORTHEAST PENNSYLVANIA.
ADDITIONAL SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE TOMORROW. A
STORM SYSTEM WILL MOVE THROUGH THE AREA WEDNESDAY BRINGING THE
CHANCE FOR ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS ALONG WITH
AND COOLER AIR.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
845 PM UPDATE...
FRONT CONTINUES TO HANG ACROSS NORTHERN AND WESTERN NY, WITH
SHOWERS AND EMBEDDED THUNDER SLIDING NORTHEASTWARD FROM THE
CENTRAL SO TIER TO THE WESTERN MOHAWK VALLEY. NAM12 TRIES TO BREAK
THIS ACTIVITY UP OVER THE NEXT 1-2 HOURS. HOWEVER THE HRRR KEEPS
THE ACTIVITY GOING THROUGH 8Z OR SO, AND AS OF NOW THE HRRR PROG
LOOKS TO BE HANDLING THE SITUATION BETTER.
INCREASED POPS FOR THE OVERNIGHT ALONG THE PRECIP STREAM.
245 PM EDT UPDATE... THE BACKDOOR FRONT DID MAKE IT INTO CENTRAL
NY TODAY AND IS NOW STATIONARY ALONG CENTRAL NY. BELIEVE THIS IS
AS FAR SOUTH AS IT WILL MOVE THIS AFTERNOON AS 2HR SFC PRESSURE
CHANGES ARE VERY WEAK AND SYNOPTICALLY THERE ISN`T MUCH IN THE WAY
OF FORCING TO PUSH IT FURTHER SOUTH. CONVECTION IS CURRENTLY ON-
GOING ALONG THIS BOUNDARY AND IT APPEARS THAT THEY ARE LOOSELY
DEVELOPED THUNDERSTORMS... IN THE SENSE OF 0-6 KM BULK SHEAR IS
NOT IMPRESSIVE AND THESE OUT DOWNDRAFT DOMINANT. THESE SHOWERS MAY
PRODUCE SOME GUSTY WINDS AND AT BEST SMALL NON-SEVERE SIZE HAIL
ALONG WITH BRIEF HEAVY RAINFALL. FREQUENT LIGHTNING MAY BE
POSSIBLE WITH THESE SHOWERS.
EXPECT COVERAGE OF THE SHOWERS TO INCREASE THIS AFTERNOON AS
INSTABILITY WILL INCREASE. THESE STORMS WILL MOVE TO THE NE
AROUND 20-25 MPH. THE INTENSITY OF THESE STORMS WILL WEAKEN AFTER
SUNSET AS SHOWERS ALONG THE FRONT ARE DIURNALLY DRIVEN. SOME
ISOLATED SHOWERS MAY LINGER AS WEAK INSTABILITY WILL STILL LINGER
THRU THE OVERNIGHT. THIS FRONT WILL LIFT NORTHWARD TONIGHT AND
TRANSITION INTO A PSEUDO-WARM FRONT.
TEMPS THIS AFTERNOON WILL AGAIN BE WELL ABOVE THE SEASONAL NORM.
TEMPS WILL RISE INTO THE 80S... AND MAYBE PEAK INTO THE 90S. TEMPS
ARE EXPECTED TO FALL INTO THE LOWER 60S BY SUNRISE ON MONDAY.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH WEDNESDAY/...
330 PM EDT UPDATE...
MONDAY AFTERNOON WILL BECOME UNSTABLE AGAIN AS WE REMAIN WITHIN
THE WARM SECTOR AND PLENTY OF MOISTURE WILL BE PRESENT. TEMPS
WILL REACH THE LOW 80S RESULTING IN ANOTHER UNUSUALLY WARM DAY. A
POTENT UPPR LVL TROUGH WILL MOVE INTO THE GREAT LAKES REGION
MONDAY AND PUSH A SFC LOW PRESSURE SYSTEM ACROSS THE MIDWEST.
THIS SFC LOW WILL EVENTUALLY DRAG A COLD FRONT OVER THE REGION BY
MID WEEK.
SCATTERED SHOWERS ARE EXPECTED TO DEVELOP QUICKLY LATE MONDAY MORNING
ACROSS MUCH OF THE AREA. THERE MAY BE A SLIGHT LULL IN ACTIVITY
MONDAY EVENING BEFORE ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS
MOVES INTO THE CWA AHEAD OF AN APPROACHING COLD FRONT.THE COLD
FRONT IS EXPECTED TO MOVE THROUGH THE AREA TUESDAY MORNING. WINDS
WILL BE BREEZY BEHIND THE FROPA. SHOWERS AND THUNDERSTORMS MAY
LINGER THRU WED AFTERNOON. ENVIRONMENTAL CONDITIONS DO NOT LOOK
FAVORABLE TO SEVERE WITH ALONG THE COLD FRONT.
THE FRONT WILL BRING A COLDER AIRMASS OVER THE REGION. THIS WILL
RESULT IN TEMPS SLOWLY FALLING DURING THE AFTERNOON. TEMPS WILL
FALL INTO THE LOW TO MID 40S BY WED MORNING. DUE TO THE MUCH
COOLER AIRMASS TEMPS ARE ONLY EXPECTED TO RISE INTO THE 50S ACROSS
MUCH OF THE AREA WED AFTERNOON.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
430 PM UPDATE...
FAIRLY QUIET OVERALL WITH HIGH PRESSURE BUILDING IN WEDNESDAY
NIGHT AND IN CHARGE TO FRIDAY. PATCHY FROST A POSSIBILITY IN OUR
MORE PRONE COLD SPOTS WEDNESDAY NIGHT IF WINDS DECOUPLE FAST
ENOUGH FOR A PERIOD OF GOOD RADIATIONAL COOLING. TO A LESSER
DEGREE...THURSDAY NIGHT AS WELL IF HIGH THIN CLOUDS DO NOT SPREAD
IN ON TIME AHEAD OF NEXT WAVE. THIS WAVE TRANSLATES THROUGH
ROUGHLY ZONAL FLOW...WHICH BRING A BATCH OF SHOWERS LATE FRIDAY
NIGHT INTO SATURDAY /BETTER FOCUS IS TO OUR SOUTH/. AFTER COOL
TEMPERATURES THROUGH LATE WEEK...TEMPERATURES WILL TREND BACK TO
NORMAL OR EVEN SLIGHTLY ABOVE BY LATE IN THE WEEKEND.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
A TRICKY TAF FORECAST WITH A FRONTAL BOUNDARY ACROSS THE NY
TERMINALS WHICH WILL COMPLICATE THE CLOUD FORECAST AND THUS THE
POTENTIAL FOR FOG.
VFR EXPECTED AT KAVP AND KBGM AS THESE TWO SITES REMAINED DRY
SUNDAY AND THUS HAVE THE LOWEST POTENTIAL FOR FOG.
IFR VSBYS LIKELY AT KELM AND KITH. BOTH TERMINALS SAW RAIN SUNDAY
AND ARE EXPECTED TO BE CLEAR FOR AT LEAST PART OF THE NIGHT. THE
FOG MAY BE VARIABLE IN NATURE DUE TO SOME STRONGER WINDS OFF THE
DECK AND VARYING PERIODS OF CLEAR SKY. USED A TEMPO GROUP TO SHOW
THIS VARIABLE NATURE BEFORE LOCKING IN THE FOG AFTER 09Z/10Z.
AT KSYR AND KRME MOST OF THE NIGHT WILL BE CLOUDY WITH SHOWERS
AROUND. WITH THAT SAID ANY AMOUNT OF CLEAR SKY, EVEN SHORT IN
DURATION, WILL LIKELY LEAD TO FOG DUE TO OUR WET GROUND FROM
EARLIER RAINS. FEEL BEST SHOT FOR IFR VSBYS WILL BE AT KRME AS
THEY ARE ALREADY HAD PERIODS OF FOG EARLIER IN THE NIGHT.
WINDS LIGHT AND VARIABLE THROUGH DAYBREAK THEN BECOMING SOUTHWEST
AROUND 10 KTS.
.OUTLOOK...
MON NGT INTO TUE...RESTRICTIONS ARE POSSIBLE IN SHWRS/TSTMS.
WED-FRI...MAINLY VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...KAH
NEAR TERM...DJP/KAH
SHORT TERM...KAH
LONG TERM...MDP
AVIATION...HEDEN
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
340 PM EDT MON MAY 11 2015
.SYNOPSIS...
AFTERNOON SHOWERS AND THUNDERSTORMS TODAY AND AGAIN ON TUESDAY
WILL PRECEDE A COLD FRONT FRONT TUESDAY NIGHT. LESS HUMID AIR
ARRIVES ON WEDNESDAY AND SHOULD LAST INTO THURSDAY AS HIGH
PRESSURE MOVES OVERHEAD. THE LATTER PART OF THE WEEK AND WEEKEND
WILL FEATURE A GRADUAL INCREASE IN HUMIDITY AND THUNDERSTORM
CHANCES AS THE HIGH MOVES OFF THE COAST.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
AS OF 330 PM MONDAY...VERY INTERESTING WEATHER DAY FOR MESOSCALE
FEATURES ONGOING ACROSS THE CWA. FIRST...CONVECTION HAS BLOSSOMED
ACROSS THE SOUTHERN AND EASTERN TIER AS EXPECTED...AND DEPICTED WELL
BY THE HRRR. A WEAK SURFACE TROUGH LIFTING NE THROUGH THE CWA...AS
WELL AS THE STRONG SEA BREEZE BOUNDARY PUSHING NW...ARE SERVING AS
FOCI FOR CONVECTION. THE ENVIRONMENT IS QUITE UNSTABLE...WITH UPR
60S AND LOW 70S DEWPOINTS LEFT IN THE WAKE OF TROPICAL STORM ANA
PROVIDING FUEL FOR 2000-3000 J/KG OF SBCAPE. LOW-LEVEL LAPSE RATES
ARE QUITE STEEP...BUT THEY WEAKEN CONSIDERABLY ABOVE 600 MB. THIS IS
IMPORTANT BECAUSE THE -10 TO -30 C (HAIL GROWTH ZONE) IS ABOVE THAT
LAYER. THIS SUGGESTS THAT...WHILE CONVECTION WILL REMAIN SCATTERED
TO NUMEROUS THIS AFTN...SEVERE WILL BE UNLIKELY DUE TO MUCH WEAKER
UPDRAFTS IN THE HAIL ZONE AND LOTS OF MELTING OF HAIL ON THE WAY
DOWN. STILL...SPC HAS INCLUDED OUR AREA IN AN MCD (5%) FOR ISOLATED
SEVERE THANKS TO MERGING BOUNDARIES POSSIBLY PRODUCING A LARGE HAIL
STONE OR MARGINAL WIND GUST.
WILL CONTINUE CHC/LKLY POP THROUGH NIGHTFALL BUT A RAPID DECREASE IN
COVERAGE IS EXPECTED WITH LOSS OF HEATING. A RESIDUAL LAYER OF
ELEVATED INSTABILITY IS PROGGED IN SOUNDINGS TO PERSIST WELL AFTER
DARK...SO ALTHOUGH THE HRRR SHOWS NO PRECIP AFTER MIDNIGHT...HAVE
OPTED TO KEEP SCHC/ISO SHOWERS THROUGH THE OVERNIGHT.
THE OTHER INTERESTING FEATURE TONIGHT HAS BEEN SEA FOG WHICH
DEVELOPED SOMEWHAT SURPRISINGLY THIS AFTN AND ADVECTED INTO THE
GRAND STRAND AND BRUNSWICK COUNTY. WE ARE BEYOND THE
CLIMATOLOGICALLY FAVORED SEASON FOR SEA FOG...AND THE LOCAL DECISION
TREE SUGGESTS VSBYS SHOULD BE UNRESTRICTED. YET...SEA FOG DID
DEVELOP AND BOTH THE HORRY AND BRUNSWICK COUNTY COASTS ARE "SOCKED
IN` AS OF THIS WRITING. IT IS BELIEVED THAT UPWELLING FROM LONG
DURATION OFFSHORE WINDS ON THE BACKSIDE OF RECENTLY-DEPARTED
TROPICAL STORM ANA COOLED THE SHELF WATERS ENOUGH TO PRODUCE THE
REQUIRED AIR-TO-OCEAN TEMP GRADIENT, THIS COMBINED WITH THE SW FLOW
TO CREATE LONG ENOUGH PARCEL RESIDENCE TIMES FOR SATURATION AND SEA
FOG. CERTAINLY AN INTERESTING SITUATION AND ONE FROM WHICH WE CAN
LEARN! STILL EXPECT VISIBILITY TO IMPROVE IN THE NEXT HOUR OR TWO AS
CONDITIONS ARE FAR FROM IDEAL FOR PERSISTENT SEA FOG.
MINS TONIGHT WILL BE HELD ABOVE CLIMO THANKS TO CONTINUED SW RETURN
FLOW...AND LOWS WILL DROP TO A DEGREE OR TWO EITHER SIDE OF
70...WARMEST AT THE COAST. GUIDANCE IS SUGGESTING STRATUS
DEVELOPMENT TONIGHT...AND IN THIS MOIST COLUMN IT IS DEFINITELY
PLAUSIBLE. HAVE SHOWN AN INCREASE IN CLOUD COVER AFTER
MIDNIGHT...WHICH WILL ALSO HELP TO KEEP MINS ELEVATED.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
AS OF 330 PM MONDAY...WEAK COLD FRONT WILL PUSH ACROSS THE AREA
LATE TUE NIGHT. AHEAD OF THE FRONT THE ENVIRONMENT APPEARS RIP FOR
DEVELOPMENT OF AFTERNOON CONVECTION. DEEP MOISTURE IS PRESENT WITH
FORECAST SOUNDINGS CARRYING PRECIPITABLE WATER VALUES OF 1.5 TO
1.6 INCH...WHICH IS WITHIN THE HIGHEST 10% FOR EARLY MAY.
SOUNDINGS CONTINUE TO ADVERTISE ML CAPE IN THE 2K TO 2.5K J/KG
RANGE WEST OF THE SEA BREEZE...WHICH WEST-SOUTHWEST FLOW SHOULD
KEEP CLOSER TO THE COAST. THE AFOREMENTIONED SEA BREEZE AND
PREFRONTAL TROUGH ARE LIKELY TO INITIATE AFTERNOON CONVECTION WITH
OUTFLOW DEVELOPING ADDITIONAL STORMS. MUCH OF THE AREA REMAINS IN
THE SPC DAY 2 OUTLOOK MARGINAL AREA AND FORECAST SOUNDINGS DO
SUGGEST SOME POTENTIAL FOR ISOLATED STRONG TO SEVERE STORMS.
HOWEVER...ORGANIZED WIDESPREAD STRONG/SEVERE ACTIVITY IS NOT
LIKELY. SHEAR IS NOT PARTICULARLY STRONG BUT LIFTED INDEX VALUES
ARE -5C TO -6C AND FAIRLY STRONG UPDRAFTS SHOULD BE POSSIBLE.
FREEZING LEVEL AROUND 13K FT LIKELY RULES OUT SIZABLE HAIL SO THE
MAIN THREAT WOULD BE ISOLATED DAMAGING WIND GUSTS.
COLD FRONT PUSHES ACROSS THE AREA TUE NIGHT WITH MUCH DRIER AIR MASS
BUILDING IN BEHIND IT. PRECIPITABLE WATER VALUES DROP OVER AN INCH
TUE INTO WED. DEEP NORTHWEST FLOW/MID LEVEL SUBSIDENCE WILL KEEP
SKIES CLEAR WED AFTERNOON. THE ONLY CAVEAT WILL BE ACROSS THE
COASTAL SC COUNTIES. THERE IS A WEAK SHORTWAVE CROSSING SC...WHICH
DOES HELP PUSH THE FRONT THROUGH...BUT THIS SHORTWAVE COULD TAKE A
BIT LONGER TO PUSH OFF THE SC COAST. IF THAT HAPPENS CLOUDS COULD
LINGER ACROSS SOUTHERN PORTIONS OF THE FORECAST AREA. AT THIS POINT
DO NOT THINK PRECIP WILL LINGER INTO WED BUT WILL CARRY A NON-ZERO
POP FOR THE MORNING HOURS.
TEMPS WELL ABOVE CLIMO TUE WILL COOL OFF QUITE A BIT WED BUT HIGHS
STILL END UP RIGHT AROUND CLIMO...SHOWING JUST HOW WARM TUE IS GOING
TO BE. LOWS ABOVE CLIMO TUE NIGHT WILL BE NEAR TO SLIGHTLY BELOW
CLIMO WED NIGHT.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 3 AM SUNDAY... MID LEVEL RIDGE OVERHEAD THURSDAY WHILE SURFACE
HIGH REMAINS TO OUR NORTH. LIKE WEDNESDAY WE EXPECT ANOTHER SUNNY
AND SEASONABLE DAY WITH FAIRLY LOW HUMIDITY. THIS WILL CHANGE
THURSDAY NIGHT INTO FRIDAY AS BOTH MOVE EASTWARD. THE WARMING WILL
BE RATHER GENTLE BUT THE HUMIDITY CREEPING UP MORE NOTICEABLE. THE
WEEKEND SHOULD THUS BRING FAIRLY SEASONABLE WARMTH AND HUMIDITY BUT
ALSO AT LEAST A SCATTERING OF MAINLY DIURNAL CONVECTION.
&&
.AVIATION /20Z MONDAY THROUGH SATURDAY/...
AS OF 18Z...THE HRRR MODEL SEEMS TO THINK WE WILL HAVE QUITE A BIT
OF CONVECTION THIS AFTERNOON...PARTICULARLY IN SOUTH CAROLINA. THERE
IS SOME SUBSIDENCE AROUND THE REMNANTS OF ANA...BUT THAT WILL BE
WANING THROUGH THE AFTERNOON HOURS SO SOME CONVECTION IS
EXPECTED...BUT WITH COVERAGE MAINLY CONFINED TO THE SEA BREEZE
BOUNDARY AND PLACES THAT RECEIVED FULL SUN TODAY. TONIGHT...MODELS
DO NOT SEEM TO THINK WE WILL SEE ANY FOG...BUT WITH ALL THE RAIN
THAT FELL ALONG THE COAST...EXPECT POSSIBLY SOME MVFR
FOG...ESPECIALLY HORRY AND BRUNSWICK COUNTIES. HOWEVER...RESIDUAL
WINDS AND LOW-LEVEL MOISTURE MAY DRIVE A STRATUS LAYER INSTEAD OF
FOG...AND HAVE SHOWN IFR IN ALL TAFS FOR LOW OVC. TUESDAY...CHANCES
FOR CONVECTION WILL INCREASE NEAR THE END OF THE FORECAST PERIOD
WITH A COLD FRONT.
EXTENDED OUTLOOK...SCATTERED SHOWERS POSSIBLE TUE EVENING AND AGAIN
ON FRIDAY. OTHERWISE EXPECT VFR..
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 330 PM MONDAY...ALL HEADLINES HAVE DROPPED FROM EARLIER TODAY
AS CONDITIONS HAVE IMPROVED ACROSS THE COASTAL WATERS. RESIDUAL
LARGE WAVES AND GUSTY WINDS FROM TROPICAL STORM ANA HAVE SHIFTED
WELL NE OF THE WATERS...WHICH ARE NOW UNDER THE INFLUENCE OF RETURN
SW FLOW. THIS WILL CONTINUE THROUGH TONIGHT...WITH FAIRLY STEADY 10-
15 KT SW WINDS...ALTHOUGH A FEW GUSTS TO 20 KTS WILL BE POSSIBLE
THROUGH THIS AFTN...ESPECIALLY ALONG THE SEA BREEZE IN THE NEAR
SHORE WATERS. SEAS WILL BE 2-4 FT...WITH A 6-7 SECOND PERIOD WAVE
PREDOMINANT.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 330 PM MONDAY...SOUTHWEST FLOW AHEAD OF A COLD FRONT WILL
INCREASE AS GRADIENT AHEAD OF THE FRONT TIGHTENS. SPEEDS PEAK AROUND
20 KT IN TUE AFTERNOON AND EVENING WITH SEAS RUNNING 3 TO 4 FT.
WINDS VEER TO WESTERLY LATE TUE NIGHT AS THE FRONT CROSSES THE
WATERS. WEAK HIGH PRESSURE BUILDING IN BEHIND THE FRONT LIMITS THE
STRENGTH OF THE GRADIENT AND DEVELOPING OFFSHORE FLOW WILL BE UNDER
15 KT EARLY WED. WINDS WILL QUICKLY VEER TO NORTHEAST FOR WED BUT
GRADIENT REMAINS ILL DEFINED AND SPEEDS STAY 15 KT WITH SEAS
RUNNING 2 TO 3 FT THROUGH THE END OF THE PERIOD.
LONG TERM /THURSDAY THROUGH FRIDAY/...
AS OF 3 AM SUNDAY... THE HIGH LOCATED TO OUR NORTH DURING THE
SHORT TERM PROGRESSES EAST DURING THE LONG TERM. WINDS VEER FROM N
TO E EARLY IN THE PERIOD AND SHALL MORE OR LESS REMAIN SAVE FOR
PERHAPS A SLIGHT ADDITIONAL VEER TO SE BY FRIDAY. THERE WILL BE NO
APPRECIABLE SWELL ENERGY TO SPEAK OF SO THE FAIRLY MINOR WIND
WAVES WILL BE THE DOMINANT SEA STATE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...JDW
SHORT TERM...III
LONG TERM...MBB
AVIATION...JDW/DL
AREA FORECAST DISCUSSION
NWS RALEIGH NC
315 PM EDT MON MAY 11 2015
.SYNOPSIS...THE REMNANTS OF TROPICAL CYCLONE ANA WILL TRACK
NORTHEAST INTO VIRGINIA THIS AFTERNOON. A COLD FRONT WILL MOVE
THROUGH THE AREA TUESDAY AFTERNOON AND EVENING. COOL HIGH PRESSURE
WILL BUILD INTO THE AREA THROUGH MID-WEEK.
&&
.NEAR TERM /TONIGHT/...
AS OF 315 PM MONDAY...
WEAKENING REMAINS OF TC ANA WILL CONTINUE TO MOVE NORTHEASTWARD INTO
SOUTHEAST VA THIS AFTERNOON AND EVENING WITH AN EXPECTED INCREASE IN
ACCELERATION AS SW FLOW ALOFT STRENGTHENS IN ADVANCE OF A MID/UPPER
LEVEL TROUGH MOVING NORTHEASTWARD INTO THE MID/UPPER VALLEY.
IN THE WAKE OF TC ANA EXITING THE AREA...MODERATE DESTABILIZATION OF
2000-2500 J/KG PER SPC MESOANALYSIS HAS DEVELOPED IN RESPONSE TO
STEEP LOW-LEVEL LAPSE RATES ATOP A SEASONABLY MOIST BOUNDARY LAYER
FEATURING BL DEWPOINTS IN THE UPPER 60S TO LOWER 70S. FORCING FOR
ASCENT THIS AFTERNOON AND EVENING LOOKS TO BE DRIVEN BY TWO SEPARATE
WEAK FEATURES...1)ALONG SHALLOW CONVERGENCE ATTENDANT TO A
DEVELOPING SURFACE TROUGH IN THE LEE OF THE MOUNTAINS AND 2) A WEAK
UPPER LEVEL DISTURBANCE OVER SW NC/SC.
INITIALLY...EXPECT CONVECTION TO BE CONFINED TO THE WESTERN PIEDMONT
AND SANDHILLS/SOUTHERN COASTAL PLAIN WHERE THE SUPPRESSIVE INFLUENCE
OF SUBSIDENCE ON THE WESTERN PERIPHERY OF TC ANA`S REMNANTS WILL NO
LESS. GIVEN WEAK FORCING...EXPECT CONVECTION TO BE LARGELY DIURNAL
IN NATURE...AND THUS EXPECT MUCH OF THE ACTIVITY TO DROP OFF QUICKLY
AFTER SUNSET. HOWEVER...THE LATEST HRRR SUGGEST INITIAL STORMS OUT
WEST COULD PERSIST THROUGH MIDNIGHT AS THEY WORK SLOWLY EASTWARD
INTO THE COASTAL PLAIN. HAVE EXTENDED SMALL CHANCE POPS THROUGH 05-
06Z. WRT TO SEVERE WX...WEAK DEEP LAYER SHEAR OF 10-15 KTS WILL
PRECLUDE A MORE ORGANIZED THREAT. HOWEVER...GIVEN MODERATE
INSTABILITY AND DCAPE ~1000J/KG CANNOT RULE OUT AN ISOLATED SEVERE
STORM CAPABLE OF PRODUCING LOCALIZED WIND DAMAGE....ESPECIALLY IN
THE WEST IN PROXIMITY TO DRIER AIR.
UNDER PARTLY TO MOSTLY CLOUDY MID AND HIGH CLOUDS...EXPECT MILD
OVERNIGHT LOWS IN THE UPPER 60S TO NEAR 70.
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 315 PM MONDAY...
MID AND UPPER LEVEL FLOW REALLY FLATTENS OUT...BECOMING WESTERLY ON
TUESDAY AS THE WELL REMOVED UPPER TROUGH TRAVERSE THE UPPER GREAT
LAKES/NEW ENGLAND. ATTENDANT SURFACE LOW TRACKING THROUGH SE CANADA
WILL DRAG A COLD FRONT THROUGH THE AREA BETWEEN 18Z TUESDAY IN THE
WEST TO 00 TO 03Z IN THE EAST. GUIDANCE SUGGESTS BL DEWPOINTS WILL
BE APT TO MIX OUT A BIT...ESPECIALLY OVER THE WESTERN PIEDMONT
TUESDAY AFTERNOON. THE WESTERLY COMPONENT ALOFT AND LACK OF SUPPORT
ALOFT WILL TEND TO SUPPRESS CONVECTION ACROSS A LARGE CHUNK OF THE
FORECAST WITH CONVECTION MOST APT TO FIRE ACROSS EASTERN PIEDMONT
AND COASTAL PLAIN(I-95 CORRIDOR)...WHERE LINGERING LOW-LEVEL
MOISTURE AND STRONG INSOLATION COULD SUPPORT MODERATE TO STRONG
DESTABILIZATION OF 2000-3000 J/KG OF SBCAPE. WRT TO SEVERE
POTENTIAL...DEEP LAYER SHEAR MAY BE MARGINALLY BETTER THAN TODAY...
BUT NOT BY MUCH...PARTICULARLY IN THE EAST. THUS A FEW STRONG TO
SEVERE THUNDERSTORMS CAPABLE OF PRODUCING LOCALIZED WIND DAMAGE MAY
DEVELOP ACROSS THE EASTERN PIEDMONT/COASTAL PLAIN AREAS.
LOW-LEVEL THICKNESSES WILL BE MORE REPRESENTATIVE OF MID TO LATE
JUNE AS OPPOSED TO EARLY MAY. EXPECT HIGHS IN THE UPPER 80S TO LOWER
90S...WHICH WOULD BE THE FIRST TIME WE REACHED 90 DEGREES AT KRDU
AND KFAY.
SKIES SHOULD CLEAR OUT TUESDAY EVENING/NIGHT WITH CAA DRIVING
OVERNIGHT LOWS. LOWS RANGING FROM MID 50S NW TO LOWER 60S SE.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
AS OF 300 PM MONDAY...
SURFACE HIGH PRESSURE WILL BUILD INTO THE REGION FROM THE GREAT
LAKES WEDNESDAY THROUGH THURSDAY...BEFORE SHIFTING OFFSHORE THURSDAY
NIGHT INTO FRIDAY. AT THE SAME TIME...MID LEVEL RIDGING WILL BUILD
OVER THE AREA FROM THE EAST. MUCH COOLER AND DRIER AIR WILL FILTER
INTO THE REGION...RESULTING IN A PERIOD OF DRY WEATHER AND NEAR TO
SLIGHTLY BELOW NORMAL TEMPS.
AS THE SURFACE HIGH CONTINUES TO SHIFT OFFSHORE ON FRIDAY...MOISTURE
WILL BEGIN TO RECOVER ON THE BACK SIDE OF THE HIGH. HOWEVER...THE
MID LEVEL RIDGING WILL STICK AROUND FOR A WHILE LONGER WHICH MAY
PREVENT WIDESPREAD CONVECTION. AS OF NOW...IT APPEARS THE BEST
CHANCE OF A SHOWER OR STORM WILL BE ACROSS THE WESTERN PIEDMONT ON
FRIDAY AND SATURDAY...WITH CHANCES SPREADING EAST (AND INCREASING)
SUNDAY INTO MONDAY AS MOISTURE AND INSTABILITY INCREASES EVEN MORE.
TEMPS WILL GRADUALLY WARM EACH DAY...WITH HIGHS GENERALLY IN THE MID
80S AND OVERNIGHT LOWS IN THE MID 60S BY EARLY NEXT WEEK.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 130 PM MONDAY...
24-HR TAF PERIOD: AS ANA`S REMNANTS CONTINUES TO LIFT NORTHEAST...
AWAY FROM THE AREA...OUTSIDE OF ISOLATED TO WIDELY SCATTERED
CONVECTION...EXPECT PREDOMINATELY VFR CONDITIONS THIS AFTERNOON AND
EVENING. A STEADY 5 TO 10KT SWLY BREEZE OVERNIGHT IN ADVANCE OF A
COLD FRONT APPROACHING FROM THE WEST SHOULD PRECLUDE ANY FOG
DEVELOPMENT OVERNIGHT/EARLY TUESDAY MORNING. ADDITIONALLY...GIVEN
MOIST LOW-LEVELS COULD SEE SOME SUB-VFR STRATUS EARLY TUESDAY
MORNING...ESPECIALLY AT KFAY WHERE BETTER LOW-LEVEL MOISTURE IS
EXPECTED. SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO
ACCOMPANY A COLD FRONTAL PASSAGE THROUGH THE AREA
TUESDAY AFTERNOON...ESPECIALLY ALONG AND EAST OF RDU.
LOOKING AHEAD: EXPECT DRY VFR CONDITIONS TUESDAY NIGHT THROUGH
FRIDAY ASSOCIATED WITH COOL HIGH PRESSURE BUILDING OVER THE AREA.
THE HIGH WILL PUSH OFFSHORE ON FRIDAY. SOUTHERLY RETURN FLOW ON THE
WESTERN PERIPHERY OF THE HIGH WILL BRING AN INCREASE LIKELIHOOD OF
SUB-VFR CONDITIONS IN MORNING FOG AND/OR STRATUS ALONG WITH A
CHANCE OF MAINLY AFTERNOON SHOWERS AND STORMS LATE FRIDAY NIGHT
AND INTO THE WEEKEND.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT/CBL
NEAR TERM...CBL
SHORT TERM...CBL
LONG TERM...KRD
AVIATION...CBL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
122 PM EDT MON MAY 11 2015
.SYNOPSIS...
UNSETTLED WEATHER MONDAY AND TUESDAY WILL PRECEDE A TUESDAY NIGHT
COLD FRONT. LESS HUMID AIR ARRIVES BY WEDNESDAY AND SHOULD LAST
INTO THURSDAY. THE LATTER PART OF THE WEEK AND WEEKEND WILL
FEATURE A GRADUAL INCREASE IN HUMIDITY AND THUNDERSTORM CHANCES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1000 AM MONDAY...FOR THE FIRST TIME IN WHAT SEEMS LIKE
AGES...TROPICAL STORM ANA IS NOT THE MAIN FORECAST CHALLENGE FOR THE
PERIOD. WHILE ANA REMAINS IN THE GENERAL VICINITY AS A TROPICAL
DEPRESSION LIFTING OFF INTO NE NORTH CAROLINA...HER SHOWERS AND
CLOUDS ARE CONFINED TO THE EXTREME NE PORTION OF THE CWA...AND THIS
WILL ERODE THROUGH LATE MORNING. AT THAT POINT ANA WILL FINALLY BE
DONE WITH THE WILMINGTON CWA.
BEHIND ANA...SURFACE RIDGE WILL BUILD INTO THE CWA CREATING A WARM
AND PARTLY SUNNY DAY - MORE SUN IN LOCATIONS WELL REMOVED FROM ANA -
BUT IN A STILL VERY MOIST ENVIRONMENT. TEMPS WILL SOAR QUICKLY THIS
MORNING THROUGH THE 70S AND INTO THE 80S...AND HIGHS THIS AFTN MAY
TOUCH 90 IN THE FAR SW ZONES...BUT ONLY INTO THE LOW 80S ALONG THE
COAST AS WELL AS IN THE NE ZONES. THIS SHOULD PROMOTE A SIGNIFICANT
RESULTANT SEA BREEZE BOUNDARY...AS WELL AS A PIEDMONT TROUGH. HIGH
RES GUIDANCE SUGGESTS THAT CONVECTION WILL RE-DEVELOP THIS AFTN AS A
WEAK SURFACE TROUGH LIFTS NE THROUGH THE CWA. WHILE SOME SUBSIDENCE
IS LIKELY BEHIND DEPARTING ANA...A VERY UNSTABLE AIRMASS (SBCAPE
NEAR 3000 J/KG) AND HIGH PWATS SHOULD PROMOTE SCATTERED TO MAYBE
WIDESPREAD CONVECTION LATE THIS AFTN...ESPECIALLY ACROSS WESTERN
ZONES. HEAVY RAINFALL IS THE MOST LIKELY THREAT...BUT SMALL HAIL
CANNOT BE RULED OUT THANKS TO SIGNIFICANT CAPE AS WELL IN THE -10 TO
-30 C HAIL GROWTH ZONE. FORTUNATELY...THE MOST WIDESPREAD ACTIVITY
IS EXPECTED IN PLACES THAT DID NOT RECEIVE THE TREMENDOUS RAINFALL
FROM ANA...SO FLOODING...WHILE STILL POSSIBLE...IS NOT EXPECTED TO
BE WIDESPREAD.
CONVECTION WILL WANE AFTER DARK WITH LOSS OF DIURNAL HEATING...BUT
RESIDUAL ELEVATED INSTABILITY COULD KEEP ISOLATED SHOWERS GOING
THROUGH THE NIGHT AND HAVE MAINTAINED SCHC POP THROUGH THE OVERNIGHT
HOURS. TEMPS TONIGHT WILL REMAIN QUITE WARM ON CONTINUED SW
FLOW...FALLING ONLY TO A DEGREE OR TWO EITHER SIDE OF 70.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 AM SUNDAY... A WARM AND HUMID AFTERNOON ON TUESDAY WILL LEAD
TO THE DEVELOPMENT OF 2000-2500 J/KG OF MLCAPE FOCUSED MAINLY OVER
NEERN ZONES INCLUDING CAPE FEAR REGION. THE LFC WILL BE AROUND KFT
AND WITH A HEALTHY BUT PINNED SEABREEZE AND WEAK SHORTWAVE WE SHOULD
BE ABLE TO LIFT A FEW PARCELS TO THAT LEVEL. THUS EXPECT SOME
HEALTHY UPDRAFTS MAINLY OVER EASTERN HALF OF THE CWA THOUGH AN
INLAND TROUGH COULD TOUCH OFF A FEW STORMS FURTHER WEST AS WELL. A
LITTLE BIT OF DIRECTIONAL SHEAR IN THE LOW LEVELS BUT DEEP LAYER
SHEAR A BIT TOO WEAK FOR ORGANIZED CONVECTION. HOWEVER GIVEN THE
STRENGTH OF THE INSTABILITY AND FAIRLY HIGH LIFTED INDICES A FEW
STORMS SEEM CAPABLE OF PULSING TO SEVERE LIMITS ESPECIALLY IF THERE
IS MORE SUNSHINE THAN ANTICIPATED...WHICH IS A DISTINCT POSSIBILITY
AS THE WESTERLY MID LEVEL DRYING LOOKS UNDERDONE IN FORECAST
SOUNDINGS. THE PREFRONTAL TROUGH GETS OVERTAKEN BY A COLD FRONT
TUESDAY NIGHT AS IT PUSHES THROUGH THE REGION. AND WHILE THE COOLING
BEHIND THIS BOUNDARY WILL ONLY BE MODEST THE DROP IN HUMIDITY WILL
BE MORE PRONOUNCED. THE MID AND UPPER LEVEL DRYING IS SIMILARLY
STRONG SO EXPECT A SEASONABLE, SUNNY, AND COMFORTABLY NON-HUMID
AFTERNOON.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 3 AM SUNDAY... MID LEVEL RIDGE OVERHEAD THURSDAY WHILE SURFACE
HIGH REMAINS TO OUR NORTH. LIKE WEDNESDAY WE EXPECT ANOTHER SUNNY
AND SEASONABLE DAY WITH FAIRLY LOW HUMIDITY. THIS WILL CHANGE
THURSDAY NIGHT INTO FRIDAY AS BOTH MOVE EASTWARD. THE WARMING WILL
BE RATHER GENTLE BUT THE HUMIDITY CREEPING UP MORE NOTICEABLE. THE
WEEKEND SHOULD THUS BRING FAIRLY SEASONABLE WARMTH AND HUMIDITY BUT
ALSO AT LEAST A SCATTERING OF MAINLY DIURNAL CONVECTION.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 18Z...THE HRRR MODEL SEEMS TO THINK WE WILL HAVE QUITE A BIT
OF CONVECTION THIS AFTERNOON...PARTICULARLY IN SOUTH CAROLINA. THERE
IS SOME SUBSIDENCE AROUND THE REMNANTS OF ANA...BUT THAT WILL BE
WANING THROUGH THE AFTERNOON HOURS SO SOME CONVECTION IS
EXPECTED...BUT WITH COVERAGE MAINLY CONFINED TO THE SEA BREEZE
BOUNDARY AND PLACES THAT RECEIVED FULL SUN TODAY. TONIGHT...MODELS
DO NOT SEEM TO THINK WE WILL SEE ANY FOG...BUT WITH ALL THE RAIN
THAT FELL ALONG THE COAST...EXPECT POSSIBLY SOME MVFR
FOG...ESPECIALLY HORRY AND BRUNSWICK COUNTIES. HOWEVER...RESIDUAL
WINDS AND LOW-LEVEL MOISTURE MAY DRIVE A STRATUS LAYER INSTEAD OF
FOG...AND HAVE SHOWN IFR IN ALL TAFS FOR LOW OVC. TUESDAY...CHANCES
FOR CONVECTION WILL INCREASE NEAR THE END OF THE FORECAST PERIOD
WITH A COLD FRONT.
EXTENDED OUTLOOK...SCATTERED SHOWERS POSSIBLE TUE EVENING AND AGAIN
ON FRIDAY. OTHERWISE EXPECT VFR..
&&
.MARINE... NEAR TERM /THROUGH TONIGHT/...
AS OF 1000 AM MONDAY...IMPROVING CONDITIONS ACROSS THE COASTAL
WATERS THIS MORNING AS TD ANA DEPARTS OFF TO THE NE. RESIDUAL HIGH
SEAS PERSIST ACROSS THE NC WATERS AND THE SCA REMAINS IN PLACE UNTIL
NOON TODAY. THE SCA FOR THE SC WATERS DROPPED AT 8AM. SEAS WILL
CONTINUE TO FALL AND WINDS WILL BECOME SWLY AT 10-15 KTS ACROSS ALL
THE WATERS THIS AFTN. THESE WINDS WILL THEN PERSIST THROUGH THE END
OF THE PERIOD...CREATING SEAS OF 2-4 FT TONIGHT.
SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 3 AM SUNDAY...SOUTHWESTERLY PRE-FRONTAL FLOW ON TUESDAY
WITH AN INLAND PIEDMONT TROUGH AND A FAIRLY PINNED SEA BREEZE. THE
GRADIENT MAY BECOME RATHER PINCHED ESPECIALLY TUESDAY NIGHT AT
WHICH TIME A COLD FRONT WILL OVERTAKE THE TROUGH AND PUSH ACROSS
THE WATERS. CURRENTLY IT APPEARS THAT THE RAPIDITY THAT THIS ALL
OCCURS PAIRED WITH THE MINIMAL ONSHORE FLOW COMPONENT THERE SHOULD
BE NO HEADLINES. BEHIND THE BOUNDARY A LIGHT NORTHERLY GRADIENT
WIND SETS UP AS HIGH PRESSURE REMAINS WELL REMOVED TO OUR NORTH.
WINDS BECOME QUITE LIGHT AND VARIABLE BY THE END OF THE PERIOD.
LONG TERM /THURSDAY THROUGH FRIDAY/...
AS OF 3 AM SUNDAY... THE HIGH LOCATED TO OUR NORTH DURING THE SHORT
TERM PROGRESSES EAST DURING THE LONG TERM. WINDS VEER FROM N TO E
EARLY IN THE PERIOD AND SHALL MORE OR LESS REMAIN SAVE FOR PERHAPS A
SLIGHT ADDITIONAL VEER TO SE BY FRIDAY. THERE WILL BE NO APPRECIABLE
SWELL ENERGY TO SPEAK OF SO THE FAIRLY MINOR WIND WAVES WILL BE THE
DOMINANT SEA STATE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MBB
NEAR TERM...JDW
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...43/JDW
MARINE...JDW/MBB
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
1252 AM EDT MON MAY 11 2015
.SYNOPSIS...
ANA WILL GRADUALLY WEAKEN AND LIFT NORTHEAST OVER THE COASTAL
PLAIN TONIGHT INTO MONDAY. A COLD FRONT APPROACHES FROM THE
NORTHWEST TUESDAY AND MOVES OFFSHORE WEDNESDAY. HIGH PRESSURE WILL
THEN BUILD IN FROM THE NORTH THROUGH THE END OF THE WEEK.
&&
.NEAR TERM /TONIGHT/...
AS OF 1 AM MON...NO BIG CHANGES TO FCST FOR THE REST OF TONIGHT
AS REMNANTS OF ANA MOVE NORTH NORTHEAST OVERNIGHT RAIN WILL
SPREAD INTO THE REMAINING COUNTIES. THEREFORE WILL LEAVE CAT TO
LIKELY POPS AS IS. REMNANTS OF ANA CURRENTLY OVER COASTAL PLAINS
SLOWLY LIFTING NORTH NORTHEAST WITH CONVECTIVE BANDS OF RAIN
SHOWERS WITH EMBEDDED THUNDER...HEAVY AT TIMES...EXPECTED FOR THE
REST OF TONIGHT. FFA CONTS FOR SW AREAS THRU 8 AM MON. ALSO...THERE
IS AN ISOLATED TOR THREAT ACRS ERN NC WITH FVRBL LOW LEVEL PROFILES
SSE SFC FLOW AND H8 WINDS VEERING SWLY. MUGGY TEMPS ARND 70
OVERNIGHT.
&&
.SHORT TERM /MONDAY/...
AS OF 345 PM SUN...SHOULD SEE THREAT FOR HEAVY RAIN SHOWERS END
THROUGH THE EARLY MORNING WITH PRECIP COVERAGE AND INTENSITY
TAPERING OFF SOMEWHAT AS REMNANTS OF THE SYSTEM WITH BEST LIFT
MOVE NORTHEAST INTO VA. STILL HUNG ONTO LIKELY POPS ACROSS THE
NORTH WITH HIGH CHANCE/SCT SOUTHERN AREAS. TEMPS WILL BE HELD DOWN
AGAIN WITH THE MOSTLY CLOUDY SKIES...THOUGH SOME SUN COULD BREAK
OUT ESP IN THE AFTERNOON WITH READINGS IN THE 80S ACROSS THE SW.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
REMNANT ANA LOW WILL BE MOVING WELL NORTH OF THE AREA MONDAY
NIGHT. HOWEVER A MOIST SW FLOW WILL REMAIN IN PLACE TUESDAY AHEAD
OF SHEARING UPPER TROF AND ASSOCD SFC COLD FRONT WITH CHANCES FOR
SCATTERED SHOWERS CONTINUING. MOIST BNDRY LAYER SUGGESTS MOCLDYSKIES
THRU TUESDAY MORNING THEN SUNNY BREAKS DEVELOP WITH MIXING
ALLOWING TEMPS TO SOAR TO NEAR 90 DEGREES INLAND TUESDAY
AFTERNOON. DESTABILIZATION AND SPEED SHEAR MAY BE SUPPORTIVE OF
STRONG TO SEVERE TSTORMS TUESDAY AFTERNOON INTO EVENING.
COLD FRONT SLIDES THRU THE AREA LATE TUESDAY NIGHT THEN UPPER RIDGE
BUILDS EAST WITH SFC HIGH RIDGING IN FROM THE NORTH. THE DRIER, MORE
STABLE AIRMASS WILL KEEP RAIN CHANCES AT BAY THRU AT LEAST THURSDAY
AND POSSIBLY THRU THE END OF THE WEEK UNLESS SHORT WAVE ENERGY/DEEP
MOISTURE CAN PENETRATE UPPER RIDGE MOVING OFFSHORE.
MAY BE INCREASINGLY UNSETTLED NEXT WEEKEND AS ZONAL FLOW AND STALLED
SFC BNDRY LINGER OVER THE AREA.
AFTER A HOT/HUMID TUESDAY, TEMPERATURES WILL SETTLE TO SLIGHTLY BLO
NORMAL LEVELS THRU THE END OF THE WEEK. TEMPS MAY REBOUND TO MORE
SEASONAL LEVELS NEXT WEEKEND DEPENDING ON PLACEMENT OF STALLED OUT
SFC FRONT.
&&
.AVIATION /04Z MONDAY THROUGH FRIDAY/...
SHORT TERM /TONIGHT THROUGH MONDAY/...
AS OF 1 AM MON...IFR/MVFR CONDITIONS OVER EASTERN NORTH CAROLINA
TAFS AS REMNANTS OF ANA OVER SE NORTH CAROLINA MOVES NORTH
NORTHEAST. HRRR HAS A GOOD HANDLE ON RAIN BANDS MOVING ACROSS THE
REGION THROUGH TONIGHT. TIMING OF BANDS WILL BE DIFFICULT TO
ACCURATELY PREDICT BUT AS REMNANTS OF ANA BECOME MORE
EXTRATROPICAL BANDED PRECIPITATION WILL BECOME MORE STRATIFORM
WITH LOWER CEILINGS. AS ANA PULLS AWAY WINDS WILL SHIFT TO THE SW
THEN W IN THE MORNING AFTER 12Z.
LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
ANA REMNANT LOW WILL BE MOVING WELL NORTH OF THE AREA MONDAY
NIGHT, HOWEVER RESIDUAL LOW LEVEL MOISTURE AND SCATTERED
PRECIPITATION MAY SUPPORT SUB-VFR CONDITIONS THRU TUESDAY MORNING.
MIXING WILL SCATTER OUT CLOUD COVER BY MIDDAY TUESDAY THEN
SCATTERED SHOWER AND THUNDERSTORMS (SOME OF WHICH CUD BE
STRONG/SEVERE) AFFECT THE AREA TUESDAY AFTERNOON AND EVENING.
DRYING AIRMASS BUILDS IN AFTER A COLD FRONT PASSAGE LATE TUESDAY
NIGHT WITH PREDOMINATE VFR EXPECTED THEREAFTER.
&&
.MARINE...
SHORT TERM /TONIGHT AND MONDAY/...
AS OF 1 AM MONDAY...LATEST LAND/BUOY OBS SHOW SOUTH TO SOUTHEAST
FLOW ACROSS THE MARINE ZONES...GENERALLY 10-20 KTS NORTH AND
15-25 KTS SOUTH WITH SEAS 3-7 FT. THE REMNANTS OF ANA WILL LIFT
NORTHEAST ACROSS THE COASTAL PLAIN OVERNIGHT WITH WINDS BECOMING
SOUTHERLY AND INCRG TO 15-25 KT ACROSS ALL WATERS AND PAMLICO
SOUND. SEAS BUILD TO 4-9 FT REST OF TONIGHT CONTG MON HIGHEST
CNTRL WATERS. SCA CONTS FOR ALL OF THE COASTAL WATERS INCLUDING
THE PAMLICO SOUND.
LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
DESPITE DEPARTING ANA, MARINE WEATHER REMAINS ACTIVE THRU MUCH OF
THIS WEEK. MODERATE TO STRONG SW WINDS AND LINGERING SEAS WILL
KEEP SMALL CRAFT ADVISORIES LIKELY THRU TUESDAY NIGHT AHEAD OF A
COLD FRONT PASSAGE LATE TUESDAY NIGHT OR EARLY WEDNESDAY. MAY BE A
LULL IN SMALL CRAFT ADVISORY CONDITIONS WEDNESDAY BEFORE STRONGER
POST FRONTAL N/NE WINDS KICK UP AGAIN WED NIGHT INTO THURSDAY.
WINDS/SEAS GRADUALLY RELAX THU NIGHT FRIDAY AS PRESSURE GRADIENT
DECREASES AT THE COAST WITH HIGH BUILDING IN FROM THE NORTH.
&&
.HYDROLOGY...
FLOOD WATCH ISSUED THROUGH MON MORNING AS OCCASIONAL BANDS OF
HEAVY SHOWERS PIVOT ACROSS E NC THROUGH LATE TONIGHT. THE HEAVIER
SHOWERS WILL PRODUCE RAIN RATES OF 1 INCH/HOUR OR HIGHER. HEAVIEST
RAIN THREAT LOOKS TO OCCUR OVERNIGHT TONIGHT.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...FLOOD WATCH UNTIL 8 AM EDT THIS MORNING FOR NCZ090>093-095-098.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 AM EDT WEDNESDAY FOR AMZ135-150.
SMALL CRAFT ADVISORY UNTIL 8 AM EDT WEDNESDAY FOR AMZ152-154.
SMALL CRAFT ADVISORY UNTIL 4 AM EDT WEDNESDAY FOR AMZ156-158.
&&
$$
SYNOPSIS...TL
NEAR TERM...JAC/HSA/TL
SHORT TERM...TL
LONG TERM...BTC
AVIATION...JAC/BTC/HSA
MARINE...JAC/BTC/HSA/TL
HYDROLOGY...TL/RF
AREA FORECAST DISCUSSION
NWS BISMARCK ND
947 PM CDT TUE MAY 12 2015
.UPDATE...
ISSUED AT 938 PM CDT TUE MAY 12 2015
AT 930 PM CDT...BAND OF SHOWERS CONTINUES TO TREND NORTH AND EAST
NOW ALONG A LAKE SAKAKAWEA SOUTHEAST INTO JAMESTOWN LINE. WILL
TREND THE HIGHER POPS SLOWLY EAST NORTHEAST THROUGH THE REMAINDER
OF THE EVENING. AFTER MIDNIGHT MODELS DEPICT LIFT OVER A WARM
FRONT ACROSS SOUTH DAKOTA THAT WILL FAVOR INCREASED CLOUDS AND
SCATTERED SHOWERS OVER THE REGION AS THE CURRENT FORECAST HAS
GOING.
UPDATE ISSUED AT 654 PM CDT TUE MAY 12 2015
BAND OF RAIN SHOWERS MOVING THROUGH CENTRAL NORTH DAKOTA. UPDATED
THE POPS/SKY GRIDS BASED ON THESE HRRR TRENDS. FOCUSED HIGHEST
POPS EAST OF BISMARCK FOR THE EVENING.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 259 PM CDT TUE MAY 12 2015
FORECAST HIGHLIGHTS IN THE SHORT TERM PERIOD WILL BE PRECIPITATION
CHANCES THROUGH THE PERIOD.
CURRENTLY...ZONAL FLOW ALOFT WITH A CLOSED MID LEVEL LOW OVER FAR
SOUTH CENTRAL CANADA AND A RIDGE AXIS STRETCHING FROM THE CENTRAL
PLAINS NORTHWEST INTO SOUTHERN MONTANA. EMBEDDED S/WV IMPULSE
MOVING ALONG THE ND/SD BORDER WILL BRING A DECENT CHANCE FOR
SHOWERS TO SOUTHERN PORTIONS OF NORTH DAKOTA THIS AFTERNOON AND
EVENING. EXPECT MOISTURE TO REMAIN BELOW A TENTH OF AN INCH...WITH
MOST LOCATIONS SEEING A TRACE OR PERHAPS A FEW HUNDRETHS.
CLOUDS AND CHANCES FOR SHOWERS CONTINUE TONIGHT WITH MODELS
DEPICTING SEVERAL SMALL-SCALE EMBEDDED WAVES PUSHING EAST ACROSS
THE REGION ALONG WITH A PERSISTENT AND MOIST EAST/SOUTHEASTERLY
LOW/MID LEVEL FLOW REGIME. MODELS ARE KEYING IN ON MY NORTH
CENTRAL AND EAST TONIGHT FOR BEST CHANCES AND HIGHEST MOISTURE
WHERE BEST FORCING WILL RESIDE. LOWS TONIGHT MAINLY IN THE 40S.
FOR WEDNESDAY...WARM FRONTAL BOUNDARY NOW OVER SOUTHERN SOUTH
DAKOTA WILL LIFT SLOWLY NORTH LATER TONIGHT INTO
WEDNESDAY...REACHING THE ND/SD BORDER MID TO LATE AFTERNOON. ALONG
THE WARM FRONT MUCAPE 500-1200 J/KG WILL SLOWLY CREEP INTO MY FAR
SOUTHWEST AND FAR SOUTH CENTRAL COUNTIES. 0-6KM SHEAR MODEST AT
25-35KTS DEPENDING ON WHICH MODELS IS USED. SO THERE APPEARS TO BE
SOME POTENTIAL FOR STRONG CONVECTION AND WILL BE WORTH LOOKING
MORE CLOSELY AT OVER THE NEXT 12-18 HOURS TO SEE HOW MODELS
TREND.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 259 PM CDT TUE MAY 12 2015
UNSETTLED WEATHER REMAINS ON TRACK WITH RAIN SHOWERS AND A CHANCE OF
THUNDERSTORMS WEDNESDAY NIGHT INTO THURSDAY...FOLLOWED BY A BRIEF
BREAK THURSDAY NIGHT THROUGH MOST OF FRIDAY. THEN A SIGNIFICANT
WEATHER SYSTEM/VERTICALLY STACKED AND SLOW MOVING OVER THE WEEKEND
LOOKS TO PRODUCE WIDESPREAD RAIN SHOWERS AND POSSIBLY SEVERE
THUNDERSTORMS. DRIER WEATHER MONDAY AND TUESDAY.
WEDNESDAY NIGHT THROUGH THURSDAY...A 700MB UPPER LOW WITH A SURFACE
REFLECTION/WARM FRONT STRETCHING FROM CENTRAL SOUTH DAKOTA INTO
SOUTH CENTRAL NORTH DAKOTA WILL SHIFT EAST THROUGH THURSDAY. HIGH
CHANCE TO LIKELY POPS ACROSS CENTRAL NORTH DAKOTA WITH CHANCES
DECREASING FARTHER WEST. MOST UNSTABLE CAPE ACROSS SOUTHWEST INTO
SOUTH CENTRAL NORTH DAKOTA AROUND 500 J/KG WITH 0-6KM BULK SHEAR
EARLY WEDNESDAY NIGHT AT AROUND 25-30KT...THEN DECREASING THE REST
OF WEDNESDAY NIGHT INTO THURSDAY. WILL CONTINUE TO MENTION A CHANCE
FOR THUNDERSTORMS WEDNESDAY NIGHT BUT LEAVE OUT ANY MENTION ON
THURSDAY.
THURSDAY NIGHT THROUGH FRIDAY...A TRANSITORY MID LEVEL RIDGE SLIDES
THROUGH CENTRAL NORTH DAKOTA FRIDAY AFTERNOON ALLOWING MOISTURE AND
THE NEXT POTENT MID/UPPER LEVEL SHORTWAVE IN WYOMING TO IMPINGE
ACROSS SOUTHWESTERN NORTH DAKOTA FRIDAY AFTERNOON. CAPE VALUES
FORECAST NEAR 1000 J/KG IN THE FAR SOUTHWEST WITH AROUND 25KT OF 0-
6KM BULK SHEAR. HENCE WILL MENTION A CHANCE OF THUNDERSTORMS IN THIS
AREA FRIDAY AFTERNOON WITH SHOWERS ELSEWHERE IN THE WEST AND
PORTIONS OF SOUTH CENTRAL NORTH DAKOTA.
FRIDAY NIGHT THROUGH SUNDAY NIGHT...A POTENT CLOSED/VERTICALLY
STACKED UPPER LOW IS FORECAST TO TRANSLATE FROM SOUTHEAST MONTANA
FRIDAY NIGHT...ACROSS NORTHERN SOUTH DAKOTA SATURDAY NIGHT...AND
THEN INTO WESTERN MINNESOTA SUNDAY NIGHT. FRIDAY NIGHT THROUGH
SATURDAY NIGHT...THE TRACK OF THE UPPER LOW/SURFACE LOW PUTS MOST OF
CENTRAL AND SOUTHERN NORTH DAKOTA IN THE WARM SECTOR. UNCERTAINTY
REMAINS ON HOW MUCH OF A DRY SLOT...IF ANY...WILL WORK ITS WAY INTO
SOUTHERN/CENTRAL NORTH DAKOTA. SEVERE WEATHER IS POSSIBLE SATURDAY
INTO SATURDAY NIGHT. DETAILS ON EXACTLY WHERE THIS WILL OCCUR STILL
IN QUESTION PER 12Z GFS AND 12Z ECMWF. WITH THE SURFACE LOW AND WARM
FRONTAL POSITION LOCATED OVER SOUTH CENTRAL NORTH DAKOTA SATURDAY
AFTERNOON...THE BEST INSTABILITY AND SHEAR RESIDES ALONG AND
NORTH...WHICH WOULD PLACE NORTHWEST/NORTH CENTRAL/AND THE JAMES
RIVER VALLEY IN A PRIME LOCATION. THE GFS PORTRAYS THIS MORE THAN
THE ECMWF. THE ECMWF KEEPS THE GREATEST INSTABILITY AND SHEAR MAINLY
OVER SOUTH CENTRAL NORTH DAKOTA AND THE JAMES RIVER VALLEY. THIS
WILL LIKELY CHANGE OVER THE COMING DAYS...SO WILL BE ABLE TO HONE IN
ON THIS MORE IN THE NEXT FEW DAYS. CAPE VALUES ARE FORECAST BETWEEN
1000-2000 J/KG WITH 0-6KM BULK SHEAR OF 35KT TO 45KT IN THE GREATEST
AREAS OF INSTABILITY ON BOTH MODELS. WILL CONTINUE TO CLOSELY
MONITOR.
MONDAY INTO TUESDAY...BOTH THE GFS AND ECMWF SHOW THE WEEKEND STORM
DEPARTING SUNDAY NIGHT LEAVING MONDAY/MONDAY NIGHT DRY WITH A
TRANSITORY 700MB-500MB RIDGE MIGRATING FROM SOUTHWEST TO NORTHEAST.
ANOTHER UPPER LOW IS FORECAST TO FOLLOW A SIMILAR PATH FOR TUESDAY
AND WEDNESDAY WITH POTENTIALLY ANOTHER WIDESPREAD PRECIPITATION
EVENT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 654 PM CDT TUE MAY 12 2015
AT 6 PM CDT...A SURFACE TROUGH OF LOW PRESSURE EXTENDED ACROSS
WYOMING AND SOUTH DAKOTA AND WAS MOVING NORTH. HIGH CONFIDENCE IN
SHORT TERM TRENDS AS BAND OF SHOWERS WITH VFR CONDITIONS MOVES
NORTHEAST FROM A BEULAH TO BISMARCK TO JAMESTOWN LINE THROUGH
06Z. AFTER THIS TIME SHORT TERM MODELS FAVOR DEVELOPMENT OF MVFR
CONDITIONS FROM KISN-KMOT-KJMS WITH GENERALLY VFR KDIK-KBIS. SOME
UNCERTAINTY HOW FAR SOUTH MVFR CLOUDS WILL TREND AS EASTERLY WINDS
WITH SURFACE TROUGH TO THE SOUTH OFTEN FAVOR LOWER CLOUDS RETURNING
SOUTH.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...WAA
SHORT TERM...NH
LONG TERM...KS
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
707 PM CDT TUE MAY 12 2015
.UPDATE...
ISSUED AT 654 PM CDT TUE MAY 12 2015
BAND OF RAIN SHOWERS MOVING THROUGH CENTRAL NORTH DAKOTA. UPDATED
THE POPS/SKY GRIDS BASED ON THESE HRRR TRENDS. FOCUSED HIGHEST
POPS EAST OF BISMARCK FOR THE EVENING.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 259 PM CDT TUE MAY 12 2015
FORECAST HIGHLIGHTS IN THE SHORT TERM PERIOD WILL BE PRECIPITATION
CHANCES THROUGH THE PERIOD.
CURRENTLY...ZONAL FLOW ALOFT WITH A CLOSED MID LEVEL LOW OVER FAR
SOUTH CENTRAL CANADA AND A RIDGE AXIS STRETCHING FROM THE CENTRAL
PLAINS NORTHWEST INTO SOUTHERN MONTANA. EMBEDDED S/WV IMPULSE
MOVING ALONG THE ND/SD BORDER WILL BRING A DECENT CHANCE FOR
SHOWERS TO SOUTHERN PORTIONS OF NORTH DAKOTA THIS AFTERNOON AND
EVENING. EXPECT MOISTURE TO REMAIN BELOW A TENTH OF AN INCH...WITH
MOST LOCATIONS SEEING A TRACE OR PERHAPS A FEW HUNDRETHS.
CLOUDS AND CHANCES FOR SHOWERS CONTINUE TONIGHT WITH MODELS
DEPICTING SEVERAL SMALL-SCALE EMBEDDED WAVES PUSHING EAST ACROSS
THE REGION ALONG WITH A PERSISTENT AND MOIST EAST/SOUTHEASTERLY
LOW/MID LEVEL FLOW REGIME. MODELS ARE KEYING IN ON MY NORTH
CENTRAL AND EAST TONIGHT FOR BEST CHANCES AND HIGHEST MOISTURE
WHERE BEST FORCING WILL RESIDE. LOWS TONIGHT MAINLY IN THE 40S.
FOR WEDNESDAY...WARM FRONTAL BOUNDARY NOW OVER SOUTHERN SOUTH
DAKOTA WILL LIFT SLOWLY NORTH LATER TONIGHT INTO
WEDNESDAY...REACHING THE ND/SD BORDER MID TO LATE AFTERNOON. ALONG
THE WARM FRONT MUCAPE 500-1200 J/KG WILL SLOWLY CREEP INTO MY FAR
SOUTHWEST AND FAR SOUTH CENTRAL COUNTIES. 0-6KM SHEAR MODEST AT
25-35KTS DEPENDING ON WHICH MODELS IS USED. SO THERE APPEARS TO BE
SOME POTENTIAL FOR STRONG CONVECTION AND WILL BE WORTH LOOKING
MORE CLOSELY AT OVER THE NEXT 12-18 HOURS TO SEE HOW MODELS
TREND.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 259 PM CDT TUE MAY 12 2015
UNSETTLED WEATHER REMAINS ON TRACK WITH RAIN SHOWERS AND A CHANCE OF
THUNDERSTORMS WEDNESDAY NIGHT INTO THURSDAY...FOLLOWED BY A BRIEF
BREAK THURSDAY NIGHT THROUGH MOST OF FRIDAY. THEN A SIGNIFICANT
WEATHER SYSTEM/VERTICALLY STACKED AND SLOW MOVING OVER THE WEEKEND
LOOKS TO PRODUCE WIDESPREAD RAIN SHOWERS AND POSSIBLY SEVERE
THUNDERSTORMS. DRIER WEATHER MONDAY AND TUESDAY.
WEDNESDAY NIGHT THROUGH THURSDAY...A 700MB UPPER LOW WITH A SURFACE
REFLECTION/WARM FRONT STRETCHING FROM CENTRAL SOUTH DAKOTA INTO
SOUTH CENTRAL NORTH DAKOTA WILL SHIFT EAST THROUGH THURSDAY. HIGH
CHANCE TO LIKELY POPS ACROSS CENTRAL NORTH DAKOTA WITH CHANCES
DECREASING FARTHER WEST. MOST UNSTABLE CAPE ACROSS SOUTHWEST INTO
SOUTH CENTRAL NORTH DAKOTA AROUND 500 J/KG WITH 0-6KM BULK SHEAR
EARLY WEDNESDAY NIGHT AT AROUND 25-30KT...THEN DECREASING THE REST
OF WEDNESDAY NIGHT INTO THURSDAY. WILL CONTINUE TO MENTION A CHANCE
FOR THUNDERSTORMS WEDNESDAY NIGHT BUT LEAVE OUT ANY MENTION ON
THURSDAY.
THURSDAY NIGHT THROUGH FRIDAY...A TRANSITORY MID LEVEL RIDGE SLIDES
THROUGH CENTRAL NORTH DAKOTA FRIDAY AFTERNOON ALLOWING MOISTURE AND
THE NEXT POTENT MID/UPPER LEVEL SHORTWAVE IN WYOMING TO IMPINGE
ACROSS SOUTHWESTERN NORTH DAKOTA FRIDAY AFTERNOON. CAPE VALUES
FORECAST NEAR 1000 J/KG IN THE FAR SOUTHWEST WITH AROUND 25KT OF 0-
6KM BULK SHEAR. HENCE WILL MENTION A CHANCE OF THUNDERSTORMS IN THIS
AREA FRIDAY AFTERNOON WITH SHOWERS ELSEWHERE IN THE WEST AND
PORTIONS OF SOUTH CENTRAL NORTH DAKOTA.
FRIDAY NIGHT THROUGH SUNDAY NIGHT...A POTENT CLOSED/VERTICALLY
STACKED UPPER LOW IS FORECAST TO TRANSLATE FROM SOUTHEAST MONTANA
FRIDAY NIGHT...ACROSS NORTHERN SOUTH DAKOTA SATURDAY NIGHT...AND
THEN INTO WESTERN MINNESOTA SUNDAY NIGHT. FRIDAY NIGHT THROUGH
SATURDAY NIGHT...THE TRACK OF THE UPPER LOW/SURFACE LOW PUTS MOST OF
CENTRAL AND SOUTHERN NORTH DAKOTA IN THE WARM SECTOR. UNCERTAINTY
REMAINS ON HOW MUCH OF A DRY SLOT...IF ANY...WILL WORK ITS WAY INTO
SOUTHERN/CENTRAL NORTH DAKOTA. SEVERE WEATHER IS POSSIBLE SATURDAY
INTO SATURDAY NIGHT. DETAILS ON EXACTLY WHERE THIS WILL OCCUR STILL
IN QUESTION PER 12Z GFS AND 12Z ECMWF. WITH THE SURFACE LOW AND WARM
FRONTAL POSITION LOCATED OVER SOUTH CENTRAL NORTH DAKOTA SATURDAY
AFTERNOON...THE BEST INSTABILITY AND SHEAR RESIDES ALONG AND
NORTH...WHICH WOULD PLACE NORTHWEST/NORTH CENTRAL/AND THE JAMES
RIVER VALLEY IN A PRIME LOCATION. THE GFS PORTRAYS THIS MORE THAN
THE ECMWF. THE ECMWF KEEPS THE GREATEST INSTABILITY AND SHEAR MAINLY
OVER SOUTH CENTRAL NORTH DAKOTA AND THE JAMES RIVER VALLEY. THIS
WILL LIKELY CHANGE OVER THE COMING DAYS...SO WILL BE ABLE TO HONE IN
ON THIS MORE IN THE NEXT FEW DAYS. CAPE VALUES ARE FORECAST BETWEEN
1000-2000 J/KG WITH 0-6KM BULK SHEAR OF 35KT TO 45KT IN THE GREATEST
AREAS OF INSTABILITY ON BOTH MODELS. WILL CONTINUE TO CLOSELY
MONITOR.
MONDAY INTO TUESDAY...BOTH THE GFS AND ECMWF SHOW THE WEEKEND STORM
DEPARTING SUNDAY NIGHT LEAVING MONDAY/MONDAY NIGHT DRY WITH A
TRANSITORY 700MB-500MB RIDGE MIGRATING FROM SOUTHWEST TO NORTHEAST.
ANOTHER UPPER LOW IS FORECAST TO FOLLOW A SIMILAR PATH FOR TUESDAY
AND WEDNESDAY WITH POTENTIALLY ANOTHER WIDESPREAD PRECIPITATION
EVENT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 654 PM CDT TUE MAY 12 2015
AT 6 PM CDT...A SURFACE TROUGH OF LOW PRESSURE EXTENDED ACROSS
WYOMING AND SOUTH DAKOTA AND WAS MOVING NORTH. HIGH CONFIDENCE IN
SHORT TERM TRENDS AS BAND OF SHOWERS WITH VFR CONDITIONS MOVES
NORTHEAST FROM A BEULAH TO BISMARCK TO JAMESTOWN LINE THROUGH
06Z. AFTER THIS TIME SHORT TERM MODELS FAVOR DEVELOPMENT OF MVFR
CONDITIONS FROM KISN-KMOT-KJMS WITH GENERALLY VFR KDIK-KBIS. SOME
UNCERTAINTY HOW FAR SOUTH MVFR CLOUDS WILL TREND AS EASTERLY WINDS
WITH SURFACE TROUGH TO THE SOUTH OFTEN FAVOR LOWER CLOUDS RETURNING
SOUTH.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...WAA
SHORT TERM...NH
LONG TERM...KS
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
129 AM CDT MON MAY 11 2015
.UPDATE...
ISSUED AT 1237 AM CDT MON MAY 11 2015
THE MAIN FOCUS TONIGHT WILL BE SNOW ACCUMULATIONS. A SECONDARY
SURGE OF WARM/MOIST AIR AND ASSOCIATED CONVECTION IS ONGOING
ACROSS NORTH CENTRAL SOUTH DAKOTA AND SOUTH CENTRAL/SOUTHEAST
NORTH DAKOTA. THERE IS SOME CONCERN THAT ALL PRECIPITATIN WILL
REFOCUS THERE AND NECESSITATE CANCELLATION OF THE NORTHERN HALF OF
ADVISORIES. THE 12 UTC WRF ARW ALSO PUSHES THE WESTERN EDGE OF
SNOW WESTWARD BACK INTO ADAMS AND HETTINGER COUNTIES. THUS...WILL
NEED TO EXAMINE RADAR AND SATELLITE TRENDS OVER THE NEXT COUPLE
HOURS AND MAKE DECISIONS FOR THE 4 AM CDT ISSUANCE.
UPDATE ISSUED AT 932 PM CDT SUN MAY 10 2015
CONSIDERED BRIEFLY EXPANDING THE WARNING EAST A FEW COUNTIES. AFTER
CLOSE SCRUTINY OF SURFACE REPORTS WHICH ARE ALL RAIN AT THIS
TIME...CANNOT SEE ENOUGH REASON TO EXPAND THE WARNING EAST AND
NORTH. WILL LEAVE AS IS. CURRENT HRRR TRENDS DEFINITELY SHOW
INCREASING MOISTURE. BUT NAM ALSO HAS H850 TEMPS INCREASING A
DEGREE OR SO. SO DO NOT THINK THE PRECIP WILL TURN OVER TO SNOW
EARLY ENOUGH TO WARRANT EXPANSION OF THE WARNING. THINK THE
ADVISORY SHOULD COVER. CURRENT FORECAST HEADLINES LOOK GOOD. WILL
SEE RAIN CHANGE TO SNOW AFTER MIDNIGHT.
UPDATE ISSUED AT 719 PM CDT SUN MAY 10 2015
LATEST RADAR TRENDS SHOW A MOISTURE CONVEYOR FROM NORTHEAST SOUTH
DAKOTA INTO CENTRAL NORTH DAKOTA. HRRR MODEL FORECASTS A H700 LOW
TO DEEPEN AND CLOSE OFF AS IT MOVES NORTHEAST INTO SOUTHEAST
NORTH DAKOTA DURING THE NEXT 9 HOURS. THIS SHOULD SET UP
INCREASING PRECIPITATION ACROSS SOUTH CENTRAL THROUGH THE JAMES
RIVER VALLEY. WILL HAVE TO MONITOR SNOW AND RAIN AREAS CLOSELY.
NO CHANGES AT THIS TIME.
UPDATE ISSUED AT 412 PM CDT SUN MAY 10 2015
ADDED A SLIGHT CHANCE OF THUNDERSTORMS TO LAMOURE AND DICKEY
COUNTIES. SEVERAL CELLS ARE MOVING NORTH FROM NORTHEAST SOUTH
DAKOTA. THIS SHOULD LAST THROUGH 7 PM.
&&
.SHORT TERM...(THIS AFTERNOON THROUGH MONDAY)
ISSUED AT 305 PM CDT SUN MAY 10 2015
WINTER STORM MAIN HIGHLIGHT FOR THE SHORT TERM PERIOD.
CURRENTLY...INITIAL DEFORMATION ZONE CONTINUES BUT HAS SHOWN
SIGNS OF DISSIPATION THE LAST HOUR OR TWO ACROSS SOUTH CENTRAL
NORTH DAKOTA. DRY SLOT WORKING NORTH INTO MY SOUTHEAST WITH ONLY
ISOLATED RADAR RETURNS NOW. PRECIP TYPE HAS BEEN BOUNCING AROUND
FROM RAIN OR SNOW MANY PLACES. THE EXCEPTION WAS ACROSS PARTS OF
THE SOUTH CENTRAL WHERE 8 INCHES WAS REPORTED EARLIER IN SELFRIDGE
AND 3-5 FROM HAZELTON...WISHEK...NAPOLEON AND STRASBURG.
ALL MODELS DEPICT ANOTHER DEFORMATION ZONE AND MOISTURE SURGE
ACROSS MY SOUTHEASTERN THIRD...MAINLY EAST AND SOUTHEAST OF
BISMARCK. QUESTION IS THE EXACT PLACEMENT OF THIS FEATURE AND HOW
MUCH QPF AND/OR SNOW WILL FALL TONIGHT. CURRENTLY HAVE ANOTHER 5
INCHES FORECAST ON TOP OF THE 3-5 WHICH ALREADY OCCURRED...BUT
EVEN THIS IS QUESTIONABLE WITH THE GREAT UNCERTAINTY WITH
TEMPERATURES. OVERALL DID NOT FEEL CONFIDENT ENOUGH TO UPGRADE
KIDDER...EMMONS...LOGAN...AND MCINTOSH TO A WARNING AND WILL LEAVE
THEM IN AN ADVISORY. THE EVENING SHIFT WILL CLOSELY MONITOR SO AN
UPGRADE IS STILL POSSIBLE OVER THE NEXT SEVERAL HOURS.
NOT MUCH AT ALL OCCURRED IN THE SOUTHWEST TODAY SO REMOVED
BOWMAN...SLOPE...AND STARK FROM HEADLINES...AND TRANSITIONED ADAMS
AND HETTINGER INTO AN ADVISORY WITH ONLY 3-4 INCHES REPORTS AND
ZERO IMPACTS.
WRAP AROUND RAIN/SNOW SLOWLY MOVES EAST TONIGHT INTO MONDAY
MORNING...EXITING OFF TO OUR EAST LATE MONDAY INTO MONDAY EVENING.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 253 PM CDT SUN MAY 10 2015
ACTIVE FLOW ALOFT WILL PRODUCE FREQUENT CHANCES FOR WIDESPREAD
PRECIPITATION THROUGH THE EXTENDED.
CHANCES FOR RAIN AND SNOW ARE EXPECTED TO LINGER OVER EASTERN AREAS
OF THE STATE THROUGH MONDAY NIGHT...AS A BROAD UPPER LEVEL TROUGH
CONTINUES TO SLOWLY MOVE EASTWARD ACROSS THE NORTHERN PLAINS.
THE CURRENT DETERMINISTIC AND ENSEMBLE MODELS ARE PROJECTING
SOUTHWEST FLOW ALOFT BY WEDNESDAY AND CONTINUING INTO SATURDAY. AS A
RESULT...LEE TROUGHING IS EXPECTED AT THE SURFACE WITH MOISTURE
TRANSPORT AND ATMOSPHERIC INSTABILITY CREATING NUMEROUS CHANCES FOR
WIDESPREAD SHOWERS AND THUNDERSTORMS.
CONTINUED CHANCES FOR WIDESPREAD PRECIPITATION ARE POSSIBLE...AS
ANOTHER UPPER LEVEL LOW IS PROJECTED OVER THE NORTHERN PLAINS BY
THE END OF THE PERIOD...MODELS ARE VARIED ON TIMING/LOCATION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1237 AM CDT MON MAY 11 2015
THERE IS A LARGE SPRING STORM PRODUCING WIDESPREAD IFR CONDITIONS
ACROSS SOUTH CENTRAL AND SOUTHEAST NORTH DAKOTA. KBIS-KJMS WILL
GENERALLY REMAIN IFR IN RAIN AND SNOW CHANGING TO ALL SNOW THROUGH
THE NIGHT. CONDITIONS IMPROVING TO MVFR MONDAY. KISN-KMOT WILL
REMAIN NORTH OF THE STORM WITH VFR. KDIK WILL SEE MVFR IMPROVING
TO VFR AFTER 09Z.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 7 AM CDT /6 AM MDT/ THIS MORNING
FOR NDZ020-041-044.
WINTER WEATHER ADVISORY UNTIL 7 PM CDT THIS EVENING FOR NDZ022-
023-025-035>037-046-047-050.
WINTER STORM WARNING UNTIL 7 AM CDT /6 AM MDT/ THIS MORNING FOR
NDZ034-042-045.
&&
$$
UPDATE...SCHECK
SHORT TERM...NH
LONG TERM...AC
AVIATION...SCHECK
AREA FORECAST DISCUSSION
NWS PENDLETON OR
615 PM PDT TUE MAY 12 2015
.SHORT TERM...TONIGHT AND WEDNESDAY...UPPER LEVEL LOW PRESSURE
SYSTEM CONTINUES TO IMPACT THE REGION. A SURGE OF SHORTWAVE ENERGY
WRAPPING AROUND THE LOW IS COMING UP OUT OF NORTHWEST NEVADA WHICH
IS ACTING TO ENHANCE CONVECTIVE SHOWERS OVER FAR EASTERN OREGON.
THIS SHORTWAVE WILL PIVOT INTO NORTHEAST OREGON OVERNIGHT AND THEN
INTO EASTERN WASHINGTON EARLY WEDNESDAY. THE SHOWERS BEING GENERATED
AHEAD OF THIS SHORTWAVE ARE EXPECTED TO CONTINUE TO ENHANCE AND
BECOME MORE CLUSTERED TOGETHER AS A PRECIPITATION SHIELD. THIS AREA
OF PRECIPITATION HAS THE POTENTIAL TO PRODUCE SOME SIGNIFICANT
AMOUNTS OF RAIN AS IT PASSES THROUGH THE FORECAST AREA OVERNIGHT AND
WEDNESDAY ON THE ORDER OF AROUND HALF AN INCH IN THE LOW ELEVATIONS
AND AN INCH OR MORE IN THE MOUNTAINS. FORECAST HAS BEEN UPDATED TO
INCREASE THE CHANCE OF PRECIPITATION AND AMOUNT OF PRECIPITATION
OVERNIGHT AND WEDNESDAY.
.
&&
.PREV DISCUSSION... /ISSUED 351 PM PDT TUE MAY 12 2015/
SHORT TERM...TUESDAY NIGHT THROUGH THURSDAY NIGHT. AN INTENSE AND
STATIONARY LOW PRESSURE SYSTEM OVER THE PACNW WILL CONTINUE TO PUMP
MOISTURE INTO OUR AREA AND COMBINING THIS WITH DAYTIME HEATING WILL
PRODUCE ISOLATED THUNDERSTORMS THIS AFTERNOON AND EVENING. THE TSRA
COULD BECOME STRONG AND PRODUCE GUSTY WINDS AND HAIL WITH THE BEST
CHANCES OF THIS OCCURRING OVER THE EASTERN ZONES THAT INCLUDES IN
AND AROUND THE BLUE/WALLOWA MOUNTAINS AS WELL AS GRANT COUNTY.
ELSEWHERE SHOWERS WILL CONTINUE DEVELOPING ACROSS THE REGION INTO
THIS EVENING. AS THE LOW DRIFTS INTO NE OREGON LATER TONIGHT
MOISTURE WILL RAP AROUND THIS SYSTEM AND INTO THE EASTERN PORTIONS
OF THE AREA AND MODERATE TO HEAVY RAINFALL IS POSSIBLE WITH UP TO AN
INCH IN SOME LOCATIONS. THE LOW AND THE BULK OF THE MOISTURE DRIFT
NORTH WEDNESDAY MORNING WITH DECREASING CHANCES OF PCPN EXPECTED BUT
THE CLOUDS AND SHOWERS WILL PERSIST INTO WEDNESDAY AFTERNOON. A WEAK
DISTURBANCE WILL NEAR CENTRAL OREGON WEDNESDAY AFTERNOON THAT COULD
PRODUCE AN ISOLD TSRA. OTHERWISE THE BEST CHANCES FOR PCPN SHOULD
OCCUR ALONG THE WA/OR CASCADES WEDNESDAY NIGHT AND THURSDAY.
BY THURSDAY ANOTHER LOW PRESSURE SYSTEM WILL TRACK TO OUR SOUTH BUT
SHOWERS FROM THIS SYSTEM WILL MOVE NORTH AND INTO MOST PORTIONS OF
OUR AREA THURSDAY NIGHT. AFTERNOON TEMPERATURES WILL REMAIN COOL
TOMORROW BEFORE WARMER TEMPERATURES CAN BE EXPECTED THURSDAY.
LONG TERM...FRIDAY THROUGH MONDAY NIGHT...MILD YET UNSETTLED
WEATHER CAN BE EXPECTED FOR THE EXTENDED. A LOW PRESSURE SYSTEM
CENTERED OVER CENTRAL NEVADA WILL CONTINUE TO SPIN UP MOISTURE AND
POSSIBLE THUNDERSTORMS TO THE AREA ON FRIDAY. THIS SYSTEM WILL EXIT
THE AREA FRIDAY NIGHT WITH ANOTHER LOW MOVING TOWARDS THE PACIFIC
COAST ON SATURDAY. THIS LOW IS CURRENTLY FORECAST TO TRACK SOUTH OF
THE CWA TOWARDS THE NORTHERN CALIFORNIA COAST THROUGH THE WEEKEND.
THIS WILL ALLOW FOR MORE MOISTURE AND INSTABILITY TO BE SPUN UP OVER
THE AREA...PROVIDING ANOTHER CHANCE FOR THUNDERSTORMS. THE LOW IS
EXPECTED TO SLOWLY MOVE INLAND AND BE CENTERED OVER THE CA/NV
BOARDER ON MONDAY NIGHT. OVERALL THE AIRMASS SHOULD BE FAIRLY WARM
OVER THE AREA...KEEPING THE TEMPERATURES NEAR TO ABOVE NORMAL.
REASONABLE CLOUD COVER CAN BE EXPECTED AT NIGHT AS WELL...ALLOWING
FOR MILD NIGHTTIME LOWS. WEBER
AVIATION...00Z TAFS...MVFR CONDITIONS CAN BE EXPECTED OVER THE NEXT
12-18 HOURS...AS A DEFORMATION BAND IS EXPECTED TO SET UP OVER
SOUTHERN WASHINGTON DURING THIS PERIOD. THIS COULD ALLOW FOR
PERIODS OF MODERATE RAIN...WITH CIGS POSSIBLY FALLING TO IFR
CATEGORIES. FOR NOW PROB30 GROUPS COVER THE PERIODS OF CONCERN.
STILL POSSIBLE -TSRA AT KPDT AND KALW FROM 0Z-3Z THIS
AFTERNOON...BUT DUE TO LOWER CONFIDENCE HAVE REMOVED THE TEMPO GROUP
FOR THUNDER AND JUST LEFT SHOWERS. WINDS WILL RANGE FROM 5 TO 15
KTS...WITH GUSTS UP TO 25 KTS. WEBER
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 46 62 45 64 / 100 80 10 30
ALW 48 63 46 69 / 100 90 10 30
PSC 52 64 46 70 / 100 90 10 20
YKM 50 59 43 70 / 90 90 40 20
HRI 50 64 44 70 / 100 90 10 30
ELN 47 57 41 70 / 90 90 40 20
RDM 35 60 36 59 / 50 20 30 50
LGD 43 60 41 64 / 100 70 20 30
GCD 39 62 39 65 / 90 20 20 50
DLS 49 65 46 71 / 50 50 30 30
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
&&
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
91/91/91
AREA FORECAST DISCUSSION
NWS PORTLAND
215 PM PDT MON MAY 11 2015
.SYNOPSIS...AN UPPER LOW CENTERED WEST OF NEWPORT EARLY THIS
AFTERNOON WILL CONTINUE TO SLOWLY DRIFT SOUTH...THEN MOVE INLAND
INTO SOUTHERN OREGON TONIGHT AND TUESDAY. MOIST SOUTH FLOW ALOFT WILL
RESULT IN UNSETTLED CONDITIONS FOR THE NEXT COUPLE OF DAYS. A BAND OF
STEADIER RAIN ALONG THE CASCADES THIS AFTERNOON IS EXPECTED TO
ENHANCE AND PIVOT NORTH TO NORTHWEST THIS EVENING. THE LOW WILL
MOVE INTO EASTERN OREGON AND EASTERN WASHINGTON TUESDAY NIGHT AND
WEDNESDAY AS ANOTHER LOW DROPS SOUTH OFF THE COAST AND SLOWLY MOVES
INTO CALIFORNIA DURING THE LATTER PART OF THE WEEK AND NEXT WEEKEND.
&&
.SHORT TERM...TONIGHT THROUGH THURSDAY...EARLY-AFTERNOON WATER VAPOR
LOOP SHOWS AN UPPER LEVEL LOW CENTERED WEST OF KONP AND SINKING TO
THE S. CONSIDERABLE MOISTURE IN WATER VAPOR FOCUSED OVER THE
CASCADES. ALSO LOOKS LIKE A SHORT-WAVE ROTATING INTO SOUTH-CENTRAL
OREGON...WHICH HAS RESULTED IN THUNDERSTORM ACTIVITY IN SWRN LAKE
COUNTY. KRTX DUAL-POL DOPPLER RADAR SHOWS THE BULK OF THE PRECIP
ECHOES ALONG THE CENTRAL AND NORTH OREGON CASCADES INTO ERN CLARK AND
COWLITZ COUNTIES IN SW WA. 12Z MODEL RUNS AGREE THAT THE UPPER LOW
WILL CONTINUE TO DRIFT SOUTH THIS EVENING...THEN MOVE INLAND OVER NW
CALIFORNIA BY 12Z TUE. MODELS ALSO SUGGEST THAT PRECIP WILL BECOME
MORE ENHANCED LATE THIS AFTERNOON DUE TO SE-S MID-LEVEL FLOW.
HOWEVER...MODELS DO NOT SEEM TO AGREE ON QPF. GFS SHOW MUCH MORE
RAINFALL TONIGHT THAN THE NAM OR ECMWF. THE NAM PIVOTS THE DEVELPING
DEFORMATION BAND FURTHER N THAN THE GLOBAL MODELS. THE 19Z HRRR RUN
HAS THE DEFORMATION BAND DEVELOPING A FEW HOURS LATER THAN THE
EARLIER MORNING RUNS INDICATED...AND SETTLING OVER SRN WA DOWN TO
ABOUT A KTKM-KSLE-MT. HOOD LINE BY 07Z TUE. HIGH CONFIDENCE IN
WETTING RAIN AMOUNTS...ONE-QUARTER INCH OR GREATER...ACROSS PORTIONS
OF THE CWA TONIGHT AND TUE MORNING. LOWER CONFIDENCE ON EXACT
LOCATION OF THE DEFORMATION BAND.
CONVECTIVE CHANCES TODAY DO NOT LOOK ALL THAT IMPRESSIVE. NAM
SOUNDINGS FOR KPDX SHOW AN ISOTHERMAL LAYER THIS AFERNOON BETWEEN 850
AND 700 MB. MODEL SOUNDING FOR A POINT IN THE CASCADES HAS THE SAME
GENERAL PROFILE...BUT DOES HAVE AN LI NEAR 0C THIS AFTERNOON.
INCREASED POPS IN THE 00-06Z TUE TIME FRAME...ESPECIALLY IN THE
CASCADES AND NORTHERN ZONES. THE DEFORMATION ZONE PERSISTS TUE
MORNING. THE NAM ROTATES IT ACROSS SW WA TO THE N OREGON COAST BY 18Z
TUE...SIMILAR TO THE ECMWF. IT FINALLY BREAKS UP TUE AFTERNOON. THE
MODELS SHOW A DECENT AMOUNT OF CYCLONIC LOW LEVEL ONSHORE FLOW
DEVELOPING BELOW THIS BAND AS WELL. CASCADE MODEL SOUNDINGS SUGGEST A
LIT MORE SUPPORT FOR CONVECTION TUE AFTERNOON. NAM SOUNDING GIVES
200-250 J/KG CAPE 00Z WED...WHILE THE GFS HAS NEAR-ZERO LI VALUES. .
THE REMAINS OF THE UPPER LOW LIFT OUT INTO SE WASHINGTON TUE NIGHT
AND INTO NE WA BY WED AFTERNOON. ANY REMAINING DEFORMATION WILL
LINGER OVER THE S WA CASCADES WED MORNING AND HAVE THE HIGHEST POPS
THERE. DECIDED TO INCLUDE A MENTION OF THUNDERSTORMS FOR THE CENTRAL
AND N OREGON CASCADES BEGINNING WED AFTERNOON. MODEL SOUNDINGS SHOW A
DEFINITE CAP AROUND 700 MB WED MORNING...BUT BY 21Z THE CAP IS GONE
WITH CAPE OVER 100 J/KG. AT 00Z THU MODEL CAPE HAS INCREASED TO
NEARLY 300 J/KG WITH LI -1C. THINK THE S WA CASCADES WILL HAVE TOO
MUCH CLOUD COVER AS THE DEFORMATION BAND SLOWLY DRIFTS N. MUCH MORE
IMPRESSIVE CONVECTIVE ENVIRONMENT POSSIBLE THU. PRIMARY UPPER LOW
SETTLES OFF THE N CALIFORNIA COAST THU AFTERNOON...WHICH SETS UP
UNSTABLE SE-S FLOW OVER THE FORECAST AREA. NAM SOUNDING NEAR SANTIAM
PASS HAS NEARLY 550 J/KG CAPE WITH AN LI OF -2C 00Z FRI. GFS EVEN
MORE IMPRESSIVE WITH CONVECTIVE PARAMETERS THU. WEISHAAR
.LONG TERM...THURSDAY NIGHT THROUGH SUNDAY...BY THURSDAY NIGHT A
BROAD UPPER LOW PRESSURE WILL CONTINUE A GENERAL TRACK SOUTHWARD
ALONG THE CALIFORNIA COAST. MODEL GUIDANCE THIS AFTERNOON IS COMING
INTO GOOD AGREEMENT WITH THE GENERAL PATTERN AND EXPECT SHOWERS
LINGERING THURSDAY NIGHT AND ALSO ON FRIDAY...WITH THE BEST CHANCES
TOWARDS THE CASCADES. MIGHT ALSO BE ENOUGH INSTABILITY TO GET A FEW
THUNDERSTORMS NEAR THE CASCADES FROM MT HOOD SOUTHWARD ON FRIDAY.
THIS UPPER LOW CONTINUES EASTWARD WITH THE NEXT UPPER LOW PRESSURE
SYSTEM MOVING TOWARDS THE REGION OVER THE WEEKEND...MAINTAINING
ONSHORE FLOW ALOFT AND THE POTENTIAL FOR CONTINUING SHOWERS THIS
WEEKEND. OVERALL...NOT MUCH CHANGE TO THE OVERALL PATTERN THROUGH
THE EXTENDED PERIOD WITH TEMPERATURES NEAR SEASONAL NORMS AND SHOWER
CHANCES CONTINUING. CULLEN
&&
.AVIATION...CIGS HAVE LIFTED TO PRIMARILY VFR. SHOWERS ARE STAYING
NORTH OF TAF SITES...WHICH IS HELPING KEEP CIGS VFR. MODELS
SUGGEST THAT THE BAND OF RAIN TO THE NORTH WILL MIGRATE
SOUTHWARD...REACHING NORTHERN TAF SITES AROUND 04Z. AT THIS
TIME CIGS SHOULD DROP TO MVFR AT NORTHERN WILLAMETTE VALLEY TAF
SITES AND KAST. VIS MAY DROP TO MVFR WITH HEAVIER SHOWERS. THIS
BAND OF RAIN SHOULD REMAIN NORTH OF KSLE OVERNIGHT...BUT MODELS
STILL SUGGEST CIGS AT KSLE AND KEUG WILL DROP TO MVFR AROUND
04Z...THOUGH CONFIDENCE IS LOWER. KONP MAY STAY VFR LONGER
OVERNIGHT WITH CONTINUED OFFSHORE FLOW UNTIL RAIN MOVES IN AROUND
09-12Z...WHICH WILL CAUSE CIGS AND POSSIBLY VIS TO DROP TO MVFR.
CIGS ACROSS THE AREA EXPECTED TO REMAIN MVFR THROUGH TUESDAY
MORNING.
KPDX AND APPROACHES...VFR CONDITIONS TO CONTINUE THIS AFTERNOON
UNTIL AROUND 12/04Z WHEN MODERATE RAIN MOVES OVER TERMINAL. CIGS
TO REMAIN MVFR THROUGH TUESDAY MORNING. VIS MAY DROP TO MVFR
OCCASIONALLY WITH HEAVIER SHOWERS. -MCCOY
&&
.MARINE...HIGH PRESSURE OVER THE NE PACIFIC IS KEEPING CONDITIONS
FAIRLY BENIGN. SEAS SHOULD REMAIN AROUND 5 TO 7 FT THROUGH
TUESDAY WITH NORTHWESTERLY WINDS STAYING BELOW 20 KT. A WEAK LOW
PRESSURE SYSTEM MOVES THROUGH ON WEDNESDAY...BUILDING SEAS TO
AROUND 8 FT...BUT WINDS EXPECTED TO REMAIN BELOW 20 KT. SEAS FALL
BACK DOWN TO 5 TO 6 FT BY THE END OF THIS WEEK WITH THE RETURN OF
NORTHWESTERLY WINDS AS HIGH PRESSURE BUILDS BACK OVER THE WATERS.
-MCCOY
&&
.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...UPDATED
NWS MEDFORD OR
1058 PM PDT SUN MAY 10 2015
UPDATED MARINE AND AVIATION SECTIONS
.DISCUSSION...SHOWERS AND ISOLATED THUNDERSTORMS DEVELOPED LATE
THIS AFTERNOON ALONG A COLD FRONT AND AN AXIS OF INSTABILITY FROM
SOUTHERN SISKIYOU COUNTY NORTHEASTWARD TO KLAMATH AND NORTHWEST
LAKE COUNTIES. THE COLD FRONT IS CURRENTLY SHIFTING TO THE EAST OF
THE CASCADES AND WILL EXIT THE CWA OVERNIGHT INTO MONDAY MORNING.
OVERALL, EXPECT SHOWERS TO DECREASE IN COVERAGE ACROSS THE EAST
SIDE AS THE EVENING PROGRESSES, BUT STILL EXPECT ISOLATED SHOWERS
TO LINGER PAST MIDNIGHT. WEST OF THE CASCADES, THE REST OF THIS
EVENING SHOULD BE MAINLY DRY ASIDE FROM ISOLATED SHOWERS ALONG THE
IMMEDIATE COAST. AN UPPER LOW APPROACHING FROM THE PACIFIC WILL
WILL BRING MORE WIDESPREAD SHOWERS TO WEST SIDE AREAS ON MONDAY
WITH ISOLATED THUNDERSTORMS AGAIN FROM THE CASCADES TO THE EAST
SIDE. MONDAY WILL BE MUCH COOLER. MANY INLAND AREAS WILL HAVE
HIGH TEMPERATURES 15 TO 20 DEGREES LOWER THAN THEY WERE TODAY.
SPILDE
&&
.AVIATION...FOR THE 11/06Z TAF CYCLE...EAST OF THE CASCADES...MVFR
TO VFR WITH TERRAIN PARTIALLY OBSCURED AND ISOLATED TO SCATTERED
SHOWERS OVERNIGHT INTO MONDAY MORNING. FROM THE CASCADES
WESTWARD...EXPECT AREAS OF MVFR CIGS WITH TERRAIN
OBSCURED...ESPECIALLY FROM THE UMPQUA DIVIDE NORTH AND WEST. VFR
WILL PREVAIL SOUTH OF THE UMPQUA DIVIDE. AN UPPER LOW WILL MOVE INTO
THE AREA MONDAY WITH MORE NUMEROUS SHOWERS. EXPECT A MIX OF VFR/MVFR
WITH THE LOWER CONDITIONS MOST LIKELY IN HEAVIER SHOWERS. ISOLATED
THUNDERSTORMS ARE POSSIBLE ALONG AND EAST OF THE CASCADES. SPILDE
&&
.MARINE...UPDATED 1040 PM PDT SUNDAY, MAY 10, 2015...NORTH WINDS
WILL INCREASE THROUGH EARLY MONDAY RESULTING IN STEEP
SEAS FOR MOST OF THE WATERS BEYOND 10 MILES OF THE COAST AND INNER
WATERS SOUTH OF PORT ORFORD. SMALL CRAFT ADVISORY CONDITIONS ARE
EXPECTED TO LINGER THROUGH MONDAY NIGHT. SHOWERS ARE EXPECTED
MONDAY EVENING THROUGH WEDNESDAY. WINDS AND SEAS WILL DIMINISH ON
TUESDAY AND ARE LIKELY REMAIN BELOW ADVISORY LEVELS THROUGH
THURSDAY. -SCHAAF/SPILDE
&&
.PREV DISCUSSION... /ISSUED 226 PM PDT SUN MAY 10 2015/
SHORT TERM...CURRENT VISIBLE IMAGE SHOWS CUMULUS ALREADY STARTING
TO BUILD UP ALONG THE CASCADES AND FROM THE SCOTT VALLEY TO THE
TRINITY ALPS AND AND SISKIYOUS IN NORTHERN CAL AND ARE MOVING
NORTHEAST. THE PAST SEVERAL RUNS OF THE HRRR MODEL (WHICH IS
UPDATED HOURLY) CONTINUES TO SHOW SOME CONVECTIVE SHOWERS IN THE
ABOVE MENTION AREAS IN ADDITION TO SOUTH THROUGH EASTERN JACKSON
COUNTY AND NORTHERN KLAMATH COUNTY. THE MODELS SUGGEST THERE`S
ENOUGH INSTABILITY FOR ISOLATED THUNDERSTORMS LATE THIS AFTERNOON
INTO THIS EVENING. THE 700 MB WINDS ARE FROM THE SOUTHWEST, SO
SHOWERS AND ISOLATED STORMS THAT DEVELOP WILL GENERALLY MOVE
NORTHEAST. ISOLATED STORMS WILL END THIS EVENING AS WE LOSE
DAYTIME HEATING, BUT INSTABILITY SHOWERS WILL CONTINUE OVERNIGHT
AS THE UPPER TROUGH CURRENTLY NEAR 45N/130W DIGS SOUTH TOWARDS THE
OREGON COAST.
THE UPPER TROUGH WILL EVOLVE INTO AN UPPER LOW AND THIS WILL BE
RESPONSIBLE FOR BRINGING MUCH COOLER TEMPERATURES...SCATTERED
SHOWERS JUST ABOUT ANYWHERE IN THE FORECAST AREA MONDAY AND TUESDAY.
IN ADDITION, ISOLATED THUNDERSTORMS ARE POSSIBLE ALONG AND EAST OF
THE CASCADES BOTH MONDAY AND TUESDAY AFTERNOON AND EARLY EVENING.
THE UPPER TROUGH WILL DIG SOUTH AND BECOME AND UPPER LOW MONDAY...
REACH THE OREGON COAST MONDAY AFTERNOON, THEN MOVE OVER THE AREA
MONDAY NIGHT INTO TUESDAY. THE MODELS HAVE COME INTO BETTER AGREEMENT
WITH THE PLACEMENT OF THE UPPER LOW WHICH YIELDS HIGHER CONFIDENCE
WE`LL BE COOL AND WET FOR THE START OF NEXT WEEK. THE MODELS ALSO
SHOW THE GREATEST INSTABILITY ALONG AND EAST OF THE CASCADES AND
PLENTY OF SHORTWAVES WILL MOVE OUT AHEAD OF THE UPPER LOW MONDAY
PROVIDING THE TRIGGER FOR ISOLATED STORMS TO FIRE UP.
THE UPPER LOW WILL MOVE OVERHEAD ON TUESDAY BRINGING COLD AIR ALOFT
WITH 500 MB TEMPERATURES BETWEEN -25 AND -28C. SHOWERS WILL OCCUR
JUST ABOUT ANYWHERE TUESDAY WITH SOME MODERATE TO HEAVY IN THE
AFTERNOON AS WE REACH MAX HEATING. SNOW LEVELS TUESDAY ARE EXPECTED
TO BE AROUND 5000 FEET, BUT WILL TEMPORARILY LOWER IN HEAVIER
SHOWERS. RIGHT NOW, WERE ONLY EXPECTING SNOW TO ACCUMULATE OVER THE
HIGHER TERRAIN ALONG AND EAST OF THE CASCADES. ISOLATED
THUNDERSTORMS REMAIN A CONCERN TUESDAY AFTERNOON ALONG AND EAST OF
THE CASCADES.
SHOWERS ARE EXPECTED TO GRADUALLY DECREASE TUESDAY NIGHT AS THE
UPPER LOW WEAKENS AND MOVES NORTH. HOWEVER THE NAM SHOW ANOTHER
SHORTWAVE ON THE HEALS OF THE UPPER TROUGH AND WE COULD SEE SHOWERS
INCREASE AGAIN EARLY WEDNESDAY MORNING. THE GFS IS SLOWER WITH THE
NEXT SHORTWAVE AND EC IS ALSO SLOWER AND WEAKER. EITHER ONE OF THESE
SOLUTIONS WILL RESULT IN A COOL AND UNSETTLED PATTERN ON WEDNESDAY.
-PETRUCELLI
LONG TERM...THURSDAY THROUGH SUNDAY...AN ACTIVE SHOWERY PATTERN
WITH A SLIGHT OF THUNDERSTORMS CONTINUES THROUGH THE EXTENDED
PERIOD AS AN UPPER LOW SHIFTS SOUTH AND THEN MOVES INLAND. ON
THURSDAY A STRONG UPPER LOW IS FORECAST TO SHIFT SOUTH OFF THE
CALIFORNIA COAST. SOUTHERLY MOISTURE IS FORECAST TO MOVE INTO THE
AREA AHEAD OF THIS LOW AND BRING SHOWERS ALONG WITH A SLIGHT
CHANCE OF THUNDERSTORMS ACROSS THE AREA. GIVEN THE SOUTH TO
SOUTHEAST FLOW ALOFT, HAVE EXTENDED THE SLIGHT RISK FOR
THUNDERSTORMS FURTHER WEST TO INCLUDE SOME WESTERN VALLEYS AS WELL
AS FROM THE CASCADES EAST. ON FRIDAY...THE UPPER LOW IS FORECAST
TO MOVE INTO SOUTHERN AND CENTRAL CALIFORNIA. MODELS CONTINUE TO
SHOW MOISTURE MOVING AROUND THE LOW INTO THE AREA ON FRIDAY WITH
INSTABILITY BRINGING A MIX OF SHOWERS AND POSSIBLE ISOLATED
THUNDERSTORMS. ON FRIDAY, THE BEST CHANCE FOR ANY THUNDERSTORMS IS
EXPECTED FROM THE CASCADES EASTWARD ON FRIDAY BUT MAY EXTEND
FURTHER WEST ALONG THE WESTERN SLOPES OF THE CASCADES AND INTO
CENTRAL AND WESTERN SISKIYOU COUNTY. ON SATURDAY...AS THIS UPPER
LOW MOVES INLAND TO THE EAST- NORTHEAST...EXPECT SOME CONTINUED
SHOWER ACTIVITY OVER THE AREA. THE SLIGHT CHANCE OF THUNDERSTORMS
IS EXPECTED ONLY FOR FAR EASTERN ZONES IN LAKE AND MODOC COUNTIES.
LATE SATURDAY INTO SUNDAY...THE AREA MAY BE LOCATED BETWEEN THE
UPPER LOW WELL TO THE EAST AND A WEAK UPPER LOW OFF THE OREGON
COAST. DEPENDING ON THE POSITION OF THESE LOWS, MAY SEE SOME
CONTINUED SHOWERS OVER THE AREA. ALSO IF THE UPPER LOW OFF THE
COAST OF OREGON TRENDS STRONGER, MAY SEE ANOTHER CHANCE FOR
THUNDERSTORMS IN THE AREA ON SUNDAY. /CC
FIRE WEATHER...UPDATED 100 PM PDT SUNDAY, MAY 10, 2015...A WEAK
COLD FRONT WILL PERSIST OVER THE AREA THIS AFTERNOON AND EVENING
ALLOWING SHOWERS AND ISOLATED THUNDERSTORMS TO DEVELOP FROM ABOUT
THE SHASTA AND SCOTT VALLEYS NORTHWARD TO THE SISKIYOUS AND INTO THE
CASCADES THIS AFTERNOON. STORMS ARE ALSO POSSIBLE ALONG THE WESTERN
SLOPES OF THE CASCADES AND INTO PORTIONS OF THE ROGUE VALLEY LATE
THIS AFTERNOON. THEN THIS EVENING...EXPECT ISOLATED THUNDERSTORMS
FROM THE CASCADES EASTWARD. MID-LEVEL SOUTHWEST FLOW WITH NORTHWEST
FLOW IN THE LOWER LEVELS WILL CAUSE WINDS AND MOISTURE TO CONVERGE
IN THESE AREAS AND MODELS CONTINUE TO SHOW INSTABILITY WITH THE
POTENTIAL FOR ISOLATED THUNDERSTORMS. STORMS SHOULD GENERALLY
PRODUCE RAINFALL, THOUGH AMOUNTS ARE LIKELY TO BE LIGHT TO MODERATE
AT 0.10" TO 0.25" OR LESS. STORMS ARE EXPECTED TO MOVE FROM
SOUTHWEST TO NORTHEAST AT 10-20 KNOTS. THE STORMS WILL CAPABLE OF
GUSTY OUTFLOW WINDS OF 25 TO 35 MPH AND SMALL HAIL. GUSTY WEST TO
SOUTHWEST WINDS ARE EXPECTED AHEAD OF THE FRONT OVER THE EAST SIDE
THIS AFTERNOON, WITH GUSTY NORTHWEST WINDS BEHIND IT ON THE WEST
SIDE.
SCATTERED SHOWERS ACROSS THE AREA TONIGHT WILL INCREASE IN
COVERAGE AND INTENSITY MONDAY MORNING THROUGH MONDAY EVENING AS AN
UPPER LOW MOVES INTO THE COAST. ISOLATED THUNDERSTORMS MIXED WITH
SHOWERS ARE EXPECTED ON THE EAST SIDE MONDAY AFTERNOON AND
EVENING, PRIMARILY FOR EASTERN SISKIYOU, MODOC, EASTERN KLAMATH
AND LAKE COUNTIES. THEN SHOWERS AND ISOLATED THUNDERSTORMS ARE
LIKELY OVER MUCH OF THE AREA ON TUESDAY AS THE UPPER LEVEL LOW
MOVES OVERHEAD. /CC
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
CA...NONE.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL
11 PM PDT MONDAY FOR PZZ350-356-370-376.
SMALL CRAFT ADVISORY FOR WINDS FROM 2 AM TO 11 PM PDT MONDAY FOR
PZZ376.
$$
MAS/MAP/CC/TRW/BMS
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
759 AM EDT MON MAY 11 2015
.SYNOPSIS...
AN ANOMALOUS UPPER LEVEL RIDGE WILL SHIFT OFF THE EAST COAST
TODAY. A SHARP COLD FRONT WILL CROSS CENTRAL PA EARLY
TUESDAY...FOLLOWED BY A LARGE HIGH PRESSURE SYSTEM BUILDING
SOUTHEAST INTO PA FOR THE SECOND PART OF THE WORK WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
REGIONAL RADAR LOOP SHOWING SCT CONVECTION WORKING INTO THE NW
MTNS AT 09Z IN ASSOC WITH A WEAK SHORTWAVE RIDING ALONG NW
PERIPHERY OF UPPER RIDGE. HRRR SUPPORTS A CONTINUING CHC OF A
SHRA ACROSS THE NW MTNS THRU ARND 12Z...THEN A DIMINISHING CHC OF
PRECIP AFTER 12Z...AS SHOWERS RUN INTO A MORE UNFAVORABLE
ENVIRONMENT BENEATH UPPER RIDGE OVR CENTRAL PA. ACROSS EASTERN
PA...MARINE STRATUS DECK...WHICH COVERS AREAS EAST OF THE SUSQ
RIVER AT 0930Z...SHOULD MIX OUT TO SCT-BKN CU BY LATE AM.
AS RIDGE AXIS SLIDES EAST...PLUME OF HIGHER PWATS WILL OVERSPREAD
THE REGION TODAY. THE INCREASED HUMIDITY/INSTABILITY...COMBINED
WITH PASSAGE OF A WEAK MID LVL VORT MAX...SHOULD SUPPORT SCT PM
TSRA...ESP ACROSS THE CENTRAL MTNS. AN EXAMINATION OF MDL
SOUNDINGS SHOWS MODERATE CAPE OF ARND 1500 J/KG AND WEAK
SHEAR...IMPLYING MOSTLY PULSE TYPE CONVECTION W/LITTLE RISK OF
ORGANIZED SVR WX. MDL 8H TEMPS SUPPORT HIGHS IN THE L/M80S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
BULK OF MDL DATA SUPPORTS A LULL IN CONVECTIVE ACTIVITY THIS
EVENING BTWN SCT DIURNALLY-DRIVEN ACTIVITY LATE THIS AFTN AND
ARRIVAL OF SHARP COLD FRONT LATE TONIGHT. ALL MDL DATA TRACKS COLD
FRONT THRU MOST OF CENTRAL PA BTWN 06Z-12Z TUESDAY...LIKELY
SPARING THE AREA SVR WX. IN ADDITION...PARENT SHORTWAVE AND BULK
OF LG SCALE FORCING IS PROGGED TO PASS WEST OF PA THRU THE GRT
LKS. HAVE PLACED THE HIGHEST /LKLY/ POPS ACROSS THE NW MTNS
TONIGHT AND THE LOWEST CHC OF RAIN ACROSS THE SE
COUNTIES...FURTHEST FROM UPPER LVL SUPPORT. TONIGHT WILL LIKELY BE
THE WARMEST NIGHT OF OUR RECENT STRING OF WARM NIGHTS...DUE TO
SURGING LOW LVL MOISTURE AND INCREASING CLOUD COVER.
TUESDAY WILL BE A DRY AND WINDY DAY FOR MOST OF CENTRAL PA BEHIND
COLD FRONT...AS STRENGTHENING PARENT LOW PASSES NORTH OF PA.
BUFKIT SOUNDINGS SUPPORT WGUSTS TO ARND 30KTS. AN ADDITIONAL
-SHRA IS POSSIBLE IN A FEW SPOTS TUES AFTN WITH PASSAGE OF UPPER
LVL TROF AXIS. HOWEVER...PTSUNNY AND DRY WX EXPECTED FOR MOST.
ENS MEAN 8H TEMPS STILL INDICATE TEMPS ABOVE NORMAL WITH MAX
READINGS LIKELY RANGING FROM THE U60S OVER THE NW MTNS...TO THE
L80S ACROSS THE LOWER SUSQ VALLEY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
UPPER TROF AND COOL TEMPS ALOFT WILL REMAIN OVR PA
WED...LKLY RESULTING IN A GOOD DEAL OF AFTN CU/STRATOCU...ESP OVR
THE MTNS. 8H TEMPS SUPPORT HIGHS ONLY IN THE 50S TO L60S. THURSDAY
MORNING COULD BE QUITE CHILLY...AS SFC HIGH BUILDS OVER THE AREA.
MAY HAVE TO CONTEND W/POSSIBLE FROST OVR THE NW MTNS THOSE
MORNINGS WITH MINS LKLY IN THE 30S. GROWING SEASON STARTS MAY 11
OVER PARTS OF THE ALLEGHENY MTNS. CONFIDENCE IN NEAR-FREEZING
TEMPS IS HIGHEST IN MCKEAN/POTTER AND ELK BUT THE GROWING SEASON
DOES NOT BEGIN IN THESE COUNTIES UNTIL MAY 21.
BY LATE NEXT WEEK...ALL MED RANGE GUIDANCE SHOWS UPPER LVL RIDGE
REBUILDING ACROSS THE GRT LKS. HAVE INTRODUCED THE CHC OF SHOWERS
LATE FRIDAY/SATURDAY...WHEN MDLS SHOW A SHORTWAVE CRESTING RIDGE
AND DIVING SE TOWARD PA.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AN UPPER LEVEL RIDGE WILL SHIFT OFF THE EAST COAST TODAY. A SHARP
COLD FRONT WILL CROSS CENTRAL PA EARLY TUESDAY...FOLLOWED BY A
LARGE HIGH PRESSURE SYSTEM FOR MIDWEEK.
UPPER LEVEL RIDGE BEGINNING TO GRADUALLY BREAK DOWN OVER THE
REGION TODAY. VFR CONDITIONS IN PLACE FOR MUCH OF CWA...WITH
MARINE LAYER STRATUS/FOG DECK IMPACTING THE SUSQ VALLEY FROM KIPT
TO KMDT-KLNS WITH MVFR CIGS. THIS SHOULD MIX OUT THROUGH THE MID
MORNING...LINGERING LONGEST AT KMDT-KLNS.
BY AFTERNOON...LOW LEVEL MOISTURE WILL BE INCREASING AS A WEAK MID
LEVEL SHORTWAVE SLIDES THROUGH. THIS WILL BE ENOUGH TO INITIATE
SCT SHOWERS / ISO TSTMS ACROSS THE WEST...WITH ONLY ISOLATED
CONVECTION POSS IN CENTRAL/EASTERN SECTIONS.
AFTER A LULL DURING THE EVENING...SHARP COLD FRONT MOVES THROUGH
OVERNIGHT KICKING OFF ANOTHER ROUND OF SCT/NUM SHOWERS AND ISO
TSTMS...MAINLY FOR WESTERN AND CENTRAL MTNS. TIMING OF FRONT COULD
ALLOW THE MARINE LAYER STRATUS TO RETURN IN THE LOWER SUSQ. AND
BEHIND THE FRONT MVFR CIGS WILL SLIDE INTO KBFD-KJST AS SW/W WINDS
BECOME BREEZY.
OUTLOOK...
TUE...MORNING LOW CLOUDS AND FOG POSSIBLE...THEN BREEZY AND LESS
HUMID WITH AREAS OF MVFR CIGS ACROSS THE NRN AND WRN MTNS.
WED-THU...VFR.
FRI...MVFR WITH SCT SHRA.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD/MARTIN
AVIATION...RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
613 AM EDT MON MAY 11 2015
.SYNOPSIS...
AN ANOMALOUS UPPER LEVEL RIDGE WILL SHIFT OFF THE EAST COAST
TODAY. A SHARP COLD FRONT WILL CROSS CENTRAL PA EARLY
TUESDAY...FOLLOWED BY A LARGE HIGH PRESSURE SYSTEM BUILDING
SOUTHEAST INTO PA FOR THE SECOND PART OF THE WORK WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
REGIONAL RADAR LOOP SHOWING SCT CONVECTION WORKING INTO THE NW
MTNS AT 09Z IN ASSOC WITH A WEAK SHORTWAVE RIDING ALONG NW
PERIPHERY OF UPPER RIDGE. HRRR SUPPORTS A CONTINUING CHC OF A
SHRA ACROSS THE NW MTNS THRU ARND 12Z...THEN A DIMINISHING CHC OF
PRECIP AFTER 12Z...AS SHOWERS RUN INTO A MORE UNFAVORABLE
ENVIRONMENT BENEATH UPPER RIDGE OVR CENTRAL PA. ACROSS EASTERN
PA...MARINE STRATUS DECK...WHICH COVERS AREAS EAST OF THE SUSQ
RIVER AT 0930Z...SHOULD MIX OUT TO SCT-BKN CU BY LATE AM.
AS RIDGE AXIS SLIDES EAST...PLUME OF HIGHER PWATS WILL OVERSPREAD
THE REGION TODAY. THE INCREASED HUMIDITY/INSTABILITY...COMBINED
WITH PASSAGE OF A WEAK MID LVL VORT MAX...SHOULD SUPPORT SCT PM
TSRA...ESP ACROSS THE CENTRAL MTNS. AN EXAMINATION OF MDL
SOUNDINGS SHOWS MODERATE CAPE OF ARND 1500 J/KG AND WEAK
SHEAR...IMPLYING MOSTLY PULSE TYPE CONVECTION W/LITTLE RISK OF
ORGANIZED SVR WX. MDL 8H TEMPS SUPPORT HIGHS IN THE L/M80S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
BULK OF MDL DATA SUPPORTS A LULL IN CONVECTIVE ACTIVITY THIS
EVENING BTWN SCT DIURNALLY-DRIVEN ACTIVITY LATE THIS AFTN AND
ARRIVAL OF SHARP COLD FRONT LATE TONIGHT. ALL MDL DATA TRACKS COLD
FRONT THRU MOST OF CENTRAL PA BTWN 06Z-12Z TUESDAY...LIKELY
SPARING THE AREA SVR WX. IN ADDITION...PARENT SHORTWAVE AND BULK
OF LG SCALE FORCING IS PROGGED TO PASS WEST OF PA THRU THE GRT
LKS. HAVE PLACED THE HIGHEST /LKLY/ POPS ACROSS THE NW MTNS
TONIGHT AND THE LOWEST CHC OF RAIN ACROSS THE SE
COUNTIES...FURTHEST FROM UPPER LVL SUPPORT. TONIGHT WILL LIKELY BE
THE WARMEST NIGHT OF OUR RECENT STRING OF WARM NIGHTS...DUE TO
SURGING LOW LVL MOISTURE AND INCREASING CLOUD COVER.
TUESDAY WILL BE A DRY AND WINDY DAY FOR MOST OF CENTRAL PA BEHIND
COLD FRONT...AS STRENGTHENING PARENT LOW PASSES NORTH OF PA.
BUFKIT SOUNDINGS SUPPORT WGUSTS TO ARND 30KTS. AN ADDITIONAL
-SHRA IS POSSIBLE IN A FEW SPOTS TUES AFTN WITH PASSAGE OF UPPER
LVL TROF AXIS. HOWEVER...PTSUNNY AND DRY WX EXPECTED FOR MOST.
ENS MEAN 8H TEMPS STILL INDICATE TEMPS ABOVE NORMAL WITH MAX
READINGS LIKELY RANGING FROM THE U60S OVER THE NW MTNS...TO THE
L80S ACROSS THE LOWER SUSQ VALLEY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
UPPER TROF AND COOL TEMPS ALOFT WILL REMAIN OVR PA
WED...LKLY RESULTING IN A GOOD DEAL OF AFTN CU/STRATOCU...ESP OVR
THE MTNS. 8H TEMPS SUPPORT HIGHS ONLY IN THE 50S TO L60S. THURSDAY
MORNING COULD BE QUITE CHILLY...AS SFC HIGH BUILDS OVER THE AREA.
MAY HAVE TO CONTEND W/POSSIBLE FROST OVR THE NW MTNS THOSE
MORNINGS WITH MINS LKLY IN THE 30S. GROWING SEASON STARTS MAY 11
OVER PARTS OF THE ALLEGHENY MTNS. CONFIDENCE IN NEAR-FREEZING
TEMPS IS HIGHEST IN MCKEAN/POTTER AND ELK BUT THE GROWING SEASON
DOES NOT BEGIN IN THESE COUNTIES UNTIL MAY 21.
BY LATE NEXT WEEK...ALL MED RANGE GUIDANCE SHOWS UPPER LVL RIDGE
REBUILDING ACROSS THE GRT LKS. HAVE INTRODUCED THE CHC OF SHOWERS
LATE FRIDAY/SATURDAY...WHEN MDLS SHOW A SHORTWAVE CRESTING RIDGE
AND DIVING SE TOWARD PA.
&&
.AVIATION /09Z MONDAY THROUGH FRIDAY/...
UPPER RIDGE REMAINS OVER THE REGION. WEAK SHORTWAVE SLIDING OVER
LAKE ERIE MAY KICK OFF ISOLATED SHOWERS/TSRA WEST OF KBFD THROUGH
10Z. BUT MAIN FOCUS OVERNIGHT WILL BE THE REDEVELOPMENT OF
STRATUS/FOG DECK OVER SE PORTIONS OF PA. SREF CIG PROBS AND MDL
SOUNDINGS SUGGEST THE LOW CLOUDS COULD REACH ALL THE WAY TO THE
CENTRAL MTNS...THOUGH BEST CHANCES FOR EXTENDED PERIOD OF
REDUCTIONS WILL BE AT KMDT-KLNS - FROM 08Z THROUGH THE MID
MORNING.
WE/LL SEE A BETTER CHANCE FOR SHRA/TSRA DURING THE DAY ON MON AS
RIDGE BEGINS TO BREAKS DOWN /AND REMNANTS OF ANA SLIDE TOWARD THE
MID ATLANTIC COAST/ WHILE LOW-LEVEL MOISTURE CONTINUES TO INCREASE.
SCT TO NUM SHOWERS WILL DEVELOP IN THE AFTERNOON AND CONTINUE INTO
THE EVENING HOURS MAINLY ACROSS THE NW HALF OF CWA...ALONG WITH
ISOLATED LATE DAY TSTMS.
OUTLOOK...
MON...SCT-NUMEROUS AFTERNOON AND EARLY NIGHTTIME TSRA IMPACTS
POSSIBLE. PATCHY MVFR TO IFR IN FOG LATE.
TUE...MORNING LOW CLOUDS AND FOG POSSIBLE...THEN BREEZY AND LESS
HUMID WITH AREAS OF MVFR CIGS ACROSS THE NRN AND WRN MTNS.
WED-THU...VFR.
FRI...MVFR WITH SCT SHRA.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD/MARTIN
AVIATION...RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
248 AM EDT MON MAY 11 2015
.SYNOPSIS...
AN ANOMALOUS UPPER LEVEL RIDGE WILL REMAIN OVER THE NORTHEAST
CONUS THROUGH MONDAY. A SHARP COLD FRONT WILL CROSS THE AREA
EARLY TUESDAY...FOLLOWED BY A LARGE HIGH PRESSURE SYSTEM BUILDING
SOUTHEAST INTO PA FOR THE SECOND PART OF THE WORK WEEK. AFTER A
TASTE OF EARLY SUMMER WEATHER...TEMPERATURES WILL AVERAGE BELOW
NORMAL.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
REGIONAL RADAR LOOP SHOWING SCT CONVECTION WORKING INTO THE NW
MTNS AT 06Z IN ASSOC WITH A WEAK SHORTWAVE RIDING ALONG NW EDGE
OF UPPER RIDGE. HRRR SUPPORTS CHC POPS OF A SHRA/TSRA ACROSS THE
NW MTNS DURING THE PRE-DAWN HOURS...THEN A DIMINISHING CHC OF
PRECIP BY 12Z...AS SHORTWAVE LIFTS NORTH OF THE AREA.
ELSEWHERE...FOCUS EARLY THIS MORNING IN ON MARINE STRATUS DECK
ADVECTING INTO SOUTHEAST PA. LATEST SREF/RAP DATA SUPPORT MCLDY
SKIES BY DAWN EAST OF THE SUSQ RIVER. TEMPS ON TRACK TO BOTTOM
OUT BTWN 60-65F ACROSS THE AREA.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH 6 PM TUESDAY/...
THE REMNANTS OF TS ANA ARE STILL EXPECTED TO PASS FAR ENOUGH
SOUTH OF PA TO NOT DIRECTLY IMPACT THE AREA TODAY. AS RIDGE AXIS
SLIDES EAST...PLUME OF HIGHER PWATS WILL OVERSPREAD THE REGION
TODAY. THE INCREASED HUMIDITY/INSTABILITY SHOULD RESULT IN BETTER
COVERAGE OF TSRA THIS AFTN...ESP ACROSS THE CENTRAL MTNS. AN
EXAMINATION OF MDL SOUNDINGS SHOWS MODERATE CAPE OF ARND 1500 J/KG
AND WEAK SHEAR...IMPLYING MOSTLY PULSE TYPE CONVECTION W/LITTLE
RISK OF ORGANIZED SVR WX. MDL 8H TEMPS SUPPORT HIGHS IN THE
L/M80S.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
EXPECTING SOME SHOWERS AND THUNDERSTORMS FOR MONDAY NIGHT.
HIGHEST POPS TO THE WEST AND NORTH...GIVEN THE TIMING OF
THE COLD FRONT AND THE BEST DYNAMICS TRACK TO THE WEST
AND NORTH.
SOME SHOWERS POSSIBLE STILL ON TUE...MAINLY DURING THE FIRST
PART OF THE DAY...GIVEN TIMING OF THE COLD FRONT.
DAY 3 OUTLOOK HAS NO SEVERE FOR CENTRAL PA. MAKES SENSE...GIVEN
TIMING OF THE FROPA...WEAK HEIGHT FALLS...AND LACK OF SURFACE
CONVERGENCE. REMAINS OF ANA AID IN SHIFTING THE WINDS MORE TO THE
WEST BEFORE THE COLD FRONT GETS INTO THE AREA. WHILE THE UPPER
LVL TROUGH IS RATHER STRONG...IT LAGS THE COLD FRONT.
SOME SHOWERS FOR TUE NIGHT INTO WED ACROSS THE NORTH AND PERHAPS
THE LAURELS...GIVEN THE UPPER LVL LOW AND COLD AIR ALOFT.
THU AND FRI LOOKING DRY...BUT ON THE COOL SIDE. WILL HAVE TO
MONITOR FOR THE NEED FOR FROST AND FREEZE PRODUCTS.
MID SHIFT INSERTED LOW POPS FOR FRIDAY NIGHT INTO SAT. MODELS
STILL SHOW A SHORT WAVE DROPPING SE IN THE NW FLOW. MOISTURE
LIKELY TO BE LIMITED...BUT GIVEN THE DIRECTIONAL SHEAR...SOME
SUPPORT FOR SHOWERS AND PERHAPS A THUNDERSTORM. THUS LEFT THE
SHOWERS IN.
DID NOT CARRY SHOWERS PAST SUNDAY MORNING...AS MODELS SHOW
RIDGING ALOFT. WENT WITH A DRY FCST FOR MONDAY FOR NOW. BEST
WARM ADVECTION IS TO THE WEST.
&&
.AVIATION /07Z MONDAY THROUGH FRIDAY/...
UPPER RIDGE REMAINS OVER THE REGION TONIGHT. SCT SHRA/TSRA WILL
BE CONFINED TO THE FAR WEST/NORTHWEST RTES AS A SHORTWAVE TROF
ROTATES EWD FROM NE OHIO INTO THE FINGERLAKES REGION AND STORMS
AND SHOWERS STREAM OVER THE SLOWLY WEAKENING RIDGE. ANY
CONVECTION THAT DOES GET GOING WILL DIMINISH QUICKLY WITH LOSS OF
HEATING AS THE EVENING CONTINUES. FOCUS THEN SHIFTS BACK TO
OVERNIGHT REDEVELOPMENT OF STRATUS/FOG OVER SE PORTIONS OF PA.
SREF CIG PROBS AND MDL SOUNDINGS SUGGEST THE LOW CLOUDS COULD
REACH ALL THE WAY INTO THE CENTRAL MTNS. BETTER CHC OF SHRA/TSRA
ON MON AS MOISTURE INCREASES REGION WIDE AS THE RIDGE BREAKS
DOWN AND WARMER THAN NORMAL DAYTIME HIGHS.
OUTLOOK...
MON...SCT-NUMEROUS AFTERNOON AND EARLY NIGHTTIME TSRA IMPACTS
POSSIBLE. PATCHY MVFR TO IFR IN FOG LATE.
TUE...MORNING LOW CLOUDS AND FOG POSSIBLE...THEN BREEZY AND LESS
HUMID WITH AREAS OF MVFR CIGS ACROSS THE NRN AND WRN MTNS.
WED-THU...VFR.
FRI...MVFR WITH SCT SHRA.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DEVOIR/MARTIN
NEAR TERM...FITZGERALD
SHORT TERM...DANGELO/FITZGERALD
LONG TERM...MARTIN
AVIATION...RXR
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
152 PM EDT MON MAY 11 2015
.SYNOPSIS...
THE REMNANTS OF ANA WILL CONTINUE TO MOVE NORTHEAST ALONG THE
ATLANTIC COAST TONIGHT. ON TUESDAY...A WEAK COLD FRONT WILL CROSS
OUR AREA BEFORE STRONG HIGH PRESSURE BUILDS IN FROM THE NORTH AND
REMAINS THROUGH THURSDAY. ANOTHER COLD FRONT WILL APPROACH THE REGION
ON FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 145 PM EDT MONDAY...NO SIGNIFICANT CHANGES TO THE FCST WITH
THIS UPDATE. DID TWEAK POPS/SKY/TEMPS A BIT TO BETTER REFLECT
RECENT RADAR/OB TRENDS AS CONVECTION HAS INITIATED ACROSS PORTIONS
OF THE NC HIGH TERRAIN. OTHERWISE...FULL FCST DISCUSSION TO FOLLOW
WITHIN THE HOUR.
PREVIOUS DISCUSSION...
AS OF 310 AM...ISOLATED CONVECTION CONTINUES TO FIRE ALONG A
GRADIENT IN MUCAPE SOUTH OF THE I-85 CORRIDOR THIS MORNING. WILL
CONTINUE TO RETAIN 20 POPS IN THIS AREA THROUGH ABOUT DAYBREAK.
OTHERWISE...ATTENTION TURNS TO THE CONVECTIVE POTENTIAL FOR LATER
TODAY. DEWPOINTS IN THE MID/UPPER 60S ARE EXPECTED TO COMBINE WITH
STEEP LOW LEVEL LAPSE RATES TO YIELD SOME OF THE MORE ROBUST CAPE
VALUES WE/VE SEEN IN RECENT DAYS...WITH A CONSENSUS OF DETERMINISTIC
AND ENSEMBLE GUIDANCE CLEARLY SUPPORTING SBCAPE IN THE 2000-2500
J/KG RANGE THIS AFTERNOON. IN ADDITION...MOISTURE WILL BE MORE
PLENTIFUL THROUGH A DEEP LAYER...WITH PWATS OF AROUND 1.5...OR ABOUT
2 STANDARD DEVS ABOVE CLIMO...EXPECTED ACROSS THE PIEDMONT THIS PM.
WHAT WILL BE LACKING IS AN OBVIOUS SOURCE OF ORGANIZED LIFT.
HOWEVER...IT IS INTERESTING THAT SOME OF THE CONVECTION-ALLOWING
MODELS...AND EVEN THE NAM APPEAR TO BE HIGHLIGHTING A LOW LEVEL
CONVERGENCE AXIS ACROSS EAST TENN AND NORTH GA. THE HRRR AND NSSL
WRF LIGHT THIS AREA UP...SUGGESTING (AT LEAST) NUMEROUS CONVECTIVE
COVERAGE BY EARLY/MID AFTERNOON...WHICH WOULD PUSH INTO OUR AREA
BY MID/LATE AFTERNOON. LIKELY POPS WILL BE CARRIED OVER THE
MTNS...WHERE DIFF HEATING STILL APPEARS TO BE THE BEST BET FOR
INITIATING CONVECTION. HOWEVER...POPS HAVE ALSO BEEN BUMPED TO 50
PERCENT ACROSS MUCH OF THE REMAINDER OF THE WESTERN HALF OF THE
FORECAST AREA. IF THE MESOSCALE MODELS HAVE THE RIGHT IDEA...
THIS WILL BE TOO LOW. WHILE PROFILES ARE GENERALLY MOIST...STEEP
LOW LEVEL LAPSE RATES/A HOT BOUNDARY LAYER SHOULD YIELD
DOWNDRAFT CAPE IN THE 500-1000 J/KG RANGE THIS AFTERNOON...WHICH
COULD COMBINE WITH WEAK SHEAR AND WATER LOADING TO YIELD A WET
MICROBURST THREAT WITH SOME OF THE STRONGER UPDRAFTS. WHILE DEEP
LAYER SHEAR IS WEAK...THERE COULD BE JUST ENOUGH SHEAR OVER COLD
POOL DEPTH TO PROMOTE SOME DEGREE OF LIMITED UPSCALE ORGANIZATION...
WHICH WOULD RESULT IN A MORE ORGANIZED DOWNBURST THREAT.
COVERAGE OF CONVECTION WILL GRADUALLY DIMINISH TONIGHT. A COLD FRONT
WILL APPROACH THE SOUTHERN APPALACHIANS FROM THE TENN VALLEY
OVERNIGHT. HOWEVER...THERE IS A DEFINITIVE MODEL CONSENSUS
SUGGESTING THAT ANY ASSOCIATED CONVECTION WILL BE DIMINISHING AS THE
BOUNDARY NUDGES INTO THE FORECAST AREA TOWARD DAYBREAK. TOKEN SMALL
CHANCE POPS WILL NEVERTHELESS BE RETAINED. TEMPERATURES WILL REMAIN
A SOLID 10 DEGREES ABOVE CLIMO THROUGH THE PERIOD.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
200 PM EDT MONDAY...SHORT TERM LOOKS TO BE RATHER TRANQUIL AS
COLD FRONT SETTLES WELL SOUTH OF THE AREA AS DRY CP HIGH PRESSURE
BUILDS IN FROM THE NW. AN UPPER RIDGE IS FORECAST TO BUILD ACROSS
THE SE U.S. WED THROUGH THU. DEWPOINTS ARE FORECAST TO DROP WELL
INTO THE 40S ON WED WITH ONLY A SLOW RECOVERY ON THU INTO THE 50S AS
THE SURFACE HIGH MOVES TO THE COAST. HENCE...MOSTLY CLEAR CONDITIONS
WILL BE IN THE FORECAST TUE NIGHT THROUGH THURSDAY WITH TEMPS
LOWERING TO NEAR SEASONAL VALUES.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
215 PM EDT MONDAY...THE MEDIUM RANGE WILL BE UNSETTLED AS THE
AXIS OF THE UPPER HIGH INITIALLY MOVES EAST OF THE AREA ALONG THE
COAST. ALSO AS THE SURFACE MOVES INTO THE WESTERN ATLANTIC...RETURN FLOW
WILL TAP INTO GULF MOISTURE. MODEL TIME HEIGHTS INDICATE THAT DEEP
LAYER MOISTURE WILL ADVECT INTO THE WESTERN CAROLINAS AND NE GA
DURING FRIDAY AND REMAIN IN PLACE INTO THE FIRST PART OF NEXT WEEK.
WITH THE PERSISTENT DEEP MOISTURE IN PLACE...MODELS AND ESPECIALLY
THE GFS RESPOND WITH CONSIDERABLE QPF. INSTABILITY IS FORECAST TO BE
ON THE LOW SIDE INITIALLY ON FRI AS PERHAPS IN-SITU CAD DEVELOPS.
MODELS INDICATE THAT INSTABILITY WILL THEN GRADUALLY INCREASE EACH
AFTERNOON FROM SAT THROUGH MON.THE EC SHOWS MORE OF A DIURNAL CYCLE
TO THE QPF OVER THE WEEKEND WHICH LOOKS MORE REASONABLE AND WILL
TREND FROECAST THAT WAY. WILL RAMP UP POPS TO CHANCE FRIDAY
AFTERNOON. GUIDANCE THEN SUGGESTS THAT SOME LIKLEY POPS WILL BE
NEEDED SAT AND SUN AFTERNOONS OVER THE MOUNTAINS. ON
MONDAY...COVERAGE OF SHOWERS AND THUNDERSTORMS MAY BECOME LESS IF UPPER
RIDGE BUILDS BACK OVER THE REGION PER THE GFS. INCREASED CLOUD COVER
WILL KEEP TEMPS IN CHECK INITIALLY WITH A REDUCED DIURNAL RANGE. MAX
TEMPS ARE EXPECTED TO BE BELOW CLIMO FRI...THEN INCREASE TO AROUND
CLIMO SAT AND THEN ABOVE SUN AND MON AS UPPER RIDGE REESTABLISHES
ITSELF.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AT KCLT...PREDOMINATELY VFR THROUGH THE PERIOD WITH THE EXCEPTION OF
POSSIBLE MVFR RESTRICTIONS RESULTING FROM AFTERNOON CONVECTION.
INITIALIZED TAF WITH MODEST SW WINDS UNDER FEW LLV CU AS LAPSE RATES
CONTINUE TO STEEPEN WITH HEATING. FURTHER CU FIELD EXPANSION IS
EXPECTED THROUGH THE AFTERNOON...THUS PREVAIL LLV VFR CIGS AT 20Z
WITH A 4HR TEMPO FOR DEVELOPING AIRMASS TSRA YIELDING VRB 20KT
GUSTS. ALL WX IS REMOVED NLT 01Z WITH MID LEVEL CLOUDS PREVAILING
UNDER BKN HIGH LEVEL CIGS WITH LIGHT WINDS THROUGH THE OVERNIGHT.
WINDS WILL INCREASE LATE IN THE PERIOD AS FRONTAL AXIS APPROACHES
FROM THE WEST...HOWEVER REMAINING SW WITH NO GUSTING.
ELSEWHERE...MUCH THE SAME AS KCLT ABOVE WITH AFTERNOON CONVECTION
LEADING TO POSSIBLE MVFR VISB RESTRICTIONS. INITIALIZED ALL TAFS
WITH NO WX MENTION ASIDE FOR KAVL WHERE VCTS PREVAILED DUE TO
PROXIMITY OF CURRENT RADAR ECHOES. NEVERTHELESS...ALL SITES HAVE
TEMPOS THIS AFTERNOON FOR ABOVE MENTIONED CONVECTION.
OTHERWISE...LOW VFR CIGS LIFT OVERNIGHT AS CONVECTION DIES DOWN AND
A COLD FRONT APPROACHES FROM THE WEST. THUS...KEPT ALL TAFS VFR
WITH THE EXCEPTION OF LIGHT MVFR BR AT KAVL/KHKY AMIDST LIGHT/CALM
SSW FLOW. WINDS WILL GRADUALLY START TO VEER WESTERLY NEAR PERIODS
END WITH KAVL BEING THE ONLY SITE WITH POST FROPA NW FLOW. WINDS
WILL LIKELY BE GUSTY ALONG AND BEHIND THE FRONTAL PASSAGE ON
TUESDAY...HOWEVER BEYOND THIS TAF CYCLE.
OUTLOOK...A COLD FRONT WILL CROSS THE AREA ON TUESDAY...POSSIBLY
BRINGING ANOTHER ROUND OF DIURNAL SHRA AND TSRA. DRIER AIR WILL MOVE
IN ON WEDNESDAY...BUT THE FRONT MAY STALL JUST TO THE
SOUTH...POSSIBLY ALLOWING UNSETTLED CONDITIONS TO RETURN TO THE AREA
LATE IN THE WEEK.
CONFIDENCE TABLE...
18-24Z 00-06Z 06-12Z 12-18Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 100% HIGH 97% HIGH 97%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
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...SBK
NEAR TERM...CDG/JDL
SHORT TERM...LG
LONG TERM...LG
AVIATION...CDG
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
659 AM EDT MON MAY 11 2015
.SYNOPSIS...
THE REMNANTS OF ANA WILL TURN NORTHEAST AND MOVE ACROSS EASTERN
TODAY...BEFORE MOVING OFF THE VIRGINIA COAST. A COLD FRONT WILL
CROSS OUR AREA ON TUESDAY. HIGH PRESSURE WILL MOVE FROM THE GREAT
LAKES WEDNESDAY TO OFF THE MID ATLANTIC COAST BY NEXT WEEKEND AS
MOISTURE FLOWS UP FROM THE GULF AND INTO OUR AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 655 AM...EARLIER CONVECTION HAS DISSIPATED. IN FACT...SKIES
ARE CLEAR ACROSS MUCH OF THE FORECAST AREA...EXCEPT FOR SOME AREAS
OF FOG/LOW STRATUS ACROSS THE MTN VALLEYS. THE CLEAR SKIES SHOULD
ALLOW TEMPS TO SOAR INTO THE 70S AND LOWER 80S BY LATE MORNING.
AS OF 310 AM...ISOLATED CONVECTION CONTINUES TO FIRE ALONG A
GRADIENT IN MUCAPE SOUTH OF THE I-85 CORRIDOR THIS MORNING. WILL
CONTINUE TO RETAIN 20 POPS IN THIS AREA THROUGH ABOUT DAYBREAK.
OTHERWISE...ATTENTION TURNS TO THE CONVECTIVE POTENTIAL FOR LATER
TODAY. DEWPOINTS IN THE MID/UPPER 60S ARE EXPECTED TO COMBINE WITH
STEEP LOW LEVEL LAPSE RATES TO YIELD SOME OF THE MORE ROBUST CAPE
VALUES WE/VE SEEN IN RECENT DAYS...WITH A CONSENSUS OF DETERMINISTIC
AND ENSEMBLE GUIDANCE CLEARLY SUPPORTING SBCAPE IN THE 2000-2500
J/KG RANGE THIS AFTERNOON. IN ADDITION...MOISTURE WILL BE MORE
PLENTIFUL THROUGH A DEEP LAYER...WITH PWATS OF AROUND 1.5...OR ABOUT
2 STANDARD DEVS ABOVE CLIMO...EXPECTED ACROSS THE PIEDMONT THIS PM.
WHAT WILL BE LACKING IS AN OBVIOUS SOURCE OF ORGANIZED LIFT.
HOWEVER...IT IS INTERESTING THAT SOME OF THE CONVECTION-ALLOWING
MODELS...AND EVEN THE NAM APPEAR TO BE HIGHLIGHTING A LOW LEVEL
CONVERGENCE AXIS ACROSS EAST TENN AND NORTH GA. THE HRRR AND NSSL
WRF LIGHT THIS AREA UP...SUGGESTING (AT LEAST) NUMEROUS CONVECTIVE
COVERAGE BY EARLY/MID AFTERNOON...WHICH WOULD PUSH INTO OUR AREA
BY MID/LATE AFTERNOON. LIKELY POPS WILL BE CARRIED OVER THE
MTNS...WHERE DIFF HEATING STILL APPEARS TO BE THE BEST BET FOR
INITIATING CONVECTION. HOWEVER...POPS HAVE ALSO BEEN BUMPED TO 50
PERCENT ACROSS MUCH OF THE REMAINDER OF THE WESTERN HALF OF THE
FORECAST AREA. IF THE MESOSCALE MODELS HAVE THE RIGHT IDEA...
THIS WILL BE TOO LOW. WHILE PROFILES ARE GENERALLY MOIST...STEEP
LOW LEVEL LAPSE RATES/A HOT BOUNDARY LAYER SHOULD YIELD
DOWNDRAFT CAPE IN THE 500-1000 J/KG RANGE THIS AFTERNOON...WHICH
COULD COMBINE WITH WEAK SHEAR AND WATER LOADING TO YIELD A WET
MICROBURST THREAT WITH SOME OF THE STRONGER UPDRAFTS. WHILE DEEP
LAYER SHEAR IS WEAK...THERE COULD BE JUST ENOUGH SHEAR OVER COLD
POOL DEPTH TO PROMOTE SOME DEGREE OF LIMITED UPSCALE ORGANIZATION...
WHICH WOULD RESULT IN A MORE ORGANIZED DOWNBURST THREAT.
COVERAGE OF CONVECTION WILL GRADUALLY DIMINISH TONIGHT. A COLD FRONT
WILL APPROACH THE SOUTHERN APPALACHIANS FROM THE TENN VALLEY
OVERNIGHT. HOWEVER...THERE IS A DEFINITIVE MODEL CONSENSUS
SUGGESTING THAT ANY ASSOCIATED CONVECTION WILL BE DIMINISHING AS THE
BOUNDARY NUDGES INTO THE FORECAST AREA TOWARD DAYBREAK. TOKEN SMALL
CHANCE POPS WILL NEVERTHELESS BE RETAINED. TEMPERATURES WILL REMAIN
A SOLID 10 DEGREES ABOVE CLIMO THROUGH THE PERIOD.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AT 300 AM EDT MONDAY...ON TUESDAY MORNING NEARLY ZONAL FLOW WILL
EXTEND FROM THE SOUTHERN ROCKIES TO THE MID ATLANTIC COAST...WHILE
AN UPPER TROUGH CROSSES THE GREAT LAKES. ON WEDNESDAY AND UPPER
RIDGE AMPLIFIES OVER THE MS RIVER VALLEY. ON WEDNESDAY NIGHT THIS
RIDGE PROGRESSES TO THE TN AND OH RIVER VALLEYS AND THE GREAT LAKES.
A COLD FRONT WILL CROSS OUR AREA EARLY TUESDAY...ACCOMPANIED BY
PRECIPITATION. INSTABILITY WILL SUPPORT THUNDERSTORMS ALONG AND AHEAD
OF THE FRONT...AND SOME SHEAR WILL BE PRESENT...PERHAPS SUPPORTING
SOME ORGANIZATION TO THE STORMS.
THE FRONT STALLS NEAR THE GULF COAST ON TUESDAY NIGHT...WHILE DRIER
AIR MOVES INTO OUR AREA FROM THE NW. DRY HIGH PRESSURE BUILDS DOWN
THE EAST SLOPES OF THE APPALACHIANS ON WEDNESDAY NIGHT...WHILE THE
STALLED FRONT REMAINS TO OUR S. TEMPERATURES WILL RUN WELL ABOVE
NORMAL IN DOWNSLOPE WARMING BEHIND THE FRONT...COOLING TO SLIGHTLY
ABOVE NORMAL AS COOLING WITH THE POST FRONTAL AIR MASS IS OFFSET BY
RISING HEIGHTS ALOFT.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AT 300 AM EDT MONDAY...ON THURSDAY MORNING AND UPPER RIDGE WILL BE
CENTERED OVER SW FL...EXTENDING N TO THE GREAT LAKES...WHILE TROUGHS
WILL BE OFF THE WEST AND EAST COASTS. A WELL DEFINED SHORTWAVE WILL
BE MOVING ACROSS THE PLAIN AT THAT TIME. BY FRIDAY MORNING THE
SHORTWAVE CROSSES THE UPPER MS RIVER VALLEY...AND BY SATURDAY
MORNING IT WEAKENS OVER THE NORTHEAST. MEANWHILE...THE UPPER RIDGE
REMAINS FROM THE GULF TO THE GREAT LAKES...WHILE A CLOSED LOW MOVES
INLAND FROM THE CA COAST TO UT. BY SUNDAY THE RIDGE AXIS PROGRESSES
TO THE APPALACHIANS...WHILE THE UPPER LOW MOVES INTO WY...AND
ANOTHER UPPER LOW APPROACHES THE CA COAST.
AT THE SURFACE...HIGH PRESSURE WILL EXTEND FROM THE GREAT LAKES TO
THE EAST COAST AND GULF STATES THURSDAY MORNING...WHILE A STATIONARY
FRONT EXTENDS FROM N FL TO THE GULF COAST. ON FRIDAY THE SURFACE
RIDGE WILL BE OVER THE EASTERN SEABOARD...WHILE GULF INFLOW SETS UP
TO THE WEST. ISENTROPIC UPGLIDE OVER THE SURFACE RIDGE WILL SUPPORT
PRECIPITATION OVER OUR AREA...BUT INSTABILITY APPEARS TO BE LACKING
AT THIS TIME.
THE SURFACE RIDGE MOVES OFF THE EAST COAST ON SATURDAY...ALLOWING
GULF INFLOW TO SPREAD EAST TOWARD THE SOUTHERN APPALACHIANS....AND
THIS PATTERN PERSISTS INTO SUNDAY. INCREASING INSTABILITY WILL
SUPPORT A RETURN OF THUNDERSTORMS...BUT AT THIS POINT SHEAR APPEARS
TO BE QUITE LIMITED...AND ORGANIZED CONVECTION UNLIKELY.
TEMPERATURES WILL EXHIBIT A REDUCED DIURNAL RANGE DUE TO CLOUD COVER
AND INCREASING MOISTURE.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AT KCLT AND ELSEWHERE (EXCEPT MTN VALLEYS)...VFR CONDITIONS ARE
GENERALLY EXPECTED UNTIL AFTERNOON...ALTHOUGH BRIEF MVFR VISBY WILL
BE POSSIBLE EARLY THIS MORNING...ESP AT KAND/KHKY. WINDS WILL BECOME
SW AT 7-10 KTS AT MOST TERMINALS THIS AFTERNOON...WITH GUSTS IN THE
TEENS POSSIBLE. THE PRIMARY CONCERN FOR THE FORECAST PERIOD WILL BE
THE POTENTIAL FOR DEEP CONVECTION LATER TODAY...WHICH SHOULD BE
QUITE A BIT HIGHER THAN IN RECENT DAYS. THIS IS DUE TO IMPROVING
MOISTURE AND INSTABILITY PROFILES. THERE IS STILL SOME QUESTION AS
TO HOW EXTENSIVE COVERAGE WILL BE...BUT CURRENT INDICATIONS ARE THAT
COVERAGE WILL BE GREATEST ACROSS UPSTATE SC AND THE NC MTNS.
NEVERTHELESS...PROB30S ARE CERTAINLY WARRANTED AT ALL TERMINALS FROM
MID-AFTERNOON ON. TEMPOS WILL LIKELY NEED TO BE ADDED TO SOME OR ALL
OF THE TERMINALS AT SOME POINT...BUT TIMING IS TOO UNCERTAIN TO
INCLUDE ATTM.
AT KAVL/MTN VALLEYS...LIFR/BRIEF VLIFR CONDITIONS WILL PERSIST IN
THE MTN VALLEYS UNTIL 14Z OR SO. OTHERWISE...CONVECTION IS EXPECTED
TO DEVELOP OVER THE HIGH TERRAIN SURROUNDING THE MTN TERMINALS BY
EARLY AFTERNOON...AND A CATEGORICAL MENTION OF SHRA/VCTS STILL
APPEARS WARRANTED BY MID-AFTERNOON. COVERAGE OF CONVECTION WILL
DIMINISH THIS EVENING...BUT AT LEAST ISOLATED SHOWERS SHOULD LINGER
INTO THE OVERNIGHT. ANOTHER ROUND OF FOG/STRATUS IS POSSIBLE LATE
TONIGHT...BUT CONDITIONS ARE TOO UNCERTAIN TO FORECAST RESTRICTIONS
ATTM.
OUTLOOK...A COLD FRONT WILL CROSS THE AREA ON TUESDAY...BRINGING
ANOTHER ROUND OF DIURNAL SHRA AND TSRA. DRIER AIR WILL MOVE IN ON
WEDNESDAY...BUT THE FRONT MAY STALL JUST TO THE SOUTH...POSSIBLY
ALLOWING UNSETTLED CONDITIONS TO RETURN TO THE AREA LATE IN THE WEEK.
CONFIDENCE TABLE...
11-17Z 17-23Z 23-05Z 05-06Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL MED 62% HIGH 100% HIGH 100% HIGH 100%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
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...JAT
NEAR TERM...JDL
SHORT TERM...JAT
LONG TERM...JAT
AVIATION...JDL
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
340 AM EDT MON MAY 11 2015
.SYNOPSIS...
THE REMNANTS OF ANA WILL TURN NORTHEAST AND MOVE ACROSS EASTERN
TODAY...BEFORE MOVING OFF THE VIRGINIA COAST. A COLD FRONT WILL
CROSS OUR AREA ON TUESDAY. HIGH PRESSURE WILL MOVE FROM THE GREAT
LAKES WEDNESDAY TO OFF THE MID ATLANTIC COAST BY NEXT WEEKEND AS
MOISTURE FLOWS UP FROM THE GULF AND INTO OUR AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 310 AM...ISOLATED CONVECTION CONTINUES TO FIRE ALONG A
GRADIENT IN MUCAPE SOUTH OF THE I-85 CORRIDOR THIS MORNING. WILL
CONTINUE TO RETAIN 20 POPS IN THIS AREA THROUGH ABOUT DAYBREAK.
OTHERWISE...ATTENTION TURNS TO THE CONVECTIVE POTENTIAL FOR LATER
TODAY. DEWPOINTS IN THE MID/UPPER 60S ARE EXPECTED TO COMBINE WITH
STEEP LOW LEVEL LAPSE RATES TO YIELD SOME OF THE MORE ROBUST CAPE
VALUES WE/VE SEEN IN RECENT DAYS...WITH A CONSENSUS OF DETERMINISTIC
AND ENSEMBLE GUIDANCE CLEARLY SUPPORTING SBCAPE IN THE 2000-2500
J/KG RANGE THIS AFTERNOON. IN ADDITION...MOISTURE WILL BE MORE
PLENTIFUL THROUGH A DEEP LAYER...WITH PWATS OF AROUND 1.5...OR ABOUT
2 STANDARD DEVS ABOVE CLIMO...EXPECTED ACROSS THE PIEDMONT THIS PM.
WHAT WILL BE LACKING IS AN OBVIOUS SOURCE OF ORGANIZED LIFT.
HOWEVER...IT IS INTERESTING THAT SOME OF THE CONVECTION-ALLOWING
MODELS...AND EVEN THE NAM APPEAR TO BE HIGHLIGHTING A LOW LEVEL
CONVERGENCE AXIS ACROSS EAST TENN AND NORTH GA. THE HRRR AND NSSL
WRF LIGHT THIS AREA UP...SUGGESTING (AT LEAST) NUMEROUS CONVECTIVE
COVERAGE BY EARLY/MID AFTERNOON...WHICH WOULD PUSH INTO OUR AREA
BY MID/LATE AFTERNOON. LIKELY POPS WILL BE CARRIED OVER THE
MTNS...WHERE DIFF HEATING STILL APPEARS TO BE THE BEST BET FOR
INITIATING CONVECTION. HOWEVER...POPS HAVE ALSO BEEN BUMPED TO 50
PERCENT ACROSS MUCH OF THE REMAINDER OF THE WESTERN HALF OF THE
FORECAST AREA. IF THE MESOSCALE MODELS HAVE THE RIGHT IDEA...
THIS WILL BE TOO LOW. WHILE PROFILES ARE GENERALLY MOIST...STEEP
LOW LEVEL LAPSE RATES/A HOT BOUNDARY LAYER SHOULD YIELD
DOWNDRAFT CAPE IN THE 500-1000 J/KG RANGE THIS AFTERNOON...WHICH
COULD COMBINE WITH WEAK SHEAR AND WATER LOADING TO YIELD A WET
MICROBURST THREAT WITH SOME OF THE STRONGER UPDRAFTS. WHILE DEEP
LAYER SHEAR IS WEAK...THERE COULD BE JUST ENOUGH SHEAR OVER COLD
POOL DEPTH TO PROMOTE SOME DEGREE OF LIMITED UPSCALE ORGANIZATION...
WHICH WOULD RESULT IN A MORE ORGANIZED DOWNBURST THREAT.
COVERAGE OF CONVECTION WILL GRADUALLY DIMINISH TONIGHT. A COLD FRONT
WILL APPROACH THE SOUTHERN APPALACHIANS FROM THE TENN VALLEY
OVERNIGHT. HOWEVER...THERE IS A DEFINITIVE MODEL CONSENSUS
SUGGESTING THAT ANY ASSOCIATED CONVECTION WILL BE DIMINISHING AS THE
BOUNDARY NUDGES INTO THE FORECAST AREA TOWARD DAYBREAK. TOKEN SMALL
CHANCE POPS WILL NEVERTHELESS BE RETAINED. TEMPERATURES WILL REMAIN
A SOLID 10 DEGREES ABOVE CLIMO THROUGH THE PERIOD.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AT 300 AM EDT MONDAY...ON TUESDAY MORNING NEARLY ZONAL FLOW WILL
EXTEND FROM THE SOUTHERN ROCKIES TO THE MID ATLANTIC COAST...WHILE
AN UPPER TROUGH CROSSES THE GREAT LAKES. ON WEDNESDAY AND UPPER
RIDGE AMPLIFIES OVER THE MS RIVER VALLEY. ON WEDNESDAY NIGHT THIS
RIDGE PROGRESSES TO THE TN AND OH RIVER VALLEYS AND THE GREAT LAKES.
A COLD FRONT WILL CROSS OUR AREA EARLY TUESDAY...ACCOMPANIED BY
PRECIPITATION. INSTABILITY WILL SUPPORT THUNDERSTORMS ALONG AND
AHEAD OF THE FRONT...AND SOME SHEAR WILL BE PRESENT...PERHAPS
SUPPORTING SOME ORGANIZATION TO THE STORMS.
THE FRONT STALLS NEAR THE GULF COAST ON TUESDAY NIGHT...WHILE DRIER
AIR MOVES INTO OUR AREA FROM THE NW. DRY HIGH PRESSURE BUILDS DOWN
THE EAST SLOPES OF THE APPALACHIANS ON WEDNESDAY NIGHT...WHILE THE
STALLED FRONT REMAINS TO OUR S. TEMPERATURES WILL RUN WELL ABOVE
NORMAL IN DOWNSLOPE WARMING BEHIND THE FRONT...COOLING TO SLIGHTLY
ABOVE NORMAL AS COOLING WITH THE POST FRONTAL AIR MASS IS OFFSET BY
RISING HEIGHTS ALOFT.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AT 300 AM EDT MONDAY...ON THURSDAY MORNING AND UPPER RIDGE WILL BE
CENTERED OVER SW FL...EXTENDING N TO THE GREAT LAKES...WHILE TROUGHS
WILL BE OFF THE WEST AND EAST COASTS. A WELL DEFINED SHORTWAVE WILL
BE MOVING ACROSS THE PLAIN AT THAT TIME. BY FRIDAY MORNING THE
SHORTWAVE CROSSES THE UPPER MS RIVER VALLEY...AND BY SATURDAY
MORNING IT WEAKENS OVER THE NORTHEAST. MEANWHILE...THE UPPER RIDGE
REMAINS FROM THE GULF TO THE GREAT LAKES...WHILE A CLOSED LOW MOVES
INLAND FROM THE CA COAST TO UT. BY SUNDAY THE RIDGE AXIS PROGRESSES
TO THE APPALACHIANS...WHILE THE UPPER LOW MOVES INTO WY...AND
ANOTHER UPPER LOW APPROACHES THE CA COAST.
AT THE SURFACE...HIGH PRESSURE WILL EXTEND FROM THE GREAT LAKES TO
THE EAST COAST AND GULF STATES THURSDAY MORNING...WHILE A STATIONARY
FRONT EXTENDS FROM N FL TO THE GULF COAST. ON FRIDAY THE SURFACE
RIDGE WILL BE OVER THE EASTERN SEABOARD...WHILE GULF INFLOW SETS UP
TO THE WEST. ISENTROPIC UPGLIDE OVER THE SURFACE RIDGE WILL SUPPORT
PRECIPITATION OVER OUR AREA...BUT INSTABILITY APPEARS TO BE LACKING
AT THIS TIME.
THE SURFACE RIDGE MOVES OFF THE EAST COAST ON SATURDAY...ALLOWING
GULF INFLOW TO SPREAD EAST TOWARD THE SOUTHERN APPALACHIANS....AND
THIS PATTERN PERSISTS INTO SUNDAY. INCREASING INSTABILITY WILL
SUPPORT A RETURN OF THUNDERSTORMS...BUT AT THIS POINT SHEAR
APPEARS TO BE QUITE LIMITED...AND ORGANIZED CONVECTION UNLIKELY.
TEMPERATURES WILL EXHIBIT A REDUCED DIURNAL RANGE DUE TO CLOUD COVER
AND INCREASING MOISTURE.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
AT KCLT AND ELSEWHERE (EXCEPT MTN VALLEYS)...VFR CONDITIONS ARE
GENERALLY EXPECTED UNTIL AFTERNOON...ALTHOUGH BRIEF MVFR VISBY WILL
BE POSSIBLE TOWARD DAYBREAK. IN FACT...THE POTENTIAL IS HIGH ENOUGH
TO INCLUDE TEMPOS FOR SUCH AT KAND/KHKY. OTHERWISE...SCT/BKN
STRATOCU IN THE 050-080 RANGE IS EXPECTED THROUGH MUCH OF THE
MORNING. THE PRIMARY CONCERN FOR THE FORECAST PERIOD WILL BE THE
POTENTIAL FOR DEEP CONVECTION LATER TODAY...WHICH SHOULD BE QUITE A
BIT HIGHER THAN IN RECENT DAYS. THIS IS DUE TO IMPROVING MOISTURE
AND INSTABILITY PROFILES. THERE IS STILL SOME QUESTION AS TO HOW
EXTENSIVE COVERAGE WILL BE...BUT PROB30S ARE CERTAINLY WARRANTED AT
ALL TERMINALS FROM MID-AFTERNOON ON. TEMPOS WILL NEED TO BE
ENTERTAINED FOR THE 12 TAFS...PARTICULARLY ACROSS AT KHKY AND THE
UPSTATE SC TERMINALS...AS THE MTNS AND NORTH GA APPEAR TO BE GROUND
ZERO FOR CONVECTIVE DEVELOPMENT LATER TODAY...WITH STEERING FLOW
PUSHING CELLS GRADUALLY TO THE EAST.
AT KAVL/MTN VALLEYS...THE MOST IMMEDIATE CONCERN IS THE POTENTIAL
FOR FOG/LOW STRATUS LATER THIS MORNING...WITH MVFR FOG ALREADY BEING
REPORTED IN THE VALLEYS SOUTHWEST OF KAVL. HOWEVER...AREAS OF VFR
STRATOCU AND THE POTENTIAL FOR OCCL LIGHT WINDS ARE CREATING SOME
DOUBTS ABOUT THE POTENTIAL AT KAVL. OPTED TO INCLUDE A TEMPO FOR
MVFR VISBY ALONG WITH SCT003 TOWARD DAYBREAK...BUT BRIEF IFR OR
WORSE CONDITIONS CANNOT BE RULED OUT. OTHERWISE...CONVECTION IS
EXPECTED TO DEVELOP OVER THE HIGH TERRAIN SURROUNDING THE MTN
TERMINALS BY EARLY AFTERNOON...AND A CATEGORICAL MENTION OF
SHRA/VCTS APPEARS WARRANTED BY MID-AFTERNOON.
OUTLOOK...A COLD FRONT WILL CROSS THE AREA ON TUESDAY...BRINGING
ANOTHER ROUND OF DIURNAL SHRA AND TSRA. DRIER AIR WILL MOVE IN ON
WEDNESDAY...BUT THE FRONT MAY STALL JUST TO THE SOUTH...POSSIBLY
ALLOWING UNSETTLED CONDITIONS TO RETURN TO THE AREA LATE IN THE WEEK.
CONFIDENCE TABLE...
07-13Z 13-19Z 19-01Z 01-06Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 85% HIGH 96% HIGH 100% HIGH 100%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
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...JAT
NEAR TERM...JDL
SHORT TERM...JAT
LONG TERM...JAT
AVIATION...JDL
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
926 PM CDT TUE MAY 12 2015
.UPDATE...
ISSUED AT 925 PM CDT TUE MAY 12 2015
STILL A POSSIBILITY OF LLJ/WAA SHOWER/STORM DEVELOPMENT TONIGHT
ALONG THE NORTHERN CWA. THE HRRR MODEL WAS SHOWING SOME DEVELOPMENT
THROUGH THE NIGHT. UNR RADAR WAS ALSO SHOWING SOME SHOWERS MOVING
INTO WESTERN SD THIS EVENING. THUS...LEFT IN THE POPS ACROSS THE
NORTH THROUGH THE NIGHT.
UPDATE ISSUED AT 640 PM CDT TUE MAY 12 2015
00Z AVIATION DISCUSSION UPDATED BELOW.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY AFTERNOON)
ISSUED AT 323 PM CDT TUE MAY 12 2015
MID LEVEL CLOUDS ARE OCCURRING ACROSS PARTS OF SOUTHWEST NORTH
DAKOTA AND NORTHWEST SOUTH DAKOTA IN RESPONSE TO A WEAK UPPER LEVEL
WAVE. THE LOWER LEVELS ARE PRETTY DRY...AND OBS ARE SHOWING CLOUD
BASES AROUND 7K-8K FT...SO EXPECT THAT VERY LITTLE PRECIP IS
REACHING THE GROUND. DID THROW SPRINKLES INTO THE FORECAST FOR GOOD
MEASURE HOWEVER. LATER TONIGHT...A 40+ KT LLJ DEVELOPS...AND THE
CHANCES FOR SHOWERS AND THUNDERSTORMS INCREASE. STILL ON THE DRY
SIDE HOWEVER...SO NOT EXPECTING MUCH IN THE WAY OF ACCUMULATION WITH
ANY SHOWERS OR STORMS.
WEDNESDAY...A MORE POTENT UPPER LEVEL TROUGH APPROACHES FROM THE
SOUTHWEST. AT THE SURFACE AN INVERTED TROUGH WILL EXTEND FROM
SOUTHWEST SOUTH DAKOTA THROUGH NORTH CENTRAL SOUTH DAKOTA. SURFACE
BASED CONVECTION MAY BE POSSIBLE ALONG THIS BOUNDARY LATE
WEDNESDAY AFTERNOON AS ML CAPE VALUES RISE TO AROUND 1000 J/KG.
0-6 KM SHEAR ISNT OVERLY IMPRESSIVE /AROUND 20 KTS/ AND LCLS ARE
FAIRLY HIGH...BUT CANT RULE OUT A FEW STRONGER PULSE STORMS WITH
LARGE HAIL. THE MAIN FORCING ASSOCIATED WITH THE UPPER TROUGH THEN
SPREADS OVER THE REGION LATE WEDNESDAY NIGHT THROUGH THURSDAY.
HIGH CHANCE TO LIKELY POPS ARE IN THE FORECAST FOR THIS TIME
PERIOD.
.LONG TERM...(THURSDAY EVENING THROUGH TUESDAY)
ISSUED AT 323 PM CDT TUE MAY 12 2015
EXTENDED PERIOD STILL APPEARS TO BE AN ACTIVE ONE WITH SEVERAL
CHANCES FOR RAIN. BEGINNING FRIDAY...FIRST SYSTEM IS ALREADY
APPROACHING THE NORTHERN PLAINS. DURING THE DAYTIME HOURS...MODELS
SUGGEST MAINLY WESTERN AND CENTRAL SD SEEING THE BEST CHANCES.
FRIDAY NIGHT LOOKS TO BE THE BEST CHANCE FOR WIDESPREAD
PRECIPITATION OVER THE FORECAST AREA. MODELS ARE ACTUALLY IN RATHER
GOOD AGREEMENT IN TIMING AND PLACEMENT/COVERAGE OF RAIN SO DID NOT
MAKE MANY CHANGES TO THE LIKELY SUPERBLEND POPS. SATURDAY AND
SATURDAY NIGHT COULD BE QUITE INTERESTING AS SOME BETTER INSTABILITY
AND SHEAR SPREAD NORTHWARD ACROSS THE AREA. MODELS ARE AGAIN IN
PRETTY DECENT AGREEMENT IN SHOWING SHORTWAVE ENERGY MOVING ACROSS
THE AREA WITH SHOWERS AND STORMS DEVELOPING DURING THE AFTERNOON AND
EVENING HOURS SATURDAY. LEFT THE HIGH POPS ALONE THAT SUPERBLEND
GAVE AS THIS LOOKS GOOD FOR NOW. IN REGARDS TO THIS STRONGER WEEKEND
SYSTEM...THERE IS STILL SOME DISAGREEMENT IN THE OVERALL EVOLUTION
AND MOVEMENT OF THE MAIN UPPER LOW HEADING INTO EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 640 PM CDT TUE MAY 12 2015
VFR CONDITIONS ARE EXPECTED FOR ALL LOCATIONS THROUGH TONIGHT AND
WEDNESDAY. THERE MAY BE A FEW HIGH BASED SHOWERS AFFECT THE
LOCATIONS THROUGH THE NIGHT. OTHERWISE...BREEZY/WINDY SOUTHEAST
WINDS ARE EXPECTED TO CONTINUE THROUGH TONIGHT AND WEDNESDAY. VERY
STRONG WINDS OFF THE SURFACE MAY BRING SOME LOW LEVEL WIND SHEAR
TONIGHT.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...MOHR
SHORT TERM...SERR
LONG TERM...TMT
AVIATION...MOHR
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
320 PM CDT MON MAY 11 2015
.DISCUSSION...
PRE FRONTAL TROUGHING ATTEMPTING TO INITIATE CONVECTION ACROSS THE
MID STATE TODAY. CAP HAS BEEN WEAK ENOUGH OVER THE PLATEAU AND
WESTERN AREAS SO AS TO ALLOW CONVECTIVE ACTIVITY TO OCCUR. A FEW OF
THE STORMS HAVE BEEN STRONG ACROSS THE PLATEAU AREA. LATEST LAPS
DATA SHOWING AND INCREASE IN INSTABILITIES ACROSS OUR SOUTHWESTERN
ZONES. THE CURRENT LINE OF CONVECTION JUST NOW ENTERING STEWART
COUNTY WILL NEED TO BE WATCHED. HOWEVER...LATEST HRRR AND MODEL QPF
PROGS CONTINUE TO REFRAIN FROM SHOWING MUCH IN THE WAY OF AN
ORGANIZED EVENT.
FOR TONIGHT...THE FRONTAL BOUNDARY WILL PUSH INTO THE MID STATE
AFTER MIDNIGHT. NOT EXPECTING MUCH IN THE WAY OF CONVECTION ALONG
THE MAIN BOUNDARY...IT WILL MOSTLY BE PRE FRONTAL ACTIVITY.
OTW...DECREASING CLOUDS AFTER MIDNIGHT. POP LEVELS...AFT 00Z...WILL
GENERALLY RANGE FROM LESS THAN 20 PERCENT NW TO 40 PERCENT FOR THE
PLATEAU AREA.
TUES THROUGH WED NT WILL FEATURE DRY CONDITIONS WITH SEASONABLE
TEMPS. SFC PATTERN WILL KEEP A LIGHT NORTHERLY FETCH GOING WHILE
UPPER LEVEL RIDGING BUILDS IN. THIS WILL RESULT IN RATHER LARGE
DIURNAL TEMP SWINGS WITH LOWS GENERALLY IN THE LOW TO MID 50S FOR
TUES NT AND WED NT. HIGH TEMPS WILL BE WARMING INTO THE UPPER 70S TO
NEAR 80.
IN THE EXT FCST...PATTERN WILL BEGIN TO CHANGE. THE SFC HIGH...WHICH
BROUGHT THE FAIR WEATHER CONDITIONS TO THE AREA...WILL BE SLIDING
OFF TO THE EAST. A MOIST SOUTHERLY FLOW WILL RETURN AND WILL BE
AIDED BY A SOUTHWESTERLY FLOW IN THE MID AND UPPER LEVELS. IMPULSES
WILL RIDE NORTHEASTWARD AND PROVIDE A PROLONGED THREAT OF SHOWER AND
TSTM ACTIVITY THROUGH MUCH OF THE EXTENDED. BY THE END OF THE
EXTENDED...A FRONTAL BOUNDARY WILL ATTEMPT TO APPROACH. MEANWHILE
CAPE TO CAP RATIOS WILL BECOME MORE FAVORABLE. THUS...THE INTENSITY
OF TSTM ACTIVITY MAY BE ON THE INCREASE.
FOR THE EXT TEMPS...A SLOW WARMING AND HUMIDITY INCREASING TREND
WILL BE IN PLACE. BY THE END OF THE EXTENDED...TEMPS WILL REACH A
GOOD 10 TO 15 DEGREES ABOVE NORMAL.
.PRELIMINARY POINT TEMPS/POPS...
NASHVILLE 59 77 50 79 / 20 05 0 05
CLARKSVILLE 54 76 48 77 / 10 05 0 05
CROSSVILLE 58 73 47 74 / 40 10 05 05
COLUMBIA 59 79 51 80 / 30 10 05 05
LAWRENCEBURG 58 79 51 79 / 30 10 05 0
WAVERLY 55 76 48 78 / 20 05 05 05
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
21
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1249 PM CDT MON MAY 11 2015
.UPDATE...FOR 18Z AVIATION.
&&
.AVIATION...
MAINLY VFR CONDITIONS FOR ALL THREE TERMINALS. SCATTERED
THUNDERSTORMS WILL BE AROUND THIS AFTERNOON. GIVE THE DECREASED
COVERAGE VIA THE HRRR ELECTED TO PUT IN VCTS INSTEAD OF A TEMPO
GROUP. WILL MONITOR THIS AFTERNOON FOR AMENDMENTS. WINDS WILL BE
GUSTY THIS AFTERNOON BEFORE RELAXING TONIGHT AND VEERING DUE TO
FROPA TONIGHT. LAMP DATA SUGGESTING SOME BR FOR CSV TONIGHT. WINDS
MAY STAY UP ENOUGH TO PREVENT THIS BUT INCLUDED TEMPO 5SM FOR
THIS.
REAGAN
&&
.PREV DISCUSSION... /ISSUED 1030 AM CDT MON MAY 11 2015/
UPDATE...
MAIN ITEM OF INTEREST FOR THE TODAY PERIOD IS THE CHANCES FOR A
COUPLE STRONG TO POSSIBLY SEVERE STORMS. SPC HAS OUR SW COUNTIES
HIGHLIGHTED WITH A SLIGHT RISK AND THE REST OF THE AREA WITH A
MARGINAL RISK. HRRR INDICATES 1000-1500 J/KG SBCAPE SNEAKING INTO
THE SOUTHWEST BY 18Z WITH SOME STORMS APPROACHING THAT AREA AT THE
TIME. CURRENTLY RADAR SHOWS SOME STORMS IN THE NORTH CENTRAL MS.
TIMING THESE STORMS OUT PUTS THEM INTO OUR WESTERN COUNTIES AROUND
19Z. LATEST RUN OF THE HRRR IS MORE BULLISH WITH THE AMOUNT OF
PRECIPITATION BROUGHT INTO THE AREA. PREVIOUS RUNS WERE MORE
SCATTERED IN NATURE. TEND TO AGREE WITH THE EARLIER RUNS GIVEN THE
LACK OF CONVERGENCE AND SUPPORT FOR THE STORMS. WITH ALL OF
THIS...KEPT POPS AS THEY WERE.
OVERALL HIGH TEMPERATURES ARE ON PACE. TWEAKED SOME HOURLY TEMPS
ESPECIALLY TO THE EAST WHERE FULL SUN HAS ALLOWED A QUICK WARM UP
BUT WARMING TRENDS SHOULD BE TEMPERED AS CLOUDS MOVE IN FROM THE
WEST.
REAGAN
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
10
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1228 PM CDT MON MAY 11 2015
.UPDATE...
UPDATE FOR THE 18Z AVIATION DISCUSSION
&&
.PREV DISCUSSION... /ISSUED 953 AM CDT MON MAY 11 2015/
UPDATE...
A BAND OF RAIN SHOWERS IS WEAKENING WHILE MOVING IN FROM THE WEST
WITH DEVELOPING SHOWERS AND THUNDERSTORMS SOUTH OF MEMPHIS ALONG
THE INTERSTATE 55 CORRIDOR. THE ATMOSPHERE IS PRETTY WELL WORKED
OVER ALONG AND WEST OF THE MISSISSIPPI RIVER...SO ANY ADDITIONAL
STRONG OR SEVERE STORMS WOULD DEVELOP IN EASTERN PORTIONS OF WEST
TENNESSEE AND IN NORTH MISSISSIPPI EAST ON INTERSTATE 55. CURRENT
THINKING IS THAT THE LINE IN NORTH MISSISSIPPI ALONG INTERSTATE 55
WILL CONTINUE TO STRENGTHEN AS IT SHIFTS EAST AND MAY BUILD
SLIGHTLY FARTHER NORTH INTO WEST TENNESSEE...BUT WILL MOST LIKELY
REMAIN BELOW SEVERE LIMITS AS EXTENSIVE CLOUD COVER OVER THE
REGION CURBS INSTABILITY. UPPER LEVEL SUPPORT FOR SEVERE STORMS
SHOULD CONTINUE TO DIMINISH WITH TIME.
PREV DISCUSSION... /ISSUED 618 AM CDT MON MAY 11 2015/
DISCUSSION...
UPDATED FOR 12Z AVIATION DISCUSSION.
PREV DISCUSSION... /ISSUED 403 AM CDT MON MAY 11 2015/
DISCUSSION...
CURRENTLY...AN UPPER LOW IS CENTERED OVER THE NORTHERN PLAINS
MOVING NORTHEAST. MEANWHILE A MID LEVEL SHORTWAVE IS MOVING
ACROSS THE SOUTHERN PLAINS AND INTO THE LOWER MISSISSIPPI VALLEY.
THIS FEATURE HAS IGNITED AN AREA SHOWERS AND THUNDERSTORMS ACROSS
ARKANSAS INTO THE ARKLATEX REGION. A LEADING EDGE LINE OF SHOWERS
AND THUNDERSTORMS HAS MOVED INTO NORTHEAST ARKANSAS WHERE LOCALLY
HEAVY RAIN IS OCCURRING. RAIN RATES OF OVER 1 INCH PER HOUR HAVE
BEEN NOTED ACROSS RANDOLPH AND LAWRENCE COUNTIES. ELSW ACROSS THE
MIDSOUTH CLOUDS ARE INCREASING AND TEMPS ARE MILD...IN THE UPPER
60S AND LOWER 70S WITH A LIGHT SOUTH WIND.
TODAY...THIS LINE OF SHOWERS AND THUNDERSTORMS WILL PUSH ACROSS
THE MIDSOUTH THIS MORNING. GOOD UPPER LEVEL SUPPORT WILL HELP
MAINTAIN THE SHOWERS AND THUNDERSTORMS THROUGH ABOUT MID MORNING
AS THEY CROSS EASTERN ARKANSAS...THE MISSOURI BOOTHEEL AND THE
MISSISSIPPI RIVER. STRONG LOW LEVEL MOISTURE TRANSPORT INTO THE
DELTA REGION WILL HELP PRODUCE LOCALLY HEAVY RAINFALL...ESPECIALLY
WEST OF THE MISSISSIPPI RIVER WHERE 1 TO 2 INCHES COULD FALL WITH
LOCALLY HIGHER AMOUNTS. A FLASH FLOOD WATCH REMAIN IN EFFECT UNTIL
NOON WEST OF THE RIVER. MLCAPE VALUES ARE ABOUT 500 J/KG AHEAD OF
THE LINE OF THUNDERSTORMS ACROSS THE DELTA AND BULK SHEAR VALUES
ARE GREATER THAN 40 KTS. AS A RESULT A FEW STORMS COULD BE STRONG
TO SEVERE...MAINLY WEST OF THE MISSISSIPPI RIVER THROUGH ABOUT MID
MORNING. DAMAGING WIND IS THE MAIN THREAT.
AS THE LINE HEADS EAST OF THE MISSISSIPPI RIVER IT WILL WEAKEN AS
THE BETTER UPPER SUPPORT LIFTS NORTHEAST. THE LATEST HRRR DEPICTS
THE REMNANTS OF THE LINE REACHING THE TN RIVER BY ABOUT 18Z.
THERE IS THE QUESTION OF REDEVELOPMENT ALONG THE COLD FRONT AS IT
MOVES INTO THE AREA LATER TODAY AND THIS EVENING. ATTM IT LOOKS
LIKE REDEVELOPMENT WILL BE RATHER MEAGER. FIRST THE COLD FRONT IS
WEAKENING AS IT MOVES INTO THE REGION AND CONVERGENCE ALONG THE
FRONT IS WEAK. ALSO EXPECT A GOOD DEAL OF STRATIFORM RAIN BEHIND
THE INITIAL LINE OF THUNDERSTORMS THAT WILL LAST MUCH OF THE
MORNING. THIS WILL SERVE TO STABILIZE THE AIRMASS AND REALLY DO
NOT SEE IT RECOVERING ENOUGH TO PROMOTE DEVELOPMENT LATER THIS
AFTERNOON INTO THE EVENING. LASTLY MID LEVEL HEIGHTS START TO
RISE. THIS SCENARIO JUST DOES NOT LOOK FAVORABLE FOR
REDEVELOPMENT AND THE LATEST HRRR CORROBORATES THAT.
THE AREA WILL START TO DRY OUT FROM THE NORTHWEST THIS AFTERNOON.
TONIGHT...LEFT SOME LINGERING SHOWERS AND THUNDERSTORMS SOUTH OF
I-40 FOR THE EVENING AS THE WEAK COLD FRONT PUSHES THROUGH. OTRW
SKIES WILL BE CLEARING OVERNIGHT AS SURFACE HIGH PRESSURE STARTS
TO BUILD IN. LOWS WILL DROP INTO THE 50S NORTH TO LOWER 60S
SOUTH.
TUESDAY AND WEDNESDAY...THESE LOOK LIKE SOME VERY NICE DAYS WITH
LOW HUMIDITY AND PLEASANT TEMPS AS HIGH PRESSURE PREVAILS. HIGHS
WILL BE IN THE 70S. LOWS WEDNESDAY MORNING COULD DIP INTO THE
UPPER 40S IN THE COOLER SPOTS.
THURSDAY THROUGH SUNDAY...FRONT WILL LIFT BACK NORTH AS WARM
FRONT AND THE HUMIDITY LEVELS WILL INCREASE LATER IN THE WEEK. THE
UPPER FLOW WILL TRANSITION BACK TO SOUTHWEST FLOW WITH CHANCES
FOR SHOWERS AND THUNDERSTORMS AS DISTURBANCES MOVE THROUGH ALOFT.
HIGH TEMPS WILL BE IN THE LOWER TO MID 80S BY THE END OF THE WEEK
WITH LOWS IN THE 60S.
SJM
&&
.AVIATION...
18Z TAF CYCLE
CURRENT MVFR CEILINGS AT KJBR SHOULD IMPROVE LATER THIS AFTERNOON
OTHERWISE VFR CONDITIONS WILL PERSIST FOR MUCH OF THE FORECAST
PERIOD. SOME SHOWERS AND THUNDERSTORMS WILL MOVE ACROSS MAINLY
EASTERN SECTIONS OF THE FORECAST AREA THIS AFTERNOON. WINDS WILL
BE MAINLY FROM THE WEST AROUND 10 KNOTS FOR MOST OF THE FORECAST
PERIOD.
ARS
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1030 AM CDT MON MAY 11 2015
.UPDATE...
MAIN ITEM OF INTEREST FOR THE TODAY PERIOD IS THE CHANCES FOR A
COUPLE STRONG TO POSSIBLY SEVERE STORMS. SPC HAS OUR SW COUNTIES
HIGHLIGHTED WITH A SLIGHT RISK AND THE REST OF THE AREA WITH A
MARGINAL RISK. HRRR INDICATES 1000-1500 J/KG SBCAPE SNEAKING INTO
THE SOUTHWEST BY 18Z WITH SOME STORMS APPROACHING THAT AREA AT THE
TIME. CURRENTLY RADAR SHOWS SOME STORMS IN THE NORTH CENTRAL MS.
TIMING THESE STORMS OUT PUTS THEM INTO OUR WESTERN COUNTIES AROUND
19Z. LATEST RUN OF THE HRRR IS MORE BULLISH WITH THE AMOUNT OF
PRECIPITATION BROUGHT INTO THE AREA. PREVIOUS RUNS WERE MORE
SCATTERED IN NATURE. TEND TO AGREE WITH THE EARLIER RUNS GIVEN THE
LACK OF CONVERGENCE AND SUPPORT FOR THE STORMS. WITH ALL OF
THIS...KEPT POPS AS THEY WERE.
OVERALL HIGH TEMPERATURES ARE ON PACE. TWEAKED SOME HOURLY TEMPS
ESPECIALLY TO THE EAST WHERE FULL SUN HAS ALLOWED A QUICK WARM UP
BUT WARMING TRENDS SHOULD BE TEMPERED AS CLOUDS MOVE IN FROM THE
WEST.
REAGAN
&&
.PREV DISCUSSION... /ISSUED 628 AM CDT MON MAY 11 2015/
UPDATE...FOR AVIATION.
AVIATION...
12Z TAFS...SCATTERED TSRA WILL DEVELOP OVER THE AREA TODAY AHEAD
OF A COLD FRONT. SOME SEVERE STORMS ARE POSSIBLE. OUTSIDE ANY
TSRA...VFR EXPECTED WITH GUSTY SSW WINDS TO 22KT AT TIMES. TSRA
CHANCES WILL DECREASE TONIGHT. WINDS WILL DIMINISH AND VEER TO
THE NW OVERNIGHT.
13
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
10
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
953 AM CDT MON MAY 11 2015
.UPDATE...
A BAND OF RAIN SHOWERS IS WEAKENING WHILE MOVING IN FROM THE WEST
WITH DEVELOPING SHOWERS AND THUNDERSTORMS SOUTH OF MEMPHIS ALONG
THE INTERSTATE 55 CORRIDOR. THE ATMOSPHERE IS PRETTY WELL WORKED
OVER ALONG AND WEST OF THE MISSISSIPPI RIVER...SO ANY ADDITIONAL
STRONG OR SEVERE STORMS WOULD DEVELOP IN EASTERN PORTIONS OF WEST
TENNESSEE AND IN NORTH MISSISSIPPI EAST ON INTERSTATE 55. CURRENT
THINKING IS THAT THE LINE IN NORTH MISSISSIPPI ALONG INTERSTATE 55
WILL CONTINUE TO STRENGTHEN AS IT SHIFTS EAST AND MAY BUILD
SLIGHTLY FARTHER NORTH INTO WEST TENNESSEE...BUT WILL MOST LIKELY
REMAIN BELOW SEVERE LIMITS AS EXTENSIVE CLOUD COVER OVER THE
REGION CURBS INSTABILITY. UPPER LEVEL SUPPORT FOR SEVERE STORMS
SHOULD CONTINUE TO DIMINISH WITH TIME.
&&
.PREV DISCUSSION... /ISSUED 618 AM CDT MON MAY 11 2015/
DISCUSSION...
UPDATED FOR 12Z AVIATION DISCUSSION.
PREV DISCUSSION... /ISSUED 403 AM CDT MON MAY 11 2015/
DISCUSSION...
CURRENTLY...AN UPPER LOW IS CENTERED OVER THE NORTHERN PLAINS
MOVING NORTHEAST. MEANWHILE A MID LEVEL SHORTWAVE IS MOVING
ACROSS THE SOUTHERN PLAINS AND INTO THE LOWER MISSISSIPPI VALLEY.
THIS FEATURE HAS IGNITED AN AREA SHOWERS AND THUNDERSTORMS ACROSS
ARKANSAS INTO THE ARKLATEX REGION. A LEADING EDGE LINE OF SHOWERS
AND THUNDERSTORMS HAS MOVED INTO NORTHEAST ARKANSAS WHERE LOCALLY
HEAVY RAIN IS OCCURRING. RAIN RATES OF OVER 1 INCH PER HOUR HAVE
BEEN NOTED ACROSS RANDOLPH AND LAWRENCE COUNTIES. ELSW ACROSS THE
MIDSOUTH CLOUDS ARE INCREASING AND TEMPS ARE MILD...IN THE UPPER
60S AND LOWER 70S WITH A LIGHT SOUTH WIND.
TODAY...THIS LINE OF SHOWERS AND THUNDERSTORMS WILL PUSH ACROSS
THE MIDSOUTH THIS MORNING. GOOD UPPER LEVEL SUPPORT WILL HELP
MAINTAIN THE SHOWERS AND THUNDERSTORMS THROUGH ABOUT MID MORNING
AS THEY CROSS EASTERN ARKANSAS...THE MISSOURI BOOTHEEL AND THE
MISSISSIPPI RIVER. STRONG LOW LEVEL MOISTURE TRANSPORT INTO THE
DELTA REGION WILL HELP PRODUCE LOCALLY HEAVY RAINFALL...ESPECIALLY
WEST OF THE MISSISSIPPI RIVER WHERE 1 TO 2 INCHES COULD FALL WITH
LOCALLY HIGHER AMOUNTS. A FLASH FLOOD WATCH REMAIN IN EFFECT UNTIL
NOON WEST OF THE RIVER. MLCAPE VALUES ARE ABOUT 500 J/KG AHEAD OF
THE LINE OF THUNDERSTORMS ACROSS THE DELTA AND BULK SHEAR VALUES
ARE GREATER THAN 40 KTS. AS A RESULT A FEW STORMS COULD BE STRONG
TO SEVERE...MAINLY WEST OF THE MISSISSIPPI RIVER THROUGH ABOUT MID
MORNING. DAMAGING WIND IS THE MAIN THREAT.
AS THE LINE HEADS EAST OF THE MISSISSIPPI RIVER IT WILL WEAKEN AS
THE BETTER UPPER SUPPORT LIFTS NORTHEAST. THE LATEST HRRR DEPICTS
THE REMNANTS OF THE LINE REACHING THE TN RIVER BY ABOUT 18Z.
THERE IS THE QUESTION OF REDEVELOPMENT ALONG THE COLD FRONT AS IT
MOVES INTO THE AREA LATER TODAY AND THIS EVENING. ATTM IT LOOKS
LIKE REDEVELOPMENT WILL BE RATHER MEAGER. FIRST THE COLD FRONT IS
WEAKENING AS IT MOVES INTO THE REGION AND CONVERGENCE ALONG THE
FRONT IS WEAK. ALSO EXPECT A GOOD DEAL OF STRATIFORM RAIN BEHIND
THE INITIAL LINE OF THUNDERSTORMS THAT WILL LAST MUCH OF THE
MORNING. THIS WILL SERVE TO STABILIZE THE AIRMASS AND REALLY DO
NOT SEE IT RECOVERING ENOUGH TO PROMOTE DEVELOPMENT LATER THIS
AFTERNOON INTO THE EVENING. LASTLY MID LEVEL HEIGHTS START TO
RISE. THIS SCENARIO JUST DOES NOT LOOK FAVORABLE FOR
REDEVELOPMENT AND THE LATEST HRRR CORROBORATES THAT.
THE AREA WILL START TO DRY OUT FROM THE NORTHWEST THIS AFTERNOON.
TONIGHT...LEFT SOME LINGERING SHOWERS AND THUNDERSTORMS SOUTH OF
I-40 FOR THE EVENING AS THE WEAK COLD FRONT PUSHES THROUGH. OTRW
SKIES WILL BE CLEARING OVERNIGHT AS SURFACE HIGH PRESSURE STARTS
TO BUILD IN. LOWS WILL DROP INTO THE 50S NORTH TO LOWER 60S
SOUTH.
TUESDAY AND WEDNESDAY...THESE LOOK LIKE SOME VERY NICE DAYS WITH
LOW HUMIDITY AND PLEASANT TEMPS AS HIGH PRESSURE PREVAILS. HIGHS
WILL BE IN THE 70S. LOWS WEDNESDAY MORNING COULD DIP INTO THE
UPPER 40S IN THE COOLER SPOTS.
THURSDAY THROUGH SUNDAY...FRONT WILL LIFT BACK NORTH AS WARM
FRONT AND THE HUMIDITY LEVELS WILL INCREASE LATER IN THE WEEK. THE
UPPER FLOW WILL TRANSITION BACK TO SOUTHWEST FLOW WITH CHANCES
FOR SHOWERS AND THUNDERSTORMS AS DISTURBANCES MOVE THROUGH ALOFT.
HIGH TEMPS WILL BE IN THE LOWER TO MID 80S BY THE END OF THE WEEK
WITH LOWS IN THE 60S.
SJM
&&
.AVIATION...12Z TAFS
LINE OF TSTMS WILL ADVANCE THROUGH THE TAF SITES EARLY...WITH TUP
BEING LEAST AFFECTED. EXPECT IFR/MVFR CONDITIONS WITHIN THE
HEAVIEST ACTIVITY AND VARIABLE WIND GUSTS. OUTSIDE OF STORMS
WEATHER WILL BE VFR WITH SOUTHWEST WINDS INCREASING TO 10-12 KTS
AND BECOMING GUSTY BY LATE MORNING. COLD FRONT WILL PUSH THROUGH
THIS AFTERNOON/EVENING...WITH A GRADUAL DECREASE IN CLOUD COVER
AND SUBSIDING WINDS.
JAB
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...FLASH FLOOD WATCH UNTIL 1 PM CDT THIS AFTERNOON FOR CLAY-
CRAIGHEAD-CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-
MISSISSIPPI-PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS.
MO...FLASH FLOOD WATCH UNTIL 1 PM CDT THIS AFTERNOON FOR DUNKLIN-
PEMISCOT.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
618 AM CDT MON MAY 11 2015
.DISCUSSION...
UPDATED FOR 12Z AVIATION DISCUSSION.
&&
.PREV DISCUSSION... /ISSUED 403 AM CDT MON MAY 11 2015/
DISCUSSION...
CURRENTLY...AN UPPER LOW IS CENTERED OVER THE NORTHERN PLAINS
MOVING NORTHEAST. MEANWHILE A MID LEVEL SHORTWAVE IS MOVING
ACROSS THE SOUTHERN PLAINS AND INTO THE LOWER MISSISSIPPI VALLEY.
THIS FEATURE HAS IGNITED AN AREA SHOWERS AND THUNDERSTORMS ACROSS
ARKANSAS INTO THE ARKLATEX REGION. A LEADING EDGE LINE OF SHOWERS
AND THUNDERSTORMS HAS MOVED INTO NORTHEAST ARKANSAS WHERE LOCALLY
HEAVY RAIN IS OCCURRING. RAIN RATES OF OVER 1 INCH PER HOUR HAVE
BEEN NOTED ACROSS RANDOLPH AND LAWRENCE COUNTIES. ELSW ACROSS THE
MIDSOUTH CLOUDS ARE INCREASING AND TEMPS ARE MILD...IN THE UPPER
60S AND LOWER 70S WITH A LIGHT SOUTH WIND.
TODAY...THIS LINE OF SHOWERS AND THUNDERSTORMS WILL PUSH ACROSS
THE MIDSOUTH THIS MORNING. GOOD UPPER LEVEL SUPPORT WILL HELP
MAINTAIN THE SHOWERS AND THUNDERSTORMS THROUGH ABOUT MID MORNING
AS THEY CROSS EASTERN ARKANSAS...THE MISSOURI BOOTHEEL AND THE
MISSISSIPPI RIVER. STRONG LOW LEVEL MOISTURE TRANSPORT INTO THE
DELTA REGION WILL HELP PRODUCE LOCALLY HEAVY RAINFALL...ESPECIALLY
WEST OF THE MISSISSIPPI RIVER WHERE 1 TO 2 INCHES COULD FALL WITH
LOCALLY HIGHER AMOUNTS. A FLASH FLOOD WATCH REMAIN IN EFFECT UNTIL
NOON WEST OF THE RIVER. MLCAPE VALUES ARE ABOUT 500 J/KG AHEAD OF
THE LINE OF THUNDERSTORMS ACROSS THE DELTA AND BULK SHEAR VALUES
ARE GREATER THAN 40 KTS. AS A RESULT A FEW STORMS COULD BE STRONG
TO SEVERE...MAINLY WEST OF THE MISSISSIPPI RIVER THROUGH ABOUT MID
MORNING. DAMAGING WIND IS THE MAIN THREAT.
AS THE LINE HEADS EAST OF THE MISSISSIPPI RIVER IT WILL WEAKEN AS
THE BETTER UPPER SUPPORT LIFTS NORTHEAST. THE LATEST HRRR DEPICTS
THE REMNANTS OF THE LINE REACHING THE TN RIVER BY ABOUT 18Z.
THERE IS THE QUESTION OF REDEVELOPMENT ALONG THE COLD FRONT AS IT
MOVES INTO THE AREA LATER TODAY AND THIS EVENING. ATTM IT LOOKS
LIKE REDEVELOPMENT WILL BE RATHER MEAGER. FIRST THE COLD FRONT IS
WEAKENING AS IT MOVES INTO THE REGION AND CONVERGENCE ALONG THE
FRONT IS WEAK. ALSO EXPECT A GOOD DEAL OF STRATIFORM RAIN BEHIND
THE INITIAL LINE OF THUNDERSTORMS THAT WILL LAST MUCH OF THE
MORNING. THIS WILL SERVE TO STABILIZE THE AIRMASS AND REALLY DO
NOT SEE IT RECOVERING ENOUGH TO PROMOTE DEVELOPMENT LATER THIS
AFTERNOON INTO THE EVENING. LASTLY MID LEVEL HEIGHTS START TO
RISE. THIS SCENARIO JUST DOES NOT LOOK FAVORABLE FOR
REDEVELOPMENT AND THE LATEST HRRR CORROBORATES THAT.
THE AREA WILL START TO DRY OUT FROM THE NORTHWEST THIS AFTERNOON.
TONIGHT...LEFT SOME LINGERING SHOWERS AND THUNDERSTORMS SOUTH OF
I-40 FOR THE EVENING AS THE WEAK COLD FRONT PUSHES THROUGH. OTRW
SKIES WILL BE CLEARING OVERNIGHT AS SURFACE HIGH PRESSURE STARTS
TO BUILD IN. LOWS WILL DROP INTO THE 50S NORTH TO LOWER 60S
SOUTH.
TUESDAY AND WEDNESDAY...THESE LOOK LIKE SOME VERY NICE DAYS WITH
LOW HUMIDITY AND PLEASANT TEMPS AS HIGH PRESSURE PREVAILS. HIGHS
WILL BE IN THE 70S. LOWS WEDNESDAY MORNING COULD DIP INTO THE
UPPER 40S IN THE COOLER SPOTS.
THURSDAY THROUGH SUNDAY...FRONT WILL LIFT BACK NORTH AS WARM
FRONT AND THE HUMIDITY LEVELS WILL INCREASE LATER IN THE WEEK. THE
UPPER FLOW WILL TRANSITION BACK TO SOUTHWEST FLOW WITH CHANCES
FOR SHOWERS AND THUNDERSTORMS AS DISTURBANCES MOVE THROUGH ALOFT.
HIGH TEMPS WILL BE IN THE LOWER TO MID 80S BY THE END OF THE WEEK
WITH LOWS IN THE 60S.
SJM
&&
.AVIATION...
12Z TAFS
LINE OF TSTMS WILL ADVANCE THROUGH THE TAF SITES EARLY...WITH TUP
BEING LEAST AFFECTED. EXPECT IFR/MVFR CONDITIONS WITHIN THE
HEAVIEST ACTIVITY AND VARIABLE WIND GUSTS. OUTSIDE OF STORMS
WEATHER WILL BE VFR WITH SOUTHWEST WINDS INCREASING TO 10-12 KTS
AND BECOMING GUSTY BY LATE MORNING. COLD FRONT WILL PUSH THROUGH
THIS AFTERNOON/EVENING...WITH A GRADUAL DECREASE IN CLOUD COVER
AND SUBSIDING WINDS.
JAB
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...FLASH FLOOD WATCH UNTIL 1 PM CDT THIS AFTERNOON FOR CLAY-
CRAIGHEAD-CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-
MISSISSIPPI-PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS.
MO...FLASH FLOOD WATCH UNTIL 1 PM CDT THIS AFTERNOON FOR DUNKLIN-
PEMISCOT.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
403 AM CDT MON MAY 11 2015
.DISCUSSION...
CURRENTLY...AN UPPER LOW IS CENTERED OVER THE NORTHERN PLAINS
MOVING NORTHEAST. MEANWHILE A MID LEVEL SHORTWAVE IS MOVING
ACROSS THE SOUTHERN PLAINS AND INTO THE LOWER MISSISSIPPI VALLEY.
THIS FEATURE HAS IGNITED AN AREA SHOWERS AND THUNDERSTORMS ACROSS
ARKANSAS INTO THE ARKLATEX REGION. A LEADING EDGE LINE OF SHOWERS
AND THUNDERSTORMS HAS MOVED INTO NORTHEAST ARKANSAS WHERE LOCALLY
HEAVY RAIN IS OCCURRING. RAIN RATES OF OVER 1 INCH PER HOUR HAVE
BEEN NOTED ACROSS RANDOLPH AND LAWRENCE COUNTIES. ELSW ACROSS THE
MIDSOUTH CLOUDS ARE INCREASING AND TEMPS ARE MILD...IN THE UPPER
60S AND LOWER 70S WITH A LIGHT SOUTH WIND.
TODAY...THIS LINE OF SHOWERS AND THUNDERSTORMS WILL PUSH ACROSS
THE MIDSOUTH THIS MORNING. GOOD UPPER LEVEL SUPPORT WILL HELP
MAINTAIN THE SHOWERS AND THUNDERSTORMS THROUGH ABOUT MID MORNING
AS THEY CROSS EASTERN ARKANSAS...THE MISSOURI BOOTHEEL AND THE
MISSISSIPPI RIVER. STRONG LOW LEVEL MOISTURE TRANSPORT INTO THE
DELTA REGION WILL HELP PRODUCE LOCALLY HEAVY RAINFALL...ESPECIALLY
WEST OF THE MISSISSIPPI RIVER WHERE 1 TO 2 INCHES COULD FALL WITH
LOCALLY HIGHER AMOUNTS. A FLASH FLOOD WATCH REMAIN IN EFFECT UNTIL
NOON WEST OF THE RIVER. MLCAPE VALUES ARE ABOUT 500 J/KG AHEAD OF
THE LINE OF THUNDERSTORMS ACROSS THE DELTA AND BULK SHEAR VALUES
ARE GREATER THAN 40 KTS. AS A RESULT A FEW STORMS COULD BE STRONG
TO SEVERE...MAINLY WEST OF THE MISSISSIPPI RIVER THROUGH ABOUT MID
MORNING. DAMAGING WIND IS THE MAIN THREAT.
AS THE LINE HEADS EAST OF THE MISSISSIPPI RIVER IT WILL WEAKEN AS
THE BETTER UPPER SUPPORT LIFTS NORTHEAST. THE LATEST HRRR DEPICTS
THE REMNANTS OF THE LINE REACHING THE TN RIVER BY ABOUT 18Z.
THERE IS THE QUESTION OF REDEVELOPMENT ALONG THE COLD FRONT AS IT
MOVES INTO THE AREA LATER TODAY AND THIS EVENING. ATTM IT LOOKS
LIKE REDEVELOPMENT WILL BE RATHER MEAGER. FIRST THE COLD FRONT IS
WEAKENING AS IT MOVES INTO THE REGION AND CONVERGENCE ALONG THE
FRONT IS WEAK. ALSO EXPECT A GOOD DEAL OF STRATIFORM RAIN BEHIND
THE INITIAL LINE OF THUNDERSTORMS THAT WILL LAST MUCH OF THE
MORNING. THIS WILL SERVE TO STABILIZE THE AIRMASS AND REALLY DO
NOT SEE IT RECOVERING ENOUGH TO PROMOTE DEVELOPMENT LATER THIS
AFTERNOON INTO THE EVENING. LASTLY MID LEVEL HEIGHTS START TO
RISE. THIS SCENARIO JUST DOES NOT LOOK FAVORABLE FOR
REDEVELOPMENT AND THE LATEST HRRR CORROBORATES THAT.
THE AREA WILL START TO DRY OUT FROM THE NORTHWEST THIS AFTERNOON.
TONIGHT...LEFT SOME LINGERING SHOWERS AND THUNDERSTORMS SOUTH OF
I-40 FOR THE EVENING AS THE WEAK COLD FRONT PUSHES THROUGH. OTRW
SKIES WILL BE CLEARING OVERNIGHT AS SURFACE HIGH PRESSURE STARTS
TO BUILD IN. LOWS WILL DROP INTO THE 50S NORTH TO LOWER 60S
SOUTH.
TUESDAY AND WEDNESDAY...THESE LOOK LIKE SOME VERY NICE DAYS WITH
LOW HUMIDITY AND PLEASANT TEMPS AS HIGH PRESSURE PREVAILS. HIGHS
WILL BE IN THE 70S. LOWS WEDNESDAY MORNING COULD DIP INTO THE
UPPER 40S IN THE COOLER SPOTS.
THURSDAY THROUGH SUNDAY...FRONT WILL LIFT BACK NORTH AS WARM
FRONT AND THE HUMIDITY LEVELS WILL INCREASE LATER IN THE WEEK. THE
UPPER FLOW WILL TRANSITION BACK TO SOUTHWEST FLOW WITH CHANCES
FOR SHOWERS AND THUNDERSTORMS AS DISTURBANCES MOVE THROUGH ALOFT.
HIGH TEMPS WILL BE IN THE LOWER TO MID 80S BY THE END OF THE WEEK
WITH LOWS IN THE 60S.
SJM
&&
.AVIATION...
06Z TAFS
MAIN CORRIDOR OF TSRA WILL BEGIN AFFECTING THE JBR OVER THE NEXT
SEVERAL HOURS...AND ADVANCE EASTWARD TOWARD MEM AFTER 12Z. TSRA
WILL BECOME MORE LINEAR AND PERHAPS BETTER ORGANIZED ALONG AN
ADVANCING COLD FRONT. LATEST 00Z GUIDANCE SHOWS THE FRONTAL TIMING
MAY BE AN HOUR OR TWO QUICKER THAN EARLIER FORECAST...WITH TSRA
CHANCES AT MEM ENDING AS EARLY AS 18Z.
CLEAR SKIES AND LIGHT WINDS FOR THE LATE MONDAY EVENING ARRIVAL
PUSH.
PWB
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...FLASH FLOOD WATCH UNTIL 1 PM CDT THIS AFTERNOON FOR CLAY-
CRAIGHEAD-CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-
MISSISSIPPI-PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS.
MO...FLASH FLOOD WATCH UNTIL 1 PM CDT THIS AFTERNOON FOR DUNKLIN-
PEMISCOT.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
1231 PM CDT MON MAY 11 2015
.DISCUSSION...SEE 18Z AVIATION DISCUSSION.
&&
.AVIATION...WILL HAVE CONVECTION IN THE 24 HOUR TERMINALS...AND DO
THE BEST POSSIBLE BASED ON THE 4KM MODELS WHICH ARE PRETTY MUCH
SHOWING RAIN IN FOR THE AREA OVER THE NEXT SEVERAL HOURS. AM
BETTING THAT THERE WILL BE SOME ORGANIZED CONVECTION DEVELOPING BY
EARLY EVENING OVER THE WESTERN PORTIONS OF THE CWFA...THEN SPREAD
EAST. THIS MAIN CONVECTIVE LINE FORECAST WILL PROVIDE THE
STRONGEST STORMS THIS EVENING UNTIL ABOUT 12/07Z OR SO...BUT THEN
WILL HAVE AT LEAST VCTS AND/OR VCSH IN THE REMAINDER OF THE
FORECAST (WITH -TSRA AOB 12Z). CONVECTION FIRING UP AS THIS IS
BEING WRITTEN...SO WILL HAVE VCSH/VCTS AND TEMPOS THROUGH 11/24Z
FOR ALL TERMINALS...WITH GENERALLY VFR CONDITIONS OUTSIDE OF
CONVECTION. THEN MAIN CONVECTION WILL BEGIN AT KLRD SOMETIME
BETWEEN 22Z AND 02Z...THEN THROUGH THE EASTERN TERMINALS SOMETIME
BETWEEN 02Z AND 07Z (HERE WILL HAVE TEMPOS WITH STRONG WIND
GUSTS). AFTER THAT...WILL CONTINUE WITH -TSRA CATEGORICAL (COULD
HAVE STRONGER STORMS TOO AFTER 07Z BUT HAVE TO KEEP IT
SHORT)...THEN VCSH AT KALI AND KCRP IN THE MORNING WITH SHRA AT
KVCT AND TSRA AT KLRD...THE LATTER EXPECTED DUE TO WEAK OROGRAPHIC
FLOW FROM EASTERLY WINDS. FOR THE MOST PART...WINDS WILL BE
EASTERLY AFTER 12/00Z AND LESS THAN 11 KNOTS OUT OF THUNDER. WITH
THIS PATTERN...CANNOT NAIL TIMING OF CONVECTION AND/OR STRONGEST
STORMS SO THERE LIKELY WILL BE UPDATES TO THE TERMINALS FROM TIME
TO TIME.
&&
.PREV DISCUSSION... /ISSUED 947 AM CDT MON MAY 11 2015/
DISCUSSION...GFE FORECAST MONITOR SHOWING THINGS ARE FINE WITH
RESPECT TO TEMPS/WINDS AND CLOUDS. CONCERNING RAIN CHANCES...SOME
SPOTTY SHOWERS STARTING TO SHOW UP MAINLY OVER THE NORTHERN AREAS
WHERE SURFACE CONVERGENCE IS LOCATED AND CAP IS ERODING FAST.
OVERALL...FORECAST LOOKS GOOD. BASED ON 4 KM MODELS AND
APPROACHING CONVECTION SEEPING SLOWLY SOUTHWARD...WILL MENTION
SEVERE FOR THIS AFTERNOON OVER THE WESTERN AREAS (AND MAY INCLUDE
REMAINDER OF NORTHERN AREAS IF DIFFERENT TRENDS DEVELOP)...BUT
THINK MAIN CONCERN WILL BE WESTERN AREAS. ALSO WILL MENTION HEAVY
RAINFALL OVER THE NORTHERN AREAS THIS AFTERNOON AND ALL AREAS
TONIGHT. CONCERNING RIP CURRENT RISK...IT IS STARTING TO GO DOWN
BUT IT WAS CLOSE THIS MORNING. BASED ON OBSERVATIONS FROM
BOY020...SWELLS HAVE FALLEN TO 4 FEET OR LESS (AND TREND IS
FALLING)...WITH PERIODS STILL 7 TO 8 FEET. MODERATE WILL DO.
TIDES ARE STILL WELL BELOW 2 FEET...WITH MOST BELOW 1.5 FEET AND
HEIGHTS OF HIGH TIDES ARE SLIGHTLY LOWER. MARINE FORECAST IS OK.
MINOR UPDATES OF PRODUCTS WILL BE OUT SHORTLY.
PREV DISCUSSION... /ISSUED 636 AM CDT MON MAY 11 2015/
DISCUSSION...UPDATED FOR 12Z AVIATION.
AVIATION...LOW END VFR AND MVFR CEILINGS CAN BE EXPECTED THROUGH
MUCH OF THE PERIOD. CHANCES FOR SHOWERS AND STORMS WILL INCREASE
AS SLOW MOVING COLD FRONT APPROACHES SOUTH TEXAS. LATEST HRRR HAS
SLOWED DOWN ONSET OF CONVECTION SO WILL KEEP VCTS REMARKS FOR
NOW. IF THUNDERSTORMS DIRECTLY IMPACT THE TERMINALS...HEAVY
RAIN...BRIEF GUSTY WINDS AND REDUCED VSBYS WILL BE LIKELY. WINDS
THROUGH THE PERIOD WILL BE PREDOMINANTLY OUT OF THE E AND ESE WITH
SPEEDS LESS THAN 15 KNOTS.
PREV DISCUSSION... /ISSUED 427 AM CDT MON MAY 11 2015/
SHORT TERM (TODAY THROUGH TUESDAY)...MAIN FOCUS THROUGH THE SHORT
TERM WILL BE THUNDERSTORM CHANCES. UPPER LEVEL TROUGH OVER THE
CENTRAL/SOUTHERN PLAINS WILL LIFT TO THE NORTHEAST INTO THE OHIO
VALLEY AND GREAT LAKES REGION. AT THE SURFACE...SLOW MOVING COLD
FRONT WILL CONTINUE TO APPROACH THE AREA. LOW LEVEL E/SE FLOW WILL
ALLOW DEEP MOISTURE TO REMAIN ACROSS SOUTH TEXAS. MODELS PROG PW
VALUES TO BE BETWEEN 1.8 AND 2.0 INCHES...WHICH IS WELL ABOVE
NORMAL FOR THIS TIME OF YEAR. THESE FACTORS WILL LEAD TO
INCREASING THUNDERSTORM CHANCES THROUGH THE SHORT TERM.
CURRENTLY...A SQUALL LINE IS PUSHING ACROSS EASTERN TEXAS.
ADDITIONAL CONVECTION HAS RECENTLY DEVELOPED OVER THE EDWARDS
PLATEAU INTO THE HILL COUNTRY. LATEST HRRR RUNS HAVE BEEN HINTING
AT THIS AND EVENTUALLY BRING SOME OF THIS ACTIVITY TO THE SE
THROUGH THE MORNING...APPROACHING THE N AND NW SECTIONS BY MIDDAY.
ADDITIONAL CONVECTION WILL THEN BE POSSIBLE LATE THIS AFTERNOON
AND EVENING FROM THE WEST AS UPPER DISTURBANCE IN W/WSW FLOW ALOFT
TRAVERSES THE AREA. WILL HAVE TO CONTINUE TO MONITOR THE
POSSIBILITY OF SOME STRONG TO SEVERE STORMS TODAY. PRIMARY HAZARDS
WOULD BE LARGE HAIL AND DAMAGING WINDS WITH SUFFICIENT
INSTABILITY/SHEAR OVER THE REGION. ALSO INCLUDED A MENTION OF
HEAVY RAIN TONIGHT AS BOUNDARY DRAWS NEAR. WILL NOT ISSUE A FLASH
FLOOD WATCH AT THIS TIME BUT ONE MAY BECOME NECESSARY IN LATER
SHIFTS. UNSETTLED WEATHER WILL PERSIST INTO TUESDAY AS COLD FRONT
AND DEEP MOISTURE REMAINS IN THE VICINITY. POPS ON TUESDAY RANGE
FROM 80 PERCENT ACROSS THE NORTH TO 50 ACROSS THE SOUTH. SLIGHT
RISK OF SEVERE WEATHER WILL EXIST ON TUESDAY AS MODELS STILL
FORECAST UNSTABLE AIRMASS ACROSS SOUTH TEXAS. THE THREAT OF
MODERATE TO HEAVY RAIN WILL CONTINUE INTO TUESDAY AS WELL.
LONG TERM (TUESDAY NIGHT THROUGH SUNDAY)...ACTIVE WET PERIOD
CONTINUES TO BE IN STORE FOR MUCH OF THE WEEK. FRONTAL BOUNDARY WILL
BE TO THE NORTH OF THE AREA BEGINNING THE PERIOD...WITH DEEP
ABUNDANT MOISTURE ACROSS THE REGION. SEVERAL ROUNDS OF SHORTWAVES
WILL MOVE ACROSS THE REGION...PROVIDING UPPER SUPPORT FOR CONVECTION
ACROSS THE REGION THROUGH THE MID WEEK. FRONTAL BOUNDARY DISSIPATES
LATE IN THE WEEK WITH ANOTHER UPPER TROUGH DIGGING INTO THE DESERT
SOUTHWEST. POPS WILL DECREASE ACROSS THE REGION FRIDAY INTO THE
WEEKEND...THOUGH WILL STILL MAINTAIN SLIGHT CHANCE TO LOW END CHANCE
POPS BY THE WEEKEND. STILL ANTICIPATING HIGH QPF POTENTIAL FOR THIS
WEEK...WITH AREAS POSSIBLY RECEIVING RAINFALL AMOUNTS IN EXCESS OF 5
INCHES ACROSS THE NORTHERN BRUSH COUNTRY...TO OVER 2 INCHES POSSIBLE
ALONG THE COASTAL BEND THROUGH THE WEEK.
A GRADUAL WARMING TREND CAN BE EXPECTED FROM MID WEEK ONWARD...WITH
HIGHS IN THE LOW TO MID 80S WEDNESDAY...AND IN THE MID 80S TO LOWER
90S BY THE WEEKEND. LOWS WILL ALSO BE ON THE RISE...GOING FROM THE
LOWER 70S EARLY IN THE WEEK TO THE MID 70S BY THE WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 85 75 82 74 81 / 40 80 60 70 40
VICTORIA 86 72 81 71 81 / 60 80 80 70 50
LAREDO 88 72 84 72 84 / 50 80 70 70 60
ALICE 87 73 83 72 83 / 50 80 60 70 40
ROCKPORT 84 75 80 74 80 / 40 80 60 70 40
COTULLA 86 70 81 69 83 / 60 90 80 70 70
KINGSVILLE 87 74 83 73 83 / 40 80 60 60 40
NAVY CORPUS 83 75 81 75 80 / 40 80 60 60 40
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
GW/86...AVIATION
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
947 AM CDT MON MAY 11 2015
.DISCUSSION...GFE FORECAST MONITOR SHOWING THINGS ARE FINE WITH
RESPECT TO TEMPS/WINDS AND CLOUDS. CONCERNING RAIN CHANCES...SOME
SPOTTY SHOWERS STARTING TO SHOW UP MAINLY OVER THE NORTHERN AREAS
WHERE SURFACE CONVERGENCE IS LOCATED AND CAP IS ERODING FAST.
OVERALL...FORECAST LOOKS GOOD. BASED ON 4 KM MODELS AND
APPROACHING CONVECTION SEEPING SLOWLY SOUTHWARD...WILL MENTION
SEVERE FOR THIS AFTERNOON OVER THE WESTERN AREAS (AND MAY INCLUDE
REMAINDER OF NORTHERN AREAS IF DIFFERENT TRENDS DEVELOP)...BUT
THINK MAIN CONCERN WILL BE WESTERN AREAS. ALSO WILL MENTION HEAVY
RAINFALL OVER THE NORTHERN AREAS THIS AFTERNOON AND ALL AREAS
TONIGHT. CONCERNING RIP CURRENT RISK...IT IS STARTING TO GO DOWN
BUT IT WAS CLOSE THIS MORNING. BASED ON OBSERVATIONS FROM
BOY020...SWELLS HAVE FALLEN TO 4 FEET OR LESS (AND TREND IS
FALLING)...WITH PERIODS STILL 7 TO 8 FEET. MODERATE WILL DO.
TIDES ARE STILL WELL BELOW 2 FEET...WITH MOST BELOW 1.5 FEET AND
HEIGHTS OF HIGH TIDES ARE SLIGHTLY LOWER. MARINE FORECAST IS OK.
MINOR UPDATES OF PRODUCTS WILL BE OUT SHORTLY.
&&
.PREV DISCUSSION... /ISSUED 636 AM CDT MON MAY 11 2015/
DISCUSSION...UPDATED FOR 12Z AVIATION.
AVIATION...LOW END VFR AND MVFR CEILINGS CAN BE EXPECTED THROUGH
MUCH OF THE PERIOD. CHANCES FOR SHOWERS AND STORMS WILL INCREASE
AS SLOW MOVING COLD FRONT APPROACHES SOUTH TEXAS. LATEST HRRR HAS
SLOWED DOWN ONSET OF CONVECTION SO WILL KEEP VCTS REMARKS FOR
NOW. IF THUNDERSTORMS DIRECTLY IMPACT THE TERMINALS...HEAVY
RAIN...BRIEF GUSTY WINDS AND REDUCED VSBYS WILL BE LIKELY. WINDS
THROUGH THE PERIOD WILL BE PREDOMINANTLY OUT OF THE E AND ESE WITH
SPEEDS LESS THAN 15 KNOTS.
PREV DISCUSSION... /ISSUED 427 AM CDT MON MAY 11 2015/
SHORT TERM (TODAY THROUGH TUESDAY)...MAIN FOCUS THROUGH THE SHORT
TERM WILL BE THUNDERSTORM CHANCES. UPPER LEVEL TROUGH OVER THE
CENTRAL/SOUTHERN PLAINS WILL LIFT TO THE NORTHEAST INTO THE OHIO
VALLEY AND GREAT LAKES REGION. AT THE SURFACE...SLOW MOVING COLD
FRONT WILL CONTINUE TO APPROACH THE AREA. LOW LEVEL E/SE FLOW WILL
ALLOW DEEP MOISTURE TO REMAIN ACROSS SOUTH TEXAS. MODELS PROG PW
VALUES TO BE BETWEEN 1.8 AND 2.0 INCHES...WHICH IS WELL ABOVE
NORMAL FOR THIS TIME OF YEAR. THESE FACTORS WILL LEAD TO
INCREASING THUNDERSTORM CHANCES THROUGH THE SHORT TERM.
CURRENTLY...A SQUALL LINE IS PUSHING ACROSS EASTERN TEXAS.
ADDITIONAL CONVECTION HAS RECENTLY DEVELOPED OVER THE EDWARDS
PLATEAU INTO THE HILL COUNTRY. LATEST HRRR RUNS HAVE BEEN HINTING
AT THIS AND EVENTUALLY BRING SOME OF THIS ACTIVITY TO THE SE
THROUGH THE MORNING...APPROACHING THE N AND NW SECTIONS BY MIDDAY.
ADDITIONAL CONVECTION WILL THEN BE POSSIBLE LATE THIS AFTERNOON
AND EVENING FROM THE WEST AS UPPER DISTURBANCE IN W/WSW FLOW ALOFT
TRAVERSES THE AREA. WILL HAVE TO CONTINUE TO MONITOR THE
POSSIBILITY OF SOME STRONG TO SEVERE STORMS TODAY. PRIMARY HAZARDS
WOULD BE LARGE HAIL AND DAMAGING WINDS WITH SUFFICIENT
INSTABILITY/SHEAR OVER THE REGION. ALSO INCLUDED A MENTION OF
HEAVY RAIN TONIGHT AS BOUNDARY DRAWS NEAR. WILL NOT ISSUE A FLASH
FLOOD WATCH AT THIS TIME BUT ONE MAY BECOME NECESSARY IN LATER
SHIFTS. UNSETTLED WEATHER WILL PERSIST INTO TUESDAY AS COLD FRONT
AND DEEP MOISTURE REMAINS IN THE VICINITY. POPS ON TUESDAY RANGE
FROM 80 PERCENT ACROSS THE NORTH TO 50 ACROSS THE SOUTH. SLIGHT
RISK OF SEVERE WEATHER WILL EXIST ON TUESDAY AS MODELS STILL
FORECAST UNSTABLE AIRMASS ACROSS SOUTH TEXAS. THE THREAT OF
MODERATE TO HEAVY RAIN WILL CONTINUE INTO TUESDAY AS WELL.
LONG TERM (TUESDAY NIGHT THROUGH SUNDAY)...ACTIVE WET PERIOD
CONTINUES TO BE IN STORE FOR MUCH OF THE WEEK. FRONTAL BOUNDARY WILL
BE TO THE NORTH OF THE AREA BEGINNING THE PERIOD...WITH DEEP
ABUNDANT MOISTURE ACROSS THE REGION. SEVERAL ROUNDS OF SHORTWAVES
WILL MOVE ACROSS THE REGION...PROVIDING UPPER SUPPORT FOR CONVECTION
ACROSS THE REGION THROUGH THE MID WEEK. FRONTAL BOUNDARY DISSIPATES
LATE IN THE WEEK WITH ANOTHER UPPER TROUGH DIGGING INTO THE DESERT
SOUTHWEST. POPS WILL DECREASE ACROSS THE REGION FRIDAY INTO THE
WEEKEND...THOUGH WILL STILL MAINTAIN SLIGHT CHANCE TO LOW END CHANCE
POPS BY THE WEEKEND. STILL ANTICIPATING HIGH QPF POTENTIAL FOR THIS
WEEK...WITH AREAS POSSIBLY RECEIVING RAINFALL AMOUNTS IN EXCESS OF 5
INCHES ACROSS THE NORTHERN BRUSH COUNTRY...TO OVER 2 INCHES POSSIBLE
ALONG THE COASTAL BEND THROUGH THE WEEK.
A GRADUAL WARMING TREND CAN BE EXPECTED FROM MID WEEK ONWARD...WITH
HIGHS IN THE LOW TO MID 80S WEDNESDAY...AND IN THE MID 80S TO LOWER
90S BY THE WEEKEND. LOWS WILL ALSO BE ON THE RISE...GOING FROM THE
LOWER 70S EARLY IN THE WEEK TO THE MID 70S BY THE WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 85 75 82 74 81 / 40 80 60 70 40
VICTORIA 86 72 81 71 81 / 60 80 80 70 50
LAREDO 88 72 84 72 84 / 50 80 70 70 60
ALICE 87 73 83 72 83 / 50 80 60 70 40
ROCKPORT 84 75 80 74 80 / 40 80 60 70 40
COTULLA 86 70 81 69 83 / 60 90 80 70 70
KINGSVILLE 87 74 83 73 83 / 40 80 60 60 40
NAVY CORPUS 83 75 81 75 80 / 40 80 60 60 40
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
GW/86...SHORT TERM
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
636 AM CDT MON MAY 11 2015
.DISCUSSION...UPDATED FOR 12Z AVIATION.
&&
.AVIATION...LOW END VFR AND MVFR CEILINGS CAN BE EXPECTED THROUGH
MUCH OF THE PERIOD. CHANCES FOR SHOWERS AND STORMS WILL INCREASE
AS SLOW MOVING COLD FRONT APPROACHES SOUTH TEXAS. LATEST HRRR HAS
SLOWED DOWN ONSET OF CONVECTION SO WILL KEEP VCTS REMARKS FOR
NOW. IF THUNDERSTORMS DIRECTLY IMPACT THE TERMINALS...HEAVY
RAIN...BRIEF GUSTY WINDS AND REDUCED VSBYS WILL BE LIKELY. WINDS
THROUGH THE PERIOD WILL BE PREDOMINANTLY OUT OF THE E AND ESE WITH
SPEEDS LESS THAN 15 KNOTS.
&&
.PREV DISCUSSION... /ISSUED 427 AM CDT MON MAY 11 2015/
SHORT TERM (TODAY THROUGH TUESDAY)...MAIN FOCUS THROUGH THE SHORT
TERM WILL BE THUNDERSTORM CHANCES. UPPER LEVEL TROUGH OVER THE
CENTRAL/SOUTHERN PLAINS WILL LIFT TO THE NORTHEAST INTO THE OHIO
VALLEY AND GREAT LAKES REGION. AT THE SURFACE...SLOW MOVING COLD
FRONT WILL CONTINUE TO APPROACH THE AREA. LOW LEVEL E/SE FLOW WILL
ALLOW DEEP MOISTURE TO REMAIN ACROSS SOUTH TEXAS. MODELS PROG PW
VALUES TO BE BETWEEN 1.8 AND 2.0 INCHES...WHICH IS WELL ABOVE
NORMAL FOR THIS TIME OF YEAR. THESE FACTORS WILL LEAD TO
INCREASING THUNDERSTORM CHANCES THROUGH THE SHORT TERM.
CURRENTLY...A SQUALL LINE IS PUSHING ACROSS EASTERN TEXAS.
ADDITIONAL CONVECTION HAS RECENTLY DEVELOPED OVER THE EDWARDS
PLATEAU INTO THE HILL COUNTRY. LATEST HRRR RUNS HAVE BEEN HINTING
AT THIS AND EVENTUALLY BRING SOME OF THIS ACTIVITY TO THE SE
THROUGH THE MORNING...APPROACHING THE N AND NW SECTIONS BY MIDDAY.
ADDITIONAL CONVECTION WILL THEN BE POSSIBLE LATE THIS AFTERNOON
AND EVENING FROM THE WEST AS UPPER DISTURBANCE IN W/WSW FLOW ALOFT
TRAVERSES THE AREA. WILL HAVE TO CONTINUE TO MONITOR THE
POSSIBILITY OF SOME STRONG TO SEVERE STORMS TODAY. PRIMARY HAZARDS
WOULD BE LARGE HAIL AND DAMAGING WINDS WITH SUFFICIENT
INSTABILITY/SHEAR OVER THE REGION. ALSO INCLUDED A MENTION OF
HEAVY RAIN TONIGHT AS BOUNDARY DRAWS NEAR. WILL NOT ISSUE A FLASH
FLOOD WATCH AT THIS TIME BUT ONE MAY BECOME NECESSARY IN LATER
SHIFTS. UNSETTLED WEATHER WILL PERSIST INTO TUESDAY AS COLD FRONT
AND DEEP MOISTURE REMAINS IN THE VICINITY. POPS ON TUESDAY RANGE
FROM 80 PERCENT ACROSS THE NORTH TO 50 ACROSS THE SOUTH. SLIGHT
RISK OF SEVERE WEATHER WILL EXIST ON TUESDAY AS MODELS STILL
FORECAST UNSTABLE AIRMASS ACROSS SOUTH TEXAS. THE THREAT OF
MODERATE TO HEAVY RAIN WILL CONTINUE INTO TUESDAY AS WELL.
LONG TERM (TUESDAY NIGHT THROUGH SUNDAY)...ACTIVE WET PERIOD
CONTINUES TO BE IN STORE FOR MUCH OF THE WEEK. FRONTAL BOUNDARY WILL
BE TO THE NORTH OF THE AREA BEGINNING THE PERIOD...WITH DEEP
ABUNDANT MOISTURE ACROSS THE REGION. SEVERAL ROUNDS OF SHORTWAVES
WILL MOVE ACROSS THE REGION...PROVIDING UPPER SUPPORT FOR CONVECTION
ACROSS THE REGION THROUGH THE MID WEEK. FRONTAL BOUNDARY DISSIPATES
LATE IN THE WEEK WITH ANOTHER UPPER TROUGH DIGGING INTO THE DESERT
SOUTHWEST. POPS WILL DECREASE ACROSS THE REGION FRIDAY INTO THE
WEEKEND...THOUGH WILL STILL MAINTAIN SLIGHT CHANCE TO LOW END CHANCE
POPS BY THE WEEKEND. STILL ANTICIPATING HIGH QPF POTENTIAL FOR THIS
WEEK...WITH AREAS POSSIBLY RECEIVING RAINFALL AMOUNTS IN EXCESS OF 5
INCHES ACROSS THE NORTHERN BRUSH COUNTRY...TO OVER 2 INCHES POSSIBLE
ALONG THE COASTAL BEND THROUGH THE WEEK.
A GRADUAL WARMING TREND CAN BE EXPECTED FROM MID WEEK ONWARD...WITH
HIGHS IN THE LOW TO MID 80S WEDNESDAY...AND IN THE MID 80S TO LOWER
90S BY THE WEEKEND. LOWS WILL ALSO BE ON THE RISE...GOING FROM THE
LOWER 70S EARLY IN THE WEEK TO THE MID 70S BY THE WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 85 75 82 74 81 / 40 80 60 70 40
VICTORIA 86 72 81 71 81 / 60 80 80 70 50
LAREDO 88 72 84 72 84 / 50 80 70 70 60
ALICE 87 73 83 72 83 / 50 80 60 70 40
ROCKPORT 84 75 80 74 80 / 40 80 60 70 40
COTULLA 86 70 81 69 83 / 60 90 80 70 70
KINGSVILLE 87 74 83 73 83 / 40 80 60 60 40
NAVY CORPUS 83 75 81 75 80 / 40 80 60 60 40
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
TB/78...AVIATION
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
427 AM CDT MON MAY 11 2015
.SHORT TERM (TODAY THROUGH TUESDAY)...MAIN FOCUS THROUGH THE SHORT
TERM WILL BE THUNDERSTORM CHANCES. UPPER LEVEL TROUGH OVER THE
CENTRAL/SOUTHERN PLAINS WILL LIFT TO THE NORTHEAST INTO THE OHIO
VALLEY AND GREAT LAKES REGION. AT THE SURFACE...SLOW MOVING COLD
FRONT WILL CONTINUE TO APPROACH THE AREA. LOW LEVEL E/SE FLOW WILL
ALLOW DEEP MOISTURE TO REMAIN ACROSS SOUTH TEXAS. MODELS PROG PW
VALUES TO BE BETWEEN 1.8 AND 2.0 INCHES...WHICH IS WELL ABOVE
NORMAL FOR THIS TIME OF YEAR. THESE FACTORS WILL LEAD TO
INCREASING THUNDERSTORM CHANCES THROUGH THE SHORT TERM.
CURRENTLY...A SQUALL LINE IS PUSHING ACROSS EASTERN TEXAS.
ADDITIONAL CONVECTION HAS RECENTLY DEVELOPED OVER THE EDWARDS
PLATEAU INTO THE HILL COUNTRY. LATEST HRRR RUNS HAVE BEEN HINTING
AT THIS AND EVENTUALLY BRING SOME OF THIS ACTIVITY TO THE SE
THROUGH THE MORNING...APPROACHING THE N AND NW SECTIONS BY MIDDAY.
ADDITIONAL CONVECTION WILL THEN BE POSSIBLE LATE THIS AFTERNOON
AND EVENING FROM THE WEST AS UPPER DISTURBANCE IN W/WSW FLOW ALOFT
TRAVERSES THE AREA. WILL HAVE TO CONTINUE TO MONITOR THE
POSSIBILITY OF SOME STRONG TO SEVERE STORMS TODAY. PRIMARY HAZARDS
WOULD BE LARGE HAIL AND DAMAGING WINDS WITH SUFFICIENT
INSTABILITY/SHEAR OVER THE REGION. ALSO INCLUDED A MENTION OF
HEAVY RAIN TONIGHT AS BOUNDARY DRAWS NEAR. WILL NOT ISSUE A FLASH
FLOOD WATCH AT THIS TIME BUT ONE MAY BECOME NECESSARY IN LATER
SHIFTS. UNSETTLED WEATHER WILL PERSIST INTO TUESDAY AS COLD FRONT
AND DEEP MOISTURE REMAINS IN THE VICINITY. POPS ON TUESDAY RANGE
FROM 80 PERCENT ACROSS THE NORTH TO 50 ACROSS THE SOUTH. SLIGHT
RISK OF SEVERE WEATHER WILL EXIST ON TUESDAY AS MODELS STILL
FORECAST UNSTABLE AIRMASS ACROSS SOUTH TEXAS. THE THREAT OF
MODERATE TO HEAVY RAIN WILL CONTINUE INTO TUESDAY AS WELL.
&&
.LONG TERM (TUESDAY NIGHT THROUGH SUNDAY)...ACTIVE WET PERIOD
CONTINUES TO BE IN STORE FOR MUCH OF THE WEEK. FRONTAL BOUNDARY WILL
BE TO THE NORTH OF THE AREA BEGINNING THE PERIOD...WITH DEEP
ABUNDANT MOISTURE ACROSS THE REGION. SEVERAL ROUNDS OF SHORTWAVES
WILL MOVE ACROSS THE REGION...PROVIDING UPPER SUPPORT FOR CONVECTION
ACROSS THE REGION THROUGH THE MID WEEK. FRONTAL BOUNDARY DISSIPATES
LATE IN THE WEEK WITH ANOTHER UPPER TROUGH DIGGING INTO THE DESERT
SOUTHWEST. POPS WILL DECREASE ACROSS THE REGION FRIDAY INTO THE
WEEKEND...THOUGH WILL STILL MAINTAIN SLIGHT CHANCE TO LOW END CHANCE
POPS BY THE WEEKEND. STILL ANTICIPATING HIGH QPF POTENTIAL FOR THIS
WEEK...WITH AREAS POSSIBLY RECEIVING RAINFALL AMOUNTS IN EXCESS OF 5
INCHES ACROSS THE NORTHERN BRUSH COUNTRY...TO OVER 2 INCHES POSSIBLE
ALONG THE COASTAL BEND THROUGH THE WEEK.
A GRADUAL WARMING TREND CAN BE EXPECTED FROM MID WEEK ONWARD...WITH
HIGHS IN THE LOW TO MID 80S WEDNESDAY...AND IN THE MID 80S TO LOWER
90S BY THE WEEKEND. LOWS WILL ALSO BE ON THE RISE...GOING FROM THE
LOWER 70S EARLY IN THE WEEK TO THE MID 70S BY THE WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 85 75 82 74 81 / 40 80 60 70 40
VICTORIA 86 72 81 71 81 / 60 80 80 70 50
LAREDO 88 72 84 72 84 / 50 80 70 70 60
ALICE 87 73 83 72 83 / 50 80 60 70 40
ROCKPORT 84 75 80 74 80 / 40 80 60 70 40
COTULLA 86 70 81 69 83 / 60 90 80 70 70
KINGSVILLE 87 74 83 73 83 / 40 80 60 60 40
NAVY CORPUS 83 75 81 75 80 / 40 80 60 60 40
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...HIGH RIP CURRENT RISK UNTIL 6 AM CDT EARLY THIS MORNING FOR THE
FOLLOWING ZONES: ARANSAS...CALHOUN...KLEBERG...NUECES.
GM...SMALL CRAFT ADVISORY UNTIL 6 AM CDT EARLY THIS MORNING FOR THE
FOLLOWING ZONES: COASTAL WATERS FROM BAFFIN BAY TO PORT
ARANSAS OUT 20 NM...COASTAL WATERS FROM PORT ARANSAS TO
MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM BAFFIN BAY
TO PORT ARANSAS FROM 20 TO 60 NM...WATERS FROM PORT ARANSAS
TO MATAGORDA SHIP CHANNEL FROM 20 TO 60 NM.
&&
$$
TB/78...SHORT TERM
LK/84...LONG TERM
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
737 AM EDT MON MAY 11 2015
.SYNOPSIS...
LOW PRESSURE WAS OVER SOUTH DAKOTA WITH A COLD FRONT TRAILING INTO
NORTHERN TEXAS. THIS FRONT WILL MOVE EAST TODAY AND TONIGHT AND
WILL BE OFF THE COAST BY TUESDAY NIGHT. TROPICAL DEPRESSION ANA
WAS OVER EASTERN NORTH CAROLINA AND WILL WEAKEN AND MOVE
NORTHEAST TO THE MASSACHUSETTS COAST BY TUESDAY MORNING.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 415 AM EDT MONDAY...
WATCHING TWO FEATURES THIS MORNING. TROPICAL DEPRESSION ANA WAS IN
EAST CENTRAL NORTH CAROLINA AND WILL ACCELERATE AND OPEN IN A TROF
BY LATE TONIGHT. A SHORT WAVE ON THE NORTHERN EDGE OF THE SOUTHEAST
UPPER RIDGE WAS MOVING THROUGH THE OHIO VALLEY AND WAS GENERATING
SHOWERS AND ISOLATED THUNDERSTORMS OVER WEST VIRGINIA.
LOCAL WRF MODELS SHOWED A NORTH-SOUTH ORIENTED AXIS OF ISOLATED TO
SCATTERED SHOWERS AND THUNDERSTORMS MOVING INTO THE WESTERN COUNTY
WARNING AREA BEFORE 8AM...THEN WEAKENING LATE THIS MORNING. HAVE
ALIGNED PROBABILITY OF PRECIPITATION THROUGH NOON WITH CURRENT RADAR
TRENDS AND THE LOCAL WRF.
OUTFLOW BOUNDARY CROSSING THROUGH OHIO AND KENTUCKY MAY BECOME THE
FOCUS FOR SHOWERS AND THUNDERSTORMS FARTHER EAST THIS AFTERNOON.
APPEARS BEST WINDOW FOR PRECIPITATION WILL BE WITH THE OUTFLOW OR
PRE-FRONTAL TROF...MAINLY BETWEEN 18Z/2PM AND 03Z/11PM. SOME MODELS
WERE CONFINING SHOWERS AND THUNDERSTORMS TO JUST THE WESTERN COUNTY
WARNING AREA...BUT DON`T SEE WHY THE CHANCE WOULD NOT EXTENDED INTO
THE EASTERN PART OF THE FORECAST AREA ONCE THE WINDS COME AROUND TO
THE SOUTHWEST.
ACTUAL COLD FRONT CROSSES THROUGH THE FORECAST AREA LATE TONIGHT.
HAVE KEPT IN UPSLOPE SHOWERS BEHIND THE FRONT INTO TUESDAY MORNING
FOR SOUTHEAST WEST VIRGINIA.
NO CHANGE IN AIR MASS TODAY OR TONIGHT AHEAD OF THE FRONT. MAXIMUM
TEMPERATURES TODAY WILL STILL BE ABOVE NORMAL WITH ANY DECENT AMOUNT
OF SUN.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 330 AM EDT MONDAY...
BY TUESDAY MORNING...THE REMNANTS OF ANA WILL BE LOCATED OFF THE NEW
JERSEY SHORE AND TRAVEL NORTHEAST TO OFF THE NEW ENGLAND COAST BY
TUESDAY AFTERNOON INTO TUESDAY NIGHT.
THE UPPER LOW WILL CONTINUE TO SHEAR OUT TUESDAY AND SHIFT INTO THE
EASTERN GREAT LAKES/SOUTHEASTERN CANADA. AT THE SURFACE...A COLD
FRONT ATTENDANT TO UPPER TROUGH WILL ADVANCE SOUTHEAST ACROSS THE
REGION...THEN MOVE OFF THE ATLANTIC COAST TUESDAY EVENING/NIGHT.
THE PROXIMITY OF THE BOUNDARY...GOOD THERMODYNAMICS AND
HEATING...SUPPORT THE MENTION OF SCATTERED AFTERNOON SHOWERS AND
THUNDERSTORMS ACROSS THE PIEDMONTS NEAR AND SOUTH OF THE FRONT. THE
DAY TWO CONVECTIVE OUTLOOK HAS PLACE A MARGINAL (5 PERCENT) TO
THE SOUTHEAST OF OUR AREA ACROSS EASTERN NORTH CAROLINA AND
SOUTHEAST VIRGINIA. HIGH TEMPERATURES TUESDAY WILL REMAIN ABOVE
NORMAL WITH READINGS FROM THE MID 60S IN THE NORTHWEST MOUNTAINS
TO THE UPPER 80S IN THE PIEDMONTS. DRIER AIR FROM THE OHIO VALLEY
PUSHES SOUTH ACROSS OUR AREA TUESDAY NIGHT. LOW TEMPERATURES WILL
SEEM CHILLY COMPARED TO RECENT DAYS WITH VALUES FROM LOWER 40S IN
THE NORTHERN MOUNTAINS TO THE MID 50S IN THE SOUTHEAST.
HIGH PRESSURE CONTINUES TO SLIDE EASTWARD WEDNESDAY INTO WEDNESDAY
NIGHT. DRY AIR WILL FILTER INTO THE REGION AT LEAST FOR A COUPLE OF
DAYS...ALLOWING DEWPOINTS TO DROP INTO THE 30S AND 40S ACROSS THE
MOUNTAINS AND 50S ELSEWHERE. HIGH TEMPERATURES WEDNESDAY WILL RANGE
THE UPPER 50S IN THE NORTHWEST MOUNTAINS TO THE UPPER 70S IN THE
PIEDMONTS. UNDER A BUILDING UPPER RIDGE...WEDNESDAY NIGHT LOW
TEMPERATURES WILL DROP INTO THE LOWER 40S IN THE WEST TO LOWER 50S
IN THE EAST.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 400 PM EDT SUNDAY...
THURSDAY SHOULD BE ONE FINAL DRY DAY ACROSS THE REGION WITH RELATIVE
LOW HUMIDITIES AND NEAR NORMAL MAX TEMPS AND NEAR TO SLIGHTLY BELOW
NORMAL MIN TEMPS... 60S AND 70S MOUNTAINS MOUNTAINS TO NEAR 80
PIEDMONT...WITH LOWS IN THE 40S MOUNTAINS AND 50S ELSEWHERE.
FOR FRI AND INTO THE WEEKEND...THE REGION SHIFTS INTO A LARGELY
SUMMERLIKE PATTERN WITH INCREASINGLY OPPRESSIVE LEVELS OF HUMIDITY
AS A SUBTROPICAL RIDGE BUILDS ACROSS THE SOUTHEAST STATES. A
POTENTIALLY SIGNIFICANT OVERRUNNING EVENT WILL PRECEDED THE
TRANSITION FROM THE DRIER CONDITIONS OF THU TO THE SUMMERLIKE
PATTERN EXPECTED BY THE WEEKEND AS THE RETURNING FRONTAL BOUNDARY
COMBINES WITH AN UPPER LEVEL SHORT WAVE AND THE RETURN OF DEEP
GULF MOISTURE. WIDESPREAD RAIN AND A FEW THUNDERSTORMS APPEAR
LIKELY FRIDAY...ESPECIALLY IN THE WEST.
THEREAFTER...ACTIVITY WILL BECOME INCREASINGLY DIURNALLY FOCUSED
WITH AN UPPER RIDGE DEVELOPING OVER THE REGION AS YET ANOTHER
TROUGH FILLS INTO THE SOUTHWEST U.S. HIGH TEMPERATURES IN THE 70S
WEST AND THE 80S EAST WILL RULE THROUGH MUCH OF THE PERIOD WITH
INCREASING HUMIDITY LEVELS.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AS OF 735 AM EDT MONDAY...
FIRST VISIBLE SATELLITE PICTURES THIS MORNING SHOWED PATCHY IFR
TO LIFR SHALLOW FOG IN THE WESTERN VALLEYS. EXPECT KLWB AND KBCB
TO RETURN TO VFR BY 14Z/10AM.
A COLD FRONT WILL CROSS THROUGH THE AREA LATE THIS AFTERNOON INTO
THIS EVENING. AHEAD OF THIS FRONT SHORT RANGE WRF AND HRRR PAST
FEW RUNS HAVE SHOWN SHOWER AND THUNDERSTORM DEVELOPMENT BEGINNING
AROUND 17Z/1PM IN THE MOUNTAINS. LOW LEVEL MOISTURE AND WEST WINDS
WILL BRING MVFR CEILINGS TO KBLF AND KLWB OVERNIGHT. LOW CONFIDENCE
IF CEILINGS WILL BE LOWER THAN MVFR.
A MUCH DRIER AIR MASS COMES INTO THE REGION WITH VFR CONDITIONS
TUESDAY THROUGH THURSDAY. GUSTY NORTHWEST WINDS ARE EXPECTED ON
TUESDAY AND POSSIBLY WEDNESDAY. THE NEXT CHANCE OF SUB VFR WEATHER
AND PRECIPITATION WILL BE ON FRIDAY.
&&
.CLIMATE...
AS OF 425 AM EDT MONDAY...
A FEW MAXIMUM TEMPERATURE RECORDS MAY BE SET TODAY.
HERE ARE THE CURRENT RECORD HIGHS...
ROANOKE 91 IN 1953
LYNCHBURG 94 IN 1896
DANVILLE 94 IN 1953
BLUEFIELD 83 IN 2007
LEWISBURG 82 IN 2007
BLACKSBURG 84 IN 2007
RECORD WARM MINIMUM TEMPERATURES ARE ALSO POSSIBLE.
ROANOKE 64 IN 1991
DANVILLE 68 IN 1963
BLUEFIELD 62 IN 2007
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...KK
LONG TERM...RAB
AVIATION...AMS/NF
CLIMATE...AMS
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1109 PM MDT TUE MAY 12 2015
.UPDATE...
ISSUED AT 918 PM MDT TUE MAY 12 2015
UPDATED FORECAST TO REFINE TIMING OF POPS THROUGH THE OVERNIGHT
HOURS AND INTO WEDNESDAY. SHOWERS AND THUNDERSTORMS HAVE
DECREASED ACROSS MOST OF THE FORECAST AREA...THOUGH STILL CONTINUE
ALONG THE CONTDVD. LATEST HRRR AND RAP SHOW PRECIPITATION WANING
ACROSS THE SE MTS...VALLEYS AND I-25 CORRIDOR THROUGH 08Z...THEN
INCREASING AGAIN AS FORCING FROM THE UPPER TROF ACROSS THE DESERT
SOUTHWEST STARTS APPROACHES THE REGION. THESE WILL THEN START TO
SPREAD INTO THE SOUTHERN I-25 CORRIDOR AFTER 12Z...THEN INTO ALL
OF THE SOUTHEAST PLAINS BY WED AFTERNOON AS THE UPPER TROF LIFTS
INTO THE TX/OK PANHANDLES AND SE CO BY 00Z. NICE WAA/OVERRUNNING
PATTERN SETS UP ACROSS THE FAR SOUTHEAST PLAINS...AND ALTHOUGH QPF
LOOKS HEAVIEST TO OUR SOUTH AND EAST OF THE AREA...THE SOUTHEAST
PLAINS SHOULD SEE A BOUT OF MODERATE RAINFALL WEDNESDAY
AFTERNOON...PARTICULARLY TO THE EAST OF LHX. ADJUSTED POPS
SLIGHTLY FOR TIMING. NOT A LOT OF CAPE OR SHEAR TO WORK WITH...SO
MAIN THREAT TOMORROW WILL BE THE POTENTIAL FOR LOCALIZED FLASH
FLOODING ACROSS THE SOUTHEAST PLAINS WITH ANY EMBEDDED CONVECTIVE
ELEMENTS...ESPECIALLY SINCE SOIL IS ALREADY SATURATED AND RIVER IS
RUNNING HIGH. -KT
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 337 PM MDT TUE MAY 12 2015
CURRENTLY...A DEEP UPPER TROUGH OF LOW PRESSURE OVER THE WEST COAST
WAS DRAWING MOISTURE UP ACROSS OLD MEXICO...AZ AND NM INTO THE 4
CORNERS. MID AND HIGH LEVEL MOISTURE WAS STREAMING INTO WESTERN
COLORADO...AND CLOUD COVER WAS ON THE INCREASE ACROSS THE WESTERN
HALF OF THE STATE THIS AFTN. A GOOD AMOUNT OF LTG ACTIVITY WAS
EVIDENT IN NM...BUT AS OF 3 PM NO CONVECTION YET ACROSS THE CWA.
STRONG SOUTHERLY SFC WINDS HAVE HELPED TO WARM TEMPS INTO THE MID
60S TO MID 70S ACROSS MUCH OF THE AREA.
TONIGHT AND TOMORROW...MODELS HAVE BEEN FAIRLY CONSISTENT ON KEEPING
SW FLOW ALOFT ACROSS THE REGION OVER THE NEXT 24 HRS. AN UPPER
DISTURBANCE IN THE LARGE SCALE SW FLOW WILL TRACK ACROSS THE 4
CORNERS REGION AND COLORADO TONIGHT AND TOMORROW...AND WILL BE THE
MAIN DRIVER OF CONVECTION SWEEPING ACROSS THE CWA. THE ENHANCED LTG
ACTIVITY CURRENTLY OCCURRING IN NM IS ASSOCIATED WITH THE BEST
DYNAMICS...AND IT LOOKS AS IF THIS AREA OF BEST FORCING WILL TRACK
ACROSS SOUTHERN NM TONIGHT...THEN UP ACROSS EASTERN NM...THE
PANHANDLES AND EASTERN COLORADO WED AFTN. THEREFORE...FEEL THAT
STEADILY INCREASING CLOUD COVER AND PCPN CHANCES FOR THE HIGHER
ELEVATIONS THIS EVE AND OVERNIGHT LOOKS REASONABLE...BUT THE
BULLSEYE FOR CONVECTION WILL THEN FOCUS ON THE SE QUAD OF THE STATE
BEGINNING AFTER 18Z. THE ENTIRE FORECAST AREA IS OUTLOOKED FOR
GENERAL THUNDER TOMORROW...AND LATEST NAM GUIDANCE INDICATE 600-700
J/KG OF CAPE FOR THE SE CORNER SO DO NOT BELIEVE THE AREA WILL SEE
MUCH BY WAY OF SEVERE WX...BUT THUNDERSTORM ACTIVITY IS PROBABLE. AS
FOR TEMPS...INCREASED CLOUD COVER SHOULD KEEP TEMPS MILD TONIGHT
WITH OVERNIGHT MINS IN THE 40S TO NEAR 50F...AND MAX TEMPS TOMORROW
IN THE 60S. MOORE
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 337 PM MDT TUE MAY 12 2015
.WEDNESDAY NIGHT THROUGH FRIDAY...DISTURBANCE EXITS THE STATE
WEDNESDAY EVENING. KEPT HIGHER POPS OVER THE EASTERN PLAINS CLOSER
TO THE KANSAS BORDER. ANTICIPATE NEARLY ALL THE PRECIPITATION
WILL BE EAST OF COLORADO BY MIDNIGHT. ON THURSDAY...STRONG TROUGH
WILL START LIFTING NORTHEASTWARD FROM SOUTHERN CALIFORNIA INTO
WYOMING. ISOLATED TO SCATTERED CONVECTION WILL DEVELOP DURING THE
AFTERNOON AS A WEAK DISTURBANCE MOVES UP FROM THE SOUTHWEST. WEAK
LEE TROUGH WILL DEVELOP OVER THE PLAINS DURING THE DAY...WITH MUCH
OF THE LOWER LEVEL MOISTURE REMAINING IN KANSAS. WITH LOW CAPE
VALUES...DO NOT ANTICIPATE ANY STRONG STORMS. ON FRIDAY...DRY SLOT
MOVES INTO THE EASTERN HALF OF THE CWA FROM THE SOUTHWEST. MODELS
HAVE TRENDED TO HAVE THE DRY LINE BE FURTHER EAST...MOSTLY OUT OF
COLORADO. IF THIS TREND CONTINUES...THREAT FOR SEVERE CONVECTIVE
WEATHER WILL BE LESS THAN EARLIER ANTICIPATED. THERE WILL BE
ENOUGH MOISTURE AND INSTABILITY FOR STORMS OVER THE MOUNTAINS
DURING THE DAY ON FRIDAY.
.SATURDAY AND SUNDAY...TROUGH WILL CONTINUE MOVING TO THE
NORTHEAST. A DISTURBANCE WILL ROTATE EASTWARD ACROSS THE STATE ON
SATURDAY...WHICH WILL INCREASE PRECIPITATION CHANCES OVER THE
MOUNTAINS. LEE TROUGH WILL BE EAST OF THE COLORADO BORDER ON
SATURDAY...WHICH WILL LIMIT THE AMOUNT OF LOW LEVEL MOISTURE ON
THE PLAINS. ON SUNDAY...TROUGH WILL MOVE WELL EAST OF THE REGION.
DIURNAL CONVECTION WILL MOSTLY BE CONFINED TO THE MOUNTAINS. COLD
FRONT WILL PASS OVER THE PLAINS ON SUNDAY...BUT MOISTURE BEHIND
THE FRONT WILL BE LIMITED.
.MONDAY AND TUESDAY...TROUGH RELOADS OVER CALIFORNIA...WITH A
DISTURBANCE PASSING OVER THE REGION TUESDAY OR WEDNESDAY. WITH
LOW LEVEL UPSLOPE CONTINUING...TUESDAY HAS THE POTENTIAL TO BE A
WET DAY. CURRENTLY...DID NOT GO VERY HIGH WITH THE POPS AS THIS IS
DAY 7. THERE ARE STILL ISSUES WITH THE TIMING AND STRENGTH OF THE
TROUGH. --PGW--
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1106 PM MDT TUE MAY 12 2015
KALS...SHOWERS ARE FORECAST TO MOVE INTO THE SAN LUIS VALLEY
OVERNIGHT BRINGING MVFR CONDITIONS TO THE TERMINAL DUE TO REDUCED
CIGS AND VIS. THERE WILL LIKELY BE A BREAK WEDNESDAY MORNING WITH
THUNDERSTORMS DEVELOPING WEDNESDAY AFTERNOON NEAR THE TERMINALS.
KCOS AND KPUB...VFR CONDITIONS OVERNIGHT. SHOWERS AND
THUNDERSTORMS ARE EXPECTED ON WEDNESDAY AFTERNOON WITH MAY BRING
REDUCED CIGS AND VIS TO THE TERMINALS. MOZLEY
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KT
SHORT TERM...MOORE
LONG TERM...PGW
AVIATION...MOZLEY
AREA FORECAST DISCUSSION
NWS TOPEKA KS
351 AM CDT Wed May 13 2015
.SHORT TERM...(Today and Tonight)
Issued at 350 AM CDT WED MAY 13 2015
Forecast focus is on onset of precip/amnts tonight. Clouds will be
on the increase today as moisture advection in advance of the upper
wave now across SW TX moves northward. Have trimed back onset time
of precip to mainly after 22Z given trends in obs and short term
models so bulk of the day should be dry. Widespread rain and
isolated thunder will occur after 03z tonight as moisture transport
increases ahead of the upper wave. Greatest instability and upper
divergence is fcst to remain south of the area overnight so expect
heaviest rains to remain south of the area however still expect
widespread 0.75 to 1.5 inch amounts given precip efficiency so all
in all the previous fcst looks good in that regard.
.LONG TERM...(Thursday through Tuesday)
Issued at 350 AM CDT WED MAY 13 2015
Showers and thunderstorms should be ongoing Thursday morning as
the shortwave passes across the forecast area. Models are
converging on a similar timing with precip moving off to the
northeast during the afternoon. Because of this have trended POPs
lower in the afternoon expecting subsidence behind the wave
increases. Models indicate warm air advection increasing behind
the rain Thursday. With some sunshine, highs could warm into the
mid 70s. Think this is more likely across central KS. Over
northeast KS where clouds and rain may linger longer into the
afternoon, have highs only in the lower 70s. Think that much of
Thursday night may end up being dry as the shortwave ridge passes
overhead. However the models seem to continue generating sporadic
QPF as the low level jet increases. Additionally the GFS hints at
a weak wave lifting through central KS early Friday morning.
Because of this have held onto some small POPs.
Friday is shaping up to be a little more interesting regarding
severe weather. Models are showing an area of low pressure
deepening over the high plains during the day. This causes the
dryline to mix into north central KS and a weak warm front to set
up mainly north of the forecast area. While the NAM seems to be
overdone with its dewpoints and resultant surface based
instability, there could be 2 to 3000 J/kg of CAPE by the
afternoon. While deep layer shear appears to be marginal, 0-1 KM
shear is progged to increase near the warm front and dryline. The
wild card is whether elevated precip in the morning allows for the
instability to form. This will be something to keep an eye on.
Chances for severe thunderstorms remains for Saturday and Saturday
night as well. The main upper low is expected to being moving out
of the Rockies with a dryline setting up across central KS. An
unstable airmass is likely to remain in place ahead of this dry
line as deep layer shear increases. Again the main question is
whether precip holds off until the afternoon or if there are
storms throughout the day.
Models have trended dry for Sunday as a cold front moves into the
area. This makes some since with the best forcing lifting into the
upper mid west. By Sunday night, cooler and dryer air is expected
to move into the central plains and bring a dry and cooler weather
through Tuesday. Highs Friday through Sunday should be in the
upper 70s to around 80. Temps for Monday and Tuesday are forecast
to be around 70 with the modified surface ridge over the area.
&&
.AVIATION...(For the 06Z TAFs through 06Z Wednesday Night)
Issued at 1145 PM CDT TUE MAY 12 2015
VFR expected through Wednesday afternoon. As showers increase
Wednesday evening, MVFR CIGS or VSBY are possible in the heavier
rain. Otherwise, expect light southeast winds tonight increasing
during the day on Wednesday with gusts to 20 KTS or more during
the afternoon. Forecast winds at low-levels from RAP and NAM would
suggest low-level wind shear is not very likely tonight, and did
not include in TAF.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...Omitt
LONG TERM...Wolters
AVIATION...GDP
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1150 PM CDT Tue May 12 2015
...Update to aviation forecast discussion...
.SHORT TERM...(This Evening through Wednesday)
Issued at 320 PM CDT TUE MAY 12 2015
This afternoon a mid-level ridge was stretching northwestward from
the southern U.S. into the Central and High Plains. Water vapor
imagery showed a closed mid-level low moving into northern
California and a weak disturbance present just east of the Baja
Peninsula at the base of the mid-level trough. Surface high pressure
prevailed over the region today and was slowly shifting eastward
this afternoon. With winds becoming more southerly this afternoon
and with mostly sunny skies prevailing, high temperatures were able
to rise into the upper 60s to low 70s. Despite the continued clear
skies, southerly flow overnight will keep temperatures warmer than
last night with lows in the mid/upper 40s.
Models show the weak disturbance near the Baja Peninsula
intensifying and lifting northeastward into Texas, Oklahoma, and
Kansas through the day on Wednesday. This advancing shortwave trough
will push an area of low pressure into the Southern Plains, which
will help to push the high pressure northeastward out of the area
and toward the Great Lakes region. With this surface pattern in
place, a bit of a pressure gradient will develop through the day on
Wednesday with gusty southeasterly winds by the afternoon. This
southerly flow should support modest warm-air advection into the
region with afternoon high temperatures in the low/mid 70s. Models
show the shortwave trough lifting over the area Wednesday night,
with model soundings showing increasing cloud cover by late
morning/early afternoon. The atmospheric profile looks to quickly
saturate across portions of central Kansas by mid/late afternoon
with PWAT values approaching 1.4 inches by early evening so expect
fairly widespread moderate rain showers to lift into the area.
Instability looks to be extremely weak, so only have a mention of
isolated thunder.
.LONG TERM...(Wednesday Night through Tuesday)
Issued at 320 PM CDT TUE MAY 12 2015
Wednesday night through Thursday, an upper level trough across
northwest Mexico will lift northeast across the southern and central
plains. The upper level trough will fill as if lifts northeast. A
lee surface trough will deepen across the southern plains. this will
allow deep gulf moisture to be advected northward across eastern KS.
The combination of strong isentropic lift and ascent ahead of the H5
trough axis will cause a large extensive area of moderate rainfall
to develop across eastern KS. The instability is forecasted to be
quite low with MUCAPES of only 50 to 300 J/KG through Thursday
morning. Any isolated to scattered thunderstorms will not be severe.
Precipitable Water is forecast to increase to 1.4 to 1.6 inches
Wednesday night into Thursday morning. The forecast sounding have
saturation from the surface up to nearly 500 mb. The warm rain
process will lead to a prolong period of steady rainfall. QPF
forecasts across the western half of the CWA will be around one inch
with 1 to 1.5 inches of rainfall across the eastern half of the CWA.
Due to the lack of stronger thunderstorms, this looks to be a long
duration rain even of 12 to 15 hours. I`m not expecting flash
flooding but some of the rivers and steams that are near bankfull
may spill over, causing some minor flooding. Low-lying areas and
flood prone areas may also experience some minor flooding. The rain
should move east of the CWA during the late morning hours as the
upper level trough lifts northeast across the upper Midwest.
Insolation during the late afternoon hours should help high
temperatures to warm into the lower to mid 70s.
Thursday night through early Friday, the deeper gulf moisture will
remain in place with weak south-southwesterly flow aloft. I suppose
if a weak vortmax or H5 trough lifts northeast across the area, a
few showers and thunderstorms could develop Thursday night into
Friday morning.
Friday afternoon through Friday night, another intense upper level
trough will dig southeast into the southwestern US. Increasing
southwesterly flow at mid to upper levels and steeper lapse rates
will cause the environment across eastern Kansas to become more
favorable for severe thunderstorms. However, an Elevated Mix Layer
will overspread eastern KS and may cap off any surface based storms
to develop. In western KS, a dryline will provide enough surface
convergence along with ascent ahead of 50 KT jet max to break the
cap and allow supercell thunderstorms to develop. The 12Z NAM
forecast mixes out the dryline into north central and central KS by
00Z SUN. It also shows a weak outflow boundary draped across east
central and northeast KS. The 12Z NAM generates 3,000 to 4,000 J/KG
of MLCAPE across the CWA. If a storm manages to develop along the
triple point along the NE border if would probably become severe.
Both the GFS and ECMWF keep the dryline farther west across west
central KS. The supercells that develop across west central KS will
move east and may congeal into a complex or QLCS through the evening
hours and move into eastern KS. If the line segments of storms
remain severe, then there will be a risk for large hail and damaging
winds Friday night. If the storms weaken the primary hazard would be
heavy rainfall.
Saturday and Saturday night, both the ECMWF and GFS are in good
agreement lifting the southwestern US trough northeast into the
central high plains. Both models show the dryline moving east from
eastern CO into west central KS through the day. A strong H5 jet max
will lift northeast across western and central KS. The surface
convergence ahead of the dryline and ascent ahead of the advancing
trough will allow for scattered thunderstorms develop. The
environment ahead of the dryline will have strong vertical wind
shear and moderate to high instability. Any thunderstorms that
develops ahead of the dryline will become supercellular which will
produce large hail, damaging winds and tornadoes. These supercells
will move northeast into central and north central KS during the
evening hours. Eventually the isolated to scattered supercells will
congeal into one or more QLCSs, where the primary hazard will become
more of a large hail and damaging wind threat through the mid
evening hours and extending into the early morning hours of Sunday.
Sunday, the upper level trough will lift northeast across NE into MN
by 12 Noon on Sunday. The showers and thunderstorms will push east
of the CWA during the mid morning hours. Sunday will turn out to be
a warm and drier day with highs reaching into the lower 80s across
much of the area.
Sunday night and Monday, A weak cold front will push southward
across the CWA. The front will not have much moisture ahead of it,
so I don`t expect showers to develop Sunday night. Monday will be
mostly sunny with highs in the lower 70s.
Monday night and Tuesday, An upper level ridge will amplify across
the plains. A lee surface trough across the central and southern
high plains will deepen through the day. Deeper moisture will begin
to return northward across TX into OK but the rain and thunderstorms
should remain south of KS through the afternoon hours.
&&
.AVIATION...(For the 06Z TAFs through 06Z Wednesday Night)
Issued at 1145 PM CDT TUE MAY 12 2015
VFR expected through Wednesday afternoon. As showers increase
Wednesday evening, MVFR cigs or vsbys are possible in the heavier
rain. Otherwise, expect light southeast winds tonight increasing
during the day on Wednesday with gusts to 20 kts or more during
the afternoon. Forecast winds at low-levels from RAP and NAM would
suggest low-level wind shear is not very likely tonight, and did
not include in TAF.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Hennecke
LONG TERM...Gargan
AVIATION...GDP
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
323 AM CDT WED MAY 13 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 320 AM CDT WED MAY 13 2015
TODAY AND TONIGHT...THE SUBTROPICAL DISTURBANCE OFF OF BAJA MEXICO
YESTERDAY HAS MOVED NORTH INTO NEW MEXICO THIS MORNING. THE MODELS
LIFT THIS DISTURBANCE THROUGH THE CNTL PLAINS TODAY AND TONIGHT.
TWO CONVECTIVE ITEMS OF INTEREST HAVE BEEN IDENTIFIED AS THE
DISTURBANCE MOVES THRU WRN AND NCNTL NEBRASKA LATE THIS AFTN AND
TONIGHT. ONE IS A ROUND OF CONVECTION THAT SHOULD FIRE ON THE
COLORADO FRONT RANGE AND LARAMIE RANGE AROUND 18Z-21Z. THE STEERING
WINDS ALOFT CARRY THIS CONVECTION NNE THROUGH THE NEB PANHANDLE
AFFECTING AREAS MAINLY ALONG AND WEST OF HIGHWAY 61. MEANWHILE THE
SREF AND GEF SUGGEST A SECOND HEAVIER RAIN CENTER WILL MOVE ACROSS
WCNTL KS AND THROUGH SCNTL/ERN NEB EXITING AROUND 12Z.
THE QUESTION THOUGH IS HOW FAR WEST THE SECOND RAIN CENTER WILL
TRACK GIVEN THAT THE MODELS TREND WEST WITH RETURN MOISTURE. THE RAP
AND NAM PROVIDE AN ANSWER AS THEY ARE FARTHEST WEST AT 00Z WITH PWAT
NEAR 1.25 INCHES AND BACKED 850MB NEAR PAMPA TX. THIS MOISTURE
SHOULD MOVE NORTH-NORTHEAST DURING THE EVENING PRESENTING THE
POTENTIAL FOR HEAVY RAIN...0.5 TO 1 INCH EAST OF HIGHWAY 83 ACROSS
CUSTER COUNTY AND NORTHEAST. THE 1 INCH QPF IS SPECULATIVE. THE
MOISTURE IS VERY DEEP AND TRANSPORT EXTENDS TO 500 MB OR HIGHER AND
IS QUITE STRONG BELOW 700MB. WE WILL SEE WHAT HAPPENS TONIGHT. IF
SOME SORT OF LOW LEVEL BOUNDARY OR FOCUS DEVELOPS...NOT SHOWN BY
THE MODELS ATTM...THAN THE 1 INCH QPF COULD VERIFY SOMEWHERE. THE
QPF FORECAST FOLLOWS THE SREF AND NAM FOR UP TO 1/2 INCH OF RAIN IN
THE EAST AND UP TO 1/3 OF AN INCH WEST OF HIGHWAY 61.
THE "HURRICANE" CONTINUES TODAY. THE RAP13 500M AGL WINDS INCREASE
TO 25 TO 30 KTS WHICH IS 25 TO 30 MPH NEAR THE SFC WITH GUSTS TO 40
MPH IN OPEN AREAS.
THE TEMPERATURE FORECAST TODAY FOLLOWS THE WARM SIDE OF THE MODEL
CLUSTER FOR HIGHS IN THE LOW TO MID 70S. THE RAP SHOWS 80 NEAR
VALENTINE AND 76 AT NORTH PLATTE. MID LEVEL CLOUDINESS SHOULD INVADE
THE REGION HOLDING HIGHS DOWN BELOW THE RAP FORECAST. LOWS TONIGHT
FALL INTO THE UPPER 40S TO MID 50S. THE NAM SHOWS OVERCAST SKIES AT
09Z WITH A CLEARING LINE NEAR HIGHWAY 61 AT 12Z EARLY THURSDAY
MORNING.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 320 AM CDT WED MAY 13 2015
THE LARGE SCALE UPPER LEVEL PATTERN PERSISTS THROUGH THE END OF THE
WEEK AND INTO EARLY NEXT WEEK...DEFINED BY A DEEP TROUGH WITH
SEVERAL EMBEDDED PV ANOMALIES IN THE WESTERN CONUS AND BROAD
ANTICYCLONIC FLOW TO THE EAST. THIS PUTS THE CENTRAL CONUS IN A
FAVORABLE SYNOPTIC SETUP FOR POLEWARD MOISTURE TRANSPORT AND
RECURRING CHANCES FOR PRECIPITATION...INCLUDING THE POTENTIAL FOR
SEVERE WEATHER LATER THIS WEEK.
THURSDAY BEGINS WITH INHERITED MORNING POPS AS A SHORTWAVE DEPARTS
THE CENTRAL PLAINS AND MOVES INTO THE UPPER MS VALLEY. MODELS ARE IN
AGREEMENT WITH UPPER LEVEL HEIGHT RISES AND GRADUALLY CLEARING SKIES
BY THE AFTERNOON...SO TRENDED HIGH TEMPERATURES UP A FEW DEGREES TO
FOLLOW GUIDANCE. SFC WINDS WILL FINALLY EASE UP FOR A DAY DUE TO
WEAK PRESSURE TENANCIES OVER THE CWA...GENERALLY EXPECTING WINDS
AROUND 10 KTS.
POPS ARE QUICK TO MOVE BACK INTO THE FORECAST LATE THURSDAY AS THE
NEXT SHORTWAVE TROUGH ENTERS THE DESERT SOUTHWEST AND SWINGS OUT
TOWARD THE CENTRAL PLAINS. INCREASING DPVA ALOFT WILL PROMOTE A
DEEPENING LEE SIDE SFC TROUGH OVER EASTERN COLORADO AND THE SLOW
NORTHWARD PROGRESSION OF A WARM FRONT INTO NORTHERN KS. DEEP LAYER
MOISTURE PROFILE WILL BECOME INCREASINGLY FAVORABLE FOR
PRECIPITATION DUE TO EASTERLY UPSLOPE WINDS...AND A MID-LEVEL
SUBTROPICAL PLUME OFF THE BAJA TRANSPORTS BETTER MOISTURE ALOFT.
SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP AFTER DARK IN AN
AREA OF ISENTROPIC ASCENT NORTH OF THE WARM FRONT. THE CONVECTION
SHOULD FOLLOW THE WARM FRONT NORTHWARD INTO SOUTHERN SD EARLY
FRIDAY.
SEVERE WEATHER THREAT INCREASES FRIDAY AFTERNOON AND EVENING WITH
THE NEXT ROUND OF THUNDERSTORM ACTIVITY. SFC DEWPOINTS INCREASE TO
AROUND 60F INVOF A SHARPENING DRY LINE OVER WESTERN KS AND SOUTHWEST
NEBRASKA AND SOUTH OF THE WARM FRONT IN SOUTHERN SD. THE ATMOSPHERE
WILL BECOME QUITE UNSTABLE BY THE AFTERNOON AS MID LEVEL LAPSE RATES
STEEPEN AND SFC TEMPS WARM. THUNDERSTORMS SHOULD REFIRE ALONG THE
DRYLINE DURING THE AFTERNOON AND EVENING AS THE DRYLINE SURGES
NORTHEAST. STORMS WILL HAVE THE POTENTIAL TO BECOME SUPERCELLULAR IN
AN ENVIRONMENT CHARACTERIZED BY UP TO 2000 J/KG ML CAPE AND 40-45
KTS OF DEEP LAYER SHEAR. LARGE HAIL AND DAMAGING WIND WILL BE THE
PRIMARY THREATS...BUT LOW LEVEL SFC SHEAR PROFILES FAVOR ELONGATED
HODOGRAPHS AND THE POTENTIAL FOR A FEW TORNADOES.
THUNDERSTORMS AND THE THREAT FOR SEVERE WEATHER REDEVELOP SATURDAY
AS THE LARGE UPPER LEVEL LOW EJECTS TOWARD THE CENTRAL PLAINS. AT
THIS TIME THE AREA OF CONCERN IS GENERALLY EAST OF A SFC TROUGH
MOVING INTO CENTRAL AND EASTERN NEBRASKA. THE EARLY PART OF NEXT
WEEK LOOKS DRIER AS THE UPPER LOW KICKS NORTHEAST AND A RIDGE BUILDS
INTO THE CENTRAL CONUS. HOWEVER MODELS ARE QUICK TO BRING ANOTHER
TROUGH INTO THE ROCKIES BY TUESDAY...BRINGING WITH IT MORE CHANCES
FOR SHOWERS AND THUNDERSTORMS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1129 PM CDT TUE MAY 12 2015
UNLIMITED CEILING AND VISIBILITY CAN BE EXPECTED THROUGH MOST OF THE
DAY WEDNESDAY. THUNDERSTORMS ARE EXPECTED TO BEGIN DEVELOPING IN
EXTREME WESTERN NEBRASKA EARLY AFTERNOON AND ARE LIKELY TO SPREAD
INTO THE REST OF WESTERN NEBRASKA LATE AFTERNOON THROUGH EARLY
EVENING. BY EARLY EVENING...THE COVERAGE OF THE STORMS WILL BE 50
PERCENT OR HIGHER AND WE WILL INCLUDE THEM IN THE FORECASTS FOR LBF
AND VTN. STORMS WILL THEN MAKE THEIR WAY INTO CENTRAL NEBRASKA TO
AFFECT ONL...BBW...ANW.
WIND TONIGHT WILL CONTINUE 130-170 AT 12-16KT AND...BY 16Z INCREASE
AND BECOME 160-200 AT 16-20G25-30KT.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...MARTIN
AVIATION...SPRINGER
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
127 AM EDT WED MAY 13 2015
.SYNOPSIS...
LESS HUMID AIR WILL ARRIVE TODAY BEHIND A COLD FRONT AND SHOULD LAST
INTO THURSDAY AS HIGH PRESSURE MOVES OVERHEAD. THE LATTER PART OF
THE WEEK AND WEEKEND WILL FEATURE A GRADUAL INCREASE IN HUMIDITY AND
THUNDERSTORM CHANCES AS THE HIGH MOVES OFF THE COAST.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
AS OF 120 AM WEDNESDAY...I HAVE RAISED FORECAST LOWS BY SEVERAL
DEGREES ALONG THE COAST. FROPA SHOULD NOT OCCUR UNTIL 5:00-5:30 AM
AT THE BEACHES WHICH LEAVES ONLY A SHORT WINDOW FOR ANY SIGNIFICANT
RADIATIONAL/ADVECTIVE COOLING TO OCCUR BEFORE SUNRISE. RADAR HAS
CLEARED OUT...ALTHOUGH THE LATEST FEW HRRR RUNS STILL INDICATE SOME
LINGERING SHOWER POTENTIAL UP THROUGH FROPA ACROSS SE NORTH
CAROLINA. I HAVE REMOVED THUNDER AS THERE IS A STABLE ENOUGH
INVERSION ALOFT TO RULE OUT DEEP CONVECTION OVER LAND. DISCUSSION
FROM 1030 PM TUESDAY FOLLOWS...
BASED ON LATEST SHOWER AND TSTORM ACTIVITY AND COVERAGE...LOW CHANCE
POPS TO CONTINUE AHEAD OF THE APPROACHING COLD FRONT...AND THAT IS
BEING GENEROUS. CLOUDS AND CONVECTION TO QUICKLY CLEAR OUT AFTER THE
CFP. ALSO...THOSE MISERABLE 70+ DEGREE DEWPOINTS TO MIGRATE AWAY
FROM THE FA AFTER FROPA. WE HAVE THE WHOLE SUMMER AHEAD TO
EXPERIENCE THOSE 70+ DEGREE DEWPOINTS. THE THREAT FOR ANY SEVERE
ACTIVITY HAS BEEN NEGATED. CURRENT MIN TEMP FORECAST STILL AOK.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...
AS OF 318 PM TUESDAY...CHANGING OF THE GUARD SO TO SPEAK IN TERMS
OF AIR MASS REPLACEMENT THIS PERIOD...AS A COLD FRONT MIGRATES
OFF THE COAST AROUND DAYBREAK WEDNESDAY. POST FRONTAL N WIND WILL
TEND TO NE WEDNESDAY ACCOMPANIED BY LOWERING DEWPOINTS IN THE 50S
MAKING FOR CONSIDERABLY LESS MUGGINESS...WITH MAXIMUMS OF UPPER
70S TO LOWER 80S WITH SUN. EARLY THURSDAY SEASONABLY COOL MINIMUMS
OF UPPER 50S TO LOWER 60S...MILDEST COAST. A COOLER DAY SETTING UP
THURSDAY AS HIGH PRESSURE FROM THE GREAT LAKES DROPS SOUTHEAST
TOWARD THE CAROLINAS...SUPPLYING A DOSE OF COOL AIR ADVECTION.
MINIMUMS EARLY FRIDAY SIMILAR TO THURSDAY UPPER 50S TO LOWER 60S.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 318 PM TUESDAY...TRANSITION PERIOD AS HIGH PRESSURE MOVES
OFFSHORE FRIDAY AND RETURN FLOW RESUMES ACROSS THE AREA. THIS
WILL BRING A TREND UPWARD IN TEMPERATURES AND HUMIDITY WITH AN
INCREASING CHANCE OF SHOWERS/TSTMS AS A COLD FRONT GRADUALLY
APPROACHES FROM THE WEST THIS WEEKEND. THE FRONT MAY STALL OVER
THE AREA EARLY NEXT WEEK...OFFERING HIGH HUMIDITY AND EVEN A
BETTER CHANCE OF PCPN INTO EARLY NEXT WEEK. THIS REGIME SHOULD
RESULT IN TEMPERATURES NEAR OR SLIGHTLY ABOVE CLIMATE STANDARDS
FOR MIDDLE MAY.
&&
.AVIATION /06Z WEDNESDAY THROUGH MONDAY/...
AS OF 06Z...THE COLD FRONT SHOULD MOVE OFF THE COAST AROUND 10Z. AN
ISOLATED SHOWER CAN NOT BE RULED OUT...BUT IT IS A REMOTE
POSSIBILITY. POST FRONTAL...LOOK FOR NORTHERLY WINDS AROUND 10 KTS
WITH A MID CLOUD CEILING WORST CASE. AFTER DAYBREAK...VFR CONTINUES.
WINDS WILL VEER TO THE NORTHEAST BY MID MORNING...BECOMING EASTERLY
ALONG THE COAST IN THE AFTERNOON.
EXTENDED OUTLOOK...VFR. ISOLATED SHOWERS FRIDAY...BECOMING SCATTERED
SAT AND SUN. BETTER CHANCES FOR CONVECTION MON.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 120 AM WEDNESDAY...RAISED WIND SPEEDS A BIT FROM NOW UP UNTIL
THE COLD FRONT ARRIVES AT THE BEACHES AROUND 5-6 AM. OFFSHORE IT`S
GUSTING TO 25 KT AT FRYING PAN SHOALS..WITH 10-15 KT GUSTS AT THE
BEACHES. ALSO RAISED NEARSHORE WAVE HEIGHT FORECASTS TO FIT
CONCEPTUAL MODELS OF ONSHORE/LONGSHORE WINDS AND 3-4 FOOT SEAS AT 5-
20 MILE DISTANCES OFFSHORE. DISCUSSION FROM 1030 PM TUESDAY
FOLLOWS...
SSW-SW WINDS 15 TO 20 KT TO PREVAIL WELL INTO TONIGHT...DIMINISHING
TO 10-15 KT AS THE COLD FRONT APPROACHES...AND LIKELY VEERING TO THE
NW-N AROUND 15 KT BY DAYBREAK WED AFTER FROPA. SIGNIFICANT SEAS WILL
RUN 2 TO 4 FT...HIGHEST ACROSS THE WATERS FROM CAPE FEAR SOUTH TO
LITTLE RIVER INLET WHERE THE FETCH IS GREATEST GIVEN THE WIND
DIRECTION. A 1 TO 2 FOOT 7-8 SECOND PERIOD GROUND SWELL REMAINS
IDENTIFIABLE...BUT WIND DRIVEN WAVES AT 4 TO 5 SECONDS WILL DOMINATE
THE SIGNIFICANT SEAS.
SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
AS OF 318 PM TUESDAY...A COLD FRONTAL PASSAGE TO BRING A
WINDSHIFT TO NORTH ON THE WATERS WEDNESDAY...TENDING TO NE AND ENE
HEADING INTO LATER WEDNESDAY AND THURSDAY. NO ADVISORIES BUT NE GUSTS
TO 20 KT EXPECTED EARLY THURSDAY AS HIGH PRESSURE BUILDS FROM THE
NW. SEAS 2-3 FEET WEDNESDAY WILL BUILD TO 3-4 FEET THURSDAY. NO
TSTMS OR VISIBILITY RESTRICTIONS ON THE 0-20 NM WATERS EXPECTED
WED/THU/
.LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 318 PM TUESDAY...A TRANSITION TO A BERMUDA HIGH PRESSURE
PATTERN AS HIGH PRESSURE MOVES OFFSHORE AND RETURN SW WINDS PREVAIL
BEGINNING FRIDAY AND PERSISTING THROUGH THE WEEKEND. WARMING
DAYTIME TEMPERATURES WILL DRIVE A SEA BREEZE AND AFTERNOON GUSTS
TO 20 KT SHOULD BE EXPECTED NEAR SHORE OVER THE WEEKEND. ISOLATED
SHOWERS AND TSTMS SHOULD ALSO BE EXPECTED INTO THE WEEKEND AS S
AND SW WINDS INTRODUCE ADDITIONAL MOISTURE INTO THE REGION.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MJC/TRA
NEAR TERM...TRA
SHORT TERM...MJC
LONG TERM...SHK
AVIATION...DL/TRA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1255 AM CDT WED MAY 13 2015
.UPDATE...
ISSUED AT 1256 AM CDT WED MAY 13 2015
BAND OF SHOWER EXTENDED FROM AROUND MINOT EASTWARD TO RUGBY/DEVILS
LAKE AND SHOULD CONTINUE MOVING NORTHWARD EARLY THIS MORNING TOWARD
THE CANADIAN BORDER. OTHER MORE ISOLATED SHOWERS IN SOUTHEASTERN
MONTANA AND WESTERN SOUTH DAKOTA WERE MOVING NORTHEASTWARD INTO
BOWMAN COUNTY...AND KEPT A CHANCE/SLIGHT CHANCE OF SHOWERS FOR MUCH
OF WESTERN AND CENTRAL NORTH DAKOTA. SHORT TERM MODELS HANDLING THE
NORTHERN BAND OF SHOWERS WELL...AND MORE ISOLATED SHOWERS SOUTHWEST
ARE ASSOCIATED WITH SMALL UPPER LEVEL ENERGY IMPULSES MOVING
NORTHEAST OUT OF THE CENTRAL ROCKIES. SURFACE LOW OVER WYOMING WITH
A TIGHTENING PRESSURE GRADIENT WAS ASSOCIATED WITH INCREASING
EASTERLY WINDS OVER SOUTHWEST/SOUTH CENTRAL NORTH DAKOTA...SO
INCREASED WINDS THIS AREA A BIT FOR THE OVERNIGHT HOURS. TEMPERATURE
TREND ON TRACK.
UPDATE ISSUED AT 938 PM CDT TUE MAY 12 2015
AT 930 PM CDT...BAND OF SHOWERS CONTINUES TO TREND NORTH AND EAST
NOW ALONG A LAKE SAKAKAWEA SOUTHEAST INTO JAMESTOWN LINE. WILL
TREND THE HIGHER POPS SLOWLY EAST NORTHEAST THROUGH THE REMAINDER
OF THE EVENING. AFTER MIDNIGHT MODELS DEPICT LIFT OVER A WARM
FRONT ACROSS SOUTH DAKOTA THAT WILL FAVOR INCREASED CLOUDS AND
SCATTERED SHOWERS OVER THE REGION AS THE CURRENT FORECAST HAS
GOING.
UPDATE ISSUED AT 654 PM CDT TUE MAY 12 2015
BAND OF RAIN SHOWERS MOVING THROUGH CENTRAL NORTH DAKOTA. UPDATED
THE POPS/SKY GRIDS BASED ON THESE HRRR TRENDS. FOCUSED HIGHEST
POPS EAST OF BISMARCK FOR THE EVENING.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 259 PM CDT TUE MAY 12 2015
FORECAST HIGHLIGHTS IN THE SHORT TERM PERIOD WILL BE PRECIPITATION
CHANCES THROUGH THE PERIOD.
CURRENTLY...ZONAL FLOW ALOFT WITH A CLOSED MID LEVEL LOW OVER FAR
SOUTH CENTRAL CANADA AND A RIDGE AXIS STRETCHING FROM THE CENTRAL
PLAINS NORTHWEST INTO SOUTHERN MONTANA. EMBEDDED S/WV IMPULSE
MOVING ALONG THE ND/SD BORDER WILL BRING A DECENT CHANCE FOR
SHOWERS TO SOUTHERN PORTIONS OF NORTH DAKOTA THIS AFTERNOON AND
EVENING. EXPECT MOISTURE TO REMAIN BELOW A TENTH OF AN INCH...WITH
MOST LOCATIONS SEEING A TRACE OR PERHAPS A FEW HUNDREDTHS.
CLOUDS AND CHANCES FOR SHOWERS CONTINUE TONIGHT WITH MODELS
DEPICTING SEVERAL SMALL-SCALE EMBEDDED WAVES PUSHING EAST ACROSS
THE REGION ALONG WITH A PERSISTENT AND MOIST EAST/SOUTHEASTERLY
LOW/MID LEVEL FLOW REGIME. MODELS ARE KEYING IN ON MY NORTH
CENTRAL AND EAST TONIGHT FOR BEST CHANCES AND HIGHEST MOISTURE
WHERE BEST FORCING WILL RESIDE. LOWS TONIGHT MAINLY IN THE 40S.
FOR WEDNESDAY...WARM FRONTAL BOUNDARY NOW OVER SOUTHERN SOUTH
DAKOTA WILL LIFT SLOWLY NORTH LATER TONIGHT INTO
WEDNESDAY...REACHING THE ND/SD BORDER MID TO LATE AFTERNOON. ALONG
THE WARM FRONT MUCAPE 500-1200 J/KG WILL SLOWLY CREEP INTO MY FAR
SOUTHWEST AND FAR SOUTH CENTRAL COUNTIES. 0-6KM SHEAR MODEST AT
25-35KTS DEPENDING ON WHICH MODELS IS USED. SO THERE APPEARS TO BE
SOME POTENTIAL FOR STRONG CONVECTION AND WILL BE WORTH LOOKING
MORE CLOSELY AT OVER THE NEXT 12-18 HOURS TO SEE HOW MODELS
TREND.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 259 PM CDT TUE MAY 12 2015
UNSETTLED WEATHER REMAINS ON TRACK WITH RAIN SHOWERS AND A CHANCE OF
THUNDERSTORMS WEDNESDAY NIGHT INTO THURSDAY...FOLLOWED BY A BRIEF
BREAK THURSDAY NIGHT THROUGH MOST OF FRIDAY. THEN A SIGNIFICANT
WEATHER SYSTEM/VERTICALLY STACKED AND SLOW MOVING OVER THE WEEKEND
LOOKS TO PRODUCE WIDESPREAD RAIN SHOWERS AND POSSIBLY SEVERE
THUNDERSTORMS. DRIER WEATHER MONDAY AND TUESDAY.
WEDNESDAY NIGHT THROUGH THURSDAY...A 700MB UPPER LOW WITH A SURFACE
REFLECTION/WARM FRONT STRETCHING FROM CENTRAL SOUTH DAKOTA INTO
SOUTH CENTRAL NORTH DAKOTA WILL SHIFT EAST THROUGH THURSDAY. HIGH
CHANCE TO LIKELY POPS ACROSS CENTRAL NORTH DAKOTA WITH CHANCES
DECREASING FARTHER WEST. MOST UNSTABLE CAPE ACROSS SOUTHWEST INTO
SOUTH CENTRAL NORTH DAKOTA AROUND 500 J/KG WITH 0-6KM BULK SHEAR
EARLY WEDNESDAY NIGHT AT AROUND 25-30KT...THEN DECREASING THE REST
OF WEDNESDAY NIGHT INTO THURSDAY. WILL CONTINUE TO MENTION A CHANCE
FOR THUNDERSTORMS WEDNESDAY NIGHT BUT LEAVE OUT ANY MENTION ON
THURSDAY.
THURSDAY NIGHT THROUGH FRIDAY...A TRANSITORY MID LEVEL RIDGE SLIDES
THROUGH CENTRAL NORTH DAKOTA FRIDAY AFTERNOON ALLOWING MOISTURE AND
THE NEXT POTENT MID/UPPER LEVEL SHORTWAVE IN WYOMING TO IMPINGE
ACROSS SOUTHWESTERN NORTH DAKOTA FRIDAY AFTERNOON. CAPE VALUES
FORECAST NEAR 1000 J/KG IN THE FAR SOUTHWEST WITH AROUND 25KT OF 0-
6KM BULK SHEAR. HENCE WILL MENTION A CHANCE OF THUNDERSTORMS IN THIS
AREA FRIDAY AFTERNOON WITH SHOWERS ELSEWHERE IN THE WEST AND
PORTIONS OF SOUTH CENTRAL NORTH DAKOTA.
FRIDAY NIGHT THROUGH SUNDAY NIGHT...A POTENT CLOSED/VERTICALLY
STACKED UPPER LOW IS FORECAST TO TRANSLATE FROM SOUTHEAST MONTANA
FRIDAY NIGHT...ACROSS NORTHERN SOUTH DAKOTA SATURDAY NIGHT...AND
THEN INTO WESTERN MINNESOTA SUNDAY NIGHT. FRIDAY NIGHT THROUGH
SATURDAY NIGHT...THE TRACK OF THE UPPER LOW/SURFACE LOW PUTS MOST OF
CENTRAL AND SOUTHERN NORTH DAKOTA IN THE WARM SECTOR. UNCERTAINTY
REMAINS ON HOW MUCH OF A DRY SLOT...IF ANY...WILL WORK ITS WAY INTO
SOUTHERN/CENTRAL NORTH DAKOTA. SEVERE WEATHER IS POSSIBLE SATURDAY
INTO SATURDAY NIGHT. DETAILS ON EXACTLY WHERE THIS WILL OCCUR STILL
IN QUESTION PER 12Z GFS AND 12Z ECMWF. WITH THE SURFACE LOW AND WARM
FRONTAL POSITION LOCATED OVER SOUTH CENTRAL NORTH DAKOTA SATURDAY
AFTERNOON...THE BEST INSTABILITY AND SHEAR RESIDES ALONG AND
NORTH...WHICH WOULD PLACE NORTHWEST/NORTH CENTRAL/AND THE JAMES
RIVER VALLEY IN A PRIME LOCATION. THE GFS PORTRAYS THIS MORE THAN
THE ECMWF. THE ECMWF KEEPS THE GREATEST INSTABILITY AND SHEAR MAINLY
OVER SOUTH CENTRAL NORTH DAKOTA AND THE JAMES RIVER VALLEY. THIS
WILL LIKELY CHANGE OVER THE COMING DAYS...SO WILL BE ABLE TO HONE IN
ON THIS MORE IN THE NEXT FEW DAYS. CAPE VALUES ARE FORECAST BETWEEN
1000-2000 J/KG WITH 0-6KM BULK SHEAR OF 35KT TO 45KT IN THE GREATEST
AREAS OF INSTABILITY ON BOTH MODELS. WILL CONTINUE TO CLOSELY
MONITOR.
MONDAY INTO TUESDAY...BOTH THE GFS AND ECMWF SHOW THE WEEKEND STORM
DEPARTING SUNDAY NIGHT LEAVING MONDAY/MONDAY NIGHT DRY WITH A
TRANSITORY 700MB-500MB RIDGE MIGRATING FROM SOUTHWEST TO NORTHEAST.
ANOTHER UPPER LOW IS FORECAST TO FOLLOW A SIMILAR PATH FOR TUESDAY
AND WEDNESDAY WITH POTENTIALLY ANOTHER WIDESPREAD PRECIPITATION
EVENT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1256 AM CDT WED MAY 13 2015
AT MIDNIGHT CDT...A SURFACE LOW PRESSURE SYSTEM WAS CENTERED OVER
WYOMING...WITH A WARM FRONT EXTENDING EASTWARD FROM THE LOW ACROSS
SOUTH DAKOTA. THE SURFACE PRESSURE GRADIENT WAS INCREASING...AND
EXPECTING GUSTY EASTERLY WINDS THIS MORNING AT TAF SITES - WITH
STRONGEST WINDS ACROSS SOUTHERN TERMINALS OF KISN/KBIS/KJMS. SHORT
TERM MODELS INDICATE DEVELOPMENT AND EXPANSION OF MVFR
CIGS WITH RAIN SHOWERS AT KISN/KMOT/KDIK BETWEEN 06Z-09Z. LESS
CONFIDENCE ON MVFR CIGS AT KBIS/KJMS UNTIL AFT 09Z. WARM FRONT LIFTS
NORTHWARD INTO NORTH DAKOTA DAYTIME WEDNESDAY AND BECOMES ORIENTED
NORTHEAST-TO-SOUTHWEST ACROSS EASTERN/CENTRAL NORTH DAKOTA WITH A
FOCUS FOR MVFR CIGS AND RAIN SHOWERS MAINLY AFT 00Z THURSDAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JV
SHORT TERM...NH
LONG TERM...KS
AVIATION...JV
AREA FORECAST DISCUSSION
NWS PENDLETON OR
1030 PM PDT TUE MAY 12 2015
UPDATED AVIATION DISCUSSION
.SHORT TERM...TONIGHT AND WEDNESDAY...UPPER LEVEL LOW PRESSURE
SYSTEM CONTINUES TO IMPACT THE REGION. A SURGE OF SHORTWAVE ENERGY
WRAPPING AROUND THE LOW IS COMING UP OUT OF NORTHWEST NEVADA WHICH
IS ACTING TO ENHANCE CONVECTIVE SHOWERS OVER FAR EASTERN OREGON.
THIS SHORTWAVE WILL PIVOT INTO NORTHEAST OREGON OVERNIGHT AND THEN
INTO EASTERN WASHINGTON EARLY WEDNESDAY. THE SHOWERS BEING GENERATED
AHEAD OF THIS SHORTWAVE ARE EXPECTED TO CONTINUE TO ENHANCE AND
BECOME MORE CLUSTERED TOGETHER AS A PRECIPITATION SHIELD. THIS AREA
OF PRECIPITATION HAS THE POTENTIAL TO PRODUCE SOME SIGNIFICANT
AMOUNTS OF RAIN AS IT PASSES THROUGH THE FORECAST AREA OVERNIGHT AND
WEDNESDAY ON THE ORDER OF AROUND HALF AN INCH IN THE LOW ELEVATIONS
AND AN INCH OR MORE IN THE MOUNTAINS. FORECAST HAS BEEN UPDATED TO
INCREASE THE CHANCE OF PRECIPITATION AND AMOUNT OF PRECIPITATION
OVERNIGHT AND WEDNESDAY.
.AVIATION...06Z TAFS...MVFR CONDITIONS CAN BE EXPECTED OVER THE NEXT
6-12 HOURS...AS A DEFORMATION BAND IS EXPECTED TO SET UP OVER
NORTHERN OREGON AND SOUTHERN WASHINGTON DURING THIS PERIOD. THIS
COULD ALLOW FOR PERIODS OF MODERATE RAIN...WITH CIGS POSSIBLY
FALLING TO IFR CATEGORIES. WINDS WILL RANGE FROM 5 TO 15 KTS...WITH
GUSTS UP TO 25 KTS.
&&
.PREV DISCUSSION... /ISSUED 351 PM PDT TUE MAY 12 2015/
SHORT TERM...TUESDAY NIGHT THROUGH THURSDAY NIGHT. AN INTENSE AND
STATIONARY LOW PRESSURE SYSTEM OVER THE PACNW WILL CONTINUE TO PUMP
MOISTURE INTO OUR AREA AND COMBINING THIS WITH DAYTIME HEATING WILL
PRODUCE ISOLATED THUNDERSTORMS THIS AFTERNOON AND EVENING. THE TSRA
COULD BECOME STRONG AND PRODUCE GUSTY WINDS AND HAIL WITH THE BEST
CHANCES OF THIS OCCURRING OVER THE EASTERN ZONES THAT INCLUDES IN
AND AROUND THE BLUE/WALLOWA MOUNTAINS AS WELL AS GRANT COUNTY.
ELSEWHERE SHOWERS WILL CONTINUE DEVELOPING ACROSS THE REGION INTO
THIS EVENING. AS THE LOW DRIFTS INTO NE OREGON LATER TONIGHT
MOISTURE WILL RAP AROUND THIS SYSTEM AND INTO THE EASTERN PORTIONS
OF THE AREA AND MODERATE TO HEAVY RAINFALL IS POSSIBLE WITH UP TO AN
INCH IN SOME LOCATIONS. THE LOW AND THE BULK OF THE MOISTURE DRIFT
NORTH WEDNESDAY MORNING WITH DECREASING CHANCES OF PCPN EXPECTED BUT
THE CLOUDS AND SHOWERS WILL PERSIST INTO WEDNESDAY AFTERNOON. A WEAK
DISTURBANCE WILL NEAR CENTRAL OREGON WEDNESDAY AFTERNOON THAT COULD
PRODUCE AN ISOLD TSRA. OTHERWISE THE BEST CHANCES FOR PCPN SHOULD
OCCUR ALONG THE WA/OR CASCADES WEDNESDAY NIGHT AND THURSDAY.
BY THURSDAY ANOTHER LOW PRESSURE SYSTEM WILL TRACK TO OUR SOUTH BUT
SHOWERS FROM THIS SYSTEM WILL MOVE NORTH AND INTO MOST PORTIONS OF
OUR AREA THURSDAY NIGHT. AFTERNOON TEMPERATURES WILL REMAIN COOL
TOMORROW BEFORE WARMER TEMPERATURES CAN BE EXPECTED THURSDAY.
LONG TERM...FRIDAY THROUGH MONDAY NIGHT...MILD YET UNSETTLED
WEATHER CAN BE EXPECTED FOR THE EXTENDED. A LOW PRESSURE SYSTEM
CENTERED OVER CENTRAL NEVADA WILL CONTINUE TO SPIN UP MOISTURE AND
POSSIBLE THUNDERSTORMS TO THE AREA ON FRIDAY. THIS SYSTEM WILL EXIT
THE AREA FRIDAY NIGHT WITH ANOTHER LOW MOVING TOWARDS THE PACIFIC
COAST ON SATURDAY. THIS LOW IS CURRENTLY FORECAST TO TRACK SOUTH OF
THE CWA TOWARDS THE NORTHERN CALIFORNIA COAST THROUGH THE WEEKEND.
THIS WILL ALLOW FOR MORE MOISTURE AND INSTABILITY TO BE SPUN UP OVER
THE AREA...PROVIDING ANOTHER CHANCE FOR THUNDERSTORMS. THE LOW IS
EXPECTED TO SLOWLY MOVE INLAND AND BE CENTERED OVER THE CA/NV
BOARDER ON MONDAY NIGHT. OVERALL THE AIRMASS SHOULD BE FAIRLY WARM
OVER THE AREA...KEEPING THE TEMPERATURES NEAR TO ABOVE NORMAL.
REASONABLE CLOUD COVER CAN BE EXPECTED AT NIGHT AS WELL...ALLOWING
FOR MILD NIGHTTIME LOWS. WEBER
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 46 62 45 64 / 100 80 10 30
ALW 48 63 46 69 / 100 90 10 30
PSC 52 64 46 70 / 100 90 10 20
YKM 50 59 43 70 / 90 90 40 20
HRI 50 64 44 70 / 100 90 10 30
ELN 47 57 41 70 / 90 90 40 20
RDM 35 60 36 59 / 50 20 30 50
LGD 43 60 41 64 / 100 70 20 30
GCD 39 62 39 65 / 90 20 20 50
DLS 49 65 46 71 / 50 50 30 30
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
&&
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
91/91/91
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1235 AM CDT WED MAY 13 2015
.UPDATE...
ISSUED AT 925 PM CDT TUE MAY 12 2015
STILL A POSSIBILITY OF LLJ/WAA SHOWER/STORM DEVELOPMENT TONIGHT
ALONG THE NORTHERN CWA. THE HRRR MODEL WAS SHOWING SOME DEVELOPMENT
THROUGH THE NIGHT. UNR RADAR WAS ALSO SHOWING SOME SHOWERS MOVING
INTO WESTERN SD THIS EVENING. THUS...LEFT IN THE POPS ACROSS THE
NORTH THROUGH THE NIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY AFTERNOON)
ISSUED AT 323 PM CDT TUE MAY 12 2015
MID LEVEL CLOUDS ARE OCCURRING ACROSS PARTS OF SOUTHWEST NORTH
DAKOTA AND NORTHWEST SOUTH DAKOTA IN RESPONSE TO A WEAK UPPER LEVEL
WAVE. THE LOWER LEVELS ARE PRETTY DRY...AND OBS ARE SHOWING CLOUD
BASES AROUND 7K-8K FT...SO EXPECT THAT VERY LITTLE PRECIP IS
REACHING THE GROUND. DID THROW SPRINKLES INTO THE FORECAST FOR GOOD
MEASURE HOWEVER. LATER TONIGHT...A 40+ KT LLJ DEVELOPS...AND THE
CHANCES FOR SHOWERS AND THUNDERSTORMS INCREASE. STILL ON THE DRY
SIDE HOWEVER...SO NOT EXPECTING MUCH IN THE WAY OF ACCUMULATION WITH
ANY SHOWERS OR STORMS.
WEDNESDAY...A MORE POTENT UPPER LEVEL TROUGH APPROACHES FROM THE
SOUTHWEST. AT THE SURFACE AN INVERTED TROUGH WILL EXTEND FROM
SOUTHWEST SOUTH DAKOTA THROUGH NORTH CENTRAL SOUTH DAKOTA. SURFACE
BASED CONVECTION MAY BE POSSIBLE ALONG THIS BOUNDARY LATE
WEDNESDAY AFTERNOON AS ML CAPE VALUES RISE TO AROUND 1000 J/KG.
0-6 KM SHEAR ISNT OVERLY IMPRESSIVE /AROUND 20 KTS/ AND LCLS ARE
FAIRLY HIGH...BUT CANT RULE OUT A FEW STRONGER PULSE STORMS WITH
LARGE HAIL. THE MAIN FORCING ASSOCIATED WITH THE UPPER TROUGH THEN
SPREADS OVER THE REGION LATE WEDNESDAY NIGHT THROUGH THURSDAY.
HIGH CHANCE TO LIKELY POPS ARE IN THE FORECAST FOR THIS TIME
PERIOD.
.LONG TERM...(THURSDAY EVENING THROUGH TUESDAY)
ISSUED AT 323 PM CDT TUE MAY 12 2015
EXTENDED PERIOD STILL APPEARS TO BE AN ACTIVE ONE WITH SEVERAL
CHANCES FOR RAIN. BEGINNING FRIDAY...FIRST SYSTEM IS ALREADY
APPROACHING THE NORTHERN PLAINS. DURING THE DAYTIME HOURS...MODELS
SUGGEST MAINLY WESTERN AND CENTRAL SD SEEING THE BEST CHANCES.
FRIDAY NIGHT LOOKS TO BE THE BEST CHANCE FOR WIDESPREAD
PRECIPITATION OVER THE FORECAST AREA. MODELS ARE ACTUALLY IN RATHER
GOOD AGREEMENT IN TIMING AND PLACEMENT/COVERAGE OF RAIN SO DID NOT
MAKE MANY CHANGES TO THE LIKELY SUPERBLEND POPS. SATURDAY AND
SATURDAY NIGHT COULD BE QUITE INTERESTING AS SOME BETTER INSTABILITY
AND SHEAR SPREAD NORTHWARD ACROSS THE AREA. MODELS ARE AGAIN IN
PRETTY DECENT AGREEMENT IN SHOWING SHORTWAVE ENERGY MOVING ACROSS
THE AREA WITH SHOWERS AND STORMS DEVELOPING DURING THE AFTERNOON AND
EVENING HOURS SATURDAY. LEFT THE HIGH POPS ALONE THAT SUPERBLEND
GAVE AS THIS LOOKS GOOD FOR NOW. IN REGARDS TO THIS STRONGER WEEKEND
SYSTEM...THERE IS STILL SOME DISAGREEMENT IN THE OVERALL EVOLUTION
AND MOVEMENT OF THE MAIN UPPER LOW HEADING INTO EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1234 AM CDT WED MAY 13 2015
VFR CONDITIONS ARE EXPECTED FOR ALL LOCATIONS THROUGH TONIGHT AND
WEDNESDAY WITH MID AND HIGH LEVEL CLOUDS STREAMING OVER. THERE WILL
BE A FEW HIGH BASED SHOWERS/STORMS POSSIBLY AFFECTING THE LOCATIONS
THROUGH THE NIGHT. OTHERWISE...BREEZY/WINDY SOUTHEAST WINDS ARE
EXPECTED TO CONTINUE THROUGH TONIGHT AND WEDNESDAY. VERY STRONG
WINDS OFF THE SURFACE TO OVER 50 KNOTS WILL BRING SOME LOW LEVEL
WIND SHEAR TO ATY AND ABR TONIGHT. EXPECT SOUTH WINDS AT 15 TO 25
KNOTS WITH GUSTS TO 30 TO 35 KNOTS TO MIX OUT ON WEDNESDAY. ANOTHER
ROUND OF SHOWERS AND THUNDERSTORMS MAY DEVELOP BY WEDNESDAY EVENING
POSSIBLY AFFECTING ALL LOCATIONS.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...MOHR
SHORT TERM...SERR
LONG TERM...TMT
AVIATION...TDK
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
440 AM CDT WED MAY 13 2015
.SHORT TERM (TODAY THROUGH THURSDAY)...THE FORECAST IS NOT EASY.
AS OF WRITING...A THIN AXIS CONTAINING DEEPEST MOISTURE WAS
LOCATED ALONG AND JUST OFFSHORE OF THE MIDDLE TEXAS COAST.
MODEST...BUT GRADUALLY STRENGTHENING...LOW LEVEL MOISTURE
ADVECTION WAS OCCURRING INTO THE AREA OF DEEPER MOISTURE.
THIS...IN ADDITION TO AN APPROACHING H5 VORT MAX...HAS LED TO
SIGNIFICANT SHOWERS AND THUNDERSTORMS PERSISTING OVER THE PAST
SEVERAL HOURS ACROSS THE NEARSHORE WATERS. AFTER COLLABORATION
WITH THE SATELLITE PRECIPITATION ANALYSIS BRANCH ABOUT WHERE HEAVY
RAINFALL POTENTIAL MAY OCCUR...HAVE DECIDED TO EXPAND FLASH FLOOD
WATCH INTO THE NORTHERN COASTAL BEND TO ACCOUNT FOR POTENTIAL OF
DEEPER MOISTURE AXIS SHIFTING NORTHWARD...WHICH COULD LEAD TO
HOURLY RAINFALL RATES OF 1 TO 3 INCHES. ELSEWHERE
INLAND...ISOLATED TO SCATTERED CONVECTION IS GRADUALLY DEVELOPING
IN RESPONSE TO A STRENGTHENING ESE 925MB LLJ. RAP MID LEVEL
HEIGHT ANALYSIS OVERLAID WITH WATER VAPOR IMAGERY INDICATES AN
APPROACHING MID LEVEL S/W TROUGH WHICH SHOULD AID IN CONVECTIVE
DEVELOPMENT ALONG THE RIO GRANDE BY SUNRISE. THE OVERALL FORECAST
FOR TODAY CALLS FOR CONVECTION ALONG THE COAST TO PERSIST AND
BUILD NORTHWARD THROUGH MID MORNING WITH ADDITIONAL CONVECTION
DEVELOPING/EXPANDING IN AREAL COVERAGE ALONG THE RIO GRANDE AND
BEGIN TO SHIFT NE. LOCALLY HEAVY RAINFALL WILL BE POSSIBLE PRETTY
MUCH ANYWHERE TODAY AS PWATS REMAIN HIGH. A STRONG STORM WILL BE
POSSIBLE ACROSS THE REGION GIVEN EXPECTED MLCAPE VALUES AROUND
2000 J/KG AND SUFFICIENT BULK SHEAR VALUES /ESPECIALLY ACROSS NW
COUNTIES/. MAIN MID LEVEL TROUGH AXIS SWINGS THROUGH THE AREA BY
LATE TODAY RESULTING IN DRIER CONDITIONS TONIGHT. CAVEAT IS THAT A
A MINOR S/W TROUGH MAY PUSH ACROSS TONIGHT WHICH MAY LEAD TO
ADDITIONAL CONVECTIVE CHANCES...ESPECIALLY ACROSS SOUTHERN ZONES.
GUIDANCE INDICATES SOME DRIER AIR AT H85 BUILDING INTO THE REGION
ON THURSDAY RESULTING IN LOWER PRECIP CHANCES.
WILL ALLOW RIP CURRENT RISK TO EXPIRE AT 6 AM. A MODERATE RISK OF
RIP CURRENTS WILL EXIST TODAY AND MAY FLIRT WITH THE HIGH RISK
THRESHOLD AGAIN ON THURSDAY.
&&
.LONG TERM (THURSDAY NIGHT THROUGH TUESDAY)...AN UPPER LEVEL
DISTURBANCE WILL MOVE OUT OF MEXICO THURSDAY NIGHT INTO FRIDAY.
THIS WILL LEAD TO CONTINUED CHANCES OF SHOWERS AND STORMS OVER THE
WEST THURSDAY NIGHT...SHIFTING TO THE NORTHERN SECTIONS ON FRIDAY.
RAIN CHANCES MAY TEMPORARILY LOWER ON SATURDAY THE SHORTWAVE
TROUGH PASSES OFF TO THE NORTHEAST. WILL KEEP SOME LOW END 20 POPS
THOUGH WITH LINGERING MOISTURE ACROSS SOUTH TEXAS. ACTIVE WEATHER
PATTERN APPEARS TO RETURN BEGINNING SUNDAY THROUGH THE FIRST PART
OF NEXT WEEK. SOUTHWEST FLOW ALOFT WITH OCCASIONAL UPPER
DISTURBANCES WILL TRAVERSE THE REGION DURING THIS TIME. SUPERBLEND
POPS GENERALLY RANGE FROM 30 TO 50 PERCENT...AND WILL KEEP
OFFICIAL FORECAST SIMILAR TO SUPERBLEND NUMBERS. TEMPERATURES IN
THE 80S WILL BE COMMON THROUGH THE PERIOD...WITH LOWER 90S OVER
THE WESTERN ZONES FRIDAY THROUGH SUNDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 83 74 86 75 84 / 50 30 30 20 30
VICTORIA 81 72 88 73 83 / 60 40 30 20 40
LAREDO 85 72 91 73 90 / 60 20 20 30 30
ALICE 85 72 89 73 86 / 50 20 30 20 30
ROCKPORT 83 76 85 76 80 / 50 30 20 20 30
COTULLA 82 70 89 71 87 / 70 20 20 40 30
KINGSVILLE 86 74 88 75 86 / 50 30 30 20 30
NAVY CORPUS 83 75 84 76 81 / 50 30 20 20 30
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...FLASH FLOOD WATCH UNTIL 3 PM CDT THIS AFTERNOON FOR THE
FOLLOWING ZONES: ARANSAS...BEE...CALHOUN...DUVAL...GOLIAD...
JIM WELLS...LA SALLE...LIVE OAK...MCMULLEN...REFUGIO...
VICTORIA...WEBB.
HIGH RIP CURRENT RISK UNTIL 6 AM CDT EARLY THIS MORNING FOR THE
FOLLOWING ZONES: ARANSAS...CALHOUN...KLEBERG...NUECES.
GM...NONE.
&&
$$
RH/79...SHORT TERM
TB/78...LONG TERM
AREA FORECAST DISCUSSION...UPDATED
NWS BROWNSVILLE TX
244 AM CDT WED MAY 13 2015
.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
&&
.AVIATION...IR SATL IMAGERY INDICATES PLENTY OF MID AND HIGH LEVEL
CLD COVER ADVECTING FROM SW TO NE OVER DEEP SOUTH TEXAS WITH A
PRETTY LARGE CONV COMPLEX BUILDING WEST TOWARDS THE COASTAL BEND
AREA. KBRO RADAR SHOWS QUIET CONDITIONS OVER THE INLAND AREAS OF
DEEP SOUTH TX AND FURTHER WEST AND SOUTH OF THE RIO GRANDE. IF THE
CONV COMPLEX BUILDING WEST TOWARDS THE COASTAL BEND MAINTAINS IT
SPEED AND CURRENT LEVEL OF ORGANIZATION IT SHOULD NOT HAVE ANY
MAJOR IMPACT ON THE RGV AIRPORTS OVER THE NEXT SEVERAL HOURS.
THE LATEST HRRR GUIDANCE SWINGS A COUPLE A ROUNDS OF CONV THROUGH
THE NORTHERN AND WESTERN PORTIONS OF THE BRO CWA LATER THIS
MORNING INTO THIS AFTERNOON. HOWEVER THE MODEL GUIDANCE KEEPS MOST
OF THIS CONV CLEAR OF RGV AIRPORTS THROUGHOUT THE BULK OF THE
CURRENT TAF FORECAST PERIOD. THE MOST RECENT SURFACE OBS SHOW THAT
SOME MVFR CEILINGS ARE MOVING IN OVER THE RGV EARLY THIS MORNING.
EXPECT THE CEILINGS TO THEN TREND MORE TOWARDS VFR LEVELS LATER
TODAY WITH SOME POSSIBLE BRIEF REDUCTIONS TO IFR/MVFR CONDITIONS
IF SOME OF THE ANTICIPATED CONV LATER TODAY MOVES OVER THE RGV
AIRPORTS.
&&
.PREV DISCUSSION... /ISSUED 651 PM CDT TUE MAY 12 2015/
DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
AVIATION...VISIBLE SATELLITE IMAGERY SHOWS LOW CLOUDINESS
CURRENTLY AFFECTING THE AERODROMES WITH SIGNIFICANT CIRRUS FROM
CONVECTION IN NEIGHBORING MEXICO APPROACHING DEEP SOUTH TEXAS AND
THE RIO GRANDE VALLEY FROM THE SOUTHWEST. LOCAL RADAR IS FREE OF
PRECIPITATION ECHOES...AND IN THE WAKE OF MONDAY/S WIDESPREAD
CONVECTION...THE ATMOSPHERE HAS YET TO RECOVER. OVERALL...VFR IS
EXPECTED THROUGH THE OVERNIGHT HOURS WITH LIGHT SURFACE WINDS.
TOMORROW...VFR WILL CONTINUE WITH BREEZY WINDS AND BROKEN SKIES.
DEPENDING ON WHAT HAPPENS CONVECTION-WISE...IF ANYTHING...FOR
TONIGHT...SHOWERS AND THUNDERSTORMS MAY NEED TO BE ADDED TO THE
TAFS BY A FOLLOWING SHIFT FOR TOMORROW.
PREV DISCUSSION... /ISSUED 256 PM CDT TUE MAY 12 2015/
SHORT TERM /NOW THROUGH WEDNESDAY NIGHT/...LARGE THUNDERSTORM
SYSTEM WELL STABILIZED THE LOCAL ATMOSPHERE FOR THE MORNING
HOURS...BUT A FEW SHOWERS HAVE ALREADY BEGUN TO FORM BACK TO THE
WEST THIS AFTERNOON. MOST MODELS SHOW SHOWER ACTIVITY CONTINUING
TO DRIFT GENERALLY NORTHWARD THROUGH THE REST OF THE
AFTERNOON...REMAINING UNCOORDINATED IN NATURE. SOUTHWEST FLOW
ALOFT WILL CONTINUE TO BRING MOISTURE INTO THE REGION ALONG WITH
VARYING ENERGY WAVES CAUGHT IN THE FLOW. THIS WILL HELP PRODUCE
ANOTHER ROUND OF THUNDERSTORM ACTIVITY ON THE MOUNTAINS IN
MEXICO...WHICH WILL THEN DETACH AND DRIFT NE INTO THE RIO GRANDE
PLAINS. ATMOSPHERE IS STILL EXTREMELY MOIST...AND ANY RAINFALL
THAT DOES FALL WILL LIKELY REACH AREAS THAT SAW MORE THAN 5 INCHES
LAST NIGHT. THE FLASH FLOOD WATCH WILL CONTINUE FOR THE COASTAL
COUNTIES THROUGH 8PM AND FOR THE INLAND COUNTIES THROUGH THE NIGHT
INTO TOMORROW MORNING.
LONG TERM /THURSDAY THROUGH MONDAY/...MID LEVEL FLOW WILL BE
CHARACTERIZED BY TROUGHING ACROSS THE WESTERN CONUS AND RIDGING
ACROSS THE EASTERN CONUS. S/W TROUGH FROM THE SHORT TERM PERIOD
WILL BE WELL NORTH OF THE REGION WITH A MUCH STRONGER WAVE COMING
ASHORE ACROSS THE SOUTHWEST PACIFIC COAST. SOUTHWESTERLY FLOW WILL
CONTINUE THROUGH MUCH OF THE PERIOD AND WITH AMPLE MOISTURE AND
WEAK DISTURBANCES MOVING THROUGH THE FLOW...SHOWERS AND STORMS
WILL DEVELOP ACROSS THE HIGHER TERRAIN AND MOVE TOWARDS OUR AREA.
BY THE WEEKEND PWATS LOWER AND WITH A LACK OF GOOD FORCING AND A
SFC FEATURE WILL JUST HAVE ISOLATED SHOWERS AND STORMS. PWATS RAMP
BACK UP LATE SUNDAY AND MONDAY WITH ANOTHER UPPER DISTURBANCE
MOVING ACROSS THE SIERRA MADRES ISOLATED TO SCATTERED CONVECTION
APPEARS PROBABLE. WILL HAVE A SLOW RISE IN TEMPERATURES THROUGH
THE WEEKEND THEN MODERATED SOMEWHAT BY INCREASE IN CLOUDS AND
PRECIPITATION TOWARDS EARLY NEXT WEEK.
MARINE...NOW THROUGH WEDNESDAY NIGHT...SOUTHEAST WINDS WILL
REMAIN ROUGHLY 10 TO 15 KNOTS DURING THE NEXT 36
HOURS...CONTINUING TO PRODUCE LONG FETCH SOUTHEAST WINDS. THIS
FETCH WILL CONTINUE TO PRODUCE SEAS OF 4 TO 7 FEET OFFSHORE
THROUGH THE FORECAST PERIOD. THUNDERSTORM ACTIVITY WILL CONTINUE
TO MOVE ACROSS THE REGION...WITH PERIODS OF EXCESSIVE
RAINFALL...CLOUD TO SFC LIGHTNING AND GUSTY WINDS.
THURSDAY THROUGH SATURDAY...MODERATE SOUTHEAST WINDS WILL PREVAIL
ACROSS THE LOWER TEXAS COASTAL WATERS THIS PERIOD. SMALL CRAFT
EXERCISE CAUTION CONDITIONS APPEAR POSSIBLE SATURDAY ACROSS THE
LAGUNA MADRE AND LATER SATURDAY ACROSS THE GULF WATERS. SMALL
CRAFT ADVISORIES APPEAR POSSIBLE JUST AFTER THIS PERIOD SATURDAY
NIGHT INTO SUNDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL 84 76 86 77 / 30 40 30 20
BROWNSVILLE 85 76 87 76 / 30 40 30 20
HARLINGEN 86 75 89 76 / 30 50 30 20
MCALLEN 86 75 89 76 / 30 60 30 20
RIO GRANDE CITY 86 73 89 74 / 40 60 40 30
SOUTH PADRE ISLAND 82 76 82 77 / 30 40 30 20
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...FLASH FLOOD WATCH UNTIL NOON CDT TODAY FOR TXZ248>250-252-253.
GM...NONE.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
SHORT TERM...60
LONG TERM...63
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
916 AM MDT WED MAY 13 2015
.UPDATE...
NO UPDATE PLANNED THIS MORNING. HRRR/WRF INITIALIZED WELL WITH
MORNING PRECIPITATION WHICH WAS LOCATED OVER N MT/E WY. MODELS
SHOWED CONVECTION DEVELOPING OVER THE NE BIG HORNS/PRYORS AND
SPREADING NORTHWARD WITH TIME. OTHER CONVECTION WILL MOVE N FROM E
WY INTO THE AREA. NOT SURE HOW MUCH DEVELOPMENT WILL OCCUR W OF
KBIL THROUGH 18Z...BUT WILL LEAVE THE SLIGHT CHANCE ALONE FOR NOW.
SREF AND RAP SOUNDINGS SHOWED SURFACE CAPES AROUND 500 J/KG ACROSS
MUCH OF THE AREA THIS AFTERNOON AND EVENING...WITH CAPES POSSIBLY
REACHING AS HIGH AS 1000 J/KG. EFFECTIVE BRN SHEAR WILL BE ON THE
ORDER OF 30 TO 40 KT WHICH IS MARGINAL FOR SEVERE STORMS. GIVEN
THE SOMEWHAT HIGH CAPES AND MARGINAL SHEAR...EXPECT ISOLATED
STRONG TO SEVERE STORMS OVER THE AREA THIS AFTERNOON AND EVENING.
HAIL UP TO AN INCH IN DIAMETER WILL BE A THREAT ALONG WITH GUSTY
WINDS...DUE TO INVERTED-V NATURE OF SOUNDINGS. LIFT FOR THE
CONVECTION WILL BE IN THE FORM OF WEAK WAVES...JET
DIVERGENCE...DIFFLUENCE OVER THE W AND TOPOGRAPHY. SLIGHT CHANCE
FOR THUNDERSTORMS WILL LINGER LATE TONIGHT DUE TO STEEP MID-UPPER
LEVEL LAPSE RATES.
MORE SHOWERS AND STORMS ARE EXPECTED THU UNDER AN ACTIVE DIFFLUENT
FLOW. CAPES AND SHEAR WILL BE SIMILAR TO TODAY/S VALUES. ARTHUR
&&
.SHORT TERM...VALID FOR TDY AND THU...
WEATHER CONTINUES TO BECOME MORE ACTIVE AS THE WEEK PROGRESSES AS
A STRONG UPPER LOW OFF THE CALIFORNIA COAST BEGINS ITS APPROACH
ON THE ROCKIES BY LATE IN THE WEEK. ALREADY SEEING SOME SHOWERS
FEEDING NORTH INTO WESTERN AREAS IN MOIST SOUTHWEST FLOW EARLY
THIS MORNING. SO HAVE INCLUDED ISOLATED SHOWERS WEST OF BILLINGS
THIS MORNING. DAYTIME HEATING WILL RESULT IN INCREASED INSTABILITY
BY LATE IN THE DAY...ESPECIALLY ALONG A BOUNDARY/INVERTED TROUGH
FROM ABOUT HARLOWTON TO BILLINGS TO SHERIDAN WHERE HIGHEST CAPES
WERE POOLING. EXPECT THUNDERSTORMS TO DEVELOP IN THIS REGION AIDED
BY AN APPROACHING SHORT WAVE. LOCAL STRONG STORMS LOOK POSSIBLE.
THE STORM PREDICTION CENTER HAS OUTLINED THIS AREA FOR ISOLATED
STORMS CAPABLE OF PRODUCING HAIL CLOSE TO THE ONE INCH SEVERE
LEVELS AND GUSTY WINDS. THIS ACTIVITY EXPECTED TO SHIFT NORTHEAST
INTO THE PLAINS OVERNIGHT...ALTHOUGH WEAKER...BUT KEEPING
PRECIPITATION CHANCES GOING.
FOR THURSDAY...MUCH OF THE SAME EXPECTED...BUT BECOMING EVEN MORE
WIDESPREAD. MORE INSTABILITY TO WORK WITH AGAIN ALONG AND WEST OF
A CORRIDOR FROM HARLOWTON TO BILLINGS TO SHERIDAN. DAYTIME HEATING
WILL AGAIN INCREASE THUNDERSTORM THREAT AND AIDED BY AN INCREASING
DIFFLUENT UPPER FLOW. THIS ACTIVITY AGAIN WILL BE HANGING ON
THROUGH THURSDAY NIGHT AS GOOD SOUTHEASTERLY LOW LEVEL JET
CONTINUES TO FEED MOISTURE INTO THE REGION. FRIEDERS
.LONG TERM...VALID FOR FRI...SAT...SUN...MON...TUE...
MODELS REMAIN IN RELATIVELY GOOD AGREEMENT...WITH REGARD TO
EXTENDED PERIOD OF COOL AND UNSETTLED WEATHER. MODELS ALSO
CONTINUE TO HAVE SOME TIMING AND MINOR TRACK ISSUES...BUT HAVE
ACTUALLY RETURNED TO A DEPICTION OF EVENTS THAT IS VERY SIMILAR TO
RUNS OF 48HRS AGO.
DIFFLUENT FLOW ALOFT IS PROGGED TO PERSIST OVER OUR FORECAST
AREA AHEAD OF THE STRONG PACIFIC LOW PUSHING EASTWARD. THIS WILL
COMBINE WITH A SFC LOW SETTING UP ACROSS NORTHERN WYOMING. THIS
SHOULD RESULT IN A BROAD AREA OF PRECIP ACROSS THE
REGION...THROUGH MUCH OF THE DAY FRIDAY. THE UPPER LEVEL LOW MOVES
NORTHEAST TO SOUTHEAST MONTANA/NORTHEAST WYOMING DURING
SATURDAY...AND BECOMES STACKED WITH SFC LOW...STILL ANCHORED OVER
SOUTHEAST MONTANA...RESULTING IN NUMEROUS WRAP-AROUND TYPE
SHOWERS. MODELS DIVERGE ON TIMING OF PUSHING SYSTEM
EASTWARD...WITH GFS CLEARING SYSTEM EAST INTO THE DAKOTAS ON
SUNDAY MORNING...WHILE THE ECMWF KEEP PRECIP IN THE AREA UNTIL
SUNDAY NIGHT. ECMWF HAS BEEN MORE CONSISTENT OF MODELS THUS
FAR...SO HAVE KEPT HIGH CHANCE POPS IN PLACE THROUGH SUNDAY
AFTERNOON. THERE APPEARS TO BE A BIT OF A BREAK IN PRECIP CHANCES
SUNDAY NIGHT INTO MONDAY...BUT MODELS ARE QUICK TO BRING THE NEXT
TROF INTO THE REGION...WITH SOUTHWEST FLOW ALOFT IMPACTING THE
MOUNTAINS...AND DIFFLUENT FLOW ALOFT QUICKLY SETTING UP OVER THE
REGION MONDAY MORNING. MODELS AGAIN VARY ON HOW THIS SYSTEM CROSS
THE REGION. THE PATH FAVORED BY THE GFS IS VERY SIMILAR TO THE
WEEKEND SYSTEM...WITH CUT OFF LOW SLIDING INTO SOUTHEAST
MONTANA...AND EXITING INTO THE DAKOTAS ON WEDNESDAY AFTERNOON.
ECMWF TAKES A LITTLE MORE TIME FORMING THE CUT OFF LOW...KEEPING
MUCH OF THE PRECIP ALONG THE MT/WY BORDER UNTIL TUESDAY NIGHT. CUT
OFF LOW FORMS TUESDAY NIGHT...AND CATCHES UP TO THE GFS WEDNESDAY
MORNING...SHIFTING THE LOW INTO THE DAKOTAS THAT AFTERNOON. HAVE
CARRIED POPS THAT ARE WELL ABOVE CLIMO THROUGH THIS PERIOD...FROM
MONDAY EVENING THROUGH WEDNESDAY...WITH HIGHEST POPS ACROSS THE
SOUTHERN TIER OF THE CWA.
AS FOR TEMPS...EXPECT TO SEE HIGHS BELOW SEASONAL AVERAGE
THROUGHOUT THE PERIOD. TRENDED TEMPERATURES SLIGHTLY COOLER
THROUGHOUT THE PERIOD...TOWARD THE ECMWF. AGAIN THIS HAS BEEN A
BIT MORE CONSISTENT...AND GFS SEEMS TO BE TRENDING A BIT COOLER AS
WELL. AAG
&&
.AVIATION...
EXPECT A PARTLY TO MOSTLY CLOUDY DAY TODAY WITH ISOLATED SHOWERS
THIS MORNING. A BETTER CHANCE FOR SHOWERS AND THUNDERSTORMS CAN BE
EXPECTED THIS AFTERNOON ALONG THE MONTANA/WYOMING BORDER...AS WELL
AS ALONG AND WEST OF A KSHR-KBIL-ROUNDUP LINE. MVFR TO IFR
CONDITIONS WILL BE POSSIBLE IN ANY THUNDERSTORM ACTIVITY.
OTHERWISE...VFR CONDITIONS WILL PREVAIL THROUGHOUT THE DAY. HOOLEY
&&
.PRELIMINARY POINT TEMP/POPS...
TDY THU FRI SAT SUN MON TUE
-------------------------------------------------------
BIL 070 046/066 046/058 045/055 043/055 037/060 038/059
2/T 44/T 56/T 66/T 66/W 33/W 34/W
LVM 068 040/064 042/057 040/054 041/054 033/060 034/059
2/T 35/T 56/T 67/T 66/W 33/W 33/W
HDN 073 045/069 046/060 045/058 044/056 035/063 038/061
1/B 53/T 56/T 67/T 76/W 32/W 24/W
MLS 071 046/067 046/062 047/060 044/054 036/061 038/060
1/B 53/T 46/T 88/T 76/W 22/W 23/W
4BQ 070 047/066 047/060 047/058 045/052 034/058 037/059
1/B 32/T 46/T 77/T 76/W 22/W 34/W
BHK 065 043/063 043/059 044/058 044/055 031/060 036/058
1/B 53/T 16/T 88/T 77/W 22/W 24/W
SHR 068 041/067 043/060 042/056 041/052 032/058 035/057
3/T 43/T 56/T 67/T 76/W 23/W 45/W
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
625 AM CDT WED MAY 13 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 320 AM CDT WED MAY 13 2015
TODAY AND TONIGHT...THE SUBTROPICAL DISTURBANCE OFF OF BAJA MEXICO
YESTERDAY HAS MOVED NORTH INTO NEW MEXICO THIS MORNING. THE MODELS
LIFT THIS DISTURBANCE THROUGH THE CNTL PLAINS TODAY AND TONIGHT.
TWO CONVECTIVE ITEMS OF INTEREST HAVE BEEN IDENTIFIED AS THE
DISTURBANCE MOVES THRU WRN AND NCNTL NEBRASKA LATE THIS AFTN AND
TONIGHT. ONE IS A ROUND OF CONVECTION THAT SHOULD FIRE ON THE
COLORADO FRONT RANGE AND LARAMIE RANGE AROUND 18Z-21Z. THE STEERING
WINDS ALOFT CARRY THIS CONVECTION NNE THROUGH THE NEB PANHANDLE
AFFECTING AREAS MAINLY ALONG AND WEST OF HIGHWAY 61. MEANWHILE THE
SREF AND GEF SUGGEST A SECOND HEAVIER RAIN CENTER WILL MOVE ACROSS
WCNTL KS AND THROUGH SCNTL/ERN NEB EXITING AROUND 12Z.
THE QUESTION THOUGH IS HOW FAR WEST THE SECOND RAIN CENTER WILL
TRACK GIVEN THAT THE MODELS TREND WEST WITH RETURN MOISTURE. THE RAP
AND NAM PROVIDE AN ANSWER AS THEY ARE FARTHEST WEST AT 00Z WITH PWAT
NEAR 1.25 INCHES AND BACKED 850MB NEAR PAMPA TX. THIS MOISTURE
SHOULD MOVE NORTH-NORTHEAST DURING THE EVENING PRESENTING THE
POTENTIAL FOR HEAVY RAIN...0.5 TO 1 INCH EAST OF HIGHWAY 83 ACROSS
CUSTER COUNTY AND NORTHEAST. THE 1 INCH QPF IS SPECULATIVE. THE
MOISTURE IS VERY DEEP AND TRANSPORT EXTENDS TO 500 MB OR HIGHER AND
IS QUITE STRONG BELOW 700MB. WE WILL SEE WHAT HAPPENS TONIGHT. IF
SOME SORT OF LOW LEVEL BOUNDARY OR FOCUS DEVELOPS...NOT SHOWN BY
THE MODELS ATTM...THAN THE 1 INCH QPF COULD VERIFY SOMEWHERE. THE
QPF FORECAST FOLLOWS THE SREF AND NAM FOR UP TO 1/2 INCH OF RAIN IN
THE EAST AND UP TO 1/3 OF AN INCH WEST OF HIGHWAY 61.
THE "HURRICANE" CONTINUES TODAY. THE RAP13 500M AGL WINDS INCREASE
TO 25 TO 30 KTS WHICH IS 25 TO 30 MPH NEAR THE SFC WITH GUSTS TO 40
MPH IN OPEN AREAS.
THE TEMPERATURE FORECAST TODAY FOLLOWS THE WARM SIDE OF THE MODEL
CLUSTER FOR HIGHS IN THE LOW TO MID 70S. THE RAP SHOWS 80 NEAR
VALENTINE AND 76 AT NORTH PLATTE. MID LEVEL CLOUDINESS SHOULD INVADE
THE REGION HOLDING HIGHS DOWN BELOW THE RAP FORECAST. LOWS TONIGHT
FALL INTO THE UPPER 40S TO MID 50S. THE NAM SHOWS OVERCAST SKIES AT
09Z WITH A CLEARING LINE NEAR HIGHWAY 61 AT 12Z EARLY THURSDAY
MORNING.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 320 AM CDT WED MAY 13 2015
THE LARGE SCALE UPPER LEVEL PATTERN PERSISTS THROUGH THE END OF THE
WEEK AND INTO EARLY NEXT WEEK...DEFINED BY A DEEP TROUGH WITH
SEVERAL EMBEDDED PV ANOMALIES IN THE WESTERN CONUS AND BROAD
ANTICYCLONIC FLOW TO THE EAST. THIS PUTS THE CENTRAL CONUS IN A
FAVORABLE SYNOPTIC SETUP FOR POLEWARD MOISTURE TRANSPORT AND
RECURRING CHANCES FOR PRECIPITATION...INCLUDING THE POTENTIAL FOR
SEVERE WEATHER LATER THIS WEEK.
THURSDAY BEGINS WITH INHERITED MORNING POPS AS A SHORTWAVE DEPARTS
THE CENTRAL PLAINS AND MOVES INTO THE UPPER MS VALLEY. MODELS ARE IN
AGREEMENT WITH UPPER LEVEL HEIGHT RISES AND GRADUALLY CLEARING SKIES
BY THE AFTERNOON...SO TRENDED HIGH TEMPERATURES UP A FEW DEGREES TO
FOLLOW GUIDANCE. SFC WINDS WILL FINALLY EASE UP FOR A DAY DUE TO
WEAK PRESSURE TENANCIES OVER THE CWA...GENERALLY EXPECTING WINDS
AROUND 10 KTS.
POPS ARE QUICK TO MOVE BACK INTO THE FORECAST LATE THURSDAY AS THE
NEXT SHORTWAVE TROUGH ENTERS THE DESERT SOUTHWEST AND SWINGS OUT
TOWARD THE CENTRAL PLAINS. INCREASING DPVA ALOFT WILL PROMOTE A
DEEPENING LEE SIDE SFC TROUGH OVER EASTERN COLORADO AND THE SLOW
NORTHWARD PROGRESSION OF A WARM FRONT INTO NORTHERN KS. DEEP LAYER
MOISTURE PROFILE WILL BECOME INCREASINGLY FAVORABLE FOR
PRECIPITATION DUE TO EASTERLY UPSLOPE WINDS...AND A MID-LEVEL
SUBTROPICAL PLUME OFF THE BAJA TRANSPORTS BETTER MOISTURE ALOFT.
SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP AFTER DARK IN AN
AREA OF ISENTROPIC ASCENT NORTH OF THE WARM FRONT. THE CONVECTION
SHOULD FOLLOW THE WARM FRONT NORTHWARD INTO SOUTHERN SD EARLY
FRIDAY.
SEVERE WEATHER THREAT INCREASES FRIDAY AFTERNOON AND EVENING WITH
THE NEXT ROUND OF THUNDERSTORM ACTIVITY. SFC DEWPOINTS INCREASE TO
AROUND 60F INVOF A SHARPENING DRY LINE OVER WESTERN KS AND SOUTHWEST
NEBRASKA AND SOUTH OF THE WARM FRONT IN SOUTHERN SD. THE ATMOSPHERE
WILL BECOME QUITE UNSTABLE BY THE AFTERNOON AS MID LEVEL LAPSE RATES
STEEPEN AND SFC TEMPS WARM. THUNDERSTORMS SHOULD REFIRE ALONG THE
DRYLINE DURING THE AFTERNOON AND EVENING AS THE DRYLINE SURGES
NORTHEAST. STORMS WILL HAVE THE POTENTIAL TO BECOME SUPERCELLULAR IN
AN ENVIRONMENT CHARACTERIZED BY UP TO 2000 J/KG ML CAPE AND 40-45
KTS OF DEEP LAYER SHEAR. LARGE HAIL AND DAMAGING WIND WILL BE THE
PRIMARY THREATS...BUT LOW LEVEL SFC SHEAR PROFILES FAVOR ELONGATED
HODOGRAPHS AND THE POTENTIAL FOR A FEW TORNADOES.
THUNDERSTORMS AND THE THREAT FOR SEVERE WEATHER REDEVELOP SATURDAY
AS THE LARGE UPPER LEVEL LOW EJECTS TOWARD THE CENTRAL PLAINS. AT
THIS TIME THE AREA OF CONCERN IS GENERALLY EAST OF A SFC TROUGH
MOVING INTO CENTRAL AND EASTERN NEBRASKA. THE EARLY PART OF NEXT
WEEK LOOKS DRIER AS THE UPPER LOW KICKS NORTHEAST AND A RIDGE BUILDS
INTO THE CENTRAL CONUS. HOWEVER MODELS ARE QUICK TO BRING ANOTHER
TROUGH INTO THE ROCKIES BY TUESDAY...BRINGING WITH IT MORE CHANCES
FOR SHOWERS AND THUNDERSTORMS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 625 AM CDT WED MAY 13 2015
VFR IS EXPECTED THROUGH 21Z THIS AFTN. THEREAFTER...THE UPPER
LEVEL DISTURBANCE ACROSS NEW MEXICO WILL SPREAD RAIN...SHRA AND
ISOLD TSTMS INTO THE FCST AREA FROM SOUTH TO NORTH. MVFR/IFR IS
EXPECTED IN RAIN AND LOW CIGS THIS EVENING. THE SREF INDICATES A
HIGH PROBABILITY OF IFR CIGS ALONG AND EAST OF HIGHWAY 61 FROM
06Z-12Z.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...MARTIN
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
953 AM EDT WED MAY 13 2015
.SYNOPSIS...
DRIER AIR WILL SPREAD INTO THE REGION TODAY AND THURSDAY WITH
SLIGHT COOLING TONIGHT. HIGH PRESSURE FROM THE GREAT LAKES WILL
MOVE OFFSHORE BEGINNING FRIDAY...BRINGING A GRADUAL INCREASE IN
HUMIDITY AND THUNDERSTORM DEVELOPMENT THROUGH THE WEEKEND INTO
NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 952 AM WEDNESDAY...KLTX VAD WIND PROFILE REGISTERING 3000
FOOT THICK NORTH FLOW ACROSS THE REGION PRESENTLY IN WAKE OF A
COLD FRONT WHICH HAS MIGRATED SOUTH AND EAST OF THE AREA. A BAND
OF MIDDLE AND HIGH CLOUDS FROM 12 KFT UPWARD ARE TRAVERSING OUR
SKIES AND WILL DO SO THROUGH MORNING WITH AN UPTICK IN SUNSHINE
MINUTES ANTICIPATED THIS AFTERNOON. COOLING BEHIND THE FRONT WILL
OCCUR MAINLY TONIGHT AS THE GREAT LAKES HIGH BEGINS TO FALL TOWARD
THE MID-ATLANTIC. DESCENDING DEWPOINTS ON TAP WILL EVACUATE ANY
VESTIGES OF MUGGINESS LOITERING ACROSS THE CAROLINAS. COMFORTABLY
WARM MAXIMUMS TODAY SHOULD RISE TO 80-84 MOST INLAND LOCALITIES TO
76-79 ALONG THE COAST. THE BRUNSWICK COAST MAY GO WARMER IN THE
NEAR DIRECT OFFSHORE WIND REGIME.
THIS EVENING WINDOW-OPEN TYPE CONDITIONS AS TEMPERATURES COOL TO
70 AND BELOW AFTER THE SUN HAS SUNK BELOW THE HORIZON. COOLING
WILL BRING MINIMUMS INTO DAYBREAK THURSDAY INTO THE MIDDLE 50S
WELL INLAND TO THE UPPER 50S COASTAL INTERIOR TO THE LOW 60S
COASTAL ZONES AMID A NE WIND FLOW.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM WEDNESDAY...HIGH PRESSURE WILL SETTLE DOWN OVER THE
CAROLINAS FROM THE NORTH AS MID TO UPPER RIDGE ALIGNS ITSELF UP
THE EAST COAST THURS INTO FRI. OVERALL EXPECT A RAIN FREE PERIOD
WITH PLENTY OF DRY AIR AND SUBSIDENCE THROUGH THE MID LEVELS OF
THE ATMOSPHERE. MAY SEE SOME FLAT CU DEVELOPING WITH HEATING OF
THE DAY AIDED BY SOME CONVERGENCE ALONG SEA BREEZE BUT STRONG
SUBSIDENCE INVERSION WILL NOT ALLOW MUCH DEPTH TO ANY CU. ALTHOUGH
SUNSHINE SHOULD BE QUITE PLENTIFUL THROUGH THE PERIOD...SOME
HIGHER LEVEL CLOUDS WILL SPREAD INTO THE CAROLINAS OVER THE RIDGE
AS IT SLIPS EAST...ESPECIALLY TOWARD THE END OF THE FRIDAY. THE
CENTER OF THE SFC HIGH WILL SHIFT FURTHER EAST ALSO...OFF THE MID
ATLANTIC COAST BY LATE FRI. THEREFORE DRIER NORTHERLY FLOW WILL
SHIFT TO A GREATER ON SHORE TO S-SE MOISTER RETURN FLOW THROUGH
FRI NIGHT INTO THE WEEKEND AND AIR MASS WILL BEGIN TO MODIFY.
AN OVERALL DRY AIR MASS IN PLACE WILL PRODUCE GREAT DIURNAL
SWINGS WITH LOWER DEWPOINTS DOWN CLOSE TO 50 ALLOWING OVERNIGHT
TEMPS TO DROP OFF QUICKLY DOWN TO THE 50S UNDER MAINLY CLEAR SKIES
AND LIGHT TO CALM WINDS. AFTER A RELATIVELY COOLER START TO THE
DAYS...TEMPS WILL RECOVER TO NEAR SEASONABLE VALUES UNDER MAY
SUNSHINE...INTO THE UPPER 70S MOST PLACES.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 300 AM WEDNESDAY...MID TO UPPER RIDGE WILL SHIFT A LITTLE
BUT OVERALL WILL CONTINUE TO HOLD ON UP THROUGH THE
SOUTHEAST...PRODUCING SUBSIDENCE OVER THE AREA. THE SFC HIGH WILL
CONTINUE TO SLIP FARTHER EAST WHICH WILL PRODUCE A GREATER
SOUTHERLY RETURN FLOW OF MOISTURE WITH DEWPOINT TEMPS REACHING
BACK UP INTO AND THROUGH THE 60S DURING THE WEEKEND INTO EARLY
NEXT WEEK. SOME MID TO HIGH CLOUDS WILL CONTINUE TO RIDE THE COLD
FRONT RUNS FROM NEAR JACKSONVILLE NC TO NEAR WHITEVILLE TO SOUTH
OF FLORENCE SC. THIS IS STILL SLOWER THAN ANY MODEL SHOWED JUST
FIVE HOURS AGO...BUT IT APPEARS THE LATEST HRRR MODEL HAS A
REASONABLE HANDLE ON THE MOVEMENT OF THIS FEATURE OVER THE NEXT
FEW HOURS. THE 00Z GFS APPEARS TO HAVE HAD PROBLEMS THIS MORNING
WITH A TOO-RAPID FRONTAL PASSAGE AND ODD WIND DIRECTIONS
THROUGHOUT THE DAY COMPARED TO THE REST OF THE MODELS. FOR WINDS
AND TEMPERATURES I HAVE STAYED CLOSER THE 00Z NAM AS A RESULT.
&&
.AVIATION /13Z WEDNESDAY THROUGH SUNDAY/...
AS OF 12Z...VFR EXPECTED THROUGH THIS TAF VALID PERIOD. KLTX
VAD WIND PROFILE INDICATES N WINDS JUST OFF THE SURFACE SO THE
COLD FRONT SOUTH OF KMYR WITHIN HE NEXT HOUR OR TWO. IT ALSO
INDICATES A SMATTERING MID CLOUD LAYERS WITH A MORE PERSISTENT
CLOUD DECK 18K-20K.
WINDS WILL BE N-NE THIS MORNING BECOMING E AT THE COASTAL
TERMINALS IN THE AFTERNOON. MID/UPPER CLOUDS WILL MOVE OFF IN THE
AFTERNOON AS A FEW/SCT LOW LEVEL CU DEVELOPS. UPPER CLOUDS RETURN
IN THE LATE EVENING AS WINDS BECOME NE FOR THE OVERNIGHT PERIOD.
NO FOG EXPECTED.
EXTENDED OUTLOOK...VFR. ISOLATED SHOWERS FRIDAY...BECOMING SCATTERED
SAT AND SUN. BETTER CHANCES FOR CONVECTION MON.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 952 AM WEDNESDAY...MODERATE N WINDS SKIPPING ACROSS THE
WATERS BUT NO ADVISORIES OR EXERCISE CAUTION STATEMENTS ARE
PLANNED. GUSTS TO 20 KT CANNOT BE RULED OUT BRIEFLY THIS MORNING
IN THIS INITIAL SURGE...AND AGAIN IN THE PRE-DAWN THURSDAY AS
GREAT LAKES HIGH PRESSURE MOVES TOWARD OUR COAST. SEAS 2 TO 4 FEET
OVERALL WITH DOMINANT PERIODS AROUND 6 SECONDS. NO TSTMS OR
RESTRICTIONS TO VISIBILITY EXPECTED THROUGH TONIGHT. WINDS WILL
TEND TO NE TONIGHT 10-15 KT...THEN GUSTS TO 20 NEAR DAYBREAK.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM WEDNESDAY...HIGH PRESSURE BUILDING DOWN FROM THE
NORTH WILL SHIFT EAST THROUGH THE PERIOD EVENTUALLY SHIFTING OFF
THE MID ATLANTIC COAST ON FRI. NORTHEASTERLY FLOW UP TO 15 KTS ON
THE FRONT END WILL LIGHTEN AND VEER AROUND BECOMING MORE NORTHEAST
TO EAST THROUGH THURS AND THEN E-SE FRI NIGHT INTO THE WEEKEND.
SEAS WILL BASICALLY REMAIN IN THE 2 TO 4 FT RANGE.
.LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 300 AM WEDNESDAY...HIGH PRESSURE WILL SHIFT OFFSHORE EARLY
IN THE WEEKEND PRODUCING A SOUTHEASTERLY ON SHORE FLOW LESS THAN
15 KTS. A SEA BREEZE WILL DEVELOP EACH AFTERNOON ADDING TO THE SE
PUSH AND PRODUCING GUSTY ON SHORE WINDS AND SOME CHOP IN THE NEAR
SHORE WATERS EACH AFTERNOON. OVERALL EXPECT SEAS IN THE 2 TO 4 FT
RANGE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...MJC
SHORT TERM...RGZ
LONG TERM...RGZ
AVIATION...MRR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
754 AM EDT WED MAY 13 2015
.SYNOPSIS...
LESS HUMID AIR WILL ARRIVE TODAY AND SHOULD LAST INTO EARLY FRIDAY AS
HIGH PRESSURE BUILDS DOWN FROM THE NORTH. THE LATTER PART OF THE
WEEK AND WEEKEND WILL FEATURE A GRADUAL INCREASE IN HUMIDITY AND
THUNDERSTORM CHANCES AS THE HIGH MOVES OFF THE COAST.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 645 AM WEDNESDAY...THE COLD FRONT RUNS FROM NEAR JACKSONVILLE
NC TO NEAR WHITEVILLE TO SOUTH OF FLORENCE SC. THIS IS STILL SLOWER
THAN ANY MODEL SHOWED JUST FIVE HOURS AGO...BUT IT APPEARS THE
LATEST HRRR MODEL HAS A REASONABLE HANDLE ON THE MOVEMENT OF THIS
FEATURE OVER THE NEXT FEW HOURS. THE 00Z GFS APPEARS TO HAVE HAD
PROBLEMS THIS MORNING WITH A TOO-RAPID FRONTAL PASSAGE AND ODD WIND
DIRECTIONS THROUGHOUT THE DAY COMPARED TO THE REST OF THE MODELS.
FOR WINDS AND TEMPERATURES I HAVE STAYED CLOSER THE 00Z NAM AS A
RESULT.
SHOWER CHANCES ARE QUITE LOW THROUGH THE MORNING. FORECAST SOUNDINGS
SHOW A SMALL REGION OF CONDITIONAL INSTABILITY BASED ABOVE THE
SURFACE WHICH COULD GENERATE AN ISOLATED SHOWER UP THROUGH THE TIME
OF FRONTAL PASSAGE. HOWEVER GIVEN POOR FORCING AND INCREASING
LIMITED VERTICAL MOISTURE...ODDS OF DEVELOPING SHOWERS ARE LESS THAN
10 PERCENT...AND WILL NOT BE MENTIONED IN THE FORECAST.
CONSIDERABLE CIRRUS CLOUDINESS WILL HANG AROUND THROUGH THE MORNING.
GLANCING OUT IN THE NWS OFFICE PARKING LOT THE CLOUDS ARE FAIRLY
OPAQUE BUT HAVE ENOUGH BREAKS AND THIN SPOTS TO LET ENOUGH SUN
THROUGH TO BOOST TEMPERATURES INTO THE UPPER 70S BY NOON. NEARLY
FULL SUNSHINE SHOULD DEVELOP THIS AFTERNOON AS THE CIRRUS ADVECTS
OFFSHORE...AND HIGHS SHOULD REACH 79-84 AWAY FROM THE BEACHES.
LINEAR MOTION EXTRAPOLATION ON THE BACK EDGE OF THE CLOUDS BRINGS IT
TO FLORENCE AROUND NOON...AND WILMINGTON AROUND 2 PM.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM WEDNESDAY...HIGH PRESSURE WILL SETTLE DOWN OVER THE
CAROLINAS FROM THE NORTH AS MID TO UPPER RIDGE ALIGNS ITSELF UP
THE EAST COAST THURS INTO FRI. OVERALL EXPECT A RAIN FREE PERIOD
WITH PLENTY OF DRY AIR AND SUBSIDENCE THROUGH THE MID LEVELS OF
THE ATMOSPHERE. MAY SEE SOME FLAT CU DEVELOPING WITH HEATING OF
THE DAY AIDED BY SOME CONVERGENCE ALONG SEA BREEZE BUT STRONG
SUBSIDENCE INVERSION WILL NOT ALLOW MUCH DEPTH TO ANY CU. ALTHOUGH
SUNSHINE SHOULD BE QUITE PLENTIFUL THROUGH THE PERIOD...SOME
HIGHER LEVEL CLOUDS WILL SPREAD INTO THE CAROLINAS OVER THE RIDGE
AS IT SLIPS EAST...ESPECIALLY TOWARD THE END OF THE FRIDAY. THE
CENTER OF THE SFC HIGH WILL SHIFT FURTHER EAST ALSO...OFF THE MID
ATLANTIC COAST BY LATE FRI. THEREFORE DRIER NORTHERLY FLOW WILL
SHIFT TO A GREATER ON SHORE TO S-SE MOISTER RETURN FLOW THROUGH
FRI NIGHT INTO THE WEEKEND AND AIR MASS WILL BEGIN TO MODIFY.
AN OVERALL DRY AIR MASS IN PLACE WILL PRODUCE GREAT DIURNAL
SWINGS WITH LOWER DEWPOINTS DOWN CLOSE TO 50 ALLOWING OVERNIGHT
TEMPS TO DROP OFF QUICKLY DOWN TO THE 50S UNDER MAINLY CLEAR SKIES
AND LIGHT TO CALM WINDS. AFTER A RELATIVELY COOLER START TO THE
DAYS...TEMPS WILL RECOVER TO NEAR SEASONABLE VALUES UNDER MAY
SUNSHINE...INTO THE UPPER 70S MOST PLACES.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 300 AM WEDNESDAY...MID TO UPPER RIDGE WILL SHIFT A LITTLE
BUT OVERALL WILL CONTINUE TO HOLD ON UP THROUGH THE
SOUTHEAST...PRODUCING SUBSIDENCE OVER THE AREA. THE SFC HIGH WILL
CONTINUE TO SLIP FARTHER EAST WHICH WILL PRODUCE A GREATER
SOUTHERLY RETURN FLOW OF MOISTURE WITH DEWPOINT TEMPS REACHING
BACK UP INTO AND THROUGH THE 60S DURING THE WEEKEND INTO EARLY
NEXT WEEK. SOME MID TO HIGH CLOUDS WILL CONTINUE TO RIDE OVER THE
RIDGE INTO THE AREA BUT OVERALL EXPECT A GOOD DEAL OF SUNSHINE
WITH AFTN TEMPS REACHING CLOSER TO SEASONABLE VALUES THROUGH THE
WEEKEND AND THEN ABOVE NORMAL AS HIGHER DEWPOINTS KEEP OVERNIGHT
LOWS IN THE 60S SAT NIGHT ONWARD. TEMPS DURING THE DAY WILL REACH
UP INTO THE 80S AS H5 HEIGHTS AND 850 TEMPS REMAIN ON RISING TREND
THROUGH EARLY NEXT WEEK. SUBSIDENCE ALOFT SHOULD ONLY ALLOW FOR
LOCALIZED CONVECTION TO DEVELOP MAINLY ASSOCIATED WITH THE SEA
BREEZE THROUGH MONDAY. BY TUES...THE RIDGE FLATTENS AND COLD FRONT
APPROACHES THE AREA WITH THE BEST CHC OF PCP COMING MID WEEK NEXT
WEEK.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
AS OF 12Z...VFR EXPECTED THROUGH THIS TAF VALID PERIOD. KLTX
VAD WIND PROFILE INDICATES N WINDS JUST OFF THE SURFACE SO THE
COLD FRONT SOUTH OF KMYR WITHIN HE NEXT HOUR OR TWO. IT ALSO
INDICATES A SMATTERING MID CLOUD LAYERS WITH A MORE PERSISTENT
CLOUD DECK 18K-20K.
WINDS WILL BE N-NE THIS MORNING BECOMING E AT THE COASTAL
TERMINALS IN THE AFTERNOON. MID/UPPER CLOUDS WILL MOVE OFF IN THE
AFTERNOON AS A FEW/SCT LOW LEVEL CU DEVELOPS. UPPER CLOUDS RETURN
IN THE LATE EVENING AS WINDS BECOME NE FOR THE OVERNIGHT PERIOD.
NO FOG EXPECTED.
EXTENDED OUTLOOK...VFR. ISOLATED SHOWERS FRIDAY...BECOMING SCATTERED
SAT AND SUN. BETTER CHANCES FOR CONVECTION MON.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 645 AM WEDNESDAY...THE COLD FRONT EXTENDS FROM JACKSONVILLE
NC...TO WHITEVILLE TO SOUTH OF FLORENCE SC...AND SHOULD FINALLY MAKE
ITS WAY OFF THE BEACHES A COUPLE HOURS AFTER SUNRISE...SHIFTING WEST
WINDS TO THE NORTH. IT STILL APPEARS THERE WILL BE LITTLE NORTHERLY
SURGE BEHIND THE FRONT: UPSTREAM OBSERVATIONS SHOW LITTLE INCREASE
IN WIND SPEED...SUPPORTING THE 00Z NAM SOLUTION OVER THE 00Z GFS. IN
FACT THE 00Z GFS APPEARS TO HAVE HAD PROBLEMS THIS MORNING WITH A
TOO-RAPID FRONTAL PASSAGE AND ODD WIND DIRECTIONS THROUGHOUT THE DAY
COMPARED TO THE REST OF THE MODELS. FOR WINDS I HAVE STAYED CLOSER
THE 00Z NAM AS A RESULT.
ONCE THE FRONT MOVES THROUGH NORTH WINDS ARE EXPECTED THIS
MORNING...VEERING NE THIS AFTERNOON. A WEAK SEABREEZE MAY TURN
NEARSHORE DIRECTIONS EASTERLY. HIGH PRESSURE WILL BUILD EAST ACROSS
THE GREAT LAKES TONIGHT WITH OUR WINDS TURNING MORE EASTERLY WITH
TIME.
SEAS CURRENTLY 3-4 FEET AWAY FROM THE COAST WILL FALL TO 2-3 FT THIS
AFTERNOON...BUT MAY BUILD AGAIN LATE TONIGHT AS EAST-NORTHEAST WINDS
INCREASE IN SPEED.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM WEDNESDAY...HIGH PRESSURE BUILDING DOWN FROM THE
NORTH WILL SHIFT EAST THROUGH THE PERIOD EVENTUALLY SHIFTING OFF
THE MID ATLANTIC COAST ON FRI. NORTHEASTERLY FLOW UP TO 15 KTS ON
THE FRONT END WILL LIGHTEN AND VEER AROUND BECOMING MORE NORTHEAST
TO EAST THROUGH THURS AND THEN E-SE FRI NIGHT INTO THE WEEKEND.
SEAS WILL BASICALLY REMAIN IN THE 2 TO 4 FT RANGE.
.LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 300 AM WEDNESDAY...HIGH PRESSURE WILL SHIFT OFFSHORE EARLY
IN THE WEEKEND PRODUCING A SOUTHEASTERLY ON SHORE FLOW LESS THAN
15 KTS. A SEA BREEZE WILL DEVELOP EACH AFTERNOON ADDING TO THE SE
PUSH AND PRODUCING GUSTY ON SHORE WINDS AND SOME CHOP IN THE NEAR
SHORE WATERS EACH AFTERNOON. OVERALL EXPECT SEAS IN THE 2 TO 4 FT
RANGE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...TRA
SHORT TERM...RGZ
LONG TERM...RGZ
AVIATION...MRR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
648 AM EDT WED MAY 13 2015
.SYNOPSIS...
LESS HUMID AIR WILL ARRIVE TODAY AND SHOULD LAST INTO EARLY FRIDAY AS
HIGH PRESSURE BUILDS DOWN FROM THE NORTH. THE LATTER PART OF THE
WEEK AND WEEKEND WILL FEATURE A GRADUAL INCREASE IN HUMIDITY AND
THUNDERSTORM CHANCES AS THE HIGH MOVES OFF THE COAST.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 645 AM WEDNESDAY...THE COLD FRONT RUNS FROM NEAR JACKSONVILLE
NC TO NEAR WHITEVILLE TO SOUTH OF FLORENCE SC. THIS IS STILL SLOWER
THAN ANY MODEL SHOWED JUST FIVE HOURS AGO...BUT IT APPEARS THE
LATEST HRRR MODEL HAS A REASONABLE HANDLE ON THE MOVEMENT OF THIS
FEATURE OVER THE NEXT FEW HOURS. THE 00Z GFS APPEARS TO HAVE HAD
PROBLEMS THIS MORNING WITH A TOO-RAPID FRONTAL PASSAGE AND ODD WIND
DIRECTIONS THROUGHOUT THE DAY COMPARED TO THE REST OF THE MODELS.
FOR WINDS AND TEMPERATURES I HAVE STAYED CLOSER THE 00Z NAM AS A
RESULT.
SHOWER CHANCES ARE QUITE LOW THROUGH THE MORNING. FORECAST SOUNDINGS
SHOW A SMALL REGION OF CONDITIONAL INSTABILITY BASED ABOVE THE
SURFACE WHICH COULD GENERATE AN ISOLATED SHOWER UP THROUGH THE TIME
OF FRONTAL PASSAGE. HOWEVER GIVEN POOR FORCING AND INCREASING
LIMITED VERTICAL MOISTURE...ODDS OF DEVELOPING SHOWERS ARE LESS THAN
10 PERCENT...AND WILL NOT BE MENTIONED IN THE FORECAST.
CONSIDERABLE CIRRUS CLOUDINESS WILL HANG AROUND THROUGH THE MORNING.
GLANCING OUT IN THE NWS OFFICE PARKING LOT THE CLOUDS ARE FAIRLY
OPAQUE BUT HAVE ENOUGH BREAKS AND THIN SPOTS TO LET ENOUGH SUN
THROUGH TO BOOST TEMPERATURES INTO THE UPPER 70S BY NOON. NEARLY
FULL SUNSHINE SHOULD DEVELOP THIS AFTERNOON AS THE CIRRUS ADVECTS
OFFSHORE...AND HIGHS SHOULD REACH 79-84 AWAY FROM THE BEACHES.
LINEAR MOTION EXTRAPOLATION ON THE BACK EDGE OF THE CLOUDS BRINGS IT
TO FLORENCE AROUND NOON...AND WILMINGTON AROUND 2 PM.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM WEDNESDAY...HIGH PRESSURE WILL SETTLE DOWN OVER THE
CAROLINAS FROM THE NORTH AS MID TO UPPER RIDGE ALIGNS ITSELF UP
THE EAST COAST THURS INTO FRI. OVERALL EXPECT A RAIN FREE PERIOD
WITH PLENTY OF DRY AIR AND SUBSIDENCE THROUGH THE MID LEVELS OF
THE ATMOSPHERE. MAY SEE SOME FLAT CU DEVELOPING WITH HEATING OF
THE DAY AIDED BY SOME CONVERGENCE ALONG SEA BREEZE BUT STRONG
SUBSIDENCE INVERSION WILL NOT ALLOW MUCH DEPTH TO ANY CU. ALTHOUGH
SUNSHINE SHOULD BE QUITE PLENTIFUL THROUGH THE PERIOD...SOME
HIGHER LEVEL CLOUDS WILL SPREAD INTO THE CAROLINAS OVER THE RIDGE
AS IT SLIPS EAST...ESPECIALLY TOWARD THE END OF THE FRIDAY. THE
CENTER OF THE SFC HIGH WILL SHIFT FURTHER EAST ALSO...OFF THE MID
ATLANTIC COAST BY LATE FRI. THEREFORE DRIER NORTHERLY FLOW WILL
SHIFT TO A GREATER ON SHORE TO S-SE MOISTER RETURN FLOW THROUGH
FRI NIGHT INTO THE WEEKEND AND AIR MASS WILL BEGIN TO MODIFY.
AN OVERALL DRY AIR MASS IN PLACE WILL PRODUCE GREAT DIURNAL
SWINGS WITH LOWER DEWPOINTS DOWN CLOSE TO 50 ALLOWING OVERNIGHT
TEMPS TO DROP OFF QUICKLY DOWN TO THE 50S UNDER MAINLY CLEAR SKIES
AND LIGHT TO CALM WINDS. AFTER A RELATIVELY COOLER START TO THE
DAYS...TEMPS WILL RECOVER TO NEAR SEASONABLE VALUES UNDER MAY
SUNSHINE...INTO THE UPPER 70S MOST PLACES.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 300 AM WEDNESDAY...MID TO UPPER RIDGE WILL SHIFT A LITTLE
BUT OVERALL WILL CONTINUE TO HOLD ON UP THROUGH THE
SOUTHEAST...PRODUCING SUBSIDENCE OVER THE AREA. THE SFC HIGH WILL
CONTINUE TO SLIP FARTHER EAST WHICH WILL PRODUCE A GREATER
SOUTHERLY RETURN FLOW OF MOISTURE WITH DEWPOINT TEMPS REACHING
BACK UP INTO AND THROUGH THE 60S DURING THE WEEKEND INTO EARLY
NEXT WEEK. SOME MID TO HIGH CLOUDS WILL CONTINUE TO RIDE OVER THE
RIDGE INTO THE AREA BUT OVERALL EXPECT A GOOD DEAL OF SUNSHINE
WITH AFTN TEMPS REACHING CLOSER TO SEASONABLE VALUES THROUGH THE
WEEKEND AND THEN ABOVE NORMAL AS HIGHER DEWPOINTS KEEP OVERNIGHT
LOWS IN THE 60S SAT NIGHT ONWARD. TEMPS DURING THE DAY WILL REACH
UP INTO THE 80S AS H5 HEIGHTS AND 850 TEMPS REMAIN ON RISING TREND
THROUGH EARLY NEXT WEEK. SUBSIDENCE ALOFT SHOULD ONLY ALLOW FOR
LOCALIZED CONVECTION TO DEVELOP MAINLY ASSOCIATED WITH THE SEA
BREEZE THROUGH MONDAY. BY TUES...THE RIDGE FLATTENS AND COLD FRONT
APPROACHES THE AREA WITH THE BEST CHC OF PCP COMING MID WEEK NEXT
WEEK.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
AS OF 06Z...THE COLD FRONT SHOULD MOVE OFF THE COAST AROUND 10Z. AN
ISOLATED SHOWER CAN NOT BE RULED OUT...BUT IT IS A REMOTE
POSSIBILITY. POST FRONTAL...LOOK FOR NORTHERLY WINDS AROUND 10 KTS
WITH A MID CLOUD CEILING WORST CASE. AFTER DAYBREAK...VFR CONTINUES.
WINDS WILL VEER TO THE NORTHEAST BY MID MORNING...BECOMING EASTERLY
ALONG THE COAST IN THE AFTERNOON.
EXTENDED OUTLOOK...VFR. ISOLATED SHOWERS FRIDAY...BECOMING SCATTERED
SAT AND SUN. BETTER CHANCES FOR CONVECTION MON.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 645 AM WEDNESDAY...THE COLD FRONT EXTENDS FROM JACKSONVILLE
NC...TO WHITEVILLE TO SOUTH OF FLORENCE SC...AND SHOULD FINALLY MAKE
ITS WAY OFF THE BEACHES A COUPLE HOURS AFTER SUNRISE...SHIFTING WEST
WINDS TO THE NORTH. IT STILL APPEARS THERE WILL BE LITTLE NORTHERLY
SURGE BEHIND THE FRONT: UPSTREAM OBSERVATIONS SHOW LITTLE INCREASE
IN WIND SPEED...SUPPORTING THE 00Z NAM SOLUTION OVER THE 00Z GFS. IN
FACT THE 00Z GFS APPEARS TO HAVE HAD PROBLEMS THIS MORNING WITH A
TOO-RAPID FRONTAL PASSAGE AND ODD WIND DIRECTIONS THROUGHOUT THE DAY
COMPARED TO THE REST OF THE MODELS. FOR WINDS I HAVE STAYED CLOSER
THE 00Z NAM AS A RESULT.
ONCE THE FRONT MOVES THROUGH NORTH WINDS ARE EXPECTED THIS
MORNING...VEERING NE THIS AFTERNOON. A WEAK SEABREEZE MAY TURN
NEARSHORE DIRECTIONS EASTERLY. HIGH PRESSURE WILL BUILD EAST ACROSS
THE GREAT LAKES TONIGHT WITH OUR WINDS TURNING MORE EASTERLY WITH
TIME.
SEAS CURRENTLY 3-4 FEET AWAY FROM THE COAST WILL FALL TO 2-3 FT THIS
AFTERNOON...BUT MAY BUILD AGAIN LATE TONIGHT AS EAST-NORTHEAST WINDS
INCREASE IN SPEED.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM WEDNESDAY...HIGH PRESSURE BUILDING DOWN FROM THE
NORTH WILL SHIFT EAST THROUGH THE PERIOD EVENTUALLY SHIFTING OFF
THE MID ATLANTIC COAST ON FRI. NORTHEASTERLY FLOW UP TO 15 KTS ON
THE FRONT END WILL LIGHTEN AND VEER AROUND BECOMING MORE NORTHEAST
TO EAST THROUGH THURS AND THEN E-SE FRI NIGHT INTO THE WEEKEND.
SEAS WILL BASICALLY REMAIN IN THE 2 TO 4 FT RANGE.
.LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 300 AM WEDNESDAY...HIGH PRESSURE WILL SHIFT OFFSHORE EARLY
IN THE WEEKEND PRODUCING A SOUTHEASTERLY ON SHORE FLOW LESS THAN
15 KTS. A SEA BREEZE WILL DEVELOP EACH AFTERNOON ADDING TO THE SE
PUSH AND PRODUCING GUSTY ON SHORE WINDS AND SOME CHOP IN THE NEAR
SHORE WATERS EACH AFTERNOON. OVERALL EXPECT SEAS IN THE 2 TO 4 FT
RANGE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...TRA
SHORT TERM...RGZ
LONG TERM...RGZ
AVIATION...TRA/DL
AREA FORECAST DISCUSSION
NWS PENDLETON OR
758 AM PDT WED MAY 13 2015
.UPDATE...THE LATEST RADAR WAS SHOWING A BLOB OF LIGHT TO MODERATE
RAIN OVER THE COLUMBIA BASIN AND HAVE INCREASED POPS OVER THIS
AREA THIS MORNING. MEANWHILE WEB CAMS WERE STILL SHOWING -SN ABOVE
4K IN THE BLUE MOUNTAINS AND ADJUSTED SNOW LEVELS SOME TO INDICATE
THIS. THE PCPN WAS A RESULT OF A STUBBORN LOW PRESSURE SYSTEM OVER
THE TWO STATE AREA WHICH WILL REMAIN STATIONARY OVER WA/OR AND THE
PCPN IS EXPECTED TO CONTINUE MAINLY NORTH OF THE STATE LINE TODAY.
HOWEVER RAP AROUND MOISTURE WILL PERSIST INTO MOSTLY NORTHERN
OREGON TODAY AND THE PRESENT SHORT TERM FORECAST APPEARS ON TRACK
FOR NOW.
&&
.PREV DISCUSSION... /ISSUED 300 AM PDT WED MAY 13 2015/
SHORT TERM...TODAY THROUGH THURSDAY NIGHT...AN UPPER LOW CONTINUES
TO ROTATE NORTHEAST ACROSS EASTERN OREGON EARLY THIS MORNING. THERE
IS AN AREA OF HEAVY PRECIP LOCATED TO THE NORTH AND NORTHWEST OF
THIS LOW. THUS HEAVY PRECIP HAS BEEN FALLING FROM NORTHERN GRANT
COUNTY INTO THE BLUE MOUNTAINS, GRANDE RONDE VALLEY, THE BLUE
MOUNTAIN FOOTHILLS, AND LOWER COLUMBIA BASIN EARLY THIS MORNING.
PRECIP AMOUNTS IN THE BLUES AND BLUE MTN FOOTHILLS HAVE BEEN
SUFFICIENT TO PROMPT THE ISSUANCE OF SMALL STREAM FLOOD ADVISORY FOR
THESE AREAS. ALSO SNOW LEVELS HAVE LOWERED IN THE BLUES TO NEAR 4500
FEET, LOCALLY TO 4000 FEET IN THE HEAVIEST PRECIP AREAS. COULD SEE 4
TO 8 INCHES OF SNOW ABOVE 4500 FEET AND HAVE ISSUED A WINTER STORM
WARNING FOR THE NORTHERN OREGON BLUE MOUNTAINS ZONE. THIS MAIN AREA
OF HEAVY PRECIP WILL GRADUALLY LIFT OFF TO THE NORTHWEST THIS
MORNING. THUS WILL KEEP POPS HIGH ACROSS OUR WASHINGTON ZONES
THROUGH THE MORNING. SHOULD SEE A GRADUAL END TO THE PRECIP ACROSS
NORTHEAST OREGON. CENTRAL OREGON WILL BE MOSTLY DRY THIS MORNING.
THE STEADY PRECIP WILL PERSIST OVER KITTITAS COUNTY AND PORTIONS OF
YAKIMA COUNTY INTO THE AFTERNOON. INSTABILITY LOOKS TO RATHER
LIMITED ACROSS OUR OREGON ZONES THIS AFTERNOON, BUT WILL CONTINUE TO
INDICATE ISOLATED TO SCATTERED SHOWERS. ALSO WILL LEAVE A SLIGHT
CHANCE MENTION OF THUNDERSTORMS FROM CENTRAL OREGON EAST TO GRANT
COUNTY AND NORTHEAST TO THE BLUE MOUNTAINS, GRANDE RONDE VALLEY AND
WALLOWA COUNTY. SHOWERS WILL DECREASE ACROSS MUCH OF THE AREA LATE
THIS EVENING AND OVERNIGHT, THOUGH ANOTHER WAVE ROTATING INTO THE
REGION LOOKS TO POTENTIALLY INCREASE SHOWER CHANCES OVER CENTRAL
OREGON LATE TONIGHT INTO THURSDAY MORNING. THIS SAME WAVE WILL
DESTABILIZE THE AIR MASS OVER THE REGION THURSDAY AFTERNOON AND
EVENING WITH VARYING CHANCES OF SHOWERS EXPECTED FOR MOST AREAS.
ALSO A FEW THUNDERSTORMS WILL BE POSSIBLE FOR MANY LOCATIONS. 90
LONG TERM...FRIDAY THROUGH WEDNESDAY...PATTERN WILL BE DOMINATED BY
GENERAL UPPER LEVEL TROUGHINESS THROUGH THE PERIOD. THERE WILL NOT
BE A MAJOR STORM SYSTEM...BUT IT APPEARS THAT THERE WILL BE
UNSETTLED WEATHER THROUGH THE MIDDLE OF NEXT WEEK. THE ATMOSPHERE
WILL BE MARGINALLY UNSTABLE EACH AFTERNOON...AND WITH SUFFICIENT
MOISTURE...SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL
DEVELOP. RIGHT NOW IT APPEARS THAT THE WETTEST DAYS COULD BE MONDAY
AND TUESDAY OF NEXT WEEK BUT THAT WILL CERTAINLY BE SUBJECT TO
CHANGE GIVEN THE WEAK UPPER LEVEL FORCING. THAT BEING SAID...DURING
THE NEXT SEVERAL DAYS SOME AREAS COULD SEE BENEFICIAL RAIN.
TEMPERATURES WILL BE DEPENDENT ON CLOUD COVER BUT SHOULD BE NEAR
NORMAL FOR THIS TIME OF YEAR. 78
AVIATION...12Z TAFS...MOSTLY VFR CONDITIONS ARE EXPECTED THROUGH
THE FORECAST PERIOD. AN AREA OF MODERATE RAIN OVER THE BLUE MOUNTAIN
FOOTHILLS WILL ROTATE WWD TOWARD KYKM THROUGH THE DAY WITH
ASSOCIATED MVFR CIGS AND VSBYS. OTHERWISE EXPECT BKN-OVC CONDITIONS
AT AROUND 5000 FEET AGL. WINDS WILL BE WESTERLY AT 10-20 KT AND
GUSTY DIMINISHING TONIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 62 43 67 47 / 90 10 30 30
ALW 63 47 69 51 / 90 10 30 30
PSC 64 46 73 51 / 100 10 20 20
YKM 58 45 70 49 / 90 30 20 20
HRI 66 43 72 51 / 90 10 30 20
ELN 57 42 70 48 / 90 40 20 20
RDM 63 39 61 42 / 20 30 50 40
LGD 60 40 64 47 / 80 20 30 30
GCD 63 38 64 43 / 30 20 50 40
DLS 65 47 71 51 / 40 20 30 30
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...WINTER STORM WARNING UNTIL 11 AM PDT THIS MORNING FOR ORZ502.
WA...NONE.
&&
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
97/99/99
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
1013 AM CDT WED MAY 13 2015
.DISCUSSION...TORNADO WATCH HAS BEEN ISSUED FOR PORTIONS OF OUR
AREA. UPDATED FORECAST FOR THIS...AND ADJUSTED SOME SHORT-TERM
PARAMETERS AS WELL. HAVE NOT LOOKED AT TOO MUCH IN NEW MODEL DATA
AND FORECAST TRENDS...SO DID NOT CHANGE ANYTHING AFTER TODAY.
LOOKS THOUGH THAT THINGS WILL QUIET DOWN A BIT AFTER TODAY...BUT
STILL ENOUGH MOISTURE FOR CONVECTION THROUGH MOST OF THE FORECAST.
NO REAL CHANGES TO THE MARINE. PRODUCTS ARE OUT.
&&
.PREV DISCUSSION... /ISSUED 649 AM CDT WED MAY 13 2015/
DISCUSSION...UPDATED FOR 12Z AVIATION.
AVIATION...CONVECTION WILL BE THE MAIN AVIATION CONCERN IN THE
IMMEDIATE TERM AT CRP TERMINAL...AND HAVE INCLUDED TSRA REMARKS.
ADDITIONAL SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE AS THE DAY
PROGRESSES AND HAVE VCTS/TEMPO TSRA AT ALL TERMINALS. IF
THUNDERSTORMS DIRECTLY IMPACT THE TERMINALS THEN REDUCED VSBYS AND
ERRATIC WINDS WILL BE POSSIBLE. OUTSIDE OF THUNDERSTORMS WINDS
WILL GENERALLY BE OUT OF THE EAST AND SOUTHEAST.
PREV DISCUSSION... /ISSUED 440 AM CDT WED MAY 13 2015/
SHORT TERM (TODAY THROUGH THURSDAY)...THE FORECAST IS NOT EASY.
AS OF WRITING...A THIN AXIS CONTAINING DEEPEST MOISTURE WAS
LOCATED ALONG AND JUST OFFSHORE OF THE MIDDLE TEXAS COAST.
MODEST...BUT GRADUALLY STRENGTHENING...LOW LEVEL MOISTURE
ADVECTION WAS OCCURRING INTO THE AREA OF DEEPER MOISTURE.
THIS...IN ADDITION TO AN APPROACHING H5 VORT MAX...HAS LED TO
SIGNIFICANT SHOWERS AND THUNDERSTORMS PERSISTING OVER THE PAST
SEVERAL HOURS ACROSS THE NEARSHORE WATERS. AFTER COLLABORATION
WITH THE SATELLITE PRECIPITATION ANALYSIS BRANCH ABOUT WHERE HEAVY
RAINFALL POTENTIAL MAY OCCUR...HAVE DECIDED TO EXPAND FLASH FLOOD
WATCH INTO THE NORTHERN COASTAL BEND TO ACCOUNT FOR POTENTIAL OF
DEEPER MOISTURE AXIS SHIFTING NORTHWARD...WHICH COULD LEAD TO
HOURLY RAINFALL RATES OF 1 TO 3 INCHES. ELSEWHERE
INLAND...ISOLATED TO SCATTERED CONVECTION IS GRADUALLY DEVELOPING
IN RESPONSE TO A STRENGTHENING ESE 925MB LLJ. RAP MID LEVEL
HEIGHT ANALYSIS OVERLAID WITH WATER VAPOR IMAGERY INDICATES AN
APPROACHING MID LEVEL S/W TROUGH WHICH SHOULD AID IN CONVECTIVE
DEVELOPMENT ALONG THE RIO GRANDE BY SUNRISE. THE OVERALL FORECAST
FOR TODAY CALLS FOR CONVECTION ALONG THE COAST TO PERSIST AND
BUILD NORTHWARD THROUGH MID MORNING WITH ADDITIONAL CONVECTION
DEVELOPING/EXPANDING IN AREAL COVERAGE ALONG THE RIO GRANDE AND
BEGIN TO SHIFT NE. LOCALLY HEAVY RAINFALL WILL BE POSSIBLE PRETTY
MUCH ANYWHERE TODAY AS PWATS REMAIN HIGH. A STRONG STORM WILL BE
POSSIBLE ACROSS THE REGION GIVEN EXPECTED MLCAPE VALUES AROUND
2000 J/KG AND SUFFICIENT BULK SHEAR VALUES /ESPECIALLY ACROSS NW
COUNTIES/. MAIN MID LEVEL TROUGH AXIS SWINGS THROUGH THE AREA BY
LATE TODAY RESULTING IN DRIER CONDITIONS TONIGHT. CAVEAT IS THAT A
A MINOR S/W TROUGH MAY PUSH ACROSS TONIGHT WHICH MAY LEAD TO
ADDITIONAL CONVECTIVE CHANCES...ESPECIALLY ACROSS SOUTHERN ZONES.
GUIDANCE INDICATES SOME DRIER AIR AT H85 BUILDING INTO THE REGION
ON THURSDAY RESULTING IN LOWER PRECIP CHANCES.
WILL ALLOW RIP CURRENT RISK TO EXPIRE AT 6 AM. A MODERATE RISK OF
RIP CURRENTS WILL EXIST TODAY AND MAY FLIRT WITH THE HIGH RISK
THRESHOLD AGAIN ON THURSDAY.
LONG TERM (THURSDAY NIGHT THROUGH TUESDAY)...AN UPPER LEVEL
DISTURBANCE WILL MOVE OUT OF MEXICO THURSDAY NIGHT INTO FRIDAY.
THIS WILL LEAD TO CONTINUED CHANCES OF SHOWERS AND STORMS OVER THE
WEST THURSDAY NIGHT...SHIFTING TO THE NORTHERN SECTIONS ON FRIDAY.
RAIN CHANCES MAY TEMPORARILY LOWER ON SATURDAY THE SHORTWAVE
TROUGH PASSES OFF TO THE NORTHEAST. WILL KEEP SOME LOW END 20 POPS
THOUGH WITH LINGERING MOISTURE ACROSS SOUTH TEXAS. ACTIVE WEATHER
PATTERN APPEARS TO RETURN BEGINNING SUNDAY THROUGH THE FIRST PART
OF NEXT WEEK. SOUTHWEST FLOW ALOFT WITH OCCASIONAL UPPER
DISTURBANCES WILL TRAVERSE THE REGION DURING THIS TIME. SUPERBLEND
POPS GENERALLY RANGE FROM 30 TO 50 PERCENT...AND WILL KEEP
OFFICIAL FORECAST SIMILAR TO SUPERBLEND NUMBERS. TEMPERATURES IN
THE 80S WILL BE COMMON THROUGH THE PERIOD...WITH LOWER 90S OVER
THE WESTERN ZONES FRIDAY THROUGH SUNDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 83 74 86 75 84 / 60 30 30 20 30
VICTORIA 81 72 88 73 83 / 70 40 30 20 40
LAREDO 85 72 91 73 90 / 60 20 20 30 30
ALICE 85 72 89 73 86 / 60 20 30 20 30
ROCKPORT 83 76 85 76 80 / 60 30 20 20 30
COTULLA 82 70 89 71 87 / 70 20 20 40 30
KINGSVILLE 86 74 88 75 86 / 60 30 30 20 30
NAVY CORPUS 83 75 84 76 81 / 60 30 20 20 30
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...FLASH FLOOD WATCH UNTIL 3 PM CDT THIS AFTERNOON FOR THE
FOLLOWING ZONES: ARANSAS...BEE...CALHOUN...DUVAL...GOLIAD...
JIM WELLS...KLEBERG...LA SALLE...LIVE OAK...MCMULLEN...
NUECES...REFUGIO...SAN PATRICIO...VICTORIA...WEBB.
GM...NONE.
&&
$$
GW/86...SHORT TERM
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
649 AM CDT WED MAY 13 2015
.DISCUSSION...UPDATED FOR 12Z AVIATION.
&&
.AVIATION...CONVECTION WILL BE THE MAIN AVIATION CONCERN IN THE
IMMEDIATE TERM AT CRP TERMINAL...AND HAVE INCLUDED TSRA REMARKS.
ADDITIONAL SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE AS THE DAY
PROGRESSES AND HAVE VCTS/TEMPO TSRA AT ALL TERMINALS. IF
THUNDERSTORMS DIRECTLY IMPACT THE TERMINALS THEN REDUCED VSBYS AND
ERRATIC WINDS WILL BE POSSIBLE. OUTSIDE OF THUNDERSTORMS WINDS
WILL GENERALLY BE OUT OF THE EAST AND SOUTHEAST.
&&
.PREV DISCUSSION... /ISSUED 440 AM CDT WED MAY 13 2015/
SHORT TERM (TODAY THROUGH THURSDAY)...THE FORECAST IS NOT EASY.
AS OF WRITING...A THIN AXIS CONTAINING DEEPEST MOISTURE WAS
LOCATED ALONG AND JUST OFFSHORE OF THE MIDDLE TEXAS COAST.
MODEST...BUT GRADUALLY STRENGTHENING...LOW LEVEL MOISTURE
ADVECTION WAS OCCURRING INTO THE AREA OF DEEPER MOISTURE.
THIS...IN ADDITION TO AN APPROACHING H5 VORT MAX...HAS LED TO
SIGNIFICANT SHOWERS AND THUNDERSTORMS PERSISTING OVER THE PAST
SEVERAL HOURS ACROSS THE NEARSHORE WATERS. AFTER COLLABORATION
WITH THE SATELLITE PRECIPITATION ANALYSIS BRANCH ABOUT WHERE HEAVY
RAINFALL POTENTIAL MAY OCCUR...HAVE DECIDED TO EXPAND FLASH FLOOD
WATCH INTO THE NORTHERN COASTAL BEND TO ACCOUNT FOR POTENTIAL OF
DEEPER MOISTURE AXIS SHIFTING NORTHWARD...WHICH COULD LEAD TO
HOURLY RAINFALL RATES OF 1 TO 3 INCHES. ELSEWHERE
INLAND...ISOLATED TO SCATTERED CONVECTION IS GRADUALLY DEVELOPING
IN RESPONSE TO A STRENGTHENING ESE 925MB LLJ. RAP MID LEVEL
HEIGHT ANALYSIS OVERLAID WITH WATER VAPOR IMAGERY INDICATES AN
APPROACHING MID LEVEL S/W TROUGH WHICH SHOULD AID IN CONVECTIVE
DEVELOPMENT ALONG THE RIO GRANDE BY SUNRISE. THE OVERALL FORECAST
FOR TODAY CALLS FOR CONVECTION ALONG THE COAST TO PERSIST AND
BUILD NORTHWARD THROUGH MID MORNING WITH ADDITIONAL CONVECTION
DEVELOPING/EXPANDING IN AREAL COVERAGE ALONG THE RIO GRANDE AND
BEGIN TO SHIFT NE. LOCALLY HEAVY RAINFALL WILL BE POSSIBLE PRETTY
MUCH ANYWHERE TODAY AS PWATS REMAIN HIGH. A STRONG STORM WILL BE
POSSIBLE ACROSS THE REGION GIVEN EXPECTED MLCAPE VALUES AROUND
2000 J/KG AND SUFFICIENT BULK SHEAR VALUES /ESPECIALLY ACROSS NW
COUNTIES/. MAIN MID LEVEL TROUGH AXIS SWINGS THROUGH THE AREA BY
LATE TODAY RESULTING IN DRIER CONDITIONS TONIGHT. CAVEAT IS THAT A
A MINOR S/W TROUGH MAY PUSH ACROSS TONIGHT WHICH MAY LEAD TO
ADDITIONAL CONVECTIVE CHANCES...ESPECIALLY ACROSS SOUTHERN ZONES.
GUIDANCE INDICATES SOME DRIER AIR AT H85 BUILDING INTO THE REGION
ON THURSDAY RESULTING IN LOWER PRECIP CHANCES.
WILL ALLOW RIP CURRENT RISK TO EXPIRE AT 6 AM. A MODERATE RISK OF
RIP CURRENTS WILL EXIST TODAY AND MAY FLIRT WITH THE HIGH RISK
THRESHOLD AGAIN ON THURSDAY.
LONG TERM (THURSDAY NIGHT THROUGH TUESDAY)...AN UPPER LEVEL
DISTURBANCE WILL MOVE OUT OF MEXICO THURSDAY NIGHT INTO FRIDAY.
THIS WILL LEAD TO CONTINUED CHANCES OF SHOWERS AND STORMS OVER THE
WEST THURSDAY NIGHT...SHIFTING TO THE NORTHERN SECTIONS ON FRIDAY.
RAIN CHANCES MAY TEMPORARILY LOWER ON SATURDAY THE SHORTWAVE
TROUGH PASSES OFF TO THE NORTHEAST. WILL KEEP SOME LOW END 20 POPS
THOUGH WITH LINGERING MOISTURE ACROSS SOUTH TEXAS. ACTIVE WEATHER
PATTERN APPEARS TO RETURN BEGINNING SUNDAY THROUGH THE FIRST PART
OF NEXT WEEK. SOUTHWEST FLOW ALOFT WITH OCCASIONAL UPPER
DISTURBANCES WILL TRAVERSE THE REGION DURING THIS TIME. SUPERBLEND
POPS GENERALLY RANGE FROM 30 TO 50 PERCENT...AND WILL KEEP
OFFICIAL FORECAST SIMILAR TO SUPERBLEND NUMBERS. TEMPERATURES IN
THE 80S WILL BE COMMON THROUGH THE PERIOD...WITH LOWER 90S OVER
THE WESTERN ZONES FRIDAY THROUGH SUNDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 83 74 86 75 84 / 60 30 30 20 30
VICTORIA 81 72 88 73 83 / 60 40 30 20 40
LAREDO 85 72 91 73 90 / 60 20 20 30 30
ALICE 85 72 89 73 86 / 50 20 30 20 30
ROCKPORT 83 76 85 76 80 / 60 30 20 20 30
COTULLA 82 70 89 71 87 / 70 20 20 40 30
KINGSVILLE 86 74 88 75 86 / 60 30 30 20 30
NAVY CORPUS 83 75 84 76 81 / 60 30 20 20 30
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...FLASH FLOOD WATCH UNTIL 3 PM CDT THIS AFTERNOON FOR THE
FOLLOWING ZONES: ARANSAS...BEE...CALHOUN...DUVAL...GOLIAD...
JIM WELLS...KLEBERG...LA SALLE...LIVE OAK...MCMULLEN...
NUECES...REFUGIO...SAN PATRICIO...VICTORIA...WEBB.
GM...NONE.
&&
$$
TB/78...AVIATION
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
308 PM CDT WED MAY 13 2015
.SHORT TERM...(TONIGHT THROUGH SATURDAY)
ISSUED AT 305 PM CDT WED MAY 13 2015
TONIGHT
LATEST SHORT TERM PROGS IN AGREEMENT SHOWING THAT GOING RAINFALL
FCST FOR TONIGHT IS ON TRACK WITH PCPN ACTIVITY DEVELOPING OVER KS
THEN EXPANDING NWD INTO THE CWA EARLY THIS EVENING. GIVEN
COMBINATION OF UPPER SUPPORT VIA POTENT VORT MAX/STRONG DIVG
WORKING IN TANDEM WITH RATHER MOIST 305K UPGLIDE...SEEMS
REASONABLE TO ASSUME THAT SEVERAL LOCATIONS SHOULD SEE RAINFALL
TOTALS OF AT LEAST HALF AN INCH MAINLY OVER THE SRN CWA WHERE
LIFT/MOISTURE WILL BE MORE PREVALENT. IN ADDITION...MODELS ARE
SHOWING INSTABILITY PARAMETERS WILL BE WEAK AT BEST SO ANY TSTM
DEVELOPMENT SHOULD BE ISOLATED.
DEE
THURSDAY THROUGH SATURDAY
TIMING AND POTENTIAL FOR SEVERE STORMS BOTH FRIDAY AND SATURDAY
WILL BE THE MAIN FORECAST CONCERNS.
OUR AREA WILL GENERALLY BE IN SOUTH OR SOUTHWEST MID TROPOSPHERIC
FLOW THE NEXT FEW DAYS. WATER VAPOR IMAGERY EARLY THIS WEDNESDAY
AFTERNOON...IN COMBINATION WITH EARLY AFTERNOON RAP MODEL
INTITIALIZATIONS...SHOWED FAIRLY IMPRESSIVE SHORTWAVE TROUGH FROM
COLORADO DOWN INTO WEST TEXAS. THIS WILL LIFT NORTHEAST ACROSS THE
AREA TONIGHT AND THURSDAY. BRIEF SHORTWAVE RIDGING BUILDS IN FOR
LATE THURSDAY/EARLY THURSDAY NIGHT...WHILE A STRONG CLOSED LOW
DIGS DOWN INTO NEVADA AND CALIFORNIA. GENERAL MODEL CONSENSUS
SHOWS THE CENTER OF THAT 500 MB LOW SHOULD LIFT OUT INTO NORTHEAST
WYOMING OR SOUTHEAST MONTANA BY SATURDAY EVENING.
THURSDAY...SHOWERS WILL LINGER AT LEAST IN THE MORNING...WITH
ISOLATED THUNDER POSSIBLE. CHANCES DECREASE THROUGH THE AFTERNOON.
EXPECT AT LEAST THE SOUTHWEST HALF OF OUR FORECAST AREA TO SEE
SOME AFTERNOON SUNSHINE AND THAT SHOULD HELP PUSH HIGHS INTO THE
70S THERE. AREAS FROM AROUND YANKTON DOWN TO ONAWA...HARLAN AND
RED OAK MAY ONLY TOP OUT FROM 65 TO 70. PCPN AMOUNTS THURSDAY ARE
EXPECTED TO BE MOSTLY UNDER 0.25 INCHES.
A WEAK COLD FRONT WILL SETTLE DOWN INTO THE FORECAST AREA THURSDAY
NIGHT AND THEN STALL. SHOWERS AND THUNDERSTORMS MAY DEVELOP ALONG
AND NORTH OF THE BOUNDARY THURSDAY NIGHT AS THE LOW LEVEL JET
INCREASES AND CAUSES ISENTROPIC LIFT. BEST FOCUS SEEMS TO BE OVER
SOUTHEAST NEBRASKA.
FRIDAY AND FRIDAY NIGHT WILL BE INTERESTING. SOUTHERLY LOW LEVEL
FLOW INCREASES AS LOW PRESSURE INITIALLY OVER NORTHEAST COLORADO AT
12Z FRIDAY LIFTS NORTH TO WEST/NORTHWEST OF VALENTINE BY 06Z
SATURDAY. HIGHS FRIDAY SHOULD REACH 75 TO 80...PUSHING BOUNDARY
LAYER CAPE VALUES INTO THE 1500 TO 3000 J/KG RANGE. 0-6 KM AGL BULK
SHEAR VALUES SHOULD BE MOSTLY 25-40 KNOTS. STORMS MAY INITIALLY BE
MOSTLY NORTH OF THE FRONT...BUT THEN COULD ALSO DEVELOP IN THE WARM
SECTOR OR FARTHER BACK TO THE WEST IN CENTRAL NEBRASKA LATER IN THE
DAY. DETAILS SHOULD BECOME MORE CLEAR WITH THURSDAY MODEL RUNS ON
THE LOCATION OF FRONTAL BOUNDARIES WHICH WILL HELP FOCUS THE
ACTIVITY IN THE AFTERNOON AND EVENING. STORM COVERAGE MAY DROP OFF
DRASTICALLY AFTER MIDNIGHT.
SATURDAY...OVERALL PARAMETERS ARE EXPECTED TO BE IN PLACE FOR
ANOTHER POSSIBLE SEVERE EVENT...BUT NOT COMPLETELY SOLD ON THAT
SINCE IT WILL AT LEAST SOMEWHAT DEPEND ON WHAT HAPPENS FRIDAY. MID
LEVEL WINDS SHOULD INCREASE AND THEREFORE BULK SHEAR VALUES MAY
END UP HIGHER THAN THOSE FRIDAY. TIMING OF CONVECTION WILL BE THE
KEY.
MILLER
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 305 PM CDT WED MAY 13 2015
STORMS SHOULD LINGER INTO SATURDAY NIGHT...WITH SHOWERS/A FEW
EMBEDDED STORMS POSSIBLE SUNDAY MORNING. THE 12Z GFS WAS MOSTLY
DRY IN OUR AREA SUNDAY...BUT THE 12Z ECMWF WAS ABOUT 6 HOURS
SLOWER LIFTING PCPN OUT OF THE AREA. SO...FOR NOW WE HAVE KEPT
SOME LOW POPS SUNDAY IN OUR NORTHERN ZONES SUNDAY.
SUNDAY NIGHT THROUGH TUESDAY SHOULD BE LESS ACTIVE AS HIGH PRESSURE
BUILDS INTO THE REGION WITH COOL TEMPERATURES. SOME LOWS COULD DROP
DOWN TO NEAR 40. IT APPEARS THAT CHANCES FOR SHOWERS/STORMS WILL
INCREASE AGAIN BY TUESDAY NIGHT AND WEDNESDAY AS SHORTWAVE ENERGY
MOVES IN FROM THE WEST/SOUTHWEST.
MILLER
&&
.AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1230 PM CDT WED MAY 13 2015
A POTENT UPPER DISTURBANCE COUPLED WITH INCREASING LLVL MOISTURE
WILL TRANSLATE TO CONDITIONS DETERIORATING EARLY THIS EVENING
FROM VFR TO IFR/LIFR. EXPECT PCPN ACTIVITY TO QUICKLY EXPAND NWD
OUT OF KS AND INTO ERN NEB WITH RA PREVAILING THRU TONIGHT AND
INTO EARLY THURSDAY MORNING. INSTABILITY PARAMETERS WILL BE WEAK
AT BEST...AND ANY TSRA DEVELOPMENT WILL BE ISOLATED IN NATURE.
BECAUSE OF THIS...HAVE OPTED TO NOT INCLUDE ANY MENTION OF TS AT
THIS TIME.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...DEE/MILLER
LONG TERM...MILLER
AVIATION...DEE
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
302 PM CDT WED MAY 13 2015
.SYNOPSIS...
ISSUED AT 255 PM CDT WED MAY 13 2015
CLOSED LOW MOVING OUT OF THE GULF OF ALASKA AND MOVING INTO THE
COAST OFF THE PACIFIC NORTHWEST. RIDGE FROM THE SOUTHEAST CONUS
INTO THE NORTHERN PLAINS WITH A STRONG UPPER WAVE MOVING OUT OF
THE SOUTHERN ROCKIES ONTO THE CENTRAL PLAINS. RADAR RETURNS
DEVELOPING FROM THE TEXAS PANHANDLE INTO THE EASTERN PLAINS OF
WYOMING AND THE PANHANDLE OF NEBRASKA. WEAK TROUGH THROUGH THE
NORTHEAST CONUS.
&&
.SHORT TERM...(THIS AFTERNOON THROUGH THURSDAY)
ISSUED AT 255 PM CDT WED MAY 13 2015
MAIN FORECAST CHALLENGES INVOLVE PRECIPITATION CHANCES TONIGHT AND
INTO THURSDAY MORNING. FAIRLY SIGNIFICANT PV ANOMALY WILL CONTINUE
TO ROTATE NEWD TONIGHT WITH GOOD MOISTURE TRANSPORT AHEAD OF IT.
STRONG SRLY WINDS ADVECTING LOW TO MID 50S DEW POINTS INTO THE
REGION AS WELL. WEAK CONVERGENCE ALONG SFC TROUGH LOCATED IN THE ERN
NEB PANHANDLE STARTING TO ALLOW DEVELOPMENT OF SHRA IN WRN KEITH
COUNTY AND THIS TREND SHOULD CONTINUE AS UPPER FORCING AND
ASSOCIATED MID LEVEL FRONTOGENESIS COMBINE TO TAKE BETTER ADVANTAGE
OF WEAK INSTABILITY ACROSS PORTIONS OF WRN NEB. HOWEVER EFFECTIVE
SHEAR IS MODEST AT BEST...THEREFORE MULTICELL TYPE CONVECTION WOULD
BE EXPECTED...AND ALTHOUGH THERE IS LIMITED INSTABILITY A FEW
UPDRAFTS MAY BE SUSTAINED LONG ENOUGH TO PRODUCE SOME HAIL...THOUGH
WIDESPREAD SEVERE HAIL IS NOT EXPECTED AT THIS TIME. INCREASING
SYNOPTIC SCALE LIFT WILL ALLOW FURTHER SHRA DEVELOPMENT OVERNIGHT
ACROSS KS AND MOVING INTO SRN NEB...BUT STRONG STORMS NOT EXPECTED
GIVEN ONLY LIMITED INSTABILITY ALOFT DURING THE EVENING HOURS. WITH
CURRENT POTENTIAL FOR RIVER FLOODING WE WILL BE WATCHING QPF AMOUNTS
CAREFULLY...BUT CURRENTLY AMOUNTS GENERALLY ONE TENTH TO ONE QUARTER
INCH IS EXPECTED MOST PLACES OVERNIGHT...THOUGH ISOLATED HIGHER
AMOUNTS WILL BE POSSIBLE IN MORE ROBUST TSRA SHOULD THEY DEVELOP.
SHRA MOVES NEWD THROUGH THE LATE EVENING AND OVERNIGHT...AND SOME
POTENTIAL FOR FOG DEVELOPMENT AFTER PRECIP ENDS IN WEAKENING WINDS
TWD MORNING...ESPECIALLY IN SW NEB. CONFIDENCE ON WIDESPREAD FOG
DEVELOPMENT IS LOW SO HAVE HAVE NOT INCLUDED IN GRIDDED FCST BUT WILL
BE WATCHING TO SEE HOW PRECIP EVOLVES.
SUBSIDENCE INCREASES IN THE WAKE OF THE NEWD MOVING PV ANOMALY
DURING THE DAY THURSDAY...THOUGH LINGERING SHRA POSSIBLE IN PORTIONS
OF NORTHERN NEB. WRLY DOWSLOPE WINDS WILL TAKE OVER TO CLEAR SKIES
THROUGH THE AFTERNOON FROM WEST TO EAST AND ALSO ALLOW STRONGER
INSOLATION AND DOWNSLOPE WARMING TO OCCUR. THEREFORE HAVE SIDED WITH
WARMER GUIDANCE FOR MAX TEMPS THURSDAY...BUT TIMING OF CLOUDS
DECREASING WILL BE CRITICAL. TRANSITORY RIDGING DEVELOPS IN BETWEEN
EXITING PV ANOMALY AND MORE IMPRESSIVE PV ANOMALY TO ARRIVE EARLY
FRIDAY MORNING SO A DRYING TREND WAS FOLLOWED THROUGH THURSDAY
AFTERNOON.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 255 PM CDT WED MAY 13 2015
MID AND UPPER FEATURES FAIRLY CONSISTENT THROUGH THE MID AND LONG
TERM SOLUTIONS AND HAVE USED A BLEND FOR THE FORECAST WITH GOOD
CONFIDENCE. THURSDAY NIGHT A STATIONARY BOUNDARY WILL LIE ACROSS
THE SANDHILLS ISOLATED THUNDERSTORMS AND SHOWERS WILL DEVELOP OVER
THE NEBRASKA PANHANDLE THROUGH THE EVENING AS THE UPPER LOW TO
THE WEST MOVES EAST. AFTER MIDNIGHT STRONGER MID LEVEL ENERGY TO
MOVE ACROSS WESTERN NEBRASKA WITH THUNDERSTORMS DEVELOPING ALONG
THE BOUNDARY AND SPREADING NORTHEAST THROUGH THE SANDHILLS. FRIDAY
A SURFACE LOW OVER NORTHEAST COLORADO...IN RESPONSE TO UPPER
LOW...WILL DEEPEN THROUGH THE DAY AND A WARM FRONTAL BOUNDARY ALONG
THE KANSAS NEBRASKA BORDER WILL LIFT NORTH THROUGH THE DAY. STEEP
LAPSE RATES AND FAVORABLE HODOGRAPHS ENTIRE FORECAST AREA HAS BEEN
PLACED IN ENHANCED. WARM FRONT LIFTS SLOWLY NORTH AND INTO SOUTH
DAKOTA NEBRASKA BORDER AREA BY 12Z. WARM FRONTAL BOUNDARY WILL
REMAIN FOCUS OF SEVERE WEATHER THROUGHOUT FRIDAY. MODELS HAVE SOME
VARIANCES ON WHERE THIS BOUNDARY MIGHT LIE. HAVE CONTINUED WITH
LIKELY POPS. MOST OF WESTERN NEBRASKA DRY SLOTTED THROUGH THE DAY
ON SATURDAY. WITH GOOD WARM AIR ADVECTION TEMPERATURES RISING INTO
THE 70S BUT SURFACE LOW OVER THE DAKOTAS WILL DRAG A COOL FRONT
EAST ACROSS WESTERN NEBRASKA THROUGH THE DAY INTO THE EVENING. THE
FRONT WILL BE THE FOCUS OF THUNDERSTORM DEVELOPMENT WITH DYNAMICS
SUGGESTING ANOTHER ROUND OF SEVERE WEATHER WITH HAIL THE MAIN
THREAT. RESIDUAL SHOWERS AND TEMPERATURES FALLING INTO THE 60S ON
SUNDAY. MODELS SUGGESTING CANADIAN MODIFIED ARCTIC AIR DIVING INTO
THE NORTHERN PLAINS MONDAY WITH TEMPERATURES FALLING INTO THE 50S
AND 60S AND DRY. ANOTHER NEGATIVELY TILTED CLOSED LOW TO MOVE OUT
OF THE ROCKIES MID WEEK ONTO THE NORTHERN PLAINS WITH ANOTHER
ROUND OF PRECIP.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1250 PM CDT WED MAY 13 2015
MAIN AVIATION FCST CONCERNS REVOLVE AROUND SHRA/TSRA TIMING THIS
AFTERNOON AND EVENING. SFC TROUGH DEVELOPS IN THE PANHANDLE THIS
AFTERNOON IN RESPONSE TO UPPER PV ANOMALY MOVING NEWD IN THE NEXT
24 HRS. SOME INSTABILITY ALOFT IN CONCERT BUT CLOUD COVER WILL
LIMIT FURTHER DESTABILIZATION. HOWEVER...DECENT FGEN SIGNATURE
INDICATED IN IR SAT PICS AND LATEST 700MB RAP ANALYSIS IN NRN CO
SUGGESTS A DEEPER CIRCULATION SHOULD DEVELOP ALONG THE SFC TROUGH
LATER TO ENHANCE TSRA CHANCES THERE. FURTHER EWD...MAINLY SHRA IN
THE EVENING AND OVERNIGHT HOURS WITH LESSER INSTABILITY. DEPENDING
ON TIMING OF SHRA ENDING IN THE KLBF AND KVTN TAF SITES THERE
COULD BE BR DEVELOPMENT DURING THE EARLY MORNING HOURS. ONLY
MODERATE CONFIDENCE IN THIS HOWEVER AS WINDS SHIFT TO SWRLY DURING
MID MORNING. MORE CONFIDENCE IN THE KLBF TAF AND THEREFORE HAVE
INCLUDED FOR A LONGER PERIOD OF TIME. CLEARING SKIES TWD LATE
MORNING /END OF TAF PERIOD/ AS PRECIP MOVES OUT.
&&
.HYDROLOGY...
ISSUED AT 255 PM CDT WED MAY 13 2015
THE RIVER FORECAST WAS TRENDED SLIGHTLY LOWER TODAY FOR ROSCOE AND
BRADY...BUT LEFT AS IS NEAR THE CITY OF NORTH PLATTE. UPSTREAM
RIVER DATA FROM NORTHEASTERN COLORADO DEPICTS A BROAD CREST...WHICH
IS LOWER THAN PREVIOUSLY ANTICIPATED. DESPITE THE DOWNWARD
TREND...IT CANNOT BE STRESSED ENOUGH THAT PERSONS WHO LIVE IN
VULNERABLE AREAS ALONG THE SOUTH PLATTE RIVER IN SOUTHWEST NEBRASKA
AND PLATTE RIVER ACROSS EASTERN LINCOLN SHOULD CONTINUE TO PAY CLOSE
ATTENTION TO FLOOD FORECASTS IN THE COMING DAYS AND BE PREPARED TO
TAKE PROPER ACTION IF REQUESTED. FLOOD WARNINGS REMAIN FOR THE SOUTH
PLATTE RIVER FROM THE BORDER OF NORTHEAST COLORADO...EAST THROUGH
LINCOLN COUNTY INTO NEXT WEEK.
THE FLOODING IS A RESULT OF EARLY SNOW MELT IN THE UPPER SOUTH
PLATTE RIVER BASIN AND PREVIOUS HEAVY RAINFALL ACROSS NORTHEASTERN
COLORADO AND WESTERN NEBRASKA. UNCERTAINTY IN THE FORECAST IS
TRENDING LOWER AS THERE IS SUFFICIENT SAMPLING FROM UPSTREAM RIVER
SITES. THAT BEING SAID...MINOR FLUCTUATIONS ARE STILL
POSSIBLE...ESPECIALLY SINCE ADDITIONAL PRECIPITATION IS ANTICIPATED
ACROSS THE REGION LATE THIS AFTERNOON THROUGH THURSDAY AND AGAIN
THIS WEEKEND.
CONFIDENCE IS HIGH IN THAT THIS EVENT WILL NOT EQUAL OR EXCEED
THE RECORD FLOODING EVENT OF SEPTEMBER 2013...BUT RIVER STAGE
FORECASTS WILL CONTINUE TO BE CLOSELY MONITORED AN UPDATED AS
ADDITIONAL UPSTREAM DATA BECOME AVAILABLE.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...POWER
SHORT TERM...JWS
LONG TERM...POWER
AVIATION...JWS
HYDROLOGY...JACOBS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1251 PM CDT WED MAY 13 2015
.UPDATE...
ISSUED AT 1250 PM CDT WED MAY 13 2015
PRECIPITATIOIN CHANCES HAVE BEEN ADJUSTED SOMEWHAT FOR TIMING
BASED ON LATEST CONVECTION ALLOWING MODEL OUTPUT AND CURRENT
TRENDS ON RADAR AND SATELLITE. ECHOES INCREASING IN NERN CO AND
SRN NEB PANHANDLE IN THE LAST HOUR AS MID LEVEL FGEN INCREASING
SOMEWHAT ALONG THE SERN WY NRN CO BORDER. DEEP MOIST CONVERGENCE
INCREASING IN RESPONSE BASED ON SPC MESOANALYSIS GRAPHICS AND ECHO
MOVEMENT HAS BEE GRADUALLY TO THE NORTH...THOUGH SOME SATURATION
OF THE MIDDLE ATMOSPHERE WILL BE NEEDED TO BRING RAIN TO THE
SURFACE. OTHERWISE MAX TEMPS KEEP WHERE THEY WERE EVEN THOUGH
CLOUD COVER WILL PLAY A PART THIS AFTERNOON. WINDS WILL BE
LIGHTEST WHERE SFC TROUGH WIL FURTHER DEVELOP IN THE PANHANDLE
THIS AFTERNOON...BUT STILL QUITE GUSTY FURTHER EAST. RAIN CHANCES
FURTHER INCREASE ACROSS THE REMAINDER OF THE AREA THIS EVENING
THOUGH QPF VALUES IN GENERAL SHOULD RANGE MOSTLY BTWN ONE TENTH TO
ONE QUARTER OF AN INCH WITH LOCALIZED AMOUNTS UP TO ONE HALF INCH
POSSIBLE BY MORNING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 320 AM CDT WED MAY 13 2015
TODAY AND TONIGHT...THE SUBTROPICAL DISTURBANCE OFF OF BAJA MEXICO
YESTERDAY HAS MOVED NORTH INTO NEW MEXICO THIS MORNING. THE MODELS
LIFT THIS DISTURBANCE THROUGH THE CNTL PLAINS TODAY AND TONIGHT.
TWO CONVECTIVE ITEMS OF INTEREST HAVE BEEN IDENTIFIED AS THE
DISTURBANCE MOVES THRU WRN AND NCNTL NEBRASKA LATE THIS AFTN AND
TONIGHT. ONE IS A ROUND OF CONVECTION THAT SHOULD FIRE ON THE
COLORADO FRONT RANGE AND LARAMIE RANGE AROUND 18Z-21Z. THE STEERING
WINDS ALOFT CARRY THIS CONVECTION NNE THROUGH THE NEB PANHANDLE
AFFECTING AREAS MAINLY ALONG AND WEST OF HIGHWAY 61. MEANWHILE THE
SREF AND GEF SUGGEST A SECOND HEAVIER RAIN CENTER WILL MOVE ACROSS
WCNTL KS AND THROUGH SCNTL/ERN NEB EXITING AROUND 12Z.
THE QUESTION THOUGH IS HOW FAR WEST THE SECOND RAIN CENTER WILL
TRACK GIVEN THAT THE MODELS TREND WEST WITH RETURN MOISTURE. THE RAP
AND NAM PROVIDE AN ANSWER AS THEY ARE FARTHEST WEST AT 00Z WITH PWAT
NEAR 1.25 INCHES AND BACKED 850MB NEAR PAMPA TX. THIS MOISTURE
SHOULD MOVE NORTH-NORTHEAST DURING THE EVENING PRESENTING THE
POTENTIAL FOR HEAVY RAIN...0.5 TO 1 INCH EAST OF HIGHWAY 83 ACROSS
CUSTER COUNTY AND NORTHEAST. THE 1 INCH QPF IS SPECULATIVE. THE
MOISTURE IS VERY DEEP AND TRANSPORT EXTENDS TO 500 MB OR HIGHER AND
IS QUITE STRONG BELOW 700MB. WE WILL SEE WHAT HAPPENS TONIGHT. IF
SOME SORT OF LOW LEVEL BOUNDARY OR FOCUS DEVELOPS...NOT SHOWN BY
THE MODELS ATTM...THAN THE 1 INCH QPF COULD VERIFY SOMEWHERE. THE
QPF FORECAST FOLLOWS THE SREF AND NAM FOR UP TO 1/2 INCH OF RAIN IN
THE EAST AND UP TO 1/3 OF AN INCH WEST OF HIGHWAY 61.
THE "HURRICANE" CONTINUES TODAY. THE RAP13 500M AGL WINDS INCREASE
TO 25 TO 30 KTS WHICH IS 25 TO 30 MPH NEAR THE SFC WITH GUSTS TO 40
MPH IN OPEN AREAS.
THE TEMPERATURE FORECAST TODAY FOLLOWS THE WARM SIDE OF THE MODEL
CLUSTER FOR HIGHS IN THE LOW TO MID 70S. THE RAP SHOWS 80 NEAR
VALENTINE AND 76 AT NORTH PLATTE. MID LEVEL CLOUDINESS SHOULD INVADE
THE REGION HOLDING HIGHS DOWN BELOW THE RAP FORECAST. LOWS TONIGHT
FALL INTO THE UPPER 40S TO MID 50S. THE NAM SHOWS OVERCAST SKIES AT
09Z WITH A CLEARING LINE NEAR HIGHWAY 61 AT 12Z EARLY THURSDAY
MORNING.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 320 AM CDT WED MAY 13 2015
THE LARGE SCALE UPPER LEVEL PATTERN PERSISTS THROUGH THE END OF THE
WEEK AND INTO EARLY NEXT WEEK...DEFINED BY A DEEP TROUGH WITH
SEVERAL EMBEDDED PV ANOMALIES IN THE WESTERN CONUS AND BROAD
ANTICYCLONIC FLOW TO THE EAST. THIS PUTS THE CENTRAL CONUS IN A
FAVORABLE SYNOPTIC SETUP FOR POLEWARD MOISTURE TRANSPORT AND
RECURRING CHANCES FOR PRECIPITATION...INCLUDING THE POTENTIAL FOR
SEVERE WEATHER LATER THIS WEEK.
THURSDAY BEGINS WITH INHERITED MORNING POPS AS A SHORTWAVE DEPARTS
THE CENTRAL PLAINS AND MOVES INTO THE UPPER MS VALLEY. MODELS ARE IN
AGREEMENT WITH UPPER LEVEL HEIGHT RISES AND GRADUALLY CLEARING SKIES
BY THE AFTERNOON...SO TRENDED HIGH TEMPERATURES UP A FEW DEGREES TO
FOLLOW GUIDANCE. SFC WINDS WILL FINALLY EASE UP FOR A DAY DUE TO
WEAK PRESSURE TENANCIES OVER THE CWA...GENERALLY EXPECTING WINDS
AROUND 10 KTS.
POPS ARE QUICK TO MOVE BACK INTO THE FORECAST LATE THURSDAY AS THE
NEXT SHORTWAVE TROUGH ENTERS THE DESERT SOUTHWEST AND SWINGS OUT
TOWARD THE CENTRAL PLAINS. INCREASING DPVA ALOFT WILL PROMOTE A
DEEPENING LEE SIDE SFC TROUGH OVER EASTERN COLORADO AND THE SLOW
NORTHWARD PROGRESSION OF A WARM FRONT INTO NORTHERN KS. DEEP LAYER
MOISTURE PROFILE WILL BECOME INCREASINGLY FAVORABLE FOR
PRECIPITATION DUE TO EASTERLY UPSLOPE WINDS...AND A MID-LEVEL
SUBTROPICAL PLUME OFF THE BAJA TRANSPORTS BETTER MOISTURE ALOFT.
SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP AFTER DARK IN AN
AREA OF ISENTROPIC ASCENT NORTH OF THE WARM FRONT. THE CONVECTION
SHOULD FOLLOW THE WARM FRONT NORTHWARD INTO SOUTHERN SD EARLY
FRIDAY.
SEVERE WEATHER THREAT INCREASES FRIDAY AFTERNOON AND EVENING WITH
THE NEXT ROUND OF THUNDERSTORM ACTIVITY. SFC DEWPOINTS INCREASE TO
AROUND 60F INVOF A SHARPENING DRY LINE OVER WESTERN KS AND SOUTHWEST
NEBRASKA AND SOUTH OF THE WARM FRONT IN SOUTHERN SD. THE ATMOSPHERE
WILL BECOME QUITE UNSTABLE BY THE AFTERNOON AS MID LEVEL LAPSE RATES
STEEPEN AND SFC TEMPS WARM. THUNDERSTORMS SHOULD REFIRE ALONG THE
DRYLINE DURING THE AFTERNOON AND EVENING AS THE DRYLINE SURGES
NORTHEAST. STORMS WILL HAVE THE POTENTIAL TO BECOME SUPERCELLULAR IN
AN ENVIRONMENT CHARACTERIZED BY UP TO 2000 J/KG ML CAPE AND 40-45
KTS OF DEEP LAYER SHEAR. LARGE HAIL AND DAMAGING WIND WILL BE THE
PRIMARY THREATS...BUT LOW LEVEL SFC SHEAR PROFILES FAVOR ELONGATED
HODOGRAPHS AND THE POTENTIAL FOR A FEW TORNADOES.
THUNDERSTORMS AND THE THREAT FOR SEVERE WEATHER REDEVELOP SATURDAY
AS THE LARGE UPPER LEVEL LOW EJECTS TOWARD THE CENTRAL PLAINS. AT
THIS TIME THE AREA OF CONCERN IS GENERALLY EAST OF A SFC TROUGH
MOVING INTO CENTRAL AND EASTERN NEBRASKA. THE EARLY PART OF NEXT
WEEK LOOKS DRIER AS THE UPPER LOW KICKS NORTHEAST AND A RIDGE BUILDS
INTO THE CENTRAL CONUS. HOWEVER MODELS ARE QUICK TO BRING ANOTHER
TROUGH INTO THE ROCKIES BY TUESDAY...BRINGING WITH IT MORE CHANCES
FOR SHOWERS AND THUNDERSTORMS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1250 PM CDT WED MAY 13 2015
MAIN AVIATION FCST CONCERNS REVOLVE AROUND SHRA/TSRA TIMING THIS
AFTERNOON AND EVENING. SFC TROUGH DEVELOPS IN THE PANHANDLE THIS
AFTERNOON IN RESPONSE TO UPPER PV ANOMALY MOVING NEWD IN THE NEXT
24 HRS. SOME INSTABILITY ALOFT IN CONCERT BUT CLOUD COVER WILL
LIMIT FURTHER DESTABILIZATION. HOWEVER...DECENT FGEN SIGNATURE
INDICATED IN IR SAT PICS AND LATEST 700MB RAP ANALYSIS IN NRN CO
SUGGESTS A DEEPER CIRCULATION SHOULD DEVELOP ALONG THE SFC TROUGH
LATER TO ENHANCE TSRA CHANCES THERE. FURTHER EWD...MAINLY SHRA IN
THE EVNING AND OVERNIGHT HOURS WITH LESSER INSTABILITY. DEPENDING
ON TIMING OF SHAR ENDING IN THE KLBF AND KVTN TAF SITES THERE
COULD BE BR DEVELOPMENT DURING THE EARLY MORNING HOURS. ONLY
MODERATE CONFIDENCE IN THIS HOWEVER AS WINDS SHIFT TO SWRLY DURING
MID MORNING. MORE CONFIDENCE IN THE KLBF TAF AND THEREFORE HAVE
INCLUDED FOR A LONGER PERIOD OF TIME. CLEARING SKIES TWD LATE
MORNING /END OF TAF PERIOD/ AS PRECIP MOVES OUT.
&&
.HYDROLOGY...
ISSUED AT 1250 PM CDT WED MAY 13 2015
FLOODING STILL EXPECTED ALONG THE SOUTH PLATTE AND PLATTE RIVER
FROM THE CO STATE LINE TO ERN LINCOLN COUNTY INTO THE WEEKEND DUE
TO SNOWMELT AND HEAVY RAINS IN NERN CO A FEW DAYS AGO /SEE DETAILS
IN FLOOD PRODUCTS AND STATEMENTS/. HOWEVER...TRENDS IN THE FCST...WITH
GOOD COLLAORATION FROM MBRFC...HAS BEEN A LOWERED FCST FOR THE
CREST IN NORTH PLATTE...THOUGH GETTING TO NEAR FLOOD STAGE BY THE
WEEKEND. FURTHER DETAILS IN LATER AFTERNOON AFD.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JWS
SHORT TERM...CDC
LONG TERM...MARTIN
AVIATION...JWS
HYDROLOGY...JWS
LOCATIONS. THE PREVIOUS FORECAST DISCUSSION FOLLOWS.
KLTX VAD WIND PROFILE REGISTERING 3000 FOOT THICK NORTH FLOW
ACROSS THE REGION PRESENTLY IN WAKE OF A COLD FRONT WHICH HAS
MIGRATED SOUTH AND EAST OF THE AREA. A BAND OF MIDDLE AND HIGH
CLOUDS FROM 12 KFT UPWARD ARE TRAVERSING OUR SKIES AND WILL DO SO
THROUGH MORNING WITH AN UPTICK IN SUNSHINE MINUTES ANTICIPATED
THIS AFTERNOON. COOLING BEHIND THE FRONT WILL OCCUR MAINLY TONIGHT
AS THE GREAT LAKES HIGH BEGINS TO FALL TOWARD THE MID-ATLANTIC.
DESCENDING DEWPOINTS ON TAP WILL EVACUATE ANY VESTIGES OF
MUGGINESS LOITERING ACROSS THE CAROLINAS. COMFORTABLY WARM
MAXIMUMS TODAY SHOULD RISE TO 80-84 MOST INLAND LOCALITIES TO
76-79 ALONG THE COAST. THE BRUNSWICK COAST MAY GO WARMER IN THE
NEAR DIRECT OFFSHORE WIND REGIME.
THIS EVENING WINDOW-OPEN TYPE CONDITIONS AS TEMPERATURES COOL TO
70 AND BELOW AFTER THE SUN HAS SUNK BELOW THE HORIZON. COOLING
WILL BRING MINIMUMS INTO DAYBREAK THURSDAY INTO THE MIDDLE 50S
WELL INLAND TO THE UPPER 50S COASTAL INTERIOR TO THE LOW 60S
COASTAL ZONES AMID A NE WIND FLOW.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM WEDNESDAY...HIGH PRESSURE WILL SETTLE DOWN OVER THE
CAROLINAS FROM THE NORTH AS MID TO UPPER RIDGE ALIGNS ITSELF UP
THE EAST COAST THURS INTO FRI. OVERALL EXPECT A RAIN FREE PERIOD
WITH PLENTY OF DRY AIR AND SUBSIDENCE THROUGH THE MID LEVELS OF
THE ATMOSPHERE. MAY SEE SOME FLAT CU DEVELOPING WITH HEATING OF
THE DAY AIDED BY SOME CONVERGENCE ALONG SEA BREEZE BUT STRONG
SUBSIDENCE INVERSION WILL NOT ALLOW MUCH DEPTH TO ANY CU. ALTHOUGH
SUNSHINE SHOULD BE QUITE PLENTIFUL THROUGH THE PERIOD...SOME
HIGHER LEVEL CLOUDS WILL SPREAD INTO THE CAROLINAS OVER THE RIDGE
AS IT SLIPS EAST...ESPECIALLY TOWARD THE END OF THE FRIDAY. THE
CENTER OF THE SFC HIGH WILL SHIFT FURTHER EAST ALSO...OFF THE MID
ATLANTIC COAST BY LATE FRI. THEREFORE DRIER NORTHERLY FLOW WILL
SHIFT TO A GREATER ON SHORE TO S-SE MOISTER RETURN FLOW THROUGH
FRI NIGHT INTO THE WEEKEND AND AIR MASS WILL BEGIN TO MODIFY.
AN OVERALL DRY AIR MASS IN PLACE WILL PRODUCE GREAT DIURNAL
SWINGS WITH LOWER DEWPOINTS DOWN CLOSE TO 50 ALLOWING OVERNIGHT
TEMPS TO DROP OFF QUICKLY DOWN TO THE 50S UNDER MAINLY CLEAR SKIES
AND LIGHT TO CALM WINDS. AFTER A RELATIVELY COOLER START TO THE
DAYS...TEMPS WILL RECOVER TO NEAR SEASONABLE VALUES UNDER MAY
SUNSHINE...INTO THE UPPER 70S MOST PLACES.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 300 AM WEDNESDAY...MID TO UPPER RIDGE WILL SHIFT A LITTLE
BUT OVERALL WILL CONTINUE TO HOLD ON UP THROUGH THE
SOUTHEAST...PRODUCING SUBSIDENCE OVER THE AREA. THE SFC HIGH WILL
CONTINUE TO SLIP FARTHER EAST WHICH WILL PRODUCE A GREATER
SOUTHERLY RETURN FLOW OF MOISTURE WITH DEWPOINT TEMPS REACHING
BACK UP INTO AND THROUGH THE 60S DURING THE WEEKEND INTO EARLY
NEXT WEEK. SOME MID TO HIGH CLOUDS WILL CONTINUE TO RIDE THE COLD
FRONT RUNS FROM NEAR JACKSONVILLE NC TO NEAR WHITEVILLE TO SOUTH
OF FLORENCE SC. THIS IS STILL SLOWER THAN ANY MODEL SHOWED JUST
FIVE HOURS AGO...BUT IT APPEARS THE LATEST HRRR MODEL HAS A
REASONABLE HANDLE ON THE MOVEMENT OF THIS FEATURE OVER THE NEXT
FEW HOURS. THE 00Z GFS APPEARS TO HAVE HAD PROBLEMS THIS MORNING
WITH A TOO-RAPID FRONTAL PASSAGE AND ODD WIND DIRECTIONS
THROUGHOUT THE DAY COMPARED TO THE REST OF THE MODELS. FOR WINDS
AND TEMPERATURES I HAVE STAYED CLOSER THE 00Z NAM AS A RESULT.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 18Z...VFR EXPECTED THROUGH THIS TAF VALID PERIOD. SATELLITE
IMAGES SHOW UPPER CLOUDS HAVE SCATTERED AT KFLO/KLBT AND WILL
SCATTER AT THE COASTAL TERMINALS IN THE NEXT HOUR OR SO. WINDS WILL
BE N-NE THIS AFTERNOON BECOMING E AT THE COASTAL TERMINALS MID TO
LATE AFTERNOON.
WINDS BECOME NE FOR THE OVERNIGHT PERIOD. NO FOG EXPECTED. SCT LOW
CLOUDS AROUND 4K POSSIBLE OVERNIGHT INTO THURSDAY MORNING. WINDS
CONTINUE NE THURSDAY MORNING AS A SOMEWHAT BRISKER PACE THAN TODAY.
EXTENDED OUTLOOK...VFR. ISOLATED SHOWERS SAT BECOMING SCATTERED
SUN. BETTER CHANCES FOR SHOWERS/THUNDERSTORMS MON/TUE.&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1 PM WEDNESDAY...MODERATE NE WINDS SKIPPING ACROSS THE
WATERS BUT NO ADVISORIES OR EXERCISE CAUTION STATEMENTS ARE
PLANNED. WINDS WILL VEER CLOSER TO E MID AND LATE AFTERNOON WITH
ASSISTANCE FROM SEA BREEZE DYNAMICS. SEAS 2 TO 4 FEET OVERALL
WITH DOMINANT PERIODS AROUND 6 SECONDS. NO TSTMS OR RESTRICTIONS
TO VISIBILITY EXPECTED THROUGH TONIGHT. WINDS ENE TONIGHT 10-15
KT...THEN GUSTS TO 20 NEAR DAYBREAK AS HIGH PRESSURE FROM THE
GREAT LAKES BUILDS SE.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM WEDNESDAY...HIGH PRESSURE BUILDING DOWN FROM THE
NORTH WILL SHIFT EAST THROUGH THE PERIOD EVENTUALLY SHIFTING OFF
THE MID ATLANTIC COAST ON FRI. NORTHEASTERLY FLOW UP TO 15 KTS ON
THE FRONT END WILL LIGHTEN AND VEER AROUND BECOMING MORE NORTHEAST
TO EAST THROUGH THURS AND THEN E-SE FRI NIGHT INTO THE WEEKEND.
SEAS WILL BASICALLY REMAIN IN THE 2 TO 4 FT RANGE.
.LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 300 AM WEDNESDAY...HIGH PRESSURE WILL SHIFT OFFSHORE EARLY
IN THE WEEKEND PRODUCING A SOUTHEASTERLY ON SHORE FLOW LESS THAN
15 KTS. A SEA BREEZE WILL DEVELOP EACH AFTERNOON ADDING TO THE SE
PUSH AND PRODUCING GUSTY ON SHORE WINDS AND SOME CHOP IN THE NEAR
SHORE WATERS EACH AFTERNOON. OVERALL EXPECT SEAS IN THE 2 TO 4 FT
RANGE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...MJC
SHORT TERM...RGZ
LONG TERM...RGZ
AVIATION...MRR
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
330 PM CDT WED MAY 13 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 330 PM CDT WED MAY 13 2015
MAIN CHALLENGE TONIGHT WILL BE THE LINGERING PCPN CHANCES. AS OF
LATE AFTERNOON THE WARM FRONT REMAINED ALONG THE INTERSTATE 94
CORRIDOR IN ND AND THE HIGHWAY 10 CORRIDOR IN MN. THE PERSISTENT
SHOWERS/ISOLATED THUNDER CONTINUED JUST NORTH OF THIS SFC
BOUNDARY. REGIONAL RADAR SHOWS THIS LINE EXTENDING FROM NORTH OF
KDLH ALL THE WAY BACK THROUGH KBIS. WATER VAPOR LOOP STILL SHOWS A
COUPLE OF WAVES BACK OVER THE SOUTHWESTERN US WHICH WILL LIFT
NORTHEAST OVER THE NEXT DAY OR TWO. ONE WAVE EJECTS OUT TONIGHT
TOWARD THE KBIS AREA. AT THE SFC IT APPEARS A WEAK LOW SETS UP
OVER WESTERN SD WITH AN INVERTED TROUGH UP THRU KBIS INTO
NORTHEAST ND. STRONG 850MB FLOW CONTINUES TO IMPINGE ON THIS
BOUNDARY. HIGH RESOLUTION MODELS DID NOT HANDLE TODAYS EVENT WELL
AT ALL...AND THEY SET THIS BOUNDARY UP FROM KBIS TO KDVL TONIGHT.
THEREFORE CONFIDENCE NOT ALL THAT HIGH AT THIS POINT. EITHER
WAY...WITH THE POTENTIAL FOR A STAGNANT SFC BOUNDARY AND UPPER
FLOW PARALLEL TO IT...COULD BE SOME PERSISTENT RAIN LIKE THERE WAS
TODAY. HOWEVER IF IT FALLS OVER THE KDVL AREA INTO NORTHEAST ND IT
WOULD FALL WHERE THERE HAS BEEN LESS RAIN. IF IT FALLS FURTHER
SOUTH IT COULD RESULT IN MORE PROBLEMS...AS THAT AREA HAS HAD MORE
RAIN. ON THURSDAY THE MODELS KEEP MOST OF THE RAIN ACROSS
NORTHEAST ND...WITH THE POTENTIAL FOR ANOTHER HEAVIER BAND TO LIFT
UP INTO WEST CENTRAL MN. THIS SECOND BAND WOULD BE SUPPORTED BY
ANOTHER WAVE LIFTING UP INTO THAT AREA AND THE STEADY 850MB JET.
IN BETWEEN THERE COULD BE MORE SPOTTY PCPN. THIS BAND SHOULD
SLOWLY SHIFT EAST THU NIGHT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 330 PM CDT WED MAY 13 2015
FRIDAY LOOKS LIKE THE ONLY DRY DAY AT THIS POINT WITH MORE PCPN
ARRIVING BY FRI NIGHT/SAT. MODELS STILL DIFFER AT THIS POINT WITH
THIS NEXT EVENT...SOME HAVING BROAD PCPN OVER A WIDER AREA AND
SOME TARGETING CENTRAL AND NORTHEAST ND AGAIN.
SATURDAY NIGHT THROUGH WEDNESDAY... ON SATURDAY NIGHT...A STRONG
UPPER LEVEL WAVE WILL BE APPROACHING FROM THE SSW. A LOW PRESSURE
SYSTEM WILL LIKELY EXIST OVER SD WITH AN INVERTED TROUGH INTO
CENTRAL ND AND A WARM FRONT POSSIBLY EXTENDING EAST THROUGH THE RRV.
THE GFS HAS 1000-2000 J/KG OF CAPE WITH AROUND 30 KTS OF DEEP
SHEAR...WHICH POINTS TOWARDS ORGANIZED THUNDERSTORMS. ALSO...THE SPC
HAS THE SOUTHERN CWA INCLUDED IN THEIR DAY 4 SEVERE WEATHER OUTLOOK.
THE ECMWF IS GENERALLY SIMILAR. HAVE INCLUDED A MENTION OF SHOWERS
AND THUNDERSTORMS SATURDAY EVENING...TAPERING OFF TO ISOLATED
THUNDERSTORM COVERAGE AFTER MIDNIGHT. SHOWERS/THUNDERSTORMS WILL
CONTINUE INTO SUNDAY AS THE SURFACE LOW AND UPPER LEVEL SHORT WAVE
MOVE THROUGH THE REGION. THIS WEEKEND WILL LIKELY SEE SIGNIFICANT
RAINFALL CHANCES AGAIN ACROSS THE AREA.
DRY AND COOL HIGH PRESSURE WILL MOVE INTO THE AREA FOR MONDAY. THE
SURFACE HIGH WILL SLOWLY DRIFT THROUGH THE AREA ON TUESDAY...WITH
THE MODELS DIFFERING ON THE UPPER PATTERN BY WEDNESDAY. THE GFS
STARTS TO BRING A LOW PRESSURE SYSTEM ACROSS SD...WHILE THE ECMWF
HAS A MUCH WEAKER FEATURE. THIS UPDATE WILL HAVE SOME PRECIPITATION
IN THE FORECAST FOR MIDWEEK...BUT IF MODELS TREND TOWARD THE
ECMWF...A DRIER FORECAST WILL BE NEEDED WITH THE NEXT UPDATE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 106 PM CDT WED MAY 13 2015
SHOWERS AND ISOLATED THUNDERSTORMS CONTINUE TO EXIST ACROSS SE ND/W
CTRL MN TODAY. LIGHTNING HAS ENDED...SO HAVE CONTINUED WITH JUST
SHRA MENTION AT KFAR. INDIVIDUAL CELLS ARE MOVING ENE...WHILE THE
LINE SLOWLY DRIFTS NORTHWARD. NAM MODEL HAS ENOUGH INSTABILITY TO
SUPPORT THUNDERSTORMS THIS AFTERNOON AT THE ND TAF SITES...BUT BASED
ON CURRENT TRENDS...WILL LEAVE OUT THUNDER MENTION. ALSO HRRR MODEL
BRINGS PRECIP NORTHWARD THROUGH KBJI/KGFK/KTVF THIS AFTERNOON...
TRENDS DON`T FAVOR THIS...SO WILL NOT INLCUDE BUT MONITOR AND UPDATE
AS NEEDED. TONIGHT...CIGS CRASH BACK DOWN AS NEXT LOW PRESSURE
SYSTEM APPROACHES. MAV/MET GUIDANCE BOTH POINT TOWARD IFR CIGS AND
MVFR VIS BY SUNRISE. HAVE INCLUDED IFR CIGS AT MOST SITES AROUND
12Z. SHOWERS ARE EXPECTED LATER TONIGHT...WITH THUNDER NOT LIKELY
BUT A POSSIBILITY IN ND.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
SHORT TERM...GODON
LONG TERM...GODON/KNUTSVIG
AVIATION...KNUTSVIG
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
106 PM CDT WED MAY 13 2015
.UPDATE...
ISSUED AT 1240 PM CDT WED MAY 13 2015
STILL HAVE THE LINE OF SHOWERS ALONG INTERSTATE 94 IN ND AND
HIGHWAY 10 IN MN...AND IT HAS TRANSITIONED MORE TO ISOLATED
THUNDER NOW. OVERALL IT HAS NOT SHOWN MUCH MOVEMENT. LATEST HIGH
RESOLUTION MODELS WANT TO LIFT THIS NORTHWARD...WHICH SO FAR HAS
NOT BEEN HAPPENING. ONLY OTHER ISSUE IS THE STRONGER WIND GUSTS
ACROSS THE FAR SOUTHERN RED RIVER VALLEY. THE STRONGEST WINDS
HAVE BEEN AT KFAR AND ARE LIKELY AIDED BY THE SHOWERS. SEEING SOME
STRONGER WINDS ALSO COMING DOWN THE SISSETON HILLS...WHICH WILL
LIKELY CONTINUE INTO THE AFTERNOON. THEREFORE ISSUED A WIND
ADVISORY FOR A FEW HOURS THIS AFTERNOON. SINCE THE BOUNDARY WITH
THE SHOWERS HAS NOT MOVED MUCH...TEMPS AND CLOUDS ARE HANGING
WHERE THEY ARE AT TOO. IF IT CAN CLEAR ACROSS THE FAR
SOUTH...TEMPS SHOULD RISE QUICKLY THERE.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 325 AM CDT WED MAY 13 2015
ACTIVE PATTERN CONTINUES. FORECAST CHALLENGE CONCERNS
RAIN/THUNDER CHANCES AND TEMPERATURES. MODELS IN PRETTY GOOD
AGREEMENT THROUGH THE PERIOD. WITH NO REAL PREFERENCE WILL USE
BLEND.
CURRENT AREA OF SHRA ASSOCIATED WITH MID LEVEL FRONTOGENETIC
FORCING/ISENTROPIC LIFT LIFTING NE THROUGH THE SW HALF OF THE FA.
AT THIS POINT BAND NOT VERY IMPRESSIVE HOWEVER ALL MODELS SHOW
MORE ORGANIZATION DURING THE COURSE OF THE DAY AS BAND LIFTS NE.
MAIN BAND WILL BE OVER THE NE HALF THIS AFTERNOON HOWEVER THERE
STILL REMAINS SOME LIFT FARTHER TO THE SW CLOSER TO LOW LEVEL
BOUNDARY SO WILL MAINTAIN GENERAL CHANCE POPS. WARM ADVECTION
CONTINUES TO LIFT NORTH WITH WARMEST TEMPERATURES ACROSS THE
SOUTH. DEGREE OF CLOUD COVER WILL HAVE BIG IMPACT ON TEMPERATURES
BUT BEST POTENTIAL FOR SOLAR SHOULD BE ACROSS THE SOUTH WITH
COOLER TEMPERATURES HEADING NE VCNTY CLOUDS PCPN.
MORE SIGNIFICANT SHORT WAVE WILL EJECT NE FROM WESTERN TROUGH
LATER TONIGHT. EXPECT A MORE ORGANIZED AREA OF RAIN TO LIFT NE
LATE TONIGHT THROUGH THURSDAY ALONG AND BEHIND ASSOCIATED SURFACE
LOW AND INVERTED TROUGH. BASED ON BOUNDARY POSITION BEST POTENTIAL
FOR SIGNIFICANT RAINFALL LOOKS TO BE FROM THE WESTERN FA INTO THE
NORTHERN VALLEY. WITH MODEST LOW LEVEL JET CONVERGENCE...SHOWALTERS
SUB ZERO AND A BIT OF ELEVATED CAPE COULD SEE SOME THUNDER MAINLY
FROM VALLEY WEST TONIGHT.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 325 AM CDT WED MAY 13 2015
AS WAVE LIFTS NE PCPN SHOULD END FROM SW TO NORTHEAST THURSDAY
NIGHT. FRIDAY LOOKS TO BE DRY BEFORE RAIN CHANCES RETURN LATE
FRIDAY NIGHT AS UPPER LOW LIFTS NE. TEMPERATURES SHOULD BE CLOSER
TO AVERAGE.
SATURDAY TO TUESDAY...MODELS IN FAIR AGREEMENT WITH THE OVERALL
SYNOPTIC FEATURES...TIMING AND EXACT PLACEMENT STILL TO BE
DETERMINED AND THE MAJOR PLAYER IN PRECIP AMOUNTS. ACTIVE PERIOD
CONTINUES THIS WEEKEND WITH 500MB UPPER LOW AND ASSOCIATED SFC
SYSTEM TO MOVE ACROSS THE NORTHERN PLAINS. SHOWERS AND THUNDERSTORMS
EXPECTED TO DEVELOP IN EARNEST SATURDAY MORNING IN THE SOUTHERN FA
AND LIFT TO THE NORTH WITH STRONG 850MB MOISTURE AND WARM AIR
ADVECTION ON THE NOSE OF THE 40KT SOUTHERLY LOW LEVEL JET. 00Z EC
AND GFS BRING SFC LOW INTO SE ND BY 12Z SUNDAY AND WRAP DEFORMATION
ZONE PRECIP ACROSS THE DEVILS LAKE BASIN SUNDAY. WITH PWATS OVER AN
INCH AND STRONG FORCING IN THE VICINITY OF THE UPPER LOW EXPECTING
ANOTHER EFFICIENT RAIN MAKING SYSTEM AND SIGNIFICANT RAINFALL AMOUNTS
OVER THE SATURDAY TO MONDAY TIME FRAME...1 TO 2 INCHES POSSIBLE WITH
THE HIGHER CONFIDENCE AREA OVER THE DEVILS LAKE BASIN. A FEW SNOW
FLAKES MAY MIX IN SUNDAY NIGHT. TEMPERATURES FOR THE PERIOD WILL BE
WARMEST SATURDAY INTO THE 60S AND 70S. SUNDAY WILL BE DEPENDENT ON
THE PLACEMENT OF THE FRONT WITH 60S AHEAD AND 40S ON THE
BACKSIDE...COOL MONDAY AND TUESDAY IN THE 50S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 106 PM CDT WED MAY 13 2015
SHOWERS AND ISOLATED THUNDERSTORMS CONTINUE TO EXIST ACROSS SE ND/W
CTRL MN TODAY. LIGHTNING HAS ENDED...SO HAVE CONTINUED WITH JUST
SHRA MENTION AT KFAR. INDIVIDUAL CELLS ARE MOVING ENE...WHILE THE
LINE SLOWLY DRIFTS NORTHWARD. NAM MODEL HAS ENOUGH INSTABILITY TO
SUPPORT THUNDERSTORMS THIS AFTERNOON AT THE ND TAF SITES...BUT BASED
ON CURRENT TRENDS...WILL LEAVE OUT THUNDER MENTION. ALSO HRRR MODEL
BRINGS PRECIP NORTHWARD THROUGH KBJI/KGFK/KTVF THIS AFTERNOON...
TRENDS DON`T FAVOR THIS...SO WILL NOT INLCUDE BUT MONITOR AND UPDATE
AS NEEDED. TONIGHT...CIGS CRASH BACK DOWN AS NEXT LOW PRESSURE
SYSTEM APPROACHES. MAV/MET GUIDANCE BOTH POINT TOWARD IFR CIGS AND
MVFR VIS BY SUNRISE. HAVE INCLUDED IFR CIGS AT MOST SITES AROUND
12Z. SHOWERS ARE EXPECTED LATER TONIGHT...WITH THUNDER NOT LIKELY
BUT A POSSIBILITY IN ND.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WIND ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR NDZ039-053.
MN...WIND ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR MNZ003-029.
&&
$$
UPDATE...GODON
SHORT TERM...VOELKER
LONG TERM...JK/VOELKER
AVIATION...KNUTSVIG
AREA FORECAST DISCUSSION
NWS NORMAN OK
412 PM CDT WED MAY 13 2015
.DISCUSSION...
PRIMARY PRECIPITATION SHIELD CONTINUES TO PIVOT EAST THROUGH
CENTRAL AND EASTERN PORTIONS OF THE COUNTY WARNING AREA...
ALTHOUGH CONVECTION IS REDEVELOPING IN THE TEXAS PANHANDLE AND
WEST TEXAS WHICH MAY MOVE INTO WESTERN PORTIONS OF THE AREA THIS
AFTERNOON AND EVENING AGAIN. HRRR AND OUNWRF SHOW THAT THIS MAY
PERSIST FOR A WHILE THIS EVENING IN WESTERN OKLAHOMA/NORTH TEXAS
BUT LIMITED INSTABILITY SHOULD PREVENT STORMS WIDESPREAD STORMS.
OVERALL... STILL EXPECT GENERAL DECREASE IN PRECIPITATION FROM
WEST TO EAST OVERNIGHT AND EARLY TOMORROW MORNING AS SHORTWAVE
MOVES NORTHEAST PAST THE AREA. FLASH FLOOD WATCH STILL LOOKS GOOD
AS THE MODERATE RAINFALL CAN STILL CAUSE FLOODING ISSUES BECAUSE
OF THE HEAVY RECENT RAINFALL.
STORMS EXPECTED AGAIN THURSDAY NIGHT INTO FRIDAY WITH MOISTURE
INCREASE AND PERHAPS A WEAK SHORTWAVE MOVING THROUGH THE AREA. THE
PRIMARY UPPER TROUGH APPROACHES AND INCREASES POPS SIGNIFICANTLY
FRIDAY NIGHT AND SATURDAY. DECENT SIGNAL OF A COMPLEX DEVELOPING
WEST AND MOVING INTO THE AREA SATURDAY MORNING WITH REDEVELOPMENT
EXPECTED AGAIN ON SATURDAY. THERE ARE STILL SOME QUESTIONS ON THE
EXPECTED EVOLUTION ON SATURDAY... BUT STILL WILL BE LOOKING AT THE
SEVERE WEATHER POTENTIAL FOR SATURDAY AS WE GET CLOSER.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 60 80 65 79 / 80 20 30 40
HOBART OK 58 80 62 81 / 50 10 40 30
WICHITA FALLS TX 61 82 65 82 / 50 10 40 40
GAGE OK 55 83 60 82 / 60 10 30 20
PONCA CITY OK 58 80 65 80 / 90 30 20 30
DURANT OK 63 81 66 79 / 80 40 30 50
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...FLASH FLOOD WATCH THROUGH THURSDAY MORNING FOR OKZ007-008-012-
013-017>020-022>048-050>052.
TX...FLASH FLOOD WATCH THROUGH THURSDAY MORNING FOR TXZ083>090.
&&
$$
AREA FORECAST DISCUSSION
NWS MEDFORD OR
247 PM PDT WED MAY 13 2015
.SHORT TERM...WATER VAPOR IMAGERY THIS AFTERNOON SHOWS A DEEP
LONGWAVE TROUGH OVER THE NORTHEAST PACIFIC WATERS EXTENDING INLAND
THROUGH THE FAR WESTERN CONUS. EMBEDDED IN THIS LARGE TROUGH ARE
SEVERAL WELL- DEFINED SHORTWAVE TROUGHS FROM COASTAL CALIFORNIA
NORTH TROUGH EASTERN WASHINGTON. CLOSER TO HOME...WE`RE DEALING
WITH SHORTWAVE ENERGY MOVING SOUTH TO NORTH OVER NORTHERN
CALIFORNIA...AND THIS WILL COMBINE WITH SOME INSTABILITY OVER THE
FORECAST AREA TO GENERATE SHOWERS AND SOME THUNDERSTORMS THIS
AFTERNOON. LATEST HRRR GUIDANCE HAS HELPED US REFINE AREAS FOR
THUNDERSTORM POTENTIAL...AND WE HAVE SPREAD THE CHANCES ALL THE
WAY INTO THE UMPQUA BASIN LATE THIS AFTERNOON BASED ON THIS
OUTPUT. STORMS WILL TRACK SOUTH- SOUTHEAST TO NORTH-NORTHWEST SO
ANY SHOWERS AND STORMS OVER THE SISKIYOUS AND CASCADES HAVE THE
POTENTIAL TO MOVE OVER THE MEDFORD AREA THIS AFTERNOON/EVENING.
TONIGHT...SHORTWAVE ENERGY WILL BE OVERHEAD AND WILL MAINTAIN THE
CHANCE FOR SHOWERS FOR MOST OF THE CWA. WE HAVE DECIDED TO KEEP
THUNDERSTORMS OUT OF THE FORECAST OVERNIGHT BECAUSE IT DOES NOT
SEEM LIKE INSTABILITY ALOFT IS FAVORABLE ENOUGH TO SUPPORT
NOCTURNAL STORMS.
TOMORROW SHOULD BE THE BEST CHANCE FOR THUNDERSTORMS OVER A WIDE
AREA OF SOUTHERN OREGON AND NORTHERN CALIFORNIA. INSTABILITY
INCREASES SUBTLY THROUGH MUCH OF THE ATMOSPHERIC COLUMN TOMORROW AND
SHORTWAVE ENERGY WILL BE OF MODERATE STRENGTH. GFS40 850MB COMPUTED
LIFTED INDICES ARE ZERO OR SLIGHTLY NEGATIVE AND THIS SUPPORTS A
SLIGHT CHANCE OF THUNDERSTORMS. BULK SHEAR FROM 0-6KM IS HIGHER
TOMORROW SO THERE IS A BETTER CHANCE FOR A FEW STRONG STORMS.
ON FRIDAY...THE UPPER LOW THAT`S THE SOURCE OF ENERGY FOR OUR
SHOWERS WILL PUSH INTO NEVADA AND PRECIPITATION CHANCES WILL BE
FOCUSED EAST OF THE CASCADES. THE LOW PROGRESSION CONTINUES EASTWARD
AND BY SATURDAY THERE IS INCREASED STABILITY AND LITTLE TO NO
SHORTWAVE ACTIVITY...SO WE HAVE REMOVED RAIN CHANCES FOR A GOOD
PORTION OF THE FORECAST AREA. IN SHORT...SATURDAY SHOULD BE THE
DRIEST DAY OF THE WEEK.
.LONG TERM...SUNDAY MAY 17TH THROUGH WEDNESDAY MAY 20TH...NOT
MANY CHANGES MADE TO THE LONG TERM. MODELS ARE STILL IN GOOD
AGREEMENT ON A GENERAL LONG WAVE TROUGH PATTERN REMAINING OVER THE
AREA. THIS LENDS TO HIGH CONFIDENCE THAT UNSETTLED WEATHER WILL
CONTINUE THROUGH THE EXTENDED PERIOD. MODELS SHOW MARGINAL
INSTABILITY DURING THE AFTERNOONS AND EVENINGS THROUGH THIS TIME
FRAME AND IS ENOUGH TO WARRANT AT LEAST A SLIGHT CHANCE OF
THUNDERSTORMS OVER THE CASCADES AND EAST SIDE. TEMPERATURES WILL
REMAIN WITHIN A FEW DEGREES OF NORMAL THROUGH THE EXTENDED AND DAY
TO DAY VARIABILITY WILL BE MINIMAL. MND
&&
.AVIATION...FOR THE 13/18Z TAF CYCLE...SHOWERS ARE EXPECTED TO
BECOME MORE WIDESPREAD THIS AFTERNOON, WITH NEARLY ALL TERMINALS
LIKELY TO SEE AT LEAST A SHOWER IN THE VICINITY. WITH THE UNSTABLE
ATMOSPHERE, MOST AREAS SHOULD REMAIN VFR THROUGH THIS EVENING,
ALTHOUGH SOME LOCALIZED AREAS OF MVFR ARE POSSIBLE WITHIN HEAVIER
SHOWERS. THIS EVENING, SHOWERS SHOULD DIMINISH, WHILE MVFR CIGS ARE
LIKELY TO RETURN TO THE COAST AND THE VALLEYS OF THE WEST SIDE FOR
THE OVERNIGHT HOURS. -BPN
&&
.MARINE...UPDATED 230 PM PDT WEDNESDAY, MAY 13, 2015...WINDS WILL
REMAIN WEAK TONIGHT AND PRIMARILY SOUTHERLY. SCATTERED LIGHT SHOWERS
WILL AFFECT THE WATERS THROUGH THURSDAY AFTERNOON AS AN UPPER LOW
CURRENTLY CENTERED ROUGHLY 400 MILES WEST OF VANCOUVER ISLAND TRACKS
SOUTH/SOUTHEASTWARD. NORTHWESTERLY SWELL ASSOCIATED WITH THIS SYSTEM
WILL CONTINUE BUILDING THIS EVENING INTO THURSDAY, CAUSING MODERATE
SEAS. NORTHERLY WINDS WILL INCREASE THURSDAY EVENING, BUT ARE
EXPECTED TO REMAIN BELOW ADVISORY CRITERIA. WINDS WILL BE STRONGEST
SOUTH OF CAPE BLANCO. SEAS BEGIN DIMINISHING THURSDAY NIGHT, AND
WILL REMAIN RELATIVELY CALM THROUGH THE WEEKEND. WINDS WILL REMAIN
NORTHERLY TO NORTHWESTERLY AND MODERATE THROUGH THE WEEKEND. BOTH
13/12Z GFS AND EC SHOW SIMILAR LOW PRESSURE SYSTEMS THIS WEEKEND
FORMING FAR ENOUGH OFFSHORE TO KEEP WINDS BELOW ADVISORY CRITERIA.
-MSC
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
CA...NONE.
PACIFIC COASTAL WATERS...NONE.
$$
NSK/MND/BPN
AREA FORECAST DISCUSSION...UPDATE
NWS PENDLETON OR
1053 AM PDT WED MAY 13 2015
UPDATED FOR MORNING UPDATE AND AVIATION DISCUSSION
.UPDATE...THE SNOW ACROSS THE BLUE MOUNTAINS THIS MORNING WAS
DECREASING AND THE WINTER WARNING WAS CANCELLED. HOWEVER A LARGE
AREA OF PCPN HAD DRIFTED WEST INTO THE COLUMBIA BASIN WHERE LIGHT TO
MODERATE RAIN IS PERSISTING. THIS AREA OF PCPN IS NOW LOCATED
BETWEEN YAKIMA AND PASCO AND SHOULD MOVE LITTLE AND POPS WERE
UPDATED TO REFLECT THIS TODAY. FURTHER SOUTH DAYTIME HEATING MAY
COMBINE WITH THE MOISTURE TO PRODUCE ISOLD TSRA THIS AFTERNOON AND
THE PRESENT SHORT TERM FORECAST APPEARS ON TRACK FOR NOW.
&&
.AVIATION...18Z TAFS...VFR CONDITIONS EXPECTED AT ALL TAF
SITES...EXCEPT FOR KYKM...KPSC...KALW AS THESE SITES MAY BE MVFR
OVER THE NEXT 6 HOURS AS THE AREA OF MODERATE RAIN PUSHES OFF TO THE
NORTHWEST. KYKM WILL SEE THE MOST RAINFALL OVER THE NEXT 6-9
HRS...WHILE KALW AND KPSC SHOULD ONLY SEE RAIN OVER THE NEXT 3 TO 6
HOURS. SPOT SHOWERS STILL POSSIBLE THIS AFTERNOON...DUE TO CLOUD
BREAKS AND A SIGNIFICANTLY MOIST LOW LEVEL. EXPECT SHOWERS TO ENTER
THE KRDM...KBDN AREA AFTER 0Z THURSDAY. THESE SHOWERS WILL LINGER
FOR 3-6 HOURS. WINDS WILL BE 5 TO 15 KTS MAINLY OUT OF THE
WEST...WITH GUSTS UP TO 25 KTS AT TIMES. WEBER
&&
.PREV DISCUSSION... /ISSUED 758 AM PDT WED MAY 13 2015/
UPDATE...THE LATEST RADAR WAS SHOWING A BLOB OF LIGHT TO MODERATE
RAIN OVER THE COLUMBIA BASIN AND HAVE INCREASED POPS OVER THIS
AREA THIS MORNING. MEANWHILE WEB CAMS WERE STILL SHOWING -SN ABOVE
4K IN THE BLUE MOUNTAINS AND ADJUSTED SNOW LEVELS SOME TO INDICATE
THIS. THE PCPN WAS A RESULT OF A STUBBORN LOW PRESSURE SYSTEM OVER
THE TWO STATE AREA WHICH WILL REMAIN STATIONARY OVER WA/OR AND THE
PCPN IS EXPECTED TO CONTINUE MAINLY NORTH OF THE STATE LINE TODAY.
HOWEVER RAP AROUND MOISTURE WILL PERSIST INTO MOSTLY NORTHERN
OREGON TODAY AND THE PRESENT SHORT TERM FORECAST APPEARS ON TRACK
FOR NOW.
PREV DISCUSSION... /ISSUED 300 AM PDT WED MAY 13 2015/
SHORT TERM...TODAY THROUGH THURSDAY NIGHT...AN UPPER LOW CONTINUES
TO ROTATE NORTHEAST ACROSS EASTERN OREGON EARLY THIS MORNING. THERE
IS AN AREA OF HEAVY PRECIP LOCATED TO THE NORTH AND NORTHWEST OF
THIS LOW. THUS HEAVY PRECIP HAS BEEN FALLING FROM NORTHERN GRANT
COUNTY INTO THE BLUE MOUNTAINS, GRANDE RONDE VALLEY, THE BLUE
MOUNTAIN FOOTHILLS, AND LOWER COLUMBIA BASIN EARLY THIS MORNING.
PRECIP AMOUNTS IN THE BLUES AND BLUE MTN FOOTHILLS HAVE BEEN
SUFFICIENT TO PROMPT THE ISSUANCE OF SMALL STREAM FLOOD ADVISORY FOR
THESE AREAS. ALSO SNOW LEVELS HAVE LOWERED IN THE BLUES TO NEAR 4500
FEET, LOCALLY TO 4000 FEET IN THE HEAVIEST PRECIP AREAS. COULD SEE 4
TO 8 INCHES OF SNOW ABOVE 4500 FEET AND HAVE ISSUED A WINTER STORM
WARNING FOR THE NORTHERN OREGON BLUE MOUNTAINS ZONE. THIS MAIN AREA
OF HEAVY PRECIP WILL GRADUALLY LIFT OFF TO THE NORTHWEST THIS
MORNING. THUS WILL KEEP POPS HIGH ACROSS OUR WASHINGTON ZONES
THROUGH THE MORNING. SHOULD SEE A GRADUAL END TO THE PRECIP ACROSS
NORTHEAST OREGON. CENTRAL OREGON WILL BE MOSTLY DRY THIS MORNING.
THE STEADY PRECIP WILL PERSIST OVER KITTITAS COUNTY AND PORTIONS OF
YAKIMA COUNTY INTO THE AFTERNOON. INSTABILITY LOOKS TO RATHER
LIMITED ACROSS OUR OREGON ZONES THIS AFTERNOON, BUT WILL CONTINUE TO
INDICATE ISOLATED TO SCATTERED SHOWERS. ALSO WILL LEAVE A SLIGHT
CHANCE MENTION OF THUNDERSTORMS FROM CENTRAL OREGON EAST TO GRANT
COUNTY AND NORTHEAST TO THE BLUE MOUNTAINS, GRANDE RONDE VALLEY AND
WALLOWA COUNTY. SHOWERS WILL DECREASE ACROSS MUCH OF THE AREA LATE
THIS EVENING AND OVERNIGHT, THOUGH ANOTHER WAVE ROTATING INTO THE
REGION LOOKS TO POTENTIALLY INCREASE SHOWER CHANCES OVER CENTRAL
OREGON LATE TONIGHT INTO THURSDAY MORNING. THIS SAME WAVE WILL
DESTABILIZE THE AIR MASS OVER THE REGION THURSDAY AFTERNOON AND
EVENING WITH VARYING CHANCES OF SHOWERS EXPECTED FOR MOST AREAS.
ALSO A FEW THUNDERSTORMS WILL BE POSSIBLE FOR MANY LOCATIONS. 90
LONG TERM...FRIDAY THROUGH WEDNESDAY...PATTERN WILL BE DOMINATED BY
GENERAL UPPER LEVEL TROUGHINESS THROUGH THE PERIOD. THERE WILL NOT
BE A MAJOR STORM SYSTEM...BUT IT APPEARS THAT THERE WILL BE
UNSETTLED WEATHER THROUGH THE MIDDLE OF NEXT WEEK. THE ATMOSPHERE
WILL BE MARGINALLY UNSTABLE EACH AFTERNOON...AND WITH SUFFICIENT
MOISTURE...SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL
DEVELOP. RIGHT NOW IT APPEARS THAT THE WETTEST DAYS COULD BE MONDAY
AND TUESDAY OF NEXT WEEK BUT THAT WILL CERTAINLY BE SUBJECT TO
CHANGE GIVEN THE WEAK UPPER LEVEL FORCING. THAT BEING SAID...DURING
THE NEXT SEVERAL DAYS SOME AREAS COULD SEE BENEFICIAL RAIN.
TEMPERATURES WILL BE DEPENDENT ON CLOUD COVER BUT SHOULD BE NEAR
NORMAL FOR THIS TIME OF YEAR. 78
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 62 43 67 46 / 90 10 30 30
ALW 63 47 69 50 / 90 10 30 30
PSC 64 46 73 50 / 100 10 20 20
YKM 58 43 70 48 / 90 30 20 20
HRI 66 43 72 50 / 90 10 30 20
ELN 57 42 70 47 / 90 40 20 20
RDM 63 39 61 41 / 30 30 50 40
LGD 60 39 64 46 / 80 20 30 30
GCD 63 38 64 42 / 30 20 50 40
DLS 65 47 71 50 / 60 20 30 30
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
&&
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
97/99/99
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
1158 AM CDT WED MAY 13 2015
.DISCUSSION...BASED ON LATEST RADAR TRENDS AND CONTINUED SLOW-
MOVING CONVECTION OVER MUCH OF SOUTH TEXAS...HAVE DECIDED TO
EXTEND THE FFA UNTIL 5 PM AND MATCH THE TORNADO WATCH. DEPENDING
ON CONVECTIVE TRENDS LATER THIS AFTERNOON...WATCH MAY BE CANCELLED
EARLY (AT LEAST IN SOME AREAS)...AND/OR EXTENDED FOR A FEW MORE
HOURS. MODEL DATA IS NOT SHOWING MUCH AFTER 02Z/03Z (THAT THAT ARE
SHOWING ANYTHING) SO WE WILL SEE WHAT HAPPENS.
&&
.PREV DISCUSSION... /ISSUED 1013 AM CDT WED MAY 13 2015/
DISCUSSION...TORNADO WATCH HAS BEEN ISSUED FOR PORTIONS OF OUR
AREA. UPDATED FORECAST FOR THIS...AND ADJUSTED SOME SHORT TERM
PARAMETERS AS WELL. HAVE NOT LOOKED AT TOO MUCH IN NEW MODEL DATA
AND FORECAST TRENDS...SO DID NOT CHANGE ANYTHING AFTER TODAY.
LOOKS THOUGH THAT THINGS WILL QUIET DOWN A BIT AFTER TODAY...BUT
STILL ENOUGH MOISTURE FOR CONVECTION THROUGH MOST OF THE FORECAST.
NO REAL CHANGES TO THE MARINE. PRODUCTS ARE OUT.
PREV DISCUSSION... /ISSUED 649 AM CDT WED MAY 13 2015/
DISCUSSION...UPDATED FOR 12Z AVIATION.
AVIATION...CONVECTION WILL BE THE MAIN AVIATION CONCERN IN THE
IMMEDIATE TERM AT CRP TERMINAL...AND HAVE INCLUDED TSRA REMARKS.
ADDITIONAL SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE AS THE DAY
PROGRESSES AND HAVE VCTS/TEMPO TSRA AT ALL TERMINALS. IF
THUNDERSTORMS DIRECTLY IMPACT THE TERMINALS THEN REDUCED VSBYS AND
ERRATIC WINDS WILL BE POSSIBLE. OUTSIDE OF THUNDERSTORMS WINDS
WILL GENERALLY BE OUT OF THE EAST AND SOUTHEAST.
PREV DISCUSSION... /ISSUED 440 AM CDT WED MAY 13 2015/
SHORT TERM (TODAY THROUGH THURSDAY)...THE FORECAST IS NOT EASY.
AS OF WRITING...A THIN AXIS CONTAINING DEEPEST MOISTURE WAS
LOCATED ALONG AND JUST OFFSHORE OF THE MIDDLE TEXAS COAST.
MODEST...BUT GRADUALLY STRENGTHENING...LOW LEVEL MOISTURE
ADVECTION WAS OCCURRING INTO THE AREA OF DEEPER MOISTURE.
THIS...IN ADDITION TO AN APPROACHING H5 VORT MAX...HAS LED TO
SIGNIFICANT SHOWERS AND THUNDERSTORMS PERSISTING OVER THE PAST
SEVERAL HOURS ACROSS THE NEARSHORE WATERS. AFTER COLLABORATION
WITH THE SATELLITE PRECIPITATION ANALYSIS BRANCH ABOUT WHERE HEAVY
RAINFALL POTENTIAL MAY OCCUR...HAVE DECIDED TO EXPAND FLASH FLOOD
WATCH INTO THE NORTHERN COASTAL BEND TO ACCOUNT FOR POTENTIAL OF
DEEPER MOISTURE AXIS SHIFTING NORTHWARD...WHICH COULD LEAD TO
HOURLY RAINFALL RATES OF 1 TO 3 INCHES. ELSEWHERE
INLAND...ISOLATED TO SCATTERED CONVECTION IS GRADUALLY DEVELOPING
IN RESPONSE TO A STRENGTHENING ESE 925MB LLJ. RAP MID LEVEL
HEIGHT ANALYSIS OVERLAID WITH WATER VAPOR IMAGERY INDICATES AN
APPROACHING MID LEVEL S/W TROUGH WHICH SHOULD AID IN CONVECTIVE
DEVELOPMENT ALONG THE RIO GRANDE BY SUNRISE. THE OVERALL FORECAST
FOR TODAY CALLS FOR CONVECTION ALONG THE COAST TO PERSIST AND
BUILD NORTHWARD THROUGH MID MORNING WITH ADDITIONAL CONVECTION
DEVELOPING/EXPANDING IN AREAL COVERAGE ALONG THE RIO GRANDE AND
BEGIN TO SHIFT NE. LOCALLY HEAVY RAINFALL WILL BE POSSIBLE PRETTY
MUCH ANYWHERE TODAY AS PWATS REMAIN HIGH. A STRONG STORM WILL BE
POSSIBLE ACROSS THE REGION GIVEN EXPECTED MLCAPE VALUES AROUND
2000 J/KG AND SUFFICIENT BULK SHEAR VALUES /ESPECIALLY ACROSS NW
COUNTIES/. MAIN MID LEVEL TROUGH AXIS SWINGS THROUGH THE AREA BY
LATE TODAY RESULTING IN DRIER CONDITIONS TONIGHT. CAVEAT IS THAT A
A MINOR S/W TROUGH MAY PUSH ACROSS TONIGHT WHICH MAY LEAD TO
ADDITIONAL CONVECTIVE CHANCES...ESPECIALLY ACROSS SOUTHERN ZONES.
GUIDANCE INDICATES SOME DRIER AIR AT H85 BUILDING INTO THE REGION
ON THURSDAY RESULTING IN LOWER PRECIP CHANCES.
WILL ALLOW RIP CURRENT RISK TO EXPIRE AT 6 AM. A MODERATE RISK OF
RIP CURRENTS WILL EXIST TODAY AND MAY FLIRT WITH THE HIGH RISK
THRESHOLD AGAIN ON THURSDAY.
LONG TERM (THURSDAY NIGHT THROUGH TUESDAY)...AN UPPER LEVEL
DISTURBANCE WILL MOVE OUT OF MEXICO THURSDAY NIGHT INTO FRIDAY.
THIS WILL LEAD TO CONTINUED CHANCES OF SHOWERS AND STORMS OVER THE
WEST THURSDAY NIGHT...SHIFTING TO THE NORTHERN SECTIONS ON FRIDAY.
RAIN CHANCES MAY TEMPORARILY LOWER ON SATURDAY THE SHORTWAVE
TROUGH PASSES OFF TO THE NORTHEAST. WILL KEEP SOME LOW END 20 POPS
THOUGH WITH LINGERING MOISTURE ACROSS SOUTH TEXAS. ACTIVE WEATHER
PATTERN APPEARS TO RETURN BEGINNING SUNDAY THROUGH THE FIRST PART
OF NEXT WEEK. SOUTHWEST FLOW ALOFT WITH OCCASIONAL UPPER
DISTURBANCES WILL TRAVERSE THE REGION DURING THIS TIME. SUPERBLEND
POPS GENERALLY RANGE FROM 30 TO 50 PERCENT...AND WILL KEEP
OFFICIAL FORECAST SIMILAR TO SUPERBLEND NUMBERS. TEMPERATURES IN
THE 80S WILL BE COMMON THROUGH THE PERIOD...WITH LOWER 90S OVER
THE WESTERN ZONES FRIDAY THROUGH SUNDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 83 74 86 75 84 / 60 30 30 20 30
VICTORIA 81 72 88 73 83 / 70 40 30 20 40
LAREDO 85 72 91 73 90 / 60 20 20 30 30
ALICE 85 72 89 73 86 / 60 20 30 20 30
ROCKPORT 83 76 85 76 80 / 60 30 20 20 30
COTULLA 82 70 89 71 87 / 70 20 20 40 30
KINGSVILLE 86 74 88 75 86 / 60 30 30 20 30
NAVY CORPUS 83 75 84 76 81 / 60 30 20 20 30
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...FLASH FLOOD WATCH UNTIL 5 PM CDT THIS AFTERNOON FOR THE
FOLLOWING ZONES: ARANSAS...BEE...CALHOUN...DUVAL...GOLIAD...
JIM WELLS...KLEBERG...LA SALLE...LIVE OAK...MCMULLEN...
NUECES...REFUGIO...SAN PATRICIO...VICTORIA...WEBB.
GM...NONE.
&&
$$
GW/86...SHORT TERM