Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 05/01/13
AREA FORECAST DISCUSSION
NWS TAUNTON MA
724 PM EDT TUE APR 30 2013
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN PARKED OVER NEW ENGLAND FOR THE
REMAINDER OF THE WORK WEEK AND INTO THE WEEKEND. THIS WILL BRING
SEASONABLY MILD DAYS...COOL NIGHTS...AND LITTLE...IF ANY...
APPRECIABLE RAINFALL. A BACKDOOR COLD FRONT WILL MOVE THROUGH
THURSDAY NIGHT...BRINGING CHILLY WEATHER TO THE COAST FRI AND SAT.
TEMPS WILL THEN MODERATE SOME BY EARLY NEXT WEEK...BUT NO
APPRECIABLE RAINFALL IS EXPECTED.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
730 PM UPDATE...
CONCERNING OVERNIGHT TEMPERATURES...LOW TO MID 20 DEWPOINTS WITH
THE EXPECTATION OF MOSTLY CLEAR CONDITIONS UNDER LIGHT AND
VARIABLE WINDS ACROSS INTERIOR NEW ENGLAND PRESENTS FAVORABLE
CONDITIONS FOR RADIATIONAL COOLING. AM EXPECTING SUB-FREEZING
TEMPERATURES WITHIN INTERIOR VALLEYS. PATCHY FROST IS LIKELY. AS
PREVIOUS FORECASTER MENTIONED...TEMPERATURES WILL FALL VERY
QUICKLY AFTER SUNSET WITH THE DRY AIRMASS IN PLACE ALONG WITH
LIGHT WINDS AND MAINLY CLEAR SKIES. LOWS IN THE LOW-MID 30S ACROSS
THE INTERIOR...WITH UPPER 30S TO LOW 40S ALONG THE IMMEDIATE COAST
AND WITHIN URBAN AREAS.
GROWING SEASON ONLY APPLIES TO SOUTH-COASTAL ZONES OF RHODE
ISLAND AND MASSACHUSETTS WHERE TEMPERATURES ARE FLIRTING WITH 36
DEGREES...AND IN ADDITION LOW CLOUDS AND EASTERLY ONSHORE WINDS
MAY PREVENT TEMPERATURES FROM FALLING TO FROST ADVISORY CRITERIA.
MAIN AREA TO WATCH CLOSELY WILL BE CENTRAL-INTERIOR BRISTOL AND
PLYMOUTH COUNTIES OF MASSACHUSETTS WHERE IT GOT DOWN TO FREEZING
THE PREVIOUS NIGHT. PRESENT DEWPOINTS IN THIS AREA WERE MILDER
TODAY THAN YESTERDAY.
AS TO CLOUDS...WATCHING THE LOW DECK OFF THE COASTLINE. HAVE
FAVORED THE RAP WITH THE DECK COMING IN TOWARDS MORNING ACROSS
THE CAPE AND ISLANDS. ANTICIPATING 800 FOOT CEILINGS WITH MODEST
EASTERLY FLOW ACTING TO PREVENT FOG FORMATION. CAN NOT RULE OUT AT
LEAST SOME REMOTE POSSIBILITY...THERE ARE HINTS OF PATCHY DENSE
FOG OVER THE WATERS THAT MAY ROLL IN ONSHORE.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
WEDNESDAY...
ANOTHER GEM OF A DAY WITH DEEP LAYER RIDGE IN PLACE AND ASSOCIATED
SUBSIDENCE YIELDING ABUNDANT SUNSHINE. NO AIRMASS CHANGE SO
EXPECTING SIMILAR TEMPS/HIGHS TOMORROW...L70S AWAY FROM THE COAST.
WARM ALONG THE COAST THEN TEMPS FALLING THROUGH THE 60S AND
POSSIBLY INTO THE 50S LATER IN THE DAY WITH AFTN SEABREEZES.
COULD BE SOME MORNING FOG AND STRATUS ACROSS CAPE COD AND THE
ISLANDS BUT THE HIGH/STRONG MAY SUNSHINE SHOULD BURN THE LOW
CLOUDS OFF QUICKLY.
WED NIGHT...
NOT MUCH CHANGE WITH RIDGE OVER THE AREA. TEMPS FALL FAIRLY
QUICKLY WITH SUNSET GIVEN DRY AIRMASS IN PLACE ALONG WITH LIGHT
WINDS AND MAINLY CLEAR SKIES.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
* COLD FRONT THURSDAY NIGHT INTO FRIDAY WITH SPOTTY SHOWERY WEATHER
* OTHERWISE CONTINUED DRY AND MILD WITH EASTERLY ONSHORE FLOW
*/OVERVIEW AND MODEL CONSENSUS...
BROAD OMEGA BLOCKING PATTERN RESONATES THROUGH THE ENTIRE FORECAST
PERIOD LEAVING THE NORTHEASTERN CONUS UNDER THE INFLUENCE OF HIGH
PRESSURE. THERE ARE SUBTLE DIFFERENCES IN THE PATTERN BY THE WEEKEND
AND BEYOND BETWEEN THE ECMWF/GFS/CANADIAN THAT RESULT IN SIGNIFICANT
OUTCOMES INTO NEXT WEEK. EVALUATING THE SYNOPTIC PATTERN...HAVE MORE
FAVORIBILITY TOWARDS THE ECMWF AND WILL TEND THE GREATEST WEIGHT
TOWARDS THAT SOLUTION.
*/DAY-TO-DAY DETAILS...
*/THURSDAY AND BEYOND...
THE ONLY WEATHER APPEARS TO FOCUS ON THURSDAY NIGHT INTO FRIDAY
DURING WHICH TIME A SHARP SHORTWAVE DISTURBANCE ROUNDING THE BROADER
LOW OVER THE CENTRAL ATLANTIC USHERS A BACK-DOOR COLD FRONT ACROSS
THE REGION. COULD SEE SOME LIGHT SCATTERED SHOWER ACTIVITY ALONG THE
FRONT CONSEQUENTIAL OF DEEP-LAYER FORCING OF RESIDUAL MOISTURE.
MODEST 15-20 MPH NORTHEAST WINDS TO THE REAR OF THE FRONT WITH GUSTS
AROUND 25 MPH LEADING TO MARINE HEADLINES OVER THE WATERS. WINDS
SHOULD LIMIT SUB-FREEZING TEMPERATURES AND SUBSEQUENT FROST/FREEZE
HEADLINES...BUT A MUCH COOLER AIRMASS WILL BUILD ACROSS THE REGION
LENDING TO A CHILLY DAY ON FRIDAY.
BUT AS TO THE REST OF THE FORECAST PERIOD...WILL SEE A SLIGHTLY
WOBBLING ELONGATED AREA OF HIGH PRESSURE ACROSS THE NORTHEASTERN
CONUS. AN EASTERLY COMPONENT OF FLOW MAINTAINS THROUGH THE ENTIRE
ATMOSPHERIC COLUMN...WITH CONTINUAL ADVECTION OF COOLER AIR OFF THE
OCEAN AT THE SURFACE /CHILLY ALONG THE IMMEDIATE SHORES WHILE
REMAINING SEASONABLE IN THE 60S TO LOW 70S OVER THE INTERIOR/.
WHILE SPECIFICITY IS DIMINISHED FURTHER IN TIME WITH THE FORECAST
PERIOD...IT IS LIKELY THAT WITH EACH DAY WE MAY NEED TO CONSIDER THE
FOLLOWING:
- FIRE WEATHER HAZARDS ACROSS THE INTERIOR
- POTENTIAL FOR LOWS NEAR SUB-FREEZING TEMPERATURES
- LOW CLOUDS AND POTENTIAL FOR COASTAL FOG /MAINLY OVERNIGHT/
- MARINE WEATHER HEADLINES OVER THE WATERS
&&
.AVIATION /23Z TUESDAY THROUGH SUNDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
OVERVIEW...HIGH CONFIDENCE.
VFR. ONLY MAIN CONCERN IS ACROSS THE CAPE AND ISLANDS WHERE EAST
WINDS WILL BE MODEST OVERNIGHT DRAWING AN IFR STRATUS DECK AROUND
800 FT AGL OFF THE WATERS. DENSE PATCHY FOG WILL BE POSSIBLE AS
WELL BUT HAVE LESSER CONFIDENCE. DECK ERODES ACROSS THE CAPE AND
ISLANDS INTO LATE MORNING WEDNESDAY. REMAINDER OF FORECAST
EXHIBITS LIGHT WINDS AND MOSTLY CLEAR CONDITIONS...MIDDAY TO
AFTERNOON SEA-BREEZES ALONG THE SHORES.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF. AFTN SEABREEZE AGAIN
TOMORROW.
KBDL TERMINAL...HIGH CONFIDENCE IN TAF. VFR ALONG WITH LIGHT
WINDS.
OUTLOOK...THURSDAY THROUGH SATURDAY...
MODERATE CONFIDENCE.
WILL HAVE TO DEAL WITH SOME SCT -SHRA THURSDAY NIGHT AS A COLD FRONT
SWEEPS ACROSS THE TERMINALS. LIKELY BEHIND THE FRONT WE WILL SEE
NORTHEAST WINDS SUSTAINED 10-15 KTS WITH GUSTS AROUND 25 KTS
/ESPECIALLY CLOSER TO THE SHORES/ CONTINUING INTO FRIDAY.
FOR THE WEEKEND...EASTERLY COMPONENT OF FLOW DOMINATES. THERE IS THE
POTENTIAL FOR LOW CLOUDS TO SNEAK IN FROM THE EAST. CHANCES FOR
COASTAL FOG WILL BE POSSIBLE DURING THE OVERNIGHT PERIODS. IN SUCH
CASES...IFR CONDITIONS ARE PLAUSIBLE.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
HIGH CONFIDENCE THROUGH WEDNESDAY NIGHT.
FINE BOATING WEATHER WITH HIGH PRES OVER THE EASTERN SEABOARD.
LIGHT WINDS AND 3 FT/13 SECOND EAST-SOUTHEAST SWELL ERODES WITH
TIME. ONLY WRINKLE TO THE FORECAST WILL BE POSSIBLE LOW
CLOUDS/STRATUS AND LOWER VSBY LATE TONIGHT AND EARLY WED MORNING
ACROSS THE WATERS OF NANTUCKET AND CAPE COD. THIS SHOULD BURN OFF
BY MIDDAY YIELDING BETTER VSBY. OTHERWISE QUIET WEATHER PREVAILS.
OUTLOOK...THURSDAY THROUGH SATURDAY...
MODERATE CONFIDENCE.
WILL LIKELY HAVE TO HOIST SMALL CRAFT ADVISORY HEADLINES FOR
THURSDAY NIGHT INTO FRIDAY AS A COLD FRONT OUT OF THE NORTH SWEEPS
ACROSS THE WATERS BEHIND WHICH WINDS WILL BE SUSTAINED AROUND 10-15
KTS WITH GUSTS AROUND 25 KTS. WILL SEE SEAS BUILD 5-6 FEET OVER THE
OUTER WATERS.
WINDS WILL RELAX OVER THE WEEKEND WITH A CONTINUED EASTERLY
COMPONENT...WITH WAVES SUBSIDING SLIGHTLY LONGER. MAY NEED TO
PROLONG SMALL CRAFT ADVISORY HEADLINES FOR SEAS...OTHERWISE BOATING
CONDITIONS SHOULD IMPROVE.
&&
.FIRE WEATHER...
NO MAJOR CHANGES TO THE FIRE WEATHER FORECAST THROUGH THE WEEK.
OTHER THAN A BRIEF ISOLATED SHOWER THU EVENING DRY WEATHER
CONTINUES UNTIL FURTHER NOTICE. HOWEVER WINDS WILL REMAIN LIGHT
TOMORROW AND THU...THEN PICK UP THU NGT INTO FRI BEHIND BACK DOOR
FRONT. HOWEVER WITH THE WIND SHIFT TO THE NORTHEAST RH VALUES WILL
INCREASE TO AROUND 50 PERCENT FRI. SO WHILE WINDS PICKUP THU NGT
INTO FRI...INCREASING RH VALUES INCREASE AS WELL.
THE EXTENDED PERIOD OF DRY WEATHER WILL CONTINUE INTO EARLY NEXT
WEEK. MINIMUM AFTERNOON RELATIVE HUMIDITIES WILL CONTINUE TO DROP
INTO THE 20 TO 40 PERCENT RANGE INLAND FROM THE COAST FOR MUCH OF
THE WEEK. WINDS WILL GENERALLY REMAIN BELOW FIRE WEATHER HEADLINE
CRITERIA GIVEN UPPER LEVEL RIDGING.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...NOCERA/SIPPRELL
NEAR TERM...NOCERA/SIPPRELL
SHORT TERM...NOCERA
LONG TERM...SIPPRELL
AVIATION...NOCERA/SIPPRELL
MARINE...NOCERA/SIPPRELL
FIRE WEATHER...NOCERA
AREA FORECAST DISCUSSION
NWS NEW YORK NY
527 AM EDT MON APR 29 2013
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN ANCHORED FROM THE CANADIAN MARITIMES
THROUGH THE NEW ENGLAND COAST THROUGH THE WEEKEND...WHILE WEAK LOW
PRESSURE PASSES TO THE SOUTH ACROSS THE MID ATLANTIC STATES
TODAY AND TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
RAIN ASSOCIATED WITH WEAKENING MID LEVEL SHORTWAVE HAS MOVED INTO
WESTERN ZONES...AND IS MAKING SLOW PROGRESS EASTWARD DUE TO
DOWNSTREAM RIDGING AND SUBSIDENCE. DECREASE POPS TO CHC ACROSS
INTERIOR LOWER HUDSON VALLEY LOCATIONS AS LATEST RADAR TRENDS AND
MODEL GUIDANCE INDICATE THAT IT SHOULD BE MORE SCATTERED IN NATURE
FROM HERE ON OUT. SFC HIGH OFF THE NEW ENGLAND COAST IS EXPECTED
TO LIFT A BIT TO THE NORTH TODAY WHICH WILL ALLOW THE RAIN TO
GRADUALLY SPREAD EASTWARD. TOUGH PART OF THE FORECAST IS HOW FAR
THE PCPN GETS AND WHEN THE DRIER AIR ASSOCIATED WITH THE HIGH
BUILDS BACK IN SHUNTING IT TO THE S AND W. GFS IS AGGRESSIVE
BRINGING THE DRY AIR BACK BY AFTN AND KEEPING ALL PCPN S AND W OF
THE FORECAST AREA THROUGH TUE. MOST OF THE OTHER MODEL GUIDANCE
HOLDS ON TO IT THROUGH AT LEAST THIS EVE. MOST OF THE GUIDANCE WAS
TOO SLOW BRINGING THE PCPN INTO NE NJ AND THE LOWER HUDSON VALLEY
INCLUDING THE WRFNMM/WRFARW AND RUC. THE HRRR HAS BEEN HANDLING
THE SITUATION WELL AND KEEPS PCPN THROUGH THE DAY...ALTHOUGH IT
MAY BE BRINGING IT TOO FAR E (LI FORKS).
ALL THAT SAID...HAVE HIGHEST POPS THIS MORNING AND IN THE WESTERN
THIRD OF THE CWA. WISH THERE WAS MORE CONSISTENCY WITH THE POPS
THIS AFTN AND EVE...BUT HAVE LOW CONFIDENCE IN TIMING...DURATION
AND LOCATION OF PCPN DURING THIS TIME.
HIGHS WILL LIKELY BE A FEW DEGREES WARMER IN EASTERN ZONES WITH
THE EXPECTATION THAT RAIN DOESN`T MAKE IT THAT FAR EAST. HAVE
FORECASTED LOWER 60S ACROSS THE WESTERN HALF OF THE AREA AND MID
TO UPPER 60S EAST...BUT AGAIN WILL ULTIMATELY DEPEND ON WHERE THE
PRECIP COMES TO A HALT.
LOWS TONIGHT ALSO FOLLOW THE AFOREMENTIONED IDEA WITH COOLER TEMPS
EAST WITH CLEARING OCCURRING THERE FIRST AND A FEW DEGREES WARMER
WEST WITH MORE CLOUD COVER.
&&
.SHORT TERM /TUESDAY/...
KEPT A FEW HOURS OF SCHC POPS ACROSS W ZONES TUE MORNING FOR ANY
STRAY AREAS OF RAIN THAT MAY REMAIN. OTHERWISE...RIDGING BUILDS
BACK TO THE W WITH DRY WEATHER AND CLEARING SKIES. WESTERN AREAS
MAY NOT SEE A WHOLE LOT OF SUNSHINE DURING THE DAY WITH THE
DISTURBANCE TO THE SW...HOWEVER STILL EXPECT SLIGHTLY WARMER MAX
TEMPS THAN ON MONDAY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
CONDITIONS CONTINUE TO LOOK MOSTLY DRY AND QUIET WEDNESDAY THROUGH
THE COMING WEEKEND WITH SURFACE HIGH PRESSURE SITTING OVER THE
NORTHEAST AND UPPER LEVEL RIDGING BUILDING ALOFT.
AS THE RIDGE BUILDS TUES NIGHT INTO WED...A WEAK SHORTWAVE WITH THE
ASSOCIATED VORT MAX LOOKS TO PASS OVER THE FAR WESTERN REGIONS OF
THE CWA. THIS COULD TRIGGER VERY LIGHT PCPN OVER PORTIONS OF NJ
THROUGH THE NIGHT TUES...THOUGH WITH BUFKIT SOUNDINGS INDICATING A
FAIRLY DRY VERTICAL PROFILE...PSBL THAT NO PCPN ACTUALLY OCCURS.
WILL KEEP ONLY LOW END SLIGHT CHC POPS.
THE RIDGE BUILDS AND TAKES HOLD OF THE REGION BY THURS. SOME MODEL
DIFFERENCES ON THE EXTENT OF THE RIDGE AND PLACEMENT...WITH THE 00Z
NAM AND ECMWF BOTH KEEPING THE RIDGE SLIGHTLY FARTHER WEST...AND
THUS ALLOWING MULTIPLE SHORTWAVES TO PASS WITHIN THE VICINITY OF THE
AREA. HOWEVER...WITH LOW CONFIDENCE OF THE SETUP...WILL CONTINUE A
DRY FORECAST THROUGH THE WEEKEND.
THE NEXT CONCERN WILL BE A DEVELOPING CLOSED LOW ALOFT...WITH THE
MODELS NOW SEEMING TO TREND TO A SLIGHTLY SLOWER SOLUTION...KEEPING
IT OVER THE CENTRAL US THROUGH THE WEEKEND. DID BRING IN SLIGHT CHC
POPS AGAIN FOR THE END OF THE FORECAST...THE BEGINNING OF NEXT
WEEK...TO ACCOUNT FOR THE RIDGING PUSHING OFF TO THE EAST...AND
MULTIPLE MORE SHORTWAVES PASSING THROUGH THE REGION.
LITTLE TEMPERATURE VARIATIONS THROUGH THE PERIOD...WITH HIGHS
GENERALLY IN THE 60S TO LOWER 70S...AND OVERNIGHT LOWS IN THE 40S.
ONSHORE FLOW WILL KEEP COASTAL REGIONS COOLER...WITH THE HIGHER
TEMPS OVER INTERIOR NY...AND CT. USED A BLEND OF WPC/MOS FOR TEMPS
AND DEW PTS.
&&
.AVIATION /10Z MONDAY THROUGH FRIDAY/...
HIGH PRESSURE WILL REMAIN ANCHORED FROM THE CANADIAN MARITIMES
THROUGH THE GULF OF MAINE OVER THE NEXT SEVERAL DAYS.
PERIODS OF LIGHT RAIN WILL IMPACT WRN TERMINALS TODAY. THIS
ACTIVITY HOWEVER LOOKS TO REMAIN VFR. THERE IS A LOW POTENTIAL FOR
A FEW POCKETS OF MVFR THIS AFTN.
ONE OF THE MODELS DOES PROG MORE RAIN AND MVFR/IFR POTENTIAL FOR
TNGT. THIS IS THE RESULT OF CONVECTIVE ENHANCEMENT OF SHRA S OF OUR
AREA TODAY. ALTHOUGH THIS SCENARIO IS A LOW PROBABILITY...THERE IS
A SMALL CHC THAT SIGNIFICANT CHANGES TO THE TAFS ARE POSSIBLE FOR
TNGT.
S FLOW WILL BACK TO THE SE BY 14Z. THE SE FLOW WILL THEN REMAIN IN
PLACE THRU MOST OF TNGT. WIND SPEEDS INCREASE TO 10-15KT BY
18Z...THEN DECREASE AGAIN AFT 00Z.
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)
KEWR FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES
SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KJFK FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.
KLGA FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.
KTEB FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.
KHPN FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.
KISP FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.
.OUTLOOK FOR 06Z TUE THROUGH FRI...
.MON NGT...MAINLY VFR. MVFR OR LOWER POSSIBLE IS RAIN IS MORE
EXTENSIVE THAT EXPECTED ATTM.
.TUE-FRI...MAINLY VFR. MVFR OR LOWER CONDS POSSIBLE EACH NIGHT AND
MORNING.
&&
.MARINE...
SUB-ADVSY CONDS ARE EXPECTED ON THE WATERS THROUGH TUE WITH SELY
WINDS BACKING TO THE E AS RETREATING HIGH PRES BUILDS BACK DOWN
FROM THE NE TONIGHT AND TUE. WINDS INCREASE A BIT TONIGHT WITH A
TIGHTENING PRES GRADIENT AND GUSTS MAY APPROACH SCA LEVELS
TONIGHT IF THERE IS SOME MIXING...BUT WOULD ONLY EXPECT OCNL
GUSTS UP TO 25 KT AT BEST. ELY SWELL ALSO CONTINUES AND ALTHOUGH
WINDS WILL BE RELATIVELY LIGHT...EXPECT THE COMBINATION OF WIND
WAVES AND SWELL TO INCREASE SEAS TO AROUND 4 FT ON THE OCEAN
WATERS TUE MORNING.
GENERALLY SUB-SCA CONDITIONS ON ALL WATERS
MID WEEK THROUGH THE BEGINNING OF NEXT WEEK. A PERSISTENT EASTERLY
FLOW COULD BUILD THE OCEAN SEAS UP TO 5 FT FOR A PERIOD WED NIGHT
INTO THURS. SEAS COULD REACH 5 FT AGAIN OVER THE COMING WEEKEND
WITH INCREASED NELY FLOW FROM THE INTERACTION BETWEEN THE SITTING
HIGH...AND LOW PRESSURE TO THE SOUTH.
&&
.HYDROLOGY...
A THIRD OF AN INCH OF RAINFALL IS POSSIBLE ON AVERAGE ACROSS NYC
AND POINTS WEST MON/MON NIGHT...WITH LESSER AMOUNTS TO THE EAST.
NO SIGNIFICANT PRECIPITATION IS EXPECTED TUESDAY THROUGH SUNDAY.
&&
.EQUIPMENT...
RIVERHEAD NY NOAA ALL HAZARDS RADIO TRANSMITTER IS OUT OF SERVICE.
RETURN TO SERVICE TIME UNKNOWN ATTM.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS ALBANY NY
130 AM EDT MON APR 29 2013
.SYNOPSIS...
HIGH PRESSURE HAS RETREATED TO THE EAST. AN BAND OF SHOWERS WAS
ATTEMPTING TO MOVE INTO AREAS WEST OF THE HUDSON. SCATTERED SHOWERS
WILL WORK INTO MOST AREAS ON MONDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1230 PM EDT...WENT AHEAD AND RAISED OVERNIGHT LOW TEMPERATURES
A FULL CATEGORY (3 DEGREES) ACROSS THE BOARD. CLOUDS WERE IN TO
STAY...AND MOST AREAS NOW HAD A BREEZE 5 TO 10 MPH FROM THE
SOUTH...AND IN SOME CASES GUSTING TO OVER 20 MPH. THESE TWO FACTORS
(CLOUDS AND BREEZE) WILL KEEP TEMPERATURES FROM FALLING A WHOLE LOT
MORE OVERNIGHT.
WATCHING A BAND OF SHOWERS NEAR I-81 BUT AS THEY MOVE INTO DRY AIR
HAVE HAD A HARD TIME MOVING EAST. THE EXPERIMENTAL HRRR EARLIER
INDICATED SHOWERS WOULD MOVE INTO THE CAPITAL DISTRICT BY SUNRISE.
HOWEVER...THE LATEST VERSION HAS BACKED OFF THIS ARRIVAL TIME UNTIL
AFTER SUNRISE...WHICH GENERALLY AGREED WITH THE 00Z AND INCOMING 00Z
GFS. FOR NOW...MADE NO CHANGES IN THE POP FIELDS.
SO FOR THE REST OF OVERNIGHT...IT WILL STAY RELATIVELY MILD WITH
LOWS AROUND 50 IN THE GREATER CAPITAL DISTRICT....MID OR UPPER 40S
MOST OTHER PLACES. THE SOUTH BREEZE WILL CONTINUE AND LIGHT
SCATTERED SHOWERS WILL SLOWLY WORK TO THE WEST OF THE HUDSON
BRINGING UNDER A TENTH OF AN INCH OF RAINFALL. IT SHOULD REMAIN DRY
FROM THE HUDSON VALLEY ON EASTWARD ALTHOUGH CLOUDS WILL THICKEN.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY/...
SOME QUITE NOTICEABLE DISCREPANCIES IN SOURCES OF GUIDANCE THROUGH
THE PERIOD...ESPECIALLY IN THE TOMORROW NIGHT THROUGH WEDNESDAY
TIME FRAME. UNTIL THEN...THE WEAKENING UPPER DISTURBANCE IS
EXPECTED TO WASH OUT...WITH THE EASTERN EXTENT OF THE AREA OF
SHOWERS A BIT IN QUESTION. THE BATTLE BETWEEN THE RIDGING OFF
CANADA AND THE ADVANCING MOISTURE IN THE WEAKENING UPPER
DISTURBANCE SHOULD SUPPORT SOME AREA OF SCATTERED SHOWERS ALONG
AND WEST OF THE HUDSON VALLEY...WITH ONLY ISOLATED ACTIVITY EAST
OF THE HUDSON VALLEY INTO WESTERN NEW ENGLAND. SOME PARTS OF
WESTERN NEW ENGLAND MAY NOT SEE ANY RAIN THROUGH WEDNESDAY
DEPENDING ON HOW THE WEAKENING UPPER DISTURBANCE EVOLVES.
SO...ON MONDAY...CLOUDS THICKEN...AND SCATTERED SHOWERS GRADUALLY
BUILD EAST. LIGHT SOUTH TO SOUTHEAST WINDS SHOULD NOT HELP MIXING
MUCH. SO HIGHS MAINLY IN THE 60S. SCATTERED SHOWERS CONTINUE TO
GRADUALLY SPREAD EAST MONDAY NIGHT...BUT HOW FAR EAST IS THE
QUESTION. EVEN AREAS THAT DO NOT SEE SHOWERS SHOULD SEE A MOSTLY
CLOUDY TO CLOUDY SKY. LOWS SHOULD BE IN THE MID TO UPPER
40S...SOME LOWER 40S SOUTHERN ADIRONDACKS.
TUESDAY INTO WEDNESDAY IS PERIOD OF VERY LOW CONFIDENCE. ONE SET
OF GUIDANCE HAS HIGH PRESSURE STRENGTHENING OVER SOUTHEASTERN
CANADA AND EASTERN NEW ENGLAND...PUSHING CLEARING AND DRYING WEST
INTO OUR REGION. OTHER SETS OF GUIDANCE HAVE LINGERING CLOUDS AND
A SLOWER MORE GRADUAL STRENGTHENING OF THE HIGH PRESSURE TO THE
EAST AND MORE GRADUAL BUILDING WEST OF THE DRYER AIRMASS. THE
CURRENT CLOUD AND MOISTURE FIELD ASSOCIATED WITH THE SYSTEM IS
QUITE EXTENSIVE...SO IT WOULD SEEM THAT IT WOULD TAKE QUITE A BIT
OF TIME FOR THE ATMOSPHERE TO MIX OUT ALL THAT MOISTURE AS THE
UPPER DISTURBANCE WEAKENS...EVEN WE EXPERIENCE LESS RAIN AND
MOSTLY MID AND HIGH LEVEL CLOUDINESS.
AT THIS TIME...SIDING WITH THE LINGERING MOISTURE AND CLOUDS AND
THE SLOWER DEVELOPMENT OF THE RIDGING...WHICH WOULD LIMIT THE
SUNSHINE TO SOME DEGREE...AND RESULT IN TEMPERATURES ON THE
COOLER SIDE OF GUIDANCE TUESDAY AND LOW TEMPERATURES ON THE WARMER
SIDE OF GUIDANCE TUESDAY NIGHT. COOLER BOUNDARY LAYER TEMPERATURES
ARE FORECASTED BUILD WEST AS THE RIDGING STRENGTHENS TO THE
EAST...SO EVEN IF WE END UP HAVING MORE CLEARING IN EASTERN NY AND
WESTERN NEW ENGLAND...THE WARMING COULD BE LIMITED DUE TO THE
COOLER BOUNDARY LAYER TEMPERATURES. ALSO...WITH SOUTH TO SOUTHEAST
LOW LEVEL FLOW...THERE COULD BE SOME LINGERING MARINE LAYER TYPE
CLOUDS...BUT AGAIN...TOO FAR OUT TO HAVE HIGH CONFIDENCE. ALL
GUIDANCE SUGGESTS THERE SHOULD BE DECREASING COVERAGE OF SHOWERS
LATER MONDAY NIGHT THROUGH TUESDAY NIGHT...ALSO GETTING CONFINED
MORE WESTWARD WITH TIME AS THE UPPER RIDGING DOES BUILD WEST FROM
NEW ENGLAND AND CANADA.
HIGHS TUESDAY IN THE 60S WITH LOWS TUESDAY NIGHT IN THE 40S...SOME
30S IN THE SOUTHERN ADIRONDACKS...AND PARTS OF THE SOUTHERN GREEN
MOUNTAINS AND BERKSHIRES.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
HIGH PRESSURE WILL REMAIN IN CONTROL THROUGH MOST OF THIS PERIOD.
THIS SHOULD KEEP OUR REGION GENERALLY FAIR...WITH JUST SOME
OCCASIONAL CLOUDINESS...ESP ACROSS SOUTHERN AREAS WHERE SOME
PERIODIC MARINE INFLUENCE/MOISTURE MAY REACH. TEMPERATURES SHOULD
REMAIN ABOVE SEASONAL LEVELS...WITH MAX TEMPS REACHING 70-75 IN
VALLEY AREAS...WARMEST ACROSS THE WESTERN MOHAWK VALLEY AND UPPER
HUDSON VALLEY WHICH WILL HAVE THE LEAST OF ANY POTENTIAL MARINE
INFLUENCE AND COOLING...AND GENERALLY 65-70 ACROSS HIGHER
ELEVATIONS. OVERNIGHT MINS SHOULD FALL INTO THE LOWER 40S WITHIN
MOST VALLEY LOCALES...AND 30S ACROSS HIGHER ELEVATIONS.
THERE IS SOME POSSIBILITY OF A WEAK BACKDOOR COLD FRONT TO SETTLING
SOUTH/WEST ACROSS THE REGION DURING FRIDAY...WHICH THE 12Z/28 ECMWF
HINTS AT BEST. THIS COULD CREATE A BIT MORE CLOUDINESS AT SOME POINT
ON FRIDAY...AND PERHAPS AN ISOLATED SHOWER OR TWO. HOWEVER...AT THIS
TIME RANGE...IT APPEARS TO BE A LOW ENOUGH PROBABILITY TO KEEP OUT
ANY MENTION IN ONGOING FORECAST.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
HIGH PRESSURE WILL SETTLE ALONG THE NEW ENGLAND COAST TONIGHT INTO
MONDAY...AS A WEAKENING UPPER LEVEL DISTURBANCE APPROACHES FROM THE
OHIO VALLEY AND MID ATLANTIC REGION. THIS WILL RESULT IN GRADUALLY
INCREASING CLOUDS WITH LOWERING CIGS THROUGH THE PERIOD ENDING AT
06Z TUESDAY. DESPITE THE APPROACH OF THE UPPER LEVEL DISTURBANCE...
EXPECT MAINLY VFR CONDITIONS AT THE KGFL/KALB/KPOU/KPSF TAF SITES
THROUGH 06Z TUESDAY AS MODELS INDICATE LITTLE IF ANY PCPN WILL REACH
THE TAF SITES. WHERE THE THREAT OF ISOALTED TO SCT SHOWERS EXIST...
HAVE INCLUDED VCSH IN THE FORECAST.
WINDS WILL BE SOUTH TO SOUTHEAST AT 10 KT OR LESS THORUGH A FEW
HOURS AFTER SUNRISE AT KGFL/KALB...BUT THERE COULD STILL BE A FEW
GUSTS UP TO AROUND 15 KTS. AT KPSF/KPOU EXPECT LIGHT WINDS DURING
THIS PERIOD. LATER MONDAY MORNING THE SOUTH TO SOUTHEAST WINDS WILL
INCREASE AGAIN TO 8 TO 12 KTS WITH SOME GUSTS TO 15 TO 18 KTS...
ESPECIALLY AT KALB. AFTER SUNSET WITH WINDS WILL BECOME LIGHT ONCE
AGAIN...EXCEPT REMAIN SOUTH AT AROUND 10 KTS AT KALB.
OUTLOOK...
LATE MON NT...MAINLY VFR. CHC -SHRA AND ASSOC MVFR.
TUE-TUE NT...MAINLY VFR. SLIGHT CHC -SHRA AND POSS STRATUS WITH MVFR.
WED-FRI...VFR. NO SIG WX.
&&
.FIRE WEATHER...
SURFACE HIGH PRESSURE WILL DOMINATE THE WEATHER ACROSS THE NORTHEAST
UNTIL IT MOVES EAST OFF NEW ENGLAND TOMORROW. THE NEXT THREAT
OF RAIN IS LATE TOMORROW INTO TUESDAY AS A WEAK UPPER LEVEL
DISTURBANCE TRACKS THROUGH THE REGION.
RH VALUES WILL INCREASE TO THE 75 TO 100 PERCENT RANGE
TONIGHT...THEN DROP TO DROP TO MAINLY THE 35 TO 45 PERCENT RANGE
TOMORROW AFTERNOON. RH VALUES WILL INCREASE TO THE 75 TO 100
PERCENT RANGE TOMORROW NIGHT...THEN DROP TO DROP TO MAINLY THE 35
TO 45 PERCENT RANGE TUESDAY.
WINDS SHOULD BE SOUTH TO SOUTHEAST AT LESS THAN 15 MPH
TONIGHT...THEN INCREASE TO AROUND 15 MPH TOMORROW...DROPPING BELOW
15 MPH AGAIN TOMORROW NIGHT...AND AROUND 15 MPH TUESDAY.
SHOWERS SHOULD ONLY BE SCATTERED TOMORROW THROUGH TUESDAY...WITH
THE BEST COVERAGE WEST OF THE HUDSON VALLEY. RAINFALL AMOUNTS
SHOULD BE LESS THAN A QUARTER INCH THROUGH THE PERIOD.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE EXPECTED IN THE ALY HYDRO SERVICE AREA THE
NEXT 5 DAYS. RAINFALL WITH THE NEXT SYSTEM LATE TOMORROW INTO
TUESDAY...LOOKS TO BE A QUARTER INCH OR LESS WHICH WOULD RESULT
IN NO SIGNIFICANT RISES ON ANY WATERSHEDS.
DRY WEATHER LOOKS TO RETURN LATER TUESDAY INTO MUCH OF THE REMAINDER
OF WEEK.
THE SPOTTY SNOWPACK IN THE SOUTHERN ADIRONDACKS AND SOUTHERN GREENS
IS NOT EXPECTED TO CAUSE ANY HYDRO CONCERNS. OVERALL...FLOWS WILL
CONTINUE TO LOWER IN THE PREDOMINANTLY DRY REGIME THE NEXT SEVERAL
DAYS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...HWJIV
NEAR TERM...HWJIV/KL
SHORT TERM...NAS
LONG TERM...KL
AVIATION...GJM
FIRE WEATHER...NAS
HYDROLOGY...NAS
AREA FORECAST DISCUSSION
NWS ALBANY NY
1230 AM EDT MON APR 29 2013
.SYNOPSIS...
HIGH PRESSURE HAS RETREATED TO THE EAST. AN BAND OF SHOWERS WAS
ATTEMPTING TO MOVE INTO AREAS WEST OF THE HUDSON. SCATTERED SHOWERS
WILL WORK INTO MOST AREAS ON MONDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1230 PM EDT...WENT AHEAD AND RAISED OVERNIGHT LOW TEMPERATURES
A FULL CATEGORY (3 DEGREES) ACROSS THE BOARD. CLOUDS WERE IN TO
STAY...AND MOST AREAS NOW HAD A BREEZE 5 TO 10 MPH FROM THE
SOUTH...AND IN SOME CASES GUSTING TO OVER 20 MPH. THESE TWO FACTORS
(CLOUDS AND BREEZE) WILL KEEP TEMPERATURES FROM FALLING A WHOLE LOT
MORE OVERNIGHT.
WATCHING A BAND OF SHOWERS NEAR I-81 BUT AS THEY MOVE INTO DRY AIR
HAVE HAD A HARD TIME MOVING EAST. THE EXPERIMENTAL HRRR EARLIER
INDICATED SHOWERS WOULD MOVE INTO THE CAPITAL DISTRICT BY SUNRISE.
HOWEVER...THE LATEST VERSION HAS BACKED OFF THIS ARRIVAL TIME UNTIL
AFTER SUNRISE...WHICH GENERALLY AGREED WITH THE 00Z AND INCOMING 00Z
GFS. FOR NOW...MADE NO CHANGES IN THE POP FIELDS.
SO FOR THE REST OF OVERNIGHT...IT WILL STAY RELATIVELY MILD WITH
LOWS AROUND 50 IN THE GREATER CAPITAL DISTRICT....MID OR UPPER 40S
MOST OTHER PLACES. THE SOUTH BREEZE WILL CONTINUE AND LIGHT
SCATTERED SHOWERS WILL SLOWLY WORK TO THE WEST OF THE HUDSON
BRINGING UNDER A TENTH OF AN INCH OF RAINFALL. IT SHOULD REMAIN DRY
FROM THE HUDSON VALLEY ON EASTWARD ALTHOUGH CLOUDS WILL THICKEN.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY/...
SOME QUITE NOTICEABLE DISCREPANCIES IN SOURCES OF GUIDANCE THROUGH
THE PERIOD...ESPECIALLY IN THE TOMORROW NIGHT THROUGH WEDNESDAY
TIME FRAME. UNTIL THEN...THE WEAKENING UPPER DISTURBANCE IS
EXPECTED TO WASH OUT...WITH THE EASTERN EXTENT OF THE AREA OF
SHOWERS A BIT IN QUESTION. THE BATTLE BETWEEN THE RIDGING OFF
CANADA AND THE ADVANCING MOISTURE IN THE WEAKENING UPPER
DISTURBANCE SHOULD SUPPORT SOME AREA OF SCATTERED SHOWERS ALONG
AND WEST OF THE HUDSON VALLEY...WITH ONLY ISOLATED ACTIVITY EAST
OF THE HUDSON VALLEY INTO WESTERN NEW ENGLAND. SOME PARTS OF
WESTERN NEW ENGLAND MAY NOT SEE ANY RAIN THROUGH WEDNESDAY
DEPENDING ON HOW THE WEAKENING UPPER DISTURBANCE EVOLVES.
SO...ON MONDAY...CLOUDS THICKEN...AND SCATTERED SHOWERS GRADUALLY
BUILD EAST. LIGHT SOUTH TO SOUTHEAST WINDS SHOULD NOT HELP MIXING
MUCH. SO HIGHS MAINLY IN THE 60S. SCATTERED SHOWERS CONTINUE TO
GRADUALLY SPREAD EAST MONDAY NIGHT...BUT HOW FAR EAST IS THE
QUESTION. EVEN AREAS THAT DO NOT SEE SHOWERS SHOULD SEE A MOSTLY
CLOUDY TO CLOUDY SKY. LOWS SHOULD BE IN THE MID TO UPPER
40S...SOME LOWER 40S SOUTHERN ADIRONDACKS.
TUESDAY INTO WEDNESDAY IS PERIOD OF VERY LOW CONFIDENCE. ONE SET
OF GUIDANCE HAS HIGH PRESSURE STRENGTHENING OVER SOUTHEASTERN
CANADA AND EASTERN NEW ENGLAND...PUSHING CLEARING AND DRYING WEST
INTO OUR REGION. OTHER SETS OF GUIDANCE HAVE LINGERING CLOUDS AND
A SLOWER MORE GRADUAL STRENGTHENING OF THE HIGH PRESSURE TO THE
EAST AND MORE GRADUAL BUILDING WEST OF THE DRYER AIRMASS. THE
CURRENT CLOUD AND MOISTURE FIELD ASSOCIATED WITH THE SYSTEM IS
QUITE EXTENSIVE...SO IT WOULD SEEM THAT IT WOULD TAKE QUITE A BIT
OF TIME FOR THE ATMOSPHERE TO MIX OUT ALL THAT MOISTURE AS THE
UPPER DISTURBANCE WEAKENS...EVEN WE EXPERIENCE LESS RAIN AND
MOSTLY MID AND HIGH LEVEL CLOUDINESS.
AT THIS TIME...SIDING WITH THE LINGERING MOISTURE AND CLOUDS AND
THE SLOWER DEVELOPMENT OF THE RIDGING...WHICH WOULD LIMIT THE
SUNSHINE TO SOME DEGREE...AND RESULT IN TEMPERATURES ON THE
COOLER SIDE OF GUIDANCE TUESDAY AND LOW TEMPERATURES ON THE WARMER
SIDE OF GUIDANCE TUESDAY NIGHT. COOLER BOUNDARY LAYER TEMPERATURES
ARE FORECASTED BUILD WEST AS THE RIDGING STRENGTHENS TO THE
EAST...SO EVEN IF WE END UP HAVING MORE CLEARING IN EASTERN NY AND
WESTERN NEW ENGLAND...THE WARMING COULD BE LIMITED DUE TO THE
COOLER BOUNDARY LAYER TEMPERATURES. ALSO...WITH SOUTH TO SOUTHEAST
LOW LEVEL FLOW...THERE COULD BE SOME LINGERING MARINE LAYER TYPE
CLOUDS...BUT AGAIN...TOO FAR OUT TO HAVE HIGH CONFIDENCE. ALL
GUIDANCE SUGGESTS THERE SHOULD BE DECREASING COVERAGE OF SHOWERS
LATER MONDAY NIGHT THROUGH TUESDAY NIGHT...ALSO GETTING CONFINED
MORE WESTWARD WITH TIME AS THE UPPER RIDGING DOES BUILD WEST FROM
NEW ENGLAND AND CANADA.
HIGHS TUESDAY IN THE 60S WITH LOWS TUESDAY NIGHT IN THE 40S...SOME
30S IN THE SOUTHERN ADIRONDACKS...AND PARTS OF THE SOUTHERN GREEN
MOUNTAINS AND BERKSHIRES.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
HIGH PRESSURE WILL REMAIN IN CONTROL THROUGH MOST OF THIS PERIOD.
THIS SHOULD KEEP OUR REGION GENERALLY FAIR...WITH JUST SOME
OCCASIONAL CLOUDINESS...ESP ACROSS SOUTHERN AREAS WHERE SOME
PERIODIC MARINE INFLUENCE/MOISTURE MAY REACH. TEMPERATURES SHOULD
REMAIN ABOVE SEASONAL LEVELS...WITH MAX TEMPS REACHING 70-75 IN
VALLEY AREAS...WARMEST ACROSS THE WESTERN MOHAWK VALLEY AND UPPER
HUDSON VALLEY WHICH WILL HAVE THE LEAST OF ANY POTENTIAL MARINE
INFLUENCE AND COOLING...AND GENERALLY 65-70 ACROSS HIGHER
ELEVATIONS. OVERNIGHT MINS SHOULD FALL INTO THE LOWER 40S WITHIN
MOST VALLEY LOCALES...AND 30S ACROSS HIGHER ELEVATIONS.
THERE IS SOME POSSIBILITY OF A WEAK BACKDOOR COLD FRONT TO SETTLING
SOUTH/WEST ACROSS THE REGION DURING FRIDAY...WHICH THE 12Z/28 ECMWF
HINTS AT BEST. THIS COULD CREATE A BIT MORE CLOUDINESS AT SOME POINT
ON FRIDAY...AND PERHAPS AN ISOLATED SHOWER OR TWO. HOWEVER...AT THIS
TIME RANGE...IT APPEARS TO BE A LOW ENOUGH PROBABILITY TO KEEP OUT
ANY MENTION IN ONGOING FORECAST.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
HIGH PRESSURE WILL SETTLE ALONG THE NEW ENGLAND COAST TONIGHT INTO
MONDAY...AS A WEAKENING UPPER LEVEL DISTURBANCE APPROACHES FROM THE
OHIO VALLEY AND MID ATLANTIC REGION. THIS WILL RESULT IN GRADUALLY
INCREASING CLOUDS WITH LOWERING CIGS THROUGH THE PERIOD STARTING
THIS EVENING. STILL...CIGS EXPECTED TO REMAIN IN VFR RANGE THROUGH
MOST OF THE 24 HOUR PERIOD ENDING 00Z TUESDAY. WILL INTRODUCE VCSH
AT KPOU AND KALB BETWEEN 08Z-11Z MONDAY ASSOCIATED WITH THE
DISTURBANCE MOVING THROUGH...AND 12Z-14Z AT KGFL AND KPSF...AS
ISOLATED TO SCATTERED...LIGHT RAIN SHOWERS DEVELOP...AND MAY PERSIST
THROUGH MONDAY AFTERNOON.
WINDS WILL BE SOUTH TO SOUTHEAST AT 5-10 KT TONIGHT...AND 8-12 KT BY
MONDAY AFTERNOON. SOME SLIGHTLY STRONGER WINDS WILL BE POSSIBLE AT
KALB DUE TO ENHANCED CHANNELED FLOW WITHIN THE HUDSON RIVER
VALLEY...WITH SOME GUSTS POSSIBLY REACHING AROUND OR OVER 20 KT AT
TIMES TONIGHT THROUGH MONDAY AFTERNOON.
OUTLOOK...
MON NT...MAINLY VFR. CHC -SHRA AND ASSOC MVFR.
TUE-TUE NT...MAINLY VFR. SLIGHT CHC -SHRA AND POSS STRATUS WITH MVFR.
WED-FRI...VFR. NO SIG WX.
&&
.FIRE WEATHER...
SURFACE HIGH PRESSURE WILL DOMINATE THE WEATHER ACROSS THE NORTHEAST
UNTIL IT MOVES EAST OFF NEW ENGLAND TOMORROW. THE NEXT THREAT
OF RAIN IS LATE TOMORROW INTO TUESDAY AS A WEAK UPPER LEVEL
DISTURBANCE TRACKS THROUGH THE REGION.
RH VALUES WILL INCREASE TO THE 75 TO 100 PERCENT RANGE
TONIGHT...THEN DROP TO DROP TO MAINLY THE 35 TO 45 PERCENT RANGE
TOMORROW AFTERNOON. RH VALUES WILL INCREASE TO THE 75 TO 100
PERCENT RANGE TOMORROW NIGHT...THEN DROP TO DROP TO MAINLY THE 35
TO 45 PERCENT RANGE TUESDAY.
WINDS SHOULD BE SOUTH TO SOUTHEAST AT LESS THAN 15 MPH
TONIGHT...THEN INCREASE TO AROUND 15 MPH TOMORROW...DROPPING BELOW
15 MPH AGAIN TOMORROW NIGHT...AND AROUND 15 MPH TUESDAY.
SHOWERS SHOULD ONLY BE SCATTERED TOMORROW THROUGH TUESDAY...WITH
THE BEST COVERAGE WEST OF THE HUDSON VALLEY. RAINFALL AMOUNTS
SHOULD BE LESS THAN A QUARTER INCH THROUGH THE PERIOD.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE EXPECTED IN THE ALY HYDRO SERVICE AREA THE
NEXT 5 DAYS. RAINFALL WITH THE NEXT SYSTEM LATE TOMORROW INTO
TUESDAY...LOOKS TO BE A QUARTER INCH OR LESS WHICH WOULD RESULT
IN NO SIGNIFICANT RISES ON ANY WATERSHEDS.
DRY WEATHER LOOKS TO RETURN LATER TUESDAY INTO MUCH OF THE REMAINDER
OF WEEK.
THE SPOTTY SNOWPACK IN THE SOUTHERN ADIRONDACKS AND SOUTHERN GREENS
IS NOT EXPECTED TO CAUSE ANY HYDRO CONCERNS. OVERALL...FLOWS WILL
CONTINUE TO LOWER IN THE PREDOMINANTLY DRY REGIME THE NEXT SEVERAL
DAYS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...HWJIV
NEAR TERM...HWJIV/KL
SHORT TERM...NAS
LONG TERM...KL
AVIATION...KL/JPV
FIRE WEATHER...NAS
HYDROLOGY...NAS
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
915 PM EDT TUE APR 30 2013
.DISCUSSION...
CURRENT-OVERNIGHT...ANOTHER ROUND OF STRONG STORMS ACROSS EAST
CENTRAL FLORIDA THIS EVENING. CURRENT ACTIVITY IS WINDING DOWN AND
EXPECT THIS TREND TO CONTINUE THROUGH LATE EVENING. WILL UPDATE
ZONES SHORTLY BUT STILL HANG ONTO A SMALL THREAT FOR SHOWERS
OVERNIGHT...THOUGH SUSPECT MOST PLACES WILL REMAIN DRY AFTER CURRENT
SHRA/TSRA DISSIPATE. INCREASING MID/UPR LVL CLOUD DECK WILL COUPLE
WITH LIGHT ONSHORE BREEZE TO KEEP MIN TEMPS IN THE M/U60S.
WEDNESDAY...PREVIOUS...SCT/NMRS SHRAS AND TSRAS TO CONTINUE AS MUCH
OF THE GOMEX/SW ATLC REMAINS UNDER THE INFLUENCE OF THE SHORT WAVE
TROF OFF THE CAROLINA COAST AND THE SHORT WAVE TROF OVER THE NW
GOMEX. A WEAK SFC FRONT ASSOCD WITH THE TROF WILL STALL ACRS CENTRAL
FL...KEEPING THE PENINSULA UNDER A DEEP MOISTURE BAND WITH PWATS
BTWN 1.6"-1.7". RUC ANALYSIS SUGGESTS THE REGION WILL REMAIN COLD
ALOFT WITH H50 TEMPS HOLDING ARND -11C...WHILE THE SRN BRANCH OF THE
H30-H20 JET STREAM OVER THE SOUTHERN GOMEX/GREATER ANTILLES WILL
KEEP THE FL PENINSULA UNDER MODERATE TO STRONG UPR LVL DIVERGENCE.
W/NW FLOW ABV H70 BTWN 10-15KTS...DECREASING TO BLO 10KTS THRU THE
H100-H70 LYR. THIS WILL LIMIT THE POTENTIAL FOR BLOW BACK PRECIP
ALONG THE COAST...WILL FOCUS HIGHEST POPS OVER THE INTERIOR. DENSE
CLOUD COVER AND RAIN COOLED AIR WILL KEEP MAX TEMPS AOB CLIMO...
GENERALLY L80S ALONG THE COAST AND M80S INTERIOR.
&&
.AVIATION...TIL 01/14Z...PREVAILING VFR WITH CIGS BECOMING AOA
FL120...LCL MVFR CIGS/VSBYS IN BR AND LOW STRATUS S OF KISM-KMLB
LATE OVERNIGHT AND TOWARDS SUNRISE. AFT 14Z...SFC WNDS BCMG NE BTWN
10-15KTS. ANOTHER ROUND OF SHRA/TSRA ON TAP FOR WED
AFTERNOON/EVENING.
&&
.MARINE...OVERNIGHT...ENE/E WINDS MAINLY AOB 10 KTS. A PERSISTENT
LONG PD SWELL WILL MAINTAIN 3-4 FT SEAS NEAR SHORE...4-5 FT SEAS
OFFSHORE. ONLY AN ISOLD THREAT FOR A SHOWER/STORM THE REMAINDER OF
THE NIGHT.
WEDNESDAY...PREVIOUS...WINDS WILL GRADUALLY FRESHEN OUT OF THE NE AS
A HIGH PRES RIDGE OVER THE NEW ENGLAND/MID ATLC COAST BEGINS TO NOSE
ITS WAY DOWN THE ERN SEABOARD. WINDS 10-15KTS N OF SEBASTIAN
INLET...AOB 10KTS TO THE S. LITTLE CHANGE IN SEAS AS THE INCREASING
SFC/BNDRY LYR WINDS WILL NOT BE IN PLACE LONG ENOUGH TO GENERATE LCL
WIND WAVES ON TOP OF THE 4-5FT LONG PD SWELL.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SEDLOCK
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
330 AM EDT MON APR 29 2013
.DISCUSSION...
...HIGHER STORM COVERAGE LATER TODAY WITH STRONG STORMS POSSIBLE...
...INCREASINGLY LONG PERIOD SWELL BRINGS HIGH RIP CURRENT THREAT...
CURRENT...AXIS OF MERIDIONAL ATLC HIGH PRESSURE RIDGE LIES ROUGHLY
ALONG 70W...WITH LOW TO MID LEVEL SE-SRLY FLOW IN PLACE OVER THE FL
PENINSULA. WATER VAPOR IMAGERY AND RUC ANLYS FIELDS SHOW POSITIVE
TILT MID-UPPER TROUGH EXTENDING FROM THE CTRL GULF COAST THRU THE
TN VALLEY. JUST AHEAD OF THIS FEATURE THERE APPEARS TO BE A WEAK
VORT INVOF MOBILE BAY. FAIRLY HEALTHY SWATH OF UPPER LEVEL RH AND
DIVG CAN BE SEEN IN THE RUC ANLYS FIELDS TO THE W-NW-N OF FL. SOME
SPOTTY SMALL NWD MOVING SHOWERS NOTED ON LOCAL 88D RADARS STRADDLING
THE PENINSULA OVER BOTH THE GOMEX AND ADJACENT ATLC. SKIES PRETTY
MUCH CLOUD FREE OVER LAND FOR NOW...HOWEVER SOME THICKER CI/CS IS
JUST ABOUT TO MOVE OVHD.
TODAY/TONIGHT...LOCAL AIR MASS WILL TRANSITION TO ONE MUCH MORE
CONDUCIVE FOR PRODUCING PRECIP OVER THE NEXT H12-18 AS DEEPENING
S-SW FLOW DRAWS HIGHER PWAT AIR NORTH AND NEWD ACROSS THE STATE
WHILE INCREASING UPR DIVG WILL AID ASCENT/DEVELOPMENT OF DIURNAL
CONVECTION ALONG/AHEAD OF LOCAL SEA BREEZE BOUNDARIES. THINK MOST
OF THE ACTIVITY WILL TAKE PLACE IN THE 6HR TIME FRAME BETWEEN 4PM
AND 10PM OWING...AS DEEP LAYER MOISTURE WILL HOLD OFF UNTIL AFTER
18Z...WITH PEAK HEATING AND BOUNDARY INTERACTIONS COINCIDING A FEW
HOURS LATER. WENT WITH A 40 POP FOR THIS AFTN ALONG THE SPACE AND
TREASURE COASTS NUDGED POPS UP TO 50 INLAND/VOLUSIA AND 60 AROUND
LAKE OKEECHOBEE OWING TO EXPECTED LAKE ENHANCEMENT TO PRECIP.
KEPT A HEALTHY RAIN CHANCE (50-60) IN FOR MID-LATE AS CONTINUED
FORCED ASCENT COUPLED WITH SUFFICIENTLY DEEP MOISTURE AND NUMEROUS
RESIDUAL OUTFLOW BOUNDARY INTERACTIONS SHOULD KEEP SHOWERS/STORMS
GOING AS THE SWRLY STEERING FLOW CARRIES ACTIVITY BACK TOWARD THE
EAST COAST AND INTO THE ATLC.
PER SWODY1...THERE IS SOME CONCERN FOR SOME STRONG TO MARGINALLY
SEVERE STORMS CENTERED AROUND THE LATE AFTERNOON-SUNSET TIME
FRAME AS TEMPS ALOFT ARE FAIRLY COLD (-12C TO -13C) WHEREAS -10C
IS GENERALLY A RULE OF THUMB VALUE FOR STRONG STORMS. PLAN TO HIT
THE THREATS FOR STRONG WINDS/HAIL IN THE HWO/G-HWO SUITE.
TUE-WED...THE SOUTHERN END OF THE SHORTWAVE MOVING INTO THE EASTERN
US EARLY THIS WEEK WILL CONTINUE ACROSS THE SOUTHEAST TUES AND WED
BEFORE BEING ABSORBED IN THE DEEP TROUGH OVER THE ATLANTIC. THE
ASSOCIATED SURFACE FRONT AND WEAK LOW WILL RUN INTO THE LARGE AREA
OF HIGH PRESSURE JUST OFFSHORE THE EASTERN US AND STALL
OUT...LEAVING WEAK TROUGH ACROSS THE FL PENINSULA THROUGH THE
PERIOD.
THE SMALL DIFFERENCES THAT REMAIN BETWEEN GFS AND ECMWF WITH THE
PLACEMENT OF THE TROUGH/SFC LOW WILL AFFECT WHERE THE HIGHEST RAIN
CHANCES END UP FOR BOTH DAYS. HOWEVER...WITH PLENTIFUL DEEP
MOISTURE...500 MB TEMPS REMAINING AROUND -12C TO -14C...AND THE
SOUTHERN BRANCH OF THE JET STREAM OVER THE SRN GOMEX/GREATER
ANTILLES AT 80-90KTS...EXPECT RAIN CHANCES EVERYWHERE TO REMAIN WELL
ABOVE CLIMO FOR THIS TIME OF YEAR AT 40-60 PERCENT. TUES LOOKS TO BE
THE WETTER OF THE TWO DAYS WITH STEERING FLOW OUT OF THE
WEST...GAINING MORE OF AN EASTERLY COMPONENT ON WED.
MAX TEMPS NEAR AVERAGE...LOW-MID 80S ALONG THE COAST...MID 80S
INLAND. MIN TEMPS SLIGHTLY ABOVE AVERAGE IN THE MID TO UPPER 60S.
THU-SUN...BOTH MODELS SHOW AN OMEGA BLOCK EVOLVING ACROSS THE
CENTRAL-EASTERN US AND WESTERN ATLANTIC BY LATE WEEK...THE
DISAGREEMENT OF COURSE REMAINS IN THE DETAILS.
THE NE SURFACE HIGH WILL EXPAND SOUTHWARDS ON THURSDAY BRINGING THE
WEAK LOW FROM THE EARLIER FRONT BACK INTO THE FL PENINSULA WHERE IT
WILL MEANDER IN THE VICINITY INTO THE WEEKEND. THE ECMWF KEEPS
SIGNIFICANTLY MORE MOISTURE ACROSS THE REGION THROUGH THE
PERIOD...ALONG WITH A SLIGHTLY DEEPER SURFACE LOW UNDER LOWER UPPER
HEIGHTS. THE RESULT IS A MUCH WETTER FRI-SUN WHERE THE GFS HAS POPS
AT 20-30 PERCENT.
HAVE KEPT THE ONGOING FORECAST AT 30-40 PERCENT RATHER THAN GOING
QUITE AS HIGH AS THE ECMWF AS THE FINAL SOLUTION WILL ULTIMATELY
DEPEND ON WHERE THE TROUGH/SFC LOW SETS UP IN RELATION TO THE COAST.
WITH BRISK ONSHORE FLOW DEVELOPING...THERE WILL BE A POSSIBILITY FOR
A FEW HEAVY COASTAL CONVERGENCE BANDS TO SET UP.
&&
.AVIATION...VFR. WITH ISOLD/TS SHRA POSSIBLE ALONG THE VRB-SUA
CORRIDOR STARTING 18Z...THEN INCREASING COVERAGE/THREAT FOR IFR
CIGS/VSBY IN TS RA/+RA AT ALL SITES FROM 20Z-04Z.
&&
.MARINE...SOLID 4-6FT LONG PERIOD 14-15S SWELL WILL REMAIN IN PLACE
TODAY/TONIGHT. WILL KEEP CAUTIONARY STATEMENT IN PLACE...PRIMARILY
FOR HIGHER SEAS AS WINDS SHOULD BE RIGHT AROUND 15KT. AM STRONGLY
CONTEMPLATING GOING WITH CFW FOR HIGH RIP CURRENT RISK AS LOCAL
CHECKLIST YIELDED VALUES IN THE "VERY HIGH" RANGE...EVEN WITH SE
FLOW CREATING A NWD FLOWING LONGSHORE CURRENT...THE ENERGY CREATED
BY THESE VERY LNG PERIOD WAVES ARE SURE TO CUT NUMEROUS...FREQUENT
CHANNELS/BREACHES IN THE SAND BAR UP AND DOWN THE COAST.
TUE-FRI...SURFACE TROUGH WILL MOVE INTO THE CENTRAL PENINSULA ON
TUES WITH SOUTH-SOUTHWEST WINDS EARLY IN THE DAY BECOMING LIGHT AND
VARIABLE BY THE AFTERNOON THROUGH DAYBREAK WED. HIGH PRESSURE WILL
NOSE DOWN THE E COAST IN ITS WAKE WITH STEADY NE FLOW AROUND 10KTS
THROUGH THURSDAY. THE WINDS LATE IN THE WEEK INTO THE WEEKEND WILL
ULTIMATELY DEPEND ON WHERE THE TROUGH AND A WEAK SURFACE LOW SET
UP...BUT MODELS POINT TO A PERIOD OF MODERATE EAST-NORTHEAST FLOW OF
AT LEAST 10-15KTS.
LONG PERIOD SWELL WILL CONTINUE INTO TUES WITH SEAS 4-6FT AT
13-14SEC...SUBSIDING TO 3-5FT WED NIGHT INTO THU...THEN REBUILDING
TO 5-8FT FRI AS THE GRADIENT INCREASES BETWEEN THE TROUGH AND HIGH
TO THE NORTH.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 83 65 82 65 / 50 60 60 30
MCO 86 65 86 65 / 40 50 60 20
MLB 83 69 83 68 / 40 60 60 30
VRB 83 69 85 66 / 40 60 60 30
LEE 85 65 85 66 / 50 50 50 20
SFB 87 66 87 67 / 50 50 60 20
ORL 86 66 87 68 / 50 50 60 20
FPR 83 69 85 66 / 40 60 60 30
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM/AVIATION...CRISTALDI
LONG TERM/IMPACT WX....MOSES
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
511 PM CDT MON APR 29 2013
.DISCUSSION...
323 PM CDT
MAIN FORECAST CONCERNS ARE TRYING TO TIME PERIODS OF PRECIP
POTENTIAL THROUGH MID-WEEK...AND WARM TEMPS DURING THE SAME TIME
PERIOD. BEYOND MID-WEEK...CLOSED UPPER LOW LOOKS TO INFLUENCE LOCAL
WEATHER FOR SEVERAL DAYS WITH COOLER TEMPS AND PERSISTENT THREAT OF
SCATTERED SHRA/TSRA.
NEAR TERM...TONIGHT-WEDNESDAY
SMALL CLUSTER OF ISOLATED SHRA/TSRA CONTINUES TO PROPAGATE EAST
ALONG THE IL/WI BORDER THIS AFTERNOON...ON NOSE OF 25-30 KT LOW
LEVEL JET PER LOCAL VWP AND ASSOCIATED WARM/MOIST ADVECTION. HAS NOT
BEEN MUCH REDEVELOPMENT UPSTREAM OF THIS CLUSTER...THOUGH IT HAS
BEEN QUITE PERSISTENT IN MAINTAINING AT LEAST ONE FAIRLY STRONG TSRA
CORE FOR SEVERAL HOURS. EXPECT THIS WILL CONTINUE TO MOVE EAST
ACROSS BOONE/MCHENRY AND LAKE COUNTIES OVER THE NEXT COUPLE OF HOURS
AND MAY PRODUCE SOME ISOLATED NICKEL-QUARTER SIZED HAIL SOUTH OF THE
WI STATE LINE. LOOKING AT THE BIGGER PICTURE...GOES VAPOR IMAGERY
DEPICTS ONE MID-LEVEL SHORT WAVE MOVING ACROSS WI/NORTHERN GREAT
LAKES REGION THIS AFTERNOON...WITH ANOTHER UPSTREAM ACROSS KS/NEBR.
IT WOULD APPEAR THAT THERE WOULD BE A LULL IN PRECIP DEVELOPMENT
BETWEEN THESE TWO FORCING MECHANISMS THIS EVENING...WITH THE PLAINS
WAVE APPROACHING THE AREA LATE TONIGHT. HOWEVER...SEVERAL HIGH-RES
CONVECTION-ALLOWING MODELS INDICATE POTENTIAL REDEVELOPMENT OF
SHRA/TSRA ACROSS EASTERN IA INTO NORTHERN IL THIS EVENING...WHERE
WEAK LOW LEVEL JET AND MOIST/INSTABILITY AXIS LINGER. MID-AFTERNOON
VISIBLE SATELLITE IMAGERY DOES INDICATE SOME CU ATTEMPTING TO FORM
ACROSS SOUTHEAST IA WITHIN SFC MOIST AXIS...THOUGH IT IS NOT TOO
IMPRESSIVE AT THIS TIME. SPC RAP MESOANALYSIS DATA DOES DEPICT AN
AXIS OF 1000-2000 J/KG MLCAPE ACROSS SE IA...THOUGH ALSO INDICATES
SOME 75-100 J/KG OF CIN. BASED ON PRESENCE OF MOIST/UNSTABLE AXIS
AND HIGH-RES GUIDANCE TRENDS OF REDEVELOPMENT HAVE CHOSEN TO
MAINTAIN CHANCE POPS FOR SHRA/TSRA ACROSS MAINLY AREAS NORTH OF I-80
THROUGH TONIGHT...ESPECIALLY WEST THIS EVENING AND SPREADING FARTHER
EAST LATER TONIGHT. LACK OF STRONGER SHORT WAVE FORCING KEEPS
CONFIDENCE ON THE LOW SIDE THIS EVENING HOWEVER...WITH A LITTLE
HIGHER CONFIDENCE OVERNIGHT AS PLAINS SHORT WAVE APPROACHES AND
PASSES ACROSS THE AREA EARLY TUESDAY MORNING.
ON TUESDAY...ONCE MORNING SHORT WAVE PASSES IT APPEARS FORCING FOR
ORGANIZED PRECIP WILL BE LACKING. COLD FRONT TO OUR WEST IS NOT
EXPECTED TO MAKE PROGRESS EAST AS UPPER FLOW AMPLIFIES IN RESPONSE
TO STRONG MID/UPPER LEVEL JET MOVING INTO THE PAC NW. THIS
AMPLIFICATION INDUCES SURFACE LOW PRESSURE DEVELOPING AND LIFTING
NORTHEAST INTO ONTARIO. THIS ALLOWS STRONGER LOW LEVEL SOUTH FLOW
ACROSS IL/IN...WITH WARMER TEMPS. COMBINATION OF LOW LEVEL THERMAL
PROGS...850 MB DERIVED TEMP CLIMATOLOGY AND MOS NUMBERS SUGGEST
AFTERNOON HIGHS 80-85...PROVIDED MORNING CLOUD COVER MOVES OUT AS
EXPECTED. 850 MB TEMPS JUST A BIT LOWER WEDNESDAY AS UPPER TROUGH
CONTINUES TO AMPLIFY AND SURFACE COLD FRONTAL TROUGH DRIFTS EAST
INTO THE REGION...THOUGH ESPECIALLY EASTERN AREAS WILL LIKELY BE
BACK INTO THE LOWER 80S WHILE CLOUDS/PRECIP CHANCES INCREASE FROM
THE WEST. VARIOUS GUIDANCE SOLUTIONS SHOW SOME MINOR DIFFERENCES
WITH TIMING OF ARRIVAL OF THE FRONT AND ASSOCIATED PRECIP...THOUGH
ALL BASICALLY INCREASE POPS FAIRLY QUICKLY ACROSS THE CWA WEDNESDAY
NIGHT.
LONGER TERM...THURSDAY-MONDAY
MODELS CONTINUE THE TREND OF THE AMPLIFYING UPPER TROUGH BECOMING
CUT OFF FROM THE MAIN JET AND BECOMING A CLOSED LOW OVER THE
MID/LOWER MISSOURI VALLEY...THEN DRIFTING THIS CIRCULATION TO THE
EAST/NORTHEAST THROUGH THE REMAINDER OF THE FORECAST PERIOD. QUITE A
BIT OF SPREAD REMAINS IN ENSEMBLE SOLUTIONS...AS WELL AS THE
OPERATIONAL RUNS OF THE ECMWF/GFS. HAVE MADE LITTLE CHANGE TO GOING
FORECAST IN THE EXTENDED PERIOD AT THIS POINT BASED ON FAIRLY LOW
CONFIDENCE GIVEN MODEL SPREAD...AND THE NOTORIOUSLY PROBLEMATIC JOB
OF FORECASTING CUT-OFF CLOSED LOW DETAILS DAYS 4 AND BEYOND. OVERALL
HAVE MAINTAINED A FORECAST UTILIZING A BLEND OF GUIDANCE FOR TEMPS
AND POPS. WHILE COOLER...LOOKS LIKE 50S/60S FOR HIGHS AND 40S FOR
LOWS DEPENDING ON CLOUD COVER AND SHOWER COVERAGE. POPS ARE LIKELY
OVERDONE A BIT...AND WILL LIKELY BE ABLE TO BETTER DETAIL THEM IN
COMING DAYS AS THE PATH OF THE UPPER LOW BECOMES MORE CLEAR.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* SHRA/TSRA POSSIBLE OVERNIGHT.
MDB
//DISCUSSION...UPDATED 22Z...
SHRA/TSRA THAT WERE MOVING ALONG THE IL/WI STATE LINE HAVE
DISSIPATED WITH A LITTLE LIGHT RAIN REMAINING NEAR UGN. FOCUS
SHIFTS TO EAST-CENTRAL/NORTHEAST IOWA WHERE NEW DEVELOPMENT IS
POSSIBLE THIS EVENING WHICH WOULD TRACK EASTWARD OVERNIGHT.
ADJUSTED TO TEMPO TSRA MENTION AT RFD AS AM UNABLE TO USE PROB30
IN THE FIRST 9 HRS. WITH POTENTIAL AROUND 40 PERCENT FELT TEMPO
BETTER REFLECTED THE SCENARIO THAN DROPPING MENTION ALTOGETHER.
WILL MAINTAIN PROB30 FOR NOW AT THE REMAINING SITES FOR NOW AND
WILL NEED TO RE-EVALUATE WITH 00Z TAF.
MDB
FROM 18Z...
A FRONT IS NEARLY STATIONARY FROM NORTHERN WISCONSIN THROUGH
CENTRAL IOWA. ONE AREA OF TSRA DEVELOPED NEAR THE FRONT IN IOWA THIS
MORNING AND HAS MOVED INTO WISCONSIN. THERE IS POTENTIAL FOR MORE
TSRA TO DEVELOP NEAR THE FRONT THIS AFTERNOON AS AN UPPER LEVEL
WAVE MOVES THROUGH THE AREA. ANY DEVELOPMENT SHOULD REMAIN TO THE
NORTHWEST OF THE TERMINALS...THOUGH IT COULD GET CLOSE TO RFD AT
SOME POINT. CONFIDENCE IS TOO LOW TO INCLUDE ANY TSRA IN THE RFD
TAF FOR THIS AFTERNOON. THEN THERE IS A SLIGHTLY BETTER CHANCE OF
TSRA AT ALL THE TERMINALS OVERNIGHT WITH ANOTHER WAVE MOVING
ACROSS THE AREA.
SOUTHERLY WINDS...GUSTY IN THE AFTERNOON...AND VFR-LEVEL CLOUDS
WILL CONTINUE AT THE TERMINALS AHEAD OF THE FRONT.
PAW
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* LOW CONFIDENCE IN SHRA/TSRA AT THE TERMINALS...BETTER CHANCE IS
JUST TO THE NORTH. MEDIUM CONFIDENCE IN TIMING OF THE POTENTIAL.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...VFR.
WEDNESDAY...CHC OF TSRA. MVFR POSSIBLE BY NIGHT.
THURSDAY...CHC OF TSRA. MVFR POSSIBLE.
FRIDAY THROUGH SUNDAY...CHC OF SHRA.
BMD
&&
.MARINE...
205 PM CDT
A POTENT AREA OF LOW PRESSURE IS FORECAST MOVE EASTWARD ACROSS THE
DAKOTAS TONIGHT...AND THEN MOVE NORTHEASTWARD ACROSS ONTARIO ON
TUESDAY. STRONG PRESSURE FALLS AND A STRENGTHENING PRESSURE GRADIENT
SHOULD LEAD TO A PERIOD OF STRONGER SOUTHERLY WINDS ACROSS THE LAKE
ON TUESDAY. IT APPEARS WINDS WILL INCREASE TO AROUND 30 KT
LAKE-WIDE.
THIS LOW WILL EVENTUALLY BEGIN TO PUSH A COLD FRONT DOWN LAKE
MICHIGAN DURING THE DAY ON WEDNESDAY. HOWEVER...CONFIDENCE ON THE
TIMING OF THIS FRONT IS A BIT LOW AT THIS TIME..ESPECIALLY ALONG
THE SOUTHERN HALF OF LAKE MICHIGAN. IT APPEARS THE FRONT MAY BE
SLOWED BY THE DEVELOPMENT OF ANOTHER AREA OF LOW PRESSURE ACROSS THE
MID MISSISSIPPI VALLEY. THIS WILL ULTIMATELY AFFECT THE WIND
DIRECTIONS ON SOUTHERN LAKE MICHIGAN LATER THIS WEEK. NORTHERLY
WINDS OF 25 TO 30 KT LOOK TO SET UP FOR A PERIOD IN THE WAKE OF THIS
FRONTAL BOUNDARY ON THURSDAY.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
324 PM CDT MON APR 29 2013
.DISCUSSION...
323 PM CDT
MAIN FORECAST CONCERNS ARE TRYING TO TIME PERIODS OF PRECIP
POTENTIAL THROUGH MID-WEEK...AND WARM TEMPS DURING THE SAME TIME
PERIOD. BEYOND MID-WEEK...CLOSED UPPER LOW LOOKS TO INFLUENCE LOCAL
WEATHER FOR SEVERAL DAYS WITH COOLER TEMPS AND PERSISTENT THREAT OF
SCATTERED SHRA/TSRA.
NEAR TERM...TONIGHT-WEDNESDAY
SMALL CLUSTER OF ISOLATED SHRA/TSRA CONTINUES TO PROPAGATE EAST
ALONG THE IL/WI BORDER THIS AFTERNOON...ON NOSE OF 25-30 KT LOW
LEVEL JET PER LOCAL VWP AND ASSOCIATED WARM/MOIST ADVECTION. HAS NOT
BEEN MUCH REDEVELOPMENT UPSTREAM OF THIS CLUSTER...THOUGH IT HAS
BEEN QUITE PERSISTENT IN MAINTAINING AT LEAST ONE FAIRLY STRONG TSRA
CORE FOR SEVERAL HOURS. EXPECT THIS WILL CONTINUE TO MOVE EAST
ACROSS BOONE/MCHENRY AND LAKE COUNTIES OVER THE NEXT COUPLE OF HOURS
AND MAY PRODUCE SOME ISOLATED NICKEL-QUARTER SIZED HAIL SOUTH OF THE
WI STATE LINE. LOOKING AT THE BIGGER PICTURE...GOES VAPOR IMAGERY
DEPICTS ONE MID-LEVEL SHORT WAVE MOVING ACROSS WI/NORTHERN GREAT
LAKES REGION THIS AFTERNOON...WITH ANOTHER UPSTREAM ACROSS KS/NEBR.
IT WOULD APPEAR THAT THERE WOULD BE A LULL IN PRECIP DEVELOPMENT
BETWEEN THESE TWO FORCING MECHANISMS THIS EVENING...WITH THE PLAINS
WAVE APPROACHING THE AREA LATE TONIGHT. HOWEVER...SEVERAL HIGH-RES
CONVECTION-ALLOWING MODELS INDICATE POTENTIAL REDEVELOPMENT OF
SHRA/TSRA ACROSS EASTERN IA INTO NORTHERN IL THIS EVENING...WHERE
WEAK LOW LEVEL JET AND MOIST/INSTABILITY AXIS LINGER. MID-AFTERNOON
VISIBLE SATELLITE IMAGERY DOES INDICATE SOME CU ATTEMPTING TO FORM
ACROSS SOUTHEAST IA WITHIN SFC MOIST AXIS...THOUGH IT IS NOT TOO
IMPRESSIVE AT THIS TIME. SPC RAP MESOANALYSIS DATA DOES DEPICT AN
AXIS OF 1000-2000 J/KG MLCAPE ACROSS SE IA...THOUGH ALSO INDICATES
SOME 75-100 J/KG OF CIN. BASED ON PRESENCE OF MOIST/UNSTABLE AXIS
AND HIGH-RES GUIDANCE TRENDS OF REDEVELOPMENT HAVE CHOSEN TO
MAINTAIN CHANCE POPS FOR SHRA/TSRA ACROSS MAINLY AREAS NORTH OF I-80
THROUGH TONIGHT...ESPECIALLY WEST THIS EVENING AND SPREADING FARTHER
EAST LATER TONIGHT. LACK OF STRONGER SHORT WAVE FORCING KEEPS
CONFIDENCE ON THE LOW SIDE THIS EVENING HOWEVER...WITH A LITTLE
HIGHER CONFIDENCE OVERNIGHT AS PLAINS SHORT WAVE APPROACHES AND
PASSES ACROSS THE AREA EARLY TUESDAY MORNING.
ON TUESDAY...ONCE MORNING SHORT WAVE PASSES IT APPEARS FORCING FOR
ORGANIZED PRECIP WILL BE LACKING. COLD FRONT TO OUR WEST IS NOT
EXPECTED TO MAKE PROGRESS EAST AS UPPER FLOW AMPLIFIES IN RESPONSE
TO STRONG MID/UPPER LEVEL JET MOVING INTO THE PAC NW. THIS
AMPLIFICATION INDUCES SURFACE LOW PRESSURE DEVELOPING AND LIFTING
NORTHEAST INTO ONTARIO. THIS ALLOWS STRONGER LOW LEVEL SOUTH FLOW
ACROSS IL/IN...WITH WARMER TEMPS. COMBINATION OF LOW LEVEL THERMAL
PROGS...850 MB DERIVED TEMP CLIMATOLOGY AND MOS NUMBERS SUGGEST
AFTERNOON HIGHS 80-85...PROVIDED MORNING CLOUD COVER MOVES OUT AS
EXPECTED. 850 MB TEMPS JUST A BIT LOWER WEDNESDAY AS UPPER TROUGH
CONTINUES TO AMPLIFY AND SURFACE COLD FRONTAL TROUGH DRIFTS EAST
INTO THE REGION...THOUGH ESPECIALLY EASTERN AREAS WILL LIKELY BE
BACK INTO THE LOWER 80S WHILE CLOUDS/PRECIP CHANCES INCREASE FROM
THE WEST. VARIOUS GUIDANCE SOLUTIONS SHOW SOME MINOR DIFFERENCES
WITH TIMING OF ARRIVAL OF THE FRONT AND ASSOCIATED PRECIP...THOUGH
ALL BASICALLY INCREASE POPS FAIRLY QUICKLY ACROSS THE CWA WEDNESDAY
NIGHT.
LONGER TERM...THURSDAY-MONDAY
MODELS CONTINUE THE TREND OF THE AMPLIFYING UPPER TROUGH BECOMING
CUT OFF FROM THE MAIN JET AND BECOMING A CLOSED LOW OVER THE
MID/LOWER MISSOURI VALLEY...THEN DRIFTING THIS CIRCULATION TO THE
EAST/NORTHEAST THROUGH THE REMAINDER OF THE FORECAST PERIOD. QUITE A
BIT OF SPREAD REMAINS IN ENSEMBLE SOLUTIONS...AS WELL AS THE
OPERATIONAL RUNS OF THE ECMWF/GFS. HAVE MADE LITTLE CHANGE TO GOING
FORECAST IN THE EXTENDED PERIOD AT THIS POINT BASED ON FAIRLY LOW
CONFIDENCE GIVEN MODEL SPREAD...AND THE NOTORIOUSLY PROBLEMATIC JOB
OF FORECASTING CUT-OFF CLOSED LOW DETAILS DAYS 4 AND BEYOND. OVERALL
HAVE MAINTAINED A FORECAST UTILIZING A BLEND OF GUIDANCE FOR TEMPS
AND POPS. WHILE COOLER...LOOKS LIKE 50S/60S FOR HIGHS AND 40S FOR
LOWS DEPENDING ON CLOUD COVER AND SHOWER COVERAGE. POPS ARE LIKELY
OVERDONE A BIT...AND WILL LIKELY BE ABLE TO BETTER DETAIL THEM IN
COMING DAYS AS THE PATH OF THE UPPER LOW BECOMES MORE CLEAR.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* SOUTHERLY WINDS...GUSTY THIS AFTERNOON AND AGAIN TUESDAY
AFTERNOON.
* POTENTIAL FOR SHRA/TSRA THIS AFTERNOON AND LATE TONIGHT.
PAW
//DISCUSSION...UPDATED 18Z...
A FRONT IS NEARLY STATIONARY FROM NORTHERN WISCONSIN THROUGH
CENTRAL IOWA. ONE AREA OF TSRA DEVELOPED NEAR THE FRONT IN IOWA THIS
MORNING AND HAS MOVED INTO WISCONSIN. THERE IS POTENTIAL FOR MORE
TSRA TO DEVELOP NEAR THE FRONT THIS AFTERNOON AS AN UPPER LEVEL
WAVE MOVES THROUGH THE AREA. ANY DEVELOPMENT SHOULD REMAIN TO THE
NORTHWEST OF THE TERMINALS...THOUGH IT COULD GET CLOSE TO RFD AT
SOME POINT. CONFIDENCE IS TOO LOW TO INCLUDE ANY TSRA IN THE RFD
TAF FOR THIS AFTERNOON. THEN THERE IS A SLIGHTLY BETTER CHANCE OF
TSRA AT ALL THE TERMINALS OVERNIGHT WITH ANOTHER WAVE MOVING
ACROSS THE AREA.
SOUTHERLY WINDS...GUSTY IN THE AFTERNOON...AND VFR-LEVEL CLOUDS
WILL CONTINUE AT THE TERMINALS AHEAD OF THE FRONT.
PAW
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN WIND TREND.
* LOW CONFIDENCE IN POTENTIAL FOR SHRA/TSRA THIS AFTERNOON AND LATE
TONIGHT.
PAW
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...VFR.
WEDNESDAY...CHC OF TSRA. MVFR POSSIBLE BY NIGHT.
THURSDAY...CHC OF TSRA. MVFR POSSIBLE.
FRIDAY THROUGH SUNDAY...CHC OF SHRA.
BMD
&&
.MARINE...
205 PM CDT
A POTENT AREA OF LOW PRESSURE IS FORECAST MOVE EASTWARD ACROSS THE
DAKOTAS TONIGHT...AND THEN MOVE NORTHEASTWARD ACROSS ONTARIO ON
TUESDAY. STRONG PRESSURE FALLS AND A STRENGTHENING PRESSURE GRADIENT
SHOULD LEAD TO A PERIOD OF STRONGER SOUTHERLY WINDS ACROSS THE LAKE
ON TUESDAY. IT APPEARS WINDS WILL INCREASE TO AROUND 30 KT
LAKE-WIDE.
THIS LOW WILL EVENTUALLY BEGIN TO PUSH A COLD FRONT DOWN LAKE
MICHIGAN DURING THE DAY ON WEDNESDAY. HOWEVER...CONFIDENCE ON THE
TIMING OF THIS FRONT IS A BIT LOW AT THIS TIME..ESPECIALLY ALONG
THE SOUTHERN HALF OF LAKE MICHIGAN. IT APPEARS THE FRONT MAY BE
SLOWED BY THE DEVELOPMENT OF ANOTHER AREA OF LOW PRESSURE ACROSS THE
MID MISSISSIPPI VALLEY. THIS WILL ULTIMATELY AFFECT THE WIND
DIRECTIONS ON SOUTHERN LAKE MICHIGAN LATER THIS WEEK. NORTHERLY
WINDS OF 25 TO 30 KT LOOK TO SET UP FOR A PERIOD IN THE WAKE OF THIS
FRONTAL BOUNDARY ON THURSDAY.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS DES MOINES IA
342 PM CDT MON APR 29 2013
.SHORT TERM.../TONIGHT /...
ISSUED AT 338 PM CDT MON APR 29 2013
MAIN CONCERN FOR THE OVERNIGHT PERIOD WILL BE THE TIMING AND
LOCATION OF ANY CONVECTION. INSTABILITY HAS BEEN ON THE INCREASE
THIS AFTERNOON WITH SBCAPES OF 1000 TO 2000 J/KG ACROSS MUCH OF THE
CWA...AND EVEN HIGHER VALUES AROUND THE MISSOURI BORDER. THE 850 TO
700 MB CAP LOOKS TO WEAKEN AFTER THE 23-00Z TIME FRAME AS A 925MB
MOISTURE PLUME OVER KANSAS AND MISSOURI WORKS NORTHWARD. EXPECTING
CONVECTIVE INITIATION IN THE VICINITY OF THE ASSOCIATED THETA-E
CONVERGENCE ZONE IN SOUTHWEST IOWA OR SOUTHEAST NEBRASKA...WITH THE
CONVECTION TRACKING EAST AND NORTH DURING THE OVERNIGHT. THIRTY TO
FORTY KNOTS OF 0-6 KM SHEAR AND A 40 TO 60 KT LLJ BUILDING IN FROM
THE SOUTHWEST AFTER 03Z WILL AID IN INTENSIFYING AND MAINTAINING ANY
STORMS THAT DO FORM THIS EVENING. BOTH ELEVATED AND SURFACE BASED
CONVECTION IS POSSIBLE WITH THE MAIN THREAT FROM THESE STORMS BEING
LARGE HAIL AND DAMAGING WIND GUSTS.
MANY HIGH RESOLUTION MODELS HAVE BEEN TRENDING THE CONVECTION
SLIGHTLY NORTH AND WEST TODAY. THIS HAS ALSO BEEN REFLECTED IN THE
UPDATED SPC CONVECTIVE DAY 1 SLIGHT RISK OUTLOOKS. IN
GENERAL...LEANED TOWARDS A COMBINATION OF THE EAST NMM AND ARW WRF
CORES AND THE 16Z HRRR FOR PLACEMENT OF THE HIGHEST POPS AND QPF
AMOUNTS. HEAVY RAINFALL IS POSSIBLE WITH SOME OF THESE STORMS OVER
CENTRAL IOWA WITH PWATS EXCEEDING ONE INCH AND LOW LEVEL MIXING
RATIOS AROUND 13 G/KG.
STATIONARY SURFACE BOUNDARY OVER WEST CENTRAL AND NORTH CENTRAL IOWA
WASHED OUT EARLY THIS AFTERNOON...ALLOWING WINDS TO VEER SOUTHWARD
AND TEMPERATURES TO RISE BACK INTO THE 70S. THESE SOUTHERLY WINDS
WILL INCREASE OVERNIGHT AS THE PRESSURE GRADIENT TIGHTENS IN RESPONSE
TO AN APPROACHING NORTHERN PLAINS COLD FRONT. COMBINED WITH DEW POINTS IN
THE UPPER 50S TO NEAR 60...EXPECT OVERNIGHT LOWS TO ONLY FALL OFF
INTO THE LOW 60S.
.LONG TERM.../TUESDAY THROUGH MONDAY/...
ISSUED AT 338 PM CDT MON APR 29 2013
I EXPECT SOME ONGOING CONVECTION MAINLY ACROSS THE EAST IN THE
MORNING WITH A LULL LATE MORNING. ANOTHER COLD FRONT WILL STRETCH
ACROSS CENTRAL IOWA DURING THE DAY ON TUESDAY AND MAKE SLOW ESE
PROGRESS. FORECAST SOUNDINGS SHOW A PRETTY STOUT CAP IN PLACE BUT
IT QUICKLY ERODES DURING THE MID TO LATE AFTERNOON AND INTO THE
EVENING AND THIS IS WHEN I EXPECT THUNDERSTORMS TO BREAK OUT...AHEAD
OF THE BOUNDARY. LOOKING AT SHEAR...THERE IS SOME THAT EXISTS ALONG
THE BOUNDARY BUT THE BEST SHEAR IS FOUND BEHIND THE BOUNDARY. SOME
STORMS COULD PRODUCE LARGE HAIL AND DAMAGING WIND. DURING TUESDAY
EVENING ADDITIONAL STORMS COULD DEVELOP BEHIND THE FRONT AS WELL
WHERE THE BETTER SHEAR WILL EXIST AND THERE WILL STILL BE SOME
INSTABILITY.
ON WEDNESDAY THE UPPER TROUGH OUT TO THE WEST WILL DIG SOUTH ON THE
LEE SIDE OF THE ROCKIES CREATING QUITE THE TEMPERATURE GRADIENT
ACROSS IOWA. ACROSS THE NORTHWEST HALF TO TWO THIRDS OF THE STATE
HIGHS WILL ONLY BE IN THE 40S AND 50S WHILE ACROSS THE SOUTHEAST
TEMPERATURES WILL BE IN THE 60S TO 70S. THIS TROUGH WILL CONTINUE
TO DIG AS IT PLOWS EAST THROUGH THURSDAY. FORECAST SOUNDINGS ON
THURSDAY SHOW FALLING TEMPERATURES THROUGHOUT THE AFTERNOON HOURS.
IN FACT IT LOOKS LIKE HIGHS WILL LIKELY BE REACHED IN THE MORNING
AND THOSE READINGS WILL ONLY BE IN THE 40S. PRETTY DECENT MOISTURE
TRANSPORT WILL TAKE PLACE DURING THIS TIME AND PRECIPITATION WILL
YIELD SOME PRETTY HIGH QPF VALUES THROUGH THE REMAINDER OF THE
WEEK. FORECAST SOUNDINGS SHOW THAT WE WILL BE COLD ENOUGH FOR AT
MINIMUM A RAIN/SNOW MIX DURING THE DAY ON THURSDAY. IF YOU BELIEVE
THE NAM WE WILL BE COLD ENOUGH FOR ALL SNOW. I HAD A HARD TIME
BUYING INTO THAT SOLUTION COMPLETELY BECAUSE FOR THE PAST FEW DAYS
THE NAM HAD BEEN OVERDOING THE MOISTURE AND THE COOLING. THIS WILL
CERTAINLY BEAR WATCHING BUT I WOULD NOT BE SURPRISED TO SEE SNOW
THURSDAY AFTERNOON AND THURSDAY NIGHT.
BEYOND THIS PERIOD...THE MODELS CONTINUE TO POORLY HANDLE THE
EVOLUTION OF THE CLOSED LOW THAT DEVELOPS OUT OF THE TROUGH. THE
EURO LIFTS THIS CLOSED LOW INTO IOWA OVER THE WEEKEND THEN INTO THE
GREAT LAKES ON MONDAY WHILE THE GFS AND GEM TAKE THE LOW TO THE
SOUTH ACROSS THE SOUTHERN PLAINS. THIS SOLUTION WOULD DRAW DOWN
MUCH COLDER AIR ACROSS THE STATE FOR THE WEEKEND. I TRIED TO LEAN
COOLER BUT BY SUNDAY FORECAST SOUNDINGS SUPPORT HIGHS IN THE 50S. AT
THIS POINT I KEPT 40S NW TO 50S SE ON SATURDAY BUT WE COULD INDEED
SEE TEMPS SOME 5 TO 8 DEGREES COOLER THAT WHAT I HAVE GOING. WE
WILL NEED TO SEE HOW THAT CLOSED LOW EVOLVES AND SHIFTS ACROSS THE
AREA. BEFORE THAT HAPPENS THERE IS JUST TOO MUCH MODEL UNCERTAINTY
TO STATE A PREFERENCE.
&&
.AVIATION...29/18Z
ISSUED AT 1251 PM CDT MON APR 29 2013
WINDS OVER NORTHERN IOWA WILL VEER TO THE SOUTH THIS AFTERNOON AS
A FRONTAL BOUNDARY WEAKENS AND LIFTS NORTHWARD. OTHERWISE LOOK FOR
MOSTLY VFR CONDITIONS OVER THE REGION...WITH SOME MID TO HIGH MVFR
STRATOCU OVER NORTHEAST IOWA. NEXT SYSTEM APPROACHES FROM THE
SOUTH THE EVENING. PLACEMENT AND TIMING OF THE ASSOCIATED SHOWERS
AND THUNDERSTORMS REMAINS SOMEWHAT UNCERTAIN...BUT THE GENERAL
TREND WILL BE FOR THE STORMS TO LIFT FROM SOUTHWEST TO NORTHEAST
DURING THE OVERNIGHT HOURS...CLEARING THE REGION SHORTLY AFTER 12Z.
&&
.HYDROLOGY...
ISSUED AT 338 PM CDT MON APR 29 2013
HE MODERATE TO HEAVY RAINFALL EVENT FORECAST IN THE LONG TERM
PERIOD OF THE FORECAST MAY RESULT IN SIGNIFICANT WITHIN-BANK RISES
ALONG MANY STREAMS AND RIVERS. FLOODING IS ALSO
POSSIBLE...ESPECIALLY ALONG THE SMALLER STREAMS AND IN AREAS THAT
RECEIVE HEAVIER RAINFALL. AT THIS TIME IT IS DIFFICULT TO PINPOINT
SPECIFIC STREAMS OR RIVERS GIVEN THE UNCERTAINTY IN THE RAINFALL
FORECAST. THE FORECAST WILL HAVE TO BE MONITORED FOR POTENTIAL
IMPACTS ON AREA RIVERS.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SKOW
LONG TERM...FAB
AVIATION...SKOW
HYDROLOGY...ZOGG
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
800 PM EDT TUE APR 30 2013
.SYNOPSIS...
DRY AND WARM CONDITIONS CAN BE EXPECTED THROUGH THE WEEK.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
REMOVED POPS FROM RIDGES AND MADE ADJUSTMENT TO CLOUDS. UPDATED
TEMPS TO LATEST RUC NUMBERS.
PREVIOUS FORECAST...
OVERALL A QUIET AFTERNOON/EVENING IS IN STORE FOR MUCH OF THE
AREA. A FEW SHOWERS ASSOCIATED WITH MOISTURE FEED OFF OF THE EAST
COAST COULD MAKE IT OVER OUR EASTERN RIDGES THIS AFTERNOON.
HOWEVER...WITH CHANCES REMAINING PRETTY SMALL...ONLY KEPT THE
SLIGHT CHANCE WORDING THROUGH THE AFTERNOON. FURTHER WEST...NOT
MUCH MORE THAN DIURNAL CU AND SOME HIGH CIRRUS BLOW OFF FROM A
DYING CONVECTIVE SYSTEM OVER MICHIGAN IS EXPECTED.
BUILDING RIDGE SHOULD END SHOWER CHANCES TONIGHT THOUGH CLOUD
COVER COULD REMAIN OVER THE EASTERN ZONES WITH EASTERLY FLOW
CONTINUING. LOW CLOUD DECK SHOULD BEGIN TO MIX OUT WEDNESDAY
MORNING...PROVIDING FOR MOSTLY SUNNY SKIES EVERYWHERE BY
AFTERNOON. WITH PLENTY OF INSOLATION...TEMPERATURES WILL CONTINUE
TO REMAIN ABOVE SEASONAL AVERAGES THROUGH THE PERIOD.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
UPPER LEVEL RIDGE WILL CONTINUE TO BE THE PREDOMINANT PLAYER
THROUGH THE END OF THE WEEK WITH LITTLE MORE THAN SOME DIURNAL CU
EXPECTED. BOTH THE NAM AND THE GFS SUGGEST AN INCREASE IN LOW
LEVEL MOISTURE LATER FRIDAY WHICH COULD PROVIDE FOR A BIT MORE
CLOUD COVER AND LOWER HIGH TEMPERATURES. FOR NOW
THOUGH...MAINTAINED VALUES NEAR MEX/MET VALUES...WHICH IS ABOUT
8-10 DEGREES ABOVE SEASONAL NORMALS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
BLOCKED UPPER LEVEL PATTERN REMAINS THE STORY INTO THE WEEKEND WITH
A CLOSED LOW OVER THE NATIONS MID SECTION AND RIDGING ACROSS THE
OHIO VALLEY. MODELS CONTINUE TO HAVE DIFFERING SOLUTIONS FOR WHEN
AND WHERE CLOSED LOW WILL MOVE FOR THE WEEKEND. SLOWED DOWN TIMING
OF SLIGHT SHOWER CHANCES UNTIL LATER SUNDAY WITH LOW CHANCE POPS
MONDAY INTO TUESDAY USING A BLEND OF MODELS. TEMPERATURES WILL TREND
TO SEASONABLE AVERAGES THROUGH THE PERIOD.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
HIGH PRESSURE WILL PROVIDE GENERALLY CLEAR SKIES AND DRY WEATHER
FOR TONIGHT AND WEDNESDAY. THE EXCEPTION WILL BE KDUJ WHERE MVFR
CIGS WILL HOLD OVERNIGHT AS EASTERLY FLOW CONTINUES ENOUGH LOW
LEVEL MOISTURE FOR STRATUS FORMATION. PATCHY MVFR FOG EARLY
MORNING WEDNESDAY IS POSSIBLE...OTHERWISE VFR WITH LIGHT EAST TO SOUTHEAST
WINDS TO CONTINUE THROUGH WEDNESDAY.
.OUTLOOK.../WEDNESDAY NIGHT THROUGH SUNDAY/...
GENERAL VFR CAN BE ANTICIPATED THROUGH THE WEEKEND.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
224 PM EDT MON APR 29 2013
.SYNOPSIS...
LOW PRESSURE LIFTS NORTHEAST ACROSS THE MID ATLANTIC TODAY AND OFF
THE COAST TONIGHT. LOW PRESSURE LINGERS OFF THE CAROLINA COAST
THROUGH MIDWEEK AS HIGH PRESSURE BUILDS OFF THE NEW ENGLAND COAST.
&&
.NEAR TERM /THROUGH TONIGHT/...
CURRENT RADAR TRENDS SHOWING PRECIP CONTINUING TO MOVE E/NE THIS
MORNING...WITH AREAS WEST OF RIC BEGINNING TO SEE SOME BREAKS IN THE
PRECIP. HAVE UPDATED POPS TO SHOW THIS TREND...BUT HAVE KEPT 30-50
PERCENT CHANCE OF PRECIP IN THE WEST TO ACCOUNT FOR -SHRA
DEVELOPMENT THIS AFTERNOON. OTHERWISE FORECAST LOOKS ON TARGET.
PREVIOUS DISCUSSION...
THE LATEST RUC MAINTAINS THIS STRONG LIFT OVER THE LOCAL AREA
THROUGH 12Z BEFORE SHIFTING IT TOWARD THE EASTERN PORTION OF THE
AREA FROM 12-16Z AS THE JET CORE PULLS NE TOWARD LONG ISLAND AND
THE MID-LEVEL TROUGH AXIS INTRUDES FROM THE WEST. THIS SHOULD
ALLOW STEADY RAIN TO SLOWLY TAPER OFF W OF I-95 THROUGH THE
MORNING. THE MAIN AREA OF ASCENT THEN SHIFTS TO SE PORTIONS BY
AFTERNOON AS A SECONDARY SPEED MAX MOVES OVER CENTRAL VA. A FEW
RUMBLES OF THUNDER ARE POSSIBLE OVER SE PORTIONS GIVEN THAT THIS
FEATURE ARRIVES DURING THE AFTERNOON. HOWEVER...AMBIENT RAIN
COOLED STABLE CONDITIONS WILL LIMIT INSTABILITY (AND LIMIT THE
POTENTIAL OF DEEP CONVECTION) HENCE THUNDER WILL NOT BE INCLUDED
IN THE GRIDS. THE LATEST DATA SUGGESTS THAT QPF COULD REACH 1.5IN
AND POSSIBLY CLOSE TO 2.0IN FOR SOME LOCATIONS BY THIS AFTERNOON
ACROSS S-CENTRAL/SE VA/EASTERN SHORE/NE NC. THIS HAS FURTHER
SUPPORT FROM UPSTREAM OBS OVER CENTRAL NC WHERE AMOUNTS HAVE
REACHED 1.0-1.5IN AND RAIN CONTINUES.
THE MID-LEVEL TROUGH AXIS MOVES OFF THE COAST TONIGHT WITH THE
ASSOCIATED WIND FLOW BECOMING NW (ALBEIT WEAK). THIS SHOULD ALLOW
STEADY RAIN TO TAPER OFF TO SHOWERS THIS EVENING FOR EASTERN AREAS.
THERE IS AN ABUNDANT AMOUNT OF LINGERING LOW-LEVEL MOISTURE THAT
WILL NOT BE SCOURED OUT BY WEAK FLOW...SO WIDESPREAD STRATUS IS
EXPECTED TO DEVELOP. THIS COULD EVENTUALLY SETTLE TO THE SURFACE
RESULTING IN THE POTENTIAL FOR FOG.
CLOUD COVER AND RAIN WILL LIMIT HIGH TEMPERATURES TODAY...WITH
READINGS RANGING FROM THE LOW/MID 60S (UPPER 50S ALONG THE ATLANTIC
COAST) OVER THE EASTERN SHORE TO THE UPPER 60S/NEAR 70 S. LOWS
TONIGHT WILL BE MILD AND LARGELY BE IN THE MID 50S.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
HIGH PRESSURE RE-EXERTS ITSELF OVER THE CANADIAN MARITIMES TUESDAY
AND WEDNESDAY AND NUDGES SW ALONG THE NEW ENGLAND COAST.
MEANWHILE...A COASTAL TROUGH LINGERS OFF THE CAROLINA COAST. THIS
WILL MAINTAIN ONSHORE FLOW AND PERSISTENT MOSTLY CLOUDY TO OVERCAST
CONDITIONS. THE LATEST GFS/NAM/ECMWF DRAW MOISTURE AROUND THE
NORTHERN PERIPHERY OF THE TROUGH LATE TUESDAY NIGHT INTO WEDNESDAY
AHEAD OF A BACKDOOR FRONT. HOWEVER...CONFIDENCE IS LOW REGARDING
RAIN POTENTIAL AT THIS TIME...SO WILL GO WITH NO HIGHER THAN A 40
POP. THUNDER POTENTIAL SHOULD REMAIN VERY LIMITED DUE TO ONSHORE
FLOW AND SSTS IN THE LOW/MID 50S. IF ANY THUNDER WERE TO OCCUR
(MAINLY TUE) IT WOULD BE OVER INTERIOR NE NC AND S-CENTRAL VA.
AS FOR TEMPERATURES...THE COOLER MAV GUIDANCE HAS BEEN FOLLOWED AS
MET NUMBERS APPEAR TOO WARM BASED ON EXPECTED CLOUD COVER. THIS
RESULTS IN HIGHS TUESDAY RANGING FROM THE LOW/MID 60S OVER THE
EASTERN SHORE...TO THE LOW 70S ALONG AND S OF THE VA/NC BORDER (AWAY
FROM THE COASTS). HIGHS WEDNESDAY SHOULD BE A FEW DEGREES COOLER
RANGING FROM THE LOW 60S OVER THE EASTERN SHORE (PERHAPS UPPER 50S
ALONG THE COAST) THE THE UPPER 60S S. LOW TEMPERATURES SHOULD REMAIN
IN THE 50S.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
LONG TERM PERIOD WILL BE CHARACTERIZED BY A STAGNANT BLOCKING
PATTERN WITH AN UPR-LVL RIDGE STRETCHED ALONG THE ERN SEABOARD. AT
THE SFC...HI PRES WILL PERSIST OVER THE MID ATLANTIC OR JUST
OFFSHORE LEADING TO LGT ONSHORE FLOW AND GENLY DRY CONDS. ADJUSTED
ANY CHC POPS DOWN TO SLGT CHC WITH UPR-LVL CUTOFF LO REMAINING WELL
OFFSHORE. OVERALL...STILL FAVORING THE SLIGHTLY SLOWER ECMWF GUIDANCE
WRT THE DEVELOPING CUTOFF LO OVER THE CENTRAL CONUS AS MODELS TEND
TO BREAK DOWN BLOCKING PATTERNS TOO SOON/PROGRESS CUTOFF LOWS TOO
QUICKLY. KEPT POPS CAPPED AT 20-30% OVER THE WEEKEND DUE TO ISSUES
WITH PRECIP TIMING WITH THE APPROACHING LO. AS FOR TEMPS...HIGHS AVG
IN THE UPR 60S/LWR 70S WITH LO TEMPS IN THE UPR 40S/LWR 50S.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
WIDESPREAD STRATIFORM RAIN CONTINUES TO MOVE SLIDE NW ACROSS
LOWER EASTERN SHORE/NORTHERN NECK THIS AFTN, WITH SOLID IFR/MVFR
CONDS ACROSS AREA TERMINALS. CIGS HAVE BEGUN TO RECOVER AS
EXPECTED WITH LOW CLOUDS GRADUALLY SCOURING OUT WEST OF RIC.
CONDITIONS IMPROVE TO MVFR/VFR AT RIC BY 21-22Z, ONLY TO FALL
BACK INTO IFR SHORTLY AFTER SUNSET, WITH LIFR CONDS POSSIBLE AFTER
06Z/2A TNGT. OVER COASTAL TERMINALS, EXPECT CIGS TO REMAIN IN MVFR
RANGE THROUGH THIS EVENING, FALLING TO IFR (LCL LIFR) IN LOW
CLOUDS/FOG TONIGHT.
OUTLOOK...IFR CONDITIONS DO GRADUALLY IMPROVE LATE TUE MORN.
HOWEVER, PERSISTENT NE FLOW SHOULD RESULT IN OCCASIONAL RAIN
SHOWERS WITH LINGERING LOW CLOUDS THROUGH WED, ESPECIALLY AT
COASTAL TERMINALS.
&&
.MARINE...
LOW PRESSURE APPROACHES THE AREA FROM THE WEST TODAY...THEN WEAKENS
AS IT CROSSES THE WATERS TONIGHT. LIGHT SE FLOW OVER THE WATERS
EARLY THIS MORNING WILL INCREASE DURING THE DAY TODAY DUE TO AN
INCREASING PRESSURE GRADIENT...ALLOWING FOR WINDS OF 15-20 KNOTS
OVER THE WATERS WITH SOME GUSTS UP TO 25 KT ON THE OCEAN. THE
EASTERLY COMPONENT TO THE WINDS WILL ALLOW SEAS TO BUILD ON THE
OCEAN...REACHING 5-6 BY LATE MORNING. SCA`S REMAIN IN PLACE FOR ALL
THE COASTAL WATERS (MAINLY FOR SEAS) TODAY THRU TUESDAY NIGHT. SCA`S
FOR THE CHES BAY/CURRITUCK SOUND CONTINUE THRU 7 PM THIS EVENING
WHEN THE PRESSURE GRADIENT SHOULD RELAX AND WINDS SUBSIDE. SFC HIGH
PRESSURE REMAINS LOCKED IN PLACE OVER NEW ENGLAND THRU THE COMING
WEEK ALLOWING FOR PERSISTENT E-NE WINDS OVER THE LOCAL WATERS.
ALTHOUGH WINDS WILL LIKELY REMAIN SUB-SCA DURING THIS TIME...SEAS
WILL REMAIN AOA 5 FT SO SCA`S WILL LIKELY CONTINUE FOR THE ENTIRE
WEEK.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR
ANZ630>634.
SMALL CRAFT ADVISORY UNTIL 7 AM EDT WEDNESDAY FOR ANZ650-652-
654-656-658.
&&
$$
SYNOPSIS...AJZ
NEAR TERM...AJZ/DAP
SHORT TERM...AJZ
LONG TERM...MAS
AVIATION...JDM/MAM
MARINE...JDM
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
1121 AM EDT MON APR 29 2013
.SYNOPSIS...
LOW PRESSURE LIFTS NORTHEAST ACROSS THE MID ATLANTIC TODAY AND OFF
THE COAST TONIGHT. LOW PRESSURE LINGERS OFF THE CAROLINA COAST
THROUGH MIDWEEK AS HIGH PRESSURE BUILDS OFF THE NEW ENGLAND COAST.
&&
.NEAR TERM /THROUGH TONIGHT/...
CURRENT RADAR TRENDS SHOWING PRECIP CONTINUING TO MOVE E/NE THIS
MORNING...WITH AREAS WEST OF RIC BEGINNING TO SEE SOME BREAKS IN THE
PRECIP. HAVE UPDATED POPS TO SHOW THIS TREND...BUT HAVE KEPT 30-50
PERCENT CHANCE OF PRECIP IN THE WEST TO ACCOUNT FOR -SHRA
DEVELOPMENT THIS AFTERNOON. OTHERWISE FORECAST LOOKS ON TARGET.
...PREVIOUS DISCUSSION...
THE LATEST RUC MAINTAINS THIS STRONG LIFT OVER THE LOCAL AREA
THROUGH 12Z BEFORE SHIFTING IT TOWARD THE EASTERN PORTION OF THE
AREA FROM 12-16Z AS THE JET CORE PULLS NE TOWARD LONG ISLAND AND
THE MID-LEVEL TROUGH AXIS INTRUDES FROM THE WEST. THIS SHOULD
ALLOW STEADY RAIN TO SLOWLY TAPER OFF W OF I-95 THROUGH THE
MORNING. THE MAIN AREA OF ASCENT THEN SHIFTS TO SE PORTIONS BY
AFTERNOON AS A SECONDARY SPEED MAX MOVES OVER CENTRAL VA. A FEW
RUMBLES OF THUNDER ARE POSSIBLE OVER SE PORTIONS GIVEN THAT THIS
FEATURE ARRIVES DURING THE AFTERNOON. HOWEVER...AMBIENT RAIN
COOLED STABLE CONDITIONS WILL LIMIT INSTABILITY (AND LIMIT THE
POTENTIAL OF DEEP CONVECTION) HENCE THUNDER WILL NOT BE INCLUDED
IN THE GRIDS. THE LATEST DATA SUGGESTS THAT QPF COULD REACH 1.5IN
AND POSSIBLY CLOSE TO 2.0IN FOR SOME LOCATIONS BY THIS AFTERNOON
ACROSS S-CENTRAL/SE VA/EASTERN SHORE/NE NC. THIS HAS FURTHER
SUPPORT FROM UPSTREAM OBS OVER CENTRAL NC WHERE AMOUNTS HAVE
REACHED 1.0-1.5IN AND RAIN CONTINUES.
THE MID-LEVEL TROUGH AXIS MOVES OFF THE COAST TONIGHT WITH THE
ASSOCIATED WIND FLOW BECOMING NW (ALBEIT WEAK). THIS SHOULD ALLOW
STEADY RAIN TO TAPER OFF TO SHOWERS THIS EVENING FOR EASTERN AREAS.
THERE IS AN ABUNDANT AMOUNT OF LINGERING LOW-LEVEL MOISTURE THAT
WILL NOT BE SCOURED OUT BY WEAK FLOW...SO WIDESPREAD STRATUS IS
EXPECTED TO DEVELOP. THIS COULD EVENTUALLY SETTLE TO THE SURFACE
RESULTING IN THE POTENTIAL FOR FOG.
CLOUD COVER AND RAIN WILL LIMIT HIGH TEMPERATURES TODAY...WITH
READINGS RANGING FROM THE LOW/MID 60S (UPPER 50S ALONG THE ATLANTIC
COAST) OVER THE EASTERN SHORE TO THE UPPER 60S/NEAR 70 S. LOWS
TONIGHT WILL BE MILD AND LARGELY BE IN THE MID 50S.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
HIGH PRESSURE RE-EXERTS ITSELF OVER THE CANADIAN MARITIMES TUESDAY
AND WEDNESDAY AND NUDGES SW ALONG THE NEW ENGLAND COAST.
MEANWHILE...A COASTAL TROUGH LINGERS OFF THE CAROLINA COAST. THIS
WILL MAINTAIN ONSHORE FLOW AND PERSISTENT MOSTLY CLOUDY TO OVERCAST
CONDITIONS. THE LATEST GFS/NAM/ECMWF DRAW MOISTURE AROUND THE
NORTHERN PERIPHERY OF THE TROUGH LATE TUESDAY NIGHT INTO WEDNESDAY
AHEAD OF A BACKDOOR FRONT. HOWEVER...CONFIDENCE IS LOW REGARDING
RAIN POTENTIAL AT THIS TIME...SO WILL GO WITH NO HIGHER THAN A 40
POP. THUNDER POTENTIAL SHOULD REMAIN VERY LIMITED DUE TO ONSHORE
FLOW AND SSTS IN THE LOW/MID 50S. IF ANY THUNDER WERE TO OCCUR
(MAINLY TUE) IT WOULD BE OVER INTERIOR NE NC AND S-CENTRAL VA.
AS FOR TEMPERATURES...THE COOLER MAV GUIDANCE HAS BEEN FOLLOWED AS
MET NUMBERS APPEAR TOO WARM BASED ON EXPECTED CLOUD COVER. THIS
RESULTS IN HIGHS TUESDAY RANGING FROM THE LOW/MID 60S OVER THE
EASTERN SHORE...TO THE LOW 70S ALONG AND S OF THE VA/NC BORDER (AWAY
FROM THE COASTS). HIGHS WEDNESDAY SHOULD BE A FEW DEGREES COOLER
RANGING FROM THE LOW 60S OVER THE EASTERN SHORE (PERHAPS UPPER 50S
ALONG THE COAST) THE THE UPPER 60S S. LOW TEMPERATURES SHOULD REMAIN
IN THE 50S.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
LONG TERM PERIOD WILL BE CHARACTERIZED BY A STAGNANT BLOCKING
PATTERN WITH AN UPR-LVL RIDGE STRETCHED ALONG THE ERN SEABOARD. AT
THE SFC...HI PRES WILL PERSIST OVER THE MID ATLANTIC OR JUST
OFFSHORE LEADING TO LGT ONSHORE FLOW AND GENLY DRY CONDS. ADJUSTED
ANY CHC POPS DOWN TO SLGT CHC WITH UPR-LVL CUTOFF LO REMAINING WELL
OFFSHORE. OVERALL...STILL FAVORING THE SLIGHTLY SLOWER ECMWF GUIDANCE
WRT THE DEVELOPING CUTOFF LO OVER THE CENTRAL CONUS AS MODELS TEND
TO BREAK DOWN BLOCKING PATTERNS TOO SOON/PROGRESS CUTOFF LOWS TOO
QUICKLY. KEPT POPS CAPPED AT 20-30% OVER THE WEEKEND DUE TO ISSUES
WITH PRECIP TIMING WITH THE APPROACHING LO. AS FOR TEMPS...HIGHS AVG
IN THE UPR 60S/LWR 70S WITH LO TEMPS IN THE UPR 40S/LWR 50S.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
WIDESPREAD RAIN CONTINUES ACRS THE LOCAL AREA THIS MORNING, WITH
IFR/MVFR (LCL LIFR IVOF SBY BETWEEN 12-15Z) TO LINGER THROUGH THE
DAY, AS LOW PRESSURE CONTINUES TO BRING RAIN TO THE AREA. EXPECT
CIGS TO BOUNCE BACK SOME BY THIS AFTN, AT LEAST TO HIGH END MVFR
AT RIC (POTENTIALLY VFR AFTER 18-20Z). OTHERWISE, SUB-VFR CONDS
PERSIST THROUGH THE TAF PERIOD AT COASTAL SITES, REMAINING IN
IFR-MVFR RANGE THROUGH THE DAY AT SBY-PHF-ORF-ECG. PCPN WL SLOWLY
TAPER OFF FROM WEST TO EAST TONIGHT BUT MAY NEVER TOTALLY END AT
THE COASTAL SITES UNTIL LATE TONIGHT.
OUTLOOK...DESPITE PCPN ENDING, DIMINISHING WINDS AND PLENTY OF
REMNANT LLVL MOISTURE SEEM TO POINT TOWARDS A RETURN OF IFR/LIFR
OVERNIGHT IN LOW CLOUDS/FOG OVERNIGHT. CONDITIONS DO GRADUALLY
IMPROVE ON TUESDAY. HOWEVER, PERSISTENT NE FLOW SHOULD RESULT IN
OCCASIONAL RAIN SHOWERS WITH LINGERING LOW CLOUDS, ESPECIALLY AT
COASTAL TERMINALS TUE/WED.
&&
.MARINE...
LOW PRESSURE APPROACHES THE AREA FROM THE WEST TODAY...THEN WEAKENS
AS IT CROSSES THE WATERS TONIGHT. LIGHT SE FLOW OVER THE WATERS
EARLY THIS MORNING WILL INCREASE DURING THE DAY TODAY DUE TO AN
INCREASING PRESSURE GRADIENT...ALLOWING FOR WINDS OF 15-20 KNOTS
OVER THE WATERS WITH SOME GUSTS UP TO 25 KT ON THE OCEAN. THE
EASTERLY COMPONENT TO THE WINDS WILL ALLOW SEAS TO BUILD ON THE
OCEAN...REACHING 5-6 BY LATE MORNING. SCA`S REMAIN IN PLACE FOR ALL
THE COASTAL WATERS (MAINLY FOR SEAS) TODAY THRU TUESDAY NIGHT. SCA`S
FOR THE CHES BAY/CURRITUCK SOUND CONTINUE THRU 7 PM THIS EVENING
WHEN THE PRESSURE GRADIENT SHOULD RELAX AND WINDS SUBSIDE. SFC HIGH
PRESSURE REMAINS LOCKED IN PLACE OVER NEW ENGLAND THRU THE COMING
WEEK ALLOWING FOR PERSISTENT E-NE WINDS OVER THE LOCAL WATERS.
ALTHOUGH WINDS WILL LIKELY REMAIN SUB-SCA DURING THIS TIME...SEAS
WILL REMAIN AOA 5 FT SO SCA`S WILL LIKELY CONTINUE FOR THE ENTIRE
WEEK.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR
ANZ630>634.
SMALL CRAFT ADVISORY UNTIL 7 AM EDT WEDNESDAY FOR ANZ650-652-
654-656-658.
&&
$$
SYNOPSIS...AJZ
NEAR TERM...AJZ/DAP
SHORT TERM...AJZ
LONG TERM...MAS
AVIATION...JDM/MAM
MARINE...JDM
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1057 AM EDT MON APR 29 2013
.SYNOPSIS...
ONE MORE UNSETTLED WEATHER DAY BEFORE HIGH PRESSURE TAKES CHARGE.
HIGH PRESSURE BUILDS INTO THE MID ATLANTIC AND CONTROLS OUR
WEATHER THROUGH THE WEEKEND. THE MIDDLE TO LATTER PART OF THE
WORK WEEK WILL BE THE WARMEST WITH TEMPERATURES 10 DEGREES ABOVE
NORMAL. COME THE WEEKEND...LOOK FOR HIGHS TO FALL BACK TO SEASONAL
NUMBERS.
&&
.NEAR TERM /THROUGH TONIGHT/...
SCATTERED TO NUMEROUS SHOWERS CONTINUE EAST OF THE OHIO RIVER.
HIGHEST POPS WILL REMAIN THERE THROUGH THE AFTERNOON. FOG IS SLOWLY
LIFTING BASED ON AREA WEB CAMS AND SFC REPORTING SITES IN GARRETT
COUNTY...SO NO NEED TO EXTEND FOG. SKY COVER AND RESULTANT
DAYTIME MAXT ARE THE MAIN FORECAST CHALLENGES. LATEST HRRR CLOUD
COVERAGE PROGS ILLUSTRATES SCT-BKN OPEN CELLULAR CLOUDS ACROSS THE
ENTIRE REGION THIS AFTERNOON ALLOWING THE MERCURY TO CLIMB INTO
THE L-M 60S. THIS CONCURS WITH EXISTING FORECAST...SO ONLY TWEAKS
NEEDED. IT ONLY TAKES A SHORT DURATION OF SUNSHINE TO JUMP TEMPS
INTO THE MID 60S /CASE IN POINT CENTRAL WV ALONG THE OHIO RIVER/.
AS TROUGH AXIS PASSES INTO CENTRAL PENNSYLVANIA THIS EVENING...CHANCE
FOR RAIN SHOULD RAPIDLY DECREASE. HOWEVER...ONLY EXPECT TO SEE
PARTIAL CLEARING WITH FLOW REMAINING OUT OF THE EAST-SOUTHEAST
BRINGING IN MOISTURE FROM THE ATLANTIC OCEAN. PARTLY CLOUDY SKIES
WILL KEEP TEMPERATURES FROM FALLING TOO MUCH...WHICH WILL KEEP
OVERNIGHT LOWS ABOVE GUIDANCE. WITH MOISTURE DEPTH AND AREAS THAT
EXPERIENCE PARTIAL CLEARING...PATCHY FOG WILL BE A CONCERN.
PARCEL TRAJECTORIES TONIGHT ARE FROM IND WHERE WIDESPREAD STRATUS
EXISTS.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
UPPER LEVEL HIGH WILL BEGIN TO ESTABLISH ITSELF ACROSS THE EAST
COAST DURING THE MIDDLE OF THE WORK WEEK WHILE BROAD UPPER LEVEL
TROUGH WILL REMAIN ACROSS THE WESTERN HALF OF THE UNITED STATES.
THIS WILL KEEP WIDESPREAD PRECIPITATION AWAY FROM THE REGION.
HOWEVER...EASTERLY LOW LEVEL FLOW WILL CONTINUE THROUGH THE
PERIOD...WITH ATLANTIC MOISTURE BRINGING CLOUDS AND RAIN EAST OF THE
LAUREL HIGHLANDS. THIS PATTERN SHOULD MANAGE TO KEEP SKIES AT LEAST
PARTLY CLOUDY...AND AN ISOLATED SHOWER CANNOT BE RULED OUT RIGHT
ALONG THE RIDGES. DURING THESE TWO DAYS...TEMPERATURES WILL REMAIN
NEAR NORMAL IN THE CLOUDY EASTERN COUNTIES...AND TEMPERATURES UP TO
10 DEGREES ABOVE NORMAL ARE EXPECTED IN THE SUNNIER WESTERN COUNTIES
OUT IN OHIO.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
MODELS STILL IN GENERAL AGREEMENT ON A BLOCKED UPPER LEVEL
PATTERN THROUGH THE EXTENDED AS A POWERFUL COLD CLOSED LOW DIVES
INTO THE NATIONS MID SECTION WITH A CLOSED RIDGE ALOFT ACROSS THE
NORTHEASTERN STATES. NOT A GREAT DEAL OF CHANGE TO PREVIOUS
FORECAST WITH EAST COAST HIGH PRESSURE KEEPING REGION DRY THROUGH
THE WORK WEEK. BY THE WEEKEND MODELS DO DIFFER ON HOW FAST
BLOCKED PATTERN WILL BREAK. A COMPROMISE SOLUTION TOWARD THE HPC
GRIDS BRINGS IN A CHANCE FOR SHOWERS MAINLY SUNDAY AS OCCLUDED
FRONTAL BOUNDARY MOVES INTO REGION AS RIDGE WEAKENS AND CLOSED LOW
BEGINS TO SHIFT EAST. TEMPERATURES WILL TREND BACK TOWARD NORMAL
BY THE WEEKEND.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
MVFR CIGS WILL BE THE RULE THROUGH THE AFTERNOON. MVFR VIS
RESTRICTIONS COULD OCCUR AT FKL/DUJ/PIT/LBE WITH A PASSING SHOWER
THROUGH 21Z. CIGS WILL LIFT TO VFR THIS EVENING AS HIGH PRESSURE
SLOWLY WORKS INTO THE REGION.
LOWER CONFIDENCE ON VIS AND CIGS DURING THE PREDAWN HOURS.
DEPENDING HOW MANY TERMINALS CLEAR OUT WILL DETERMINE HOW
WIDESPREAD OR PATCHY THE FOG IS. IF CLEARING DOES NOT OCCUR
TONIGHT...NEITHER WOULD IFR WX. AFTER ANY MORNING FOG LIFTS LOOK
FOR VFR CONDS TUE.
.OUTLOOK.../MONDAY NIGHT THROUGH FRIDAY/...
NO WIDESPREAD IFR WEATHER FORECAST.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
SYNOPSIS...98
NEAR TERM...98/34
SHORT TERM...34
AVIATION...98
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
759 AM EDT MON APR 29 2013
.SYNOPSIS...
LOW PRESSURE LIFTS NORTHEAST ACROSS THE MID ATLANTIC TODAY AND OFF
THE COAST TONIGHT. LOW PRESSURE LINGERS OFF THE CAROLINA COAST
THROUGH MIDWEEK AS HIGH PRESSURE BUILDS OFF THE NEW ENGLAND COAST.
&&
.NEAR TERM /THROUGH TONIGHT/...
CURRENT WATER VAPOR IMAGERY INDICATES A MOIST FRONTAL BAND EXTENDING
FROM THE NORTHERN GULF COAST THROUGH THE MID ATLANTIC AHEAD OF A
MID-LEVEL TROUGH OVER THE OHIO VALLEY. VIGOROUS VERTICAL ASCENT...IN
THE RRQ OF AN 85KT JET CORE OVER THE SUSQUEHANNA VALLEY OF PA (PER
29/06Z RUC) HAS RESULTED IN WIDESPREAD RAIN FROM FROM SC TO NJ AS OF
0730Z. THE LATEST RUC MAINTAINS THIS STRONG LIFT OVER THE LOCAL AREA
THROUGH 12Z BEFORE SHIFTING IT TOWARD THE EASTERN PORTION OF THE
AREA FROM 12-16Z AS THE JET CORE PULLS NE TOWARD LONG ISLAND AND THE
MID-LEVEL TROUGH AXIS INTRUDES FROM THE WEST. THIS SHOULD ALLOW
STEADY RAIN TO SLOWLY TAPER OFF W OF I-95 THROUGH THE MORNING. THE
MAIN AREA OF ASCENT THEN SHIFTS TO SE PORTIONS BY AFTERNOON AS A
SECONDARY SPEED MAX MOVES OVER CENTRAL VA. A FEW RUMBLES OF THUNDER
ARE POSSIBLE OVER SE PORTIONS GIVEN THAT THIS FEATURE ARRIVES DURING
THE AFTERNOON. HOWEVER...AMBIENT RAIN COOLED STABLE CONDITIONS WILL
LIMIT INSTABILITY (AND LIMIT THE POTENTIAL OF DEEP CONVECTION) HENCE
THUNDER WILL NOT BE INCLUDED IN THE GRIDS. THE LATEST DATA SUGGESTS
THAT QPF COULD REACH 1.5IN AND POSSIBLY CLOSE TO 2.0IN FOR SOME
LOCATIONS BY THIS AFTERNOON ACROSS S-CENTRAL/SE VA/EASTERN SHORE/NE
NC. THIS HAS FURTHER SUPPORT FROM UPSTREAM OBS OVER CENTRAL NC WHERE
AMOUNTS HAVE REACHED 1.0-1.5IN AND RAIN CONTINUES.
THE MID-LEVEL TROUGH AXIS MOVES OFF THE COAST TONIGHT WITH THE
ASSOCIATED WIND FLOW BECOMING NW (ALBEIT WEAK). THIS SHOULD ALLOW
STEADY RAIN TO TAPER OFF TO SHOWERS THIS EVENING FOR EASTERN AREAS.
THERE IS AN ABUNDANT AMOUNT OF LINGERING LOW-LEVEL MOISTURE THAT
WILL NOT BE SCOURED OUT BY WEAK FLOW...SO WIDESPREAD STRATUS IS
EXPECTED TO DEVELOP. THIS COULD EVENTUALLY SETTLE TO THE SURFACE
RESULTING IN THE POTENTIAL FOR FOG.
CLOUD COVER AND RAIN WILL LIMIT HIGH TEMPERATURES TODAY...WITH
READINGS RANGING FROM THE LOW/MID 60S (UPPER 50S ALONG THE ATLANTIC
COAST) OVER THE EASTERN SHORE TO THE UPPER 60S/NEAR 70 S. LOWS
TONIGHT WILL BE MILD AND LARGELY BE IN THE MID 50S.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
HIGH PRESSURE RE-EXERTS ITSELF OVER THE CANADIAN MARITIMES TUESDAY
AND WEDNESDAY AND NUDGES SW ALONG THE NEW ENGLAND COAST.
MEANWHILE...A COASTAL TROUGH LINGERS OFF THE CAROLINA COAST. THIS
WILL MAINTAIN ONSHORE FLOW AND PERSISTENT MOSTLY CLOUDY TO OVERCAST
CONDITIONS. THE LATEST GFS/NAM/ECMWF DRAW MOISTURE AROUND THE
NORTHERN PERIPHERY OF THE TROUGH LATE TUESDAY NIGHT INTO WEDNESDAY
AHEAD OF A BACKDOOR FRONT. HOWEVER...CONFIDENCE IS LOW REGARDING
RAIN POTENTIAL AT THIS TIME...SO WILL GO WITH NO HIGHER THAN A 40
POP. THUNDER POTENTIAL SHOULD REMAIN VERY LIMITED DUE TO ONSHORE
FLOW AND SSTS IN THE LOW/MID 50S. IF ANY THUNDER WERE TO OCCUR
(MAINLY TUE) IT WOULD BE OVER INTERIOR NE NC AND S-CENTRAL VA.
AS FOR TEMPERATURES...THE COOLER MAV GUIDANCE HAS BEEN FOLLOWED AS
MET NUMBERS APPEAR TOO WARM BASED ON EXPECTED CLOUD COVER. THIS
RESULTS IN HIGHS TUESDAY RANGING FROM THE LOW/MID 60S OVER THE
EASTERN SHORE...TO THE LOW 70S ALONG AND S OF THE VA/NC BORDER (AWAY
FROM THE COASTS). HIGHS WEDNESDAY SHOULD BE A FEW DEGREES COOLER
RANGING FROM THE LOW 60S OVER THE EASTERN SHORE (PERHAPS UPPER 50S
ALONG THE COAST) THE THE UPPER 60S S. LOW TEMPERATURES SHOULD REMAIN
IN THE 50S.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
LONG TERM PERIOD WILL BE CHARACTERIZED BY A STAGNANT BLOCKING
PATTERN WITH AN UPR-LVL RIDGE STRETCHED ALONG THE ERN SEABOARD. AT
THE SFC...HI PRES WILL PERSIST OVER THE MID ATLANTIC OR JUST
OFFSHORE LEADING TO LGT ONSHORE FLOW AND GENLY DRY CONDS. ADJUSTED
ANY CHC POPS DOWN TO SLGT CHC WITH UPR-LVL CUTOFF LO REMAINING WELL
OFFSHORE. OVERALL...STILL FAVORING THE SLIGHTLY SLOWER ECMWF GUIDANCE
WRT THE DEVELOPING CUTOFF LO OVER THE CENTRAL CONUS AS MODELS TEND
TO BREAK DOWN BLOCKING PATTERNS TOO SOON/PROGRESS CUTOFF LOWS TOO
QUICKLY. KEPT POPS CAPPED AT 20-30% OVER THE WEEKEND DUE TO ISSUES
WITH PRECIP TIMING WITH THE APPROACHING LO. AS FOR TEMPS...HIGHS AVG
IN THE UPR 60S/LWR 70S WITH LO TEMPS IN THE UPR 40S/LWR 50S.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
WIDESPREAD RAIN CONTINUES ACRS THE LOCAL AREA THIS MORNING, WITH
IFR/MVFR (LCL LIFR IVOF SBY BETWEEN 12-15Z) TO LINGER THROUGH THE
DAY, AS LOW PRESSURE CONTINUES TO BRING RAIN TO THE AREA. EXPECT
CIGS TO BOUNCE BACK SOME BY THIS AFTN, AT LEAST TO HIGH END MVFR
AT RIC (POTENTIALLY VFR AFTER 18-20Z). OTHERWISE, SUB-VFR CONDS
PERSIST THROUGH THE TAF PERIOD AT COASTAL SITES, REMAINING IN
IFR-MVFR RANGE THROUGH THE DAY AT SBY-PHF-ORF-ECG. PCPN WL SLOWLY
TAPER OFF FROM WEST TO EAST TONIGHT BUT MAY NEVER TOTALLY END AT
THE COASTAL SITES UNTIL LATE TONIGHT.
OUTLOOK...DESPITE PCPN ENDING, DIMINISHING WINDS AND PLENTY OF
REMNANT LLVL MOISTURE SEEM TO POINT TOWARDS A RETURN OF IFR/LIFR
OVERNIGHT IN LOW CLOUDS/FOG OVERNIGHT. CONDITIONS DO GRADUALLY
IMPROVE ON TUESDAY. HOWEVER, PERSISTENT NE FLOW SHOULD RESULT IN
OCCASIONAL RAIN SHOWERS WITH LINGERING LOW CLOUDS, ESPECIALLY AT
COASTAL TERMINALS TUE/WED.
&&
.MARINE...
LOW PRESSURE APPROACHES THE AREA FROM THE WEST TODAY...THEN WEAKENS
AS IT CROSSES THE WATERS TONIGHT. LIGHT SE FLOW OVER THE WATERS
EARLY THIS MORNING WILL INCREASE DURING THE DAY TODAY DUE TO AN
INCREASING PRESSURE GRADIENT...ALLOWING FOR WINDS OF 15-20 KNOTS
OVER THE WATERS WITH SOME GUSTS UP TO 25 KT ON THE OCEAN. THE
EASTERLY COMPONENT TO THE WINDS WILL ALLOW SEAS TO BUILD ON THE
OCEAN...REACHING 5-6 BY LATE MORNING. SCA`S REMAIN IN PLACE FOR ALL
THE COASTAL WATERS (MAINLY FOR SEAS) TODAY THRU TUESDAY NIGHT. SCA`S
FOR THE CHES BAY/CURRITUCK SOUND CONTINUE THRU 7 PM THIS EVENING
WHEN THE PRESSURE GRADIENT SHOULD RELAX AND WINDS SUBSIDE. SFC HIGH
PRESSURE REMAINS LOCKED IN PLACE OVER NEW ENGLAND THRU THE COMING
WEEK ALLOWING FOR PERSISTENT E-NE WINDS OVER THE LOCAL WATERS.
ALTHOUGH WINDS WILL LIKELY REMAIN SUB-SCA DURING THIS TIME...SEAS
WILL REMAIN AOA 5 FT SO SCA`S WILL LIKELY CONTINUE FOR THE ENTIRE
WEEK.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR
ANZ630>634.
SMALL CRAFT ADVISORY UNTIL 7 AM EDT WEDNESDAY FOR ANZ650-652-
654-656-658.
&&
$$
SYNOPSIS...AJZ
NEAR TERM...AJZ
SHORT TERM...AJZ
LONG TERM...MAS
AVIATION...JDM/MAM
MARINE...JDM
AREA FORECAST DISCUSSION...CORRECTED
NWS WAKEFIELD VA
412 AM EDT MON APR 29 2013
.SYNOPSIS...
LOW PRESSURE LIFTS NORTHEAST ACROSS THE MID ATLANTIC TODAY AND OFF
THE COAST TONIGHT. LOW PRESSURE LINGERS OFF THE CAROLINA COAST
THROUGH MIDWEEK AS HIGH PRESSURE BUILDS OFF THE NEW ENGLAND COAST.
&&
.NEAR TERM /THROUGH TONIGHT/...
CURRENT WATER VAPOR IMAGERY INDICATES A MOIST FRONTAL BAND EXTENDING
FROM THE NORTHERN GULF COAST THROUGH THE MID ATLANTIC AHEAD OF A
MID-LEVEL TROUGH OVER THE OHIO VALLEY. VIGOROUS VERTICAL ASCENT...IN
THE RRQ OF AN 85KT JET CORE OVER THE SUSQUEHANNA VALLEY OF PA (PER
29/06Z RUC) HAS RESULTED IN WIDESPREAD RAIN FROM FROM SC TO NJ AS OF
0730Z. THE LATEST RUC MAINTAINS THIS STRONG LIFT OVER THE LOCAL AREA
THROUGH 12Z BEFORE SHIFTING IT TOWARD THE EASTERN PORTION OF THE
AREA FROM 12-16Z AS THE JET CORE PULLS NE TOWARD LONG ISLAND AND THE
MID-LEVEL TROUGH AXIS INTRUDES FROM THE WEST. THIS SHOULD ALLOW
STEADY RAIN TO SLOWLY TAPER OFF W OF I-95 THROUGH THE MORNING. THE
MAIN AREA OF ASCENT THEN SHIFTS TO SE PORTIONS BY AFTERNOON AS A
SECONDARY SPEED MAX MOVES OVER CENTRAL VA. A FEW RUMBLES OF THUNDER
ARE POSSIBLE OVER SE PORTIONS GIVEN THAT THIS FEATURE ARRIVES DURING
THE AFTERNOON. HOWEVER...AMBIENT RAIN COOLED STABLE CONDITIONS WILL
LIMIT INSTABILITY (AND LIMIT THE POTENTIAL OF DEEP CONVECTION) HENCE
THUNDER WILL NOT BE INCLUDED IN THE GRIDS. THE LATEST DATA SUGGESTS
THAT QPF COULD REACH 1.5IN AND POSSIBLY CLOSE TO 2.0IN FOR SOME
LOCATIONS BY THIS AFTERNOON ACROSS S-CENTRAL/SE VA/EASTERN SHORE/NE
NC. THIS HAS FURTHER SUPPORT FROM UPSTREAM OBS OVER CENTRAL NC WHERE
AMOUNTS HAVE REACHED 1.0-1.5IN AND RAIN CONTINUES.
THE MID-LEVEL TROUGH AXIS MOVES OFF THE COAST TONIGHT WITH THE
ASSOCIATED WIND FLOW BECOMING NW (ALBEIT WEAK). THIS SHOULD ALLOW
STEADY RAIN TO TAPER OFF TO SHOWERS THIS EVENING FOR EASTERN AREAS.
THERE IS AN ABUNDANT AMOUNT OF LINGERING LOW-LEVEL MOISTURE THAT
WILL NOT BE SCOURED OUT BY WEAK FLOW...SO WIDESPREAD STRATUS IS
EXPECTED TO DEVELOP. THIS COULD EVENTUALLY SETTLE TO THE SURFACE
RESULTING IN THE POTENTIAL FOR FOG.
CLOUD COVER AND RAIN WILL LIMIT HIGH TEMPERATURES TODAY...WITH
READINGS RANGING FROM THE LOW/MID 60S (UPPER 50S ALONG THE ATLANTIC
COAST) OVER THE EASTERN SHORE TO THE UPPER 60S/NEAR 70 S. LOWS
TONIGHT WILL BE MILD AND LARGELY BE IN THE MID 50S.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
HIGH PRESSURE RE-EXERTS ITSELF OVER THE CANADIAN MARITIMES TUESDAY
AND WEDNESDAY AND NUDGES SW ALONG THE NEW ENGLAND COAST.
MEANWHILE...A COASTAL TROUGH LINGERS OFF THE CAROLINA COAST. THIS
WILL MAINTAIN ONSHORE FLOW AND PERSISTENT MOSTLY CLOUDY TO OVERCAST
CONDITIONS. THE LATEST GFS/NAM/ECMWF DRAW MOISTURE AROUND THE
NORTHERN PERIPHERY OF THE TROUGH LATE TUESDAY NIGHT INTO WEDNESDAY
AHEAD OF A BACKDOOR FRONT. HOWEVER...CONFIDENCE IS LOW REGARDING
RAIN POTENTIAL AT THIS TIME...SO WILL GO WITH NO HIGHER THAN A 40
POP. THUNDER POTENTIAL SHOULD REMAIN VERY LIMITED DUE TO ONSHORE
FLOW AND SSTS IN THE LOW/MID 50S. IF ANY THUNDER WERE TO OCCUR
(MAINLY TUE) IT WOULD BE OVER INTERIOR NE NC AND S-CENTRAL VA.
AS FOR TEMPERATURES...THE COOLER MAV GUIDANCE HAS BEEN FOLLOWED AS
MET NUMBERS APPEAR TOO WARM BASED ON EXPECTED CLOUD COVER. THIS
RESULTS IN HIGHS TUESDAY RANGING FROM THE LOW/MID 60S OVER THE
EASTERN SHORE...TO THE LOW 70S ALONG AND S OF THE VA/NC BORDER (AWAY
FROM THE COASTS). HIGHS WEDNESDAY SHOULD BE A FEW DEGREES COOLER
RANGING FROM THE LOW 60S OVER THE EASTERN SHORE (PERHAPS UPPER 50S
ALONG THE COAST) THE THE UPPER 60S S. LOW TEMPERATURES SHOULD REMAIN
IN THE 50S.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
LONG TERM PERIOD WILL BE CHARACTERIZED BY A STAGNANT BLOCKING
PATTERN WITH AN UPR-LVL RIDGE STRETCHED ALONG THE ERN SEABOARD. AT
THE SFC...HI PRES WILL PERSIST OVER THE MID ATLANTIC OR JUST
OFFSHORE LEADING TO LGT ONSHORE FLOW AND GENLY DRY CONDS. ADJUSTED
ANY CHC POPS DOWN TO SLGT CHC WITH UPR-LVL CUTOFF LO REMAINING WELL
OFFSHORE. OVERALL...STILL FAVORING THE SLIGHTLY SLOWER ECMWF GUIDANCE
WRT THE DEVELOPING CUTOFF LO OVER THE CENTRAL CONUS AS MODELS TEND
TO BREAK DOWN BLOCKING PATTERNS TOO SOON/PROGRESS CUTOFF LOWS TOO
QUICKLY. KEPT POPS CAPPED AT 20-30% OVER THE WEEKEND DUE TO ISSUES
WITH PRECIP TIMING WITH THE APPROACHING LO. AS FOR TEMPS...HIGHS AVG
IN THE UPR 60S/LWR 70S WITH LO TEMPS IN THE UPR 40S/LWR 50S.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
STEADIER PCPN HAS BEGUN TO MOVE INTO THE LOCAL AREA EARLY THIS
MORNING WITH MVFR CONDITIONS STARTING TO SHOW UP AT THE TAF SITES.
IFR CONDITIONS ARE EXPECTED TO ARRIVE AROUND DAYBREAK AT KRIC AND
AT ALL OTHER TAF SITES BETWEEN 12-14Z THIS MORNING. IFR CONDITIONS
ARE THEN EXPECTED TO LINGER THE REMAINDER OF THE DAY AS LOW
PRESSURE CONTINUES TO BRING RAIN TO THE AREA. PCPN TRIES TO SLOWLY
TAPER OFF FROM WEST TO EAST TONIGHT BUT MAY NEVER TOTALLY END AT
THE COASTAL SITES. NEVERTHELESS...IFR CIGS EXPECTED TO CONTINUE
INTO TONIGHT. THERE CAN ALSO BE SOME BRIEF IFR CONDITIONS EARLY
THIS MORNING IN BOUTS OF STEADIER RAIN.
OUTLOOK...CONDITIONS IMPROVE ON TUESDAY BUT CHANCES OF RAIN WILL
CONTINUE INTO WEDNESDAY.
&&
.MARINE...
LOW PRESSURE APPROACHES THE AREA FROM THE WEST TODAY...THEN WEAKENS
AS IT CROSSES THE WATERS TONIGHT. LIGHT SE FLOW OVER THE WATERS
EARLY THIS MORNING WILL INCREASE DURING THE DAY TODAY DUE TO AN
INCREASING PRESSURE GRADIENT...ALLOWING FOR WINDS OF 15-20 KNOTS
OVER THE WATERS WITH SOME GUSTS UP TO 25 KT ON THE OCEAN. THE
EASTERLY COMPONENT TO THE WINDS WILL ALLOW SEAS TO BUILD ON THE
OCEAN...REACHING 5-6 BY LATE MORNING. SCA`S REMAIN IN PLACE FOR ALL
THE COASTAL WATERS (MAINLY FOR SEAS) TODAY THRU TUESDAY NIGHT. SCA`S
FOR THE CHES BAY/CURRITUCK SOUND CONTINUE THRU 7 PM THIS EVENING
WHEN THE PRESSURE GRADIENT SHOULD RELAX AND WINDS SUBSIDE. SFC HIGH
PRESSURE REMAINS LOCKED IN PLACE OVER NEW ENGLAND THRU THE COMING
WEEK ALLOWING FOR PERSISTENT E-NE WINDS OVER THE LOCAL WATERS.
ALTHOUGH WINDS WILL LIKELY REMAIN SUB-SCA DURING THIS TIME...SEAS
WILL REMAIN AOA 5 FT SO SCA`S WILL LIKELY CONTINUE FOR THE ENTIRE
WEEK.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR
ANZ630>634.
SMALL CRAFT ADVISORY UNTIL 7 AM EDT WEDNESDAY FOR ANZ650-652-
654-656-658.
&&
$$
SYNOPSIS...AJZ
NEAR TERM...AJZ
SHORT TERM...AJZ
LONG TERM...MAS
AVIATION...JDM/LSA
MARINE...JDM
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
411 AM EDT MON APR 29 2013
.SYNOPSIS...
LOW PRESSURE LIFTS NORTHEAST ACROSS THE MID ATLANTIC TODAY AND OFF
THE COAST TONIGHT. LOW PRESSURE LINGERS OFF THE CAROLINA COAST
THROUGH MIDWEEK AS HIGH PRESSURE BUILDS OFF THE NEW ENGLAND COAST.
&&
.NEAR TERM /THROUGH TONIGHT/...
CURRENT WATER VAPOR IMAGERY INDICATES A MOIST FRONTAL BAND EXTENDING
FROM THE NORTHERN GULF COAST THROUGH THE MID ATLANTIC AHEAD OF A
MID-LEVEL TROUGH OVER THE OHIO VALLEY. VIGOROUS VERTICAL ASCENT...IN
THE RRQ OF AN 85KT JET CORE OVER THE SUSQUEHANNA VALLEY OF PA (PER
29/06Z RUC) HAS RESULTED IN WIDESPREAD RAIN FROM FROM SC TO NJ AS OF
0730Z. THE LATEST RUC MAINTAINS THIS STRONG LIFT OVER THE LOCAL AREA
THROUGH 12Z BEFORE SHIFTING IT TOWARD THE EASTERN PORTION OF THE
AREA FROM 12-16Z AS THE JET CORE PULLS NE TOWARD LONG ISLAND AND THE
MID-LEVEL TROUGH AXIS INTRUDES FROM THE WEST. THIS SHOULD ALLOW
STEADY RAIN TO SLOWLY TAPER OFF W OF I-95 THROUGH THE MORNING. THE
MAIN AREA OF ASCENT THEN SHIFTS TO SE PORTIONS BY AFTERNOON AS A
SECONDARY SPEED MAX MOVES OVER CENTRAL VA. A FEW RUMBLES OF THUNDER
ARE POSSIBLE OVER SE PORTIONS GIVEN THAT THIS FEATURE ARRIVES DURING
THE AFTERNOON. HOWEVER...AMBIENT RAIN COOLED STABLE CONDITIONS WILL
LIMIT INSTABILITY (AND LIMIT THE POTENTIAL OF DEEP CONVECTION) HENCE
THUNDER WILL NOT BE INCLUDED IN THE GRIDS. THE LATEST DATA SUGGESTS
THAT QPF COULD REACH 1.5IN AND POSSIBLE CLOSE TO 2.0IN FOR SOME
LOCATIONS BY THIS AFTERNOON ACROSS S-CENTRAL/SE VA/EASTERN SHORE/NE
NC. THIS HAS FURTHER SUPPORT FROM UPSTREAM OBS OVER CENTRAL NC WHERE
AMOUNTS HAVE REACHED 1.0-1.5IN AND RAIN CONTINUES.
THE MID-LEVEL TROUGH AXIS MOVES OFF THE COAST TONIGHT WITH THE
ASSOCIATED WIND FLOW BECOMING NW (ALBEIT WEAK). THIS SHOULD ALLOW
STEADY RAIN TO TAPER OFF TO SHOWERS THIS EVENING FOR EASTERN AREAS.
THERE IS AN ABUNDANT AMOUNT OF LINGERING LOW-LEVEL MOISTURE THAT
WILL NOT BE SCOURED OUT BY WEAK FLOW...SO WIDESPREAD STRATUS IS
EXPECTED TO DEVELOP. THIS COULD EVENTUALLY SETTLE TO THE SURFACE
RESULTING IN THE POTENTIAL FOR FOG.
CLOUD COVER AND RAIN WILL LIMIT HIGH TEMPERATURES TODAY...WITH
READINGS RANGING FROM THE LOW/MID 60S (UPPER 50S ALONG THE ATLANTIC
COAST) OVER THE EASTERN SHORE TO THE UPPER 60S/NEAR 70 S. LOWS
TONIGHT WILL BE MILD AND LARGELY BE IN THE MID 50S.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
HIGH PRESSURE RE-EXERTS ITSELF OVER THE CANADIAN MARITIMES TUESDAY
AND WEDNESDAY AND NUDGES SW ALONG THE NEW ENGLAND COAST.
MEANWHILE...A COASTAL TROUGH LINGERS OFF THE CAROLINA COAST. THIS
WILL MAINTAIN ONSHORE FLOW AND PERSISTENT MOSTLY CLOUDY TO OVERCAST
CONDITIONS. THE LATEST GFS/NAM/ECMWF DRAW MOISTURE AROUND THE
NORTHERN PERIPHERY OF THE TROUGH LATE TUESDAY NIGHT INTO WEDNESDAY
AHEAD OF A BACKDOOR FRONT. HOWEVER...CONFIDENCE IS LOW REGARDING
RAIN POTENTIAL AT THIS TIME...SO WILL GO WITH NO HIGHER THAN A 40
POP. THUNDER POTENTIAL SHOULD REMAIN VERY LIMITED DUE TO ONSHORE
FLOW AND SSTS IN THE LOW/MID 50S. IF ANY THUNDER WERE TO OCCUR
(MAINLY TUE) IT WOULD BE OVER INTERIOR NE NC AND S-CENTRAL VA.
AS FOR TEMPERATURES...THE COOLER MAV GUIDANCE HAS BEEN FOLLOWED AS
MET NUMBERS APPEAR TOO WARM BASED ON EXPECTED CLOUD COVER. THIS
RESULTS IN HIGHS TUESDAY RANGING FROM THE LOW/MID 60S OVER THE
EASTERN SHORE...TO THE LOW 70S ALONG AND S OF THE VA/NC BORDER (AWAY
FROM THE COASTS). HIGHS WEDNESDAY SHOULD BE A FEW DEGREES COOLER
RANGING FROM THE LOW 60S OVER THE EASTERN SHORE (PERHAPS UPPER 50S
ALONG THE COAST) THE THE UPPER 60S S. LOW TEMPERATURES SHOULD REMAIN
IN THE 50S.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
LONG TERM PERIOD WILL BE CHARACTERIZED BY A STAGNANT BLOCKING
PATTERN WITH AN UPR-LVL RIDGE STRETCHED ALONG THE ERN SEABOARD. AT
THE SFC...HI PRES WILL PERSIST OVER THE MID ATLANTIC OR JUST
OFFSHORE LEADING TO LGT ONSHORE FLOW AND GENLY DRY CONDS. ADJUSTED
ANY CHC POPS DOWN TO SLGT CHC WITH UPR-LVL CUTOFF LO REMAINING WELL
OFFSHORE. OVERALL...STILL FAVORING THE SLIGHTLY SLOWER ECMWF GUIDANCE
WRT THE DEVELOPING CUTOFF LO OVER THE CENTRAL CONUS AS MODELS TEND
TO BREAK DOWN BLOCKING PATTERNS TOO SOON/PROGRESS CUTOFF LOWS TOO
QUICKLY. KEPT POPS CAPPED AT 20-30% OVER THE WEEKEND DUE TO ISSUES
WITH PRECIP TIMING WITH THE APPROACHING LO. AS FOR TEMPS...HIGHS AVG
IN THE UPR 60S/LWR 70S WITH LO TEMPS IN THE UPR 40S/LWR 50S.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
STEADIER PCPN HAS BEGUN TO MOVE INTO THE LOCAL AREA EARLY THIS
MORNING WITH MVFR CONDITIONS STARTING TO SHOW UP AT THE TAF SITES.
IFR CONDITIONS ARE EXPECTED TO ARRIVE AROUND DAYBREAK AT KRIC AND
AT ALL OTHER TAF SITES BETWEEN 12-14Z THIS MORNING. IFR CONDITIONS
ARE THEN EXPECTED TO LINGER THE REMAINDER OF THE DAY AS LOW
PRESSURE CONTINUES TO BRING RAIN TO THE AREA. PCPN TRIES TO SLOWLY
TAPER OFF FROM WEST TO EAST TONIGHT BUT MAY NEVER TOTALLY END AT
THE COASTAL SITES. NEVERTHELESS...IFR CIGS EXPECTED TO CONTINUE
INTO TONIGHT. THERE CAN ALSO BE SOME BRIEF IFR CONDITIONS EARLY
THIS MORNING IN BOUTS OF STEADIER RAIN.
OUTLOOK...CONDITIONS IMPROVE ON TUESDAY BUT CHANCES OF RAIN WILL
CONTINUE INTO WEDNESDAY.
&&
.MARINE...
LOW PRESSURE APPROACHES THE AREA FROM THE WEST TODAY...THEN WEAKENS
AS IT CROSSES THE WATERS TONIGHT. LIGHT SE FLOW OVER THE WATERS
EARLY THIS MORNING WILL INCREASE DURING THE DAY TODAY DUE TO AN
INCREASING PRESSURE GRADIENT...ALLOWING FOR WINDS OF 15-20 KNOTS
OVER THE WATERS WITH SOME GUSTS UP TO 25 KT ON THE OCEAN. THE
EASTERLY COMPONENT TO THE WINDS WILL ALLOW SEAS TO BUILD ON THE
OCEAN...REACHING 5-6 BY LATE MORNING. SCA`S REMAIN IN PLACE FOR ALL
THE COASTAL WATERS (MAINLY FOR SEAS) TODAY THRU TUESDAY NIGHT. SCA`S
FOR THE CHES BAY/CURRITUCK SOUND CONTINUE THRU 7 PM THIS EVENING
WHEN THE PRESSURE GRADIENT SHOULD RELAX AND WINDS SUBSIDE. SFC HIGH
PRESSURE REMAINS LOCKED IN PLACE OVER NEW ENGLAND THRU THE COMING
WEEK ALLOWING FOR PERSISTENT E-NE WINDS OVER THE LOCAL WATERS.
ALTHOUGH WINDS WILL LIKELY REMAIN SUB-SCA DURING THIS TIME...SEAS
WILL REMAIN AOA 5 FT SO SCA`S WILL LIKELY CONTINUE FOR THE ENTIRE
WEEK.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR
ANZ630>634.
SMALL CRAFT ADVISORY UNTIL 7 AM EDT WEDNESDAY FOR ANZ650-652-
654-656-658.
&&
$$
SYNOPSIS...AJZ
NEAR TERM...AJZ
SHORT TERM...AJZ
LONG TERM...MAS
AVIATION...JDM/LSA
MARINE...JDM
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
746 PM EDT TUE APR 30 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 432 PM EDT TUE APR 30 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD MID/UPPER LEVEL TROUGH
OVER THE NW CONUS RESULTING IN SW FLOW FROM THE CNTRL PLAINS TO THE
NRN GREAT LAKES. A VIGOROUS SHORTWAVE IN THIS SW FLOW ALOFT WAS
LIFTING NORTH INTO NW ONTARIO. AT THE SFC...LOW PRES WAS LOCATED
OVER NW ONTARIO WITH A COLD FRONT EXTENDING SOUTH INTO FAR WRN LAKE
SUPERIOR AND NW WI. A WARM FRONT WAS DRAPED ACROSS NCNTRL AND NE WI.
BULGE OF WARM DRY AIR AT AROUND 850 MB AS NOTED ON 12Z GRB SNDG AND
LATEST RAPID RUC SNDGS AT KIMT HAS PRODUCED SEVERAL HUNDRED J/KG OF
CIN....KEEPING ATMOSPHERE CAPPED ENOUGH TO PROHIBIT SHOWERS FROM
FORMING OVER MUCH OF THE FCST AREA SO FAR THIS AFTERNOON. JUST IN
LATEST RADAR VOLUME SCAN STARTING TO SEE A FEW SHOWERS POPPING OVER
HOUGHTON COUNTY BUT WITH ONLY AROUND 200-300 J/KG OF MLCAPE NOT
REALLY EXPECTED MUCH IN WAY OF THUNDER.
AS MODELS SHOW FRONT MOVG SLOWLY EAST INTO CENTRAL FCST AREA...RAP
RUC SNDGS FOR KIMT SUGGESTS CAP ALOFT MAY ERODE JUST ENOUGH TO ALLOW
FOR SOME ISOLD TO SCT SHRA/TSRA TO FORM TOWARD SUNSET OVER CNTRL
FCST AREA. INCREASING 800-700 MB FGEN IN RESPONSE TO RIGHT ENTRANCE
REGION FORCING IN 140+ KT 3H JET OVER NRN PLAINS AND WRN ONTARIO
WILL BE MAIN DRIVING FORCE FOR BAND OF RAIN WHICH MODELS PROJECT TO
FORM LATE THIS EVENING AND EARLY OVERNIGHT OVER CENTRAL PORTION OF
THE FCST AREA. THIS BAND OF PCPN IS THEN PROGGED BY MODELS TO SHIFT
OVER THE WRN CWA LATE TONIGHT INTO WED AS BEST FGEN FORCING SHIFTS
WEST. LOWS TONIGHT WILL BE IN THE 40S UNDER MOSTLY CLOUDY SKIES.
MODEL AVG QPF INDICATES THAT PORTIONS OF GOGEBIC AND ONTONAGON
COUNTIES COULD SEE UP TO QUARTER INCH OF PCPN LATE TONIGHT INTO
WEDNESDAY. COLDER AIR (8H TEMPS DROPPING BLO 0C )SEEPING INTO THE
WRN CWA COULD CAUSE SOME SNOW TO MIX IN WITH RAIN BY LATE WED
AFTERNOON AS TEMPS FALL INTO THE MID TO UPPER 30S TOWARD EVENING.
N-NW ONSHORE FLOW OFF COOL LAKE SUPERIOR ALONG CLOUDY SKIES WILL
RESULT IN MAX TEMPS ON THE LOWER END OF MODEL GUIDANCE FOR WEDNESDAY
WITH HIGHS RANGING FROM THE LOWER TO MID 40S ALONG LAKE SUPERIOR TO
GENERALLY THE LOWER TO MID 50S EAST AND SCNTRL.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 432 PM EDT TUE APR 30 2013
FORECAST CONTINUES TO DEAL WITH THE UPPER TROUGH DEVELOPING IN THE
IN THE NORTHERN PLAINS AND WHAT HAPPENS TO IT AS IT CUTS OFF AROUND
THE END OF THIS WEEK AND DRIFTS THIS WEEKEND.
TO START THE PERIOD...THE FORECAST CONCERN IS THE STALLED 850MB
FRONT STRETCHING FROM NORTHERN LAKE SUPERIOR THROUGH SOUTHEAST
MINNESOTA AND INTO THE CENTRAL PLAINS AS THE UPPER TROUGH SLOWLY
SHIFTS EAST THROUGH THE NORTHERN PLAINS. THE POSITION OF THE FRONT
WILL BE THE MAIN CONCERN...AS THERE WILL LIKELY BE AN AXIS OF HIGHER
PRECIPITATION AMOUNTS ALONG THIS FRONT. LATEST TRENDS IN THE MODELS
IS THAT THE 850MB FRONT IS A LITTLE FARTHER WEST AND THE HEAVIEST
PRECIPITATION LOOKS TO FALL SOMEWHERE EAST OF DULUTH AND WEST OF A
LINE FROM BARAGA TO WATERSMEET. WITH THE AREA THE 850-700MB WAA/FGEN
IS LINING UP...WOULD THINK THAT THE BEST PRECIPITATION WOULD BE OVER
THE FAR WESTERN CWA...BUT STILL EXPECT LIGHTER VALUES OVER THE REST
OF THE WESTERN CWA. THIS MATCHES UP WELL WITH THE 09Z SREF QPF
PROBABILITIES. THERE WILL PROBABLY BE SOME SHOWERS OVER THE
CENTRAL U.P. BUT THE AMOUNTS SHOULD BE LIGHTER THAN SEEN OVER THE
WEST. UNFORTUNATELY...THIS PRECIPITATION WON/T HELP THE ALREADY
SWOLLEN RIVERS AND STREAMS OVER FAR WESTERN UPPER MICHIGAN AND WILL
HEIGHTEN THE AFFECTS IN THE HWO AND INDIVIDUAL RIVER PRODUCTS.
BASED OFF THE THERMAL FIELDS AND BUFKIT SOUNDINGS...IT APPEARS THAT
IT WILL MAINLY BE SNOW OVER THE FAR WESTERN CWA...WITH A RAIN/SNOW
MIX OVER THE WEST-CENTRAL...BEFORE CHANGING TO ALL RAIN EAST OF A
LINE FROM NEGAUNEE TO CRYSTAL FALLS. THERE STILL REMAINS SOME
UNCERTAINTY IN THE P-TYPE TYPE AS THEY HAVE BEEN VARYING IN HOW FAR
WEST THE WARM AIR ALOFT SLIDES. NAM AND OUR REGIONAL WRF-ARW DO HINT
AT A SOME DRYING ALOFT WHICH COULD LIMIT ICE CRYSTAL POTENTIAL OVER
THE WEST...WHICH WILL BE SOMETHING TO WATCH. IF THE PRECIP STAYS AS
SNOW OVER THE WEST HALF OF GOGEBIC AND WESTERN ONTONAGON
COUNTY...THEY COULD SEE SIGNIFICANT LATE SEASON
SNOWFALL...ESPECIALLY ON THE COLDER SURFACES AND HIGHER TERRAIN.
CURRENTLY HAVE BORDERLINE WARNING SNOW AMOUNTS FOR WEDNESDAY NIGHT
INTO THURSDAY MORNING...SO WILL CONTINUE TO MENTION IN THE HWO. IF
CONFIDENCE WAS A LITTLE GREATER ON EXACT LOCATION OF THE HEAVIEST
QPF...AND THERE WEREN/T SEVERAL OTHER FLOOD WARNING/WATCH/ADVISORY
PRODUCTS OUT FOR GOGEBIC COUNTY...COULD HAVE ISSUED A WINTER
STORM WATCH.
THE UPPER TROUGH STARTS THE CUTOFF PROCESS THURSDAY NIGHT INTO
FRIDAY MORNING...WHICH WILL ALLOW THE FLOW ALOFT TO BECOME MORE
SOUTHEASTERLY AND SHIFT THE FRONT WEST. THIS WILL PULL WARMER AIR
INTO THE AREA AND SHOULD LIMIT THE SNOW POTENTIAL. BUT THIS WARMER
AIR MOVING IN ALOFT WILL LEAD COLD AIR TRAPPED NEAR THE SURFACE.
THIS HAS BEEN HINTED AT OVER THE LAST DAY...BUT HAVE CONCERNS THAT
THE GROUND TEMPERATURES WON/T GO BELOW FREEZING. THUS...WILL JUST
HAVE A SLIGHT CHANCE MENTION FOR AREAS WITH RAIN AND TEMPS BELOW 31
DEGREES. WITH THE DIFFERENCES IN THE HANDLING OF THE TROUGH CUTTING
OFF...THERE ARE DIFFERENCES IN THE MOVEMENT OF THE FRONT...SO WILL
GO WITH A BROADER POPS HEADING INTO FRIDAY...BUT THE BEST FOCUS
OVER THE SOUTHWEST HALF.
THE WEEKEND INTO EARLY NEXT WEEK STILL REMAINS UP IN THE AIR DUE TO
THE DIFFERENCES IN THE LOCATION OF THE UPPER LOW. 00Z ECMWF IS
CONSISTENT WITH IT/S PREVIOUS RUN AND IS FARTHEST TO THE NORTH. 12Z
GFS CONTINUES IT/S TREND OF BEING WELL TO THE SOUTH OF THE AREA
/CENTRAL MISSISSIPPI VALLEY/...WHILE THE 12Z GEM HAS IT IN THE
GREAT LAKES. AS WITH YESTERDAY...WILL FOLLOW A GENERAL CONSENSUS
INTO NEXT WEEK AS THE LOCATION OF THE LOW HAS LARGE IMPLICATIONS ON
TEMPERATURES AND PRECIPITATION.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 745 PM EDT TUE APR 30 2013
A COLD FRONT WILL PUSH THROUGH ALL THREE TAF SITES OVERNIGHT. WITH
DRIER AIR IN PLACE...PRECIPITATION WILL HOLD OFF UNTIL BETTER UPPER
LEVEL SUPPORT ARRIVES LATER TONIGHT OVER THE FAR WEST. THIS
DISTURBANCE WILL BRING A CHANCE FOR SHOWERS OVER THE FAR WEST TAF
SITES OVERNIGHT. KSAW MAY SEE A SHOWER OR TWO AFTER MIDNIGHT WITH
THE PASSAGE OF THE FRONT AS SLIGHTLY HIGHER DEWPOINTS EXIST THERE
DUE TO FLOW OFF OF LAKE MICHIGAN...BUT CONFIDENCE IN THIS IS NOT
HIGH.
WIND SHIFT AND INCREASING MOISTURE ADVECTION WILL PRODUCE LOWER CIGS
AND INCREASING CHANCES OF PRECIPITATION DURING THE DAY WITH LIFR
CIGS POSSIBLE AT KIWD AND IFR CIGS AT KCMX ON WEDNESDAY. KSAW WILL
REMAIN AT LOW END OF VFR FOR CIGS THROUGHOUT THE FORECAST UNTIL
POSSIBLY NEAR 0Z. RAIN MAY MIX WITH SNOW AT THE END OF THE FORECAST
PERIOD AT KIWD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 432 PM EDT TUE APR 30 2013
NO GALES SEEN IN THIS FORECAST PERIOD. WINDS WILL GET UP TO 30 KNOTS
ACROSS THE EASTERN PORTION OF LAKE SUPERIOR EARLY THIS EVENING WITH
TIGHTENING GRAD AHEAD OF COLD FRONT. WINDS THEN STAY GEENRALLY AT OR
BELOW 25 KNOTS FOR THE REST OF THE PERIOD.
&&
.HYDROLOGY...
ISSUED AT 432 PM EDT TUE APR 30 2013
ANOTHER DAY OF WARM TEMPERATURES HAS CONTINUED THE SNOW MELT AND
THE RISING RIVER LEVELS ACROSS THE AREA. FORTUNATELY...RAINFALL
AMOUNTS OVER THE LAST COUPLE OF DAYS HAVE BEEN FAIRLY LIGHT AND HAS
KEPT THE FLOODING CONCERNS TO THE SNOW MELT. THE MAIN SNOW LEFT
OVER THE AREA IS OVER THE HIGHER TERRAIN LOCATIONS OVER THE
WEST...WHERE VALUES ARE IN THE 3-15 INCH RANGE. THE WARM
TEMPERATURES TONIGHT SHOULD CONTINUE THE MELT...BUT IS SHOULD BE
SLOWED AS TEMPERATURES FALL BEHIND A COLD FRONT THAT MOVES
THROUGH TONIGHT. THIS FRONT WILL PRODUCE ISOLATED/SCATTERED SHOWERS
BUT WIDESPREAD MODERATE-HEAVY RAINFALL AMOUNTS ARE NOT EXPECTED.
ATTENTION THEN TURNS TO AN UPPER LEVEL FRONT THAT STALLS OVER FAR
WESTERN UPPER MICHIGAN WEDNESDAY THROUGH THURSDAY. THIS HAS THE
POTENTIAL TO PRODUCE OVER AN INCH OF QPF OVER THE WESTERN THIRD OF
UPPER MICHIGAN THROUGH THURSDAY NIGHT. THE HEAVIEST
AMOUNTS...POTENTIALLY EXCEEDING 1.5 INCHES WILL BE OVER WESTERN
ONTONAGON AND WESTERN GOGEBIC COUNTIES. WITH THE COLDER
TEMPERATURES...THERE IS UNCERTAINTY IN THE THE EXACT PRECIPITATION
TYPE...BUT IT LOOKS LIKE A RAIN/SNOW MIX OVER THE WEST AND MAINLY
SNOW OVER THE FAR WEST. THIS PRECIPITATION WILL NOT HELP MATTERS
OVER THE WESTERN CWA...WHERE MANY RIVERS/STREAMS/CREEKS ARE
EXCEEDING BANKFULL OR FLOODING. THIS PRECIPITATION WILL DEFINITELY
NEED TO BE WATCHED OVER THE NEXT DAY OR TWO TO PIN DOWN AMOUNTS AND
TYPES...WHICH WILL HELP DETERMINE THE TIME THEY WILL INFLUENCE THE
RIVERS. ELSEWHERE...THE TIME LAGGED FLOW INCREASES FROM THE SNOW
MELT WILL LEAD TO CONTINUED RISES OVER THE NORTH CENTRAL
TRIBUTARIES OF THE ESCANABA AND MICHIGAMME RIVERS. THESE AREAS MAY
SEE FLOODING OVER THE COMING DAYS.
IN THE NEAR TERM...THE GREATEST FLOODING THREAT IS FOR THE RIVERS
IN WEST AND CENTRAL UPPER MICHIGAN. SEVERAL RIVER FLOOD
WARNING/WATCH/ADVISORIES ARE ALREADY IN PLACE...ALONG WITH SOME
AERIAL FLOOD ADVISORIES. FOR COMPLETE DETAILS...SEE THE LATEST RIVER
FLOOD WATCHES...WARNINGS AND ADVISORIES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
FLASH FLOOD WATCH UNTIL 10 PM CDT THIS EVENING FOR MIZ009.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...SRF
AVIATION...RJT
MARINE...VOSS
HYDROLOGY...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
233 PM EDT MON APR 29 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 518 AM EDT MON APR 29 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A STRONG 160 KNOT 250-300 MB
JET MOVING INTO THE PAC NW AND A MAINLY ZONAL FLOW DOWNSTREAM TO THE
NRN GREAT LAKES. AT THE SFC...A COLD FRONT EXTENDED FROM LOW PRES
OVER HUDSON BAY TO NEAR JAMES BAY AND THROUGH WRN UPPER MI INTO NW
IA. THE COMBINATION OF LOW LEVEL CONV NEAR THE FRONT AND A WEAK
SHRTWV INTO UPPER SUPPORTED AN AREA OF LIGHT SHOWERS ACROSS CNTRL
UPPER MI INTO ERN LAKE SUPERIOR. HIGH PRES FROM THE NRN PLAINS WAS
BUILDING TOWARD THE REGION BRINGING IN DRIER AIR ALONG WITH CLEARING
SKIES FROM NRN MN INTO WRN LAKE SUPERIOR AND WRN UPPER MI. WITH SOME
LEFTOVER LOW LEVEL MOISTURE FROM THE LIGHT RAIN AND MELTING SNOW
ALONG WITH RADIATIONAL COOLING...SOME FOG HAD DEVELOPED FROM IWD TO
CMX.
RADAR/SATELLITE TRENDS SUGGEST THAT THE AREA OF SHOWERS WILL MOVE
THROUGH THE REST OF THE ERN HALF OF THE CWA THIS MORNING AS THE
FRONT GRADUALLY WEAKENS OVER SRN UPPER MI. AS ANOTHER WEAK SHORTWAVE
OVER SOUTH DAKOTA MOVES TOWARD THE AREA LATE THIS AFTERNOON AND
EVENING...MODELS SUGGEST THAT PCPN WILL AGAIN DEVELOP AND LIFT TO
THE NORTHEAST. HOWEVER...THERE REMAINS SOME UNCERTAINTY WITH THE
TIMING OF THE PCPN DEVELOPMENT AND MOVEMENT AND ON HOW FAR TO THE
NORTH INTO CNTRL UPPER MI THE PCPN WILL EXPAND. SO...ONLY CHANCE
POPS WERE INCLUDED FOR NOW. INSTABILITY TO SUPPORT TSRA...PER MDLS
MUCAPE...IS EXPECTED TO REMAIN SOUTH OF THE AREA.
FARTHER TO THE NORTHWEST...DRY CONDITIONS WILL PREVAIL WITH A
SUNSHINE AND WARM CONDITIONS. WITH 850 MB TEMPS AROUND 8C...TEMPS
SHOULD AGAIN CLIMB INTO THE MID 60S. READINGS IN THE UPPER 50S AND
LOWER 60S AND EXPECTED WHERE GREATER CLOUD COVER PREVAILS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 518 AM EDT MON APR 29 2013
EXTENDED FORECAST BECOMES MORE COMPLEX WITH ADDITION OF
THUNDERSTORMS /SOME ON THE STRONGER SIDE/ TUE AND TUE NIGHT AND SNOW
WED NIGHT INTO FRI. WILL FOCUS ON THESE TWO TIME FRAMES DUE TO MORE
BENIGN WEATHER AT THESE TIMES AND HELPING MANAGE EXTRA WORKLOAD ON
MORE IMPACTFUL HYDROLOGIC ISSUES.
FOR TUE...STARTING 12Z TUE THERE IS WILL BE AN UPPER SHORTWAVE
TROUGH OVER ND...WITH THE ASSOCIATED 995MB SFC LOW OVER NRN MN. THE
SYSTEM WILL MOVE TO HUDSON BAY BY 12Z WED WHILE DRAGGING A COLD
FRONT ACROSS THE CWA. THE COLD FRONT WILL ENCOUNTER VERY WARM LOW
LEVEL TEMPS AS 850MB TEMPS WILL BE AROUND 15C RESULTING IN HIGHS IN
THE 60S AND 70S. THUNDERSTORMS CERTAINLY APPEAR POSSIBLE...WITH EVEN
UP TO AROUND 1000 J/KG OF MUCAPE OVER THE REGION. THANKFULLY...SHEAR
WILL BE WEAK WHICH WILL FURTHER LIMIT SEVERE POTENTIAL. THERE COULD
BE SOME STRONGER STORMS...BUT NO SEVERE WEATHER IS EXPECTED AT THIS
TIME. DO SEE THE FRONT MOVE INTO WRN UPPER MI AROUND 00Z
WED...MOVING TO THE ERN U.P. BY 12Z WED. COULD ALSO SEE SOME HEAVY
RAINFALL...WHICH WILL NOT HELP HYDROLOGIC SITUATION DUE TO SNOWMELT
OVER THE CWA.
AFTER THE SYSTEM MOVES AWAY FROM THE AREA...THE CWA WILL BE SQUEEZED
BETWEEN A DEEPENING UPPER TROUGH JUST W OF THE CWA AND A
STRENGTHENING UPPER RIDGE JUST E OF THE CWA. AN 850MB TROUGH WILL BE
ANCHORED OVER THE CWA. ALL THIS WILL HAPPEN WED AND THU...BEFORE THE
UPPER TROUGH CLOSES OFF OVER MY BY FRI AS THE UPPER RIDGE GETS CUT
OFF AND MOVES INTO THE CWA FROM THE E. FGEN PRECIP ON THE NW SIDE OF
THE 850MB TROUGH WILL LEAD TO THE POSSIBILITY OF SIGNIFICANT PRECIP
OVER THE CENTRAL/WESTERN CWA WED NIGHT INTO FRI...MUCH OF WHICH MAY
BE SNOW OVER THE FARTHER W ZONES. THERE REMAINS A GOOD AMOUNT OF
UNCERTAINTY...BUT HEADLINE WORTHY SNOW DOES LOOK POSSIBLE OVER THE
WRN CWA. WITH AFOREMENTIONED HYDRO CONCERNS...WILL HAVE TO CONTINUE
TO CLOSELY LOOK AT PTYPE/AMOUNTS AS THE WEEK PROGRESSES.
WARMER TEMPS LOOK TO RETURN ON FRI AS 850MB TEMPS INCREASE UP TO
9C...WARMEST E. FOR NEXT WEEKEND...UNCERTAINTY INCREASES
SIGNIFICANTLY...SO WILL JUST USE A CONSENSUS OF MODEL GUIDANCE FOR
THIS PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 231 PM EDT MON APR 29 2013
VFR CEILINGS AND VIS WILL LIKELY FALL THIS EVENING UNDER FOG...GIVEN
HIGH LEVELS OF LOW LEVEL MOISTURE AND INCREASED SOUTHERLY FLOW. LOOK
FOR FOG TO SLOWLY WEAKEN DURING THE DAY TUESDAY AS STRONGER
SOUTHERLY WINDS TAKE HOLD...WITH GUSTS OF 20-25KTS FROM LATE MORNING
ON. THE STRONGEST WINDS WILL BE LIKELY AT IWD AND SAW THROUGH THE
DAY.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 518 AM EDT MON APR 29 2013
WINDS SHOULD STAY BELOW 25KT THROUGH THE PERIOD WITH NO GALES
EXPECTED. NO STRONG SYSTEMS WILL BE COMING CLOSE TO THE AREA...SO NO
STRONG PRESSURE GRADIENTS ARE EXPECTED.
&&
.HYDROLOGY...
ISSUED AT 518 AM EDT MON APR 29 2013
YESTERDAY SAW TEMPS IN THE 60S AND 70S...FOLLOWED BY LOWS LAST NIGHT
IN THE 40S...WHICH HAS KEPT THE MELTING GOING ACROSS THE CWA. SNOW
DEPTHS HAVE FALLEN 15-20 INCHES IN THE LAST WEEK. THE MOST SNOW
REMAINS ON THE GROUND ACROSS NORTHERN UPPER MICHIGAN IN THE INLAND
AND HIGHER TERRAIN AREAS. STILL HAVE TO MELT ANOTHER 12-20 INCHES OF
SNOW IN SOME OF THESE AREAS. TROUGH MOVING THROUGH TONIGHT INTO
TODAY IS DROPPING GENERALLY AROUND 0.25 INCHES OF RAIN...BUT IN SOME
CASES UP TO .5 INCHES HAS FALLEN. ADDITIONAL RAIN WITH POSSIBLE
THUNDERSTORMS MAY OCCUR TUESDAY INTO TUESDAY NIGHT AS A COLD FRONT
WORKS ACROSS UPPER MICHIGAN. HIGHER MOISTURE OVER THE AREA MAY RESULT
IN HEAVY DOWNPOURS WITH ANY THUNDERSTORMS. MUCH COOLER TEMPERATURES
EXPECTED FOR REST OF WEEK BEHIND THE FRONT. ADDITIONAL CHANCES OF
RAIN AND EVEN SNOW WILL ALSO CONTINUE ACROSS UPPER MICHIGAN FOR THE
REST OF THE WEEK. SO...EVEN THOUGH TEMPERATURES WILL BE COOLER THIS
MAY BE OFFSET BY THE ADDITIONAL PRECIPITATION THAT MAY OCCUR.
RIVERS OF PARTICULAR CONCERN DUE TO MELTING WILL BE THE TRAP ROCK
RIVER...THE STURGEON RIVER OF BARAGA/HOUGHTON COUNTIES...THE
PESHEKEE RIVER...THE PAINT RIVER NEAR CRYSTAL FALLS...THE ONTONAGON
RIVER AT EWEN AND EVENTUALLY THE MICHIGAMME RIVER NEAR REPUBLIC AND
WITCH LAKE. MELTING SCENARIOS STILL REMAIN THE BIGGEST CONFIDENCE
REDUCERS IN RIVER FORECASTS FOR THE PESHEKEE AND MICHIGAMME BASINS
WHERE MOST OF THE MELTING HAS NOT HIT ANY OBSERVED RIVER POINTS
YET...ALTHOUGH READINGS WILL BE GATHERED FROM THE PESHEKEE RIVER AND
LAKE MICHIGAMME THIS MORNING BY NWS PERSONNEL WHICH SHOULD HELP GET
A BETTER IDEA OF MELTING CONDITIONS INTO THE BASIN. AT OTHER
LOCATIONS...SUFFICIENT RUNOFF FROM MELTING HAS BEEN OBSERVED TO MORE
ACCURATELY GET A HANDLE OF MELT RATES FOR THE RIVER MODELS. NWS
SURVEY OF THE PESHEKEE RIVER ON SATURDAY REVEALED THICK ICE COVERING
MOST OF THE RIVER NEAR AND DOWNSTREAM OF THE CHPM4 RIVER GAUGING
LOCATION /AUTOMATED GAUGE DISCONTINUED BUT OBS ARE BEING TAKEN USING
A WIRE WEIGHT GAUGE AT THE LOCATION/ AND THICK ICE COVER ON MOST OF
LAKE MICHIGAMME WHICH THE PESHEKEE DRAINS INTO. ICE JAMS MAY CAUSE
SIGNIFICANT PROBLEMS AS THE RIVER RISES THROUGH MONDAY. MAIN STEM
RIVERS ARE NOT THE ONLY HAZARD...AS THERE IS ALSO A THREAT OF AREAL
FLOOD PROBLEMS WITH SMALLER CREEKS/STREAMS AND STANDING WATER ON
ROADS. HAVE RECEIVED SOME SPORADIC REPORTS OF AREAL TYPE
FLOODING...BUT NOT ENOUGH SIGNIFICANT REPORTS FOR HAZARD ISSUANCE.
FOR COMPLETE DETAILS...SEE THE HYDROLOGIC OUTLOOK /ESF/ AND THE
LATEST RIVER FLOOD WATCHES...WARNINGS AND ADVISORIES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...KF
MARINE...JLB
HYDROLOGY...TITUS
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
139 PM EDT MON APR 29 2013
.SYNOPSIS...
ISSUED AT 344 AM EDT MON APR 29 2013
AREAS OF FOG WILL BE FOUND EARLY THIS MORNING...ESPECIALLY ACROSS
AREAS NEAR AND SOUTH OF I-69. ONCE THE FOG DISSIPATES...MOST AREAS
SHOULD WARM UP NICELY TO AROUND 70 WITH A DECENT AMOUNT OF SUNSHINE.
THERE WILL BE A CHANCE OF SHOWERS UP NORTH THIS AFTERNOON.
A CHANCE OF SHOWERS AND STORMS WILL EXIST TONIGHT AND INTO TUESDAY
AS A WAVE OF LOW PRESSURE AND A SURGE OF WARMER AND MORE MOIST AIR
MOVES TOWARD THE AREA.
A FRONT EXPECTED TO NEARLY STALL OUT TO OUR WEST TUESDAY AND
WEDNESDAY WILL TRY TO LEAN INTO THE AREA ON THURSDAY AND INCREASE
THE CHANCE FOR SHOWERS AND STORMS. MUCH OF THE AREA COULD SEE THEIR
FIRST 80 DEGREE TEMPERATURE OF THIS SPRING ON TUESDAY AND/OR
WEDNESDAY.
&&
.UPDATE...
ISSUED AT 1202 PM EDT MON APR 29 2013
SHORTWAVE TROUGH IS PUSHING FROM MINNESOTA INTO WISCONSIN AT
MIDDAY WITH A SURFACE COLD FRONT LOCATED AHEAD OF IT STRETCHING
FROM WISCONSIN SOUTHWEST INTO IOWA. A BAND OF SHOWERS AND A FEW
EMBEDDED THUNDERSTORMS WERE LOCATED NEAR THE FRONT.
HI-RES WRF MODELS (NSSL AND SPC) AND THE HRRR KEEP THE BULK OF THE
PRECIPITATION TO THE NORTH AND WEST OF THE FORECAST AREA THIS
AFTERNOON. SOME SCATTERED SHOWER ACTIVITY IS POSSIBLE ACROSS ABOUT
THE NORTHERN THIRD OF THE FORECAST AREA AND HAVE MAINTAINED POPS
IN THE FORECAST UP THERE. THROUGH THE AFTERNOON...THE BEST
MOISTURE RETURN AND LIFT SHOULD BE WEST AND NORTH OF THE FORECAST
AREA. THE UPSTREAM SURFACE COLD FRONT ACTUALLY WASHES OUT WITH
TIME OVER ABOUT THE NEXT 18 HOURS AS NEW MID LEVEL ENERGY TAKES
OVER FROM THE WEST.
THE SHOWER AND POSSIBLY SOME THUNDERSTORM ACTIVITY DOES TRY TO
SPILL INTO THE CWA THIS EVENING AND TONIGHT. IT APPEARS THE
NORTHERN CWA MAY SEE PRECIPITATION THIS EVENING...SPREADING INTO
WESTERN PORTIONS OF THE FORECAST OVERNIGHT.
HIGH TEMPERATURES WILL MAKE A RUN INTO THE LOWER TO MIDDLE 70S AT
MOST LOCATIONS WITH COOLER READINGS NEAR LAKE MICHIGAN.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 344 AM EDT MON APR 29 2013
FORECAST CONCERNS WITH THE SHORT TERM INCLUDE FOG ISSUES THIS
MORNING AND PCPN TRENDS THROUGH THE PERIOD.
WE HAVE ISSUED A DENSE FOG ADVISORY FOR THE SE CORNER OF THE CWFA
FOR THIS MORNING. OBS AT KJXN...KTEW...KRMY...AND EVEN AT KLAN ARE
ALL AT OR HAVE BEEN AT 1/4SM EARLY THIS MORNING. THESE LOCATIONS
HAVE SEEN THE WORST CONDITIONS AS A RESULT OF THE BETTER RAINFALL
THAT OCCURRED ON SUNDAY. THE WORST VISIBILITIES SEEM TO ALIGN VERY
WELL WITH THE PLACES THAT SAW THE MOST RAIN PER THE KGRR STORM TOTAL
PCPN PRODUCT. WE HAVE KALAMAZOO COUNTY AND EATON COUNTY IN THE
ADVISORY EVEN THOUGH NO OBS OFFICIALLY SUPPORT FOG YET. DUE TO THE
RAINFALL PLACEMENT ON SUN...WE THINK THERE IS A GOOD CHANCE
LOCATIONS IN THESE COUNTIES ARE SEEING ENOUGH FOG TO JUSTIFY THE
ADVISORY THERE.
AS FAR AS PCPN TRENDS ARE CONCERNED...WE HAVE GENERALLY TRENDED THE
CHCS LOWER JUST A LITTLE THROUGH WED AS IT SEEMS LIKE THE FRONT WILL
GET HELD UP A LITTLE FURTHER WEST THAN PREVIOUSLY INDICATED. WE
BELIEVE THIS IS THE CASE SINCE THE MAIN TROUGH THAT FORMS THE UPPER
LOW DIGS A LITTLE FURTHER SOUTH AND WEST...HELPING TO BUILD THE
RIDGE CLOSER TO MI.
WE WILL SEE THE INITIAL FRONT NOW MAKING ITS WAY PAST KMSP AND INTO
WI. THIS FRONT IS EXPECTED TO STALL OUT SOON AS IT ALIGNS WITH THE
MID LEVEL FLOW. THE CONVECTION WITH IT SHOULD STAY CLOSE TO IT...AND
CLOUD SNEAK INTO THE NW CORNER OF THE CWFA LATER TODAY. WE BELIEVE
THAT MOST OF IT SHOULD REMAIN NW OF THE CWFA. THE FRONT WILL
GRADUALLY WASH OUT TONIGHT.
WE WILL SEE A SURGE OF WARM AND MOIST AIR ALOFT TONIGHT AND EARLY
TUE AS A 35-40 KNOT LLJ WILL TRANSLATE NE ACROSS WI AND NRN LOWER
MI. MOST OF THE MODELS KEEP THE CONVECTION JUST TO OUR NW ONCE
AGAIN. THE OUTLIER IS THE TRUSTY EURO WHICH DEVELOPS PCPN OVER THE
NRN 2/3RDS OF THE CWFA AT THE LEADING EDGE OF THE WARM/MOIST SURGE.
THERE HAVE BEEN MANY TIMES THE EURO IS THE OUTLIER WITH A PCPN EVENT
LIKE THIS...AND HAS BEEN CORRECT. WE HAVE MAINTAINED SMALL CHCS OF
SHOWERS AND STORMS TONIGHT AND INTO TUE TO ACCOUNT FOR THAT. WE
SHOULD SEE SUNSHINE BREAK OUT TUE AFTERNOON AND MIX INTO H850 TEMPS
IN THE MID TEENS C. THIS WILL SUPPORT SOME POTENTIAL 80 DEGREE
READINGS TUE AFTERNOON.
ONCE THAT SURGE MOVES N AND E OF THE CWFA...WE SHOULD GENERALLY DRY
OUT FOR THE REMAINDER OF THE SHORT TERM THROUGH WED. THE FRONT WILL
LIKELY LINE UP ALONG THE NW MI COAST ALONG LAKE MICHIGAN. ALL OF THE
PCPN WILL BE ON THE COOL SIDE OF THE FRONT WITH THE WARMER AIR
OVERRIDING THE FRONT. H850 TEMPS REMAIN UP IN THE MID TEENS C...SO
80 DEGREES LOOKS ATTAINABLE ONCE AGAIN DURING THE DAY ON WED.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 344 AM EDT MON APR 29 2013
LONG RANGE MODELS CONTINUE TO HAVE VERY POOR RUN TO RUN CONSISTENCY
WITH THE BLOCKING PATTERN ACROSS THE EASTERN CONUS THIS WEEK. HAVE
BEEN FORCED TO INCLUDE LOW CHANCE OR SLIGHT POPS ALMOST ALL PERIODS
ALTHOUGH IT IS POSSIBLE THAT MOST PERIODS WILL REMAIN DRY.
00Z GFS AND EURO SHOW THE BEST CHANCE FOR RAIN WILL BE ACROSS THE
WESTERN FORECAST AREA THURSDAY INTO FRIDAY AS THE UPPER TROUGH
APPROACHES. THEN IT STALLS AS THE SOUTHERN END OF THE TROUGH CUTS
OFF SPINS SOMEWHERE OVER THE PLAINS.
A NEW WRINKLE WITH THE 00Z EURO IS THAT THE UPPER LOW LIFTS NORTH
AND MISSES THE GREAT LAKES AS UPPER TROUGHING MOVES INTO WESTERN
CANADA. THIS IS A DEPARTURE FROM MOST OF THE PAST RUNS...SO WILL NOT
GIVE IT MUCH WEIGHT FOR NOW. WILL GO MORE WITH THE GFS IDEA OF
BRINGING THE UPPER LOW IN BY SUNDAY...ALTHOUGH THIS HAS TRENDED
SLOWER AND COULD BE DELAYED UNTIL MONDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 139 PM EDT MON APR 29 2013
ADDED THE CHANCE FOR AN ISOLATED THUNDERSTORM AT THE INLAND TAF
SITES FOR THIS EVENING. AN UPPER LEVEL DISTURBANCE WILL CROSS THE
REGION IN THIS TIME FRAME ALONG WITH BUILDING INSTABILITY.
THE SOUTHERN FLOW WILL INCREASE AROUND SUNRISE TUESDAY...REACHING
NEAR 20 KTS TOWARD MID DAY.
&&
.MARINE...
ISSUED AT 344 AM EDT MON APR 29 2013
WE ARE GOING TO ISSUE A SMALL CRAFT ADVISORY FOR THE NEARSHORE
WATERS WITH THIS FCST PACKAGE. WINDS WILL INCREASE TONIGHT AS THE
BETTER PRESSURE GRADIENT MOVES IN ACROSS THE AREA. THIS WILL REMAIN
IN PLACE GENERALLY UNTIL THE MORNING HOURS ON WED BEFORE IT SHIFTS
WEST OF THE AREA WITH THE FRONT.
&&
.FIRE WEATHER...
ISSUED AT 344 AM EDT MON APR 29 2013
A SLIGHTLY ELEVATED FIRE DANGER WILL EXIST OVER THE NEXT FEW DAYS AS
TEMPS WARM UP QUITE A BIT AND WE STILL HAVE A WAYS TO GO BEFORE
GREEN UP OCCURS EVERYWHERE. WINDS WILL PICK UP A BIT...ESPECIALLY ON
TUE WHEN THE BETTER GRADIENT WILL BE OVERHEAD. FORTUNATELY...RH
VALUES ARE NOT EXPECTED TO GET SIGNIFICANTLY LOW. WE HAVE NEAR 50
DEGREE DEW POINTS ALREADY ACROSS THE AREA. A SRLY FLOW WILL HELP
KEEP DEW POINTS UP...ALTHOUGH THEY COULD DROP A FEW DEGREES DURING
THE AFTERNOON HOURS DUE TO MIXING. WE ARE EXPECTING MIN RH VALUES IN
THE 35 TO 45 PCT RANGE IN GENERAL FOR THE NEXT FEW DAYS.
&&
.HYDROLOGY...
ISSUED AT 344 AM EDT MON APR 29 2013
NO ADDITIONAL HYDROLOGY PROBLEMS EXPECTED ON TOP OF THE RESIDUAL
FLOOD WARNINGS AND ADVISORIES THAT ARE ALREADY OUT FOR SOME OF THE
RIVER POINTS. WE HAVE A CHANCE OF SEEING RAIN ON AT LEAST A COUPLE
OF OCCASIONS THIS WEEK. THE RAINS DO NOT LOOK TO BE HEAVY NOR
WIDESPREAD OVER OUR AREA. AMOUNTS SHOULD GENERALLY STAY BELOW 0.50
INCHES. ADDITIONAL RAIN SHOWERS WILL REMAIN POSSIBLE INTO NEXT
WEEK...WITH NO SIGNIFICANT RAINS EXPECTED AT THIS TIME.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
WEDNESDAY FOR LMZ844>849.
&&
$$
UPDATE...DUKE
SYNOPSIS...NJJ
SHORT TERM...NJJ
LONG TERM...OSTUNO
AVIATION...JK
FIRE WEATHER...NJJ
HYDROLOGY...NJJ
MARINE...NJJ
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1203 PM EDT MON APR 29 2013
.SYNOPSIS...
ISSUED AT 344 AM EDT MON APR 29 2013
AREAS OF FOG WILL BE FOUND EARLY THIS MORNING...ESPECIALLY ACROSS
AREAS NEAR AND SOUTH OF I-69. ONCE THE FOG DISSIPATES...MOST AREAS
SHOULD WARM UP NICELY TO AROUND 70 WITH A DECENT AMOUNT OF SUNSHINE.
THERE WILL BE A CHANCE OF SHOWERS UP NORTH THIS AFTERNOON.
A CHANCE OF SHOWERS AND STORMS WILL EXIST TONIGHT AND INTO TUESDAY
AS A WAVE OF LOW PRESSURE AND A SURGE OF WARMER AND MORE MOIST AIR
MOVES TOWARD THE AREA.
A FRONT EXPECTED TO NEARLY STALL OUT TO OUR WEST TUESDAY AND
WEDNESDAY WILL TRY TO LEAN INTO THE AREA ON THURSDAY AND INCREASE
THE CHANCE FOR SHOWERS AND STORMS. MUCH OF THE AREA COULD SEE THEIR
FIRST 80 DEGREE TEMPERATURE OF THIS SPRING ON TUESDAY AND/OR
WEDNESDAY.
&&
.UPDATE...
ISSUED AT 1202 PM EDT MON APR 29 2013
SHORTWAVE TROUGH IS PUSHING FROM MINNESOTA INTO WISCONSIN AT
MIDDAY WITH A SURFACE COLD FRONT LOCATED AHEAD OF IT STRETCHING
FROM WISCONSIN SOUTHWEST INTO IOWA. A BAND OF SHOWERS AND A FEW
EMBEDDED THUNDERSTORMS WERE LOCATED NEAR THE FRONT.
HI-RES WRF MODELS (NSSL AND SPC) AND THE HRRR KEEP THE BULK OF THE
PRECIPITATION TO THE NORTH AND WEST OF THE FORECAST AREA THIS
AFTERNOON. SOME SCATTERED SHOWER ACTIVITY IS POSSIBLE ACROSS ABOUT
THE NORTHERN THIRD OF THE FORECAST AREA AND HAVE MAINTAINED POPS
IN THE FORECAST UP THERE. THROUGH THE AFTERNOON...THE BEST
MOISTURE RETURN AND LIFT SHOULD BE WEST AND NORTH OF THE FORECAST
AREA. THE UPSTREAM SURFACE COLD FRONT ACTUALLY WASHES OUT WITH
TIME OVER ABOUT THE NEXT 18 HOURS AS NEW MID LEVEL ENERGY TAKES
OVER FROM THE WEST.
THE SHOWER AND POSSIBLY SOME THUNDERSTORM ACTIVITY DOES TRY TO
SPILL INTO THE CWA THIS EVENING AND TONIGHT. IT APPEARS THE
NORTHERN CWA MAY SEE PRECIPITATION THIS EVENING...SPREADING INTO
WESTERN PORTIONS OF THE FORECAST OVERNIGHT.
HIGH TEMPERATURES WILL MAKE A RUN INTO THE LOWER TO MIDDLE 70S AT
MOST LOCATIONS WITH COOLER READINGS NEAR LAKE MICHIGAN.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 344 AM EDT MON APR 29 2013
FORECAST CONCERNS WITH THE SHORT TERM INCLUDE FOG ISSUES THIS
MORNING AND PCPN TRENDS THROUGH THE PERIOD.
WE HAVE ISSUED A DENSE FOG ADVISORY FOR THE SE CORNER OF THE CWFA
FOR THIS MORNING. OBS AT KJXN...KTEW...KRMY...AND EVEN AT KLAN ARE
ALL AT OR HAVE BEEN AT 1/4SM EARLY THIS MORNING. THESE LOCATIONS
HAVE SEEN THE WORST CONDITIONS AS A RESULT OF THE BETTER RAINFALL
THAT OCCURRED ON SUNDAY. THE WORST VISIBILITIES SEEM TO ALIGN VERY
WELL WITH THE PLACES THAT SAW THE MOST RAIN PER THE KGRR STORM TOTAL
PCPN PRODUCT. WE HAVE KALAMAZOO COUNTY AND EATON COUNTY IN THE
ADVISORY EVEN THOUGH NO OBS OFFICIALLY SUPPORT FOG YET. DUE TO THE
RAINFALL PLACEMENT ON SUN...WE THINK THERE IS A GOOD CHANCE
LOCATIONS IN THESE COUNTIES ARE SEEING ENOUGH FOG TO JUSTIFY THE
ADVISORY THERE.
AS FAR AS PCPN TRENDS ARE CONCERNED...WE HAVE GENERALLY TRENDED THE
CHCS LOWER JUST A LITTLE THROUGH WED AS IT SEEMS LIKE THE FRONT WILL
GET HELD UP A LITTLE FURTHER WEST THAN PREVIOUSLY INDICATED. WE
BELIEVE THIS IS THE CASE SINCE THE MAIN TROUGH THAT FORMS THE UPPER
LOW DIGS A LITTLE FURTHER SOUTH AND WEST...HELPING TO BUILD THE
RIDGE CLOSER TO MI.
WE WILL SEE THE INITIAL FRONT NOW MAKING ITS WAY PAST KMSP AND INTO
WI. THIS FRONT IS EXPECTED TO STALL OUT SOON AS IT ALIGNS WITH THE
MID LEVEL FLOW. THE CONVECTION WITH IT SHOULD STAY CLOSE TO IT...AND
CLOUD SNEAK INTO THE NW CORNER OF THE CWFA LATER TODAY. WE BELIEVE
THAT MOST OF IT SHOULD REMAIN NW OF THE CWFA. THE FRONT WILL
GRADUALLY WASH OUT TONIGHT.
WE WILL SEE A SURGE OF WARM AND MOIST AIR ALOFT TONIGHT AND EARLY
TUE AS A 35-40 KNOT LLJ WILL TRANSLATE NE ACROSS WI AND NRN LOWER
MI. MOST OF THE MODELS KEEP THE CONVECTION JUST TO OUR NW ONCE
AGAIN. THE OUTLIER IS THE TRUSTY EURO WHICH DEVELOPS PCPN OVER THE
NRN 2/3RDS OF THE CWFA AT THE LEADING EDGE OF THE WARM/MOIST SURGE.
THERE HAVE BEEN MANY TIMES THE EURO IS THE OUTLIER WITH A PCPN EVENT
LIKE THIS...AND HAS BEEN CORRECT. WE HAVE MAINTAINED SMALL CHCS OF
SHOWERS AND STORMS TONIGHT AND INTO TUE TO ACCOUNT FOR THAT. WE
SHOULD SEE SUNSHINE BREAK OUT TUE AFTERNOON AND MIX INTO H850 TEMPS
IN THE MID TEENS C. THIS WILL SUPPORT SOME POTENTIAL 80 DEGREE
READINGS TUE AFTERNOON.
ONCE THAT SURGE MOVES N AND E OF THE CWFA...WE SHOULD GENERALLY DRY
OUT FOR THE REMAINDER OF THE SHORT TERM THROUGH WED. THE FRONT WILL
LIKELY LINE UP ALONG THE NW MI COAST ALONG LAKE MICHIGAN. ALL OF THE
PCPN WILL BE ON THE COOL SIDE OF THE FRONT WITH THE WARMER AIR
OVERRIDING THE FRONT. H850 TEMPS REMAIN UP IN THE MID TEENS C...SO
80 DEGREES LOOKS ATTAINABLE ONCE AGAIN DURING THE DAY ON WED.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 344 AM EDT MON APR 29 2013
LONG RANGE MODELS CONTINUE TO HAVE VERY POOR RUN TO RUN CONSISTENCY
WITH THE BLOCKING PATTERN ACROSS THE EASTERN CONUS THIS WEEK. HAVE
BEEN FORCED TO INCLUDE LOW CHANCE OR SLIGHT POPS ALMOST ALL PERIODS
ALTHOUGH IT IS POSSIBLE THAT MOST PERIODS WILL REMAIN DRY.
00Z GFS AND EURO SHOW THE BEST CHANCE FOR RAIN WILL BE ACROSS THE
WESTERN FORECAST AREA THURSDAY INTO FRIDAY AS THE UPPER TROUGH
APPROACHES. THEN IT STALLS AS THE SOUTHERN END OF THE TROUGH CUTS
OFF SPINS SOMEWHERE OVER THE PLAINS.
A NEW WRINKLE WITH THE 00Z EURO IS THAT THE UPPER LOW LIFTS NORTH
AND MISSES THE GREAT LAKES AS UPPER TROUGHING MOVES INTO WESTERN
CANADA. THIS IS A DEPARTURE FROM MOST OF THE PAST RUNS...SO WILL NOT
GIVE IT MUCH WEIGHT FOR NOW. WILL GO MORE WITH THE GFS IDEA OF
BRINGING THE UPPER LOW IN BY SUNDAY...ALTHOUGH THIS HAS TRENDED
SLOWER AND COULD BE DELAYED UNTIL MONDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 748 AM EDT MON APR 29 2013
SOME PATCHY IFR FOG EARLY THIS MORNING WILL LIFT WITH VFR
CONDITIONS EXPECTED TODAY. SOUTH WINDS WILL BE AROUND 10 KNOTS.
SHOWERS AND SCATTERED THUNDERSTORMS ARE POSSIBLE LATER TONIGHT BUT
COVERAGE SHOULD BE LOW AND SO WERE LEFT OUT OF THE FORECAST FOR
NOW.
&&
.MARINE...
ISSUED AT 344 AM EDT MON APR 29 2013
WE ARE GOING TO ISSUE A SMALL CRAFT ADVISORY FOR THE NEARSHORE
WATERS WITH THIS FCST PACKAGE. WINDS WILL INCREASE TONIGHT AS THE
BETTER PRESSURE GRADIENT MOVES IN ACROSS THE AREA. THIS WILL REMAIN
IN PLACE GENERALLY UNTIL THE MORNING HOURS ON WED BEFORE IT SHIFTS
WEST OF THE AREA WITH THE FRONT.
&&
.FIRE WEATHER...
ISSUED AT 344 AM EDT MON APR 29 2013
A SLIGHTLY ELEVATED FIRE DANGER WILL EXIST OVER THE NEXT FEW DAYS AS
TEMPS WARM UP QUITE A BIT AND WE STILL HAVE A WAYS TO GO BEFORE
GREENUP OCCURS EVERYWHERE. WINDS WILL PICK UP A BIT...ESPECIALLY ON
TUE WHEN THE BETTER GRADIENT WILL BE OVERHEAD. FORTUNATELY...RH
VALUES ARE NOT EXPECTED TO GET SIGNIFICANTLY LOW. WE HAVE NEAR 50
DEGREE DEW POINTS ALREADY ACROSS THE AREA. A SRLY FLOW WILL HELP
KEEP DEW POINTS UP...ALTHOUGH THEY COULD DROP A FEW DEGREES DURING
THE AFTERNOON HOURS DUE TO MIXING. WE ARE EXPECTING MIN RH VALUES IN
THE 35 TO 45 PCT RANGE IN GENERAL FOR THE NEXT FEW DAYS.
&&
.HYDROLOGY...
ISSUED AT 344 AM EDT MON APR 29 2013
NO ADDITIONAL HYDROLOGY PROBLEMS EXPECTED ON TOP OF THE RESIDUAL
FLOOD WARNINGS AND ADVISORIES THAT ARE ALREADY OUT FOR SOME OF THE
RIVER POINTS. WE HAVE A CHANCE OF SEEING RAIN ON AT LEAST A COUPLE
OF OCCASIONS THIS WEEK. THE RAINS DO NOT LOOK TO BE HEAVY NOR
WIDESPREAD OVER OUR AREA. AMOUNTS SHOULD GENERALLY STAY BELOW 0.50
INCHES. ADDITIONAL RAIN SHOWERS WILL REMAIN POSSIBLE INTO NEXT
WEEK...WITH NO SIGNIFICANT RAINS EXPECTED AT THIS TIME.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
WEDNESDAY FOR LMZ844>849.
&&
$$
UPDATE...DUKE
SYNOPSIS...NJJ
SHORT TERM...NJJ
LONG TERM...OSTUNO
AVIATION...OSTUNO
FIRE WEATHER...NJJ
HYDROLOGY...NJJ
MARINE...NJJ
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
754 AM EDT MON APR 29 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 518 AM EDT MON APR 29 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A STRONG 160 KNOT 250-300 MB
JET MOVING INTO THE PAC NW AND A MAINLY ZONAL FLOW DOWNSTREAM TO THE
NRN GREAT LAKES. AT THE SFC...A COLD FRONT EXTENDED FROM LOW PRES
OVER HUDSON BAY TO NEAR JAMES BAY AND THROUGH WRN UPPER MI INTO NW
IA. THE COMBINATION OF LOW LEVEL CONV NEAR THE FRONT AND A WEAK
SHRTWV INTO UPPER SUPPORTED AN AREA OF LIGHT SHOWERS ACROSS CNTRL
UPPER MI INTO ERN LAKE SUPERIOR. HIGH PRES FROM THE NRN PLAINS WAS
BUILDING TOWARD THE REGION BRINGING IN DRIER AIR ALONG WITH CLEARING
SKIES FROM NRN MN INTO WRN LAKE SUPERIOR AND WRN UPPER MI. WITH SOME
LEFTOVER LOW LEVEL MOISTURE FROM THE LIGHT RAIN AND MELTING SNOW
ALONG WITH RADIATIONAL COOLING...SOME FOG HAD DEVELOPED FROM IWD TO
CMX.
RADAR/SATELLITE TRENDS SUGGEST THAT THE AREA OF SHOWERS WILL MOVE
THROUGH THE REST OF THE ERN HALF OF THE CWA THIS MORNING AS THE
FRONT GRADUALLY WEAKENS OVER SRN UPPER MI. AS ANOTHER WEAK SHORTWAVE
OVER SOUTH DAKOTA MOVES TOWARD THE AREA LATE THIS AFTERNOON AND
EVENING...MODELS SUGGEST THAT PCPN WILL AGAIN DEVELOP AND LIFT TO
THE NORTHEAST. HOWEVER...THERE REMAINS SOME UNCERTAINTY WITH THE
TIMING OF THE PCPN DEVELOPMENT AND MOVEMENT AND ON HOW FAR TO THE
NORTH INTO CNTRL UPPER MI THE PCPN WILL EXPAND. SO...ONLY CHANCE
POPS WERE INCLUDED FOR NOW. INSTABILITY TO SUPPORT TSRA...PER MDLS
MUCAPE...IS EXPECTED TO REMAIN SOUTH OF THE AREA.
FARTHER TO THE NORTHWEST...DRY CONDITIONS WILL PREVAIL WITH A
SUNSHINE AND WARM CONDITIONS. WITH 850 MB TEMPS AROUND 8C...TEMPS
SHOULD AGAIN CLIMB INTO THE MID 60S. READINGS IN THE UPPER 50S AND
LOWER 60S AND EXPECTED WHERE GREATER CLOUD COVER PREVAILS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 518 AM EDT MON APR 29 2013
EXTENDED FORECAST BECOMES MORE COMPLEX WITH ADDITION OF
THUNDERSTORMS /SOME ON THE STRONGER SIDE/ TUE AND TUE NIGHT AND SNOW
WED NIGHT INTO FRI. WILL FOCUS ON THESE TWO TIME FRAMES DUE TO MORE
BENIGN WEATHER AT THESE TIMES AND HELPING MANAGE EXTRA WORKLOAD ON
MORE IMPACTFUL HYDROLOGIC ISSUES.
FOR TUE...STARTING 12Z TUE THERE IS WILL BE AN UPPER SHORTWAVE
TROUGH OVER ND...WITH THE ASSOCIATED 995MB SFC LOW OVER NRN MN. THE
SYSTEM WILL MOVE TO HUDSON BAY BY 12Z WED WHILE DRAGGING A COLD
FRONT ACROSS THE CWA. THE COLD FRONT WILL ENCOUNTER VERY WARM LOW
LEVEL TEMPS AS 850MB TEMPS WILL BE AROUND 15C RESULTING IN HIGHS IN
THE 60S AND 70S. THUNDERSTORMS CERTAINLY APPEAR POSSIBLE...WITH EVEN
UP TO AROUND 1000 J/KG OF MUCAPE OVER THE REGION. THANKFULLY...SHEAR
WILL BE WEAK WHICH WILL FURTHER LIMIT SEVERE POTENTIAL. THERE COULD
BE SOME STRONGER STORMS...BUT NO SEVERE WEATHER IS EXPECTED AT THIS
TIME. DO SEE THE FRONT MOVE INTO WRN UPPER MI AROUND 00Z
WED...MOVING TO THE ERN U.P. BY 12Z WED. COULD ALSO SEE SOME HEAVY
RAINFALL...WHICH WILL NOT HELP HYDROLOGIC SITUATION DUE TO SNOWMELT
OVER THE CWA.
AFTER THE SYSTEM MOVES AWAY FROM THE AREA...THE CWA WILL BE SQUEEZED
BETWEEN A DEEPENING UPPER TROUGH JUST W OF THE CWA AND A
STRENGTHENING UPPER RIDGE JUST E OF THE CWA. AN 850MB TROUGH WILL BE
ANCHORED OVER THE CWA. ALL THIS WILL HAPPEN WED AND THU...BEFORE THE
UPPER TROUGH CLOSES OFF OVER MY BY FRI AS THE UPPER RIDGE GETS CUT
OFF AND MOVES INTO THE CWA FROM THE E. FGEN PRECIP ON THE NW SIDE OF
THE 850MB TROUGH WILL LEAD TO THE POSSIBILITY OF SIGNIFICANT PRECIP
OVER THE CENTRAL/WESTERN CWA WED NIGHT INTO FRI...MUCH OF WHICH MAY
BE SNOW OVER THE FARTHER W ZONES. THERE REMAINS A GOOD AMOUNT OF
UNCERTAINTY...BUT HEADLINE WORTHY SNOW DOES LOOK POSSIBLE OVER THE
WRN CWA. WITH AFOREMENTIONED HYDRO CONCERNS...WILL HAVE TO CONTINUE
TO CLOSELY LOOK AT PTYPE/AMOUNTS AS THE WEEK PROGRESSES.
WARMER TEMPS LOOK TO RETURN ON FRI AS 850MB TEMPS INCREASE UP TO
9C...WARMEST E. FOR NEXT WEEKEND...UNCERTAINTY INCREASES
SIGNIFICANTLY...SO WILL JUST USE A CONSENSUS OF MODEL GUIDANCE FOR
THIS PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 754 AM EDT MON APR 29 2013
THE ARRIVAL OF HIGH PRES AND DRIER AIR IN THE PRESENCE OF DAYTIME
HEATING LATER THIS MORNING SHOULD RESULT IN VFR CONDITIONS AT ALL 3
SITES TODAY. MORE CLOUDS IN ADVANCE OF A RETURNING WARM FRONT WILL
ARRIVE S TO N LATER TODAY. THERE MAY BE SOME -SHRA AND MVFR
CONDITIONS AT SAW BY LATE THIS EVENING CLOSER TO THE RETURNING FRONT
AND MOISTURE WITH AN UPSLOPE SE FLOW. COOLING THIS EVENING AND
OVERNIGHT ALONG WITH THE INFLUX OF LOW LEVEL MOISTURE IS LIKELY TO
BRING FOG TO SAW/CMX WITH LIFR OR VLIFR CONDITIONS OVERNIGHT.
DOWNSLOPE FLOW AT IWD SHOULD LIMIT FOG DEVELOPMENT.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 518 AM EDT MON APR 29 2013
WINDS SHOULD STAY BELOW 25KT THROUGH THE PERIOD WITH NO GALES
EXPECTED. NO STRONG SYSTEMS WILL BE COMING CLOSE TO THE AREA...SO NO
STRONG PRESSURE GRADIENTS ARE EXPECTED.
&&
.HYDROLOGY...
ISSUED AT 518 AM EDT MON APR 29 2013
YESTERDAY SAW TEMPS IN THE 60S AND 70S...FOLLOWED BY LOWS LAST NIGHT
IN THE 40S...WHICH HAS KEPT THE MELTING GOING ACROSS THE CWA. SNOW
DEPTHS HAVE FALLEN 15-20 INCHES IN THE LAST WEEK. THE MOST SNOW
REMAINS ON THE GROUND ACROSS NORTHERN UPPER MICHIGAN IN THE INLAND
AND HIGHER TERRAIN AREAS. STILL HAVE TO MELT ANOTHER 12-20 INCHES OF
SNOW IN SOME OF THESE AREAS. TROUGH MOVING THROUGH TONIGHT INTO
TODAY IS DROPPING GENERALLY AROUND 0.25 INCHES OF RAIN...BUT IN SOME
CASES UP TO .5 INCHES HAS FALLEN. ADDITIONAL RAIN WITH POSSIBLE
THUNDERSTORMS MAY OCCUR TUESDAY INTO TUESDAY NIGHT AS A COLD FRONT
WORKS ACROSS UPPER MICHIGAN. HIGHER MOISTURE OVER THE AREA MAY RESULT
IN HEAVY DOWNPOURS WITH ANY THUNDERSTORMS. MUCH COOLER TEMPERATURES
EXPECTED FOR REST OF WEEK BEHIND THE FRONT. ADDITIONAL CHANCES OF
RAIN AND EVEN SNOW WILL ALSO CONTINUE ACROSS UPPER MICHIGAN FOR THE
REST OF THE WEEK. SO...EVEN THOUGH TEMPERATURES WILL BE COOLER THIS
MAY BE OFFSET BY THE ADDITIONAL PRECIPITATION THAT MAY OCCUR.
RIVERS OF PARTICULAR CONCERN DUE TO MELTING WILL BE THE TRAP ROCK
RIVER...THE STURGEON RIVER OF BARAGA/HOUGHTON COUNTIES...THE
PESHEKEE RIVER...THE PAINT RIVER NEAR CRYSTAL FALLS...THE ONTONAGON
RIVER AT EWEN AND EVENTUALLY THE MICHIGAMME RIVER NEAR REPUBLIC AND
WITCH LAKE. MELTING SCENARIOS STILL REMAIN THE BIGGEST CONFIDENCE
REDUCERS IN RIVER FORECASTS FOR THE PESHEKEE AND MICHIGAMME BASINS
WHERE MOST OF THE MELTING HAS NOT HIT ANY OBSERVED RIVER POINTS
YET...ALTHOUGH READINGS WILL BE GATHERED FROM THE PESHEKEE RIVER AND
LAKE MICHIGAMME THIS MORNING BY NWS PERSONNEL WHICH SHOULD HELP GET
A BETTER IDEA OF MELTING CONDITIONS INTO THE BASIN. AT OTHER
LOCATIONS...SUFFICIENT RUNOFF FROM MELTING HAS BEEN OBSERVED TO MORE
ACCURATELY GET A HANDLE OF MELT RATES FOR THE RIVER MODELS. NWS
SURVEY OF THE PESHEKEE RIVER ON SATURDAY REVEALED THICK ICE COVERING
MOST OF THE RIVER NEAR AND DOWNSTREAM OF THE CHPM4 RIVER GAUGING
LOCATION /AUTOMATED GAUGE DISCONTINUED BUT OBS ARE BEING TAKEN USING
A WIRE WEIGHT GAUGE AT THE LOCATION/ AND THICK ICE COVER ON MOST OF
LAKE MICHIGAMME WHICH THE PESHEKEE DRAINS INTO. ICE JAMS MAY CAUSE
SIGNIFICANT PROBLEMS AS THE RIVER RISES THROUGH MONDAY. MAIN STEM
RIVERS ARE NOT THE ONLY HAZARD...AS THERE IS ALSO A THREAT OF AREAL
FLOOD PROBLEMS WITH SMALLER CREEKS/STREAMS AND STANDING WATER ON
ROADS. HAVE RECEIVED SOME SPORADIC REPORTS OF AREAL TYPE
FLOODING...BUT NOT ENOUGH SIGNIFICANT REPORTS FOR HAZARD ISSUANCE.
FOR COMPLETE DETAILS...SEE THE HYDROLOGIC OUTLOOK /ESF/ AND THE
LATEST RIVER FLOOD WATCHES...WARNINGS AND ADVISORIES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...JLB
MARINE...JLB
HYDROLOGY...TITUS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
521 AM EDT MON APR 29 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 518 AM EDT MON APR 29 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A STRONG 160 KNOT 250-300 MB
JET MOVING INTO THE PAC NW AND A MAINLY ZONAL FLOW DOWNSTREAM TO THE
NRN GREAT LAKES. AT THE SFC...A COLD FRONT EXTENDED FROM LOW PRES
OVER HUDSON BAY TO NEAR JAMES BAY AND THROUGH WRN UPPER MI INTO NW
IA. THE COMBINATION OF LOW LEVEL CONV NEAR THE FRONT AND A WEAK
SHRTWV INTO UPPER SUPPORTED AN AREA OF LIGHT SHOWERS ACROSS CNTRL
UPPER MI INTO ERN LAKE SUPERIOR. HIGH PRES FROM THE NRN PLAINS WAS
BUILDING TOWARD THE REGION BRINGING IN DRIER AIR ALONG WITH CLEARING
SKIES FROM NRN MN INTO WRN LAKE SUPERIOR AND WRN UPPER MI. WITH SOME
LEFTOVER LOW LEVEL MOISTURE FROM THE LIGHT RAIN AND MELTING SNOW
ALONG WITH RADIATIONAL COOLING...SOME FOG HAD DEVELOPED FROM IWD TO
CMX.
RADAR/SATELLITE TRENDS SUGGEST THAT THE AREA OF SHOWERS WILL MOVE
THROUGH THE REST OF THE ERN HALF OF THE CWA THIS MORNING AS THE
FRONT GRADUALLY WEAKENS OVER SRN UPPER MI. AS ANOTHER WEAK SHORTWAVE
OVER SOUTH DAKOTA MOVES TOWARD THE AREA LATE THIS AFTERNOON AND
EVENING...MODELS SUGGEST THAT PCPN WILL AGAIN DEVELOP AND LIFT TO
THE NORTHEAST. HOWEVER...THERE REMAINS SOME UNCERTAINTY WITH THE
TIMING OF THE PCPN DEVELOPMENT AND MOVEMENT AND ON HOW FAR TO THE
NORTH INTO CNTRL UPPER MI THE PCPN WILL EXPAND. SO...ONLY CHANCE
POPS WERE INCLUDED FOR NOW. INSTABILITY TO SUPPORT TSRA...PER MDLS
MUCAPE...IS EXPECTED TO REMAIN SOUTH OF THE AREA.
FARTHER TO THE NORTHWEST...DRY CONDITIONS WILL PREVAIL WITH A
SUNSHINE AND WARM CONDITIONS. WITH 850 MB TEMPS AROUND 8C...TEMPS
SHOULD AGAIN CLIMB INTO THE MID 60S. READINGS IN THE UPPER 50S AND
LOWER 60S AND EXPECTED WHERE GREATER CLOUD COVER PREVAILS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 518 AM EDT MON APR 29 2013
EXTENDED FORECAST BECOMES MORE COMPLEX WITH ADDITION OF
THUNDERSTORMS /SOME ON THE STRONGER SIDE/ TUE AND TUE NIGHT AND SNOW
WED NIGHT INTO FRI. WILL FOCUS ON THESE TWO TIME FRAMES DUE TO MORE
BENIGN WEATHER AT THESE TIMES AND HELPING MANAGE EXTRA WORKLOAD ON
MORE IMPACTFUL HYDROLOGIC ISSUES.
FOR TUE...STARTING 12Z TUE THERE IS WILL BE AN UPPER SHORTWAVE
TROUGH OVER ND...WITH THE ASSOCIATED 995MB SFC LOW OVER NRN MN. THE
SYSTEM WILL MOVE TO HUDSON BAY BY 12Z WED WHILE DRAGGING A COLD
FRONT ACROSS THE CWA. THE COLD FRONT WILL ENCOUNTER VERY WARM LOW
LEVEL TEMPS AS 850MB TEMPS WILL BE AROUND 15C RESULTING IN HIGHS IN
THE 60S AND 70S. THUNDERSTORMS CERTAINLY APPEAR POSSIBLE...WITH EVEN
UP TO AROUND 1000 J/KG OF MUCAPE OVER THE REGION. THANKFULLY...SHEAR
WILL BE WEAK WHICH WILL FURTHER LIMIT SEVERE POTENTIAL. THERE COULD
BE SOME STRONGER STORMS...BUT NO SEVERE WEATHER IS EXPECTED AT THIS
TIME. DO SEE THE FRONT MOVE INTO WRN UPPER MI AROUND 00Z
WED...MOVING TO THE ERN U.P. BY 12Z WED. COULD ALSO SEE SOME HEAVY
RAINFALL...WHICH WILL NOT HELP HYDROLOGIC SITUATION DUE TO SNOWMELT
OVER THE CWA.
AFTER THE SYSTEM MOVES AWAY FROM THE AREA...THE CWA WILL BE SQUEEZED
BETWEEN A DEEPENING UPPER TROUGH JUST W OF THE CWA AND A
STRENGTHENING UPPER RIDGE JUST E OF THE CWA. AN 850MB TROUGH WILL BE
ANCHORED OVER THE CWA. ALL THIS WILL HAPPEN WED AND THU...BEFORE THE
UPPER TROUGH CLOSES OFF OVER MY BY FRI AS THE UPPER RIDGE GETS CUT
OFF AND MOVES INTO THE CWA FROM THE E. FGEN PRECIP ON THE NW SIDE OF
THE 850MB TROUGH WILL LEAD TO THE POSSIBILITY OF SIGNIFICANT PRECIP
OVER THE CENTRAL/WESTERN CWA WED NIGHT INTO FRI...MUCH OF WHICH MAY
BE SNOW OVER THE FARTHER W ZONES. THERE REMAINS A GOOD AMOUNT OF
UNCERTAINTY...BUT HEADLINE WORTHY SNOW DOES LOOK POSSIBLE OVER THE
WRN CWA. WITH AFOREMENTIONED HYDRO CONCERNS...WILL HAVE TO CONTINUE
TO CLOSELY LOOK AT PTYPE/AMOUNTS AS THE WEEK PROGRESSES.
WARMER TEMPS LOOK TO RETURN ON FRI AS 850MB TEMPS INCREASE UP TO
9C...WARMEST E. FOR NEXT WEEKEND...UNCERTAINTY INCREASES
SIGNIFICANTLY...SO WILL JUST USE A CONSENSUS OF MODEL GUIDANCE FOR
THIS PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 132 AM EDT MON APR 29 2013
EXPECT A PERIOD OF MVFR CONDITIONS TO DVLP EARLY THIS MRNG AS
MOISTER LLVL AIR FOLLOWS A BAND OF -SHRA ACRS UPR MI. THE ARRIVAL OF
HI PRES AND DRIER AIR NOW IN THE NRN PLAINS IN THE PRESENCE OF
DAYTIME HEATING LATER THIS MRNG SHOULD BRING AN IMPROVEMENT TO VFR
CONDITIONS AT ALL 3 SITES. MORE CLDS IN ADVANCE OF RETURNING WARM
FNT WL ARRIVE S TO N LATER TODAY. THERE MAY BE SOME -SHRA AND MVFR
CONDITIONS AT SAW BY LATE THIS EVNG CLOSER TO THE RETURNING FNT/MSTR
WITH AN UPSLOPE SE FLOW.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 518 AM EDT MON APR 29 2013
WINDS SHOULD STAY BELOW 25KT THROUGH THE PERIOD WITH NO GALES
EXPECTED. NO STRONG SYSTEMS WILL BE COMING CLOSE TO THE AREA...SO NO
STRONG PRESSURE GRADIENTS ARE EXPECTED.
&&
.HYDROLOGY...
ISSUED AT 518 AM EDT MON APR 29 2013
YESTERDAY SAW TEMPS IN THE 60S AND 70S...FOLLOWED BY LOWS LAST NIGHT
IN THE 40S...WHICH HAS KEPT THE MELTING GOING ACROSS THE CWA. SNOW
DEPTHS HAVE FALLEN 15-20 INCHES IN THE LAST WEEK. THE MOST SNOW
REMAINS ON THE GROUND ACROSS NORTHERN UPPER MICHIGAN IN THE INLAND
AND HIGHER TERRAIN AREAS. STILL HAVE TO MELT ANOTHER 12-20 INCHES OF
SNOW IN SOME OF THESE AREAS. TROUGH MOVING THROUGH TONIGHT INTO
TODAY IS DROPPING GENERALLY AROUND 0.25 INCHES OF RAIN...BUT IN SOME
CASES UP TO .5 INCHES HAS FALLEN. ADDITIONAL RAIN WITH POSSIBLE
THUNDERSTORMS MAY OCCUR TUESDAY INTO TUESDAY NIGHT AS A COLD FRONT
WORKS ACROSS UPPER MICHIGAN. HIGHER MOISTURE OVER THE AREA MAY RESULT
IN HEAVY DOWNPOURS WITH ANY THUNDERSTORMS. MUCH COOLER TEMPERATURES
EXPECTED FOR REST OF WEEK BEHIND THE FRONT. ADDITIONAL CHANCES OF
RAIN AND EVEN SNOW WILL ALSO CONTINUE ACROSS UPPER MICHIGAN FOR THE
REST OF THE WEEK. SO...EVEN THOUGH TEMPERATURES WILL BE COOLER THIS
MAY BE OFFSET BY THE ADDITIONAL PRECIPITATION THAT MAY OCCUR.
RIVERS OF PARTICULAR CONCERN DUE TO MELTING WILL BE THE TRAP ROCK
RIVER...THE STURGEON RIVER OF BARAGA/HOUGHTON COUNTIES...THE
PESHEKEE RIVER...THE PAINT RIVER NEAR CRYSTAL FALLS...THE ONTONAGON
RIVER AT EWEN AND EVENTUALLY THE MICHIGAMME RIVER NEAR REPUBLIC AND
WITCH LAKE. MELTING SCENARIOS STILL REMAIN THE BIGGEST CONFIDENCE
REDUCERS IN RIVER FORECASTS FOR THE PESHEKEE AND MICHIGAMME BASINS
WHERE MOST OF THE MELTING HAS NOT HIT ANY OBSERVED RIVER POINTS
YET...ALTHOUGH READINGS WILL BE GATHERED FROM THE PESHEKEE RIVER AND
LAKE MICHIGAMME THIS MORNING BY NWS PERSONNEL WHICH SHOULD HELP GET
A BETTER IDEA OF MELTING CONDITIONS INTO THE BASIN. AT OTHER
LOCATIONS...SUFFICIENT RUNOFF FROM MELTING HAS BEEN OBSERVED TO MORE
ACCURATELY GET A HANDLE OF MELT RATES FOR THE RIVER MODELS. NWS
SURVEY OF THE PESHEKEE RIVER ON SATURDAY REVEALED THICK ICE COVERING
MOST OF THE RIVER NEAR AND DOWNSTREAM OF THE CHPM4 RIVER GAUGING
LOCATION /AUTOMATED GAUGE DISCONTINUED BUT OBS ARE BEING TAKEN USING
A WIRE WEIGHT GAUGE AT THE LOCATION/ AND THICK ICE COVER ON MOST OF
LAKE MICHIGAMME WHICH THE PESHEKEE DRAINS INTO. ICE JAMS MAY CAUSE
SIGNIFICANT PROBLEMS AS THE RIVER RISES THROUGH MONDAY. MAIN STEM
RIVERS ARE NOT THE ONLY HAZARD...AS THERE IS ALSO A THREAT OF AREAL
FLOOD PROBLEMS WITH SMALLER CREEKS/STREAMS AND STANDING WATER ON
ROADS. HAVE RECEIVED SOME SPORADIC REPORTS OF AREAL TYPE
FLOODING...BUT NOT ENOUGH SIGNIFICANT REPORTS FOR HAZARD ISSUANCE.
FOR COMPLETE DETAILS...SEE THE HYDROLOGIC OUTLOOK /ESF/ AND THE
LATEST RIVER FLOOD WATCHES...WARNINGS AND ADVISORIES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...KC
MARINE...JLB
HYDROLOGY...TITUS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
133 AM EDT MON APR 29 2013
.UPDATE...
ISSUED AT 811 PM EDT SUN APR 28 2013
ADDED A SCHC FOR TS OVER THE FAR WRN CWA THIS EVNG TO ACCOUNT FOR
RATHER NARROW LINE OF CONVECTION TAKING SHAPE IN NW WI IN ADVANCE
OF HIER H85 DEWPTS/SSI DOWN TO -1C TO -2C. DRY LLVL AIR WITH INVERTED
V LLVL TEMP/DEWPT PROFILES EVIDENT ON RUC ANALYSIS SDNGS SUG ANY PCPN
WL BE RELATIVELY LGT AND NOT EXACERBATE SN MELT RUNOFF. AS THIS LINE
PRESSES FARTHER TO THE E...EXPECT THE CONVECTION TO WEAKEN WITH ONSET
OF NOCTURNAL COOLING AND AS THE CONVECTION RUNS INTO DRIER ANTECEDENT
AIRMASS.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 402 PM EDT SUN APR 28 2013
UPPER AIR PATTERN CONSISTS OF A 500 MB CLOSED LOW OVER ILLINOIS WITH
AN ASSOCIATED TROUGH. UPPER FLOW ACROSS THE NORTHERN U.S. IS FAIRLY
ZONAL WITH A MINOR SHORTWAVE OVER EASTERN MT THIS MORNING. THIS
SHORTWAVE MOVES INTO THE AREA TONIGHT AND EXITS THE AREA MON
AFTERNOON. NAM SHOWS SOME 850-500 MB Q-VECTOR CONVERGENCE MOVING
THROUGH ALONG WITH DEEPER MOISTURE TONIGHT INTO MONDAY. GFS AND
ECMWF SHOW ABOUT THE SAME THING.
MOISTURE IS PRETTY LIMITED WITH THIS SYSTEM AND SEE A NARROW BAND OF
PCPN MOVING THROUGH TONIGHT INTO MON WITH THE BAND GETTING HUNG UP
OVER THE EAST LATER IN THE DAY. WITH LIMITED MOISTURE...DO NOT WANT
TO GO MORE THAN LIKELY POPS OR HIGH CHANCE AS THIS BAND SLOWLY MOVES
THROUGH THE AREA. QPF AMOUNTS UP TO 0.30 INCH WITH THIS EVENT SEEM
REASONABLE. OTHERWISE...DID NOT MAKE TOO MANY CHANGES TO THE GOING
FORECAST EXCEPT TO DRY THE WEST OUT A BIT FOR MONDAY AS FRONTAL ZONE
IS ALREADY EAST OF THEM BY AFTERNOON. DID NOT MAKE TOO MANY CHANGES
TO TEMPERATURES EITHER.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 402 PM EDT SUN APR 28 2013
AFTER A BRIEF PERIOD OF ZONAL FLOW AND A TASTE OF SPRING...UPPER
HEIGHT PATTERN BECOMES MORE AMPLIFIED BY MID WEEK AS TROUGH DEEPENS
OVER WESTERN CANADA AND RIDGING BUILDS FROM THE LOWER GREAT LAKES
TO EASTERN CANADA. BY LATE WEEK...MODELS INDICATE CUTOFF LOW FORMING
OVER THE CNTRL CONUS. LOW PRESSURE TROUGH MOVES THROUGH EARLY IN THE
WEEK...THEN STALLS OUT JUST TO THE EAST OF UPR GREAT LAKES. BOUNDARY
WILL STAY CLOSE ENOUGH TO UPR MICHIGAN TO RESULT IN CHANCES OF PRECIP
THROUGH THE REST OF THE WEEK.
SFC FRONT ON MONDAY EVENING SHOULD BE JUST TO EAST AND SOUTH OF CWA.
SECONDARY SHORTWAVE MOVING THROUGH IN WSW FLOW ALOFT OUT AHEAD OF
LARGER SCALE TROUGHING TO THE WEST COULD HELP TO DEVELOP MORE
SHOWERS PROBABLY CLOSER TO THE SFC BOUNDARY. HIGHER H85 DWPNTS
LIKELY WILL BE INTERCEPTED BY SFC BOUNDARY OVER NORTHEAST WI TO
ACROSS LK MICHIGAN AND NORTHERN LOWER MICHIGAN. ADVECTION OF THE
MOISTURE THEN LIFTS ACROSS EASTERN HALF OF UPR MICHIGAN THROUGH THE
NIGHT.
LARGER SHORTWAVE/MID-UPPER LEVEL JET STREAK PUSHES ACROSS NORTHERN
PLAINS LATER MONDAY NIGHT AND ACROSS NORTHERN MINNESOTA AND WESTERN
LK SUPERIOR TUESDAY INTO TUESDAY EVENING. MODELS DIFFER ON WHICH
PART OF WAVE IS STRONGER...AND THUS ARE DIFFERENT ON PRIMARY SFC LOW
PLACEMENT. GFS/GEM-NH SHOW A NORTHERN LOW TRACK ALONG MINNESOTA AND
ONTARIO BORDER WHILE ECMWF AND NAM INDICATE DOUBLE BARRELLED LOW
FROM MINNESOTA/ONTARIO AND INTO CENTRAL MINNESOTA. YET...MODELS ALL
SHOW COLD FRONT INTO CNTRL UPR MICHIGAN AROUND 00Z ON WEDNESDAY.
DIFFERNCE MAY IMPACT POTENTIAL FOR CLOUDS AND PRECIP WORKING ACROSS
WESTERN HALF OF UPR MICHIGAN DURING THE FIRST PART OF THE DAY...
WHICH AFFECTS HOW MUCH WARMING WILL BE SEEN AHEAD OF COLD FRONT.
PREFER THE ECMWF/NAM/WPC HAND DRAWN PROG IDEA WITH SECOND SFC LOW
AND POSSIBLE WARM FRONT ACROSS MN/CNTRL WI. SFC-BLYR DWPNTS INTO 50S
WITH THE APPROACHING FRONT ALONG WITH ELEVATED MID-LEVEL LAPSE RATES
SUPPORTS MENTION OF TSRA. BEST CHANCE MID-LATE AFTN WOULD BE OVER
SOUTHWEST AND SOUTH CENTRAL...WITH CHANCES TUESDAY EVENING MOVING
ACROSS REST OF EASTERN HALF OF UPR MICHIGAN FOLLOWING INSTABILITY
AXIS AND STRONGER H85 WINDS. CURRENT POP FORECAST SHOWS EXPECTED
TRENDS WELL. WILL TRIM BACK POPS/QPF OVER THE NORTHWEST CWA ON
TUESDAY EVENING THOUGH IN WAKE OF FRONT AND INSTABILITY AXIS.
APPEARS GREATEST INSTABILITY ON TUESDAY WILL STAY SOUTH OF AREA
CLOSER TO SFC DWPNTS NEAR 60F. SINCE STRONGER WINDS AT H7/H5/H3 ARE
NORTHWEST...REDUCING DEEP LAYER SHEAR...POTENTIAL FOR ANY SVR STORMS
IS LOW OVR CWA. HOWEVER...H85 DWPNTS OVER 10C AND SFC FRONT RUNNING
PARALLEL TO UPPER HEIGHTS COULD RESULT IN HEAVY DOWNPOURS IN THE
CONVECTIVE ELEMENTS. WILL BE SOMETHING TO WATCH AS ANY HEAVIER RAIN
WOULD ONLY AGGREVATE THE ONGOING SNOWMELT AND RISING RIVER LEVELS.
RIDGING ALOFT CONTINUES BUILDING TUESDAY NIGHT INTO WEDNESDAY OVER
THE LOWER GREAT LAKES. UPPER PATTERN WILL CONTINUE TO SLOW. SFC
FRONT THAT MOVES THROUGH ON TUESDAY EVENING MAY NOT EVEN MAKE IT
EAST OF EASTERN UPR OR NORTHERN LOWER MICHIGAN BY 12Z WEDNESDAY. UPR
LAKES WILL BE ON LEADING SIDE OF LARGER TROUGH AND IN AREA OF UPPER
JET DIVERGENCE/H7-H5 JET WEDNESDAY THROUGH THURSDAY. FEASIBLE THAT
ECMWF/GFS IDEA SHOWING PERSISTENT RIBBON OF QPF THROUGH THURSDAY IS
CORRECT WITH THIS LARGE SCALE SETUP AND SINCE UPPER LAKES IS WITHIN
H85 TROUGH/AXIS OF HIGHER H85 DWPNTS NEAR +10C WITH AT LEAST SOME
AREAS OF H85-H7 FRONTOGENESIS. MAIN QUESTION IS EXACTLY WHERE THIS
NARROW RIBBON OF PRECIP WILL SET UP. CONSENSUS OF GFS/ECMWF POINT
TO WESTERN HALF OF UPR MICHIGAN. EXACT LOCATION AND INTENSITY OF THE
PRECIP WILL BE CRITICAL AS IT WILL BE FALLING OVER BASINS THAT
ALREADY SHOULD BE SEEING FLOODING AT THAT TIME. COLDER TEMPS STILL
APPEAR IN THE OFFING JUST IN WAKE OF THE SHARP H85 TROUGH. SINCE
UPPER PATTERN REMAINS AMPLIFIED AND BLOCKED UP WITH SOMEWHAT OF A
OMEGA BLOCK LOOK FROM CNTRL CONUS INTO THE EASTERN ATLANTIC...HAVE
TO GO WITH ECMWF IDEA OF FARTHER WEST POSITION OF H85 TROUGH AND
LESS COLD AIR INTO UPR LAKES. EVEN WITH ECMWF THERMAL FIELDS...
WESTERN AND NORTH CENTRAL PORTIONS OF UPR MICHIGAN WOULD BE ENOUGH
ON THE COLD SIDE TO SEE MAINLY SNOW THURSDAY NIGHT INTO FRIDAY
MORNING. POSSIBLE THAT SOME SNOW ACCUMULATIONS COULD OCCUR OVER
THE HIGHER TERRAIN AREAS.
REST OF THE FORECAST PRETTY UNCERTAIN AS IT WILL ALL DEPEND ON HOW
FAR NORTH CLOSED OFF UPPER LOW MEANDERS NEXT WEEKEND. OVERALL WILL
REMAIN COOL AND UNSETTLED THROUGH THE WEEKEND AND POSSIBLY INTO
EARLY NEXT WEEK AS WELL SINCE THE UPPER LOW ONLY SLOWLY LIFTS OUT OF
THE MIDWEST/GREAT LAKES REGION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 132 AM EDT MON APR 29 2013
EXPECT A PERIOD OF MVFR CONDITIONS TO DVLP EARLY THIS MRNG AS
MOISTER LLVL AIR FOLLOWS A BAND OF -SHRA ACRS UPR MI. THE ARRIVAL OF
HI PRES AND DRIER AIR NOW IN THE NRN PLAINS IN THE PRESENCE OF
DAYTIME HEATING LATER THIS MRNG SHOULD BRING AN IMPROVEMENT TO VFR
CONDITIONS AT ALL 3 SITES. MORE CLDS IN ADVANCE OF RETURNING WARM
FNT WL ARRIVE S TO N LATER TODAY. THERE MAY BE SOME -SHRA AND MVFR
CONDITIONS AT SAW BY LATE THIS EVNG CLOSER TO THE RETURNING FNT/MSTR
WITH AN UPSLOPE SE FLOW.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 402 PM EDT SUN APR 28 2013
WINDS SHOULD STAY BELOW 25KT THROUGH THE PERIOD WITH NO GALES
EXPECTED. NO STRONG SYSTEMS WILL BE COMING CLOSE TO THE AREA...SO NO
STRONG PRESSURE GRADIENTS ARE EXPECTED.
&&
.HYDROLOGY...
ISSUED AT 811 PM EDT SUN APR 28 2013
UPDATE...OPTED TO ISSUE FLOOD ADVY FOR THE CHOCOLAY RIVER AT HARVEY
UNTIL TUE AFTN TO ACCOUNT FOR STEEP RISE OF OBSVD WATER LVL AT THAT
SITE. MOST RECENT OB AT 730 PM SHOWED THE LVL AT 9.38 FT...JUST AN
INCH OR TWO BLO BANKFULL. THE UPDATED RFC FCST SHOWS THIS GAUGE
PEAKING AT 9.8 FT MON AFTN...JUST UNDER THE 10.0 FLOOD STAGE. THIS
LATEST FCST SHOWS THE RIVER FALLING BLO BANKFULL TUE AFTN.
ANOTHER DAY IN THE 60S AND 70S HAS KEPT THE MELTING GOING ACROSS THE
CWA. SNOW DEPTHS HAVE FALLEN 15-20 INCHES IN THE LAST WEEK. THE MOST
SNOW REMAINS ON THE GROUND ACROSS NORTHERN UPPER MICHIGAN IN THE
INLAND AND HIGHER TERRAIN AREAS. STILL HAVE TO MELT ANOTHER 12-20
INCHES OF SNOW IN SOME OF THESE AREAS. TROUGH MOVING THROUGH TONIGHT
INTO MONDAY COULD BRING SHOWERS...BUT RAIN AMOUNTS WILL STAY BLO
0.25 INCH. ADDITIONAL RAIN WITH POSSIBLE TSRA MAY OCCUR TUESDAY AS A
COLD FRONT WORKS ACROSS UPR MICHIGAN. HIGHER MOISTURE OVER THE AREA
MAY RESULT IN HEAVY DOWNPOURS WITH ANY THUNDERSTORMS. MUCH COOLER
TEMPERATURES EXPECTED FOR REST OF WEEK BEHIND THE FRONT. ADDITIONAL
CHANCES OF RAIN AND EVEN SNOW WILL ALSO CONTINUE ACROSS UPR MICHIGAN
FOR THE REST OF THE WEEK. SO...EVEN THOUGH TEMPERATURES WILL BE
COOLER THIS MAY BE OFFSET BY THE ADDITIONAL PRECIPITATION THAT MAY
OCCUR.
RIVERS OF PARTICULAR CONCERN DUE TO MELTING WILL BE THE TRAP ROCK
RIVER...THE STURGEON RIVER OF BARAGA/HOUGHTON COUNTIES...THE
PESHEKEE RIVER...THE PAINT RIVER NEAR CRYSTAL FALLS...AND EVENTUALLY
THE MICHIGAMME RIVER NEAR REPUBLIC AND WITCH LAKE. MELTING SCENARIOS
STILL REMAIN THE BIGGEST CONFIDENCE REDUCERS IN RIVER FORECASTS AT
THIS POINT...AND IF THE RIVER FORECAST CENTER HAS TO INCREASE THE
MELT FACTOR CORRECTION GOING INTO THE RIVER MODELS THE FORECASTS
WILL LIKELY END UP QUITE A BIT HIGHER. MELT CORRECTION FACTOR
ALREADY WAS INCREASED EARLIER THIS WEEKEND FOR THE MEN RIVER
FORECAST GROUP /RIVERS THAT DRAIN INTO THE MENOMINEE RIVER/...WHICH
HAS KEPT FORECASTS UP TO NEAR RECORD STAGE AT PESHEKEE AND MODERATE
FLOOD STAGE DOWNSTREAM ON THE MICHIGAMME RIVER NEAR REPUBLIC/WITCH
LAKE. WFO SURVEY OF THE PESHEKEE RIVER ON SATURDAY REVEALED THICK
ICE COVERING MOST OF THE RIVER AND THICK ICE COVER ON MOST OF LAKE
MICHIGAMME WHICH THE PESHEKEE DRAINS INTO. ICE JAMS MAY CAUSE
SIGNIFICANT PROBLEMS AS THE RIVER RISES THROUGH MONDAY. MAIN STEM
RIVERS ARE NOT THE ONLY HAZARD...AS THERE IS ALSO A THREAT OF AREAL
FLOOD PROBLEMS WITH SMALLER CREEKS/STREAMS AND STANDING WATER ON
ROADS. FOR COMPLETE DETAILS...SEE THE HYDROLOGIC OUTLOOK /ESF/ AND
THE LATEST RIVER FLOOD WATCHES AND WARNINGS /FFAMQT AND FFWMQT/.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...KC
SHORT TERM...07
LONG TERM...JLA
AVIATION...KC
MARINE...07
HYDROLOGY...KC
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
259 PM CDT MON APR 29 2013
.SHORT TERM...(THROUGH LATE TONIGHT)
ISSUED AT 256 PM CDT MON APR 29 2013
PRIMARY WEATHER CONCERN FOR TONIGHT IS THE POSSIBILITY OF CONVECTION
ACROSS NORTHERN MISSOURI AND WEST CENTRAL ILLINOIS. RUC CONTINUES
TO FORECAST COPIOUS AMOUNTS OF CAPE SOUTH OF A Q-STATIONARY FRONT
EXTENDING THROUGH NORTHEAST KANSAS INTO SOUTHEAST NEBRASKA AND
WESTERN IOWA LATE THIS AFTERNOON. GREATEST VALUES EXCEED 4000 J/KG
ACROSS PARTS OF WESTERN AND CENTRAL MISSOURI. HOWEVER...RUC ALSO
APPEARS TO BE 3 TO 5 DEGREES TOO MOIST ON DEWPOINT FORECASTS LATER
THIS AFTERNOON INTO THE EVENING WHICH WOULD DEFINITELY ACCOUNT FOR
THE GIHEMOUS CAPE VALUES. THAT BEING SAID...THERE IS SOME
AGITATED CU OVER SOUTH CENTRAL MISSOURI AND ONE LONE THUNDERSTORM
OVER NORTHERN ARKANSAS...SO THERE`S OBVIOUSLY SOME INSTABILITY OUT
THERE. CURRENT THINKING IS THAT THE ISOLATED CONVECTION OVER SOUTH
CENTRAL MISSOURI WON`T MAKE IT TO OUR AREA...AND THAT CONVECTION
WILL FIRE CLOSER TO THE BAROCLINIC ZONE IN NEBRASKA LATE THIS
AFTERNOON/EARLY EVENING AND RIDE UP ACROSS IOWA. COULD SEE THE TAIL
END OF ANY CONVECTIVE COMPLEX THAT FORMS AFFECT NORTHERN PORTIONS OF
THE CWFA SO HAVE KEPT LOW CHANCE POPS UP THERE. OTHERWISE...SHOULD
BE MILD AND QUIET NIGHT.
CARNEY
.LONG TERM...(TUESDAY THROUGH NEXT MONDAY)
ISSUED AT 256 PM CDT MON APR 29 2013
TUESDAY THROUGH THURSDAY...CONFIDENCE MEDIUM
WELL ABOVE NORMAL TEMPERATURES ARE EXPECTED TUESDAY AND WEDNESDAY
AHEAD OF THE DIGGING TROF AND COLD FRONT. CAN`T ARGUE MUCH WITH MOS
GUIDANCE WITH HIGHS IN THE LOWER TO MIDDLE 80S AND LOWS IN THE 60S.
MODEL GUIDANCE IN GOOD AGREEMENT THAT COLD FRONT WILL WAIT UNTIL
WEDNESDAY NIGHT AND THURSDAY MORNING TO START MOVING ACROSS THE CWA.
PRECIPITATION CHANCES TO INCREASE FROM THE WEST...BUT BELIEVE A
LARGE PART OF THE CWA WILL REMAIN DRY THROUGH THURSDAY MORNING.
THIS WILL CHANGE THURSDAY AFTERNOON. THE MAIN BAND OF RAIN WILL EDGE
INTO CENTRAL AND NORTHEAST MISSOURI...WHILE CONVECTION FIRES ON THE
FRONT ITSELF ALONG AND EAST OF THE MISSISSIPPI RIVER. I AM SURE
SOMEONE IN THE MIDDLE OF THESE TWO AREAS OF PRECIPITATION MAY REMAIN
DRY...BUT IT IS TOO FAR OUT TO GET TOO CUTE WITH POP GRADIENTS.
SHOULD BE QUITE A TEMPERATURE CONTRAST ACROSS THE CWA ON THURSDAY
WITH STEADY OR SLOWLY FALLING TEMPERATURES IN THE 40S IN THE WESTERN
CWA...TO THE LOW/MIDDLE 70S IN SOUTH CENTRAL ILLINOIS.
FRIDAY THROUGH MONDAY...CONFIDENCE LOW
MODELS ARE STILL HAVING SOME DIFFICULTY IN HOW THEY HANDLE THE TRACK
OF THE CLOSED OFF LOW LATE THIS WEEK AND WEEKEND. PREFER TO KEEP
FORECAST TREND THE SAME...ESSENTIALLY FOLLOWING HPC GUIDANCE AND 12Z
ECWMF...WITH THE CLOSED OFF LOW DEVELOPING TO OUR WEST AND SPINNING
NORTHEAST ACROSS THE MIDWEST TOWARD THE GREAT LAKES THIS WEEKEND.
MARCHED THE MAIN BAND OF RAIN EAST THURSDAY NIGHT AND FRIDAY WITH
LIKELY POPS AND THEN CONTINUED LOW CHANCE POPS FOR RAIN SHOWERS
THROUGH MONDAY AS AREA EXPECTED TO REMAIN AT LEAST IN THE
VICINITY OF THE COLD CORE SYSTEM. FORECAST RAINFALL AMOUNTS WITH
THIS SOLUTION WOULD BE ON THE ORDER OF 1 TO 1.5 INCHES FOR THE
EVENT.
TEMPERATURES STILL ON TRACK TO FALL BACK BELOW NORMAL FRIDAY AND
SATURDAY...BUT SLOWLY WARM SUNDAY AND MONDAY AS INFLUENCE OF THE
SYSTEM WAINS BY THE BEGINING OF NEXT WEEK.
NOTE...THE 12Z GFS AND GEM CAME IN QUITE A BIT FURTHER TO THE
SOUTHWEST AND MUCH SLOWER WITH THE SYSTEM...WHICH WOULD RESULT IN A
PROLONGED PERIOD OF RAIN AS THE FRONT AND TROPICAL FETCH PARK ITSELF
ACROSS THE MISSISSIPPI RIVER VALLEY FOR THE ENTIRE WEEKEND. THIS
SOLUTION WOULD YIELD WIDESPREAD RAINFALL AMOUNTS IN EXCESS OF 2
INCHES...WITH SOME LOCALS OVER 4 INCHES.
CVKING
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1216 PM CDT MON APR 29 2013
VFR FLIGHT CONDITIONS WILL PREVAIL ACROSS THE AREA THROUGH TUESDAY
MORNING. THE ONLY POSSIBLE EXCEPTION WILL BE IN NORTHEAST MISSOURI
AND WEST CENTRAL ILLINOIS WHERE A PERIOD OF THUNDERSTORMS WILL BE
POSSIBLE THIS EVENING. LOW LEVEL WIND SHEAR IS LIKELY OVER CENTRAL
AND NORTHEAST MISSOURI AND WEST CENTRAL ILLINOIS TONIGHT...THE
WIND SHEAR POTENTIAL WILL DECREASE FURTHER EAST ACROSS EAST
CENTRAL MISSOURI AND SOUTHWEST ILLINOIS.
SPECIFICS FOR KSTL...
VFR FLIGHT CONDITIONS ARE EXPECTED TO PREVAIL AT LAMBERT THROUGH
TUESDAY. THERE`S STILL A CHANCE THAT THUNDERSTORMS WILL DEVELOP
OVER PARTS OF NORTHERN MISSOURI THIS EVENING. THIS MAY AFFECT SOME
OF THE NORTHERN/NORTHWESTERN ARRIVAL GATES...BUT NO DIRECT IMPACTS
TO THE TERMINAL ARE EXPECTED.
CARNEY
&&
.PRELIMINARY POINT TEMPS/POPS...
SAINT LOUIS 62 85 63 85 / 10 5 5 10
QUINCY 60 83 61 80 / 30 10 5 10
COLUMBIA 60 84 60 79 / 10 5 5 10
JEFFERSON CITY 61 84 60 81 / 10 5 5 10
SALEM 59 82 61 82 / 10 5 5 10
FARMINGTON 58 82 59 82 / 10 5 5 10
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
104 PM CDT MON APR 29 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 353 AM CDT MON APR 29 2013
A PACIFIC COLD FRONT...CURRENTLY ENTERING WRN WY...WILL MOVE THROUGH
THE FCST AREA TONIGHT. LOW PRESSURE AHEAD OF THE FRONT WILL DEEPEN
ACROSS WRN SD AND SEND ANOTHER SURGE OF WARM DRY AIR THROUGH THE
FCST AREA. THE RAP WHICH HAS BEEN VERIFYING WELL SUGGESTS 80S FOR
HIGHS TODAY MOST AREAS. DEW POINTS WILL FALL INTO THE 20S ONCE
AGAIN. THE CLEARING AREA ACROSS WY AND SD SHOULD MOVE EAST ACROSS
THE FCST AREA AND PROVIDE SUNNY SKIES TODAY.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 353 AM CDT MON APR 29 2013
FORECAST CONCERN FOR THE EXTENDED PERIOD REVOLVES AROUND
PRECIPITATION CHANCES MID-WEEK...SOME OF WHICH MAY FALL AS SNOW.
THE UNSETTLED PATTERN REMAINS THROUGH THE ENTIRE FORECAST
PERIOD...AS MODEL CONSENSUS SUGGESTS A STAGNATE PATTERN DEVELOPS
LATE WEEK...WITH A CUTOFF LOW AIMLESSLY MEANDERING THROUGH THE LOWER
MISSOURI VALLEY.
MODELS HAVE COME INTO GOOD AGREEMENT REGARDING THE TIMING OF THE
COLD FRONT...WHICH IS PROGGED TO PASS THROUGH THE FORECAST AREA
EARLY TUESDAY...THUS THE ATMOSPHERE WILL BE CHARACTERIZED BY POST
FRONTAL CONDITIONS...WITH STRONG CAA FILTERING SOUTH ACROSS THE CWA
THROUGH THE DAY ON TUESDAY. HIGHS WILL BE SOME 20-25 DEGREES
FAHRENHEIT COOLER THAN OBSERVED TODAY...WITH MOST READINGS REMAINING
THE 50S. ALSO OF NOTE...SHOWERS WILL BE ON THE INCREASE THROUGH THE
AFTERNOON AS A MID LEVEL SHORTWAVE WORKS IN CONJUNCTION WITH THE
RIGHT REAR ENTRANCE OF A STRONG UPPER JET MAX...PRECIPITATION WILL
SPREAD WEST TO EAST THROUGH THE AFTERNOON...AND SHOULD BECOME
FOCUSED ALONG AN AREA OF MIDLEVEL FRONTOGENETIC FORCING THAT APPEARS
TO BISECT THE CWA FROM SOUTHWEST TO NORTHEAST DURING THE AFTERNOON
HOURS /MAINLY THROUGH THE CENTRAL SANDHILLS/. PRECIPITATION CHANCES
BECOME MORE WIDESPREAD INTO THE EVENING HOURS AND OVERNIGHT AS DPVA
SPREADS EAST FROM ROCKIES ONTO THE NORTHERN HIGH PLAINS. ANALYSIS
OF THE 300-305K ISENTROPIC LAYER INDICATES SEVERAL HOURS /00-06Z
WEDNESDAY/ OF STRONG UPGLIDE TARGETING WESTERN AND NORTH CENTRAL
NEBRASKA...THEREAFTER DOWNGLIDE STARTS TO TAKE CONTROL WITH
CONDENSATION PRESSURE DEFICITS RAPIDLY RISING ABOVE 10MB...THUS CUT
BACK QPF AMOUNTS SOME ON WEDNESDAY WITH MOST LOCATIONS EXPECTING
LESS THAN A HALF OF AN INCH TOTAL QPF. ALSO TRIMMED POPS BACK INTO
THE LOW END CHANCE/SLIGHT CHANCE CATEGORY WEDNESDAY AFTERNOON AS
THE UPPER SUPPORT TRANSITIONS EAST WITH THE BEST UPGLIDE.
PROBLEMATIC TO THE FORECAST IS THE POTENTIAL FOR SNOW OR A RAIN/SNOW
MIX TUESDAY NIGHT AFTER MIDNIGHT THROUGH THE MORNING HOURS ON
WEDNESDAY...AS THE OPERATIONAL MODELS GENERATE AS MUCH AS FOUR TO
SIX INCHES ACROSS THE SANDHILLS...HOWEVER PROXIMITY SOUNDINGS
INDICATE FACTOR THAT MAY LIMIT OVERALL SNOW PRODUCTION AS THE
DENDRITIC LAYER IS CENTERED NEAR 500MB OVER SOUTHERN AND EASTERN
PORTIONS OF THE CWA /600-700 MB ACROSS THE NORTH AND
NORTHWEST/...AND GIVEN A RATHER SHORT PERIOD OF DEEP TROPOSPHERIC
MOISTURE...SNOW PRODUCTION MAY BE LIMITED. ANOTHER FACTOR AGAINST
ACCUMULATING SNOW IS THE RECENT WARM SPELL...WHICH HAS ALLOWED
GROUND TEMPERATURES TO CLIMB INTO THE 40S. SO FOR NOW WILL GO WITH
LIMITED TO NIL ACCUMULATIONS WITH THE IDEA THAT SUBSEQUENT
FORECASTS WILL HAVE A BETTER IDEA OF WHERE AND IF SNOW
ACCUMULATES.
A STRONG /~1040MB/ SURFACE HIGH WILL BUILD ACROSS THE HIGH PLAINS
EARLY ON THURSDAY AND REMAIN THROUGH FRIDAY MORNING...FROST AND/OR
FREEZE CONDITIONS WILL BE POSSIBLE.
THE UPPER PATTERN BECOMES STALE BY LATE WEEK WITH A CUTOFF LOW
FORMING AND REMAINING SOMEWHERE IN THE VICINITY OF THE LOWER
MISSOURI VALLEY. TEMPERATURES HEADING INTO THE WEEKEND SHOULD
SLOWLY MODERATE ACROSS OUR WESTERN ZONES...WITH THE
EAST...INFLUENCED BY THE UPPER LOW...REMAINING RATHER COOL. THE
LONGER RANGE SOLUTIONS CONTINUE TO INDICATE WRAP AROUND QPF POSSIBLY
AS FAR WEST AS HIGHWAY 61 THROUGH THE WEEKEND. CONFIDENCE IN STALE
PATTERNS USUALLY IS FAIRLY LOW...THUS WON/T MAKE ANY WHOLESALE
CHANGES TO THE EXTENDED PROCEDURE FOR NOW.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 102 PM CDT MON APR 29 2013
COLD FRONT WILL MOVE ACROSS THE AREA TOMORROW MORNING. UNTIL THEN
SOUTH TO SOUTHWEST WINDS...GUSTING TO 20 TO 25 KTS THIS AFTERNOON
BENEATH VFR SKIES. CLEAR SKIES WILL SEE SOME HIGH CLOUDS MOVE IN
FROM THE NW FOR THE AFTERNOON. INCREASING MID HIGH CLOUDS AHEAD OF
THE FRONT OVERNIGHT. LIMITED MOISTURE SO FRONTAL PASSAGE SHOULD BE
DRY...HOWEVER WILL SEE A DRAMATIC SWITCH TO N/NNW WINDS. AS THE
FRONT CONTINUES TO PUSH TO THE SOUTHEAST...WINDS WILL
INCREASE...GUSTING TO 15 TO 25 KTS BY LATE MORNING.
&&
.FIRE WEATHER...
ISSUED AT 353 AM CDT MON APR 29 2013
LOW PRESSURE DEEPENS ACROSS WRN SD THIS AFTERNOON TO AROUND 990 MB.
THIS SEND ANOTHER SURGE OF WEST/SOUTHWEST WINDS AND VERY DRY AIR
THROUGH THE PANHANDLE AND INTO NCNTL NEB. WINDS SHOULD INCREASE TO
15 TO 25 MPH WITH RH BETWEEN 10 AND 15 PERCENT. GREEN UP IS UNDERWAY
SO FUEL STATUS IS QUESTIONABLE FOR CRITICAL FIRE DANGER ACROSS NWRN
NEB. NO RED FLAG WARNING WILL BE ISSUED.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...JACOBS
AVIATION...MASEK
FIRE WEATHER...CDC
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
636 AM CDT MON APR 29 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 353 AM CDT MON APR 29 2013
A PACIFIC COLD FRONT...CURRENTLY ENTERING WRN WY...WILL MOVE THROUGH
THE FCST AREA TONIGHT. LOW PRESSURE AHEAD OF THE FRONT WILL DEEPEN
ACROSS WRN SD AND SEND ANOTHER SURGE OF WARM DRY AIR THROUGH THE
FCST AREA. THE RAP WHICH HAS BEEN VERIFYING WELL SUGGESTS 80S FOR
HIGHS TODAY MOST AREAS. DEW POINTS WILL FALL INTO THE 20S ONCE
AGAIN. THE CLEARING AREA ACROSS WY AND SD SHOULD MOVE EAST ACROSS
THE FCST AREA AND PROVIDE SUNNY SKIES TODAY.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 353 AM CDT MON APR 29 2013
FORECAST CONCERN FOR THE EXTENDED PERIOD REVOLVES AROUND
PRECIPITATION CHANCES MID-WEEK...SOME OF WHICH MAY FALL AS SNOW.
THE UNSETTLED PATTERN REMAINS THROUGH THE ENTIRE FORECAST
PERIOD...AS MODEL CONSENSUS SUGGESTS A STAGNATE PATTERN DEVELOPS
LATE WEEK...WITH A CUTOFF LOW AIMLESSLY MEANDERING THROUGH THE LOWER
MISSOURI VALLEY.
MODELS HAVE COME INTO GOOD AGREEMENT REGARDING THE TIMING OF THE
COLD FRONT...WHICH IS PROGGED TO PASS THROUGH THE FORECAST AREA
EARLY TUESDAY...THUS THE ATMOSPHERE WILL BE CHARACTERIZED BY POST
FRONTAL CONDITIONS...WITH STRONG CAA FILTERING SOUTH ACROSS THE CWA
THROUGH THE DAY ON TUESDAY. HIGHS WILL BE SOME 20-25 DEGREES
FAHRENHEIT COOLER THAN OBSERVED TODAY...WITH MOST READINGS REMAINING
THE 50S. ALSO OF NOTE...SHOWERS WILL BE ON THE INCREASE THROUGH THE
AFTERNOON AS A MID LEVEL SHORTWAVE WORKS IN CONJUNCTION WITH THE
RIGHT REAR ENTRANCE OF A STRONG UPPER JET MAX...PRECIPITATION WILL
SPREAD WEST TO EAST THROUGH THE AFTERNOON...AND SHOULD BECOME
FOCUSED ALONG AN AREA OF MIDLEVEL FRONTOGENETIC FORCING THAT APPEARS
TO BISECT THE CWA FROM SOUTHWEST TO NORTHEAST DURING THE AFTERNOON
HOURS /MAINLY THROUGH THE CENTRAL SANDHILLS/. PRECIPITATION CHANCES
BECOME MORE WIDESPREAD INTO THE EVENING HOURS AND OVERNIGHT AS DPVA
SPREADS EAST FROM ROCKIES ONTO THE NORTHERN HIGH PLAINS. ANALYSIS
OF THE 300-305K ISENTROPIC LAYER INDICATES SEVERAL HOURS /00-06Z
WEDNESDAY/ OF STRONG UPGLIDE TARGETING WESTERN AND NORTH CENTRAL
NEBRASKA...THEREAFTER DOWNGLIDE STARTS TO TAKE CONTROL WITH
CONDENSATION PRESSURE DEFICITS RAPIDLY RISING ABOVE 10MB...THUS CUT
BACK QPF AMOUNTS SOME ON WEDNESDAY WITH MOST LOCATIONS EXPECTING
LESS THAN A HALF OF AN INCH TOTAL QPF. ALSO TRIMMED POPS BACK INTO
THE LOW END CHANCE/SLIGHT CHANCE CATEGORY WEDNESDAY AFTERNOON AS
THE UPPER SUPPORT TRANSITIONS EAST WITH THE BEST UPGLIDE.
PROBLEMATIC TO THE FORECAST IS THE POTENTIAL FOR SNOW OR A RAIN/SNOW
MIX TUESDAY NIGHT AFTER MIDNIGHT THROUGH THE MORNING HOURS ON
WEDNESDAY...AS THE OPERATIONAL MODELS GENERATE AS MUCH AS FOUR TO
SIX INCHES ACROSS THE SANDHILLS...HOWEVER PROXIMITY SOUNDINGS
INDICATE FACTOR THAT MAY LIMIT OVERALL SNOW PRODUCTION AS THE
DENDRITIC LAYER IS CENTERED NEAR 500MB OVER SOUTHERN AND EASTERN
PORTIONS OF THE CWA /600-700 MB ACROSS THE NORTH AND
NORTHWEST/...AND GIVEN A RATHER SHORT PERIOD OF DEEP TROPOSPHERIC
MOISTURE...SNOW PRODUCTION MAY BE LIMITED. ANOTHER FACTOR AGAINST
ACCUMULATING SNOW IS THE RECENT WARM SPELL...WHICH HAS ALLOWED
GROUND TEMPERATURES TO CLIMB INTO THE 40S. SO FOR NOW WILL GO WITH
LIMITED TO NIL ACCUMULATIONS WITH THE IDEA THAT SUBSEQUENT
FORECASTS WILL HAVE A BETTER IDEA OF WHERE AND IF SNOW
ACCUMULATES.
A STRONG /~1040MB/ SURFACE HIGH WILL BUILD ACROSS THE HIGH PLAINS
EARLY ON THURSDAY AND REMAIN THROUGH FRIDAY MORNING...FROST AND/OR
FREEZE CONDITIONS WILL BE POSSIBLE.
THE UPPER PATTERN BECOMES STALE BY LATE WEEK WITH A CUTOFF LOW
FORMING AND REMAINING SOMEWHERE IN THE VICINITY OF THE LOWER
MISSOURI VALLEY. TEMPERATURES HEADING INTO THE WEEKEND SHOULD
SLOWLY MODERATE ACROSS OUR WESTERN ZONES...WITH THE
EAST...INFLUENCED BY THE UPPER LOW...REMAINING RATHER COOL. THE
LONGER RANGE SOLUTIONS CONTINUE TO INDICATE WRAP AROUND QPF POSSIBLY
AS FAR WEST AS HIGHWAY 61 THROUGH THE WEEKEND. CONFIDENCE IN STALE
PATTERNS USUALLY IS FAIRLY LOW...THUS WON/T MAKE ANY WHOLESALE
CHANGES TO THE EXTENDED PROCEDURE FOR NOW.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 633 AM CDT MON APR 29 2013
VFR IS EXPECTED ALL AREAS THROUGH 06Z TONIGHT. THEREAFTER...A COLD
FRONT WILL ENTER NRN NEB...POSSIBLY PRODUCING A BAND OF MVFR CIGS
ALONG THE FRONT. GIVEN THE VERY DRY CONDITIONS ONGOING...THE
PROBABILITY OF THIS OCCURRING IS LOW.
&&
.FIRE WEATHER...
ISSUED AT 353 AM CDT MON APR 29 2013
LOW PRESSURE DEEPENS ACROSS WRN SD THIS AFTERNOON TO AROUND 990 MB.
THIS SEND ANOTHER SURGE OF WEST/SOUTHWEST WINDS AND VERY DRY AIR
THROUGH THE PANHANDLE AND INTO NCNTL NEB. WINDS SHOULD INCREASE TO
15 TO 25 MPH WITH RH BETWEEN 10 AND 15 PERCENT. GREEN UP IS UNDERWAY
SO FUEL STATUS IS QUESTIONABLE FOR CRITICAL FIRE DANGER ACROSS NWRN
NEB. NO RED FLAG WARNING WILL BE ISSUED.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...JACOBS
AVIATION...CDC
FIRE WEATHER...CDC
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
354 AM CDT MON APR 29 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 353 AM CDT MON APR 29 2013
A PACIFIC COLD FRONT...CURRENTLY ENTERING WRN WY...WILL MOVE THROUGH
THE FCST AREA TONIGHT. LOW PRESSURE AHEAD OF THE FRONT WILL DEEPEN
ACROSS WRN SD AND SEND ANOTHER SURGE OF WARM DRY AIR THROUGH THE
FCST AREA. THE RAP WHICH HAS BEEN VERIFYING WELL SUGGESTS 80S FOR
HIGHS TODAY MOST AREAS. DEW POINTS WILL FALL INTO THE 20S ONCE
AGAIN. THE CLEARING AREA ACROSS WY AND SD SHOULD MOVE EAST ACROSS
THE FCST AREA AND PROVIDE SUNNY SKIES TODAY.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 353 AM CDT MON APR 29 2013
FORECAST CONCERN FOR THE EXTENDED PERIOD REVOLVES AROUND
PRECIPITATION CHANCES MID-WEEK...SOME OF WHICH MAY FALL AS SNOW.
THE UNSETTLED PATTERN REMAINS THROUGH THE ENTIRE FORECAST
PERIOD...AS MODEL CONSENSUS SUGGESTS A STAGNATE PATTERN DEVELOPS
LATE WEEK...WITH A CUTOFF LOW AIMLESSLY MEANDERING THROUGH THE LOWER
MISSOURI VALLEY.
MODELS HAVE COME INTO GOOD AGREEMENT REGARDING THE TIMING OF THE
COLD FRONT...WHICH IS PROGGED TO PASS THROUGH THE FORECAST AREA
EARLY TUESDAY...THUS THE ATMOSPHERE WILL BE CHARACTERIZED BY POST
FRONTAL CONDITIONS...WITH STRONG CAA FILTERING SOUTH ACROSS THE CWA
THROUGH THE DAY ON TUESDAY. HIGHS WILL BE SOME 20-25 DEGREES
FAHRENHEIT COOLER THAN OBSERVED TODAY...WITH MOST READINGS REMAINING
THE 50S. ALSO OF NOTE...SHOWERS WILL BE ON THE INCREASE THROUGH THE
AFTERNOON AS A MID LEVEL SHORTWAVE WORKS IN CONJUNCTION WITH THE
RIGHT REAR ENTRANCE OF A STRONG UPPER JET MAX...PRECIPITATION WILL
SPREAD WEST TO EAST THROUGH THE AFTERNOON...AND SHOULD BECOME
FOCUSED ALONG AN AREA OF MIDLEVEL FRONTOGENETIC FORCING THAT APPEARS
TO BISECT THE CWA FROM SOUTHWEST TO NORTHEAST DURING THE AFTERNOON
HOURS /MAINLY THROUGH THE CENTRAL SANDHILLS/. PRECIPITATION CHANCES
BECOME MORE WIDESPREAD INTO THE EVENING HOURS AND OVERNIGHT AS DPVA
SPREADS EAST FROM ROCKIES ONTO THE NORTHERN HIGH PLAINS. ANALYSIS
OF THE 300-305K ISENTROPIC LAYER INDICATES SEVERAL HOURS /00-06Z
WEDNESDAY/ OF STRONG UPGLIDE TARGETING WESTERN AND NORTH CENTRAL
NEBRASKA...THEREAFTER DOWNGLIDE STARTS TO TAKE CONTROL WITH
CONDENSATION PRESSURE DEFICITS RAPIDLY RISING ABOVE 10MB...THUS CUT
BACK QPF AMOUNTS SOME ON WEDNESDAY WITH MOST LOCATIONS EXPECTING
LESS THAN A HALF OF AN INCH TOTAL QPF. ALSO TRIMMED POPS BACK INTO
THE LOW END CHANCE/SLIGHT CHANCE CATEGORY WEDNESDAY AFTERNOON AS
THE UPPER SUPPORT TRANSITIONS EAST WITH THE BEST UPGLIDE.
PROBLEMATIC TO THE FORECAST IS THE POTENTIAL FOR SNOW OR A RAIN/SNOW
MIX TUESDAY NIGHT AFTER MIDNIGHT THROUGH THE MORNING HOURS ON
WEDNESDAY...AS THE OPERATIONAL MODELS GENERATE AS MUCH AS FOUR TO
SIX INCHES ACROSS THE SANDHILLS...HOWEVER PROXIMITY SOUNDINGS
INDICATE FACTOR THAT MAY LIMIT OVERALL SNOW PRODUCTION AS THE
DENDRITIC LAYER IS CENTERED NEAR 500MB OVER SOUTHERN AND EASTERN
PORTIONS OF THE CWA /600-700 MB ACROSS THE NORTH AND
NORTHWEST/...AND GIVEN A RATHER SHORT PERIOD OF DEEP TROPOSPHERIC
MOISTURE...SNOW PRODUCTION MAY BE LIMITED. ANOTHER FACTOR AGAINST
ACCUMULATING SNOW IS THE RECENT WARM SPELL...WHICH HAS ALLOWED
GROUND TEMPERATURES TO CLIMB INTO THE 40S. SO FOR NOW WILL GO WITH
LIMITED TO NIL ACCUMULATIONS WITH THE IDEA THAT SUBSEQUENT
FORECASTS WILL HAVE A BETTER IDEA OF WHERE AND IF SNOW
ACCUMULATES.
A STRONG /~1040MB/ SURFACE HIGH WILL BUILD ACROSS THE HIGH PLAINS
EARLY ON THURSDAY AND REMAIN THROUGH FRIDAY MORNING...FROST AND/OR
FREEZE CONDITIONS WILL BE POSSIBLE.
THE UPPER PATTERN BECOMES STALE BY LATE WEEK WITH A CUTOFF LOW
FORMING AND REMAINING SOMEWHERE IN THE VICINITY OF THE LOWER
MISSOURI VALLEY. TEMPERATURES HEADING INTO THE WEEKEND SHOULD
SLOWLY MODERATE ACROSS OUR WESTERN ZONES...WITH THE
EAST...INFLUENCED BY THE UPPER LOW...REMAINING RATHER COOL. THE
LONGER RANGE SOLUTIONS CONTINUE TO INDICATE WRAP AROUND QPF POSSIBLY
AS FAR WEST AS HIGHWAY 61 THROUGH THE WEEKEND. CONFIDENCE IN STALE
PATTERNS USUALLY IS FAIRLY LOW...THUS WON/T MAKE ANY WHOLESALE
CHANGES TO THE EXTENDED PROCEDURE FOR NOW.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 100 PM CDT SUN APR 28 2013
ANOTHER HOT DAY WITH VFR CONDITIONS EXPECTED THIS AFTERNOON. A
WEAK COLD FRONT WILL CAUSE A SLIGHT WIND SHIFT FROM THE
WEST/NORTHWEST TO THE NORTH. WINDS SPEEDS WILL BE SIMILAR BOTH
AHEAD AND BEHIND THE FRONT...GUSTING TO 20 TO 25 KTS. A WEAK
DISTURBANCE WILL MOVE ACROSS THE AREA TONIGHT...AND SHOULD BE
ENOUGH TO SPARK SOME ISOLD/SCT SHOWERS AND THUNDERSTORMS...MAINLY
TO IMPACT NORTHERN NEB. FURTHER SOUTH AN INCREASE OF MID/HIGH
CLOUDS...HOWEVER DRIER LOWER LEVEL ATMOSPHERE SHOULD PREVENT ANY
DEVELOP. SYSTEM MOVES THROUGH QUICKLY WITH VFR AND DRY CONDITIONS
FOR MONDAY...WINDS DO BECOME SOUTHERLY DURING THE LATE MORNING
HOURS.
&&
.FIRE WEATHER...
ISSUED AT 353 AM CDT MON APR 29 2013
LOW PRESSURE DEEPENS ACROSS WRN SD THIS AFTERNOON TO AROUND 990 MB.
THIS SEND ANOTHER SURGE OF WEST/SOUTHWEST WINDS AND VERY DRY AIR
THROUGH THE PANHANDLE AND INTO NCNTL NEB. WINDS SHOULD INCREASE TO
15 TO 25 MPH WITH RH BETWEEN 10 AND 15 PERCENT. GREEN UP IS UNDERWAY
SO FUEL STATUS IS QUESTIONABLE FOR CRITICAL FIRE DANGER ACROSS NWRN
NEB. NO RED FLAG WARNING WILL BE ISSUED.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...JACOBS
AVIATION...CDC
FIRE WEATHER...CDC
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1254 AM CDT MON APR 29 2013
.UPDATE...
ISSUED AT 1251 AM CDT MON APR 29 2013
MINOR ADJUSTMENTS WERE MADE FOR THE OVERNIGHT AS THE FORECAST IS
LARGELY ON TRACK. DEWPOINTS ARE NOT REBOUNDING QUITE AS QUICKLY AS
ANTICIPATED FOR SOME SPOTS OF THE CWA...SO MORE ADJUSTMENTS MAY BE
NEEDED.
UPDATE ISSUED AT 927 PM CDT SUN APR 28 2013
AS OF 02Z RADAR DATA FROM KUEX INDICATES NOTHING IN THE WAY OF
PRECIPITATION OVER OUR CWA. WITH THE LOSS OF DIABATIC HEATING FOR
THE DAY AND POTENTIAL INSTABILITY RAPIDLY DROPPING OFF...PER THE
SPC MESO-ANALYSIS PAGE...THE CHANCES OF CONVECTIVE ACTIVITY BEING
REALIZED ACROSS OUR CWA THIS EVENING ARE QUICKLY DWINDLING. GIVEN
ALL THIS...WENT AHEAD AND PULLED THE ~20% POPS WE PREVIOUSLY HAD
GOING ACROSS OUR NORTHEASTERN CWA THROUGH THIS EVENING. POPS
REMAIN INTACT ACROSS OUR NORTHEAST STARTING AFTER 06Z AS THE
SUBTLE MID LEVEL SHORT WAVE ADVANCES OVER PORTIONS OF THE
REGION...BUT CONVECTIVE ACTIVITY IS NOT CURRENTLY ANTICIPATED WITH
ANY PRECIPITATION AFTER 06Z. THE REMAINDER OF THE FORECAST REMAINS
IN GREAT SHAPE...WITH ONLY SUBTLE CHANGES MADE TO HOURLY
TEMPERATURE...WIND...AND DEWPOINT GRIDS TO BETTER REFLECT CURRENT
OBSERVATIONS.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 240 PM CDT SUN APR 28 2013
PRIMARY FORECAST CONCERN WILL BE SMALL CHANCES FOR THUNDERSTORMS
LATE THIS AFTERNOON AND EVENING IN THE NORTHEAST PART OF THE CWA
AND THEN ANOTHER SMALL CHANCE FOR SHOWERS IN THE NORTH PART OF THE
CWA OVERNIGHT.
UPPER AIR ANALYSIS AND CURRENT WATER VAPOR IMAGERY SHOW AN UPPER
LEVEL TROUGH MOVING ACROSS THE EASTERN THIRD OF THE COUNTRY WHILE
MORE OF A ZONAL FLOW IS NOTED FROM THE PACIFIC NW INTO THE CENTRAL
PLAINS. THERE ARE A COUPLE OF WEAK SHORT WAVES TO DEAL
WITH...ESPECIALLY ONE MOVING INTO MONTANA WHICH COULD PROVIDE SOME
FORCING ACROSS THE NORTHERN PART OF OUR CWA LATER TONIGHT.
AT THE SURFACE...A TROUGH OF LOW PRESSURE WAS JUST MOVING INTO THE
FAR WESTERN PART OF THE CWA BY 19Z. TEMPERATURES HAVE CLIMBED
STEADILY TODAY AND MOST LOCATIONS SHOULD HIT THE 80S BEFORE THE
AFTERNOON IS OUT. DEW POINTS RANGE FROM THE MID TO UPPER 40S EAST OF
THE SURFACE TROUGH...IN THE MID 30S ALONG THE TROUGH AXIS...AND THEN
DIPPING INTO THE MID 20S 50 TO 100 MILES BEHIND THE TROUGH.
REGARDING FIRE WEATHER CONCERNS...RELATIVE HUMIDITIES HAVE FALLEN
NEAR OR BELOW 20 PERCENT IN THE WEST...BUT WINDS SHOULD STAY BELOW
20 MPH IN THAT PART OF OUR CWA AS THE TROUGH AXIS LIES OVER THAT
AREA. BY THE TIME THE WINDS PICK UP AGAIN FROM THE NW...WE SHOULD BE
A FEW HOURS PAST MAX HEATING.
VARIOUS SHORT RANGE MODELS SHOWING SOME DECENT INSTABILITY AHEAD OF
THE SURFACE TROUGH WHICH COULD TRIGGER CONVECTION LATER THIS
AFTERNOON. BOTH THE HRRR AND THE 4KM WRF SHOWING TSTM DEVELOPMENT IN
THE NORTHEAST PART OF THE CWA FROM ROUGHLY 5 PM THROUGH 10 PM. WHILE
BETTER CHANCES SEEM TO BE JUST A LITTLE FURTHER NORTHEAST THAN OUR
CWA...WILL CONTINUE WITH AT LEAST A SLIGHT CHANCE IN OUR NORTHEAST
AS WE COULD CERTAINLY GET CLIPPED.
THE SHORTWAVE NOTED ABOVE SHOULD HAVE MORE OF AN IMPACT AFTER
MIDNIGHT AND CONTINUED THE CHANCE OF SHOWERS MAINLY IN THE
NORTHEASTERN HALF OF THE CWA. FORCING AND MOISTURE NOT OVERLY
IMPRESSIVE AND WILL KEEP POPS FAIRLY LOW. INSTABILITY ALSO DROPS OFF
QUITE A BIT SO WILL KEEP THUNDER MENTION OUT AFTER MIDNIGHT.
QUIET WEATHER EXPECTED ON MONDAY AS WE AWAIT THE APPROACH OF THE
NEXT SYSTEM UPSTREAM. WITH EASTERLY FLOW AT SURFACE...HIGH
TEMPERATURES SHOULD BE JUST A LITTLE BIT COOLER THAN WHAT WE ARE
SEEING TODAY...BUT ALL IN ALL STILL NOT BAD.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 240 PM CDT SUN APR 28 2013
THE WEATHER PATTERN WILL UNDERGO CHANGES DURING THE EXTENDED PERIODS
WITH A TREND TO COOLER SPRING CONDITIONS.
ON MONDAY NIGHT AN UPPER TROUGH DIGS SOUTH ACROSS THE
NORTHWEST/NORTH CENTRAL TIER STATES AND A SFC COLD FRONTAL BOUNDARY
PUSHES SOUTH FM THE DAKOTAS...AND IS EXPECTED TO STRETCH FM
ROUGHLY KOMA TO KPHG TO SOUTH OF KGLD BY 12Z TUESDAY. WITH FRONT
CROSSING MUCH OF OUR NEB CWA OVERNIGHT...CONSIDERED SOME LOW POPS
TOWARD TUESDAY MORNING BUT CHCS APPEAR HIT OR MISS AND WILL CARRY
SILENT POPS FOR NOW. IN GENERAL...MODELS HAVE CONTINUED TO TREND
FASTER WITH FROPA...WITH THE NAM REMAINING FASTER THAN GFS. THE
FARTHER SOUTH FRONTAL POSITION NEAR THE NEB/KS STATELINE OR IN
NORTHERN KANSAS PLACES CHCS FOR AFTN CONVECTION FARTHER SOUTH AS
WELL. DEPENDING ON TIMING/FRONTAL POSITION THERE STILL APPEARS TO
BE A WINDOW OF OPPORTUNITY...ALBEIT A SHRINKING WINDOW...FOR
POTENTIALLY A STRONG/SEVERE TSTMS IN THE LATE AFTN/EVE FOR OUR
SOUTHEAST ZONES. SOME PRESENCE OF ELEVATED INSTABILITY IS
MAINTAINED INTO THE FIRST PART OF THE NIGHT TUESDAY NIGHT WHICH
SHIFTS SOUTH BY WEDNESDAY MORNING. OVERALL PCPN CHCS INCREASE OVERNIGHT
TUESDAY NIGHT ACROSS OUR ENTIRE CWA IN INCREASING ISENTROPIC LIFT
AHEAD OF THE UPPER TROUGH MOVING ONTO THE CENTRAL PLAINS AND IN
PRESENCE OF STRONG MID LEVEL FRONTOGENESIS. MUCH COLDER AIR
ADVECTS SOUTH BEHIND THE FRONTAL BOUNDARY AND THE R/S LINE ACROSS
WESTERN NEBRASKA LOOKS TO EDGE CLOSE TO OUR NW CWA TOWARDS
WEDNESDAY MORNING.
WEDNESDAY IS SHAPING UP TO BE A COLD...WET...BREEZY/WINDY DAY UNDER
INFLUENCE OF UPPER TROUGH MOVING IN WITH THE BETTER CHCS FOR PCPN
EXPECTED IN THE FIRST PART OF THE DAY BEFORE DRIER AIR ADVECTS IN
FOLLOWING MID LEVEL TROUGH...BUT THIS WILL BE DEPENDENT UPON
SYSTEMN TIMING WITH GFS MORE PROGRESSIVE THAN ECMWF.
MODELS CONTINUE TO DEVIATE ON WHERE UPPER LOW WILL CLOSE OFF
THURS NIGHT/FRI DUE TO A BLOCKING RIDGE TO THE EAST. 24HRS AGO
THE 12Z MODELS CLOSED THE LOW ACROSS THE CENTRAL PLAINS...THEN
THE 00Z SUNDAY RUN OF MODELS CLOSED THE LOW IN EASTERN KS/SOUTHERN
MISSOURI...AND NOW THE 12Z GFS RUN CLOSES THE LOW EAST OF THE
MISSOURI RIVER IN IOWA WITH THE POTENTIAL FOR A CUTOFF SYSTEM TO
LIFT AND RETROGRADE TOWARD THE END OF THE WORKWEEK AND INTO THE
FIRST PART OF NEXT WEEKEND. THE 12Z ECMWF IS A LITTLE MORE SIMILAR
TO ITS PREVIOUS RUN INITIALLY WITH THE SYSTEM CLOSING OFF IN
EASTERN KS WITH THE CUTOFF UPPER LOW MEANDERING ACROSS MISSOURI
THRU THE WEEKEND. PCPN CHCS WILL BE DEPENDENT UPON THE UPPER LOW
PRESSURE SYSTEM POSITION AND IT IS JUST TOO EARLY TO PINPOINT THE
BEST CHCS/TIMING JUST YET GIVEN THE VARYING MODEL SOLUTIONS AND
DID NOT DEVIATE MUCH FROM THE EXTENDED INIT. UNDER THE INFLUENCE
OF THE UPPER LOW/TROUGH PATTERN...TEMPERATURES WILL REMAIN COOL WITH HIGHS
MAINLY 50S...AND LOWS IN THE 30S...ALTHOUGH READINGS COULD RECOVER
SOME IF LOW KICKS OUT TOWARD DAY 7. WITH LOWS IN THE 30S WILL NEED
TO CLOSELY MONITOR POTENTIAL FOR FROST/FREEZE AS SPRING HEADLINES
FOR THIS BEGIN MAY 1.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1251 AM CDT MON APR 29 2013
WIND SPEED SHOULD BE A BIT ELEVATED FROM THE NORTHEAST BEHIND A
COLD FRONT...WHICH SEEMS TO BE FRONTOLYTIC. WIND SHOULD BECOME
NEARLY CALM BY MID-DAY MONDAY AS A TRANSITION TO A SOUTH WIND
OCCURS AS A LEE SIDE TROUGH DEVELOPS TO THE WEST. MAINLY MID-LEVEL
CLOUDINESS IS EXPECTED WITH LOW-LEVELS REMAINING DRY.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...HEINLEIN
SHORT TERM...EWALD
LONG TERM...FAY
AVIATION...HEINLEIN
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
158 PM EDT MON APR 29 2013
.SYNOPSIS...
UPPER LEVEL LOW PRESSURE OVER THE EASTERN PART OF THE AREA WILL
WEAKEN AND MOVE NORTHEAST TODAY. HIGH PRESSURE WILL BUILD OVER THE
AREA TUESDAY INTO WEDNESDAY AND REMAIN IN PLACE INTO FRIDAY BEFORE
WEAKENING AND MOVING EAST. A LOW SHOULD APPROACH THE AREA FROM THE
WEST NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LATEST HRRR MODEL SHOWS WEAK LINE OF SHOWERS EXPECTED TO CONTINUE
OVER NORTHEAST OHIO INTO NORTHWEST PENNSYLVANIA EARLY THIS
AFTERNOON. THIS IS ASSOCIATED WITH SURFACE TROUGH THAT WILL
EVENTUALLY PUSH EAST AND OUT OF THE REGION. WILL KEEP THE CHANCE
OF SHOWERS GOING IN THE EAST THROUGH THE AFTERNOON. IN THE
WEST...SOME CLEARING IS TRYING TO PUSH INTO NORTHWEST OHIO AND
THIS SHOULD SUPPORT SOME SUNSHINE THROUGH THE AFTERNOON.
ELSEWHERE...CLOUDS SHOULD HOLD IN WITH A FEW BREAKS IN THE
OVERCAST. DUE TO CLOUDS MOST AREAS AND SHOWERS EAST...WILL GO
AHEAD AND BUMP TEMPERATURES DOWN A FEW DEGREES. I STILL THINK THE
EAST WILL RECOVER SINCE WE STILL HAVE A FAIR AMOUNT OF DAYLIGHT
LEFT THIS AFTERNOON AND EVENING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
MID AND UPPER RIDGING STARTING TO BUILD IN TONIGHT SHOULD CAUSE MOST
OF THE SHRA TO END DURING THE EVENING. LIGHT SOUTH WINDS WILL LIKELY
ALLOW FOR MORE PATCHY FOG TO DEVELOP TONIGHT.
THE MODELS CONTINUE TO SHOW THE HIGH TO THE NE HOLDING MOISTURE
AROUND 850 MB OVER THE EAST HALF OF THE CWA ON TUE AND EVEN PRODUCE
SOME LIGHT PRECIP. HAVING A HARD TIME SEEING TOO MUCH CONVECTION
DEVELOP DUE TO THE UPPER RIDGING SO WILL KEEP POPS TO ONLY A SLIGHT
CHANCE OR LESS.
SIMILAR SITUATION ON WED BUT THE MOISTURE AROUND 850 MB NOW SPREAD
OVER MOST OF THE AREA. NAM AGAIN HAS SOME LIGHT PRECIP OVER THE
CENTRAL PART OF THE CWA. GUIDANCE POPS LOW AND ONGOING FORECAST HAS
BEEN DRY SO WILL MAINTAIN THE CONTINUITY AND KEEP POPS AT 14% OR
LESS.
UPPER TROUGH MOVES EAST TO NEAR THE MS RIVER ON THU INDUCING A
SURFACE LOW TO NOSE NE INTO INDIANA BY LATER IN THE DAY. UPPER
RIDGING SHOULD HOLD OFF THE PRECIP IN THE EAST. THE FAR WEST LOOKS
TO HAVE TOO MUCH MOISTURE TO WORK WITH ALONG WITH A LITTLE BETTER
DYNAMICS SO SOME CONVECTION CAN`T BE RULED OUT. THUS WILL ADD A
SLIGHT CHANCE POP IN FOR THAT AREA WHICH WILL ALSO COLLABORATE
BETTER WITH BORDERING FORECASTS.
TEMPS SHOULD WARM TUE INTO WED THEN STAY ABOVE NORMAL FOR THU.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
LONG TERM BEGINS ON FRIDAY WITH THE GFS AND ECMWF FAIRLY CONSISTENT
IN THE PLACEMENT OF WHAT WILL BECOME A CUTOFF UPPER LOW OVER THE
NATIONS MID SECTION. 12Z FRIDAY THE MODELS HAVE THE LOW NEAR KANSAS
CITY WHILE AN UPPER HIGH WILL BE OVER PA AND NY INFLUENCING THE AREA
FROM THE EAST. MEANWHILE WESTERN COUNTIES WILL HAVE INCREASED
MOISTURE FROM THE FLOW AROUND THE LOW. SYSTEMS REMAIN NEARLY
STATIONARY THROUGH SUNDAY THEN BEGIN TO MOVE EAST SUNDAY NIGHT AND
MONDAY. IN GENERAL WILL HAVE CHANCE POPS FOR SHOWERS OR
THUNDERSTORMS WEST WITH MORE CLOUD COVER VS EAST. SATURDAY NIGHT AND
SUNDAY WILL HAVE CHANCE POPS FOR THE ENTIRE AREA AS MOISTURE SHIFTS
EAST. TEMPS MILD WITH NORMAL TO A FEW DEGREES ABOVE NORMAL TEMPS
EXPECTED.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
SCATTERED SHOWERS CONTINUE TO AFFECT PORTIONS OF NORTHEAST OHIO AND
NORTHWEST PENNSYLVANIA THIS AFTERNOON AS A WEAK SURFACE TROUGH MOVES
EAST OF THE AREA. EASTERN TAF SITES ARE A MIX OF MVFR AND VFR THIS
AFTERNOON...AND WILL LIKELY HOVER AROUND THIS THRESHOLD FOR THE NEXT
SIX HOURS. DRIER AIR IS BUILDING IN BEHIND THE TROUGH...BUT LOW
LEVEL MOISTURE REMAINS. THE LOW LEVEL MOISTURE COMBINED WITH LIGHT
WINDS WILL HELP IN THE DEVELOPMENT OF FOG AND LOW LEVEL STRATUS IN
THE OVERNIGHT TO EARLY MORNING HOURS. MVFR TO IFR VISIBILITIES ARE
EXPECTED WITH THE FOG...ESPECIALLY AFTER 08Z. FOG WILL DISSIPATE BY
ABOUT 13Z AS THE SURFACE BEGINS TO HEAT. VFR CEILINGS WILL PERSIST
THROUGH THE REST OF THE TAF PERIOD.
.OUTLOOK...NON-VFR POSSIBLE TUESDAY MORNING...THURSDAY MORNING AND
FRIDAY MORNING.
&&
.MARINE...
FOR TODAY LOOKING FOR SOUTH TO SOUTHWEST FLOW BEHIND A WEAK SURFACE
TROF MOVING ACROSS THE REGION. TONIGHT THROUGH FRIDAY...EXPECTING
GENERALLY SOUTH TO SOUTHEAST FLOW FOR MUCH OF THE PERIOD WITH HIGH
PRESSURE TO OUR EAST AND LOW PRESSURE WEST OF THE AREA. NO
HEADLINES ANTICIPATED.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...ADAMS
NEAR TERM...LOMBARDY
SHORT TERM...ADAMS
LONG TERM...TK
AVIATION...YEAGER
MARINE...TK
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1232 PM EDT MON APR 29 2013
.SYNOPSIS...
UPPER LEVEL LOW PRESSURE OVER THE EASTERN PART OF THE AREA WILL
WEAKEN AND MOVE NORTHEAST TODAY. HIGH PRESSURE WILL BUILD OVER THE
AREA TUESDAY INTO WEDNESDAY AND REMAIN IN PLACE INTO FRIDAY BEFORE
WEAKENING AND MOVING EAST. A LOW SHOULD APPROACH THE AREA FROM THE
WEST NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LATEST HRRR MODEL SHOWS WEAK LINE OF SHOWERS EXPECTED TO CONTINUE
OVER NORTHEAST OHIO INTO NORTHWEST PENNSYLVANIA EARLY THIS
AFTERNOON. THIS IS ASSOCIATED WITH SURFACE TROUGH THAT WILL
EVENTUALLY PUSH EAST AND OUT OF THE REGION. WILL KEEP THE CHANCE
OF SHOWERS GOING IN THE EAST THROUGH THE AFTERNOON. IN THE
WEST...SOME CLEARING IS TRYING TO PUSH INTO NORTHWEST OHIO AND
THIS SHOULD SUPPORT SOME SUNSHINE THROUGH THE AFTERNOON.
ELSEWHERE...CLOUDS SHOULD HOLD IN WITH A FEW BREAKS IN THE
OVERCAST. DUE TO CLOUDS MOST AREAS AND SHOWERS EAST...WILL GO
AHEAD AND BUMP TEMPERATURES DOWN A FEW DEGREES. I STILL THINK THE
EAST WILL RECOVER SINCE WE STILL HAVE A FAIR AMOUNT OF DAYLIGHT
LEFT THIS AFTERNOON AND EVENING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
MID AND UPPER RIDGING STARTING TO BUILD IN TONIGHT SHOULD CAUSE MOST
OF THE SHRA TO END DURING THE EVENING. LIGHT SOUTH WINDS WILL LIKELY
ALLOW FOR MORE PATCHY FOG TO DEVELOP TONIGHT.
THE MODELS CONTINUE TO SHOW THE HIGH TO THE NE HOLDING MOISTURE
AROUND 850 MB OVER THE EAST HALF OF THE CWA ON TUE AND EVEN PRODUCE
SOME LIGHT PRECIP. HAVING A HARD TIME SEEING TOO MUCH CONVECTION
DEVELOP DUE TO THE UPPER RIDGING SO WILL KEEP POPS TO ONLY A SLIGHT
CHANCE OR LESS.
SIMILAR SITUATION ON WED BUT THE MOISTURE AROUND 850 MB NOW SPREAD
OVER MOST OF THE AREA. NAM AGAIN HAS SOME LIGHT PRECIP OVER THE
CENTRAL PART OF THE CWA. GUIDANCE POPS LOW AND ONGOING FORECAST HAS
BEEN DRY SO WILL MAINTAIN THE CONTINUITY AND KEEP POPS AT 14% OR
LESS.
UPPER TROUGH MOVES EAST TO NEAR THE MS RIVER ON THU INDUCING A
SURFACE LOW TO NOSE NE INTO INDIANA BY LATER IN THE DAY. UPPER
RIDGING SHOULD HOLD OFF THE PRECIP IN THE EAST. THE FAR WEST LOOKS
TO HAVE TOO MUCH MOISTURE TO WORK WITH ALONG WITH A LITTLE BETTER
DYNAMICS SO SOME CONVECTION CAN`T BE RULED OUT. THUS WILL ADD A
SLIGHT CHANCE POP IN FOR THAT AREA WHICH WILL ALSO COLLABORATE
BETTER WITH BORDERING FORECASTS.
TEMPS SHOULD WARM TUE INTO WED THEN STAY ABOVE NORMAL FOR THU.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
LONG TERM BEGINS ON FRIDAY WITH THE GFS AND ECMWF FAIRLY CONSISTENT
IN THE PLACEMENT OF WHAT WILL BECOME A CUTOFF UPPER LOW OVER THE
NATIONS MID SECTION. 12Z FRIDAY THE MODELS HAVE THE LOW NEAR KANSAS
CITY WHILE AN UPPER HIGH WILL BE OVER PA AND NY INFLUENCING THE AREA
FROM THE EAST. MEANWHILE WESTERN COUNTIES WILL HAVE INCREASED
MOISTURE FROM THE FLOW AROUND THE LOW. SYSTEMS REMAIN NEARLY
STATIONARY THROUGH SUNDAY THEN BEGIN TO MOVE EAST SUNDAY NIGHT AND
MONDAY. IN GENERAL WILL HAVE CHANCE POPS FOR SHOWERS OR
THUNDERSTORMS WEST WITH MORE CLOUD COVER VS EAST. SATURDAY NIGHT AND
SUNDAY WILL HAVE CHANCE POPS FOR THE ENTIRE AREA AS MOISTURE SHIFTS
EAST. TEMPS MILD WITH NORMAL TO A FEW DEGREES ABOVE NORMAL TEMPS
EXPECTED.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
WEAK SURFACE TROF EXTENDING SOUTH FROM THE ISLANDS THROUGH OHIO.
SHOWERS ARE MAINLY EAST OF THE TROF IN A MIX OF MVFR AND IFR
CONDITIONS ACROSS THE ENTIRE AREA. EXPECTING IFR CONDITIONS TO
AFFECT MUCH OF THE AREA INTO THE MORNING HOURS...LIFTING TO MVFR
THROUGH THE LATE MORNING AND EARLY AFTERNOON AS DRIER AIR
EVENTUALLY BEGINS TO MOVE IN FROM THE WEST. CONCERNED THAT WITH
LIGHT FLOW DRYING ALOFT AND LEFTOVER LOW LEVEL MOISTURE...FOG AND
POSSIBLY A LOW STRATUS WILL REDEVELOP TONIGHT.
.OUTLOOK...NON-VFR POSSIBLE TUESDAY MORNING...THURSDAY MORNING AND
FRIDAY MORNING.
&&
.MARINE...
FOR TODAY LOOKING FOR SOUTH TO SOUTHWEST FLOW BEHIND A WEAK SURFACE
TROF MOVING ACROSS THE REGION. TONIGHT THROUGH FRIDAY...EXPECTING
GENERALLY SOUTH TO SOUTHEAST FLOW FOR MUCH OF THE PERIOD WITH HIGH
PRESSURE TO OUR EAST AND LOW PRESSURE WEST OF THE AREA. NO
HEADLINES ANTICIPATED.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...ADAMS
NEAR TERM...LOMBARDY
SHORT TERM...ADAMS
LONG TERM...TK
AVIATION...TK
MARINE...TK
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
821 PM EDT TUE APR 30 2013
.SYNOPSIS...
A LARGE AREA OF HIGH PRESSURE OFF THE NEW ENGLAND COAST WILL BUILD
OVER THE LOCAL AREA AND PROVIDE DRIER AND BRIGHTER CONDITIONS INTO
THE UPCOMING WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
LARGE AREA OF HIGH PRESSURE OFF THE NEW ENGLAND COAST CONTINUES TO
PUMP LOW LEVEL MOISTURE ONSHORE AND UP INTO CENTRAL PA. CLOUDS
ERODED OVER EASTERN AREAS FOR A TIME BUT LATEST TRENDS SHOW CLOUDS
RETURNING AS NIGHT FALLS AND THE ATMOSPHERE BEGINS TO COOL.
MEANWHILE AN ANOMALOUS /+2-3 SIGMA/ 500 MB RIDGE WILL AMPLIFY
FROM THE TENNESSEE VALLEY TO EASTERN CANADA. DRIER AIR WILL
EVENTUALLY WORK IN..WHICH WILL AID IN RAISING CIGS AND GRADUALLY
DIMINISHING CLOUDS LATER TONIGHT FROM THE EAST. STUBBORN STRATOCU
SHOULD LINGER THE LONGEST /THROUGH 12Z/ IN THE SW WHERE SPOTTY
DRIZZLE WILL REMAIN POSS OVERNIGHT /AS PER THE 4KM NAM AND HRRR -
THOUGH THEY HAVE BEEN OVERDOING POTENTIAL FOR LIGHT PRECIP OVER
THE PAST 24 HRS/.
LOW TEMPS WILL BE IN THE 40S...WITH COOLEST READINGS IN THE
NORTHEAST AND EAST WHERE CLOUDS WILL THIN FIRST AND DEWPOINTS
WILL LOWER FIRST.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
ANOMALOUS /+2-3 SIGMA/ 500 MB RIDGE BEGINS TO QUICKLY AMPLIFY
FROM THE TENNESSEE VALLEY TO EASTERN CANADA ON WED. AFTER A CLOUDY
START IN THE SW...SKIES SHOULD BECOME PARTLY CLOUDY EVERYWHERE BY
LATE MORNING WITH SUNSHINE CONTINUING TO INCREASE IN THE
AFTERNOON AS SUBSIDENCE DEEPENS UNDER THE BUILDING HIGH.
HIGH TEMPS WEDNESDAY WILL WARM BY 8-10F COMPARED TO
TUESDAY...WHICH WILL BE NEAR NORMAL ACROSS THE SUSQ VALLEY...AND
5-8F DEGREES ABOVE NORMAL OVER THE NRN AND WESTERN MTNS. LOWS WED
NIGHT WILL BE CHILLY WITH STRENGTHENING HIGH PRESSURE BRINGING
LIGHT WINDS AND DRIER AIR. READINGS WILL BOTTOM OUT IN THE
40S...WITH SOME UPPER 30S POSS IN NORTHEASTERN MTNS.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
THE 30/12Z GLOBAL NUMERICAL GUIDANCE CONTINUES TO ADVERTISE A HIGHLY
AMPLIFIED MERIDIONAL FLOW PATTERN AT 500MB THROUGH THE MEDIUM RANGE
PERIOD...WITH AN ANOMALOUS RIDGE/TROUGH/RIDGE CONFIGURATION EXPECTED
FROM JUST OFFSHORE THE PAC NW TO THE CENTRAL US AND INTERIOR NORTHEAST
STATES.
A MID-ATLANTIC FORECAST PERSPECTIVE SHOWS A SHARP 580DM RIDGE
CENTERED BETWEEN THE AFOREMENTIONED CENTRAL CONUS H5 TROUGH/CLOSED
LOW AND COMPACT H5 ENERGY PROGGED TO DROP SWD FROM THE MARITIMES
ALONG/JUST OFFSHORE THE NEW ENGLAND COAST ON DAY 3-4 /THUR-FRI/.
THIS FEATURE WILL RETREAT INTO THE NRN ATLC BY THE WEEKEND...WITH
THE FOCUS SHIFTING TO THE EVOLUTION OF THE CLOSED LOW OVER THE
CENTRAL STATES.
THE ECMWF LIES ON THE WWD SIDE OF THE DETERMINISTIC ENVELOPE SHOWING
A MORE COASTAL TRACK WITH THE ENERGY DROPPING OFFSHORE THE NE COAST
EARLY IN THE PERIOD. HOWEVER THE OVERALL MODEL SPREAD IS PRETTY LOW
WITH THIS FEATURE...WHICH SHOULD SEND A BACKDOOR COLD FRONT INTO THE
REGION ON FRIDAY AND ACCENTUATE A WEST-EAST TEMPERATURE GRADIENT.
THE DOMINANT SYNOPTIC FEATURE DRIVING THE SENSIBLE WEATHER IN
CENTRAL PA THROUGH THE BALANCE OF THE PERIOD WILL BE THE HIGH
AMPLITUDE UPPER-LEVEL RIDGE...WHICH SHOULD EFFECTIVELY BLOCK PCPN
ASSOCD WITH THE CENTRAL US CLOSED LOW FROM REACHING THE
NORTHEAST/MID-ATLC STATES AT LEAST THROUGH THE UPCOMING WEEKEND.
THE OPERATIONAL MODELS AND THEIR ENSEMBLE MEANS HAVE MANY VARIED
SOLUTIONS CONCERNING THE EVENTUAL EWD PROGRESSION OF THE CENTRAL US
CLOSED LOW. IN GENERAL...THERE APPEARS TO BE A SLIGHTLY SLOWER AND
SOUTHWARD TREND IN THE MOST RECENT NON-NCEP MODEL DATA. THE SLOWER
TREND MAKES SENSE GIVEN THAT THE MODELS USUALLY TRY TO BREAK DOWN
THESE PATTERNS TOO QUICKLY. THE LATE-SPRING/EARLY MAY TIMEFRAME IS
ALSO A CLIMATALOGICALLY FAVORED PERIOD FOR BLOCKY PATTERNS/CUT-OFF
LOWS. WITH REGARD TO THE EWD MVMT OF THE CLOSED LOW AND CORRESPONDING
CHCS FOR PCPN...WILL UTILIZE AN EVEN BLEND OF AVAILABLE GUIDANCE. THIS
IDEA SEEMS TO FIT THE WPC PREFERENCE OF AN INTERMEDIATE 12Z CANADIAN
OR EC/GEFS MEAN SOLUTION.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
CONDITIONS TOOK NEARLY ALL DAY IMPROVE...BUT MOST LOCATIONS HAVE
RISEN TO OR ABOVE 3KFT CEILINGS. CLOUDS BROKE UP OVER MOST EASTERN
AREAS IN THE LAST 2 HOURS. LOCALLY IN STATE COLLEGE WE SAW LARGE
PATCHES OF BLUE OVER THE PAST HOUR. THE EASTERN HALF OF THE REGION
IS NOW MAINLY VFR AND SHOULD REMAIN SO MOST OF THE TIME FOR THE
NEXT 24 HOURS AND BEYOND.
LINGERING LOW CLOUDS NEAR THE ALLEGHENY FRONT AND LINGERING
DRIZZLE THAT HAS FINALLY ENDED...SHOULD PROVIDE FOR AREAS OF
PATCHY MVFR AND PERHAPS ISOLATED IFR TONIGHT. MAINLY KJST-KAOO UP
INTO KBFD. THIS SHOULD ALL BE GONE SHORTLY AFTER SUNRISE
WEDNESDAY.
ALL THE MODELS SHOW THE EASTERLY FLOW GETTING WEAKER AND STRONGER
RIDGING. THE KEY ITEM FOR THE NEXT 24 HOURS IS DRY AIR WORKING ITS
WAY INTO OUR REGION FROM THE EAST. THIS SHOULD PRODUCE WIDESPREAD
VFR OVER THE REGION WEDNESDAY. WINDS SHOULD BE LIGHT.
THE RIDGE SHOULD TAKE CONTROL OF OUR WEATHER SO WEAK WINDS...LOW
HUMIDITY AND MOSTLY CLEAR SKIES SHOULD DOMINATE INTO THE WEEKEND.
.OUTLOOK...
WED...LOW CIGS POSS EARLY OVR THE W MTNS...OTHERWISE VFR.
THU-SUN...VFR. NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE/RXR
NEAR TERM...LA CORTE/RXR
SHORT TERM...RXR
LONG TERM...STEINBUGL
AVIATION...GRUMM
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
726 PM EDT TUE APR 30 2013
.SYNOPSIS...
A WEAK AREA OF LOW PRESSURE NEAR THE OUTER BANKS OF NORTH
CAROLINA WILL MAINTAIN A SOUTHEASTERLY FLOW OF MOIST AIR INTO
CENTRAL PENNSYLVANIA TONIGHT...KEEPING CLOUDS AROUND WITH A
MENTION OF DRIZZLE FOR THE SOUTHERN MOUNTAINS. A HIGH AMPLITUDE
BLOCKING RIDGE WILL SET UP ACROSS THE REGION FOR THE SECOND HALF
OF THE WEEK...BRINGING DRY AND MILD WEATHER WHICH IS EXPECTED TO
LAST INTO THE UPCOMING WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
THE MAIN BELT OF ANOMALOUS EASTERLIES SHIFTS GRADUALLY SOUTH TO
THE CAROLINAS TONIGHT INTO WEDNESDAY...WHILE AN ANOMALOUS /+2-3
SIGMA/ 500 MB RIDGE AMPLIFIES FROM THE TENNESSEE VALLEY TO EASTERN
CANADA. IN ADDITION...DRIER AIR IS ALREADY BEGINNING TO ADVECT IN
FROM THE EAST...WHICH WILL AID IN RAISING CIGS AND GRADUALLY
DIMINISHING CLOUDS OVERNIGHT FROM THE EAST. STUBBORN STRATOCU
SHOULD LINGER THE LONGEST /THROUGH 12Z/ IN THE SW WHERE SPOTTY
DRIZZLE WILL REMAIN POSS OVERNIGHT /AS PER THE 4KM NAM AND HRRR -
THOUGH THEY HAVE BEEN OVERDOING POTENTIAL FOR LIGHT PRECIP OVER
THE PAST 24 HRS/.
LOW TEMPS WILL BE IN THE 40S...WITH COOLEST READINGS IN THE
NORTHEAST AND EAST WHERE CLOUDS WILL THIN FIRST AND DEWPOINTS
WILL LOWER FIRST.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
ANOMALOUS /+2-3 SIGMA/ 500 MB RIDGE BEGINS TO QUICKLY AMPLIFY
FROM THE TENNESSEE VALLEY TO EASTERN CANADA ON WED. AFTER A CLOUDY
START IN THE SW...SKIES SHOULD BECOME PARTLY CLOUDY EVERYWHERE BY
LATE MORNING WITH SUNSHINE CONTINUING TO INCREASE IN THE
AFTERNOON AS SUBSIDENCE DEEPENS UNDER THE BUILDING HIGH.
HIGH TEMPS WEDNESDAY WILL WARM BY 8-10F COMPARED TO
TUESDAY...WHICH WILL BE NEAR NORMAL ACROSS THE SUSQ VALLEY...AND
5-8F DEGREES ABOVE NORMAL OVER THE NRN AND WESTERN MTNS. LOWS WED
NIGHT WILL BE CHILLY WITH STRENGTHENING HIGH PRESSURE BRINGING
LIGHT WINDS AND DRIER AIR. READINGS WILL BOTTOM OUT IN THE
40S...WITH SOME UPPER 30S POSS IN NORTHEASTERN MTNS.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
THE 30/12Z GLOBAL NUMERICAL GUIDANCE CONTINUES TO ADVERTISE A HIGHLY
AMPLIFIED MERIDIONAL FLOW PATTERN AT 500MB THROUGH THE MEDIUM RANGE
PERIOD...WITH AN ANOMALOUS RIDGE/TROUGH/RIDGE CONFIGURATION EXPECTED
FROM JUST OFFSHORE THE PAC NW TO THE CENTRAL US AND INTERIOR NORTHEAST
STATES.
A MID-ATLANTIC FORECAST PERSPECTIVE SHOWS A SHARP 580DM RIDGE
CENTERED BETWEEN THE AFOREMENTIONED CENTRAL CONUS H5 TROUGH/CLOSED
LOW AND COMPACT H5 ENERGY PROGGED TO DROP SWD FROM THE MARITIMES
ALONG/JUST OFFSHORE THE NEW ENGLAND COAST ON DAY 3-4 /THUR-FRI/.
THIS FEATURE WILL RETREAT INTO THE NRN ATLC BY THE WEEKEND...WITH
THE FOCUS SHIFTING TO THE EVOLUTION OF THE CLOSED LOW OVER THE
CENTRAL STATES.
THE ECMWF LIES ON THE WWD SIDE OF THE DETERMINISTIC ENVELOPE SHOWING
A MORE COASTAL TRACK WITH THE ENERGY DROPPING OFFSHORE THE NE COAST
EARLY IN THE PERIOD. HOWEVER THE OVERALL MODEL SPREAD IS PRETTY LOW
WITH THIS FEATURE...WHICH SHOULD SEND A BACKDOOR COLD FRONT INTO THE
REGION ON FRIDAY AND ACCENTUATE A WEST-EAST TEMPERATURE GRADIENT.
THE DOMINANT SYNOPTIC FEATURE DRIVING THE SENSIBLE WEATHER IN
CENTRAL PA THROUGH THE BALANCE OF THE PERIOD WILL BE THE HIGH
AMPLITUDE UPPER-LEVEL RIDGE...WHICH SHOULD EFFECTIVELY BLOCK PCPN
ASSOCD WITH THE CENTRAL US CLOSED LOW FROM REACHING THE
NORTHEAST/MID-ATLC STATES AT LEAST THROUGH THE UPCOMING WEEKEND.
THE OPERATIONAL MODELS AND THEIR ENSEMBLE MEANS HAVE MANY VARIED
SOLUTIONS CONCERNING THE EVENTUAL EWD PROGRESSION OF THE CENTRAL US
CLOSED LOW. IN GENERAL...THERE APPEARS TO BE A SLIGHTLY SLOWER AND
SOUTHWARD TREND IN THE MOST RECENT NON-NCEP MODEL DATA. THE SLOWER
TREND MAKES SENSE GIVEN THAT THE MODELS USUALLY TRY TO BREAK DOWN
THESE PATTERNS TOO QUICKLY. THE LATE-SPRING/EARLY MAY TIMEFRAME IS
ALSO A CLIMATALOGICALLY FAVORED PERIOD FOR BLOCKY PATTERNS/CUT-OFF
LOWS. WITH REGARD TO THE EWD MVMT OF THE CLOSED LOW AND CORRESPONDING
CHCS FOR PCPN...WILL UTILIZE AN EVEN BLEND OF AVAILABLE GUIDANCE. THIS
IDEA SEEMS TO FIT THE WPC PREFERENCE OF AN INTERMEDIATE 12Z CANADIAN
OR EC/GEFS MEAN SOLUTION.
&&
.AVIATION /23Z TUESDAY THROUGH SUNDAY/...
CONDITIONS TOOK NEARLY ALL DAY IMPROVE...BUT MOST LOCATIONS HAVE
RISEN TO OR ABOVE 3KFT CEILINGS. CLOUDS BROKE UP OVER MOST EASTERN
AREAS IN THE LAST 2 HOURS. LOCALLY IN STATE COLLEGE WE SAW LARGE
PATCHES OF BLUE OVER THE PAST HOUR. THE EASTERN HALF OF THE REGION
IS NOW MAINLY VFR AND SHOULD REMAIN SO MOST OF THE TIME FOR THE
NEXT 24 HOURS AND BEYOND.
LINGERING LOW CLOUDS NEAR THE ALLEGHENY FRONT AND LINGERING
DRIZZLE THAT HAS FINALLY ENDED...SHOULD PROVIDE FOR AREAS OF
PATCHY MVFR AND PERHAPS ISOLATED IFR TONIGHT. MAINLY KJST-KAOO UP
INTO KBFD. THIS SHOULD ALL BE GONE SHORTLY AFTER SUNRISE
WEDNESDAY.
ALL THE MODELS SHOW THE EASTERLY FLOW GETTING WEAKER AND STRONGER
RIDGING. THE KEY ITEM FOR THE NEXT 24 HOURS IS DRY AIR WORKING ITS
WAY INTO OUR REGION FROM THE EAST. THIS SHOULD PRODUCE WIDESPREAD
VFR OVER THE REGION WEDNESDAY. WINDS SHOULD BE LIGHT.
THE RIDGE SHOULD TAKE CONTROL OF OUR WEATHER SO WEAK WINDS...LOW
HUMIDITY AND MOSTLY CLEAR SKIES SHOULD DOMINATE INTO THE WEEKEND.
.OUTLOOK...
WED NIGHT...MAINLY VFR.
THU-SUN...VFR. NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RXR
NEAR TERM...RXR
SHORT TERM...RXR
LONG TERM...STEINBUGL
AVIATION...GRUMM
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
531 PM EDT MON APR 29 2013
.SYNOPSIS...
A RIDGE OF HIGH PRESSURE WILL STRENGTHEN ATOP THE REGION THROUGH
MIDWEEK AND LINGER INTO THE UPCOMING WEEKEND.
&&
.NEAR TERM /THROUGH TUESDAY/...
AS OF 530 PM...LATEST RUC AND WATER VAPOR IMAGERY SHOW THE AXIS OF A
SHORT WAVE ALREADY EAST OF THE NC FOOTHILLS. NVA BEHIND THIS FEATURE
WAS APPARENTLY DOING ITS BEST TO SQUASH ANY OF THE ENHANCED CU FROM
GROWING TO ANY GREAT EXTENT. THE KGSP WAS RELATIVELY QUIET AND
EXPECT IT TO STAY THAT WAY. HAVE KNOCKED THE POP DOWN TO KEEP IT IN
THE SLIGHT CHANCE RANGE THROUGH THE EARLY PART OF THE EVENING.
PREVIOUS DISCUSSION...
AS OF 230 PM EDT MONDAY...A SHORT WAVE TROUGH WILL PUSH EAST OF THE
REGION THIS EVENING. NVA AND DEEP LAYER RIDGING WILL FOLLOW IN IT/S
WAKE. THERE COULD STILL BE SOME SHOWER OR THUNDERSTORM ACTIVITY LATE
THIS AFTERNOON AND EVENING...PARTICULARLY ALONG THE BLUE RIDGE AND
OUT ACROSS THE NC FOOTHILLS. SO I/VE HELD ON TO SOME LOW END CHANCE
POPS ACROSS THESE ZONES. LATER TONIGHT THE STAGE LOOKS SET FOR
WIDESPREAD DENSE FOG. THE NAM CONDENSATION PRESSURE DEFICITS FALL TO
ZERO ACROSS ALL OF THE FA EXCEPT THE MTN RIDGE-TOPS. THERE WILL BE
DEEP LAYER DRYING AND WINDS WILL BE LIGHT. WE HAD WIDESPREAD RAIN
OVER THE PAST COUPLE DAYS AND THE GROUND IS QUITE MOIST. I DEBATED
ISSUING A DENSE FOG ADVISORY...BUT THERE IS JUST ENOUGH LLVL FLOW
THAT A LOW STRATUS DECK COULD DEVELOP INSTEAD. ALSO...THE
NEIGHBORING OFFICES I SPOKE WITH WERE INCLINED TO WAIT ON ISSUING AN
ADVISORY AND THAT/S WHAT I WILL DO AS WELL. STILL...I DO HAVE
WIDESPREAD DENSE FOG IN THE GRIDS AND I/LL HIT IT IN THE HWO.
THAT DEEP LAYER RIDGE REMAINS OVERHEAD ON TUESDAY. WINDS WILL BE
LIGHT AND THE NAM SOUNDINGS ARE SHOWING A PRONOUNCED INVERSION. A
FEW SHRA ARE POSSIBLE ACROSS THE NC MTNS...BUT I/VE PULLED POPS OVER
THE FOOTHILLS AND PIEDMONT. IT WILL BE A MILD DAY WITH NEAR SEASONAL
TEMPERATURES.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
AS OF 145 PM MONDAY...AVERAGE MODEL AGREEMENT IN THE SHORT
TERM...GIVEN SUBTLE UPPER FEATURES AND OVERALL WEAK FORCING ACRS THE
CWFA. AN UPPER RIDGE WILL BUILD OVER THE EASTERN GREAT LAKES THRU
THE PERIOD...WHILE A WEAK AREA OF LOW PRES WILL LINGER INVOF THE
EASTERN GULF/FL. THIS PATTERN WILL SET UP A DEEP ELY FLOW...WITH AN
INVERTED TROF OFF THE CAROLINA COASTS AND HIGH PRES ANCHORED OVR NEW
ENGLAND WITH A WEDGE SW DOWN THE ENTIRE APPALACHIAN CHAIN. THERE ARE
SUBTLE DIFFERENCES AMONG THE OP MODELS ON A COUPLE OF WEAK WAVES
IN THE LLVL ELY FLOW. OVERALL...THE GFS IS MORE STABLE WITH AN
ATLANTIC MARINE LAYER AND STRONGER WEDGE THAN THE NAM. A LOOK AT THE
STRENGTH OF THE FLOW (850 MB WINDS GENERALLY UNDER 25 KTS) AND LACK
OF UPPER Q-VECTOR CONVERGENCE...I THINK TUESDAY NIGHT AND WEDNESDAY
WILL BE GENERALLY DRY. THE SW NC MTNS LOOK TO HAVE THE MOST INSTBY
AND WITH MTN-TOP CONVERGENCE...MAY HAVE A FEW SHWRS/TSTMS WED AFTN.
OTHERWISE...EXPECTING AN INCREASE IN STRATOCUMULUS BY DAYBREAK
WEDNESDAY...BREAKING UP SOMEWHAT DURING THE DAY. TEMPS WILL BE NEAR
NORMAL FOR LOWS...AND ABOUT A CATEGORY BELOW NORMAL FOR HIGHS.
THERE SEEMS TO BE A CONSENSUS ON A SURGE IN 850-700 MB ATLANTIC
MOISTURE ADVECTING IN...AS FLOW VEERS FROM ENE TO ESE WEDNESDAY
NIGHT INTO THURSDAY (PASSAGE OF AN ELY WAVE). MEANWHILE...A
SUBSIDENCE INVERSION STRENGTHENS IN BOTH THE NAM AND GFS SNDGS ATOP
THE MOIST LAYER. THIS INVERSION SETS UP AROUND 700-600 MB LAYER BY
THURSDAY AFTN. THE NAM AND GFS 295 K SFC BOTH SHOW SOME MOIST
UPGLIDE. PERSISTING FROM ABOUT 06Z THURSDAY TILL 00Z FRIDAY . THAT
ALONG WILL ELY UPSLOPE FLOW ALONG THE BLUE RIDGE SEEMS TO WARRANT
KEEPING A SHOTGUN LOW-END CHC POP EARLY THURSDAY MORNING...THEN
TAPERING OFF IN THE NE HALF OF THE CWFA THURSDAY AFTN...AS DRY AIR
WORKS BACK IN. MIN TEMPS SIMILAR TO TUESDAY NIGHT...BUT EXPECTING
COOLER TEMPS ON THURSDAY AS THICKNESSES FALL UNDER THE WEDGE
(GENERALLY UPR 60S TO LWR 70S).
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 200 PM MONDAY...THE LATEST AVAILABLE MEDIUM RANGE GUIDANCE IS
STILL PROGGING THE CWFA TO BE WITHIN A MOISTURE AND FORCING MINIMA
ON FRIDAY AND IT IS DEBATABLE IF THE LLVL EASTERLY FLOW WILL BE ENUF
TO FORCE ANYTHING MORE THAN A FEW SHOWERS WHICH I DOUBT. MAX TEMPS
ARE SLATED TO BE COOL FOR EARLY MAY...SVRL CATEGORIES BELOW CLIMO.
OMEGA BLOCKING PATTERN CONTINUES INTO THE WEEKEND...AND WITH THE
29/12 UTC OP GFS RUN TO RUN INCONSISTENCY IN HANDLING PLAINS UPPER
LOW MOVEMENT...PREFER TO LEAN TO 29/00 UTC OP ECMWF WITH RESPECT TO
UPPER RIDGE POSITION. BASED ON THIS...WILL PLAN ON ROUGHLY A COOL
PERSISTENCE FCST FOR SATURDAY AND SUNDAY WITH JUST A TOKEN SHOWER
CHANCE EACH DAY WITH TEMPS BY MONDAY GETTING CLOSER TO CLIMO.
&&
.AVIATION /22Z MONDAY THROUGH SATURDAY/...
AT KCLT AND ELSEWHERE...CIGS WILL SLOWLY LIFT INTO THE VFR RANGE BY
LATE AFTN. WINDS WILL GENERALLY BE OUT OF THE SOUTHWEST AT SPEEDS
LESS THAN 10 KTS. IT DOESN/T APPEAR THAT MUCH SHOWER ACTIVITY WILL
DEVELOP...AND THE TEMPO GROUPS FOR SHRA HAVE BEEN REMOVED. THE BIG
NEWS IS THE FOG POTENTIAL FOR TONIGHT. SEVERAL FACTORS SUGGEST DENSE
FOG LATER TONIGHT OVER MOST OF THE REGION. IT WILL BE DRY ALOFT. THE
LLVL WINDS WILL BE LIGHT...WHICH SHOULD KEEP ORGANIZED STRATUS FROM
DEVELOPING. RECENT WIDESPREAD RAIN HAS RESULTED IN VERY MOIST SOIL
CONDITIONS. THEREFORE I/VE ADDED FOG TO ALL THE TAFS FOR TONIGHT.
I/VE CAPPED THE LOWER END OF THE VSBY AT 1/2SM AT MANY
SITES...THOUGH I SUSPECT MOST AIRFIELDS WILL SEE 1/4SM FOR SEVERAL
HOURS LATE TONIGHT.
OUTLOOK...MORNING LOW CLOUDS AND FOG...WITH A SMALL CHANCE OF
AFTERNOON SHOWERS/THUNDERSTORMS EACH DAY THROUGH AT LEAST MID WEEK.
CONFIDENCE TABLE...
21-03Z 03-09Z 09-15Z 15-21Z
KCLT MED 64% LOW 59% MED 67% HIGH 94%
KGSP HIGH 100% MED 67% LOW 40% HIGH 86%
KAVL HIGH 97% MED 79% MED 62% MED 68%
KHKY HIGH 98% MED 75% LOW 54% HIGH 98%
KGMU HIGH 100% MED 72% LOW 57% HIGH 84%
KAND HIGH 92% MED 78% MED 66% HIGH 84%
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...CSH
NEAR TERM...MCAVOY/PM
SHORT TERM...ARK
LONG TERM...CSH
AVIATION...MCAVOY
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
420 PM CDT MON APR 29 2013
UPDATED TO ADD SMALL CRAFT ADVISORY MARINE ZONE CODING.
.VERY SHORT TERM...TONIGHT AND TUESDAY. FORECAST CONFIDENCE IS
MEDIUM.
LINE OF ELEVATED SHOWERS AND A FEW THUNDERSTORMS SHIFTING EAST
NORTHEAST THROUGH THE AREA AT THIS TIME...BEING FED BY SOUTH
SOUTHWESTERLY 850MB LOW LEVEL JET NOSE. THESE SHOULD CONTINUE TO
MOVE THROUGH THE REMAINDER OF THE AREA LATE THIS AFTERNOON.
SOUTHWESTERLY 850MB LOW LEVEL JET NOSE WILL CONTINUE TO POINT INTO
THE AREA TONIGHT...GRADUALLY INCREASING IN MAGNITUDE. WARM AIR
ADVECTION KICKS IN TONIGHT AS WELL. TAIL END OF 500MB VORTICITY
MAXIMUM OVER SOUTHERN MINNESOTA WILL SHIFT CLIP THE NORTHERN
PORTIONS OF THE AREA THROUGH EARLY EVENING...WITH ANOTHER OVER
EASTERN NEBRASKA SHIFTING INTO THE AREA BY 06Z TUESDAY.
ADJUSTING AREA FORECAST SOUNDINGS FOR LOWER TO MID 50S DEW POINTS
YIELD MEAN LAYER CAPES OF UP TO 500 J/KG INTO EARLY EVENING...THEN
SHOW ELEVATED CAPES INCREASING TONIGHT OVER 1000 J/KG. THIS IS IN
RESPONSE TO MOISTURE BUILDING IN THE 925MB TO 850MB LEVEL. DEEP
LAYER SHEAR IS STRONG INTO EARLY EVENING...THEN WEAKENS SOMEWHAT
LATER TONIGHT AS MID LEVEL WINDS WEAKEN. SPC HAS SLIGHT RISK AREA
INTO JUST THE FAR SOUTHWESTERN SECTIONS OF THE AREA. MAIN RISK
APPEARS TO BE IN IOWA...THOUGH IF HIGHER DEW POINTS MOVE IN AND
INCREASE CAPE THIS EVENING...COULD SEE A SEVERE STORM OR TWO OCCUR.
4KM WRF/NMM MODEL SHOWING SPOTTY SHOWERS AND A FEW STORMS THIS
EVENING...WITH A MORE ORGANIZED AREA OF SHOWERS AND STORMS FOR LATER
TONIGHT WITH LOW LEVEL JET FORCING. HRRR KEEPING BULK OF CONVECTION
JUST SOUTH AND SOUTHWEST OF THE AREA TONIGHT. FOR NOW...WILL GO WITH
SCATTERED SHOWERS AND ISOLATED STORMS EARLY THIS EVENING...WITH
THUNDER FOR LATER THIS EVENING AND OVERNIGHT.
MODELS SHOWING WARM SECTOR AIRMASS MOVING INTO THE AREA
TUESDAY...CAPPING OFF THE AREA FROM PRECIPITATION. GUSTY
SOUTH/SOUTHWEST WINDS AND EXPECTED 925MB TEMPERATURES SHOULD BRING
HIGHS INTO THE LOWER 80S IN MOST AREAS. COOLER VALUES NEAR SHEBOYGAN
WITH SOUTH ONSHORE WINDS. APPROACHING COLD FRONT LATER IN THE
AFTERNOON SHOULD BRING INCREASED CHANCES FOR THUNDERSTORMS...THOUGH
BEST SHOT IS INTO TUESDAY NIGHT.
.SHORT TERM...TUESDAY NIGHT THROUGH THURSDAY.
TUESDAY NIGHT AND WEDNESDAY...FORECAST CONFIDENCE LOW TO MEDIUM.
THUNDERSTORMS ALONG AND AHEAD OF THE FRONTAL BOUNDARY ONGOING AT THE
BEGINNING OF THE PERIOD EXPECTED TO TRANSITION TO MAINLY RAIN
SHOWERS FROM NORTHWEST TO SOUTHEAST BEHIND THE FRONT ON WEDNESDAY AS
IT SAGS THROUGH THE FORECAST AREA. THOUGH SURFACE FRONT MAKES IT TO
OR NEAR SE WI BY 12Z WED...UPPER TROUGH STILL WELL TO THE WEST AND
WILL KEEP THE FOCUS FOR PRECIPITATION THROUGH IOWA INTO WESTERN WI.
WILL KEEP CHANCE POPS ALONG THE FRONT.
LOWS WILL NOT FALL OFF MUCH TUESDAY NIGHT UNTIL LATE IN THE
NW...THEN WARM SE WEDNESDAY AHEAD OF STALLED BAROCLINIC ZONE
BISECTING THE CWA...THOUGH COOLER ALONG THE LAKE.
WEDNESDAY NIGHT AND THURSDAY...FORECAST CONFIDENCE MEDIUM.
LIKELY POPS INTO THE WESTERN CWA WITH INCREASING FORCING AHEAD OF
SLOWLY APPROACHING TROUGH AS IT DEEPENS OVER THE CENTRAL U.S.
MODELS STILL DIFFER WITH THE PLACEMENT OF BAROCLINIC ZONE WHICH
AFFECTS NOT ONLY TEMPERATURES BUT LOCATION OF BETTER LOW TO MID
LEVEL FRONTOGENESIS AND Q-VECTOR CONVERGENCE.
BLENDED SOLUTION KEEPS LIKELY POPS OVER SOUTH CENTRAL WI THROUGH THE
DAY THURSDAY...THEN SHIFT ACROSS THE ENTIRE CWA THURSDAY NIGHT.
THERMAL RIDGE NOSING INTO THE FAR SOUTH WILL BRING HIGHS IN THE
UPPER 50S THERE...THEN TAPER OFF TO THE MID 40S NW WITH UPPER 40S
ALONG THE LAKE.
.LONG TERM...THURSDAY NIGHT THROUGH MONDAY. FORECAST CONFIDENCE...
LOW.
MODELS STILL TRYING TO GET A HANDLE ON LOW CUTTING-OFF OVER THE
CENTRAL PLAINS THURSDAY NIGHT AND THEN LIFTING SLOWLY NWD INTO THE
UPPER MIDWEST SUNDAY. SOME THERMAL DIFFERENCES THAT MAY IMPACT
PRECIPITATION TYPE AND BRING SOME SNOWFLAKES MIXING IN WITH THE RAIN
IN THE FAR WEST/NW LATE THURSDAY NIGHT...BUT WILL LEAVE ALL LIQUID
FOR NOW. OTHERWISE A CLOUDY...COOL AND WET PERIOD THROUGH THE
WEEKEND WITH TEMPERATURES STRUGGLING INTO THE LOWER 50S...COOLER BY
THE LAKE WITH GENERALLY EASTERLY FLOW. PERIODS OF RAIN...WITH
INTENSITY DEPENDENT ON STRENGTH OF VORTICITY MAXIMA ROTATING THROUGH
THE REGION AND THE AMOUNT OF AVAILABLE MOISTURE WITH STREAMERS OF
DRIER AIR WRAPPING AROUND CIRCULATION. SOME HOPE THAT THE LOW WILL
LIFT FAR ENOUGH AWAY BY MONDAY TO LOWER RAIN CHANCES AND ALLOW
WARMER TEMPS.
AVIATION/00Z TAFS/...
VFR CONDITIONS ARE EXPECTED THIS EVENING ACROSS TAF SITES. SCATTERED
SHOWERS AND A FEW THUNDERSTORMS MOVING THROUGH AT THIS TIME...WITH
MORE AT TIMES MAINLY LATER TONIGHT INTO EARLY TUESDAY MORNING. THERE
WILL BE LULLS IN THE PRECIPITATION.
FOR NOW...WILL KEEP VICINITY THUNDER WORDING IN TAFS...AS THERE IS
SOME UNCERTAINTY WITH THE EXACT TIMING AND AREAL COVERAGE OF THE
SHOWERS AND STORMS. ANY STORMS WOULD BRING VISIBILITIES DOWN TO
NEAR ALTERNATE MINIMUMS...WITH MVFR CEILINGS.
SOUTH WINDS TONIGHT WILL GRADUALLY INCREASE AND SHIFT SOUTHWEST BY
TUESDAY AFTERNOON. GUSTS TO 25 KNOTS OR SO ARE EXPECTED BY TUESDAY
AFTERNOON.
MARINE...
A TIGHT PRESSURE GRADIENT WILL DEVELOP OVER THE NEARSHORE WATERS
TUESDAY...WHICH WILL RESULT IN GUSTY SOUTH WINDS. FREQUENT GUSTS TO
25 KNOTS ARE EXPECTED. THUS...A SMALL CRAFT ADVISORY WILL BE ISSUED
FROM MID MORNING THROUGH EARLY EVENING TUESDAY.
ANOTHER TIGHT PRESSURE GRADIENT WILL DEVELOP WITH THE INFLUX OF
COLDER AIR FOR WEDNESDAY NIGHT THROUGH THURSDAY NIGHT. THIS WILL
BRING BRISK AND GUSTY NORTH TO NORTHEAST WINDS DURING THIS
TIME...ALONG WITH HIGH WAVES. A SMALL CRAFT ADVISORY MAY BE NEEDED
DURING THIS TIME.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY FROM 10 AM TO 7 PM CDT TUESDAY FOR
LMZ643>646.
&&
$$
TONIGHT/TUESDAY AND AVIATION/MARINE...WOOD
TUESDAY NIGHT THROUGH MONDAY...REM
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
349 PM CDT MON APR 29 2013
.VERY SHORT TERM...TONIGHT AND TUESDAY. FORECAST CONFIDENCE IS MEDIUM.
LINE OF ELEVATED SHOWERS AND A FEW THUNDERSTORMS SHIFTING EAST
NORTHEAST THROUGH THE AREA AT THIS TIME...BEING FED BY SOUTH
SOUTHWESTERLY 850MB LOW LEVEL JET NOSE. THESE SHOULD CONTINUE TO
MOVE THROUGH THE REMAINDER OF THE AREA LATE THIS AFTERNOON.
SOUTHWESTERLY 850MB LOW LEVEL JET NOSE WILL CONTINUE TO POINT INTO
THE AREA TONIGHT...GRADUALLY INCREASING IN MAGNITUDE. WARM AIR
ADVECTION KICKS IN TONIGHT AS WELL. TAIL END OF 500MB VORTICITY
MAXIMUM OVER SOUTHERN MINNESOTA WILL SHIFT CLIP THE NORTHERN
PORTIONS OF THE AREA THROUGH EARLY EVENING...WITH ANOTHER OVER
EASTERN NEBRASKA SHIFTING INTO THE AREA BY 06Z TUESDAY.
ADJUSTING AREA FORECAST SOUNDINGS FOR LOWER TO MID 50S DEW POINTS
YIELD MEAN LAYER CAPES OF UP TO 500 J/KG INTO EARLY EVENING...THEN
SHOW ELEVATED CAPES INCREASING TONIGHT OVER 1000 J/KG. THIS IS IN
RESPONSE TO MOISTURE BUILDING IN THE 925MB TO 850MB LEVEL. DEEP
LAYER SHEAR IS STRONG INTO EARLY EVENING...THEN WEAKENS SOMEWHAT
LATER TONIGHT AS MID LEVEL WINDS WEAKEN. SPC HAS SLIGHT RISK AREA
INTO JUST THE FAR SOUTHWESTERN SECTIONS OF THE AREA. MAIN RISK
APPEARS TO BE IN IOWA...THOUGH IF HIGHER DEW POINTS MOVE IN AND
INCREASE CAPE THIS EVENING...COULD SEE A SEVERE STORM OR TWO OCCUR.
4KM WRF/NMM MODEL SHOWING SPOTTY SHOWERS AND A FEW STORMS THIS
EVENING...WITH A MORE ORGANIZED AREA OF SHOWERS AND STORMS FOR LATER
TONIGHT WITH LOW LEVEL JET FORCING. HRRR KEEPING BULK OF CONVECTION
JUST SOUTH AND SOUTHWEST OF THE AREA TONIGHT. FOR NOW...WILL GO WITH
SCATTERED SHOWERS AND ISOLATED STORMS EARLY THIS EVENING...WITH
THUNDER FOR LATER THIS EVENING AND OVERNIGHT.
MODELS SHOWING WARM SECTOR AIRMASS MOVING INTO THE AREA
TUESDAY...CAPPING OFF THE AREA FROM PRECIPITATION. GUSTY
SOUTH/SOUTHWEST WINDS AND EXPECTED 925MB TEMPERATURES SHOULD BRING
HIGHS INTO THE LOWER 80S IN MOST AREAS. COOLER VALUES NEAR SHEBOYGAN
WITH SOUTH ONSHORE WINDS. APPROACHING COLD FRONT LATER IN THE
AFTERNOON SHOULD BRING INCREASED CHANCES FOR THUNDERSTORMS...THOUGH
BEST SHOT IS INTO TUESDAY NIGHT.
.SHORT TERM...TUESDAY NIGHT THROUGH THURSDAY.
TUESDAY NIGHT AND WEDNESDAY...FORECAST CONFIDENCE LOW TO MEDIUM.
THUNDERSTORMS ALONG AND AHEAD OF THE FRONTAL BOUNDARY ONGOING AT THE
BEGINNING OF THE PERIOD EXPECTED TO TRANSITION TO MAINLY RAIN
SHOWERS FROM NORTHWEST TO SOUTHEAST BEHIND THE FRONT ON WEDNESDAY AS
IT SAGS THROUGH THE FORECAST AREA. THOUGH SURFACE FRONT MAKES IT TO
OR NEAR SE WI BY 12Z WED...UPPER TROUGH STILL WELL TO THE WEST AND
WILL KEEP THE FOCUS FOR PRECIPITATION THROUGH IOWA INTO WESTERN WI.
WILL KEEP CHANCE POPS ALONG THE FRONT.
LOWS WILL NOT FALL OFF MUCH TUESDAY NIGHT UNTIL LATE IN THE
NW...THEN WARM SE WEDNESDAY AHEAD OF STALLED BAROCLINIC ZONE
BISECTING THE CWA...THOUGH COOLER ALONG THE LAKE.
WEDNESDAY NIGHT AND THURSDAY...FORECAST CONFIDENCE MEDIUM.
LIKELY POPS INTO THE WESTERN CWA WITH INCREASING FORCING AHEAD OF
SLOWLY APPROACHING TROUGH AS IT DEEPENS OVER THE CENTRAL U.S.
MODELS STILL DIFFER WITH THE PLACEMENT OF BAROCLINIC ZONE WHICH
AFFECTS NOT ONLY TEMPERATURES BUT LOCATION OF BETTER LOW TO MID
LEVEL FRONTOGENESIS AND Q-VECTOR CONVERGENCE.
BLENDED SOLUTION KEEPS LIKELY POPS OVER SOUTH CENTRAL WI THROUGH THE
DAY THURSDAY...THEN SHIFT ACROSS THE ENTIRE CWA THURSDAY NIGHT.
THERMAL RIDGE NOSING INTO THE FAR SOUTH WILL BRING HIGHS IN THE
UPPER 50S THERE...THEN TAPER OFF TO THE MID 40S NW WITH UPPER 40S
ALONG THE LAKE.
.LONG TERM...THURSDAY NIGHT THROUGH MONDAY. FORECAST CONFIDENCE...
LOW.
MODELS STILL TRYING TO GET A HANDLE ON LOW CUTTING-OFF OVER THE
CENTRAL PLAINS THURSDAY NIGHT AND THEN LIFTING SLOWLY NWD INTO THE
UPPER MIDWEST SUNDAY. SOME THERMAL DIFFERENCES THAT MAY IMPACT
PRECIPITATION TYPE AND BRING SOME SNOWFLAKES MIXING IN WITH THE RAIN
IN THE FAR WEST/NW LATE THURSDAY NIGHT...BUT WILL LEAVE ALL LIQUID
FOR NOW. OTHERWISE A CLOUDY...COOL AND WET PERIOD THROUGH THE
WEEKEND WITH TEMPERATURES STRUGGLING INTO THE LOWER 50S...COOLER BY
THE LAKE WITH GENERALLY EASTERLY FLOW. PERIODS OF RAIN...WITH
INTENSITY DEPENDENT ON STRENGTH OF VORTICITY MAXIMA ROTATING THROUGH
THE REGION AND THE AMOUNT OF AVAILABLE MOISTURE WITH STREAMERS OF
DRIER AIR WRAPPING AROUND CIRCULATION. SOME HOPE THAT THE LOW WILL
LIFT FAR ENOUGH AWAY BY MONDAY TO LOWER RAIN CHANCES AND ALLOW
WARMER TEMPS.
&&
.AVIATION/00Z TAFS/...
VFR CONDITIONS ARE EXPECTED THIS EVENING ACROSS TAF SITES. SCATTERED
SHOWERS AND A FEW THUNDERSTORMS MOVING THROUGH AT THIS TIME...WITH
MORE AT TIMES MAINLY LATER TONIGHT INTO EARLY TUESDAY MORNING. THERE
WILL BE LULLS IN THE PRECIPITATION.
FOR NOW...WILL KEEP VICINITY THUNDER WORDING IN TAFS...AS THERE IS
SOME UNCERTAINTY WITH THE EXACT TIMING AND AREAL COVERAGE OF THE
SHOWERS AND STORMS. ANY STORMS WOULD BRING VISIBILITIES DOWN TO
NEAR ALTERNATE MINIMUMS...WITH MVFR CEILINGS.
SOUTH WINDS TONIGHT WILL GRADUALLY INCREASE AND SHIFT SOUTHWEST BY
TUESDAY AFTERNOON. GUSTS TO 25 KNOTS OR SO ARE EXPECTED BY TUESDAY
AFTERNOON.
&&
.MARINE...
A TIGHT PRESSURE GRADIENT WILL DEVELOP OVER THE NEARSHORE WATERS
TUESDAY...WHICH WILL RESULT IN GUSTY SOUTH WINDS. FREQUENT GUSTS TO
25 KNOTS ARE EXPECTED. THUS...A SMALL CRAFT ADVISORY WILL BE ISSUED
FROM MID MORNING THROUGH EARLY EVENING TUESDAY.
ANOTHER TIGHT PRESSURE GRADIENT WILL DEVELOP WITH THE INFLUX OF
COLDER AIR FOR WEDNESDAY NIGHT THROUGH THURSDAY NIGHT. THIS WILL
BRING BRISK AND GUSTY NORTH TO NORTHEAST WINDS DURING THIS
TIME...ALONG WITH HIGH WAVES. A SMALL CRAFT ADVISORY MAY BE NEEDED
DURING THIS TIME.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TONIGHT/TUESDAY AND AVIATION/MARINE...WOOD
TUESDAY NIGHT THROUGH MONDAY...REM
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1240 PM CDT MON APR 29 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 354 AM CDT MON APR 29 2013
A VERY ACTIVE WEATHER PATTERN IN STORE FOR THE REGION THIS WEEK.
FIRST OFF...WILL BE WATCHING A WEAK COLD FRONT SAGGING SOUTH ACROSS
THE AREA TODAY. TWO SHORTWAVE TROUGHS ARE EXPECTED TO MOVE ACROSS
THE UPPER MISSISSIPPI RIVER VALLEY TODAY AND INTERACT WITH THE FRONT
AS IT EDGES SOUTH...SPARKING OFF SHOWERS AND THUNDERSTORMS. THE
FIRST LEADING SHORTWAVE WAS RACING EAST ACROSS SOUTH DAKOTA EARLY
THIS MORNING WHILE THE SECOND WAVE WAS MOVING EAST ACROSS WYOMING.
THE LEADING TROUGH WILL MOVE ACROSS THE REGION THIS MORNING
KEEPING SHOWERS AND ISOLATED THUNDERSTORMS GOING THROUGH MUCH OF
THE MORNING HOURS. THE TRAILING WAVE WILL ARRIVE EARLY THIS
AFTERNOON...PUSHING ACROSS NORTHERN IOWA THEN INTO SOUTHERN
WISCONSIN BY LATE AFTERNOON INTO THE EARLY EVENING HOURS. THE
FRONT IS EXPECTED TO STALL OUT ACROSS NORTHERN IOWA THROUGH
SOUTHERN WISCONSIN LATE THIS AFTERNOON AND THEN START TO LIFT
NORTH AND ACT AS A WARM FRONT LATE THIS AFTERNOON INTO THIS
EVENING AS VIGOROUS TROUGH DIVES INTO THE NORTHWEST CONUS. AN
INTERESTING ENVIRONMENT SETS UP OVER NORTHEAST IOWA AND FAR
SOUTHWEST WISCONSIN LATE THIS AFTERNOON AS THIS WARM FRONT TAKES
SHAPE. KBLR NAM FORECAST SOUNDINGS SHOW RATHER IMPRESSIVE SHEAR
PROFILES...WITH 0-6 KM BULK SHEAR OF 45 TO 50 KTS...AND 0-1 KM
BULK SHEAR OF 20 TO 25 KTS. CURVATURE ALSO NOTED IN THE HODOGRAPH
FROM THE SURFACE TO 2 KM. THE RAP IS ALSO SHOWING SIMILAR SHEAR
PROFILES. THE NAM IS INDICATING NEARLY 1500 J/KG 0-3KM MUCAPE
VALUES ACROSS THESE AREAS THIS AFTERNOON...BUT THIS IS LIKELY WAY
OVERDONE GIVEN THE NAM IS SHOWING DEWPOINTS CLIMBING TO 60 DEGREES
THIS AFTERNOON. 60 DEGREE DEWPOINTS ARE DISPLACED WAY TO THE
SOUTH...OVER NORTHERN TEXAS. THINKING THE HIGHEST DEWPOINTS THAT
WOULD BE ADVECTED INTO THE AREA WOULD BE IN MID 50S. THE GFS SEEMS
TO BE A LITTLE MORE REALISTIC WITH DEWPOINTS CREEPING INTO THE MID
50S. THINKING THE HIGHEST MUCAPE VALUES WILL BE IN THE 500 TO 800
J/KG RANGE. SOME SURFACE BASED CAPE IS POSSIBLE NEAR THE WARM
FRONT. THE MAJOR LIMITING FACTOR FOR SEVERE THUNDERSTORM POTENTIAL
THIS AFTERNOON IS THE LACK OF MOISTURE/CAPE. THERE MAY BE A BRIEF
WINDOW FOR SEVERE THUNDERSTORMS OVER FAR SOUTHWEST WISCONSIN INTO
NORTHEAST IOWA. PLENTY OF SHEAR FOR SUPERCELLS. THINKING THE MAIN
THREATS WILL BE LARGE HAIL AND DAMAGING WINDS. IF A SURFACE BASED
STORM COULD DEVELOP ALONG THE FRONT...THERE COULD BE A VERY SHORT
WINDOW OF OPPORTUNITY FOR AN ISOLATED TORNADO...BUT IT APPEARS
UNLIKELY AT THIS TIME. WILL HAVE TO KEEP A VERY CLOSE WATCH ALONG
THE WARM FRONT THIS AFTERNOON TO SEE HOW SURFACE DEWPOINTS RESPOND
AS SOUTHERLY FLOW INCREASES INTO THE FRONT. HIGHS TODAY ARE
EXPECTED TO BE A LITTLE COOLER THAN YESTERDAY WITH THE CLOUDS AND
PRECIPITATION OVER THE AREA. PLAN ON HIGHS RANGING FROM THE MID TO
UPPER 60S.
THE WARM FRONT WILL LIFT NORTH ACROSS THE FORECAST AREA TONIGHT
THROUGH EARLY TUESDAY MORNING. 925 MB WARM AIR ADVECTION INCREASES
ACROSS THE FORECAST AREA IN THE WAKE OF THE WARM FRONT...IN THE WARM
SECTOR. DRY AIR ALOFT MOVES IN WITHIN THE WARM SECTOR AND LOOKS TO
EFFECTIVELY CAP THE ENVIRONMENT. HOWEVER...THE NAM IS SUGGESTING
THERE COULD BE ELEVATED CAPE. LIFTING FROM 900 MB YIELDS AROUND 700
J/KG CAPE. DECIDED TO KEEP THE SHOWER AND THUNDERSTORM CHANCES GOING
TONIGHT MAINLY AFTER 06Z. LOWS TONIGHT WILL BE ON THE MILD
SIDE...ESPECIALLY IN THE WAKE OF THE WARM FRONT...WITH LOWS IN THE
MID TO UPPER 50S.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 354 AM CDT MON APR 29 2013
THE UPPER TROUGH WILL CONTINUE TO DIG INTO THE CENTRAL CONUS ON
TUESDAY. MEANWHILE...SURFACE LOW PRESSURE IS EXPECTED TO DEEPEN AND
LIFT NORTH ACROSS NORTHERN MINNESOTA AND EVENTUALLY INTO WESTERN
ONTARIO. A COLD FRONT LOOKS TO PUSH SOUTHEAST ACROSS THE UPPER
MISSISSIPPI RIVER VALLEY THROUGH THE DAY ON TUESDAY...WITH SHOWERS
AND THUNDERSTORMS DEVELOPING ALONG THE FRONT MAINLY DURING THE
AFTERNOON HOURS. TEMPERATURES WILL WARM RATHER NICELY AHEAD OF THE
COLD FRONT...WITH HIGHS CLIMBING TO AROUND 80 DEGREES ACROSS
PORTIONS OF NORTHEAST IOWA THROUGH SOUTHWEST WISCONSIN. THE
NAM/GFS/GEM ARE IN FAIRLY DECENT AGREEMENT...SHOWING CONVECTION
DEVELOPING ALONG THE FRONT LATE TUESDAY AFTERNOON INTO TUESDAY
EVENING. THE NAM SEEMS WAY TO AGGRESSIVE WITH ITS DEWPOINTS TUESDAY
AFTERNOON SHOWING SURFACE DEWPOINTS CLIMBING INTO THE MID 60S. MID
TO UPPER 50S SEEM MORE REASONABLE AND THIS IS WHAT IS BEING
ADVERTISED BY THE GEM...WITH 0-3 MUCAPE VALUES AROUND 1500 J/KG. 0-6
KM SHEAR VALUES AROUND 40 KTS WOULD SUPPORT THE POTENTIAL FOR SEVERE
THUNDERSTORMS. PLAN ON SHOWERS AND STORMS ERUPTING ALONG THE FRONT
DURING THE AFTERNOON HOURS. SOME OF THE STORMS MAY BECOME SEVERE
WITH LARGE HAIL AND DAMAGING WINDS THE MAIN THREATS. THE TROUGH
CONTINUES TO DIG TUESDAY NIGHT INTO WEDNESDAY WITH A DEFORMATION
ZONE SETTING UP ACROSS THE UPPER MIDWEST...STRETCHING FROM EASTERN
NEBRASKA NORTHEAST THROUGH THE UPPER MISSISSIPPI RIVER VALLEY REGION
AND NORTH INTO CENTRAL ONTARIO. A VERY IMPRESSIVE FRONTOGENESIS ZONE
SETS UP ACROSS THE AREA TUESDAY NIGHT AND SITS RIGHT OVER THE
FORECAST AREA WEDNESDAY INTO THURSDAY. LOOKING AT FORECAST MODEL
CROSS SECTIONS RUNNING FROM EAST TO WEST ACROSS THE AREA...A VERY
IMPRESSIVE FRONTOGENESIS ZONE SETS UP OVER THE REGION AND EXTENDS
FROM 875 MB THROUGH 500 MB...WITH NEGATIVE EPV POSITIONED RIGHT OVER
THE FRONTOGENESIS ZONE. THIS ZONE STAYS OVER THE AREA ALL THE WAY
INTO THURSDAY. THIS WILL LEAD TO A PROLONGED PERIOD OF
PRECIPITATION OVER THE AREA WHICH COULD BE MODERATE TO HEAVY AT
TIMES. DRY AND COOL NORTHERLY FLOW INTO THE REGION THEN RAISES THE
QUESTION OF PRECIPITATION TYPE. DEPENDING ON WHICH MODEL SOLUTION
VERIFIES...IT APPEARS THAT THE PRECIPITATION SHOULD FALL AS RAIN
TUESDAY NIGHT AND THROUGH MOST OF THE DAY ON WEDNESDAY THEN SWITCH
OVER TO A RAIN SNOW MIX WEDNESDAY NIGHT INTO EARLY THURSDAY
MORNING. A RAIN SNOW MIX IS POSSIBLE AGAIN THURSDAY NIGHT...THEN
THE PRECIPITATION WILL SWITCH BACK OVER TO ALL RAIN DURING THE DAY
ON FRIDAY AS THE TROUGH CLOSES INTO AN UPPER LOW OVER MISSOURI AND
WARMER AIR FLOWS BACK TO THE NORTH. SNOW ACCUMULATIONS ARE
POSSIBLE LATE WEDNESDAY NIGHT AND AGAIN THURSDAY NIGHT. AT THIS
TIME IT APPEARS A SLUSHY 1-3 INCHES IS POSSIBLE MAINLY ON GRASS
SURFACES. WILL ALSO HAVE TO KEEP A CLOSE EYE ON PRECIPITATION
TYPE...ESPECIALLY THURSDAY NIGHT INTO FRIDAY MORNING AS THE WARM
LAYER SURGES BACK TO THE NORTH. A BRIEF PERIOD OF SLEET IS
POSSIBLE BEFORE TEMPERATURES NEAR THE SURFACE WARM ABOVE FREEZING.
MODEL SOLUTIONS START TO DIVERGE THIS WEEKEND WITH THE HANDLING OF
THE LOW AS IT CUTS OFF. THE GEM TAKES THE LOW INTO THE SOUTHERN
PLAINS...WHILE THE ECMWF LIFTS IT NORTHWEST THROUGH THE DAKOTAS.
THE GFS KEEPS IT STALLED OVER MISSOURI THEN FINALLY LIFTS IT NORTH
INTO THE GREAT LAKES LATE ON SUNDAY. AFTER A COOL PERIOD THURSDAY
AND FRIDAY...WHERE HIGHS WILL ONLY BE IN THE LOWER 40S...SLIGHTLY
WARMER TEMPERATURES ARE POSSIBLE THIS WEEKEND DESPITE CHANCES FOR
RAIN...WITH HIGHS IN THE LOWER TO MIDDLE 50S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1240 PM CDT MON APR 29 2013
A LOW PRESSURE SYSTEM LOCATED OVER EASTERN NEBRASKA WILL MOVE EAST
NORTHEAST ACROSS IOWA THIS AFTERNOON AND EVENING. AT THIS TIME...THE
BEST SHOWER AND THUNDERSTORM THREAT LOOKS TO BE SOUTH OF TAF SITES
ACROSS NORTHEAST IOWA AND SOUTHWEST WISCONSIN. WITH THE LOSS OF
DIURNAL HEATING THIS AFTERNOON...EXPECT THE 2500 TO 5000 CUMULUS
DECK NEAR INTERSTATE 90 TO GRADUALLY DISSIPATE BETWEEN 29.22Z
AND 30.04Z.
AS A COLD FRONT APPROACHES THE AREA ON TUESDAY MORNING...EXPECT A
BROKEN 10 TO 15K FOOT DECK OF CLOUDS TO MOVE INTO KRST AROUND
30.16Z. IN ADDITION AS DIURNAL HEATING OCCURS...EXPECT THE WINDS
TO GUST INTO THE 25 TO 30 KNOT RANGE AT BOTH TAF SITES AFTER
30.15Z.
&&
.HYDROLOGY...
ISSUED AT 354 AM CDT MON APR 29 2013
HEAVY RAINFALL IS POSSIBLE THIS WEEK AS A SYSTEM STALLS OUT
ACROSS THE REGION TOWARD MID WEEK. FORECAST GUIDANCE SUGGESTS
TOTAL RAINFALL AMOUNTS OF 2 TO 4 INCHES ARE POSSIBLE BY THE END OF
THE WEEK. SOME OF THIS PRECIPITATION COULD FALL AS A SLEET/SNOW
MIX. IF THESE RAINFALL AMOUNTS ARE REALIZED...THERE WOULD BE AN
INCREASE IN RIVER LEVELS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM....WETENKAMP
AVIATION...BOYNE
HYDROLOGY....WETENKAMP
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
652 AM CDT MON APR 29 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 354 AM CDT MON APR 29 2013
A VERY ACTIVE WEATHER PATTERN IN STORE FOR THE REGION THIS WEEK.
FIRST OFF...WILL BE WATCHING A WEAK COLD FRONT SAGGING SOUTH ACROSS
THE AREA TODAY. TWO SHORTWAVE TROUGHS ARE EXPECTED TO MOVE ACROSS
THE UPPER MISSISSIPPI RIVER VALLEY TODAY AND INTERACT WITH THE FRONT
AS IT EDGES SOUTH...SPARKING OFF SHOWERS AND THUNDERSTORMS. THE
FIRST LEADING SHORTWAVE WAS RACING EAST ACROSS SOUTH DAKOTA EARLY
THIS MORNING WHILE THE SECOND WAVE WAS MOVING EAST ACROSS WYOMING.
THE LEADING TROUGH WILL MOVE ACROSS THE REGION THIS MORNING
KEEPING SHOWERS AND ISOLATED THUNDERSTORMS GOING THROUGH MUCH OF
THE MORNING HOURS. THE TRAILING WAVE WILL ARRIVE EARLY THIS
AFTERNOON...PUSHING ACROSS NORTHERN IOWA THEN INTO SOUTHERN
WISCONSIN BY LATE AFTERNOON INTO THE EARLY EVENING HOURS. THE
FRONT IS EXPECTED TO STALL OUT ACROSS NORTHERN IOWA THROUGH
SOUTHERN WISCONSIN LATE THIS AFTERNOON AND THEN START TO LIFT
NORTH AND ACT AS A WARM FRONT LATE THIS AFTERNOON INTO THIS
EVENING AS VIGOROUS TROUGH DIVES INTO THE NORTHWEST CONUS. AN
INTERESTING ENVIRONMENT SETS UP OVER NORTHEAST IOWA AND FAR
SOUTHWEST WISCONSIN LATE THIS AFTERNOON AS THIS WARM FRONT TAKES
SHAPE. KBLR NAM FORECAST SOUNDINGS SHOW RATHER IMPRESSIVE SHEAR
PROFILES...WITH 0-6 KM BULK SHEAR OF 45 TO 50 KTS...AND 0-1 KM
BULK SHEAR OF 20 TO 25 KTS. CURVATURE ALSO NOTED IN THE HODOGRAPH
FROM THE SURFACE TO 2 KM. THE RAP IS ALSO SHOWING SIMILAR SHEAR
PROFILES. THE NAM IS INDICATING NEARLY 1500 J/KG 0-3KM MUCAPE
VALUES ACROSS THESE AREAS THIS AFTERNOON...BUT THIS IS LIKELY WAY
OVERDONE GIVEN THE NAM IS SHOWING DEWPOINTS CLIMBING TO 60 DEGREES
THIS AFTERNOON. 60 DEGREE DEWPOINTS ARE DISPLACED WAY TO THE
SOUTH...OVER NORTHERN TEXAS. THINKING THE HIGHEST DEWPOINTS THAT
WOULD BE ADVECTED INTO THE AREA WOULD BE IN MID 50S. THE GFS SEEMS
TO BE A LITTLE MORE REALISTIC WITH DEWPOINTS CREEPING INTO THE MID
50S. THINKING THE HIGHEST MUCAPE VALUES WILL BE IN THE 500 TO 800
J/KG RANGE. SOME SURFACE BASED CAPE IS POSSIBLE NEAR THE WARM
FRONT. THE MAJOR LIMITING FACTOR FOR SEVERE THUNDERSTORM POTENTIAL
THIS AFTERNOON IS THE LACK OF MOISTURE/CAPE. THERE MAY BE A BRIEF
WINDOW FOR SEVERE THUNDERSTORMS OVER FAR SOUTHWEST WISCONSIN INTO
NORTHEAST IOWA. PLENTY OF SHEAR FOR SUPERCELLS. THINKING THE MAIN
THREATS WILL BE LARGE HAIL AND DAMAGING WINDS. IF A SURFACE BASED
STORM COULD DEVELOP ALONG THE FRONT...THERE COULD BE A VERY SHORT
WINDOW OF OPPORTUNITY FOR AN ISOLATED TORNADO...BUT IT APPEARS
UNLIKELY AT THIS TIME. WILL HAVE TO KEEP A VERY CLOSE WATCH ALONG
THE WARM FRONT THIS AFTERNOON TO SEE HOW SURFACE DEWPOINTS RESPOND
AS SOUTHERLY FLOW INCREASES INTO THE FRONT. HIGHS TODAY ARE
EXPECTED TO BE A LITTLE COOLER THAN YESTERDAY WITH THE CLOUDS AND
PRECIPITATION OVER THE AREA. PLAN ON HIGHS RANGING FROM THE MID TO
UPPER 60S.
THE WARM FRONT WILL LIFT NORTH ACROSS THE FORECAST AREA TONIGHT
THROUGH EARLY TUESDAY MORNING. 925 MB WARM AIR ADVECTION INCREASES
ACROSS THE FORECAST AREA IN THE WAKE OF THE WARM FRONT...IN THE WARM
SECTOR. DRY AIR ALOFT MOVES IN WITHIN THE WARM SECTOR AND LOOKS TO
EFFECTIVELY CAP THE ENVIRONMENT. HOWEVER...THE NAM IS SUGGESTING
THERE COULD BE ELEVATED CAPE. LIFTING FROM 900 MB YIELDS AROUND 700
J/KG CAPE. DECIDED TO KEEP THE SHOWER AND THUNDERSTORM CHANCES GOING
TONIGHT MAINLY AFTER 06Z. LOWS TONIGHT WILL BE ON THE MILD
SIDE...ESPECIALLY IN THE WAKE OF THE WARM FRONT...WITH LOWS IN THE
MID TO UPPER 50S.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 354 AM CDT MON APR 29 2013
THE UPPER TROUGH WILL CONTINUE TO DIG INTO THE CENTRAL CONUS ON
TUESDAY. MEANWHILE...SURFACE LOW PRESSURE IS EXPECTED TO DEEPEN AND
LIFT NORTH ACROSS NORTHERN MINNESOTA AND EVENTUALLY INTO WESTERN
ONTARIO. A COLD FRONT LOOKS TO PUSH SOUTHEAST ACROSS THE UPPER
MISSISSIPPI RIVER VALLEY THROUGH THE DAY ON TUESDAY...WITH SHOWERS
AND THUNDERSTORMS DEVELOPING ALONG THE FRONT MAINLY DURING THE
AFTERNOON HOURS. TEMPERATURES WILL WARM RATHER NICELY AHEAD OF THE
COLD FRONT...WITH HIGHS CLIMBING TO AROUND 80 DEGREES ACROSS
PORTIONS OF NORTHEAST IOWA THROUGH SOUTHWEST WISCONSIN. THE
NAM/GFS/GEM ARE IN FAIRLY DECENT AGREEMENT...SHOWING CONVECTION
DEVELOPING ALONG THE FRONT LATE TUESDAY AFTERNOON INTO TUESDAY
EVENING. THE NAM SEEMS WAY TO AGGRESSIVE WITH ITS DEWPOINTS TUESDAY
AFTERNOON SHOWING SURFACE DEWPOINTS CLIMBING INTO THE MID 60S. MID
TO UPPER 50S SEEM MORE REASONABLE AND THIS IS WHAT IS BEING
ADVERTISED BY THE GEM...WITH 0-3 MUCAPE VALUES AROUND 1500 J/KG. 0-6
KM SHEAR VALUES AROUND 40 KTS WOULD SUPPORT THE POTENTIAL FOR SEVERE
THUNDERSTORMS. PLAN ON SHOWERS AND STORMS ERUPTING ALONG THE FRONT
DURING THE AFTERNOON HOURS. SOME OF THE STORMS MAY BECOME SEVERE
WITH LARGE HAIL AND DAMAGING WINDS THE MAIN THREATS. THE TROUGH
CONTINUES TO DIG TUESDAY NIGHT INTO WEDNESDAY WITH A DEFORMATION
ZONE SETTING UP ACROSS THE UPPER MIDWEST...STRETCHING FROM EASTERN
NEBRASKA NORTHEAST THROUGH THE UPPER MISSISSIPPI RIVER VALLEY REGION
AND NORTH INTO CENTRAL ONTARIO. A VERY IMPRESSIVE FRONTOGENESIS ZONE
SETS UP ACROSS THE AREA TUESDAY NIGHT AND SITS RIGHT OVER THE
FORECAST AREA WEDNESDAY INTO THURSDAY. LOOKING AT FORECAST MODEL
CROSS SECTIONS RUNNING FROM EAST TO WEST ACROSS THE AREA...A VERY
IMPRESSIVE FRONTOGENESIS ZONE SETS UP OVER THE REGION AND EXTENDS
FROM 875 MB THROUGH 500 MB...WITH NEGATIVE EPV POSITIONED RIGHT OVER
THE FRONTOGENESIS ZONE. THIS ZONE STAYS OVER THE AREA ALL THE WAY
INTO THURSDAY. THIS WILL LEAD TO A PROLONGED PERIOD OF
PRECIPITATION OVER THE AREA WHICH COULD BE MODERATE TO HEAVY AT
TIMES. DRY AND COOL NORTHERLY FLOW INTO THE REGION THEN RAISES THE
QUESTION OF PRECIPITATION TYPE. DEPENDING ON WHICH MODEL SOLUTION
VERIFIES...IT APPEARS THAT THE PRECIPITATION SHOULD FALL AS RAIN
TUESDAY NIGHT AND THROUGH MOST OF THE DAY ON WEDNESDAY THEN SWITCH
OVER TO A RAIN SNOW MIX WEDNESDAY NIGHT INTO EARLY THURSDAY
MORNING. A RAIN SNOW MIX IS POSSIBLE AGAIN THURSDAY NIGHT...THEN
THE PRECIPITATION WILL SWITCH BACK OVER TO ALL RAIN DURING THE DAY
ON FRIDAY AS THE TROUGH CLOSES INTO AN UPPER LOW OVER MISSOURI AND
WARMER AIR FLOWS BACK TO THE NORTH. SNOW ACCUMULATIONS ARE
POSSIBLE LATE WEDNESDAY NIGHT AND AGAIN THURSDAY NIGHT. AT THIS
TIME IT APPEARS A SLUSHY 1-3 INCHES IS POSSIBLE MAINLY ON GRASS
SURFACES. WILL ALSO HAVE TO KEEP A CLOSE EYE ON PRECIPITATION
TYPE...ESPECIALLY THURSDAY NIGHT INTO FRIDAY MORNING AS THE WARM
LAYER SURGES BACK TO THE NORTH. A BRIEF PERIOD OF SLEET IS
POSSIBLE BEFORE TEMPERATURES NEAR THE SURFACE WARM ABOVE FREEZING.
MODEL SOLUTIONS START TO DIVERGE THIS WEEKEND WITH THE HANDLING OF
THE LOW AS IT CUTS OFF. THE GEM TAKES THE LOW INTO THE SOUTHERN
PLAINS...WHILE THE ECMWF LIFTS IT NORTHWEST THROUGH THE DAKOTAS.
THE GFS KEEPS IT STALLED OVER MISSOURI THEN FINALLY LIFTS IT NORTH
INTO THE GREAT LAKES LATE ON SUNDAY. AFTER A COOL PERIOD THURSDAY
AND FRIDAY...WHERE HIGHS WILL ONLY BE IN THE LOWER 40S...SLIGHTLY
WARMER TEMPERATURES ARE POSSIBLE THIS WEEKEND DESPITE CHANCES FOR
RAIN...WITH HIGHS IN THE LOWER TO MIDDLE 50S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 652 AM CDT MON APR 29 2013
APPEARS THE TAF SITES WILL CATCH A BREAK FROM SHRA AND ANY REDUCED
CIGS/VSBYS THIS MORNING WITH THE FORCING/INSTABILITY SHIFTING SOUTH
OF THE AREA. OVERNIGHT RAINS AT KRST PLUS LIGHT WINDS PRODUCING SOME
BR/FG ACROSS SOUTHEAST MN AND ADDED SOME BR MENTION TO KRST EARLY
THIS MORNING. AFTER THAT THOUGH...CONFIDENCE REMAINS ON THE LOW SIDE
FOR THE AFTERNOON AND TONIGHT AS FAR AS CONVECTION CHANCES AND
EVOLUTION AT THE TAF SITES. A STALLED/WEAKENING FRONTAL BOUNDARY
WILL REMAIN IN THE AREA...AND BE A POTENTIAL TRIGGER FOR MORE
SHRA/TSRA THIS AFTERNOON/EVENING. CONVECTION POTENTIAL IS GOING TO
DEPEND ON HOW MUCH LOWER LEVEL MOISTURE AND INSTABILITY CAN OR DOES
MOVE NORTHWARD INTO THE AREA TODAY. GIVEN INCONSISTENT MODEL SIGNALS
FOR THE MOISTURE INCREASE AND ABILITY OF THE STALLED/WEAKENING
BOUNDARY TO TRIGGER CONVECTION...ONLY INCLUDED A VCSH MENTION AT THE
TAF SITES IN THE 22-02Z TIME PERIOD FOR NOW.
BOUNDARY LIFTS NORTH AS A WARM FRONT TONIGHT...WITH THE INCREASING
LOWER LEVEL MOISTURE EXPECTED TO SPREAD NORTH ACROSS THE AREA. STILL
PLENTY OF POSSIBLE SCENARIOS FOR CONVECTION EVOLUTION TONIGHT INTO
TUE. WITH THE INCREASE OF MOISTURE AND MOISTURE CONVERGENCE LATE
TONIGHT...INCLUDED A VCSH MENTION AFTER 09Z FOR NOW UNTIL A MORE
CONSISTENT SIGNAL IS SEEN. ADDED A LATE NIGHT MVFR BR MENTION AT
KRST AS WELL DUE TO THE SOUTHEAST FLOW AND MOISTURE INCREASE.
&&
.HYDROLOGY...
ISSUED AT 354 AM CDT MON APR 29 2013
HEAVY RAINFALL IS POSSIBLE THIS WEEK AS A SYSTEM STALLS OUT
ACROSS THE REGION TOWARD MID WEEK. FORECAST GUIDANCE SUGGESTS
TOTAL RAINFALL AMOUNTS OF 2 TO 4 INCHES ARE POSSIBLE BY THE END OF
THE WEEK. SOME OF THIS PRECIPITATION COULD FALL AS A SLEET/SNOW
MIX. IF THESE RAINFALL AMOUNTS ARE REALIZED...THERE WOULD BE AN
INCREASE IN RIVER LEVELS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM....WETENKAMP
AVIATION.....RRS
HYDROLOGY....WETENKAMP
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1157 PM CDT SUN APR 28 2013
.UPDATE...
ISSUED AT 558 PM CDT SUN APR 28 2013
CURRENTLY A NARROW LINE OF CONVECTION HAS INITIATED ALONG THE COLD
FRONT IN MINNESOTA FROM RUSH CITY TO MINNEAPOLIS AND ST JAMES.
LAPS ANALYSIS SHOWED MLCAPE VALUES OF 250-600 J/KG...MOSTLY RIGHT
ALONG THE FRONT. KMPX RADAR IMAGERY DOES SUGGEST THAT THE LINE OF
CONVECTION MAY HAVE JUMPED OFF THE FRONT RECENTLY...THOUGH.
MEANWHILE...OVER THE FORECAST AREA...SOME RIDGING HAS BUILT IN
ALOFT PER RAP ANALYSIS...HELPING TO CLEAR SKIES OUT.
PRECIPITATION CHANCES CONTINUE TO BE THE FOCUS TONIGHT. THE
28.12Z REGIONAL CANADIAN AND 28.19/20/21Z HRRR RUNS HAVE BEEN
DOING A GREAT JOB WITH THE CONVECTION ON THE FRONT. ALL OF THESE
MODELS SUGGEST A WEAKENING TREND AS THEY PUSH EAST THROUGH THE
EVENING. THIS MAKES SENSE AS THEY SEEM TO BE DIURNALLY ASSISTED
WITH THE CAPE THAT BUILT AHEAD OF THE FRONT. ONCE DIURNAL COOLING
TAKES PLACE...INSTABILITY WILL WANE AND THUS THE STORMS AS WELL.
PERHAPS A FEW MAY MAKE IT INTO NORTHWEST SECTIONS OF THE FORECAST
AREA...ENOUGH TO WARRANT 20-30 PERCENT CHANCES...LOWER THAN THE
PREVIOUS FORECAST. SEEING SOME OF THE CONVECTION JUMPING OFF THE
FRONT ALSO IS WORRISOME TO HOLD IT TOGETHER BECAUSE INSTABILITY
WANES PRETTY QUICK. THERE COULD BE A GENERALLY DRY PERIOD THEN
UNTIL LATE IN THE NIGHT...WHICH IS WHEN THE COLD FRONT SLIDES INTO
THE AREA. BEHIND THIS FRONT...TWO FORCING MECHANISMS SHOULD HELP
DEVELOP PRECIPITATION...
1. A SHORTWAVE OVER NORTHWEST WYOMING PUSHING EAST INTO EASTERN
SOUTH DAKOTA BY LATE IN THE NIGHT...YIELDING SOME DPVA DOWNSTREAM
INTO NORTHERN IOWA AND SOUTHERN MINNESOTA.
2. MID-LEVEL FRONTOGENESIS IN PLACE BEHIND THE FRONT. RADAR SHOWS
THIS FRONTOGENESIS ALREADY BY A BAND OF SHOWERS FROM NEAR ABERDEEN
SOUTH DAKOTA TO DULUTH MN.
THUS STILL HAVE KEPT SOME HIGHER PRECIPITATION CHANCES FOR LATE IN
THE NIGHT INTO MONDAY MORNING...ESPECIALLY OVER NORTHEAST IOWA
WHERE CONSENSUS EXISTS FROM ALL MODELS FOR PRECIPITATION TO OCCUR.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 327 PM CDT SUN APR 28 2013
THE MAIN FOCUS FOR TONIGHT INTO MONDAY IS WITH A TWO TIERED SYSTEM
AND THE PRECIPITATION CHANCES THAT COME ALONG WITH IT. THE FIRST
WAVE APPROACHES THE REGION THIS EVENING IN THE FORM OF A SURFACE
COLD FRONT THAT IS CURRENTLY ANALYZED IN WESTERN MINNESOTA. MUCH
OF THE 28.12Z GUIDANCE ARE FORECASTING TOO HIGH OF SURFACE DEW
POINTS...IN THE LOW TO MID 50S WHEN CURRENT OBS SHOW MID
40S...WHICH IN TURN IS MAKING THE INSTABILITY IN THESE MODELS TOO
HIGH. THIS IS CAUSING A LOT OF THE GUIDANCE TO COME UP WITH A
LARGE AREA OF CONVECTION THAT DEVELOPS THIS EVENING AHEAD OF THE
FRONT AND BRINGS IT THROUGH THE REGION IN AN DIMINISHING FASHION
AS THE INSTABILITY WANES OVERNIGHT. THAT TREND IS OKAY...BUT AM
NOT VERY CONFIDENT THAT THIS CONVECTION WILL BE AS WIDESPREAD AS
GUIDANCE SUGGESTS. THE 28.12Z ARW EAST/WEST MODELS SEEM TO DO THE
BEST JOB AT LIMITING THE CLIMBING DEW POINTS AND KEEP 0-3KM MUCAPE
IN THE 200-400 J/KG RANGE OVERNIGHT AND MATCHES BEST TO THESE
THOUGHTS OF MORE SCATTERED THAN WIDESPREAD CONVECTION OVERNIGHT.
WITH JUST A FEW HUNDRED J/KG OF CAPE TO WORK WITH...HAVE LIMITED
THE THUNDER COVERAGE TO BEING ISOLATED TONIGHT. THERE IS SOME
INCREASING MID LEVEL WINDS AS THIS FRONT APPROACHES...SO SHEAR MAY
BE DECENT ENOUGH THAT...COMBINED WITH SOME LOW FREEZING
LEVELS...THERE COULD BE SOME SMALL HAIL THAT OCCURS WITH A FEW OF
THE STORMS BUT NOTHING THAT WOULD BE CONSIDERED SEVERE.
THE MAIN MID LEVEL TROUGH DIVES DOWN ACROSS THE REGION TOMORROW
MORNING AND IS EXPECTED TO DEVELOP A MORE WIDESPREAD AREA OF
CONVECTION ALONG THE WEAKENING SURFACE FRONT. THIS MID LEVEL
TROUGH IS CURRENTLY NOTED ON GOES WATER VAPOR IMAGERY EXTENDING
EAST TO WEST FROM SOUTHWEST ONTARIO INTO SOUTHEAST MONTANA. AS
THIS TROUGH SAGS SOUTHEAST TOMORROW...SOME DIFFERENCES ARISE
BETWEEN THE 28.12Z MESO AND SYNOPTIC SCALE MODELS. THE 28.12Z
NAM/GFS/ECMWF/GEM ALL SHOW SOME STRONG LOW LEVEL MOISTURE
TRANSPORT NOSING UP INTO EASTERN IOWA BY LATE MORNING THAT ALSO
BRING SURFACE DEW POINTS UP INTO THE 60S AHEAD OF THE SURFACE/LOW
LEVEL LOW. THIS BRINGS SFC/0-3KM MUCAPE UP TO ABOVE 2000 J/KG AND
DEVELOPS A WIDESPREAD AREA OF CONVECTION ALONG THE NOSE OF THE LOW
LEVEL JET. MEANWHILE...28.12Z ARW/NMM ARE MUCH MORE TAME WITH THE
MOISTURE RETURN/DEW POINTS/INSTABILITY AND CONVECTIVE DEVELOPMENT.
HAVE KEPT THE LIKELY PRECIPITATION CHANCES GOING FOR NORTHEAST
IOWA/SOUTHWEST WISCONSIN TOMORROW WHERE THIS CONVECTION IS A BIT
MORE CERTAIN...BUT THINK THAT THE SYNOPTIC MODELS ARE A TAD
OVERDONE. IF THE MOISTURE RETURN CAN DEVELOP AS ADVERTISED ON
THESE SYNOPTIC MODELS...WILL HAVE TO WATCH FOR A BRIEF PERIOD OF
SEVERE STORMS THAT COULD PRODUCE SOME LARGE HAIL/GUSTY WINDS.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 327 PM CDT SUN APR 28 2013
THE 28.12Z GUIDANCE REMAINS STUBBORN WITH NO DIFFERING TRENDS
NOTED BETWEEN THIS RUN AND THE 28.00Z RUN FOR A COLD FRONT THAT
WILL MOVE THROUGH ON TUESDAY. AHEAD OF THIS FRONT
ON MONDAY NIGHT...THE LOW LEVEL JET/MOISTURE TRANSPORT WILL PUSH
BACK TO THE NORTH AHEAD OF THE FRONT AND COULD SPARK OFF SOME
CONVECTION AS IT LIFTS NORTHWARD. FOR TUESDAY...THE 28.12Z ECMWF
REMAINS THE SLOW OUTLIER WITH THE EASTWARD PROGRESSION OF THE
SURFACE COLD FRONT ON TUESDAY AND PRESENTS THE WARMEST SOLUTION
FOR TEMPERATURES. BY 00Z WEDNESDAY...THE 28.12Z NAM/GFS BOTH HAVE
THIS FRONT INTO NORTHWEST ILLINOIS WHILE THE ECMWF STILL HAS IT
BACK IN NORTHWEST WISCONSIN/JUST CLEARING SOUTHEAST MINNESOTA.
WITH LOW LEVEL MOISTURE TRANSPORT INCREASING AHEAD OF THIS FRONT
ON TUESDAY AND DECENT LOW LEVEL LIFT ALONG THE FRONT...SOME SEVERE
WEATHER IS POSSIBLE IN THE WARM SECTOR TUESDAY. WHERE THAT WARM
SECTOR IS ALIGNED BY MID AFTERNOON IS UNCERTAIN STILL...BUT WILL
HAVE TO WATCH FOR WHICH WAY THIS FRONT TRENDS. DUE TO THERE NOT
BEING MUCH IN THE WAY OF CHANGES IN THE GUIDANCE...HAVE NOT MADE
MANY ADJUSTMENTS TO THE GOING FORECAST OVER THIS PERIOD.
AFTER THIS COLD FRONT MOVES THROUGH BY TUESDAY NIGHT IT WILL THEN
STALL OUT TO THE EAST OF THE REGION AS A MID TO UPPER LEVEL TROUGH
AMPLIFIES ACROSS THE CENTRAL US TOWARD THE MIDDLE OF THE WEEK.
THIS TROUGH GETS CUT OFF FROM THE FLOW WITH THE CORE OF THE LOW
SITTING RIGHT OVER THE UPPER MISSISSIPPI RIVER VALLEY THROUGH NEXT
WEEKEND. STRONG FORCING WILL DEVELOP ON WEDNESDAY IN RESPONSE TO
A STRENGTHENING LOW TO MID LEVEL BAND OF FRONTOGENESIS THAT FORMS
TO THE WEST OF THE SURFACE FRONT. WHILE THE 28.12Z ECMWF CONTINUES
TO BE AN OUTLIER WITH A WARMER SOLUTION FROM 700MB DOWN TO THE
SURFACE ON WEDNESDAY AND WANTS TO KEEP THE PRECIPITATION AS
MAINLY RAIN TO BEGIN...IT DOES APPEAR TO BE COMING AROUND TO BEING
COLD ENOUGH TO PRODUCE ALL SNOW FROM WEDNESDAY NIGHT INTO EARLY
THURSDAY. THIS IS ESPECIALLY THE CASE ACROSS SOUTHEAST MINNESOTA
AND NORTHEAST IOWA WHERE SOME SIGNIFICANT SNOW RATES AND
ACCUMULATIONS ARE POSSIBLE. 28.12Z GFS THERMAL PROFILES SHOW THAT
THE MAIN QUESTION IS WITH SURFACE TEMPERATURES AND HOW MUCH THEY
WILL COOL AS THE PRECIPITATION COMMENCES ON WEDNESDAY. THE HIGHEST
CONFIDENCE FOR ANY SNOW ACCUMULATION AT THIS POINT IS WEDNESDAY
NIGHT INTO THURSDAY MORNING AS THE COLDEST LOW LEVEL AIR COMES IN.
CURRENT FORECAST TEMPERATURES FOR WEDNESDAY INTO THURSDAY MAY END
UP BEING TOO HIGH...BUT FOR NOW HAVE DONE A SEMI-BLEND OF THE
28.12Z GFS/ECMWF.
BEYOND THIS FEATURE...THE 28.12Z GFS IS FASTER WITH CLEARING OUT
THE PRECIPITATION ON THURSDAY COMPARED TO THE ECMWF AND GEM WHICH
LINGER THE FRONTOGENETIC BAND OVER THE REGION THROUGH THE REST OF
THE WEEK AS THE MID LEVEL LOW GETS CUT OFF FROM THE FLOW. THIS MID
LEVEL AND SURFACE LOW RETROGRADE BACK INTO IOWA/MISSOURI BY NEXT
WEEKEND...WHICH MAY HELP TO BRING SOME SLIGHTLY WARMER AIR BACK
INTO THE REGION. OVERALL...EXPECTING PERIODS OF PRECIPITATION AS
THIS LOW SITS AND SPINS WITH SHORTWAVE TROUGHS ROTATING AROUND IT
THROUGH NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1157 PM CDT SUN APR 28 2013
CONFIDENCE REMAINS LOW FOR THE AVIATION FORECAST...PRIMARILY ON IF
PRECIPITATION WILL IMPACT THE TAF SITES. AS OF 05Z...A BAND OF
SHOWERS AND A FEW EMBEDDED THUNDERSTORMS STRETCHED FROM NORTHWEST
IOWA TO THE EAU CLAIRE AREA. THIS BAND SHOULD SINK SOUTH WITH
TIME...BUT THERE ARE CONFLICTING SIGNALS AS TO ITS SPEED AND
WHETHER IT WILL HOLD TOGETHER. A STRONGER SIGNAL SHOWS UP IN THE
12-18Z TIME PERIOD OF AN AREA OF SHOWERS AND SOME THUNDERSTORMS
FORMING OVER NORTHERN IOWA AND MARCHING NORTHEAST...POSSIBLY
CLIPPING THE TAF SITES. HAVE KEPT THE VCSH GOING BECAUSE OF THE
UNCERTAINTY...RUNNING FROM 06Z-15Z AT KRST AND 09-21Z AT KLSE.
EVEN IF SHOWERS IMPACT THE TAF SITES...CONDITIONS LOOK TO STAY
VFR. THE BIGGER CONCERN WOULD BE ANY THUNDERSTORMS...BUT GIVEN THE
ISOLATED NATURE OF THEM AND THE UNCERTAINTY ON SHOWERS IMPACTING
THE TAF SITES...HAVE NOT INCLUDED ANY THUNDER IN THE TAFS. DRYING
CONDITIONS LOOK TO TAKE HOLD FOR THE LATE AFTERNOON AND EVENING
HOURS AS THE FORCING FOR PRECIPITATION SHIFTS OFF TO THE EAST.
THE VFR CLOUDS IN PLACE MAY EVEN BREAK UP DURING THIS TIME.
ONE SIDE NOTE IS THAT BETWEEN NOW AND 09Z...CONDITIONS ARE
MARGINAL FOR LOW LEVEL WIND SHEAR AT KLSE. A SOUTHWESTERLY 30-35
KT JET EXISTS BETWEEN 1000-1500 FT AGL DURING THIS TIME. HAVE NOT
INCLUDED THE LOW LEVEL WIND SHEAR DUE TO AGAIN THE MARGINAL
NATURE.
&&
.HYDROLOGY...
ISSUED AT 327 PM CDT SUN APR 28 2013
POTENTIAL EXISTS FOR SOME HEAVY RAINFALL THIS WEEK AS A SYSTEM
STALLS OUT ACROSS THE REGION TOWARD MID WEEK. THERE IS SOME
QUESTION ABOUT WHAT THE PRECIPITATION TYPE WILL BE...BUT THE
FORECAST GUIDANCE IS SUGGESTING RAINFALL AMOUNTS OF OVER AN INCH
BY THE END OF THE WEEK. SHOULD THIS PRECIPITATION FALLS AS
RAIN...THERE COULD BE AN INCREASE IN LOCAL RIVER LEVELS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...AJ
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...AJ
HYDROLOGY...HALBACH
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
116 AM EDT WED MAY 1 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 432 PM EDT TUE APR 30 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD MID/UPPER LEVEL TROUGH
OVER THE NW CONUS RESULTING IN SW FLOW FROM THE CNTRL PLAINS TO THE
NRN GREAT LAKES. A VIGOROUS SHORTWAVE IN THIS SW FLOW ALOFT WAS
LIFTING NORTH INTO NW ONTARIO. AT THE SFC...LOW PRES WAS LOCATED
OVER NW ONTARIO WITH A COLD FRONT EXTENDING SOUTH INTO FAR WRN LAKE
SUPERIOR AND NW WI. A WARM FRONT WAS DRAPED ACROSS NCNTRL AND NE WI.
BULGE OF WARM DRY AIR AT AROUND 850 MB AS NOTED ON 12Z GRB SNDG AND
LATEST RAPID RUC SNDGS AT KIMT HAS PRODUCED SEVERAL HUNDRED J/KG OF
CIN....KEEPING ATMOSPHERE CAPPED ENOUGH TO PROHIBIT SHOWERS FROM
FORMING OVER MUCH OF THE FCST AREA SO FAR THIS AFTERNOON. JUST IN
LATEST RADAR VOLUME SCAN STARTING TO SEE A FEW SHOWERS POPPING OVER
HOUGHTON COUNTY BUT WITH ONLY AROUND 200-300 J/KG OF MLCAPE NOT
REALLY EXPECTED MUCH IN WAY OF THUNDER.
AS MODELS SHOW FRONT MOVG SLOWLY EAST INTO CENTRAL FCST AREA...RAP
RUC SNDGS FOR KIMT SUGGESTS CAP ALOFT MAY ERODE JUST ENOUGH TO ALLOW
FOR SOME ISOLD TO SCT SHRA/TSRA TO FORM TOWARD SUNSET OVER CNTRL
FCST AREA. INCREASING 800-700 MB FGEN IN RESPONSE TO RIGHT ENTRANCE
REGION FORCING IN 140+ KT 3H JET OVER NRN PLAINS AND WRN ONTARIO
WILL BE MAIN DRIVING FORCE FOR BAND OF RAIN WHICH MODELS PROJECT TO
FORM LATE THIS EVENING AND EARLY OVERNIGHT OVER CENTRAL PORTION OF
THE FCST AREA. THIS BAND OF PCPN IS THEN PROGGED BY MODELS TO SHIFT
OVER THE WRN CWA LATE TONIGHT INTO WED AS BEST FGEN FORCING SHIFTS
WEST. LOWS TONIGHT WILL BE IN THE 40S UNDER MOSTLY CLOUDY SKIES.
MODEL AVG QPF INDICATES THAT PORTIONS OF GOGEBIC AND ONTONAGON
COUNTIES COULD SEE UP TO QUARTER INCH OF PCPN LATE TONIGHT INTO
WEDNESDAY. COLDER AIR (8H TEMPS DROPPING BLO 0C )SEEPING INTO THE
WRN CWA COULD CAUSE SOME SNOW TO MIX IN WITH RAIN BY LATE WED
AFTERNOON AS TEMPS FALL INTO THE MID TO UPPER 30S TOWARD EVENING.
N-NW ONSHORE FLOW OFF COOL LAKE SUPERIOR ALONG CLOUDY SKIES WILL
RESULT IN MAX TEMPS ON THE LOWER END OF MODEL GUIDANCE FOR WEDNESDAY
WITH HIGHS RANGING FROM THE LOWER TO MID 40S ALONG LAKE SUPERIOR TO
GENERALLY THE LOWER TO MID 50S EAST AND SCNTRL.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 432 PM EDT TUE APR 30 2013
FORECAST CONTINUES TO DEAL WITH THE UPPER TROUGH DEVELOPING IN THE
IN THE NORTHERN PLAINS AND WHAT HAPPENS TO IT AS IT CUTS OFF AROUND
THE END OF THIS WEEK AND DRIFTS THIS WEEKEND.
TO START THE PERIOD...THE FORECAST CONCERN IS THE STALLED 850MB
FRONT STRETCHING FROM NORTHERN LAKE SUPERIOR THROUGH SOUTHEAST
MINNESOTA AND INTO THE CENTRAL PLAINS AS THE UPPER TROUGH SLOWLY
SHIFTS EAST THROUGH THE NORTHERN PLAINS. THE POSITION OF THE FRONT
WILL BE THE MAIN CONCERN...AS THERE WILL LIKELY BE AN AXIS OF HIGHER
PRECIPITATION AMOUNTS ALONG THIS FRONT. LATEST TRENDS IN THE MODELS
IS THAT THE 850MB FRONT IS A LITTLE FARTHER WEST AND THE HEAVIEST
PRECIPITATION LOOKS TO FALL SOMEWHERE EAST OF DULUTH AND WEST OF A
LINE FROM BARAGA TO WATERSMEET. WITH THE AREA THE 850-700MB WAA/FGEN
IS LINING UP...WOULD THINK THAT THE BEST PRECIPITATION WOULD BE OVER
THE FAR WESTERN CWA...BUT STILL EXPECT LIGHTER VALUES OVER THE REST
OF THE WESTERN CWA. THIS MATCHES UP WELL WITH THE 09Z SREF QPF
PROBABILITIES. THERE WILL PROBABLY BE SOME SHOWERS OVER THE
CENTRAL U.P. BUT THE AMOUNTS SHOULD BE LIGHTER THAN SEEN OVER THE
WEST. UNFORTUNATELY...THIS PRECIPITATION WON/T HELP THE ALREADY
SWOLLEN RIVERS AND STREAMS OVER FAR WESTERN UPPER MICHIGAN AND WILL
HEIGHTEN THE AFFECTS IN THE HWO AND INDIVIDUAL RIVER PRODUCTS.
BASED OFF THE THERMAL FIELDS AND BUFKIT SOUNDINGS...IT APPEARS THAT
IT WILL MAINLY BE SNOW OVER THE FAR WESTERN CWA...WITH A RAIN/SNOW
MIX OVER THE WEST-CENTRAL...BEFORE CHANGING TO ALL RAIN EAST OF A
LINE FROM NEGAUNEE TO CRYSTAL FALLS. THERE STILL REMAINS SOME
UNCERTAINTY IN THE P-TYPE TYPE AS THEY HAVE BEEN VARYING IN HOW FAR
WEST THE WARM AIR ALOFT SLIDES. NAM AND OUR REGIONAL WRF-ARW DO HINT
AT A SOME DRYING ALOFT WHICH COULD LIMIT ICE CRYSTAL POTENTIAL OVER
THE WEST...WHICH WILL BE SOMETHING TO WATCH. IF THE PRECIP STAYS AS
SNOW OVER THE WEST HALF OF GOGEBIC AND WESTERN ONTONAGON
COUNTY...THEY COULD SEE SIGNIFICANT LATE SEASON
SNOWFALL...ESPECIALLY ON THE COLDER SURFACES AND HIGHER TERRAIN.
CURRENTLY HAVE BORDERLINE WARNING SNOW AMOUNTS FOR WEDNESDAY NIGHT
INTO THURSDAY MORNING...SO WILL CONTINUE TO MENTION IN THE HWO. IF
CONFIDENCE WAS A LITTLE GREATER ON EXACT LOCATION OF THE HEAVIEST
QPF...AND THERE WEREN/T SEVERAL OTHER FLOOD WARNING/WATCH/ADVISORY
PRODUCTS OUT FOR GOGEBIC COUNTY...COULD HAVE ISSUED A WINTER
STORM WATCH.
THE UPPER TROUGH STARTS THE CUTOFF PROCESS THURSDAY NIGHT INTO
FRIDAY MORNING...WHICH WILL ALLOW THE FLOW ALOFT TO BECOME MORE
SOUTHEASTERLY AND SHIFT THE FRONT WEST. THIS WILL PULL WARMER AIR
INTO THE AREA AND SHOULD LIMIT THE SNOW POTENTIAL. BUT THIS WARMER
AIR MOVING IN ALOFT WILL LEAD COLD AIR TRAPPED NEAR THE SURFACE.
THIS HAS BEEN HINTED AT OVER THE LAST DAY...BUT HAVE CONCERNS THAT
THE GROUND TEMPERATURES WON/T GO BELOW FREEZING. THUS...WILL JUST
HAVE A SLIGHT CHANCE MENTION FOR AREAS WITH RAIN AND TEMPS BELOW 31
DEGREES. WITH THE DIFFERENCES IN THE HANDLING OF THE TROUGH CUTTING
OFF...THERE ARE DIFFERENCES IN THE MOVEMENT OF THE FRONT...SO WILL
GO WITH A BROADER POPS HEADING INTO FRIDAY...BUT THE BEST FOCUS
OVER THE SOUTHWEST HALF.
THE WEEKEND INTO EARLY NEXT WEEK STILL REMAINS UP IN THE AIR DUE TO
THE DIFFERENCES IN THE LOCATION OF THE UPPER LOW. 00Z ECMWF IS
CONSISTENT WITH IT/S PREVIOUS RUN AND IS FARTHEST TO THE NORTH. 12Z
GFS CONTINUES IT/S TREND OF BEING WELL TO THE SOUTH OF THE AREA
/CENTRAL MISSISSIPPI VALLEY/...WHILE THE 12Z GEM HAS IT IN THE
GREAT LAKES. AS WITH YESTERDAY...WILL FOLLOW A GENERAL CONSENSUS
INTO NEXT WEEK AS THE LOCATION OF THE LOW HAS LARGE IMPLICATIONS ON
TEMPERATURES AND PRECIPITATION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 115 AM EDT WED MAY 1 2013
A COLD FRONT WILL PUSH THROUGH ALL THREE TAF SITES OVERNIGHT AND
WEDNESDAY AFTERNOON. THIS WILL BRING RAIN SHOWERS TO ALL THREE TAF
SITES THROUGHOUT THE NIGHT TONIGHT AND INTO THE DAY ON WEDNESDAY.
RADAR SHOWS PRECIPITATION MOVING INTO SOUTHWESTERN UPPER MICHIGAN AS
OF 430Z. LATER IN THE DAY WEDNESDAY...WITH COLD AIR FILTERING IN
BEHIND THE FRONT...THE WESTERN TAF SITES KCMX/KIWD WILL START TO SEE
A CHANGEOVER TO RAIN/SNOW MIX. KIWD WILL GRADUALLY CHANGE TO ALL
SNOW AFTER 00Z 5/2. EXPECT THE SNOW TO BECOME MODERATE AFTER ABOUT
3Z WHEN THE BETTER FORCING ARRIVES ALOFT. AS A RESULT....HAVE IWD
DIMINISHING TO LIFR CONDITIONS TOWARDS THE END OF THE TAF PERIOD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 432 PM EDT TUE APR 30 2013
NO GALES SEEN IN THIS FORECAST PERIOD. WINDS WILL GET UP TO 30 KNOTS
ACROSS THE EASTERN PORTION OF LAKE SUPERIOR EARLY THIS EVENING WITH
TIGHTENING GRAD AHEAD OF COLD FRONT. WINDS THEN STAY GEENRALLY AT OR
BELOW 25 KNOTS FOR THE REST OF THE PERIOD.
&&
.HYDROLOGY...
ISSUED AT 432 PM EDT TUE APR 30 2013
ANOTHER DAY OF WARM TEMPERATURES HAS CONTINUED THE SNOW MELT AND
THE RISING RIVER LEVELS ACROSS THE AREA. FORTUNATELY...RAINFALL
AMOUNTS OVER THE LAST COUPLE OF DAYS HAVE BEEN FAIRLY LIGHT AND HAS
KEPT THE FLOODING CONCERNS TO THE SNOW MELT. THE MAIN SNOW LEFT
OVER THE AREA IS OVER THE HIGHER TERRAIN LOCATIONS OVER THE
WEST...WHERE VALUES ARE IN THE 3-15 INCH RANGE. THE WARM
TEMPERATURES TONIGHT SHOULD CONTINUE THE MELT...BUT IS SHOULD BE
SLOWED AS TEMPERATURES FALL BEHIND A COLD FRONT THAT MOVES
THROUGH TONIGHT. THIS FRONT WILL PRODUCE ISOLATED/SCATTERED SHOWERS
BUT WIDESPREAD MODERATE-HEAVY RAINFALL AMOUNTS ARE NOT EXPECTED.
ATTENTION THEN TURNS TO AN UPPER LEVEL FRONT THAT STALLS OVER FAR
WESTERN UPPER MICHIGAN WEDNESDAY THROUGH THURSDAY. THIS HAS THE
POTENTIAL TO PRODUCE OVER AN INCH OF QPF OVER THE WESTERN THIRD OF
UPPER MICHIGAN THROUGH THURSDAY NIGHT. THE HEAVIEST
AMOUNTS...POTENTIALLY EXCEEDING 1.5 INCHES WILL BE OVER WESTERN
ONTONAGON AND WESTERN GOGEBIC COUNTIES. WITH THE COLDER
TEMPERATURES...THERE IS UNCERTAINTY IN THE THE EXACT PRECIPITATION
TYPE...BUT IT LOOKS LIKE A RAIN/SNOW MIX OVER THE WEST AND MAINLY
SNOW OVER THE FAR WEST. THIS PRECIPITATION WILL NOT HELP MATTERS
OVER THE WESTERN CWA...WHERE MANY RIVERS/STREAMS/CREEKS ARE
EXCEEDING BANKFULL OR FLOODING. THIS PRECIPITATION WILL DEFINITELY
NEED TO BE WATCHED OVER THE NEXT DAY OR TWO TO PIN DOWN AMOUNTS AND
TYPES...WHICH WILL HELP DETERMINE THE TIME THEY WILL INFLUENCE THE
RIVERS. ELSEWHERE...THE TIME LAGGED FLOW INCREASES FROM THE SNOW
MELT WILL LEAD TO CONTINUED RISES OVER THE NORTH CENTRAL
TRIBUTARIES OF THE ESCANABA AND MICHIGAMME RIVERS. THESE AREAS MAY
SEE FLOODING OVER THE COMING DAYS.
IN THE NEAR TERM...THE GREATEST FLOODING THREAT IS FOR THE RIVERS
IN WEST AND CENTRAL UPPER MICHIGAN. SEVERAL RIVER FLOOD
WARNING/WATCH/ADVISORIES ARE ALREADY IN PLACE...ALONG WITH SOME
AERIAL FLOOD ADVISORIES. FOR COMPLETE DETAILS...SEE THE LATEST RIVER
FLOOD WATCHES...WARNINGS AND ADVISORIES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
FLASH FLOOD WATCH THROUGH THIS AFTERNOON FOR MIZ009.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...SRF
AVIATION...MCD
MARINE...VOSS
HYDROLOGY...SRF
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
452 AM CDT WED MAY 1 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 441 AM CDT WED MAY 1 2013
NOT THE TYPICAL MAY FORECAST. CDFNT HAS SETTLED OVER SE WI AND
STRETCHES SWWD INTO CENTRAL AND SRN IA...AND WILL REMAIN QUASI-
STNRY OVER THESE AREAS THRU THE NEXT 24 HRS. SIGNIFICANT CAA IS IN
PROGRESS AS EVIDENCED BY TEMPS IN THE LOW 30S IN NRN AND WRN MN
WHILE THE ERN AND SRN MN INTO WRN WI IS IN THE 40S AND 50S. A
POTENT UPR LEVEL TROF WILL STALL OUT OVER THE NRN PLAINS AND UPR
MISS RIVER VALLEY...DIGGING FURTHER S AND SLIGHTLY PIVOTING TO
ENHANCE LIFT AND ALSO ALLOW A PROLONGED STREAM OF SRN MOISTURE TO
ADVECT WELL N INTO THIS REGION...DEEPENING THE MOISTURE COLUMN.
PWATS SURGE TO WELL OVER AN INCH THRU TNGT. IN ADDITION...MOST
RAIN/SNOW LAYER THRESHOLDS BECOME MUCH SHORTER PER BUFKIT PROFILES
BY LATE AFTN...INDICATING THAT THE PRECIP FALLING WILL TAKE THE
FORM OF SNOW RATHER THAN RAIN...HIGHLY UNUSUAL FOR THE MONTH OF
MAY. IN FACT...LOCAL HOPWRF GUIDANCE SHOWS SEVERAL SWATHS OF 1-3
IN/HR SNOW BANDS INTO CENTRAL-ERN MN BY MIDDAY WHICH MAKES SENSE
GIVEN THAT SPC SREF AND RAP GUIDANCE INDICATES VERY STRONG H7
FGEN. THE MAIN CONCERN IS THAT DEWPOINTS ARE STILL IN THE LOWER
20S WHERE TEMPS HAVE DROPPED TO THE FREEZING MARK. SHOULD
WETBULBING EFFECTS OCCUR...DROPPING THE TEMP FASTER THAN
ADVERTISED AND KEEPING IT THERE...ACCUMULATIONS COULD OCCUR
QUICKER AND EARLIER THAN ADVERTISED DESPITE THE WARM ROAD SFC
TEMPS OF THE PAST SEVERAL DAYS. COULD SEE 1-3 INCHES OF SOLID
ACCUMULATION THIS AFTN ONCE THE RAIN CHANGES OVER TO SNOW AND
INTENSITY IS MOD-HVY. WILL STILL LOOK FOR TEMPS TO FALL THRU THE
DAY TDA AND TNGT AS THE UPR TROF CONTINUES TO DIG OVER THE DAKOTAS
AND SFC WINDS SHIFT TO NW-N. GOING INTO TNGT...AT LEAST ONE HVY
BAND OF SNOW IS EXPECTED TO DEVELOP FROM NRN IA INTO SRN AND SE
MN...WITH STRONG FGEN OVER THIS SAME AREA LASTING THROUGH
DAYBREAK ON THU. BUFKIT SOUNDINGS STILL SHOW SOLID SUBFREEZING
SOUNDINGS WITH MOD-HVY SNOW ALONG A MANKATO-MINNEAPOLIS-BARRON
LINE WHERE 6-9 INCHES OF ACCUMULATION IS CERTAINLY WITHIN REASON
IN THIS FORECAST. GOING FURTHER E AND W...ACCUMULATIONS DROP OFF
IN A RATHER TIGHT GRADIENT...SUCH THAT NWRN PORTIONS OF THE MPX
CWFA MAY NOT EVEN SEE 1 INCH. THAT SAID...WPC GUIDANCE STILL PINS
A 8-10 INCH SWATH OF SNOWFALL OVER S-CENTRAL MN INTO E-CENTRAL MN
AND W-CENTRAL WI...AND WITH QPF NEARING AN INCH...EVEN SNOWFALL
RATIOS IN THE 4 OR 5 TO 1 AREA PRODUCE A STORM TOTAL OF 4-7
INCHES THRU TNGT WITH SLIGHT ADDITIONS FOR THU. NORMALLY THE
WARMER GROUND WOULD BE ABLE TO MELT THE SNOW AS IT FALLS...AND THE
WET NATURE OF THE SNOW WOULD ALSO HINDER ACCUMULATIONS. HOWEVER...
THE STRONG FGEN WITH HIGH SNOWFALL RATES FOR SEEM TO COMBAT THAT
THINKING IN THIS CASE...LEANING MORE TWD AGREEMENT WITH THE WPC
OUTPUT.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 441 AM CDT WED MAY 1 2013
MODEL AGREEMENT THIS PERIOD REMAINS HIGH THROUGH FRIDAY...BUT
QUICKLY DISAPPEARS FROM FRIDAY NIGHT ONWARDS WITH HOW EACH MODEL
HANDLES THE PROGRESSION OF WHAT WILL BE A CUT OFF LOW THAT SETS UP
NEAR KANSAS CITY BY SATURDAY MORNING. ABOUT THE ONLY THING THERE IS
AGREEMENT ON BEYOND FRIDAY IS THAT HEIGHTS WILL SLOWLY MODIFY FROM
THE WEEKEND INTO NEXT WEEK...WHICH WILL ALLOW HIGHS TO WORK BACK
CLOSER TO EARLY MAY NORMALS.
FOR THURSDAY...FGEN INDUCED BAND OF HEAVY PRECIPITATION WILL
SLOWLY MOVE INTO WRN WI THU MORNING...AND LOOKS TO SPEND MOST OF
THE DAY CONFINED TO AREAS EAST OF AN ALBERT LEA TO RUSH CITY LINE.
GIVEN EXPECTED PERSISTENT PRECIPITATION AND CLOUD COVER...NUDGED
HIGHS DOWN INTO THE MID 30S FOR THURSDAY ACROSS ERN AREAS...WHICH
IS ABOUT 30 DEGREES BELOW NORMAL. OF COURSE THE OTHER IMPACT OF
THE COOLER TEMPS FOR THURSDAY IS THIS MAY ALLOW SNOW TO BE THE
PREDOMINATE P-TYPE FROM WED NIGHT RIGHT THROUGH THE DAY ON
THURSDAY. THE ONLY THING THAT HAS REALLY CHANGED IS A WESTWARD
SHIFT IN THE WARM NOSE BETWEEN H8 AND H7. THE GFS IN PARTICULAR
BRINGS THIS OUT TO ABOUT AN EAU CLAIRE TO LADYSMITH LINE...WITH A
PRETTY SHARP GRADIENT IN POTENTIAL SNOW TOTALS RESULTING ACROSS
THE ERN CWA...WITH VERY LITTLE ACCUMS AT AUGUSTA...WHILE A
MENOMONIE WOULD HAVE THE POTENTIAL FOR AROUND 8 INCHES. GIVEN THE
COOLER TEMPERATURES FOR THURSDAY AND THE POTENTIAL FOR CONTINUED
SNOW ACCUMS THROUGH THE DAY...WE DECIDED TO CARRY WINTER HEADLINES
THROUGH 00Z /7 PM THU/. AS WITH THE SHORT TERM...SNOW TOTALS ARE
TRICKY HERE AS GIVEN THE RATHER HIGH QPF NUMBERS...EVEN
POTENTIALLY UNREALISTIC SNOW RATIOS OF 4-6:1 STILL YIELD SNOWFALL
AMOUNTS THAT ARE OFF INTO UNCHARTED TERRITORY FOR MAY SNOWFALLS IN
THIS AREA. CURRENT GRIDS HAVE ABOUT A 100 MILE WIDE SWATH OF 6-9
INCHES OF SNOW THAT IS CENTERED ALONG A BLUE EARTH /CITY/...TO
HASTINGS...TO CUMBERLAND...WI LINE.
THOUGH CERTAINLY THE WARM SOILS/PAVEMENT TEMPS FROM THE RECENT
WARM SPELL WILL HAVE THE POTENTIAL TO LIMIT ACCUMULATIONS...
EXPECTED SNOWFALL RATES FROM TONIGHT INTO AT LEAST THURSDAY
MORNING IN THE 1-2 INCH PLUS RANGE WILL BE MORE THAN ENOUGH TO
ACCUMULATE ON ANY SURFACE WHILE THOSE TYPES OF RATES ARE BEING
OBSERVED. THERE IS CERTAINLY POTENTIAL FOR SNOWFALL AMOUNTS TO GO
EITHER WAY /HIGHER OR LOWER/ WITH THIS SYSTEM...BUT IF THE CURRENT
FORECAST DOES PAN OUT...THIS STORM WILL CERTAINLY BE RE- WRITING
THE RECORD BOOKS FOR MAY SNOWFALL ACROSS SOUTHERN MN AND WRN WI.
FOR THURSDAY NIGHT INTO FRIDAY...THE FOCUS FOR THE HEAVY
PRECIPITATION SHIFTS EAST FROM ERN IA INTO CENTRAL WI AS LLJ
SLOWLY SHIFTS EAST. AS RESULT...HAVE CUT BACK ON POPS IN THIS
PERIOD... ESPECIALLY ACROSS MN...WITH MUCH OF THE AREA LIKELY
SEEING A BIT OF A REPRIEVE FROM THE PRECIPITATION. IN
ADDITION...WRN MN WILL LIKELY SEE SOME FILTERED SUNSHINE...WHICH
WILL ALLOW WRN AREAS TO WARM BACK TOWARD THE 50S.
FOR FRIDAY NIGHT...MODEL DISAGREEMENTS START TO INCREASE
DRAMATICALLY WITH HANDLING OF A SURGE OF WAA ADVECTIVE PRECIP THAT
WILL BE COMING IN FROM THE SE AS A STRONG VORT MAX ROTATES
AROUND THE MAIN UPPER LOW OVER NRN MO /OFF THE NAM ANYWAYS/. THE
NAM IS THE MIDDLE MEMBER WITH THIS FEATURE...BRINGING ANOTHER
SHIELD OF HEAVY PRECIPITATION ACROSS THE MPX CWA FRIDAY NIGHT INTO
SATURDAY MORNING. THE GFS HAS A SIMILAR FEATURE...BUT KEEPS THE
BRUNT OF THE PRECIPITATION DOWN ACROSS IA. THE ECMWF HAS A
COMPLETELY DIFFERENT IDEA WITH HOW THIS UPPER LOW WILL EVOLVE.
WHERE THE GFS ON SAT HAS THE UPPER LOW OVER NRN ARK...THE NAM OVER
NRN MO...THE 01.00 ECMWF HAS THE SAME...MUCH SHALLOWER LOW UP NEAR
THE MN/DAKOTAS BORDER! GIVEN THE DISAGREEMENTS...HELD POPS TO NO
HIGHER THAN LIKELY ON SATURDAY AS IT COULD RANGE FROM ANYWHERE
BETWEEN A WASHOUT TO JUST COOL AND CLOUDY. AT THE VERY LEAST...AT
LEAST THIS POTENTIAL WAVE OF PRECIPITATION LOOKS TO BE WARM ENOUGH
TO KEEP EVERYTHING LIQUID.
GOING INTO NEXT WORK WEEK...BOTH THE GFS AND THE ECMWF SHOW
ANOTHER OMEGA BLOCK DEVELOPING...ONLY THIS TIME ACROSS THE WRN
US. THE ECMWF IS THE FARTHEST WEST WITH THIS FEATURE...WHICH
ALLOWS IT TO SEND ANOTHER STRONG SHORTWAVE AND COLD FRONT THROUGH
THE MPX AREA MONDAY NIGHT INTO TUESDAY. THE GFS HAS THE BLOCK
FARTHER EAST AND WOULD KEEP THE REGION DRY. AT THIS POINT...KEPT
THE MAINLY CHANCE POPS THAT WERE IN PLACE DURING THIS TIME FRAME.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1058 PM CDT TUE APR 30 2013
RAIN CHANCES WILL BE ON THE INCREASE TONIGHT...WITH CIGS EXPECTED
TO LOWER TO MVFR CATEGORY OVERNIGHT AND EARLY WEDNESDAY MORNING AT
KMSP/KRNH/KEAU. CONVERSELY...CONDITIONS AT KAXN AND KSTC ARE
EXPECTED TO REMAIN VFR THROUGH THE PERIOD/EVENT. THERE/S STILL
UNCERTAINTY AS TO WHEN THE CHANGEOVER TO SNOW WILL BE...BUT LATE
MORNING AND EARLY AFTERNOON IN MN...AND EARLY EVE IN WI...SEEM
LIKE REASONABLE TIME FRAMES. MVFR CIGS/VSBYS WITH OCCASIONAL IFR
VSBYS IN -SN ARE THEN EXPECTED INTO THURSDAY. WINDS OF 330-360
DEGREES WILL PREVAIL THROUGH THE PERIOD...WITH GUSTS UP TO 20 KTS
DEVELOPING WEDNESDAY.
KMSP...
PRETTY MUCH STATUS QUO IN THE TAF. STILL EXPECTING TO MIX SOME
FLAKES IN WITH THE RAIN DURING THE DAY ON WEDNESDAY. THERE IS
STILL A FAIR AMOUNT OF UNCERTAINTY IN HOW FAST WE COOL FOR THE
TRANSITION TO SNOW. AT ANY RATE...EVEN IF SNOW BEGINS IN THE
MORNING...LITTLE TO NO ACCUMULATION IS EXPECTED GIVEN THE WARM
GROUND AND RELATIVELY LIGHT INTENSITY OF PRECIPITATION. ONCE THE
SNOW BEGINS...VSBY REDUCTIONS TO IFR WILL BE POSSIBLE. WINDS FROM
320-350 DEGREES AOB 11 KTS THROUGH WEDNESDAY...THEN GUSTS TO 20
KTS DEVELOPING WEDNESDAY EVE.
/OUTLOOK FOR KMSP/
THU...MVFR CIGS/VSBYS POSSIBLE WITH CHC -RA/-SN. NW WINDS 15 KT.
FRI...MVFR CIGS/VSBYS POSSIBLE WITH CHC -RA/-SN. NE WINDS 10-15
KT.
SAT...MVFR CIGS/VSBYS POSSIBLE WITH CHC -RA. ENE WINDS 5 KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WINTER STORM WARNING FROM 3 PM THIS AFTERNOON TO 7 PM CDT
THURSDAY FOR MNZ053-060>063-067>070-074>078-082>085-091>093.
WINTER WEATHER ADVISORY FROM 3 PM THIS AFTERNOON TO 7 PM CDT
THURSDAY FOR MNZ044-045-051-052-058-059-065-066-073.
WI...WINTER STORM WARNING FROM 3 PM THIS AFTERNOON TO 7 PM CDT
THURSDAY FOR WIZ014>016-023>025.
WINTER WEATHER ADVISORY FROM 3 PM THIS AFTERNOON TO 7 PM CDT
THURSDAY FOR WIZ026>028.
&&
$$
SHORT TERM...JPC
LONG TERM...MPG
AVIATION...LS
AREA FORECAST DISCUSSION
NWS MIAMI FL
943 AM EDT WED MAY 1 2013
.UPDATE...
MASSIVE CLOUD FIELD CURRENTLY OVER THE EASTERN GOFMEX ASSOCIATED
WITH LARGE CONVECTIVE COMPLEX ROTATING BENEATH CUT-OFF LOW WHICH
IS OVER THE SOUTH CENTRAL GULF STATES. THIS LINE OF CONVECTION
HAS BEEN PRODUCING A TREMENDOUS AMOUNT OF LIGHTNING WITH NEARLY 800
STRIKES IN THE PAST 15 MINUTES. THE CONVECTIVE FIELD IS MOVING
EAST BUT THE QUESTION IS IF IT WILL HOLD TOGETHER BEFORE REACHING
THE LOCAL GULF WATERS AND HOW MUCH EFFECT THE DEBRIS CLOUD FIELD
WILL HAVE ON DIURNAL HEATING OVER THE MAINLAND. FORECAST SOUNDINGS
ALONG WITH THE 12Z MFL SOUNDING WOULD SUGGEST THE POSSIBILITY OF
AT LEAST SOME STRONG STORMS ESPECIALLY ALONG THE EAST COAST WITH
THE LOW LEVEL SOUTHEAST FLOW. HOWEVER, IT IS ALSO POSSIBLE THAT
HEATING WILL BE HELD OFF ENOUGH TO NOT ALLOW SIGNIFICANT UPDRAFTS
TO OCCUR. THE HRRR IS SHOWING SOME WEAKENING AS THE SYSTEM
APPROACHES THE GULF COAST BUT WITH ADDITIONAL DEVELOPMENT OVER THE
MAINLAND AS SOME HEATING TAKES PLACE WITH MOVEMENT TOWARDS THE
EAST COAST. THE 12Z MFL SOUNDING DOES INDICATE A STORM MOTION TO
THE EAST AT AROUND 5 KNOTS. ALL OF THIS SAID, CURRENT THINKING IS
TO ADD MENTION OF POSSIBLE STRONG STORMS FOR THIS AFTERNOON AND
EXTEND HIGHER POPS BACK TO THE WEST COAST TO ACCOUNT FOR THE
APPROACHING CONVECTION.
KOB
&&
.PREV DISCUSSION... /ISSUED 807 AM EDT WED MAY 1 2013/
AVIATION...
TODAY WILL LIKELY BE A REPLAY OF THE LAST COUPLE OF DAYS, ONCE AGAIN.
EXPECT SOME CONVECTIVE SHOWER ACTIVITY IN THE MORNING, THEN THUNDERSTORMS
TO DEVELOP IN THE LATE MORNING TO EARLY AFTERNOON. THESE CAN LEAD TO
MVFR AND IFR CONDITIONS AT TIMES. HAVE ADDED PROB30 GROUPS TO ALL EAST
COAST TAF SITES FOR THE AFTERNOON HOURS. THIS TIME THERE IS A BETTER
CHANCE TSTMS COULD LINGER INTO THE EVENING HOURS SO LEFT VCTS IN THE
FORECAST FOR THE EVENING HOURS ALSO. WINDS WILL BE LIGHT AND VARIABLE
THIS MORNING AND PICK UP OUT OF THE SOUTHEAST MID TO LATE MORNING AROUND
10 KTS WITH A CHANCE OF A SOUTHWEST SEA BREEZE OF 5 T0 10 KNOTS AT APF
IN THE MID TO LATE AFTERNOON FOR A COUPLE OF HOURS.
PREV DISCUSSION... /ISSUED 416 AM EDT WED MAY 1 2013/
.WET WEATHER CONTINUES OVER SOUTH FLORIDA THROUGH EARLY THIS WEEKEND...
.SOME STRONG STORMS POSSIBLE TODAY AND AGAIN THURSDAY OVER SOUTH FLORIDA...
SHORT TERM...
LOW PRESSURE OVER THE WESTERN ATLANTIC WATERS WILL MOVE EAST TODAY
AS A MID TO UPPER LEVEL LOW OVER THE SOUTHERN GULF COAST STATES
MOVES SOUTHEAST INTO THE NORTHERN GULF OF MEXICO. THIS WILL ALLOW
FOR A TROUGH OF LOW PRESSURE OVER CENTRAL FLORIDA TO MOVE SOUTH INTO
THE LAKE OKEECHOBEE REGION TODAY KEEPING THE STEERING FLOW IN A
SOUTH TO SOUTHWEST DIRECTION OVER SOUTH FLORIDA. SO THE DEEP
TROPICAL MOISTURE WILL CONTINUE TO WORK INTO THE AREA FROM THE SOUTH
ALLOWING FOR SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS. THE
STORMS WILL ALSO BE SLOW MOVERS TODAY LEADING TO HEAVY RAINFALL OVER
SOUTH FLORIDA. SO WILL CONTINUE TO MENTION THE HEAVY RAINFALL IN THE
ZONES FOR TODAY OVER SOUTH FLORIDA.
THE TROUGH OF LOW PRESSURE WILL REMAIN NEARLY STATIONARY TONIGHT
INTO THURSDAY...AS THE MID TO UPPER LEVEL LOW MOVES SLOWLY
SOUTHEAST INTO THE EASTERN GULF OF MEXICO. A SURFACE LOW WILL
ALSO DEVELOP IN THE EASTERN GULF OF MEXICO ON THURSDAY WHICH WILL
HELP KEEP THE SOUTH TO SOUTHWEST STEERING FLOW OVER SOUTH FLORIDA
ALONG WITH THE DEEP TROPICAL MOISTURE. SO WILL CONTINUE THE
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS OVER SOUTH FLORIDA
FOR THURSDAY ALONG WITH THE HEAVY RAINFALL WORDING.
THE 500 MB TEMPS WILL ALSO COOL OFF A BIT FROM AROUND -10C THIS
MORNING TO -12C TO -13C ON THURSDAY. THIS WILL ALLOW FOR SOME STRONG
STORMS OVER SOUTH FLORIDA TODAY...AND STRONG TO EVEN SEVERE STORMS
(WITH POTENTIAL FOR MORE THAN THE ORDINARY DEPENDING HOW MUCH
SURFACE HEATING WE END UP GETTING) ON THURSDAY OVER SOUTH FLORIDA.
ALTHOUGH THE PRIMARY THREAT FROM THE STORMS WILL CONTINUE TO BE
FLOODING POTENTIAL...SECONDARY THREATS FROM THE STORMS WILL BE GUSTY
WINDS...HAIL...AND FREQUENT LIGHTING STRIKES.
THE LOW OVER THE EASTERN GULF OF MEXICO WILL SLOWLY MOVE EAST ON
FRIDAY TOWARDS SOUTH FLORIDA...AS THE TROUGH OF LOW PRESSURE
REMAINS OVER SOUTH FLORIDA. THIS WILL CONTINUE TO KEEP THE DEEP
TROPICAL MOISTURE IN PLACE OVER SOUTH FLORIDA ON FRIDAY. SO WILL
CONTINUE THE SCATTERED TO NUMEROUS POPS OVER THE AREA FOR FRIDAY
ALONG WITH THE HEAVY RAINFALL WORDING.
LONG TERM...
THE LOW WILL MOVE EAST OVER SOUTH FLORIDA ON SATURDAY BEFORE
MOVING INTO THE WESTERN ATLANTIC WATERS ON SUNDAY. THIS WILL KEEP
THE AREA IN THE DEEP TROPICAL MOISTURE ON SATURDAY...BEFORE
ALLOWING FOR SOME DRIER AIR TO WORK INTO THE AREA FROM THE WEST ON
SUNDAY. THEREFORE...THE POPS ON SATURDAY WILL BE IN THE SCATTERED
RANGE OVER SOUTH FLORIDA WHILE ON SUNDAY THE POPS WILL BE IN SLIGHT
CHANCE TO LOW END CHANCE.
FOR EARLY NEXT WEEK...THE DRIER WEATHER WILL CONTINUE TO WORK INTO
THE AREA FROM THE NORTH AND WEST. SO THE WEATHER SHOULD BE DRY
OVER SOUTH FLORIDA FOR EARLY NEXT WEEK...AND WILL REMOVE THE SHOWER
AND THUNDERSTORM WORDING OVER SOUTH FLORIDA FOR EARLY NEXT WEEK.
HOWEVER...THERE REMAINS QUITE A BIT OF UNCERTAINTY AMONG THE MODELS
AND THIS OUTLOOK COULD CHANGE WITH THE WET PERIOD EITHER ENDING
EARLIER THAN SUNDAY OR LATER THAN ANTICIPATED INTO EARLY NEXT WEEK.
MARINE...
THE WINDS OVER SOUTH FLORIDA TODAY INTO THURSDAY WILL BE FROM THE
EAST TO SOUTHEAST AT 10 KNOTS OR LESS...BEFORE INCREASING TO
BREEZY CONDITIONS BY EARLY THIS WEEKEND FROM THE SOUTHERLY
DIRECTION. AT THE SAME TIME...A NORTHEAST SWELL OF 2 TO 3 FEET
WILL ALSO CONTINUE TO AFFECT THE PALM BEACH WATERS OF SOUTH
FLORIDA. THIS WILL ALLOW FOR THE SEAS TO REMAIN BELOW 6 FEET IN
THE ATLANTIC WATERS TODAY INTO THURSDAY...BEFORE INCREASING TO 7
FEET BY FRIDAY IN THE PALM BEACH WATERS. FOR THE GULF SIDE...THE
SEAS WILL REMAIN BELOW 6 FEET TODAY INTO EARLY THIS WEEKEND.
FIRE WEATHER...
THE RELATIVE HUMIDITIES WILL REMAIN ABOVE THE 35 PERCENT CRITICAL
VALUE EACH DAY OVER SOUTH FLORIDA THROUGH END OF THIS WEEK...DUE
TO THE TROPICAL MOISTURE REMAINING OVER THE AREA. SO NO PROBLEMS
ARE EXPECTED WITH THE FIRE WEATHER OVER SOUTH FLORIDA.
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DULUTH MN
1055 AM CDT WED MAY 1 2013
.UPDATE...
A NARROW BAND OF RAIN AND SNOW EXTENDED NORTHEAST ACROSS SOUTHERN
PINE COUNTY ACROSS BURNETT...WASHBURN...DOUGLAS AND BAYFIELD
COUNTIES. KRZN HAS RECENTLY WENT TO SNOW...AND A SPOTTER IN
HERBSTER WAS ALSO REPORTING SNOW. THE RAP WAS SHOWING LOWER
WETBULB ZERO VALUES THIS MORNING...BUT HAD THEM INCREASING AGAIN
THIS AFTERNOON. WE THINK THE RAP MAY BE OVERDOING THE INCREASE
THIS AFTERNOON SOME AS THEY RAISE SURFACE TEMPS BACK INTO THE
FORTIES WHICH LOOKS UNLIKELY. SNOWFALL TODAY SHOULD BE LIMITED TO
LESS THAN AN INCH.
THE LATEST NAM STILL SHOWS IMPRESSIVE FGEN TONIGHT...AND WE EXPECT
HEAVY SNOW TO DEVELOP. THE CURRENT HEADLINES BASED ON THE NAM
STILL LOOK GOOD ACROSS WISCONSIN...BUT IT`S LOOKING MORE LIKELY
WE`LL NEED TO UPGRADE IRON COUNTY TO A WARNING. PRICE IS STILL
QUESTIONABLE...BUT THE NORTHERN HALF OF THE COUNTY SHOULD RECEIVE
SOME HEAVY SNOW SO WE MAY HAVE TO UPGRADE THEM AS WELL. WE`LL LOOK
OVER THE LATEST MODELS AND WAIT UNTIL THE AFTERNOON BEFORE MAKING
ANY CHANGES.
WE ALSO MAY HAVE TO INCREASE SNOW TOTALS ACROSS PORTIONS OF
NORTHWEST WISCONSIN GIVEN THE LATEST NAM. WE`LL WAIT FOR THE
GFS/ECMWF BEFORE FINALIZING SNOW TOTALS THIS AFTERNOON. WE
WOULDN`T BE SURPRISED IF SOME THUNDERSNOW DEVELOPS OVERNIGHT...AS
CROSS SECTIONS SHOW IMPRESSIVE FGEN WITH SOME NEGATIVE EPV AND
EVEN LOW CAPE FEEDING INTO NORTHWEST WISCONSIN. CONVECTIVE
SNOWFALL CAN PRODUCE HEAVY SNOW RATES...WITH 2 TO 3 INCHES PER
HOUR POSSIBLE.
&&
.PREV DISCUSSION... /ISSUED 657 AM CDT WED MAY 1 2013/
AVIATION...12Z TAF ISSUANCE...
FRONT HAS STALLED FROM IOWA INTO CENTRAL WISCONSIN THIS
MORNING..WITH FOCUS FOR PRECIPITATION REMAINING LOCKED IN THE
CORRIDOR JUST ON THE COOL SIDE OF THE FRONT ACROSS NW
WISCONSIN..INCLUDING KHYR TAF SITE THROUGH TONIGHT. RAIN IS
ALREADY AFFECTING KHYR WITH VFR CEILING AS OF 11Z THIS MORNING.
HOWEVER..CEILINGS/VISIBILITIES ARE EXPECTED TO GRADUALLY LOWER
THROUGH THE DAY..WITH RAIN MIXING WITH AND EVENTUALLY CHANGING TO
SNOW THIS EVENING AND OVERNIGHT WITH IFR CIGS/VSBYS DEVELOPING.
THERE IS EXPECTED TO BE A VERY SHARP GRADIENT/CUT OFF IN PRECIP ON
THE NORTHWEST SIDE OF THIS SYSTEM..AND THUS KDLH/KBRD/KINL/KHIB
HAVE NO PRECIP MENTIONED THRU THE PERIOD WITH VFR CEILINGS AND
WINDS GRADUALLY VEERING FROM WNW TO N OR NNE BY TONIGHT.
PREV DISCUSSION... /ISSUED 430 AM CDT WED MAY 1 2013/
SHORT TERM...TODAY THROUGH THURSDAY.
THINGS ARE COMING TOGETHER FOR A FAIRLY MAJOR EARLY MAY SNOW STORM
ACROSS THE NORTHLAND. THE MODELS CONTINUE TO INDICATE THE
POTENTIAL FOR VERY HEAVY SNOW ACCUMULATION TONIGHT AND THURSDAY
ACROSS NORTHWESTERN WISCONSIN. THE MODELS DIFFER TO SOME EXTENT ON
THE SNOW POTENTIAL ON THE MINNESOTA SIDE...AND ALSO IN THE HURLEY
AND PARK FALLS AREAS. HAVE UPGRADED THE WATCH FOR MOST OF
NORTHWESTERN WISCONSIN TO A WARNING...BUT WILL KEEP IRON AND PRICE
COUNTIES IN A WATCH FOR NOW. ON THE MINNESOTA SIDE...HAVE ISSUED A
WINTER WEATHER ADVISORY FOR SNOW FROM PINE COUNTY...TOWARD DULUTH
AND INTO THE ARROWHEAD.
THE MAJORITY OF THE MODEL SOLUTIONS PAINT ANYWHERE FROM 6 TO 12
INCHES OF TOTAL SNOW ACCUMULATION ACROSS MUCH OF NORTHWESTERN
WISCONSIN. THE SREF PLUMES SHOW A WIDE SPREAD OF POSSIBLE TOTAL
SNOWFALL...WITH AMOUNTS RANGING FROM LESS THAN AN INCH TO AS MUCH
AS 19 INCHES. THE MAJORITY OF THE VALUES LIE SOMEWHERE NEAR THE
MEAN...WHICH IS AROUND 11 INCHES AT KHYR. THE MEAN AT SIREN WI IS
CLOSE TO 8 INCHES...WITH A LITTLE OVER 10 INCHES AT ASHLAND.
FURTHER WEST...THERE IS A LOT MORE QUESTION ACROSS THE MN SIDE.
THE MEAN FROM THE PLUMES FOR DULUTH IS BETWEEN 3 AND 4 INCHES BUT
WITH A HUGE MODEL SPREAD. WE ARE FAIRLY CONFIDENT THAT A BAND OF
VERY HEAVY SNOW WILL SET UP ACROSS MUCH OF NW WI...BUT AMOUNTS
FURTHER WEST ARE STILL TRICKY DUE TO THE SHARP GRADIENT IN
SNOWFALL EXPECTED. FOR EXAMPLE...THE NAM AND THE GFS BRING VERY
LITTLE SNOW ACCUMULATION TO DULUTH...WHILE THE ECMWF BRINGS A GOOD
4 TO 6 INCHES.
FOR TODAY...WILL START WITH LIGHT RAIN ACROSS THE REGION...AS IT
SPREADS QUICKLY IN FROM THE SOUTHWEST. TEMPS WILL START OUT IN THE
30S NORTHWEST AND 50S SOUTHEAST. TEMPS WILL BEGIN TO FALL DURING
THE DAY...RESULTING IN A MIXING WITH SNOW. THE PRECIPITATION
SHOULD LARGELY BECOME ALL SNOW TONIGHT...WITH SNOWFALL RATES OF
MORE THAN AN INCH AN HOUR AT TIMES...ESPECIALLY IN THE WARNING
AREA.
THE SNOW WILL THEN BEGIN TO MIX WITH RAIN AS IT DIMINISHES BY
THURSDAY AFTERNOON. IN ALL WE THINK 6 TO 12 IN NW WI...AND 2 TO 4
OR 3 TO 6 IN ADJACENT AREAS OF NE MN.
LONG TERM...THURSDAY NIGHT THROUGH TUESDAY...
QUITE A BIT OF UNCERTAINTY THROUGHOUT THE LONG TERM PERIODS..
BEGINNING WITH HANDLING OF UPPER LOW THAT WILL DEVELOP OVER THE
CENTRAL U.S. OVER THE NEXT 36 HOURS. THERE IS STILL FAIRLY WIDE
RANGING DIVERGENCE IN THE MODEL GUIDANCE..WITH SEVERAL RUNS TAKING
THE LOW MORE EAST INTO THE OHIO VALLEY/LOWER GRT LAKES..WITH THE
ECMWF STILL BEING THE LONE MODEL OUT IN LIFTING THE LOW NWD ACROSS
MN FRIDAY-SATURDAY. IF THE ECM SOLUTION COMES TO BEAR..WE WILL
LIKELY HAVE A LONGER DURATION RAIN/SNOW EVENT OVER MUCH OF THE CWA
TO DEAL WITH EVEN AFTER THE HEAVY SNOWS OVER NW WISCONSIN IN THE
IMMEDIATE SHORT TERM.
SIMILAR STORY FOR HANDLING OF THE FLOW PATTERN AND FORCING FOR THE
SUNDAY-TUESDAY TIME FRAME..WITH EVEN MORE SPREAD IN THE VARIOUS
DETERMINISTIC AND ENSEMBLE SOLUTIONS. SOME HAVE A VERY BLOCKED/CUT
OFF PATTERN, WHILE OTHERS TRANSITION TO A MORE WNW PROGRESSIVE NRN
STREAM PATTERN BY TUESDAY.
NEEDLESS TO SAY..CONFIDENCE IN ANY DETAILS WHATSOEVER IS VERY LOW
RIGHT NOW FOR THE ENTIRE DAY 2-7 TIME PERIOD. GIVEN THIS..WE HAVE
OPTED TO KEEP A MENTION OF AT LEAST SOME CHANCES FOR PRECIP IN MOST
PERIODS..ALONG WITH TEMPS AT OR SLIGHTLY BELOW SEASONAL NORMS.
HYDROLOGY...
RIVERS LEVELS CONTINUE TO RISE..ALTHOUGH AT A SLOWER RATE THAN THE
PAST FEW DAYS ACROSS THE SOUTHERN PARTS OF THE CWA AS MOST SNOW HAS
MELTED AND IN MOVING WITHIN THE DRAINAGE SYSTEM. FLOOD WARNINGS ARE
IN EFFECT ALONG THE MISSISSIPPI RIVER AT AITKIN AND FORT RIPLEY AND
ALONG THE ST. LOUIS RIVER AT SCANLON FOR MINOR FLOODING. THERE ARE
ALSO AREAL FLOOD ADVISORIES ACROSS PARTS OF THE NORTHLAND DUE TO
SOME REPORTS OF FLOODING...INCLUDING ALONG AND OVER SOME ROADWAYS.
OF PARTICULAR CONCERN THE NEXT 48-60 HOURS IS VERY RAPID MELT/RUNOFF
AND AREAL/RIVER FLOODING ACROSS THE GOGEBIC RANGE AREA OF NORTHWEST
WISCONSIN. THE BAD RIVER CONTINUES TO RISE AS WELL...AND WE MAY BE
UPGRADING TO WARNING THERE AS WELL BUT ARE WAITING FOR SOME MORE
INFORMATION BEFORE DOING SO.
PRECIPITATION WILL OVERSPREAD NW WISCONSIN AND FAR EASTERN MINNESOTA
TODAY...AND IT WILL LIKELY CONTINUE THROUGH AT LEAST THURSDAY..
INITIALLY IN THE FORM OF RAIN..BUT TRANSITIONING TO SNOW LATE THIS
AFTERNOON AND TONIGHT. MUCH OF NORTHWEST WISCONSIN WILL LIKELY GET
AT LEAST A HALF INCH OF QPF THROUGH THURSDAY...WITH SOME
INDICATIONS OF OVER AN INCH. ALTHOUGH HEAVY WET SNOW IS EXPECTED
TONIGHT INTO THURSDAY...THIS PRECIPITATION WILL EVENTUALLY IMPACT
THE RIVER AND STREAMS. THE PRECIPITATION IS NOT EXPECTED TO HAVE
LARGE IMPACTS IMMEDIATELY TO FLOODING CONCERNS...BUT IT WILL
LIKELY RESULT IN ADDITIONAL RISES ALONG SOME STREAMS AND RIVERS
LATER THIS WEEK INTO THE WEEKEND.
&&
.POINT TEMPS/POPS...
DLH 45 31 43 32 / 50 70 70 20
INL 40 27 43 28 / 10 10 10 10
BRD 44 28 46 32 / 20 10 10 10
HYR 44 31 37 30 / 90 100 90 50
ASX 46 30 35 30 / 90 100 100 50
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 7 PM CDT
THURSDAY FOR MNZ012-020-021-037-038.
WI...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 PM CDT THURSDAY
FOR WIZ001>003-006>008.
WINTER STORM WATCH FROM 7 PM CDT THIS EVENING THROUGH THURSDAY
EVENING FOR WIZ004-009.
LS...NONE.
&&
$$
SHORT TERM...MELDE
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
712 AM CDT WED MAY 1 2013
.UPDATE...
ISSUED AT 643 AM CDT WED MAY 1 2013
UPDATED TO INCLUDE 12Z AVIATION DISCUSSION BELOW.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 441 AM CDT WED MAY 1 2013
NOT THE TYPICAL MAY FORECAST. CDFNT HAS SETTLED OVER SE WI AND
STRETCHES SWWD INTO CENTRAL AND SRN IA...AND WILL REMAIN QUASI-
STNRY OVER THESE AREAS THRU THE NEXT 24 HRS. SIGNIFICANT CAA IS IN
PROGRESS AS EVIDENCED BY TEMPS IN THE LOW 30S IN NRN AND WRN MN
WHILE THE ERN AND SRN MN INTO WRN WI IS IN THE 40S AND 50S. A
POTENT UPR LEVEL TROF WILL STALL OUT OVER THE NRN PLAINS AND UPR
MISS RIVER VALLEY...DIGGING FURTHER S AND SLIGHTLY PIVOTING TO
ENHANCE LIFT AND ALSO ALLOW A PROLONGED STREAM OF SRN MOISTURE TO
ADVECT WELL N INTO THIS REGION...DEEPENING THE MOISTURE COLUMN.
PWATS SURGE TO WELL OVER AN INCH THRU TNGT. IN ADDITION...MOST
RAIN/SNOW LAYER THRESHOLDS BECOME MUCH SHORTER PER BUFKIT PROFILES
BY LATE AFTN...INDICATING THAT THE PRECIP FALLING WILL TAKE THE
FORM OF SNOW RATHER THAN RAIN...HIGHLY UNUSUAL FOR THE MONTH OF
MAY. IN FACT...LOCAL HOPWRF GUIDANCE SHOWS SEVERAL SWATHS OF 1-3
IN/HR SNOW BANDS INTO CENTRAL-ERN MN BY MIDDAY WHICH MAKES SENSE
GIVEN THAT SPC SREF AND RAP GUIDANCE INDICATES VERY STRONG H7
FGEN. THE MAIN CONCERN IS THAT DEWPOINTS ARE STILL IN THE LOWER
20S WHERE TEMPS HAVE DROPPED TO THE FREEZING MARK. SHOULD
WETBULBING EFFECTS OCCUR...DROPPING THE TEMP FASTER THAN
ADVERTISED AND KEEPING IT THERE...ACCUMULATIONS COULD OCCUR
QUICKER AND EARLIER THAN ADVERTISED DESPITE THE WARM ROAD SFC
TEMPS OF THE PAST SEVERAL DAYS. COULD SEE 1-3 INCHES OF SOLID
ACCUMULATION THIS AFTN ONCE THE RAIN CHANGES OVER TO SNOW AND
INTENSITY IS MOD-HVY. WILL STILL LOOK FOR TEMPS TO FALL THRU THE
DAY TDA AND TNGT AS THE UPR TROF CONTINUES TO DIG OVER THE DAKOTAS
AND SFC WINDS SHIFT TO NW-N. GOING INTO TNGT...AT LEAST ONE HVY
BAND OF SNOW IS EXPECTED TO DEVELOP FROM NRN IA INTO SRN AND SE
MN...WITH STRONG FGEN OVER THIS SAME AREA LASTING THROUGH
DAYBREAK ON THU. BUFKIT SOUNDINGS STILL SHOW SOLID SUBFREEZING
SOUNDINGS WITH MOD-HVY SNOW ALONG A MANKATO-MINNEAPOLIS-BARRON
LINE WHERE 6-9 INCHES OF ACCUMULATION IS CERTAINLY WITHIN REASON
IN THIS FORECAST. GOING FURTHER E AND W...ACCUMULATIONS DROP OFF
IN A RATHER TIGHT GRADIENT...SUCH THAT NWRN PORTIONS OF THE MPX
CWFA MAY NOT EVEN SEE 1 INCH. THAT SAID...WPC GUIDANCE STILL PINS
A 8-10 INCH SWATH OF SNOWFALL OVER S-CENTRAL MN INTO E-CENTRAL MN
AND W-CENTRAL WI...AND WITH QPF NEARING AN INCH...EVEN SNOWFALL
RATIOS IN THE 4 OR 5 TO 1 AREA PRODUCE A STORM TOTAL OF 4-7
INCHES THRU TNGT WITH SLIGHT ADDITIONS FOR THU. NORMALLY THE
WARMER GROUND WOULD BE ABLE TO MELT THE SNOW AS IT FALLS...AND THE
WET NATURE OF THE SNOW WOULD ALSO HINDER ACCUMULATIONS. HOWEVER...
THE STRONG FGEN WITH HIGH SNOWFALL RATES FOR SEEM TO COMBAT THAT
THINKING IN THIS CASE...LEANING MORE TWD AGREEMENT WITH THE WPC
OUTPUT.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 441 AM CDT WED MAY 1 2013
MODEL AGREEMENT THIS PERIOD REMAINS HIGH THROUGH FRIDAY...BUT
QUICKLY DISAPPEARS FROM FRIDAY NIGHT ONWARDS WITH HOW EACH MODEL
HANDLES THE PROGRESSION OF WHAT WILL BE A CUT OFF LOW THAT SETS UP
NEAR KANSAS CITY BY SATURDAY MORNING. ABOUT THE ONLY THING THERE IS
AGREEMENT ON BEYOND FRIDAY IS THAT HEIGHTS WILL SLOWLY MODIFY FROM
THE WEEKEND INTO NEXT WEEK...WHICH WILL ALLOW HIGHS TO WORK BACK
CLOSER TO EARLY MAY NORMALS.
FOR THURSDAY...FGEN INDUCED BAND OF HEAVY PRECIPITATION WILL
SLOWLY MOVE INTO WRN WI THU MORNING...AND LOOKS TO SPEND MOST OF
THE DAY CONFINED TO AREAS EAST OF AN ALBERT LEA TO RUSH CITY LINE.
GIVEN EXPECTED PERSISTENT PRECIPITATION AND CLOUD COVER...NUDGED
HIGHS DOWN INTO THE MID 30S FOR THURSDAY ACROSS ERN AREAS...WHICH
IS ABOUT 30 DEGREES BELOW NORMAL. OF COURSE THE OTHER IMPACT OF
THE COOLER TEMPS FOR THURSDAY IS THIS MAY ALLOW SNOW TO BE THE
PREDOMINATE P-TYPE FROM WED NIGHT RIGHT THROUGH THE DAY ON
THURSDAY. THE ONLY THING THAT HAS REALLY CHANGED IS A WESTWARD
SHIFT IN THE WARM NOSE BETWEEN H8 AND H7. THE GFS IN PARTICULAR
BRINGS THIS OUT TO ABOUT AN EAU CLAIRE TO LADYSMITH LINE...WITH A
PRETTY SHARP GRADIENT IN POTENTIAL SNOW TOTALS RESULTING ACROSS
THE ERN CWA...WITH VERY LITTLE ACCUMS AT AUGUSTA...WHILE A
MENOMONIE WOULD HAVE THE POTENTIAL FOR AROUND 8 INCHES. GIVEN THE
COOLER TEMPERATURES FOR THURSDAY AND THE POTENTIAL FOR CONTINUED
SNOW ACCUMS THROUGH THE DAY...WE DECIDED TO CARRY WINTER HEADLINES
THROUGH 00Z /7 PM THU/. AS WITH THE SHORT TERM...SNOW TOTALS ARE
TRICKY HERE AS GIVEN THE RATHER HIGH QPF NUMBERS...EVEN
POTENTIALLY UNREALISTIC SNOW RATIOS OF 4-6:1 STILL YIELD SNOWFALL
AMOUNTS THAT ARE OFF INTO UNCHARTED TERRITORY FOR MAY SNOWFALLS IN
THIS AREA. CURRENT GRIDS HAVE ABOUT A 100 MILE WIDE SWATH OF 6-9
INCHES OF SNOW THAT IS CENTERED ALONG A BLUE EARTH /CITY/...TO
HASTINGS...TO CUMBERLAND...WI LINE.
THOUGH CERTAINLY THE WARM SOILS/PAVEMENT TEMPS FROM THE RECENT
WARM SPELL WILL HAVE THE POTENTIAL TO LIMIT ACCUMULATIONS...
EXPECTED SNOWFALL RATES FROM TONIGHT INTO AT LEAST THURSDAY
MORNING IN THE 1-2 INCH PLUS RANGE WILL BE MORE THAN ENOUGH TO
ACCUMULATE ON ANY SURFACE WHILE THOSE TYPES OF RATES ARE BEING
OBSERVED. THERE IS CERTAINLY POTENTIAL FOR SNOWFALL AMOUNTS TO GO
EITHER WAY /HIGHER OR LOWER/ WITH THIS SYSTEM...BUT IF THE CURRENT
FORECAST DOES PAN OUT...THIS STORM WILL CERTAINLY BE RE- WRITING
THE RECORD BOOKS FOR MAY SNOWFALL ACROSS SOUTHERN MN AND WRN WI.
FOR THURSDAY NIGHT INTO FRIDAY...THE FOCUS FOR THE HEAVY
PRECIPITATION SHIFTS EAST FROM ERN IA INTO CENTRAL WI AS LLJ
SLOWLY SHIFTS EAST. AS RESULT...HAVE CUT BACK ON POPS IN THIS
PERIOD... ESPECIALLY ACROSS MN...WITH MUCH OF THE AREA LIKELY
SEEING A BIT OF A REPRIEVE FROM THE PRECIPITATION. IN
ADDITION...WRN MN WILL LIKELY SEE SOME FILTERED SUNSHINE...WHICH
WILL ALLOW WRN AREAS TO WARM BACK TOWARD THE 50S.
FOR FRIDAY NIGHT...MODEL DISAGREEMENTS START TO INCREASE
DRAMATICALLY WITH HANDLING OF A SURGE OF WAA ADVECTIVE PRECIP THAT
WILL BE COMING IN FROM THE SE AS A STRONG VORT MAX ROTATES
AROUND THE MAIN UPPER LOW OVER NRN MO /OFF THE NAM ANYWAYS/. THE
NAM IS THE MIDDLE MEMBER WITH THIS FEATURE...BRINGING ANOTHER
SHIELD OF HEAVY PRECIPITATION ACROSS THE MPX CWA FRIDAY NIGHT INTO
SATURDAY MORNING. THE GFS HAS A SIMILAR FEATURE...BUT KEEPS THE
BRUNT OF THE PRECIPITATION DOWN ACROSS IA. THE ECMWF HAS A
COMPLETELY DIFFERENT IDEA WITH HOW THIS UPPER LOW WILL EVOLVE.
WHERE THE GFS ON SAT HAS THE UPPER LOW OVER NRN ARK...THE NAM OVER
NRN MO...THE 01.00 ECMWF HAS THE SAME...MUCH SHALLOWER LOW UP NEAR
THE MN/DAKOTAS BORDER! GIVEN THE DISAGREEMENTS...HELD POPS TO NO
HIGHER THAN LIKELY ON SATURDAY AS IT COULD RANGE FROM ANYWHERE
BETWEEN A WASHOUT TO JUST COOL AND CLOUDY. AT THE VERY LEAST...AT
LEAST THIS POTENTIAL WAVE OF PRECIPITATION LOOKS TO BE WARM ENOUGH
TO KEEP EVERYTHING LIQUID.
GOING INTO NEXT WORK WEEK...BOTH THE GFS AND THE ECMWF SHOW
ANOTHER OMEGA BLOCK DEVELOPING...ONLY THIS TIME ACROSS THE WRN
US. THE ECMWF IS THE FARTHEST WEST WITH THIS FEATURE...WHICH
ALLOWS IT TO SEND ANOTHER STRONG SHORTWAVE AND COLD FRONT THROUGH
THE MPX AREA MONDAY NIGHT INTO TUESDAY. THE GFS HAS THE BLOCK
FARTHER EAST AND WOULD KEEP THE REGION DRY. AT THIS POINT...KEPT
THE MAINLY CHANCE POPS THAT WERE IN PLACE DURING THIS TIME FRAME.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 643 AM CDT WED MAY 1 2013
CDFNT WILL SETTLE S AND E OF THE AREA THRU TMRW MRNG WHILE SEVERAL
WAVES OF LOW PRES RIDE NE ALONG THE STALLED FRONT. SIGNIFICANT
INCRS IN MOISTURE FROM THE S WHILE WINDS SHIFT ARND TO NLY WILL
CREATE A WINTRY P-TYPE ISSUE ALONG WITH THE POTENTIAL FOR
SIGNIFICANT SNOW ACCUMULATION. PRECIP CURRENTLY MOVING SW-NE ACRS
SRN-CENTRAL MN INTO NW WI...MOSTLY AS -RA ALTHOUGH AM ALREADY
SEEING OBS REPORTING -SN...INCLUDING KRWF. COLDER AIR MAKING
STRONG PROGRESS INTO WRN AND SWRN MN...AND WILL CONTINUE TO MOVE E
THROUGH THE REST OF MN TDA AND INTO WI LATER THIS AFTN INTO TNGT.
THIS WILL GRADUALLY CHANGE OVER THE PRECIP FROM -RA TO -SN...AND
INTENSITIES MAY EASILY AND IN A SHORT DURATION INCRS FROM LGT TO
HVY...SIGNIFICANTLY IMPACTING VSBY WITH LITTLE ADVANCE NOTICE. THE
ONLY SITES EXPECTED TO GET AWAY UNSCATHED LOOKS TO BE KAXN-KSTC.
THE REST OF THE TAF SITES ARE EXPECTED TO SEE -RA CHANGING TO
-SN...WITH KEAU THE LAST. KMSP LOOKS TO BE THE MOST SIGNIFICANTLY
IMPACTED AS KMSP IS CENTERED WITHIN THE HEAVIEST BAND OF PRECIP.
AS ALL SITES CHANGE OVER TO -SN...BOTH CIGS AND VSBYS WILL BE
IMPACTED...LIKELY TO IFR...BUT THE TIMING IS STILL QUESTIONABLE SO
FREQUENT AMENDMENTS MAY BE NECESSARY.
KMSP...CONDS TO DETERIORATE STEADILY THRU THE DAY AS MOISTURE
SURGING FROM THE SW BRINGS RAIN...LGT TO MOD...TO THE FIELD THIS
MRNG. AS COLDER AIR SHIFTS SE INTO THE AREA...THE PRECIP WILL
CHANGE OVER TO -SN BY LATE AFTN. COULD BE AN ABRUPT CHANGEOVER AT
TIMES...THE TIMING OF WHICH COULD BE QUITE TROUBLESOME TO PIN
DOWN. HENCE THE INCLUSION OF SEVERAL TEMPO GROUPS THROUGH THE
FIRST HALF OF THE 01/12Z TAF. PRECIP IS EXPECTED TO FULLY CHANGE
OVER TO SNOW BY LATE AFTN...AND THE SNOW WILL THEN PERSIST
OVERNIGHT THRU TMRW MRNG. WILL LOOK FOR A POTENTIALLY SIGNIFICANT
SNOWFALL ACCUMULATION OF WET SNOW...AND MAY OCCUR RAPIDLY AT TIMES
WITH RATES OF 1-2 INCHES PER HOUR POSSIBLE. CONDS WILL GRADUALLY
IMPROVE LATE TMRW MRNG INTO TMRW AFTN AS THE STALLED CDFNT SHIFTS
AWAY.
/OUTLOOK FOR KMSP/
FRI...MVFR CIGS/VSBYS POSSIBLE WITH CHC -RA/-SN. NE WINDS 10-15
KT.
SAT...MVFR CIGS/VSBYS POSSIBLE WITH CHC -RA. ENE WINDS 5 KT.
SUN...MVFR CIGS/VSBYS POSSIBLE WITH CHC -RA. LGT/VRBL WINDS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WINTER STORM WARNING FROM 3 PM THIS AFTERNOON TO 7 PM CDT
THURSDAY FOR MNZ053-060>063-067>070-074>078-082>085-091>093.
WINTER WEATHER ADVISORY FROM 3 PM THIS AFTERNOON TO 7 PM CDT
THURSDAY FOR MNZ044-045-051-052-058-059-065-066-073.
WI...WINTER STORM WARNING FROM 3 PM THIS AFTERNOON TO 7 PM CDT
THURSDAY FOR WIZ014>016-023>025.
WINTER WEATHER ADVISORY FROM 3 PM THIS AFTERNOON TO 7 PM CDT
THURSDAY FOR WIZ026>028.
&&
$$
UPDATE...JPC
SHORT TERM...JPC
LONG TERM...MPG
AVIATION...JPC
AREA FORECAST DISCUSSION...UPDATED
NWS MORRISTOWN TN
947 AM EDT WED MAY 1 2013
.DISCUSSION...
12Z RAOBS FROM OHX...FFC...AND GSO SHOW AN INVERSION AROUND 750
MB...WHICH SHOULD HELP CAP CONVECTION TODAY IN MOST LOCATIONS. THE
LATEST RUC SOUNDINGS SHOW THIS INVERSION WEAKENING A BIT THIS
AFTERNOON ACROSS THE CUMBERLAND PLATEAU. IF ANY SHOWERS ARE ABLE TO
DEVELOP...THAT WOULD PROBABLY BE THE AREA IT WOULD OCCUR WITH THE
MIDLEVEL RIDGE AXIS TO OUR EAST. THE CURRENT FORECAST HAS A SLIGHT
CHANCE POP IN THE NORTHERN PLATEAU...AND THIS SEEMS REASONABLE.
FORECAST TEMPS LOOK A BIT COOL NORTH BASED ON THE LATEST OBS AND
GUIDANCE...AND LACK OF CLOUD COVER SO FAR. TRI SHOULD BE AT LEAST
AS WARM AS YESTERDAY WHEN THE HIGH REACHED 80. WILL ISSUE AN UPDATE
FOR TEMPS IN THAT AREA.
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
DGS
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
348 PM EDT WED MAY 1 2013
.DISCUSSION...
...HEAVY RAIN MOVING NORTH ACROSS LAKE OKEECHOBEE AND THE TREASURE
COAST REGION THIS AFTERNOON...
CURRENT...LARGE SQUALL LINE EXTENDING FROM TAMPA BAY TO THE SW
SHORE OF LAKE OKEECHOBEE WILL LIFT N INTO E CENTRAL FL THRU THE
REMAINDER OF THE AFTN. SCT SHRAS/ISOLD TSRAS DVLPG BCMG NMRS THRU
LATE AFTN. HEAVY RAIN AND FQNT CG LTG PRIMARY THREATS. NO
INDICATIONS OF SVR WND/HAIL FROM WFO TAMPA OR WFO MIAMI...THOUGH
STORMS OVER LAKE OKEECHOBEE HAVE PROMPTED SPECIAL MARINE WARNINGS.
SCT SHRAS/ISOLD TSRAS HAVE DVLPD ALONG AND N OF THE FL
TURNPIKE...EXPECT THIS ACTIVITY WILL ROB THE SQUALL LINE OF MUCH
OF THE NECESSARY ENERGY TO GENERATE SVR WX...THOUGH 40-50MPH SFC
GUSTS WILL BE POSSIBLE THRU EARLY EVENING. TEMPS ALOFT HAVE WARMED
A TOUCH...BUT RUC ANALYSIS STILL SHOWS MUCH OF CENTRAL FL BTWN
-10C AND -11C.
SCT/NMRS SHRAS AND ISOLD TSRAS WILL LINGER INTO LATE EVNG WITH
ACTIVITY DIMINISHING AS SFC BNDRY INTERACTIONS PLAY OUT. MOIST
ONSHORE FLOW WILL ALLOW FOR A SCT COASTAL SHOWERS THROUGH THE
OVERNIGHT HOURS...ESPECIALLY AS ADDITIONAL RIPPLES OF H85-H50
VORTICITY OVER THE ERN AND CENTRAL GOMEX WORK THEIR WAY ACRS THE FL
PENINSULA. MILD NIGHT WITH LOWS IN THE M/U60S...L70S PSBL ALONG THE
IMMEDIATE TREASURE COAST.
THURSDAY...
ANOTHER ROUND OF RAIN IN THE WORKS FOR E CNTRL FL. SHORT WAVE TROF
AXIS CENTERED OVER THE LWR MS VALLEY WILL REMAIN NEARLY STATIONARY
WITH ITS ASSOCD SFC LOW SAGGING INTO THE ERN GULF. INTERACTION BTWN
THE TROF AND A STRONG SFC RIDGE PARKED ALONG THE ERN SEABOARD WILL
ALLOW WINDS TO FRESHEN OUT OF THE E/NE. DEEP MOISTURE POOLING WITHIN
THE TROF WILL REMAIN OVER CENTRAL FL...KEEPING PWATS BTWN 1.5"-1.6".
SRN BRANCH OF THE JET STREAM WILL REMAIN S OF CENTRAL FL WHERE IT
WILL CONTINUE TO PRODUCE STRONG UPR LVL DIVERGENCE. TEMPS ALOFT WILL
TAKE ANOTHER DIP AS H50 TEMPS BTWN -12C AND -14C OVER THE NW GOMEX
WORK THEMSELVES INTO THE REGION.
MOS GUIDANCE CONTINUES TO INDICATE POPS NEAR OR ABV 70PCT...GIVING
IT GOOD RUN-TO-RUN CONSISTENCY. CAN SEE NO AREA THAT IS OVERLY
FAVORED...WILL PAINT THE ENTIRE CWA WITH 70PCT. THE INCREASED LOW
LEVEL FLOW WILL ENHANCE THE POTENTIAL FOR HEAVY RAIN.
FRI-SUN...(PREVIOUS) THE NAM AND GFS SHOW THE WEAK SURFACE LOW
PUSHING EAST TOWARDS THE SOUTHERN PART OF THE STATE. THIS WOULD
KEEP THE AREA IN A MOIST ONSHORE WIND FLOW. THERE IS SOME
UNCERTAINTY THOUGH IN THE EVOLUTION OF THIS SYSTEM AS THE 00Z
ECMWF SHOWS A BROAD LOW OVER THE STATE BY THE WEEKEND. WILL FOLLOW
CLOSER TO THE GFS THOUGH AS THE SURFACE HIGH PRESSURE RIDGE OVER
THE EASTERN SEABOARD SHOULD SUSTAIN AN ONSHORE WIND. THIS IS IN
AGREEMENT WITH THE LATEST WPC PROGS.
WITH BREEZY EASTERLY FLOW...THERE SHOULD BE A CONTINUED CHANCE FOR
HEAVY RAIN...ESPECIALLY FRI AND MAYBE INTO SAT. WILL FOLLOW CLOSE
TO MOS POPS AND HAVE INDICATED 50-60 PERCENT RAIN CHANCES FOR FRI-
SAT.
TAKEN AT FACE VALUE...THE GFS SOLUTION ALSO SHOWS LOW LEVEL
VEERING FLOW DUE TO THE APPROACHING SURFACE LOW. THIS COULD BRING
A SLIGHT RISK OF TORNADOES. BY SUN BOTH THE GFS AND ECMWF SHOW
DRYING AND HAVE FOLLOWED THE PREVIOUS FORECAST TREND FOR LOWERING
POPS.
MON-WED...THE MEDIUM RANGE MODELS DIVERGE WITH THE GFS SHOWING A
LOW PRESSURE CENTER VICINITY OF THE MID ATLANTIC COAST...WHICH
PUSHES A WEAK FRONT THROUGH THE LOCAL AREA. THE ECMWF INDICATES A
BROAD LOW FARTHER SOUTH AND WEAKER...WITH BASICALLY AN ONSHORE
WIND FLOW DUE TO THE LARGE SURFACE HIGH PRESSURE RIDGE ALONG THE
EASTERN SEABOARD. THIS SOLUTION IS CLOSER TO THE WPC PROGS SO HAVE
FOLLOWED CLOSE TO THAT SCENARIO FOR NOW. WILL CARRY SLIGHT CHANCE
POPS MON THEN MAINTAIN THE DRYING TREND FROM THE PREVIOUS
FORECAST. OF COURSE...THIS PART OF THE FORECAST COULD BE SUBJECT
TO SIGNIFICANT CHANGES.
&&
.AVIATION...
THRU 02/00Z...SQLN LN EXTENDING FROM LAKE OKEECHOBEE TO TAMPA BAY
WILL LIFT N/NE...NMRS MVFR SHRAS/SCT IFR TSRAS DVLPG ALL SITES BCMG
WDSPRD W OF I-95...ISOLD LIFR CIGS/VSBYS IN +TSRA WITH SFC WND
G35KTS PSBL. BTWN 02/02Z-02/04Z...TSRAS ENDING...CHC OF MVFR SHRAS
ALL SITES CONTG THRU 02/14Z...AREAS MVFR CIGS N OF KMLB-KISM.
&&
.MARINE...
TONIGHT-THURSDAY...WINDS WILL FRESHEN OUT OF THE E/NE AS A HIGH PRES
RIDGE OVER THE ERN SEABOARD INTERACTS WITH A DLVPG STORM SYSTEM OVER
THE GOMEX. FRESH SWELL WILL WORK ITS WAY INTO THE LCL ATLC AS THE
WINDS INCREASE...SEAS 4-5FT OVERNIGHT WILL BUILD TO 5-6FT NEARSHORE
AND 6-8FT OFFSHORE...DOMINANT PDS SHORTENING TO 9-10SEC.
FRI...(PREVIOUS) SURFACE HIGH PRESSURE RIDGE ALONG THE EASTERN
SEABOARD AND WEAK LOW PRESSURE IN THE EASTERN GULF SHOULD LEAD TO
CONTINUED FRESH EASTERLY WINDS WITH MOST OF THE WATERS WILL BE
AROUND 20+ KNOTS. IN ADDITION...INCREASING LOW LEVEL CONVERGENCE
SHOULD PRODUCE BANDS OF SHOWERS/STORMS WITH A FAIRLY HIGH COVERAGE
EXPECTED.
WEEKEND...THE FORECAST DEPENDS ON THE EVOLUTION OF THE SURFACE LOW
THAT IS FORECAST TO BE PUSHING ACROSS THE SOUTHERN PART OF THE
STATE. RIGHT NOW IT LOOKS LIKE ADVISORY CONDITIONS MIGHT BE
CONTINUING ON SAT WITH GRADUALLY DECREASING EAST WINDS ON SUNDAY.
CONFIDENCE IS NOT HIGH THOUGH...SO MARINERS WILL NEED TO MONITOR
THE LATEST FORECAST TRENDS FOR THE WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 66 77 66 80 / 50 70 50 50
MCO 66 83 65 84 / 50 70 50 60
MLB 68 80 69 80 / 50 70 50 60
VRB 68 80 68 81 / 50 70 40 60
LEE 65 83 65 83 / 50 70 40 60
SFB 65 83 65 83 / 50 70 50 50
ORL 66 83 67 83 / 50 70 50 60
FPR 68 79 67 82 / 60 70 40 60
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM...BRAGAW
LONG TERM....PENDERGRAST
RADAR...VOLKMER
AREA FORECAST DISCUSSION
NWS MIAMI FL
238 PM EDT WED MAY 1 2013
.SHORT TERM (TONIGHT THROUGH FRIDAY NIGHT)...
LARGE CUT-OFF MID LEVEL LOW CONTINUES TO SLOWLY DRIFT EAST ACROSS
THE SOUTH CENTRAL GULF STATES. A LARGE CLUSTER OF CONVECTION
DEVELOPED ON THE SOUTHERN FRINGES OF THIS LOW AND HAS MOVED EAST
THROUGH EARLY THIS AFTERNOON AND AS OF 1830Z WAS MOVING ACROSS THE
INTERIOR AND TOWARDS THE EAST COAST METRO AREA. ANOTHER CLUSTER OF
CONVECTION IS ALSO CURRENTLY DEVELOPING OVER THE CENTRAL GULF WITH
THE HRRR SHOWING THIS MOVING ACROSS SOUTH FLORIDA THIS EVENING SO
HAVE INCREASED THE POPS FOR THE OVERNIGHT HOURS. AT THE SAME TIME, A
DEEPENING TROUGH INTO THE CENTRAL PLAINS STATES ON THURSDAY WILL
CONTINUE TO DEEPEN AND CUT OFF OVER THE MISSISSIPPI VALLEY WITH
THE SOUTHERN CUT-OFF LOW BECOMING PHASED IN WITH THIS LOW. THIS
KEEPS SOUTH FLORIDA IN RICH TROPICAL FLOW OF AIR THROUGH THE END
OF THE WEEK WITH HIGH CHANCES FOR SHOWERS AND THUNDERSTORMS.
FORECAST SOUNDINGS THROUGH THIS PERIOD LOOK QUITE SIMILAR WITH
PWAT REMAINING WELL ABOVE NORMAL FOR EARLY MAY AND A WEAK WESTERLY
STEERING FLOW. GLOBAL MODELS ARE NOW MORE IN AGREEMENT WITH THE
OVERALL SOLUTION DURING THE NEXT 48 HOURS AND SHOW THE LOW
DRIFTING TO THE SOUTHEAST BEFORE GETTING PHASED IN WITH THE
UPSTREAM DEEPENING TROUGH. THIS ON THURSDAY AND POSSIBLY FRIDAY
WILL DESTABILIZE THE ATMOSPHERE WITH COOLING 500 MB TEMPERATURES.
THE 12Z MFL SOUNDING SHOWED A TEMPERATURE OF -10 CELSIUS AND THE
GFS SHOWS COOLING TO AROUND -12 ON THURSDAY INTO FRIDAY. SO THE
CONTINUED THREAT FOR STRONG STORMS WILL ALSO BE A FACTOR. OF
COURSE THERE WILL ALWAYS BE SOME DAY TO DAY FLUCTUATIONS WITH WEAK
DISTURBANCES MOVING THROUGH THE BASE OF THE TROUGH.
.LONG TERM (SATURDAY THROUGH WEDNESDAY)...
THE EXTENDED PORTION OF THE FORECAST CONTINUES TO BE HIGHLY
UNCERTAIN WITH THE GFS AND ECMWF HAVING TWO DIFFERENT SOLUTIONS TO
THE DEEPENING TROUGH. BOTH CUT THIS LOW OFF FROM THE NORTHERN
LATITUDE FLOW AS MENTIONED ABOVE. THE GFS THEN DEVELOPS A MASSIVE
CUT-OFF LOW AND THEN SLOWLY DRIFTS IT TO THE EAST THROUGH THE MIDDLE
OF NEXT WEEK. THIS WOULD TEND TO DRAW A DRIER AIR MASS ACROSS SOUTH
FLORIDA FOR LESSER STORM ACTIVITY. HOWEVER, THE ECMWF SPLITS THE
CUT-OFF LOW DRIFTING THE SOUTHERN PORTION TO THE SOUTH WHICH WOULD
KEEP SOUTH FLORIDA VERY UNSTABLE. FOR NOW, WILL GO WITH THE GFS
SOLUTION AS THIS MODEL HAS BEEN THE MOST CONSISTENT IN ITS FORECAST
WHERE THE ECMWF HAS HAD DIFFERENT SOLUTIONS WITH EACH RUN.
&&
.MARINE...
TRANQUIL CONDITIONS OUTSIDE OF ISOLATED STRONG CONVECTION WILL
CONTINUE THROUGH THURSDAY. SOME INCREASE IN A NORTHEAST SWELL IS
EXPECTED LATE IN THE WEEK INTO THE WEEKEND WITH POSSIBLE SEAS
BUILDING TO 7 FEET OVER THE PALM BEACH WATERS.
&&
.FIRE WEATHER...
NO PROBLEMS OR CONCERNS WITH DEEP TROPICAL MOISTURE REMAINING IN PLACE.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 72 81 70 81 / 60 70 50 60
FORT LAUDERDALE 71 81 71 82 / 60 70 50 60
MIAMI 75 81 71 83 / 60 70 50 60
NAPLES 68 85 67 83 / 60 50 40 50
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...30/KOB
AVIATION/RADAR...23/SK
AREA FORECAST DISCUSSION
NWS MIAMI FL
204 PM EDT WED MAY 1 2013
.AVIATION...
SIGNIFICANT TAF CHANGES WITH 18Z UPDATE DUE TO EVOLVING MCS THAT
IS MOVING THROUGH KAPF. PRESENT MOTION PLACES THE LEADING EDGE OF
COMPLEX INTO EAST COAST TERMINALS BY 20Z...SO HAVE ADDED
PREVAILING TSRA FROM 1930-22Z...ALONG WITH MVFR CONDITIONS. LIKELY
IFR RESTRICTIONS FOR RELATIVELY BRIEF TIMES. SIGNIFICANT WINDS ARE
POSSIBLE WITH THE CONVECTIVE BAND...AND GUSTS IN EXCESS OF 35 KTS
ARE REALISTIC. SHOWERS AND THUNDERSTORMS COULD CONTINUE
OVERNIGHT...AND WILL LIKELY REINVIGORATE DURING THE MORNING
THURSDAY. VCSH WARRANTED BUT CONFIDENCE TOO LOW FOR PREVAIL PCPN ATTM.
&&
.PREV DISCUSSION... /ISSUED 943 AM EDT WED MAY 1 2013/
UPDATE...
MASSIVE CLOUD FIELD CURRENTLY OVER THE EASTERN GOFMEX ASSOCIATED
WITH LARGE CONVECTIVE COMPLEX ROTATING BENEATH CUT-OFF LOW WHICH
IS OVER THE SOUTH CENTRAL GULF STATES. THIS LINE OF CONVECTION
HAS BEEN PRODUCING A TREMENDOUS AMOUNT OF LIGHTNING WITH NEARLY 800
STRIKES IN THE PAST 15 MINUTES. THE CONVECTIVE FIELD IS MOVING
EAST BUT THE QUESTION IS IF IT WILL HOLD TOGETHER BEFORE REACHING
THE LOCAL GULF WATERS AND HOW MUCH EFFECT THE DEBRIS CLOUD FIELD
WILL HAVE ON DIURNAL HEATING OVER THE MAINLAND. FORECAST SOUNDINGS
ALONG WITH THE 12Z MFL SOUNDING WOULD SUGGEST THE POSSIBILITY OF
AT LEAST SOME STRONG STORMS ESPECIALLY ALONG THE EAST COAST WITH
THE LOW LEVEL SOUTHEAST FLOW. HOWEVER, IT IS ALSO POSSIBLE THAT
HEATING WILL BE HELD OFF ENOUGH TO NOT ALLOW SIGNIFICANT UPDRAFTS
TO OCCUR. THE HRRR IS SHOWING SOME WEAKENING AS THE SYSTEM
APPROACHES THE GULF COAST BUT WITH ADDITIONAL DEVELOPMENT OVER THE
MAINLAND AS SOME HEATING TAKES PLACE WITH MOVEMENT TOWARDS THE
EAST COAST. THE 12Z MFL SOUNDING DOES INDICATE A STORM MOTION TO
THE EAST AT AROUND 5 KNOTS. ALL OF THIS SAID, CURRENT THINKING IS
TO ADD MENTION OF POSSIBLE STRONG STORMS FOR THIS AFTERNOON AND
EXTEND HIGHER POPS BACK TO THE WEST COAST TO ACCOUNT FOR THE
APPROACHING CONVECTION.
KOB
PREV DISCUSSION... /ISSUED 807 AM EDT WED MAY 1 2013/
AVIATION...
TODAY WILL LIKELY BE A REPLAY OF THE LAST COUPLE OF DAYS, ONCE AGAIN.
EXPECT SOME CONVECTIVE SHOWER ACTIVITY IN THE MORNING, THEN THUNDERSTORMS
TO DEVELOP IN THE LATE MORNING TO EARLY AFTERNOON. THESE CAN LEAD TO
MVFR AND IFR CONDITIONS AT TIMES. HAVE ADDED PROB30 GROUPS TO ALL EAST
COAST TAF SITES FOR THE AFTERNOON HOURS. THIS TIME THERE IS A BETTER
CHANCE TSTMS COULD LINGER INTO THE EVENING HOURS SO LEFT VCTS IN THE
FORECAST FOR THE EVENING HOURS ALSO. WINDS WILL BE LIGHT AND VARIABLE
THIS MORNING AND PICK UP OUT OF THE SOUTHEAST MID TO LATE MORNING AROUND
10 KTS WITH A CHANCE OF A SOUTHWEST SEA BREEZE OF 5 T0 10 KNOTS AT APF
IN THE MID TO LATE AFTERNOON FOR A COUPLE OF HOURS.
PREV DISCUSSION... /ISSUED 416 AM EDT WED MAY 1 2013/
WET WEATHER CONTINUES OVER SOUTH FLORIDA THROUGH EARLY THIS WEEKEND...
SOME STRONG STORMS POSSIBLE TODAY AND AGAIN THURSDAY OVER SOUTH FLORIDA...
SHORT TERM...
LOW PRESSURE OVER THE WESTERN ATLANTIC WATERS WILL MOVE EAST TODAY
AS A MID TO UPPER LEVEL LOW OVER THE SOUTHERN GULF COAST STATES
MOVES SOUTHEAST INTO THE NORTHERN GULF OF MEXICO. THIS WILL ALLOW
FOR A TROUGH OF LOW PRESSURE OVER CENTRAL FLORIDA TO MOVE SOUTH INTO
THE LAKE OKEECHOBEE REGION TODAY KEEPING THE STEERING FLOW IN A
SOUTH TO SOUTHWEST DIRECTION OVER SOUTH FLORIDA. SO THE DEEP
TROPICAL MOISTURE WILL CONTINUE TO WORK INTO THE AREA FROM THE SOUTH
ALLOWING FOR SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS. THE
STORMS WILL ALSO BE SLOW MOVERS TODAY LEADING TO HEAVY RAINFALL OVER
SOUTH FLORIDA. SO WILL CONTINUE TO MENTION THE HEAVY RAINFALL IN THE
ZONES FOR TODAY OVER SOUTH FLORIDA.
THE TROUGH OF LOW PRESSURE WILL REMAIN NEARLY STATIONARY TONIGHT
INTO THURSDAY...AS THE MID TO UPPER LEVEL LOW MOVES SLOWLY
SOUTHEAST INTO THE EASTERN GULF OF MEXICO. A SURFACE LOW WILL
ALSO DEVELOP IN THE EASTERN GULF OF MEXICO ON THURSDAY WHICH WILL
HELP KEEP THE SOUTH TO SOUTHWEST STEERING FLOW OVER SOUTH FLORIDA
ALONG WITH THE DEEP TROPICAL MOISTURE. SO WILL CONTINUE THE
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS OVER SOUTH FLORIDA
FOR THURSDAY ALONG WITH THE HEAVY RAINFALL WORDING.
THE 500 MB TEMPS WILL ALSO COOL OFF A BIT FROM AROUND -10C THIS
MORNING TO -12C TO -13C ON THURSDAY. THIS WILL ALLOW FOR SOME STRONG
STORMS OVER SOUTH FLORIDA TODAY...AND STRONG TO EVEN SEVERE STORMS
(WITH POTENTIAL FOR MORE THAN THE ORDINARY DEPENDING HOW MUCH
SURFACE HEATING WE END UP GETTING) ON THURSDAY OVER SOUTH FLORIDA.
ALTHOUGH THE PRIMARY THREAT FROM THE STORMS WILL CONTINUE TO BE
FLOODING POTENTIAL...SECONDARY THREATS FROM THE STORMS WILL BE GUSTY
WINDS...HAIL...AND FREQUENT LIGHTING STRIKES.
THE LOW OVER THE EASTERN GULF OF MEXICO WILL SLOWLY MOVE EAST ON
FRIDAY TOWARDS SOUTH FLORIDA...AS THE TROUGH OF LOW PRESSURE
REMAINS OVER SOUTH FLORIDA. THIS WILL CONTINUE TO KEEP THE DEEP
TROPICAL MOISTURE IN PLACE OVER SOUTH FLORIDA ON FRIDAY. SO WILL
CONTINUE THE SCATTERED TO NUMEROUS POPS OVER THE AREA FOR FRIDAY
ALONG WITH THE HEAVY RAINFALL WORDING.
LONG TERM...
THE LOW WILL MOVE EAST OVER SOUTH FLORIDA ON SATURDAY BEFORE
MOVING INTO THE WESTERN ATLANTIC WATERS ON SUNDAY. THIS WILL KEEP
THE AREA IN THE DEEP TROPICAL MOISTURE ON SATURDAY...BEFORE
ALLOWING FOR SOME DRIER AIR TO WORK INTO THE AREA FROM THE WEST ON
SUNDAY. THEREFORE...THE POPS ON SATURDAY WILL BE IN THE SCATTERED
RANGE OVER SOUTH FLORIDA WHILE ON SUNDAY THE POPS WILL BE IN SLIGHT
CHANCE TO LOW END CHANCE.
FOR EARLY NEXT WEEK...THE DRIER WEATHER WILL CONTINUE TO WORK INTO
THE AREA FROM THE NORTH AND WEST. SO THE WEATHER SHOULD BE DRY
OVER SOUTH FLORIDA FOR EARLY NEXT WEEK...AND WILL REMOVE THE SHOWER
AND THUNDERSTORM WORDING OVER SOUTH FLORIDA FOR EARLY NEXT WEEK.
HOWEVER...THERE REMAINS QUITE A BIT OF UNCERTAINTY AMONG THE MODELS
AND THIS OUTLOOK COULD CHANGE WITH THE WET PERIOD EITHER ENDING
EARLIER THAN SUNDAY OR LATER THAN ANTICIPATED INTO EARLY NEXT WEEK.
MARINE...
THE WINDS OVER SOUTH FLORIDA TODAY INTO THURSDAY WILL BE FROM THE
EAST TO SOUTHEAST AT 10 KNOTS OR LESS...BEFORE INCREASING TO
BREEZY CONDITIONS BY EARLY THIS WEEKEND FROM THE SOUTHERLY
DIRECTION. AT THE SAME TIME...A NORTHEAST SWELL OF 2 TO 3 FEET
WILL ALSO CONTINUE TO AFFECT THE PALM BEACH WATERS OF SOUTH
FLORIDA. THIS WILL ALLOW FOR THE SEAS TO REMAIN BELOW 6 FEET IN
THE ATLANTIC WATERS TODAY INTO THURSDAY...BEFORE INCREASING TO 7
FEET BY FRIDAY IN THE PALM BEACH WATERS. FOR THE GULF SIDE...THE
SEAS WILL REMAIN BELOW 6 FEET TODAY INTO EARLY THIS WEEKEND.
FIRE WEATHER...
THE RELATIVE HUMIDITIES WILL REMAIN ABOVE THE 35 PERCENT CRITICAL
VALUE EACH DAY OVER SOUTH FLORIDA THROUGH END OF THIS WEEK...DUE
TO THE TROPICAL MOISTURE REMAINING OVER THE AREA. SO NO PROBLEMS
ARE EXPECTED WITH THE FIRE WEATHER OVER SOUTH FLORIDA.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 70 82 70 82 / 50 70 50 60
FORT LAUDERDALE 71 82 71 83 / 50 70 50 60
MIAMI 71 83 71 84 / 50 70 50 60
NAPLES 68 85 68 85 / 50 50 40 50
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...30/KOB
AVIATION/RADAR...23/SK
AREA FORECAST DISCUSSION...UPDATED
NWS TWIN CITIES/CHANHASSEN MN
149 PM CDT WED MAY 1 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 441 AM CDT WED MAY 1 2013
NOT THE TYPICAL MAY FORECAST. CDFNT HAS SETTLED OVER SE WI AND
STRETCHES SWWD INTO CENTRAL AND SRN IA...AND WILL REMAIN QUASI-
STNRY OVER THESE AREAS THRU THE NEXT 24 HRS. SIGNIFICANT CAA IS IN
PROGRESS AS EVIDENCED BY TEMPS IN THE LOW 30S IN NRN AND WRN MN
WHILE THE ERN AND SRN MN INTO WRN WI IS IN THE 40S AND 50S. A
POTENT UPR LEVEL TROF WILL STALL OUT OVER THE NRN PLAINS AND UPR
MISS RIVER VALLEY...DIGGING FURTHER S AND SLIGHTLY PIVOTING TO
ENHANCE LIFT AND ALSO ALLOW A PROLONGED STREAM OF SRN MOISTURE TO
ADVECT WELL N INTO THIS REGION...DEEPENING THE MOISTURE COLUMN.
PWATS SURGE TO WELL OVER AN INCH THRU TNGT. IN ADDITION...MOST
RAIN/SNOW LAYER THRESHOLDS BECOME MUCH SHORTER PER BUFKIT PROFILES
BY LATE AFTN...INDICATING THAT THE PRECIP FALLING WILL TAKE THE
FORM OF SNOW RATHER THAN RAIN...HIGHLY UNUSUAL FOR THE MONTH OF
MAY. IN FACT...LOCAL HOPWRF GUIDANCE SHOWS SEVERAL SWATHS OF 1-3
IN/HR SNOW BANDS INTO CENTRAL-ERN MN BY MIDDAY WHICH MAKES SENSE
GIVEN THAT SPC SREF AND RAP GUIDANCE INDICATES VERY STRONG H7
FGEN. THE MAIN CONCERN IS THAT DEWPOINTS ARE STILL IN THE LOWER
20S WHERE TEMPS HAVE DROPPED TO THE FREEZING MARK. SHOULD
WETBULBING EFFECTS OCCUR...DROPPING THE TEMP FASTER THAN
ADVERTISED AND KEEPING IT THERE...ACCUMULATIONS COULD OCCUR
QUICKER AND EARLIER THAN ADVERTISED DESPITE THE WARM ROAD SFC
TEMPS OF THE PAST SEVERAL DAYS. COULD SEE 1-3 INCHES OF SOLID
ACCUMULATION THIS AFTN ONCE THE RAIN CHANGES OVER TO SNOW AND
INTENSITY IS MOD-HVY. WILL STILL LOOK FOR TEMPS TO FALL THRU THE
DAY TDA AND TNGT AS THE UPR TROF CONTINUES TO DIG OVER THE DAKOTAS
AND SFC WINDS SHIFT TO NW-N. GOING INTO TNGT...AT LEAST ONE HVY
BAND OF SNOW IS EXPECTED TO DEVELOP FROM NRN IA INTO SRN AND SE
MN...WITH STRONG FGEN OVER THIS SAME AREA LASTING THROUGH
DAYBREAK ON THU. BUFKIT SOUNDINGS STILL SHOW SOLID SUBFREEZING
SOUNDINGS WITH MOD-HVY SNOW ALONG A MANKATO-MINNEAPOLIS-BARRON
LINE WHERE 6-9 INCHES OF ACCUMULATION IS CERTAINLY WITHIN REASON
IN THIS FORECAST. GOING FURTHER E AND W...ACCUMULATIONS DROP OFF
IN A RATHER TIGHT GRADIENT...SUCH THAT NWRN PORTIONS OF THE MPX
CWFA MAY NOT EVEN SEE 1 INCH. THAT SAID...WPC GUIDANCE STILL PINS
A 8-10 INCH SWATH OF SNOWFALL OVER S-CENTRAL MN INTO E-CENTRAL MN
AND W-CENTRAL WI...AND WITH QPF NEARING AN INCH...EVEN SNOWFALL
RATIOS IN THE 4 OR 5 TO 1 AREA PRODUCE A STORM TOTAL OF 4-7
INCHES THRU TNGT WITH SLIGHT ADDITIONS FOR THU. NORMALLY THE
WARMER GROUND WOULD BE ABLE TO MELT THE SNOW AS IT FALLS...AND THE
WET NATURE OF THE SNOW WOULD ALSO HINDER ACCUMULATIONS. HOWEVER...
THE STRONG FGEN WITH HIGH SNOWFALL RATES FOR SEEM TO COMBAT THAT
THINKING IN THIS CASE...LEANING MORE TWD AGREEMENT WITH THE WPC
OUTPUT.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 441 AM CDT WED MAY 1 2013
MODEL AGREEMENT THIS PERIOD REMAINS HIGH THROUGH FRIDAY...BUT
QUICKLY DISAPPEARS FROM FRIDAY NIGHT ONWARDS WITH HOW EACH MODEL
HANDLES THE PROGRESSION OF WHAT WILL BE A CUT OFF LOW THAT SETS UP
NEAR KANSAS CITY BY SATURDAY MORNING. ABOUT THE ONLY THING THERE IS
AGREEMENT ON BEYOND FRIDAY IS THAT HEIGHTS WILL SLOWLY MODIFY FROM
THE WEEKEND INTO NEXT WEEK...WHICH WILL ALLOW HIGHS TO WORK BACK
CLOSER TO EARLY MAY NORMALS.
FOR THURSDAY...FGEN INDUCED BAND OF HEAVY PRECIPITATION WILL
SLOWLY MOVE INTO WRN WI THU MORNING...AND LOOKS TO SPEND MOST OF
THE DAY CONFINED TO AREAS EAST OF AN ALBERT LEA TO RUSH CITY LINE.
GIVEN EXPECTED PERSISTENT PRECIPITATION AND CLOUD COVER...NUDGED
HIGHS DOWN INTO THE MID 30S FOR THURSDAY ACROSS ERN AREAS...WHICH
IS ABOUT 30 DEGREES BELOW NORMAL. OF COURSE THE OTHER IMPACT OF
THE COOLER TEMPS FOR THURSDAY IS THIS MAY ALLOW SNOW TO BE THE
PREDOMINATE P-TYPE FROM WED NIGHT RIGHT THROUGH THE DAY ON
THURSDAY. THE ONLY THING THAT HAS REALLY CHANGED IS A WESTWARD
SHIFT IN THE WARM NOSE BETWEEN H8 AND H7. THE GFS IN PARTICULAR
BRINGS THIS OUT TO ABOUT AN EAU CLAIRE TO LADYSMITH LINE...WITH A
PRETTY SHARP GRADIENT IN POTENTIAL SNOW TOTALS RESULTING ACROSS
THE ERN CWA...WITH VERY LITTLE ACCUMS AT AUGUSTA...WHILE A
MENOMONIE WOULD HAVE THE POTENTIAL FOR AROUND 8 INCHES. GIVEN THE
COOLER TEMPERATURES FOR THURSDAY AND THE POTENTIAL FOR CONTINUED
SNOW ACCUMS THROUGH THE DAY...WE DECIDED TO CARRY WINTER HEADLINES
THROUGH 00Z /7 PM THU/. AS WITH THE SHORT TERM...SNOW TOTALS ARE
TRICKY HERE AS GIVEN THE RATHER HIGH QPF NUMBERS...EVEN
POTENTIALLY UNREALISTIC SNOW RATIOS OF 4-6:1 STILL YIELD SNOWFALL
AMOUNTS THAT ARE OFF INTO UNCHARTED TERRITORY FOR MAY SNOWFALLS IN
THIS AREA. CURRENT GRIDS HAVE ABOUT A 100 MILE WIDE SWATH OF 6-9
INCHES OF SNOW THAT IS CENTERED ALONG A BLUE EARTH /CITY/...TO
HASTINGS...TO CUMBERLAND...WI LINE.
THOUGH CERTAINLY THE WARM SOILS/PAVEMENT TEMPS FROM THE RECENT
WARM SPELL WILL HAVE THE POTENTIAL TO LIMIT ACCUMULATIONS...
EXPECTED SNOWFALL RATES FROM TONIGHT INTO AT LEAST THURSDAY
MORNING IN THE 1-2 INCH PLUS RANGE WILL BE MORE THAN ENOUGH TO
ACCUMULATE ON ANY SURFACE WHILE THOSE TYPES OF RATES ARE BEING
OBSERVED. THERE IS CERTAINLY POTENTIAL FOR SNOWFALL AMOUNTS TO GO
EITHER WAY /HIGHER OR LOWER/ WITH THIS SYSTEM...BUT IF THE CURRENT
FORECAST DOES PAN OUT...THIS STORM WILL CERTAINLY BE RE- WRITING
THE RECORD BOOKS FOR MAY SNOWFALL ACROSS SOUTHERN MN AND WRN WI.
FOR THURSDAY NIGHT INTO FRIDAY...THE FOCUS FOR THE HEAVY
PRECIPITATION SHIFTS EAST FROM ERN IA INTO CENTRAL WI AS LLJ
SLOWLY SHIFTS EAST. AS RESULT...HAVE CUT BACK ON POPS IN THIS
PERIOD... ESPECIALLY ACROSS MN...WITH MUCH OF THE AREA LIKELY
SEEING A BIT OF A REPRIEVE FROM THE PRECIPITATION. IN
ADDITION...WRN MN WILL LIKELY SEE SOME FILTERED SUNSHINE...WHICH
WILL ALLOW WRN AREAS TO WARM BACK TOWARD THE 50S.
FOR FRIDAY NIGHT...MODEL DISAGREEMENTS START TO INCREASE
DRAMATICALLY WITH HANDLING OF A SURGE OF WAA ADVECTIVE PRECIP THAT
WILL BE COMING IN FROM THE SE AS A STRONG VORT MAX ROTATES
AROUND THE MAIN UPPER LOW OVER NRN MO /OFF THE NAM ANYWAYS/. THE
NAM IS THE MIDDLE MEMBER WITH THIS FEATURE...BRINGING ANOTHER
SHIELD OF HEAVY PRECIPITATION ACROSS THE MPX CWA FRIDAY NIGHT INTO
SATURDAY MORNING. THE GFS HAS A SIMILAR FEATURE...BUT KEEPS THE
BRUNT OF THE PRECIPITATION DOWN ACROSS IA. THE ECMWF HAS A
COMPLETELY DIFFERENT IDEA WITH HOW THIS UPPER LOW WILL EVOLVE.
WHERE THE GFS ON SAT HAS THE UPPER LOW OVER NRN ARK...THE NAM OVER
NRN MO...THE 01.00 ECMWF HAS THE SAME...MUCH SHALLOWER LOW UP NEAR
THE MN/DAKOTAS BORDER! GIVEN THE DISAGREEMENTS...HELD POPS TO NO
HIGHER THAN LIKELY ON SATURDAY AS IT COULD RANGE FROM ANYWHERE
BETWEEN A WASHOUT TO JUST COOL AND CLOUDY. AT THE VERY LEAST...AT
LEAST THIS POTENTIAL WAVE OF PRECIPITATION LOOKS TO BE WARM ENOUGH
TO KEEP EVERYTHING LIQUID.
GOING INTO NEXT WORK WEEK...BOTH THE GFS AND THE ECMWF SHOW
ANOTHER OMEGA BLOCK DEVELOPING...ONLY THIS TIME ACROSS THE WRN
US. THE ECMWF IS THE FARTHEST WEST WITH THIS FEATURE...WHICH
ALLOWS IT TO SEND ANOTHER STRONG SHORTWAVE AND COLD FRONT THROUGH
THE MPX AREA MONDAY NIGHT INTO TUESDAY. THE GFS HAS THE BLOCK
FARTHER EAST AND WOULD KEEP THE REGION DRY. AT THIS POINT...KEPT
THE MAINLY CHANCE POPS THAT WERE IN PLACE DURING THIS TIME FRAME.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 119 PM CDT WED MAY 1 2013
PESKY BAND OF RAIN AND SNOW STILL EXTENDS FROM JUST WEST OF RNH TO
MSP AND SOUTHEAST OF RWF. THINK A DIMINISHING TREND WILL CONTINUE
DURING THE AFTERNOON BEFORE THE NEXT ROUND BEGINS TO PUSH IN FROM
THE SOUTHWEST. THE NEXT ROUND THIS EVENING WILL BE MAINLY
SNOW...EXCEPT TOWARD EAU WHERE IT WILL REMAIN A MIX INTO THE
OVERNIGHT. COULD SEE BANDS OF HEAVY SNOW FROM MKT TO MSP AND
NORTHEAST AROUND MIDNIGHT...BEFORE THE PRECIP BEGINS TO INCH
EASTWARD INTO THURSDAY MORNING. RWF/STC/AXN SHOULD MISS OUT ON
PRECIPITATION FOR THE REST OF THE PERIOD WITH VFR CONDITIONS
EXPECTED.
KMSP...MAIN FORECAST CONCERN IS HOW MUCH SNOW STICKS TO PAVEMENT
TONIGHT. LOOKING AT A PERIOD OF HEAVY SNOW POTENTIALLY LATE THIS
EVENING AND OVERNIGHT WHILE TEMPERATURES HOVER NEAR FREEZING. THIS
COULD BE SUFFICIENT TO GET ACCUMULATING SNOW.
/OUTLOOK FOR KMSP/
FRI...MVFR CIGS/VSBYS POSSIBLE WITH CHC -RA/-SN. NE WINDS 10-15
KT.
SAT...MVFR CIGS/VSBYS POSSIBLE WITH CHC -RA. ENE WINDS 5 KT.
SUN...MVFR CIGS/VSBYS POSSIBLE WITH CHC -RA. LGT/VRBL WINDS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WINTER STORM WARNING UNTIL 7 PM CDT THURSDAY FOR MNZ053-060>063-
067>070-074>078-082>085-091>093.
WINTER WEATHER ADVISORY UNTIL 7 PM CDT THURSDAY FOR MNZ044-045-
051-052-058-059-065-066-073.
WI...WINTER STORM WARNING UNTIL 7 PM CDT THURSDAY FOR WIZ014>016-
023>025.
WINTER WEATHER ADVISORY UNTIL 7 PM CDT THURSDAY FOR WIZ026>028.
&&
$$
SHORT TERM...JPC
LONG TERM...MPG
AVIATION...BORGHOFF
AREA FORECAST DISCUSSION
NWS DULUTH MN
1227 PM CDT WED MAY 1 2013
.AVIATION.../18Z TAF ISSUANCE/
A STORM SYSTEM WILL BRING WINTRY WEATHER LATER TODAY AND INTO
TOMORROW MORNING FOR NW WISCONSIN AND SOME PARTS OF FAR EASTERN
MINNESOTA...INCLUDING KDLH. RAIN ACROSS NW WISCONSIN THIS
AFTERNOON WILL TRANSITION TO SNOW BY THIS EVENING AND THEN
CONTINUE THROUGH TOMORROW MORNING. MOST OF THE PRECIPITATION WILL
BE CONFINED TO NW WISCONSIN...BUT SOME LIGHT SNOW MAY MOVE INTO
THE KDLH AREA. EXPECT A PROLONGED PERIOD OF LIFR/IFR CONDITIONS AT
KHYR DUE TO THE LOW CIGS AND REDUCED VSBY FROM THE SNOW. I THINK
KDLH WILL NOT BE QUITE AS AFFECTED...BUT THERE SHOULD BE PERIODS
OF MVFR CIGS AND/OR VSBYS.
THE REST OF NE MINNESOTA SHOULD BE UNAFFECTED BY THE STORM SYSTEM.
THERE WILL BE PERIODS OF MVFR CIGS AT KHIB AND KDLH DUE TO
LINGERING LOW CIGS IN THE NW WINDS. I AM NOT CONFIDENT ENOUGH THAT
THESE CLOUDS WILL CONTINUE BEYOND THIS AFTERNOON TO MAINTAIN THE
MVFR THROUGH THIS EVENING...BUT THE LOW CIGS COULD CONTINUE
OVERNIGHT.
THE WNW WINDS AROUND 10 KNOTS WILL BECOME NNW TONIGHT.
&&
.PREV DISCUSSION... /ISSUED 1055 AM CDT WED MAY 1 2013/
UPDATE...
A NARROW BAND OF RAIN AND SNOW EXTENDED NORTHEAST ACROSS SOUTHERN
PINE COUNTY ACROSS BURNETT...WASHBURN...DOUGLAS AND BAYFIELD
COUNTIES. KRZN HAS RECENTLY WENT TO SNOW...AND A SPOTTER IN
HERBSTER WAS ALSO REPORTING SNOW. THE RAP WAS SHOWING LOWER
WETBULB ZERO VALUES THIS MORNING...BUT HAD THEM INCREASING AGAIN
THIS AFTERNOON. WE THINK THE RAP MAY BE OVERDOING THE INCREASE
THIS AFTERNOON SOME AS THEY RAISE SURFACE TEMPS BACK INTO THE
FORTIES WHICH LOOKS UNLIKELY. SNOWFALL TODAY SHOULD BE LIMITED TO
LESS THAN AN INCH.
THE LATEST NAM STILL SHOWS IMPRESSIVE FGEN TONIGHT...AND WE EXPECT
HEAVY SNOW TO DEVELOP. THE CURRENT HEADLINES BASED ON THE NAM
STILL LOOK GOOD ACROSS WISCONSIN...BUT IT`S LOOKING MORE LIKELY
WE`LL NEED TO UPGRADE IRON COUNTY TO A WARNING. PRICE IS STILL
QUESTIONABLE...BUT THE NORTHERN HALF OF THE COUNTY SHOULD RECEIVE
SOME HEAVY SNOW SO WE MAY HAVE TO UPGRADE THEM AS WELL. WE`LL LOOK
OVER THE LATEST MODELS AND WAIT UNTIL THE AFTERNOON BEFORE MAKING
ANY CHANGES.
WE ALSO MAY HAVE TO INCREASE SNOW TOTALS ACROSS PORTIONS OF
NORTHWEST WISCONSIN GIVEN THE LATEST NAM. WE`LL WAIT FOR THE
GFS/ECMWF BEFORE FINALIZING SNOW TOTALS THIS AFTERNOON. WE
WOULDN`T BE SURPRISED IF SOME THUNDERSNOW DEVELOPS OVERNIGHT...AS
CROSS SECTIONS SHOW IMPRESSIVE FGEN WITH SOME NEGATIVE EPV AND
EVEN LOW CAPE FEEDING INTO NORTHWEST WISCONSIN. CONVECTIVE
SNOWFALL CAN PRODUCE HEAVY SNOW RATES...WITH 2 TO 3 INCHES PER
HOUR POSSIBLE.
PREV DISCUSSION... /ISSUED 430 AM CDT WED MAY 1 2013/
SHORT TERM...TODAY THROUGH THURSDAY.
THINGS ARE COMING TOGETHER FOR A FAIRLY MAJOR EARLY MAY SNOW STORM
ACROSS THE NORTHLAND. THE MODELS CONTINUE TO INDICATE THE
POTENTIAL FOR VERY HEAVY SNOW ACCUMULATION TONIGHT AND THURSDAY
ACROSS NORTHWESTERN WISCONSIN. THE MODELS DIFFER TO SOME EXTENT ON
THE SNOW POTENTIAL ON THE MINNESOTA SIDE...AND ALSO IN THE HURLEY
AND PARK FALLS AREAS. HAVE UPGRADED THE WATCH FOR MOST OF
NORTHWESTERN WISCONSIN TO A WARNING...BUT WILL KEEP IRON AND PRICE
COUNTIES IN A WATCH FOR NOW. ON THE MINNESOTA SIDE...HAVE ISSUED A
WINTER WEATHER ADVISORY FOR SNOW FROM PINE COUNTY...TOWARD DULUTH
AND INTO THE ARROWHEAD.
THE MAJORITY OF THE MODEL SOLUTIONS PAINT ANYWHERE FROM 6 TO 12
INCHES OF TOTAL SNOW ACCUMULATION ACROSS MUCH OF NORTHWESTERN
WISCONSIN. THE SREF PLUMES SHOW A WIDE SPREAD OF POSSIBLE TOTAL
SNOWFALL...WITH AMOUNTS RANGING FROM LESS THAN AN INCH TO AS MUCH
AS 19 INCHES. THE MAJORITY OF THE VALUES LIE SOMEWHERE NEAR THE
MEAN...WHICH IS AROUND 11 INCHES AT KHYR. THE MEAN AT SIREN WI IS
CLOSE TO 8 INCHES...WITH A LITTLE OVER 10 INCHES AT ASHLAND.
FURTHER WEST...THERE IS A LOT MORE QUESTION ACROSS THE MN SIDE.
THE MEAN FROM THE PLUMES FOR DULUTH IS BETWEEN 3 AND 4 INCHES BUT
WITH A HUGE MODEL SPREAD. WE ARE FAIRLY CONFIDENT THAT A BAND OF
VERY HEAVY SNOW WILL SET UP ACROSS MUCH OF NW WI...BUT AMOUNTS
FURTHER WEST ARE STILL TRICKY DUE TO THE SHARP GRADIENT IN
SNOWFALL EXPECTED. FOR EXAMPLE...THE NAM AND THE GFS BRING VERY
LITTLE SNOW ACCUMULATION TO DULUTH...WHILE THE ECMWF BRINGS A GOOD
4 TO 6 INCHES.
FOR TODAY...WILL START WITH LIGHT RAIN ACROSS THE REGION...AS IT
SPREADS QUICKLY IN FROM THE SOUTHWEST. TEMPS WILL START OUT IN THE
30S NORTHWEST AND 50S SOUTHEAST. TEMPS WILL BEGIN TO FALL DURING
THE DAY...RESULTING IN A MIXING WITH SNOW. THE PRECIPITATION
SHOULD LARGELY BECOME ALL SNOW TONIGHT...WITH SNOWFALL RATES OF
MORE THAN AN INCH AN HOUR AT TIMES...ESPECIALLY IN THE WARNING
AREA.
THE SNOW WILL THEN BEGIN TO MIX WITH RAIN AS IT DIMINISHES BY
THURSDAY AFTERNOON. IN ALL WE THINK 6 TO 12 IN NW WI...AND 2 TO 4
OR 3 TO 6 IN ADJACENT AREAS OF NE MN.
LONG TERM...THURSDAY NIGHT THROUGH TUESDAY...
QUITE A BIT OF UNCERTAINTY THROUGHOUT THE LONG TERM PERIODS..
BEGINNING WITH HANDLING OF UPPER LOW THAT WILL DEVELOP OVER THE
CENTRAL U.S. OVER THE NEXT 36 HOURS. THERE IS STILL FAIRLY WIDE
RANGING DIVERGENCE IN THE MODEL GUIDANCE..WITH SEVERAL RUNS TAKING
THE LOW MORE EAST INTO THE OHIO VALLEY/LOWER GRT LAKES..WITH THE
ECMWF STILL BEING THE LONE MODEL OUT IN LIFTING THE LOW NWD ACROSS
MN FRIDAY-SATURDAY. IF THE ECM SOLUTION COMES TO BEAR..WE WILL
LIKELY HAVE A LONGER DURATION RAIN/SNOW EVENT OVER MUCH OF THE CWA
TO DEAL WITH EVEN AFTER THE HEAVY SNOWS OVER NW WISCONSIN IN THE
IMMEDIATE SHORT TERM.
SIMILAR STORY FOR HANDLING OF THE FLOW PATTERN AND FORCING FOR THE
SUNDAY-TUESDAY TIME FRAME..WITH EVEN MORE SPREAD IN THE VARIOUS
DETERMINISTIC AND ENSEMBLE SOLUTIONS. SOME HAVE A VERY BLOCKED/CUT
OFF PATTERN, WHILE OTHERS TRANSITION TO A MORE WNW PROGRESSIVE NRN
STREAM PATTERN BY TUESDAY.
NEEDLESS TO SAY..CONFIDENCE IN ANY DETAILS WHATSOEVER IS VERY LOW
RIGHT NOW FOR THE ENTIRE DAY 2-7 TIME PERIOD. GIVEN THIS..WE HAVE
OPTED TO KEEP A MENTION OF AT LEAST SOME CHANCES FOR PRECIP IN MOST
PERIODS..ALONG WITH TEMPS AT OR SLIGHTLY BELOW SEASONAL NORMS.
HYDROLOGY...
RIVERS LEVELS CONTINUE TO RISE..ALTHOUGH AT A SLOWER RATE THAN THE
PAST FEW DAYS ACROSS THE SOUTHERN PARTS OF THE CWA AS MOST SNOW HAS
MELTED AND IN MOVING WITHIN THE DRAINAGE SYSTEM. FLOOD WARNINGS ARE
IN EFFECT ALONG THE MISSISSIPPI RIVER AT AITKIN AND FORT RIPLEY AND
ALONG THE ST. LOUIS RIVER AT SCANLON FOR MINOR FLOODING. THERE ARE
ALSO AREAL FLOOD ADVISORIES ACROSS PARTS OF THE NORTHLAND DUE TO
SOME REPORTS OF FLOODING...INCLUDING ALONG AND OVER SOME ROADWAYS.
OF PARTICULAR CONCERN THE NEXT 48-60 HOURS IS VERY RAPID MELT/RUNOFF
AND AREAL/RIVER FLOODING ACROSS THE GOGEBIC RANGE AREA OF NORTHWEST
WISCONSIN. THE BAD RIVER CONTINUES TO RISE AS WELL...AND WE MAY BE
UPGRADING TO WARNING THERE AS WELL BUT ARE WAITING FOR SOME MORE
INFORMATION BEFORE DOING SO.
PRECIPITATION WILL OVERSPREAD NW WISCONSIN AND FAR EASTERN MINNESOTA
TODAY...AND IT WILL LIKELY CONTINUE THROUGH AT LEAST THURSDAY..
INITIALLY IN THE FORM OF RAIN..BUT TRANSITIONING TO SNOW LATE THIS
AFTERNOON AND TONIGHT. MUCH OF NORTHWEST WISCONSIN WILL LIKELY GET
AT LEAST A HALF INCH OF QPF THROUGH THURSDAY...WITH SOME
INDICATIONS OF OVER AN INCH. ALTHOUGH HEAVY WET SNOW IS EXPECTED
TONIGHT INTO THURSDAY...THIS PRECIPITATION WILL EVENTUALLY IMPACT
THE RIVER AND STREAMS. THE PRECIPITATION IS NOT EXPECTED TO HAVE
LARGE IMPACTS IMMEDIATELY TO FLOODING CONCERNS...BUT IT WILL
LIKELY RESULT IN ADDITIONAL RISES ALONG SOME STREAMS AND RIVERS
LATER THIS WEEK INTO THE WEEKEND.
&&
.POINT TEMPS/POPS...
DLH 31 43 32 39 / 70 70 20 40
INL 27 43 28 48 / 10 10 10 20
BRD 28 46 32 48 / 10 10 10 30
HYR 31 37 30 39 / 100 100 50 60
ASX 30 35 30 36 / 100 100 50 60
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 7 PM CDT
THURSDAY FOR MNZ012-020-021-037-038.
WI...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 PM CDT THURSDAY
FOR WIZ001>003-006>008.
WINTER STORM WATCH FROM 7 PM CDT THIS EVENING THROUGH THURSDAY
EVENING FOR WIZ004-009.
LS...NONE.
&&
$$
SHORT TERM...MELDE
AVIATION...GROCHOCINSKI
AREA FORECAST DISCUSSION
NWS RALEIGH NC
312 PM EDT WED MAY 1 2013
.SYNOPSIS...
HIGH PRESSURE WILL EXTEND DOWN THE EAST COAST THROUGH THE REMAINDER
OF THE WORK WEEK. LOW LEVEL NE FLOW WILL MAINTAIN A MOIST AIR MASS
THROUGH EARLY THURSDAY...AFTERWHICH DRIER AIR WILL OVERSPREAD THE
REGION.
&&
.NEAR TERM /TONIGHT/...
AS OF 312 PM WEDNESDAY...
TONIGHT...925-850MB FLOW VEERS THIS EVENING TO MORE OF A E-SE
DIRECTION. THIS UPSLOPE COMPONENT AND FETCH OFF THE ATLANTIC WILL
MAINTAIN LOW OVERCAST SKIES. ISENTROPIC LIFT IN THE 290-295K LAYER
SHOULD RESULT IN AREAS OF DRIZZLE AND POSSIBLY SOME POCKETS OF LIGHT
RAIN. GFS DEPICTS A DECENT POCKET OF LIFT OVER THE WESTERN PIEDMONT
LATE TONIGHT WHICH WOULD SUPPORT A GREATER CHANCE OF RAIN
OVERNIGHT. HRRR VERIFYING RELATIVELY WELL WITH ISOLATED/SCATTERED
SHOWERS ALONG IMMEDIATE COAST AND SPOTS OF LIGHT PRECIP INLAND. THIS
MODEL SUGGEST BULK OF VERY LIGHT PRECIP DEVELOPING OVER THE PIEDMONT
BY 02-05Z. PLAN TO MAINTAIN MEASURABLE POPS AT 20 PERCENT THOUGH
EXPECT AREAS OF DRIZZLE TO DEVELOP BY LATE EVENING AND CONTINUE INTO
THE OVERNIGHT. MIN TEMPS MID-UPPER 50S. ANY FOG THAT DEVELOPS WILL
BE SPOTTY AS STEADY NE SFC WIND WILL KEEP AIR MASS MIXED.
&&
.SHORT TERM /THURSDAY AND THURSDAY NIGHT/...
AS OF 312 PM WEDNESDAY...
THURSDAY...CONSIDERABLE CLOUDINESS IN THE MORNING WILL GRADUALLY
BECOME MOSTLY SUNNY/PARTLY CLOUDY ACROSS THE REGION AS AS LOW LEVEL
HIGH PRESSURE DRIFTS SOUTHWEST INTO THE NORTHERN MID ATLANTIC. THE
CLOSER PROXIMITY OF THIS FEATURE TO OUR REGION PLUS ADVECTION OF
DRIER AIR WILL AID TO SLOWLY ERODE THE CLOUD COVER FROM THE EAST
LATE THU AM THROUGH THE AFTERNOON. THE WESTERN-SOUTHERN PIEDMONT
WILL BE THE LAST TO EXPERIENCE PARTIAL CLEARING. BASED ON THIS SKY
TREND...EXPECT WARMER TEMPS EAST VERSUS WEST. MAX TEMPS LOWER 70S
FAR SOUTH-SE TO UPPER 60S W-NW.
THURSDAY NIGHT..RIDGE AT THE SURFACE AND ALOFT WILL RESULT IN FAIR
SKIES. RESIDUAL LOW LEVEL MOISTURE SHOULD ALLOW PATCHES OF FOG TO
DEVELOP. IF SFC WINDS ABLE TO DECOUPLE...MAY SEE WIDESPREAD FOG WITH
POCKETS OF DENSE FOG. COOLER OVERNIGHT TEMPS IN THE UPPER 40S TO THE
LOWER 50S.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
AS OF 250 PM WEDNESDAY...
FRIDAY THROUGH SUNDAY:
MEDIUM RANGE MODELS CONTINUE TO INDICATE AN AMPLIFIED PATTERN FOR
THE START OF THE PERIOD (LATE WEEK INTO THE WEEKEND)... WITH HIGH
PRESSURE ALOFT CENTERED JUST TO THE NORTH OF THE AREA AND SURFACE
HIGH PRESSURE LOCATED TO THE NORTHEAST OF THE REGION WITH CLOSED
LOWS FLANKING THE RIDGE ALOFT TO THE WEST AND EAST (ACROSS THE
CENTRAL CONUS AND WESTERN ATLANTIC). THIS WILL KEEP CENTRAL NC IN
THE CURRENT PATTERN OF A COOL EAST TO NORTHEASTERLY LOW LEVEL
FLOW... WITH PERIODS OF LOW CLOUDS AND POSSIBLE DRIZZLE. HOWEVER...
THINK WE WILL SEE AT LEAST SOME BREAKS IN THE CLOUDS OVER THE
WEEKEND. THUS... EXPECT HIGH TEMPS WILL GENERALLY BE BELOW NORMAL
RANGING FROM THE UPPER 60S TO THE 70S... WITH MORNING LOWS EXPECTED
TO BE NEAR NORMAL. THE COOLEST TEMPS ARE EXPECTED FRIDAY NIGHT INTO
SATURDAY WHEN IT APPEARS ANOTHER REINFORCING SURGE OF MOISTURE AND
COOLER TEMPS WILL FILTER INTO THE REGION... ASSOCIATED WITH ANOTHER
DISTURBANCE MOVING THROUGH THE CYCLONIC FLOW AROUND THE WESTERN
ATLANTIC LOW.
SUNDAY NIGHT THROUGH WEDNESDAY:
CONFIDENCE IN THE FORECAST PAST THE UPCOMING WEEKEND GOES DOWN
SIGNIFICANTLY... AS THE MEDIUM RANGE MODEL GUIDANCE IS STRUGGLING
WITH THE EVENTUAL PROGRESSION AND EVOLUTION OF THE CENTRAL CONUS
CLOSED LOW. HAVE STUCK CLOSE TO THE PREVIOUS FORECAST AND WPC AT
THIS TIME... WITH WPC GOING GENERALLY WITH THE 00Z/01ST ECENS MEAN
AS A SYNOPTIC GUIDE. WPC ALSO NOTED THE GFS/GEFS MEANS ARE
INCREASING OUTLIERS TO EVEN THE GEM GLOBAL AND UKMET (WHICH
YESTERDAY WERE MORE CORRELATED WITH THE GFS). NONETHELESS... IT
STILL LOOKS LIKE WE MAY SEE CHANCES FOR SHOWERS INCREASE NEXT WEEK
AS THE RIDGE BEGINS TO BREAK DOWN SOME/SHIFT MORE TO THE EAST OF THE
AREA. THUS... WILL ADVERTISE LOW END CHANCE POPS/SLIGHT CHANCE POPS
ACROSS THE AREA FOR EARLY NEXT WEEK... WITH SLOWLY MODERATING TEMPS.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 140 PM WEDNESDAY...
A RELATIVELY MOIST NE FLOW OFF THE ATLANTIC WILL MAINTAIN A STRATUS
DECK WITH MVFR CEILINGS ACROSS MOST OF CENTRAL NC THIS AFTERNOON
THROUGH EARLY EVENING. THE EXCEPTION MAY BE IN VICINITY OF KFAY AND
KRWI WHERE THE CLOUD DECK MAY SCATTER INTO THE LOW END VFR FOR A FEW
HOURS LATE THIS AFTERNOON-EARLY EVENING. A STEADY NE WIND 9-14KTS
WITH GUSTS 17-22KTS WILL BE COMMON.
ANY CLEARING THAT OCCURS EARLY THIS EVENING WILL QUICKLY FILL IN
WITH LOW CLOUDS AND ASSOCIATED IFR/LOW END MVFR CEILINGS. MAY ALSO
SEE POCKETS OF MVFR VISIBILITY DUE TO FOG AND/OR DRIZZLE OVERNIGHT
INTO EARLY THU...MAINLY ACROSS THE PIEDMONT.
THURSDAY...LOW CLOUDS EARLY IN THE DAY MAY LIFT/DISSIPATE INTO A
FEW/SCATTERED STRATOCU DECK WITH BASES 2500-3500FT. MAINLY VFR
CONDITIONS EXPECTED THU EVENING THEN WIDESPREAD MVFR/IFR VISIBILITY
IN FOG IS ANTICIPATED.
FOR FRIDAY THROUGH MONDAY...HIGH PRESSURE OVER THE REGION SHOULD
PROVIDE PROLONGED PERIODS OF VFR CONDITIONS. EXCEPTIONS WILL BE
DURING THE LATE NIGHT/EARLY MORNING HOURS WHEN A 4-6 HOUR PERIOD OF
MVFR/IFR CEILINGS AND FOG ARE PROBABLE.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM...WSS
SHORT TERM...WSS
LONG TERM...BSD
AVIATION...WSS
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
250 PM EDT WED MAY 1 2013
.SYNOPSIS...
HIGH PRESSURE RIDGING INTO THE CAROLINAS FROM THE NORTH WILL KEEP
PLEASANT BUT COOL WEATHER IN PLACE MUCH OF THE WEEK INTO THE
WEEKEND. A COLD FRONT MAY APPROACH THE REGION WITH MORE UNSETTLED
WEATHER EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
AS OF 2:10 PM WEDNESDAY...LATEST RADAR AND SATELLITE LOOPS AND
SURFACE OBS REVEAL THAT AN EXTENSIVE LAYER OF STRATO-CU CONTINUES
TO BLANKET THE AREA AS SOME LIGHT SHOWERS OR PATCHES OF DRIZZLE
APPROACH THE CAPE FEAR REGION FROM JUST OFFSHORE. THE BIGGER
PICTURE HAS A STRONG SURFACE RIDGE EXTENDING SW ALONG THE
APPALACHIANS AS A SURFACE TROUGH EXTENDS JUST OFFSHORE.
EXTENSIVE CLOUDINESS WILL CONTINUE THROUGH THE NEAR TERM AS A
RELATIVELY COOL AND MOIST EASTERLY LOW LEVEL FLOW CONTINUES ACROSS
THE FORECAST AREA. MODEST COLD ADVECTION AND EXTENSIVE CLOUD COVER
WILL KEEP AFTERNOON TEMPERATURES GENERALLY BELOW NORMAL...ALTHOUGH
ANY BREAKS IN THE CLOUD COVER COULD ALLOW TEMPERATURES TO SPIKE
INTO THE MID 70S. OTHERWISE...MOST PLACES WILL SEE UPPER 60S TO
AROUND 70 FOR THE REMAINDER OF THE AFTERNOON.
CHANCES FOR PRECIPITATION WILL INCREASE MODESTLY THIS AFTERNOON
AND EVENING AS THE SURFACE TROUGH OVER THE COASTAL WATERS MOVES
ASHORE. P/W VALUES WILL PEAK AT OVER AN INCH TONIGHT AS MOISTURE
FLUX INCREASES. HAVE MADE NO SUBSTANTIAL CHANGES TO PRECIPITATION
CHANCES FOR THE REMAINDER OF THE NEAR TERM FROM THE PREVIOUS
FORECAST PACKAGES. STILL EXPECT ISOLATED SHOWERS THIS AFTERNOON
AND EVENING...WITH THE SLIGHT CHANCE FOR RAIN OVERNIGHT...AND QPF
VALUES ON THE ORDER OF A FEW HUNDREDTHS OF AN INCH.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
AS OF 3 PM WEDNESDAY...THE FORECAST AREA WILL CONTINUE TO BE ENTANGLED IN A
BLOCKING/OMEGA PATTERN ALOFT. MID LEVEL LOW PRESSURE/TROUGHS WILL BE
SITUATED ACROSS THE MISSISSIPPI VALLEY AND THE WESTERN ATLANTIC WITH
HIGH PRESSURE AXIS OVER THE UPPER GREAT LAKES REGION EXTENDING
SOUTH. AT THE SURFACE...HIGH PRESSURE WILL REMAIN ALIGNED JUST UNDER
THE UPPER RIDGE AXIS. LOW CLOUDS AND COOL TEMPERATURES WILL PREVAIL
THURSDAY WITH CONDITIONS A BIT DRIER FRIDAY. SOUNDINGS SHOW MOISTURE
DECREASES APPRECIABLY FRIDAY ALLOWING A BETTER CHANCE FOR DEEPER
MIXING. REGARDING TEMPERATURES...GUIDANCE IS IN GENERALLY GOOD
AGREEMENT WITH THE PERSISTENT LOW LEVEL FLOW KEEPING THE BOUNDARY
LAYER MIXED OVERNIGHT...AND IT IS THESE PERIODS WHERE I
DEVIATED...WARMER...AWAY FROM GUIDANCE.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 3 PM WEDNESDAY...A RATHER MUDDLED FORECAST AS THE CAROLINAS
WILL BE UNDERNEATH THE RIDGE PORTION OF AN OMEGA BLOCK THAT MAY OR
MAY NOT BE CLOSING OFF. THAT IS...THE WESTERN CUTOFF WILL BE TRYING
TO PROGRESS EASTWARD UNDER THE RIDGE AND IMPINGE UPON THE REGION
FROM THE WEST. MODEL SOLUTIONS HAVE VARIED WILDLY AND THE BEST
COURSE OF ACTION AT THIS POINT SEEMS TO BE TO MINIMIZE CHANGES
ESPECIALLY SINCE PREVIOUS FORECAST ITERATIONS HAVE INCORPORATED
MODEL BIAS AND FAVORED CLIMATOLOGICALLY LIKELY PATTERN EVOLUTION.
THAT SAID...GUIDANCE SUCH AS THE GFS WHICH AGGRESSIVELY BRING THE
WESTERN CUTOFF INTO THE REGION BY EARLY NEXT WEEK APPEAR LEAST
LIKELY. THE EC SPLITS THE TROUGH AND HAS THE SOUTHERN FEATURE
CUTTING BENEATH THE RIDGE NOW ALBEIT IN A MUCH WEAKENED STATE AND
ALSO WELL SUPPRESSED TO THE SOUTH BY THE STALWART RIDGE...SO MUCH SO
THAT IT MAY BE HARD PRESSED TO GENERATE WEATHER LOCALLY SAVE FOR
PERHAPS FAR SRN ZONES. MEANWHILE THE REMAINING ENERGY IS FORCED TO
RIDE UP OVER THE RIDGE AND GETS SHUNTED INTO CANADA. DOWNSTREAM FROM
ALL OF THIS ACTION WILL BE THE WEST ATLANTIC RIDGE...THE DEGREE OF
ITS AMPLIFICATION AFFECTED BY ALL ALREADY DISCUSSED. SINCE THIS WILL
BE THE FEATURE AIDING IN PUSHING HIGHER PRESSURES/SLIGHTLY COOLER
AIR INTO THE CAROLINAS IT TOO WILL BE A PLAYER IN THE
FORECAST...MAINLY DICTATING HOW MUCH COOLER THAN CLIMO AFTERNOONS
END UP OVER THE WEEKEND. THE WEAKENING OF BOTH UPPER LOWS LATER IN
THE PERIOD SHOULD ALLOW TEMPS TO CREEP UP BACK TOWARDS CLIMO. RAIN
CHANCES ARGUABLY MAY INCREASE LATE IN THE PERIOD BUT OVERALL WILL
STILL REMAIN QUITE LOW.
&&
.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
AS OF 18Z...VISIBLE SATELLITE IMAGERY SHOWS AN EXTENSIVE STRATOCU
DECK ACROSS THE CWA...THOUGH CIGS AT MOST TERMS HAVE NOW LIFTED TO
VFR LEVELS. LOW CLOUDS WILL LIKELY PERSIST THRU THE PERIOD WITH HIGH
PRESSURE WEDGED INTO THE CAROLINAS. HAVE INCLUDED VCSH FOR KILM
BASED ON RADAR TRENDS AND LATEST HRRR OUTPUT. EXPECT VFR CIGS TO
BECOME MVFR AFTER 00Z WITH IFR STRATUS CERTAINLY POSSIBLE OVERNIGHT
AT ALL TERMS. NORTHEAST WINDS 10-12 KTS WILL WEAKEN SLIGHTLY TONIGHT
BEFORE PICKING BACK UP TO AROUND 10 KTS EARLY THURSDAY. DURING THE
DAY...EXPECT MVFR CIGS WITH E-NE WINDS 10 TO 15 KTS AND GUSTS OF
20-25 KTS.
EXTENDED OUTLOOK...SLIGHT CHANCE OF SHOWERS THURSDAY WITH BREEZY
CONDITIONS THROUGH FRIDAY. OTHERWISE VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 2:10 PM WEDNESDAY...HIGH PRESSURE PRESSING DOWN FROM THE
NORTH WILL MAINTAIN A STEADY NORTHEASTERLY FLOW THOUGH THE NEAR
TERM...WITH WINDS INCREASING TO 15 TO 20 KTS THIS EVENING. SEAS
WILL BUILD INTO THE 4 TO 6 FT RANGE TONIGHT...SO KEEPING PRESENT
SMALL CRAFT ADVISORY IN PLACE FOR TONIGHT WITH NO SUBSTANTIAL
CHANGES.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 PM WEDNESDAY...PERSISTENT NORTHEAST FLOW WILL BE THE STORY
THROUGH THE PERIOD. DIFFICULT TO ACTUALLY NAIL DOWN THE PERIOD WHERE
WINDS WILL BE THE HIGHEST OTHER THAN A GENERAL INCREASE LATE
FRIDAY/EARLY SATURDAY WHEN THE GRADIENT PICKS UP A BIT WITH LOW
PRESSURE DEVELOPING INTO THE TENNESSEE VALLEY. OVERALL EXPECT
HEALTHY 15-20 KNOTS. WAVEWATCH SEAS OF 3-7 FEET LOOK REASONABLE AND
THE SMALL CRAFT ADVISORY CONTINUES FOR ALL WATERS THURSDAY.
LONG TERM /SATURDAY THROUGH MONDAY/...
AS OF 3 PM WEDNESDAY...ON SATURDAY THE COASTAL WATERS WILL SIT
BETWEEN TWO UPPER LEVEL CUTOFF TROUGHS WITH A RIDGE POKED UP BETWEEN
UP THE COASTLINE. THE EASTERN TROUGH WILL HELP DRIVE SURFACE HIGH
PRESSURE DOWN THE EASTERN THIRD OF THE U.S. BRINGING A
NORTHEASTERLY GRADIENT WIND LOCALLY. THE STRENGTH OF THE WIND AND
RESULTING WAVES PAIRED WITH LONG FETCH SWELL ENERGY COULD
NECESSITATE AND ADVISORY. HEADING INTO SUNDAY THE SURFACE FLOW MAY
VEER AND WEAKEN JUST ENOUGH TO DROP FLAGS DOWN TO CAUTIONARY
HEADLINES. ONE CAVEAT BEING THAT THE UPPER LEVEL PATTERN IS ONE THAT
IS OFTEN POORLY HANDLED BY GUIDANCE. SPECIFICALLY IT IS USUALLY
BROKEN DOWN FROM BEING BLOCKED TO PROGRESSIVE TOO QUICKLY. THAT SAID
ADVISORY MAY LAST A BIT LONGER THAN CURRENTLY IMPLIED BY FCST. WITH
A SIMILAR POSSIBILITY OF SLOWER PROGRESSION MONDAY WILL BRING
ADDITIONAL SLIGHT VEERING AND OF WINDS. GUIDANCE SHOWING JUST ENOUGH
SWELL TO PUSH SEAS BACK CLOSE TO SCA/SCEC THRESHOLDS.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 6 PM EDT
THURSDAY FOR AMZ250-252-254-256.
&&
$$
SYNOPSIS...SHK
NEAR TERM...REK
SHORT TERM...SHK
LONG TERM...MBB
AVIATION...BJR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
210 PM EDT WED MAY 1 2013
.SYNOPSIS...
HIGH PRESSURE RIDGING INTO THE CAROLINAS FROM THE NORTH WILL KEEP
PLEASANT BUT COOL WEATHER IN PLACE MUCH OF THE WEEK INTO THE
WEEKEND. A COLD FRONT MAY APPROACH THE REGION WITH MORE UNSETTLED
WEATHER EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 2:10 PM WEDNESDAY...LATEST RADAR AND SATELLITE LOOPS AND
SURFACE OBS REVEAL THAT AN EXTENSIVE LAYER OF STRATO-CU CONTINUES
TO BLANKET THE AREA AS SOME LIGHT SHOWERS OR PATCHES OF DRIZZLE
APPROACH THE CAPE FEAR REGION FROM JUST OFFSHORE. THE BIGGER
PICTURE HAS A STRONG SURFACE RIDGE EXTENDING SW ALONG THE
APPALACHIANS AS A SURFACE TROUGH EXTENDS JUST OFFSHORE.
EXTENSIVE CLOUDINESS WILL CONTINUE THROUGH THE NEAR TERM AS A
RELATIVELY COOL AND MOIST EASTERLY LOW LEVEL FLOW CONTINUES ACROSS
THE FORECAST AREA. MODEST COLD ADVECTION AND EXTENSIVE CLOUD COVER
WILL KEEP AFTERNOON TEMPERATURES GENERALLY BELOW NORMAL...ALTHOUGH
ANY BREAKS IN THE CLOUD COVER COULD ALLOW TEMPERATURES TO SPIKE
INTO THE MID 70S. OTHERWISE...MOST PLACES WILL SEE UPPER 60S TO
AROUND 70 FOR THE REMAINDER OF THE AFTERNOON.
CHANCES FOR PRECIPITATION WILL INCREASE MODESTLY THIS AFTERNOON
AND EVENING AS THE SURFACE TROUGH OVER THE COASTAL WATERS MOVES
ASHORE. P/W VALUES WILL PEAK AT OVER AN INCH TONIGHT AS MOISTURE
FLUX INCREASES. HAVE MADE NO SUBSTANTIAL CHANGES TO PRECIPITATION
CHANCES FOR THE REMAINDER OF THE NEAR TERM FROM THE PREVIOUS
FORECAST PACKAGES. STILL EXPECT ISOLATED SHOWERS THIS AFTERNOON
AND EVENING...WITH THE SLIGHT CHANCE FOR RAIN OVERNIGHT...AND QPF
VALUES ON THE ORDER OF A FEW HUNDREDTHS OF AN INCH.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM WEDNESDAY...HIGHLY AMPLIFIED PATTERN DEVELOPS DURING
THE END OF THE WEEK AS ANOMALOUSLY STRONG 5H RIDGE TRANSITIONS INTO
AN OMEGA-BLOCK TYPE PATTERN INTO FRIDAY. THIS RIDGE IS SANDWICHED
BETWEEN TWO STRONG CLOSED LOWS...ONE ACROSS THE WESTERN
ATLANTIC...AND ONE STALLED OVER THE GREAT PLAINS. A
THIRD...WEAKER...AREA OF LOW PRESSURE IS SQUELCHED SOUTHWARD THROUGH
THE GULF OF MEXICO.
TROUGH OF LOW PRESSURE OFFSHORE THURSDAY WILL GET SHUNTED WELL SOUTH
BY RIDGE ADVANCING FROM THE NE. WHILE ISOLATED SHOWERS WILL REMAIN
POSSIBLE THROUGH THURSDAY WITH DIURNAL HEATING IN A MODESTLY MOIST
ENVIRONMENT AND ONSHORE FLOW...TREND WILL BE FOR A DRYING COLUMN AND
HENCE DECREASING RAIN CHANCES BY THURSDAY NIGHT. AS HIGH MORE
STRONGLY RIDGES DOWN THE COAST ON FRIDAY...COMBINED WITH DEVELOPING
OMEGA BLOCK ALONG THE EASTERN CONUS...FRIDAY WILL BE A DRY DAY WITH
AMPLE SUNSHINE.
EVEN WITH A RIDGE BUILDING ALOFT...COOL NE FLOW WILL KEEP TEMPS
SOMEWHAT BELOW NORMAL FOR EARLY MAY...IN THE LOW 70S MOST SPOTS BOTH
DAYS. WHILE RADIATIONAL COOLING WILL BE MINIMIZED OVERALL BY NE
WINDS...COOL ADVECTION WILL HELP LOWS FALL TO A FEW DEGREES BELOW
NORMAL AS WELL...LOW 50S INLAND...MID 50S AT THE COAST.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 300 AM WEDNESDAY...STILL MUCH UNCERTAINTY IN THE EXTENDED AS
LONG-RANGE GUIDANCE REFUSES TO COOPERATE WITH ONE-ANOTHER. OMEGA
BLOCK IN PLACE AT THE START OF THE PERIOD WILL FUNCTION AS A DAM TO
THE ATMOSPHERIC RIVER...LIMITING ANY SIGNIFICANT CHANGES TO THE
SENSIBLE WEATHER. WITH LARGE RIDGE ALOFT AND SURFACE HIGH RIDGING
DOWN THE COAST...EXPECT QUITE A BIT OF SUNSHINE...BUT NE WINDS WILL
KEEP TEMPS A LITTLE BELOW CLIMO EACH AFTN THROUGH THE WKND. GFS
CONTINUES TO BE MORE AGGRESSIVE BREAKING DOWN THE RIDGE...A KNOWN
BIAS OF THE GUIDANCE...AND WILL FAVOR THE MORE-CONSISTENT ECMWF AND
LOWER POP TO SILENT FOR THE WKND.
MAJOR DIFFERENCES EXIST EARLY WEEK WITH THE BEHAVIOR OF A CLOSED LOW
ACROSS THE GREAT PLAINS AND THE EVOLUTION OF THE OMEGA BLOCK.
ECMWF/CMC/MANY-ENSEMBLES SUPPORT THE CLOSED LOW MOVING WELL NORTH
OVER TOP THE RIDGE THROUGH TUESDAY...WHILE THE GFS SUGGESTS THE LOW
WILL BREAK DOWN THE RIDGE AND MOVE BASICALLY OVERHEAD...AND BY EARLY
NEXT WEEK THE MODELS ARE 180 DEGREES OUT OF PHASE. THE GFS SOLUTION
SEEMS UNLIKELY...AND THUS WILL SHOW A WARMING TREND INTO EARLY NEXT
WEEK. WILL CONTINUE WITH INHERITED SCHC/SILENT POP FOR NEXT WEEK TO
ACCOUNT FOR THE GFS...BUT IT CERTAINLY SEEMS PLAUSIBLE THAT THE
ENTIRETY OF THE EXTENDED WILL BE RAIN-FREE WITH COOL-TO-PLEASANT
MID-SPRING WEATHER.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 18Z...VISIBLE SATELLITE IMAGERY SHOWS AN EXTENSIVE STRATOCU
DECK ACROSS THE CWA...THOUGH CIGS AT MOST TERMS HAVE NOW LIFTED TO
VFR LEVELS. LOW CLOUDS WILL LIKELY PERSIST THRU THE PERIOD WITH HIGH
PRESSURE WEDGED INTO THE CAROLINAS. HAVE INCLUDED VCSH FOR KILM
BASED ON RADAR TRENDS AND LATEST HRRR OUTPUT. EXPECT VFR CIGS TO
BECOME MVFR AFTER 00Z WITH IFR STRATUS CERTAINLY POSSIBLE OVERNIGHT
AT ALL TERMS. NORTHEAST WINDS 10-12 KTS WILL WEAKEN SLIGHTLY TONIGHT
BEFORE PICKING BACK UP TO AROUND 10 KTS EARLY THURSDAY. DURING THE
DAY...EXPECT MVFR CIGS WITH E-NE WINDS 10 TO 15 KTS AND GUSTS OF
20-25 KTS.
EXTENDED OUTLOOK...SLIGHT CHANCE OF SHOWERS THURSDAY WITH BREEZY
CONDITIONS THROUGH FRIDAY. OTHERWISE VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 2:10 PM WEDNESDAY...HIGH PRESSURE PRESSING DOWN FROM THE
NORTH WILL MAINTAIN A STEADY NORTHEASTERLY FLOW THOUGH THE NEAR
TERM...WITH WINDS INCREASING TO 15 TO 20 KTS THIS EVENING. SEAS
WILL BUILD INTO THE 4 TO 6 FT RANGE TONIGHT...SO KEEPING PRESENT
SMALL CRAFT ADVISORY IN PLACE FOR TONIGHT WITH NO SUBSTANTIAL
CHANGES.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3:00 AM WEDNESDAY...HIGH PRESSURE RIDGING DOWN THE EAST
COAST WILL CREATE GUSTY NE WINDS THROUGH THE SHORT TERM...AND A
LONG DURATION SCA...WHICH IS IN EFFECT FOR THURSDAY ATTM...WILL
LIKELY BE NEEDED FOR THE ENTIRETY OF THE PERIOD. WINDS OF 15-25
KTS WILL BE PERSISTENT THROUGH THE END OF THE WEEK...FORCING WIND-
DRIVEN WAVES TO 4-7 FT EACH DAY. THE SEA SPECTRUM WILL BE
COMPRISED OF A NE WIND CHOP AND AN INCREASING-PERIOD NE SWELL DUE
TO THE LONG NE FETCH.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 6:18 AM WEDNESDAY...STATIC PATTERN FOR THE EXTENDED AS HIGH
PRESSURE CONTINUES TO PUSH DOWN THE COAST...PINCHING THE PRESSURE
GRADIENT ACROSS THE WATERS AND CREATING GUSTY NE WINDS THROUGH THE
WKND...ALTHOUGH SOME RELAXING IS LIKELY LATE. WINDS FROM THE NE
WILL BE 15-20 KTS SATURDAY AND INTO SUNDAY...BEFORE SLOWLY EASING
LATE AS RIDGE BREAKS DOWN SLIGHTLY WITH A WEAKENING GRADIENT.
THESE WINDS WILL HELP DRIVE SEAS TO 4-6 FT SATURDAY WHEN AN SCA
WILL LIKELY BE NEEDED...BEFORE FALLING SLOWLY SUNDAY TO 3-5 FT.
SEA SPECTRUM WILL CONSIST OF NE WIND WAVE AND A DECAYING NE SWELL.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 6 PM EDT
THURSDAY FOR AMZ250-252-254-256.
&&
$$
NEAR TERM...REK
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...BJR
MARINE...REK/JDW
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1128 AM CDT WED MAY 1 2013
.UPDATE...
A STALLED FRONTAL BOUNDARY EXTENDS FROM ROUGHLY FROM SHEBOYGAN
THROUGH MADISON THROUGH MONROE LATE THIS MORNING...MARKED BY
SOUTHERLY WINDS ON THE SOUTH SIDE AND NORTHERLY WINDS ON THE NORTH
SIDE. HRRR IS DOING A NICE JOB HANDING THE CURRENT LOCATION OF THE
FRONT...AND SHOWS THAT FRONT LIFTING NORTHWARD A BIT THIS AFTERNOON.
TEMPERATURES ARE WARMING QUICKLY SOUTH OF THE FRONT...AND WARMING
SLOWLY NORTH OF IT. RACINE HAS ALREADY HIT 82 AND MILWAUKEE WILL HIT
LOWER 80S AS WELL. THERE IS A LOT MORE UNCERTAINTY FOR HIGH TEMPS IN
MADISON... WITH THE FRONT WAFFLING AROUND RIGHT OVER THE CITY TODAY.
THERE IS A WEAK ENOUGH PRESSURE GRADIENT OVER SOUTHEAST WISCONSIN TO
ALLOW A LAKE BREEZE TO DEVELOP. TIMING OF THIS LAKE BREEZE IS VERY
UNCERTAIN...BUT SOUTHEAST WINDS COULD DEVELOP AT MILWAUKEE AIRPORT
BY 1 PM TODAY AND MOVE INLAND TO KENOSHA BY MID AFTERNOON. SCATTERED
CUMULUS CLOUDS COULD DEVELOP ALONG THE LAKE BREEZE THIS
AFTERNOON...BUT CLEAR SKIES ARE EXPECTED ELSEWHERE.
REMOVED ANY POPS NORTHWEST OF MADISON FOR TODAY. IT APPEARS THAT ANY
LIGHT RAIN DEVELOPING WELL BEHIND THE COLD FRONT WILL REMAIN
NORTHWEST OF THE MKX FORECAST AREA DURING THE DAY. EXPECT SOME RAIN
TO SPREAD INTO NORTHWEST AREAS OVERNIGHT...AND INTO PORTIONS OF
SOUTHEAST WI THURSDAY MORNING. CUT BACK ON POPS FOR THE EVENING AND
WILL CONTINUE TO EVALUATE PRECIP CHANCES THROUGH THU.
THE 13Z HRRR AND 12Z NAM AND REGIONAL CANADIAN MODELS ARE STILL
ADVERTISING THIS COLD FRONT CHARACTERIZED BY NNE GUSTY WINDS RACING
DOWN THE LAKE...SOMETIMES CALLED A PNEUMONIA FRONT...TO OCCUR EITHER
LATE AFTERNOON OR EARLY THIS EVENING. THERE IS STILL UNCERTAINTY
ABOUT WHETHER LOW CLOUDS WILL DEVELOP WITH THE FRONT OR NOT. THERE
ARE NO SIGNS OF LOW CLOUDS AT THIS TIME.
&&
.AVIATION/18Z TAFS/...
LAKE BREEZE WILL DEVELOP EARLY THIS AFTERNOON FROM MILWAUKEE AND
SOUTH...ALTHOUGH TIMING IS VERY UNCERTAIN. VFR CUMULUS CLOUDS COULD
DEVELOP ALONG THE LAKE BREEZE. ELSEHWERE...WINDS WILL BE NORTH TO
NORTHEAST ON THE NORTH SIDE OF A STALLED FRONT. WINDS WILL BE
SOUTHWEST TO SOUTH ON THE SOUTH SIDE OF THE FRONT. THE FRONT WILL BE
WAFFLING AROUND ACROSS THE CENTRAL PORTION OF SOUTHERN
WISCONSIN...INCLUDING MADISON...WATERTOWN AND WAUKESHA.
VFR CONDITIONS FOR MOST OF THE PERIOD...HOWEVER NEED TO WATCH FOR
POTENTIAL LOW CLOUDS FORMING NEAR LAKE MICHIGAN IN MOIST ONSHORE
FLOW TONIGHT AND SPREADING WESTWARD. CLOUDS WOULD BE IFR CAT.
&&
.PREV DISCUSSION... /ISSUED 326 AM CDT WED MAY 1 2013/
TODAY AND TONIGHT...FORECAST CONFIDENCE - VERY LOW.
KMKX WSR-88D CONTINUES TO SHOW SFC COOL FRONT SLIDING SOUTHEAST
ACROSS SOUTHERN WI. SFC OBS AND RADAR FINE LINE ESTIMATE BOUNDARY
ROUGHLY FROM VCNTY OF KSBM TO KEFT AT 08Z. SFC FRONT A LITTLE
FASTER THAN DEPICTED BY SHORT TERM GUIDANCE DUE TO 3 HOUR 4-6MB
PRESSURE RISES UPSTREAM OVER CENTRAL/NORTHERN WI. LOW LEVEL
FLOW APPEARS TO BE WEAKENING BEHIND FRONT SO WOULD NOT BE SURPRISED
TO SEE FRONT STALL FOR A TIME ACROSS SOUTHEAST WI. HOWEVER HIGH
PRESSURE BUILDING INTO THE PLAINS WILL ALSO BUILD INTO NORTHERN WI.
INCREASING UPSTREAM PRESSURE SHOULD EITHER GIVE NUDGE TO SFC FRONT
TO THE SOUTH...OR ELSE WILL RESULT IN PNEUMONIA-TYPE FRONT SLIDING
SOUTH DOWN LAKE MI TODAY...EVENTUALLY MELDING WITH SFC FRONT TO THE
WEST. THESE PNEUMONIA FRONTS HAVE FOUND TO BE MOST FREQUENT IN THE
MONTH OF MAY BEFORE LAKE MI WATER TEMPS BEGIN TO MODIFY.
EITHER WAY...NOT EXPECTING QUITE AS WARM A DAY ACROSS SOUTHERN
WI...WITH THE WARMEST TEMPERATURES IN THE FAR SOUTH CENTRAL INTO
PARTS OF THE SOUTHEAST...BEFORE WINDS TURN ONSHORE LATER THIS MRNG
OR EARLY AFTERNOON. HOWEVER TIMING IS CRITICAL. FOR NOW HAVE KMKE
RISING INTO THE MIDDLE TO UPPER 70S BEFORE WINDS TURN ONSHORE...BUT
COULD EASILY CRACK THE 80 MARK AGAIN IF WINDS DELAY TURNING
SEVERAL HOURS. A LARGE RANGE OF DAYTIME HIGH TEMPS ARE
EXPECTED...VARYING FROM THE MID TO UPPER 60S IN THE NORTHWEST TO THE
LOWER 80S SOUTHEAST.
MAIN FORCING ASSOCIATED WITH SLOPING FRONTOGENETICAL FORCING REMAINS
NORTHWEST OF AREA TODAY...AND WITH RH REMAINING LIMITED IN THE LOW
TO MID LEVELS...WL GO MOSTLY DRY...WITH A SMALL CHANCE IN THE AFTN
WEST OF KMSN.
LAYER Q-VECTOR CONVERGENCE AXIS BEGINS TO SLIDE EWD ACROSS SOUTHERN
WI TONIGHT AS LOW LEVEL MOISTURE GRADUALLY INCREASES. UPPER LEVEL
TROF OVER PLAINS BEGINS TO SHARPEN AND CAUSE FLOW TO PIVOT
NORTHWEST...WHILE LOW LEVEL FLOW INFLUENCED BY INCREASING ELY FLOW.
INCREASING LOW LEVEL JET RESULTS IN WEAK WAA AND SAID Q-VECTOR
CONVERGENCE TONIGHT...SO WL SPREAD SMALL POPS ACROSS ENTIRE AREA.
ELEVATED CAPE APPROACHES 1000 J/KG SO KEPT SMALL THUNDER THREAT IN
AS WELL.
THURSDAY THROUGH SUNDAY...FORECAST CONFIDENCE...LOW TO MEDIUM
THE STORY FOR LATE THIS WEEK INTO THE WEEKEND CONTINUES TO BE THE
LARGE UPPER LOW THAT WILL MEANDER THROUGH THE REGION. AS IS OFTEN
THE CASE WITH CUTOFF LOWS...MODELS CONTINUE TO STRUGGLE WITH THE
TRACK OF THIS LOW. BY SUNDAY EVENING...THE GFS AND CANADIAN HAVE THE
LOW CENTERED OVER MISSOURI...WITH THE ECMWF PUTTING IT ALONG
THE MINNESOTA/CANADA BORDER. AS A RESULT...STILL A GOOD AMOUNT
VARIANCE AMONG MODELS IN TIMING OF PRECIP CHANCES AND TEMPS
THROUGH THE WEEKEND. GENERALLY CONTINUED THE TREND OF GOING DOWN
THE MIDDLE OF THE ROAD FOR NOW. EITHER WAY...LOOKS COOLER AND WET
THROUGH THIS PERIOD.
MONDAY AND TUESDAY...FORECAST CONFIDENCE...LOW TO MEDIUM
UPPER LOW WILL FINALLY BE OUT OF THE AREA BY MONDAY...WITH A
SHORTWAVE TO IMPACT THE STATE EITHER MONDAY NIGHT OR TUESDAY
NIGHT...DEPENDING ON THE MODEL. KEPT SOME POPS THROUGH EARLY WEEK
DUE TO THE UNCERTAINTY IN TIMING. SPLIT THE DIFFERENCE IN MODEL
TEMPS...RESULTING IN NEAR NORMAL VALUES FOR EARLY MAY.
AVIATION/12Z TAFS/...VFR CONDITIONS FOR MOST OF THE
PERIOD...HOWEVER NEED TO WATCH FOR POTENTIAL LOW CLOUDS FORMING NEAR
LAKE MICHIGAN IN MOIST ONSHORE FLOW TONIGHT AND SPREADING WESTWARD.
CLOUDS WOULD BE IFR CAT. SMALL THREAT FOR -SHRA...MAINLY TNGT.
MARINE...EXPECT BUILDING SFC PRESSURE TO THE NORTH TO EITHER
CONTINUE TO NUDGE SURFACE COOL FRONT OVER SOUTH CENTRAL WI FURTHER
SOUTHEAST...OR ELSE EXPECT PNEUMONIA-TYPE FRONT TO SLIDE SOUTH
ACROSS NEARSHORE WATERS DURING THE DAY...TURNING WINDS TO THE EAST
OR NORTHEAST. WINDS AND WAVES MAY GET CLOSE TO SMALL CRAFT ADVISORY
LEVELS LATE TODAY AND TONIGHT...BUT TOO MUCH UNCERTAINTY IN TIMING
AND STRENGTH AT THIS TIME TO ISSUE HEADLINE. NEARSHORE WATER HAS
WARMED /FOR NOW/ INTO THE LOW TO MID 50S PER SGNW3 SO THREAT FOR FOG
IN THE NEARSHORE THIS MRNG APPEARS LOW. BETTER CHANCE TOWARD
MID-LAKE WHERE LAKE WATER TEMPS REMAIN AROUND 40 PER BUOY 45007.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...MRC
TODAY/TONIGHT AND AVIATION/MARINE...MBK
THURSDAY THROUGH TUESDAY...DDV