Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 05/19/15

AREA FORECAST DISCUSSION

NWS SAN FRANCISCO BAY AREA

 236 PM PDT SUN MAY 17 2015

.SYNOPSIS...BELOW NORMAL TEMPERATURES WITH MOSTLY DRY CONDITIONS
ARE EXPECTED TO CONTINUE THROUGH FRIDAY. THERE COULD BE A FEW
SHOWERS OVER INTERIOR MOUNTAINS LATE TODAY AND AGAIN THURSDAY AS
WEAK LOW PRESSURE DISTURBANCES MOVE ONSHORE. HIGH PRESSURE AND
WARMER CONDITIONS ARE EXPECTED OVER THE MEMORIAL DAY WEEKEND.

&&

.DISCUSSION...AS OF 02:16 PM PDT SUNDAY...DESPITE MID AND HIGH
CLOUDS...MANAGING TO GET A FEW CONVECTIVE BUILDUPS OVER INTERIOR
MOUNTAINS WHERE SUNSHINE IS MORE PREVALENT. HRRR MODEL CAPTURING
THE CONVECTION OVER NORTHEAST SANTA CLARA COUNTY PRETTY WELL AND
SHOULD PERSIST FOR A FEW MORE HOURS...THEN SHIFT EAST AND DECREASE
THIS EVENING. MODEL ALSO SHOWS ACTIVITY FORMING OVER EASTERN SAN
BENITO COUNTY AND PARTS OF MONTEREY COUNTY...BUT THICKER CLOUDS HAVE
LIMITED CONVECTION. WOULD EXPECT SOME BUILDUPS AND POSSIBLY A
SHOWER IN THIS AREA AS WELL LATER THIS AFTERNOON AS SOME BREAKS IN
MID CLOUDS EXPECTED. OTHER AREA TO WATCH IS EXTREME NORTH BAY OVER
ELEVATED TERRAIN...BUT NOT EXPECTING MORE THAN A FEW CUMULUS
BUILDUPS.

WELL MIXED MARINE LAYER PERSISTS AND IS AT LEAST 3000 FEET DEEP
THIS AFTERNOON NEAR THE COAST AND BAY AREA. TEMPERATURES MOSTLY IN
THE 60S AND NOT MUCH CHANGE EXPECTED IN THE CURRENT COOL
TEMPERATURE REGIME THROUGH AT LEAST THURSDAY. MARINE LAYER SHOULD
REMAIN DEEP THROUGH THE WEEK AS WELL WITH A LINGERING TROF ALONG
THE COAST. SERIES OF SHORT WAVES WILL REINFORCE THIS TROF
THROUGHOUT THE WEEK WITH ONE WAVE MOVING ACROSS THE AREA MONDAY
AND ANOTHER ONE WEDNESDAY AND THURSDAY. STRONGEST FEATURE LOOKS TO
ARRIVE THURSDAY AND PUSHES TOWARD SOUTHERN CALIFORNIA.

MAIN IMPACT ON CENTRAL CALIFORNIA COAST WEATHER WILL BE PERSISTENT
LOW CLOUDS ESPECIALLY NEAR THE COAST...COOL TEMPERATURES...AND MOSTLY
DRY WEATHER. SHOWER THREAT SHOULD BE REDUCED MONDAY AND TUESDAY AS
DYNAMICS AND MOISTURE SHIFT FURTHER INLAND. OUTSIDE CHANCE OF A
SHOWER EACH AFTERNOON IN EXTREME NORTH BAY GIVEN INSTABILITY OVER
TERRAIN. THURSDAY BRINGS A BETTER RISK FOR SHOWERS OVER INTERIOR
AS THE STRONGEST WAVE IN THE SERIES BRINGS CYCLONIC CURVATURE AND
SOME ADDED LIFT TO THE AREA.

RIDGE BUILDS INTO COAST OVER THE WEEKEND...SO DRYING AND WARMING
TREND EXPECTED FROM FRIDAY INTO SUNDAY.

&&

.AVIATION...AS OF 10:45 AM PDT SUNDAY...UPPER LOW JUST OFFSHORE ON
SUNDAY MORNING WILL MOVE SLOWLY INLAND ACROSS THE SF BAY AREA
ON SUNDAY NIGHT AND MONDAY. PERSISTENT ONSHORE FLOW ALONG WITH
SIGNIFICANT LOW LEVEL MOISTURE WILL MAINTAIN MVFR CIGS FOR MUCH OF
THE FORECAST PERIOD. MAY SEE A FEW HOURS OF VFR CONDITIONS THIS
AFTERNOON...BUT MVFR CIGS LIKELY TO REDEVELOP BY EARLY EVENING AND
PERSIST WELL INTO MONDAY. WESTERLY WINDS 10 TO 15
KNOTS...STRONGEST DURING THE LATE AFTERNOON AND EARLY EVENING
HOURS.

VICINITY OF KSFO...MVFR CIGS WILL MOST LIKELY CONTINUE TIL
21-22Z. IFR CONDITIONS WITH MID LEVEL CLOUDS EXPECTED DURING THE
LATE AFTERNOON AND EARLY EVENING HOURS BEFORE LOW CIGS REDEVELOP
BY 03Z...WITH MVFR CONDITIONS LIKELY AGAIN BY 06Z. CONFIDENCE
MODERATE. WESTERLY WINDS 10-17 KTS...STRONGEST FROM LATE AFTERNOON
THROUGH EARLY EVENING.

KSFO BRIDGE APPROACH... SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...SOME BREAKS IN THE LOW CLOUD COVER
THROUGH MID AFTERNOON...OTHERWISE PERSISTENT MVFR CIGS EXPECTED
THROUGH THE FORECAST PERIOD. LIGHT WESTERLY WINDS.

&&

.MARINE...AS OF 8:45 AM PDT SUNDAY...RELATIVELY LIGHT
NORTHWESTERLY WINDS WILL PREVAIL OVER THE COASTAL WATERS THROUGH
MIDWEEK.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TNGT...NONE.

$$

PUBLIC FORECAST: KBB
AVIATION/MARINE: DYKEMA

VISIT US AT WEATHER.GOV/SANFRANCISCO

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AREA FORECAST DISCUSSION

NWS SAN JOAQUIN VALLEY - HANFORD CA

 213 PM PDT SUN MAY 17 2015

.SYNOPSIS...
LOW PRESSURE WILL REMAIN OVER THE REGION UNTIL MONDAY NIGHT AND
BRING A CHANCE OF SPRINKLES AND LIGHT RAIN OVER THE SAN JOAQUIN
VALLEY...AS WELL AS AFTERNOON SHOWERS AND THUNDERSTORMS OVER THE
SIERRA NEVADA AND ADJACENT FOOTHILLS. AFTERWARD...GENERALLY DRY
CONDITIONS AND NEAR AVERAGE TEMPERATURES ARE EXPECTED...EXCEPT FOR
AFTERNOON AND EVENING SHOWERS WITH ISOLATED THUNDERSTORMS OVER THE
HIGHER ELEVATIONS OF THE SIERRA NEVADA...FOR THE REST OF THIS WEEK.

&&

.DISCUSSION...AN UPPER TROUGH...CURRENTLY IMPACTING THE WEST COAST
OF CALIFORNIA...WILL CONTINUE SHIFT EAST OVER CENTRAL
CALIFORNIA...RESULTING IN BELOW NORMAL TEMPERATURES AND UNSETTLED
WEATHER. SCATTERED SHOWERS WERE OBSERVED IN THE SIERRA NEVADA
EARLY THIS AFTERNOON...WITH A FEW LOCATIONS IN TULARE COUNTY
REPORTING RAINFALL RATES AROUND 0.05" PER HOUR. THIS SHOWER
ACTIVITY OVER THE SIERRA CREST IS FORECAST TO INCREASE INTO THE
EARLY EVENING HOURS AS THE HIGH RES ARW...NMM...AND HRRR ARE ALL
IN GOOD AGREEMENT ABOUT THIS INCREASE IN ACTIVITY.
ADDITIONALLY...SCATTERED THUNDERSTORMS ARE ALSO POSSIBLE OVER THE
HIGHER ELEVATIONS AS THE NAM...GFS...AND HIGH RES MODELS SHOW
SURFACE CAPE VALUES EXCEEDING A FEW HUNDRED J/KG. THE NAM SEEMS
TO BE THE OUTLIER WITH REGARDS TO CAPE VALUES...INDICATING OVER
1000 J/KG...WITH A BULLS EYE IN FRESNO COUNTY BETWEEN 2 PM AND 5
PM THIS AFTERNOON. WE WILL CONTINUE TO MONITOR THE CHANCE FOR
THUNDERSTORMS CLOSELY AS THE AFTERNOON PROGRESSES.

LASTLY...SPINKLES WILL BE POSSIBLE IN THE SAN JOAQUIN VALLEY AS
LIGHT RAIN SHOWERS MOVE NORTHEAST INTO THE AREA FROM SOUTHERN
CALIFORNIA.

BY MONDAY AFTERNOON THE UPPER TROUGH WILL SHIFT EAST INTO
NEVADA...HOWEVER SCATTERED SHOWERS WILL REMAIN IN THE AREA. THE
OPERATIONAL HIGH RES MODELS INDICATE SHOWERS OVER THE SIERRA CREST
AGAIN MONDAY AFTERNOON INTO THE EVENING HOURS AND ALSO THE
POSSIBILITY OF ANOTHER DAY OF SPRINKLES IN THE VALLEY. LASTLY...FEW
SHOWERS WILL ALSO BE POSSIBLE NEAR THE GRAPEVINE.

LITTLE CHANGE IN THE UPPER PATTERN THROUGH AT LEAST THE MIDDLE OF
NEXT WEEK AS A SERIES OF UPPER TROUGHS MOVES SOUTHEAST TOWARD THE
CENTRAL CALIFORNIA COAST. THIS PATTERN WILL RESULT IN DAYTIME HIGH
TEMPERATURES REMAINING BELOW NORMAL THROUGH CENTRAL CALIFORNIA AS
WELL AS AFTERNOON AND EVENING SIERRA NEVADA SHOWERS AND
THUNDERSTORMS.

BY THE WEEKEND...UPPER LEVEL HIGH PRESSURE WILL BEGIN TO BUILD
OVER THE REGION RESULTING IN A WARMING TREND ACROSS THE AREA.

&&

.AVIATION...
A FEW SHOWERS OR THUNDERSTORMS POSSIBLE OVER THE SIERRA NEVADA THIS
EVENING...OTHERWISE MAINLY VFR CONDITIONS WILL PREVAIL ACROSS THE
CENTRAL CA INTERIOR THROUGH THE NEXT 24 HOURS.

&&

.AIR QUALITY ISSUES...
NONE.

&&

.CERTAINTY...

THE LEVEL OF CERTAINTY FOR DAYS 1 AND 2 IS MEDIUM.
THE LEVEL OF CERTAINTY FOR DAYS 3 THROUGH 7 IS MEDIUM.

THIS INFORMATION IS PROVIDED AS PART OF A TRIAL PROJECT CONDUCTED
BY THE NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD.
CERTAINTY LEVELS INCLUDE LOW...MEDIUM...AND HIGH. PLEASE VISIT
WWW.WEATHER.GOV/HNX/CERTAINTY.PHP /ALL LOWER CASE/ FOR ADDITIONAL
INFORMATION AND/OR TO PROVIDE FEEDBACK.

&&

.CLIMATE...
             RECORDS
SITE DATE    HI_MAX:YEAR LO_MAX:YEAR HI_MIN:YEAR LO_MIN:YEAR

KFAT 05-17      106:2009     64:2011     73:2008     44:1974
KFAT 05-18      103:2008     63:1994     73:2008     42:1893
KFAT 05-19      103:2008     63:1972     70:2009     42:1896

KBFL 05-17      105:2009     68:1998     73:2009     41:1906
KBFL 05-18      102:2009     68:2011     76:1973     41:1893
KBFL 05-19      101:1954     65:1916     73:1979     38:1893
&&

.HNX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

PUBLIC...RILEY
AVN/FW...ANDERSEN
SYNOPSIS...BSO

WEATHER.GOV/HANFORD



AREA FORECAST DISCUSSION

NWS GRAND JUNCTION CO

 944 PM MDT MON MAY 18 2015

.UPDATE...
ISSUED AT 933 PM MDT MON MAY 18 2015

CURRENT FORECAST REMAINS ON TRACK AS SHOWERS AND THUNDERSTORMS
CONTINUE TO LIFT NORTH ACROSS THE FORECAST AREA AHEAD OF THE MAIN
UPPER LEVEL LOW WHICH CLOSES OFF OVER WESTERN UTAH LATER TONIGHT.
FEW STRONGER CELLS EARLIER THIS EVENING DROPPED AN ESTIMATED HALF
INCH OF RAIN JUST EAST OF VERNAL UTAH AND NEAR ARCHES NATIONAL
PARK. OTHERWISE...WIDESPREAD COVERAGE OF PRECIPITATION GENERALLY
UNDER A QUARTER INCH THUS FAR. HRRR REMAINS ACTIVE OVERNIGHT WITH
HEAVIER SHOWERS LIFTING NORTH INTO THE SOUTHERN VALLEYS AFTER
MIDNIGHT AND INTO THE CENTRAL ZONES AFTER 3 AM. HIGH SURFACE
MOISTURE AND MILD H7 TEMPS WILL KEEP THE SNOW LEVELS HIGH THROUGH
LATE TONIGHT...BEFORE THE LOW MOVES CLOSER AND ALLOWS TEMPS TO
DROP A BIT TO DRIVE LEVELS DOWN TO AROUND 9K BY EARLY TUESDAY
MORNING. BULK OF THE ACCUMULATIONS SNOWFALL WILL BE RIGHT AT THE
HIGHER PASSES AND ABOVE. CURRENT HIGHLIGHTS LOOK GOOD AND NO
ADJUSTMENTS WILL BE MADE AT THIS TIME.

&&

.SHORT TERM...(TONIGHT THROUGH TUESDAY NIGHT)
ISSUED AT 323 PM MDT MON MAY 18 2015

SHOWERS WERE INCREASING OVER THE AREA EARLY THIS AFTERNOON AHEAD
OF THE LATEST IN A SERIES OF PACIFIC STORMS WHICH WAS CENTERED
OVER CENTRAL CALIFORNIA. EXPECT THIS TREND TO CONTINUE DURING THE
AFTERNOON AS TEMPERATURES PEAK AND THE CENTER OF THE PACIFIC STORM
MOVES TOWARD SOUTHERN NEVADA.

A VORT LOBE ROTATING THROUGH THE BASE OF THE PACIFIC LOW/S CENTER
WILL ENHANCE LIFT OVER THE REGION TONIGHT. ADDITIONAL LIFT WILL BE
SUPPLIED BY THE A 110 KT JET ROTATING THROUGH THE BASE OF THE
TROUGH WHICH WILL GENERATE CONSIDERABLE DIVERGENCE ALOFT. SINCE
THE MOISTURE FEED IS ALREADY IN PLACE...EXPECT PRECIPITATION WILL
BECOME WIDESPREAD OVER THE MOUNTAINS WITH ACTIVITY MORE SCATTERED
OVER THE VALLEYS. MODEL QPF VALUES ARE PRETTY IMPRESSIVE WITH A
SIGNIFICANT SWATH OF AREAS IN EXCESS OF 0.50 OF AN INCH BY
12Z/TUE.

CAA COMBINED WITH DIURNAL COOLING WILL CAUSE 7H TEMPS TO COOL TO
BETWEEN 1 AND 2 DEG C WHICH TRANSLATES TO SNOW LEVELS OF AROUND
9000 TO 9500 FEET TONIGHT. THIS WILL RESULT IN SOME IMPACTS TO
TRAVEL OVER THE HIGHER PASSES WITH ROADS LIKELY BECOMING ICY AND
SNOWPACKED. MODELS HIT SNOW ACCUMULATIONS PRETTY HARD...BUT EXPECT
SIGNIFICANT SNOWFALL WILL BE LIMITED TO AREAS ABOVE THE
TIMBERLINE. THEREFORE...OPTED TO HOIST A WINTER WEATHER ADVISORY
ABOVE 9500 FEET FOR MOST MOUNTAINS ALONG THE CONTINENTAL DIVIDE IN
LIEU OF WINTER STORM WARNINGS.

TUESDAY...MOISTURE GETS WRAPPED UP AROUND THE UPPER LOW (IN
ALIGNMENT WITH QG ASCENT) THAT IS PROGGED TO BE OVER SALT LAKE
CITY. THE DEEPER MOISTURE WILL BE LIFTING NORTHWARD WITH
WIDESPREAD RAINFALL EXPECTED TO SHIFT TO THE NORTH. ISENTROPIC
FIELDS SHOW COLD ADVECTION FOLLOWING THE CLOUD MASS/RAIN SHIELD.
CONVECTIVE POTENTIAL IS NOT VERY HIGH WITH CAPE VALUES BELOW 500
J/KG...BUT MID LEVEL COLD ADVECTION COMBINED WITH POTENTIAL
VORTICITY ALOFT WILL ENHANCE DESTABILIZATION IN SPITE OF A RAIN
COOLED AIR MASS. TOTAL RAIN AMOUNTS WILL BE SUBSTANTIAL BUT
VARIABLE...RANGING FROM AROUND ONE HALF INCH /0.50/ IN MANY
VALLEYS AND UPWARD TO 2 INCHES IN THE HIGH COUNTRY. AS THE UPPER
LOW CONTINUES TO SHIFT NORTHWARD (AND SPLITS APART)...SHOWERS WILL
BE DIMINISHING FROM SOUTH TO NORTH ON TUESDAY NIGHT.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 323 PM MDT MON MAY 18 2015

NEARLY DEJA VU IN THE LONG TERM PERIOD AS THE "RINSE/REPEAT" CYCLE
GETS PLAYED OUT ONCE AGAIN. THE NEXT UPSTREAM WAVE CARVES OUT A
DEEP TROUGH ALONG THE CALIFORNIA/BAJA COAST. AS THIS EVOLVES...A
RIDGE AXIS ALIGNS ITSELF WITH THE CENTRAL ROCKIES SPINE AND DRIER
SOUTHWEST FLOW DEVELOP. IN THIS CASE...DRIER DOES NOT MEAN NO RAIN
AS DIURNAL DRIVEN SHOWERS/THUNDER FORM OVER THE HIGHER TERRAIN ON
WEDNESDAY.

THURSDAY AFTERNOON/NIGHT...THE SRN CALIFORNIA UPPER LOW EJECTS A
SHORT WAVE THAT REACHES THE FOUR CORNERS AREA THURSDAY AFTERNOON
AND CONVECTIVE SHOWERS/THUNDER WILL BE ON THE INCREASE.

FRIDAY AND SATURDAY...THE MAIN UPPER LOW MOVES TOWARD WRN COLORADO
WITH GOOD AGREEMENT BETWEEN THE GFS/ECMWF MODELS THAT THE CORE
WILL BE OVERHEAD ON SATURDAY AFTERNOON. ANOTHER OPPORTUNITY FOR
WIDESPREAD CONVECTIVE SHOWERS/THUNDER. AHEAD OF THIS FEATURE IS QG
FORCING THAT BOOSTS THE THREAT OF ROBUST SHOWERS (ISOLATED STRONG
STORMS). SATURDAY WILL BE THE COOLEST DAY OF THE HOLIDAY WEEKEND
WITH 40S IN THE MOUNTAINS AND 60S IN THE VALLEYS.

THE REMAINDER OF THE MEMORIAL DAY WEEKEND CONTINUES TO BE
UNSETTLED...IN SPITE OF THE UPPER LOW MOVING DOWNSTREAM.
CONDITIONAL INSTABILITY WILL EXIST SUNDAY AND MONDAY AFTERNOON AND
LEADS TO MOUNTAIN CONVECTION...WITH SUFFICIENT SHEAR ALLOWING FOR
SHOWERS/STORMS TO ROLL OFF THE HIGHER TERRAIN AND GET VALLEY
LOCATIONS. AFTERNOON TEMPS WILL BE WARMER ON SUNDAY AND MEMORIAL
DAY...BUT STAY BELOW NORMAL. POSSIBLY NO 80 DEGREE WEATHER
ANYWHERE FOR THE WEEKEND...HOW OFTEN DOES THAT HAPPEN FOR MEMORIAL
DAY WEEKEND?

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 933 PM MDT MON MAY 18 2015

WIDESPREAD RAIN AND HIGH MOUNTAIN SNOW WILL CONTINUE ACROSS THE
REGION THROUGH TONIGHT...WITH SHOWERS BECOMING MORE SCATTERED IN
NATURE BY TUESDAY AFTERNOON. ISOLATED THUNDERSTORMS WILL ALSO
CONTINUE. EXPECT OCCASIONAL MVFR TO IFR CIGS AND VSBYS NEAR THE
STRONGER SHOWERS...WITH MOUNTAIN TOPS FQTLY OBSCURED THROUGH
TUESDAY AFTERNOON. SHOWERS END TUESDAY EVENING WITH VFR WEATHER
RETURNING TO MUCH OF THE FORECAST AREA.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER WEATHER ADVISORY UNTIL NOON MDT TUESDAY FOR COZ010-012-
     013-018-019.

UT...NONE.
&&

$$

UPDATE...JDC
SHORT TERM...NL/PF
LONG TERM...PF
AVIATION...JDC



AREA FORECAST DISCUSSION

NWS GRAND JUNCTION CO

 331 PM MDT SUN MAY 17 2015

.SHORT TERM...(TONIGHT THROUGH MONDAY NIGHT)
ISSUED AT 331 PM MDT SUN MAY 17 2015

IN SPITE OF BUILDING HIGH PRESSURE OVER UTAH AND WARMING TEMPS
ALOFT...AFTERNOON CAPE VALUES OF 250-500 J/KG SUGGEST CONVECTIVE
SHOWERS WITH SOME THUNDERSTORMS. MOISTURE TRANSPORT DOES EXIST
FROM THE UINTA MOUNTAINS TOWARD VAIL AND INDEPENDENCE PASS
REGION...AND SHOWERS/STORMS WILL BE CONCENTRATED ACROSS THIS AREA.
CONVECTIVE POTENTIAL EXIST ELSEWHERE BUT NOT AS NUMEROUS OVER SW
COLORADO...AND MOSTLY DRY OVER SE UTAH.

CONVECTIVE POTENTIAL MOSTLY DIMINISHES WITH SUNSET. NOT SO SURE
THIS WILL BE THE CASE ACROSS PARTS OF ERN UTAH AS MOISTURE
TRANSPORT INCREASES OVERNIGHT...THE HRRR SHOW CONVECTIVE SHOWERS
PERSISTING PAST MIDNIGHT AND TRACKING OVER THE UINTA
BASIN/MOUNTAINS. BY DAYBREAK...HIGH CLOUDS WILL BE SPREADING FROM
THE SOUTH AS THE NEXT CALIFORNIA UPPER LOW ADVECTS MOISTURE
TOWARDS THE FOUR CORNERS REGION.

THE PACIFIC WAVE TRAIN CONTINUES MONDAY AS THE NEXT STORM SYSTEM
MOVES SLOWLY ONSHORE...ITS CENTER SETTLING OVER CALIFORNIA/S SAN
JOAQUIN VALLEY LATE IN THE AFTERNOON. SOUTHERLY FLOW AHEAD OF THE
TROUGH WILL CAUSE MOISTURE LEVELS TO RISE ONCE AGAIN AS GULF
MOISTURE IS TAPPED. GFS AND NAM BOTH INDICATED PRECIPITABLE WATER
VALUES RISING TO NEAR 0.6 OF AN INCH. MEANWHILE...AN 110 KT JET
ROTATES THROUGH THE BASE OF THE TROUGH GIVING IT A SLIGHTLY
NEGATIVE TILT. THE NOSE OF THE JET PUSHES TOWARD THE FOUR CORNERS
WHICH WILL PROVIDE CONSIDERABLE DIVERGENCE TO ADD TO THE DIFFLUENT
FLOW ALOFT. THE DYNAMIC LIFT JUST DESCRIBED COMBINED WITH DAYTIME
HEATING WILL GENERATE SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS FAVORING THE MOUNTAINS. AS MENTIONED IN THE PREVIOUS
DISCUSSION...ARRIVING MOISTURE WILL BE HIGH BASED ACCORDING TO
AREA TIME SECTIONS SO EXPECT MAIN STORM THREAT...ASIDE FROM
LIGHTNING...WILL BE STRONG AND GUSTY OUTFLOW WINDS. WAA ADVECTION
WILL CAUSE TEMPERATURES TO CLIMB CLOSER TO SEASONAL NORMS...
THOUGH EXPECT CLOUDS AND SHOWERS WILL LIMIT HIGHS. THEREFORE...
NUDGED MONDAY/S HIGHS TOWARD COOLER MAV GUIDANCE.

MONDAY NIGHT WILL REMAIN ACTIVE AS THE PACIFIC SYSTEM MOVES OVER
SOUTHERN NEVADA DURING THE NIGHT. DIFFLUENT/DIVERGENT FORCING
REMAINS IN PLACE WHILE MOISTURE CONTINUES TO STREAM INTO THE AREA
FROM THE SOUTH. AS A RESULT...WILL CONTINUE WITH LIKELY POPS IN
THE MOUNTAINS WITH CHANCE POPS ACROSS THE VALLEYS. COLDER AIR
BEGINS TO ADVECT OVER THE REGION DURING THE NIGHT CAUSING SNOW
LEVELS TO LOWER TO AROUND 9000 TO 9500 FEET. EXPECT ACCUMULATING
SNOW FOR AREAS ABOVE 10000 FEET WITH AMOUNTS OF UP TO 8 INCHES
POSSIBLE ABOVE THE TIMBERLINE. MODELS SUGGEST AMOUNTS OF 12 INCHES
OR MORE BUT APPEARS CONVECTIVE PARAMETERIZATION MAY BE A BIT
OVERDONE AS LAPSE RATES ONLY MODERATELY UNSTABLE. IMPACTS TO
ROADWAYS OVER THE HIGH PASSES PROBABLY NEGLIGIBLE WITH MOST SNOW
MELTING ON CONTACT SO WILL HOLD OFF ISSUING HILITES. CLOUDS...
SHOWERS AND WAA WILL YIELD MILDER OVERNIGHT LOWS AS PREVIOUSLY
FORECAST.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 331 PM MDT SUN MAY 17 2015

COOL AND UNSETTLED CONDITIONS WILL CONTINUE TUESDAY AS THE
PACIFIC STORM MOVES OVER THE REGION. SNOW LEVELS WILL RISE WITH
DAYTIME WARMING...ESPECIALLY SOUTH...WHICH WILL INHIBIT ANY
ADDITIONAL ACCUMULATIONS BELOW 10000 FEET. CONDITIONS IMPROVE
TUESDAY NIGHT AS A TRANSIENT SHORTWAVE RIDGE BUILDS OVER THE AREA.

ANOTHER LOW DEVELOPS OVER THE EASTERN PACIFIC AT MIDWEEK BUT STAYS
QUASI-STATIONARY UNTIL THURSDAY NIGHT. A DRIER SOUTHWEST FLOW
WILL MOVE OVER THE FORECAST AREA AHEAD OF THIS SYSTEM LIMITING
MOIST CONVECTION TO THE MOUNTAIN AREAS DURING THE AFTERNOON AND
EVENING WEDNESDAY AND THURSDAY. TEMPERATURES WILL RECOVER DURING
THIS PERIOD REACHING NEAR NORMAL LEVELS THURSDAY AFTERNOON.

THE PACIFIC SYSTEM THEN FOLLOWS THE WELL BEATEN PATH PREVIOUS
STORMS HAVE TAKEN OVER THE PAST COUPLE OF WEEKS...TRACKING OVER
EASTERN UTAH AND WESTERN COLORADO FRIDAY AND SATURDAY.
CONSEQUENTLY...LOOK FOR AN UPTICK IN SHOWER AND THUNDERSTORM
ACTIVITY ONCE AGAIN ALONG WITH COOLER THAN NORMAL TEMPERATURES.
CONDITIONS ON SUNDAY LESS CERTAIN AS LATEST ECMWF DRIVES A
SHORTWAVE TROUGH ACROSS THE REGION FROM THE NORTHWEST WHILE GFS
FAVORS A TRANSITORY RIDGE. BOTH SOLUTIONS POINT TO A CONTINUATION
OF UNSETTLED CONDITIONS AS MOISTURE WILL LINGER IN EITHER CASE.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1135 AM MDT SUN MAY 17 2015

CONVECTIVE SHOWERS WILL INCREASE AFTER 18Z...ESPECIALLY OVER NW
COLORADO WHERE NUMEROUS SHOWERS ARE EXPECTED OVER THE CENTRAL
MOUNTAINS. SKI COUNTRY TAF SITES (KASE...KEGE...KRIL) MOST LIKELY
WILL HAVE SHOWERS MOVE ACROSS THESE SITES WITH CIGS BELOW ILS
BREAKPOINTS. IN BETWEEN PASSING SHOWERS...VFR CONDITIONS MAY
OCCUR.

SHOWERS WILL BE DIMINISHING BETWEEN AFTER 01Z AND ENDING BY 06Z.
VFR PREVAILS OVERNIGHT AND MONDAY MORNING WITH NO AVIATION HAZARDS
EXPECTED.


&&

.GJT WATCHES/WARNINGS/ADVISORIES...

CO...NONE.
UT...NONE.

&&

$$

SHORT TERM...PF/NL
LONG TERM...NL
AVIATION...PF



AREA FORECAST DISCUSSION

NWS NEW YORK NY

 140 PM EDT SUN MAY 17 2015

.SYNOPSIS...
A BACKDOOR COLD FRONT APPROACHES FROM THE NORTH THIS
AFTERNOON...THEN DROPS SOUTHWEST ACROSS THE AREA TONIGHT. THE
FRONT STALLS JUST SOUTHWEST OF THE REGION ON MONDAY WITH HIGH
PRESSURE BUILDING IN FROM THE NORTHEAST. THIS FRONT WILL LIFT
THROUGH AS A WARM FRONT TUESDAY MORNING...FOLLOWED BY A COLD
FRONTAL PASSAGE TUESDAY EVENING. HIGH PRESSURE IS THEN IN CONTROL
INTO NEXT WEEKEND...WITH THE EXCEPTION OF A WEAK COLD FRONTAL
PASSAGE ON FRIDAY

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LOOKING AT DEVELOPING CUMULUS FIELD ON SATELLITE OVER THE LOWER
HUDSON VALLEY/NE NJ...SO AT THIS POINT HAVE NO REASON TO NOT
BELIEVE HRRR IDEA OF ISOLATED SHOWERS DEVELOPING THERE THIS
AFTERNOON.

WHILE ANY SHRA...WITH VERY LOW CHANCE OF A TSTM...WILL BE OF THE
HIT AND MISS VARIETY...GIVEN LIGHT WINDS ALOFT WILL BE SLOW TO
MOVE...SO COULD PRODUCE LOCALLY HEAVY RAINFALL. ONCE AGAIN...FAR
MORE LIKELY FOR A MISS THAN A HIT ON A SHRA AT ANY GIVEN LOCATION
OVER THE LOWER HUDSON VALLEY/NE NJ/NYC THIS AFTERNOON.

MADE MINOR CHANGES TO TEMPERATURES THIS UPDATE WITH VALUES
EXPECTED TO BE AROUND 10-15 DEGREES ABOVE NORMAL AS A RESULT.

SEABREEZES HAVE DEVELOPED A TAD AHEAD OF SCHEDULE...BUT BASED ON
LATEST TRENDS SHOULD BE SLOW TO MOVE INLAND...ESPECIALLY ACROSS
LONG ISLAND/NYC.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
UPPER LEVEL RIDGE AXIS BUILDS EAST ACROSS NEW ENGLAND
TONIGHT...WHICH IN TURN STRENGTHENS HIGH PRESSURE OVER THE
CANADIAN MARITIMES AND SENDS A BACKDOOR COLD ACROSS THE AREA BY
DAYBREAK. THE FRONT WILL STALL JUST SOUTHWEST OF THE FORECAST
AREA ON MON. HOWEVER..DUE TO THE CLOSE PROXIMITY OF THE BOUNDARY
CAN NOT RULE OUT SHOWERS...PRIMARILY FROM NYC AND POINTS WEST.
CLOUDS MOVE IN BEHIND THE COLD FRONT LATE TONIGHT AS A MOIST E
FLOW DEVELOPS ACROSS THE REGION. SOME CLEARING IS POSSIBLE MON
AFTERNOON ACROSS EASTERN LONG ISLAND/SE CT...WITH A MOSTLY CLOUDY
SKY FURTHER WEST.

LOWS TONIGHT WILL REMAIN MILD WITH THE CLOUD COVER AND DEVELOPING
EAST FLOW...HOWEVER...FOR THOSE SAME REASONS WILL BE ABOUT 5
DEGREES BELOW NORMAL ON MON.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
MODELS ARE IN GOOD AGREEMENT WITH THE H5 PATTERN THROUGH THE MIDDLE
OF NEXT WEEK. A VORTEX DEVELOPS OVER SE CANADA AT THE END OF THE
WEEK WITH ZONAL FLOW BECOMING SW ALOFT AS A PIECE OF ENERGY MOVING
AROUND THE BASE RESULTS IN AMPLIFICATION.

WARM FRONT LIFTS THROUGH TUE MORNING FOLLOWED BY A COLD FRONT IN
THE EVE WITH A BETTER CHANCE FOR WIDESPREAD SHOWERS/TSTMS. HIGH
PRESSURE THEN BUILDS IN FROM THE W AND REMAINS IN CONTROL THROUGH
THE END OF THE WEEK...WITH THE EXCEPTION OF MAYBE A SHOWER
ASSOCIATED WITH A WEAK COLD FRONT DROPPING THROUGH THE AREA ON FRI
AFTERNOON/EVE.

TEMPERATURES WILL GENERALLY BE ABOVE NORMAL LEVELS THROUGH THE
PERIOD.

&&

.AVIATION /17Z SUNDAY THROUGH THURSDAY/...
A COLD FRONT APPROACHES FROM THE NORTH TODAY WITH VFR CONDITIONS
THROUGH THIS EVENING. THE FRONT MOVES THROUGH THE TERMINALS LATE
TONIGHT INTO MONDAY MORNING.

WITH LIGHT FLOW OVER THE AREA...WINDS HAVE BEEN VARIABLE.
SOUTHERLY SEA BREEZES WILL CONTINUE MOVING THROUGH MOST TERMINALS.
OTHERWISE...WINDS SHOULD AVERAGE OUT OF THE SOUTHWEST WHERE SEA
BREEZES DO NOT MOVE THROUGH. SPEEDS WILL BE 5 TO 10 KT...HIGHEST
NEAR THE COAST.

AN ISOLATED SHOWER IS POSSIBLE THIS AFTERNOON AT KEWR/KTEB.

WINDS DIMINISH TO 5 KT OR LESS AFTER 02-03Z TIME FRAME. BEHIND
THE FRONT...WINDS WILL BE OUT OF THE NE-ENE 5 TO 10 KT MONDAY
MORNING.

STRATUS/FOG DEVELOPS AROUND 09Z WITH IFR CONDS AND A LOW CHANCE
OF LIFR IN VISIBILITIES. SLIGHT IMPROVEMENT TO MVFR EXPECTED
AROUND 15Z...BUT IFR CONDS COULD LAST LONGER THAN CURRENTLY
FORECAST.

.OUTLOOK FOR 18Z MONDAY THROUGH FRIDAY...
.MONDAY AFTERNOON-MONDAY EVENING...MVFR CIGS LIKELY IN STRATUS.
.LATE MONDAY NIGHT-TUESDAY EVENING...MVFR OR LOWER POSSIBLE IN
FOG/STRATUS AND/OR SHRA/TSTM.
.TUESDAY NIGHT-THURSDAY...VFR. NW WINDS G20+KT POSSIBLE ON
WEDNESDAY.

&&

.MARINE...
MADE MINOR CHANGES THIS UPDATE TO REFLECT THE LATEST TRENDS IN
OBSERVATIONS AND GUIDANCE. THE FORECAST APPEARS ON TRACK.

A BACKDOOR COLD FRONT APPROACHES THE WATERS FROM THE NORTH THIS
AFTERNOON AND PASSES TO SOUTH OF THE WATERS BY EARLY MONDAY
MORNING. THE PRESSURE GRADIENT GRADUALLY TIGHTENS AS HIGH PRES
BUILDS ALONG THE NEW ENGLAND COAST AND A COLD FRONT APPROACHES
FROM THE WEST. THAT FRONT MOVES ACROSS THE WATERS LATE
TUESDAY...AND THEN HIGH PRES RETURNS FOR THE MIDDLE OF THE WEEK.

SUB-SMALL CRAFT ADVISORY CONDITIONS ON TAP THROUGH MONDAY...AND
THEN SCA CONDITIONS EXPECTED ON WEDNESDAY BEHIND THE DEPARTING
COLD FRONT.

&&

.HYDROLOGY...
GENERALLY LIGHT RAINFALL AMOUNTS ARE POSSIBLE IN ANY SHOWERS THE
NEXT COUPLE OF DAYS...MAINLY WEST OF NYC.

HOWEVER...ANY SHOWERS WHICH DO FORM THIS AFTERNOON WILL BE VERY
SLOW TO MOVE. IF ANY STRONGER CONVECTION WERE TO FORM OVER A
LOCATION...THERE WOULD BE THE POTENTIAL FOR THE PONDING OF WATER
ON ROADWAYS AND POSSIBLY MINOR POOR DRAINAGE FLOODING DEPENDING ON
THE EXACT DURATION AND STRENGTH OF ANY GIVEN SHOWER WHICH MIGHT
FORM.

AROUND 1/4 OF AN INCH OF RAINFALL IS POSSIBLE WITH THE FRONTAL
SYSTEM ON TUE.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...MALOIT/DW
NEAR TERM...MALOIT/DW
SHORT TERM...DW
LONG TERM...24/DW
AVIATION...DS
MARINE...MALOIT/MPS
HYDROLOGY...MALOIT/DW



AREA FORECAST DISCUSSION

NWS ALBANY NY

 109 PM EDT SUN MAY 17 2015

.SYNOPSIS...
A COLD FRONT WILL DRIFT SOUTH OF THE REGION TODAY...AS
HIGH PRESSURE WILL BUILD IN FROM SOUTHEASTERN CANADA. THE FRONTAL
BOUNDARY WILL BE STATIONARY SOUTH OF EAST CENTRAL NEW YORK TONIGHT
INTO MONDAY BEFORE A LOW PRESSURE SYSTEM AND COLD FRONT APPROACHES
FROM THE GREAT LAKES REGION AND THE MIDWEST WITH INCREASING CHANCES
OF SHOWERS AND THUNDERSTORMS LATE MONDAY INTO TUESDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1230 PM EDT...MESOSCALE ANALYSIS REVEALS THE COLD FRONT HAS
STALLED ALONG OUR SOUTHERN PERIPHERY OF OUR CWFA. LAPS/SPC
ANALYSIS WINDOWS SUGGEST SBCAPES HAVE RISEN TO NEAR 1K J/KG.
HOWEVER...THE 12Z SOUNDINGS FROM KALB-KOKX...SHOW THE INVERSION
LAYER WAS BELOW -20C SO THE POTENTIAL FOR THUNDER LOOKS RATHER
LOW. HOWEVER...DPROG/DT OF THE HRRR REFLECTIVITY FORECASTS HAVE
SHOWN AN INCREASE OF ISOLATED SHOWERS SO WITH THIS UPDATE WE WILL
PLACE A SLIGHT CHANCE POPS FOR ULSTER/DUTCHESS/LITCHFIELD COUNTIES
WITH MAINLY THE SOUTHERN PORTIONS OF THESE COUNTIES. THE H2O VAPOR
LOOP DOES SHOW HINTS OF A WEAK SHORT WAVE OVER WESTERN NY WITH
RAP13/HRRR FORECASTS MOVING THIS FEATURE ACROSS THE SOUTHERN
PORTIONS OF THE REGION TO FURTHER SUPPORT THE SLIGHT CHANCE
UPGRADE FOR SHOWERS. OTHERWISE...A DELIGHTFUL END TO THE WEEKEND
WITH TEMPERATURES CLIMBING INTO THE LOWER HALF OF THE 80S WITH 70S
ACROSS THE HIGHER TERRAIN.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
TONIGHT...THE SFC CYCLONE DRIFTS N/NE OF UPSTATE NY OVER NRN
MAINE AND THE CANADIAN MARITIMES. THE MID-LEVEL RIDGE AXIS SETS UP
OVER ERN NY AND WRN NEW ENGLAND. A CLEAR/MOSTLY CLEAR AND COOL
NIGHT IS EXPECTED WITH SOME RADIATIONAL COOLING EXPECTED EARLY
ON. SOME STRATUS MAY START TO MOVE IN SOUTH OF MASS PIKE AND OVER
THE MID HUDSON VALLEY BTWN 09Z-12Z MONDAY MORNING. LOWS WILL
GENERALLY BE IN THE MID TO U50S FROM THE CAPITAL REGION...MOHAWK
VALLEY...AND BERKSHIRES SOUTH...AND M40S TO L50S TO THE NORTH.

MONDAY...A BACKDOOR COLD FRONT DRIFTS WESTWARD ACROSS THE
REGION...AND STALLS OVER CNTRL NY WITH THE SFC HIGH BUILDING IN
FROM THE GULF OF MAINE AND NEW BRUNSWICK. LOW PRESSURE UPSTREAM
OVER THE UPPER MIDWEST/WRN GREAT LAKES REGION WILL EDGE CLOSER
ASSOCIATED WITH A POSITIVELY TILTED UPPER TROUGH. A FEW ISOLATED
SHOWERS WILL BE POSSIBLE OVER WRN NEW ENGLAND AND THE HIGHER
TERRAIN OF EASTERN NY WITH THE BACKDOOR FRONT. IT WILL BE CLOUDY
AND COOLER THAN SUNDAY. A MID-LEVEL SHORT-WAVE IN THE SW
FLOW...AND THE BACKDOOR FRONT WILL TRY TO MOVE BACK EASTWARD AS A
WARM FRONT DURING THE MID TO LATE AFTERNOON TO INCREASE THE THREAT
OF SHOWERS AND PERHAPS SOME ISOLATED THUNDERSTORMS WEST OF THE
HUDSON VALLEY. HIGHS WILL ONLY BE IN THE MID 60S TO NEAR 70F OVER
WRN NEW ENGLAND. EXPECT U60S TO M70S OVER ERN NY.

MONDAY NIGHT...THE WARM FRONT OR PREFRONTAL THERMAL TROUGH TO THE
SYSTEM WILL SLOWLY MOVE ACROSS THE REGION. MOISTURE POOLS AHEAD OF
THE TROUGH WITH SFC DEWPTS RISING INTO THE 50S. THE LATEST
SHOWALTER VALUES LOWER TO 0 TO -1C WITH SOME MUCAPE. THE
INCREASING MOISTURE CONVERGENCE WITH RISING PWAT VALUE A FEW
STANDARD DEVIATIONS ABOVE NORMAL SHOULD ALLOW FOR A BAND OR BANDS
OF SHOWERS WITH EMBEDDED THUNDERSTORMS. INITIALLY THESE SHOWERS
AND STORMS WILL BE NORTH AND WEST OF THE CAPITAL DISTRICT PRIOR TO
06Z/TUE...AND THEN FROM THE CAPITAL DISTRICT SOUTH AND EAST BTWN
06Z- 12Z. POPS WERE KEPT IN THE LIKELY RANGE...EXCEPT HIGH CHC
FOR THE MID HUDSON VALLEY...SRN BERKS...AND NW CT. LOWS WILL BE OF
THE WET BULB VARIETY WITH M50S TO AROUND 60F.

TUESDAY...A HUMID AIR MASS WILL BE OVER THE REGION WITH LIMITED
INSOLATION DUE TO THE CLOUD COVER EARLY. IF THE CLOUDS
THIN...THEN MODEST AMOUNTS OF SFC BASED INSTABILITY IN THE
500-1000 J/KG RANGE MAY MATERIALIZE BASED ON THE GFS. LIFTED
INDICES IN THE -3C TO -5C RANGE WITH STRENGTHENING 0-6 KM BULK
SHEAR TO 30 TO 40 KTS BY 18Z/TUE...AND 40-50 KTS BY 00Z/WED. THE
MID LEVEL LAPSE RATES LOOK WEAK UNTIL THE NIGHT TIME PERIOD. SOME
DEEP ORGANIZED CONVECTION IS POSSIBLE...BUT WHETHER IT IS STRONG
TO SEVERE IS STILL A BIT UNCLEAR DUE TO POTENTIAL CLOUD
COVER...AND HOW MUCH INSTABILITY IS AVAILABLE. THE LATEST SPC DAY
3 CAME OUT WITH A MARGINAL THREAT FOR MOST OF THE REGION. THAT
SEEMS REASONABLE WITH THE APPROACHING FRONT AND PERHAPS AN
ISOLATED THREAT FOR A FEW SEVERE IF ANY ORGANIZED LINE GETS GOING.
PWATS WILL STILL BE IN THE INCH TO INCH A THIRD RANGE...AND SOME
LOCALLY HEAVY RAINFALL WILL BE POSSIBLE. HIGHS WILL BE IN THE
70-75F RANGE IN THE VALLEY AREAS...AND M60S TO NEAR 70F OVER THE
MTNS.

TUESDAY NIGHT...THE SFC COLD FRONT MOVES THROUGH...AND THE UPPER
LEVEL TROUGH AXIS WILL BE FOLLOWING IT. THE BEST CHC OF SHOWERS
WILL BE OVER THE MTNS NORTH AND WEST OF THE CAPITAL REGION. A
COOLER AND DRIER AIR MASS WILL BE FILTERING IN FOR THE MID WEEK.
LOWS WILL BE IN THE MID AND U40S NORTH AND WEST OF THE CAPITAL
DISTRICT...AND LOWER TO M50S FROM THE CAPITAL DISTRICT SOUTH AND
EAST. TOTAL RAINFALL COULD BE IN THE QUARTER OF AN INCH TO INCH
RANGE BY WEDNESDAY MORNING...WITH SOME LOCATIONS GETTING A FEW
INCHES WHERE THE CONVECTION OCCURS.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
WEDNESDAY WILL BE A BRISK AND COOLER DAY IN WAKE OF THE LOW
PRESSURE SYSTEM WHICH WILL MOVE OFF TO OUR EAST TUESDAY NIGHT.
GUSTY WEST TO NORTHWEST WINDS WILL USHER IN A COOLER AIR MASS WITH
TEMPERATURES EXPECTED TO RUN AROUND 10 DEGREES BELOW
NORMAL....WITH A LARGE RANGE ACROSS THE FORECAST AREA FROM THE
LOWER 50S TO UPPER 60S. WITH CYCLONIC FLOW ACROSS THE REGION AND
COLD AIR ALOFT A PARTLY SUNNY TO MOSTLY CLOUDY DAY IS ANTICIPATED
WITH GREATER CLOUD COVER ACROSS THE HIGHER TERRAIN.

IT WILL FEEL CHILLY WEDNESDAY NIGHT WITH LOWS EXPECTED TO FALL INTO THE
MID 30S TO MID 40S...WHICH ARE NEAR SEASONABLE.

THE REGION WILL REMAIN ON THE SOUTHERN PERIPHERY OF THE LONGWAVE TROUGH
OVER EASTERN CANADA. THE FLOW ALOFT FOR THURSDAY IS EXPECTED TO BECOME
FAIRLY ZONAL WITH SOME HIGHER PRESSURE BUILDING IN AT THE SURFACE...SO
EXPECTING DRY WEATHER...LIGHTER WESTERLY WINDS AND NEAR SEASONABLE
TEMPERATURES.

A SHORT WAVE ROTATING ABOUT THE UPPER LOW THROUGH THE BASE OF THE
TROUGH FRIDAY SHOULD BRING A WEAK FRONTAL BOUNDARY AT LEAST THE NORTHERN
REACHES OF THE REGION. AT THIS TIME...MOISTURE ASSOCIATED WITH THE
BOUNDARY SHOULD BE LIMITED SO HAVE A FAIR WEATHER FORECAST.

AS WE HEAD INTO MEMORIAL DAY WEEKEND HIGH PRESSURE AT THE SURFACE AND
ALOFT ARE MODELED TO BUILD INTO THE REGION AND RESULT IN FAIR WEATHER
FOR SATURDAY AND HOPEFULLY ALL OF SUNDAY TOO. A LOW PRESSURE SYSTEM IS
MODELED TO BE MOVING INTO THE GREAT LAKES REGION. THE GFS IS STRONGER
WITH THIS SYSTEM THAN THE ECMWF WHICH COULD BEGIN TO AFFECT THE REGION
SUNDAY.

&&

.AVIATION /17Z SUNDAY THROUGH THURSDAY/...
A WEAK COLD FRONTAL BOUNDARY HAS MOVED SOUTH OF THE FA OVER
SOUTHEAST NY. IN ITS WAKE A LARGE RIDGE OF HIGH PRESSURE WAS
BUILDING SOUTHEAST FROM SOUTHERN ONTARIO. AS A RESULT SKIES FOR
THE REMAINDER OF THIS AFTERNOON INTO THE OVERNIGHT WILL BE MAINLY
SKC-SCT045 SCT250 WITH MORE IN THE WAY OF CLOUDS AT KPOU WHICH
WILL BE CLOSER TO THE FRONTAL BOUNDARY WITH BKN040 BKN060
EXPECTED.

MAINLY MOSTLY CLEAR SKIES ARE EXPECTED TONIGHT HOWEVER SOME
STRATUS MAY MOVE IN TOWARD SUNRISE WITH THE LIGHT ONSHORE FLOW OFF
THE ATLANTIC ESPECIALLY AT KPSF AND KPOU...OTHERWISE KALB AND KGFL
WILL BE MAINLY SCT250 MONDAY MORNING.

WINDS WILL BE GENERALLY VARIABLE AT 10 KTS OR LESS THIS
AFTERNOON...BECOMING LIGHT AND VARIABLE TONIGHT AND THEN S-SE AT
5-10 KTS ON MONDAY MORNING.

OUTLOOK...
MONDAY NIGHT: HIGH OPERATIONAL IMPACT. LIKELY SHRA...TSRA.
TUESDAY: HIGH OPERATIONAL IMPACT. LIKELY SHRA...TSRA.
TUESDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
WEDNESDAY: LOW OPERATIONAL IMPACT. BREEZY NO SIG WX.
WEDNESDAY NIGHT TO THURSDAY: NO OPERATIONAL IMPACT. NO SIG WX

&&

.FIRE WEATHER...
A COLD FRONT WILL DRIFT SOUTH OF THE REGION TODAY...AS
HIGH PRESSURE WILL BUILD IN FROM SOUTHEASTERN CANADA. THE FRONTAL
BOUNDARY WILL BE STATIONARY SOUTH OF EAST CENTRAL NEW YORK TONIGHT
INTO MONDAY BEFORE A LOW PRESSURE SYSTEM AND COLD FRONT APPROACHES
FROM THE GREAT LAKES REGION AND THE MIDWEST WITH INCREASING CHANCES
OF SHOWERS AND THUNDERSTORMS LATE MONDAY INTO TUESDAY.

THE RH VALUES WILL LOWER TO 25 TO 40 PERCENT THIS AFTERNOON...AND
THEN HAVE AN EXCELLENT RECOVERY TO 85 TO 100 PERCENT TONIGHT WITH
SOME DEW FORMATION. EXPECT THE RH VALUES TO LOWER TO 45 TO 60
PERCENT MONDAY AFTERNOON.

THE WINDS WILL BE FROM THE NORTH TO NORTHWEST AT 5 TO 15 MPH THIS
AFTERNOON...AND THEN LIGHT TO CALM TONIGHT. THE WINDS WILL BE FROM
THE SOUTHEAST TO SOUTH AT 5 TO 15 MPH ON MONDAY.

THE NEXT CHANCE OF A WIDESPREAD RAINFALL IN TERMS OF SHOWERS AND
THUNDERSTORMS WILL BE LATE MONDAY INTO TUESDAY.

&&

.HYDROLOGY...
NO WIDESPREAD HYDRO PROBLEMS ARE EXPECTED THE NEXT 5 DAYS.

DRY WEATHER WILL PERSIST TODAY INTO EARLY MONDAY. CHANCES OF
SHOWERS AND THUNDERSTORMS INCREASE LATE MONDAY AFTERNOON THROUGH
TUESDAY. MOST OF THE HYDRO SERVICE AREA COULD GET A QUARTER OF AN
INCH TO AN INCH OF RAINFALL...BUT LOCALLY HIGHER AMOUNTS ARE
POSSIBLE IN THUNDERSTORMS. DRY CONDITIONS WILL RETURN WED TO END
THE WEEK.

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...WASULA
NEAR TERM...BGM/11/WASULA
SHORT TERM...WASULA
LONG TERM...IAA
AVIATION...IAA/11
FIRE WEATHER...WASULA
HYDROLOGY...SNYDER/WASULA



AREA FORECAST DISCUSSION

NWS ALBANY NY

 1254 PM EDT SUN MAY 17 2015

.SYNOPSIS...
A COLD FRONT WILL DRIFT SOUTH OF THE REGION TODAY...AS
HIGH PRESSURE WILL BUILD IN FROM SOUTHEASTERN CANADA. THE FRONTAL
BOUNDARY WILL BE STATIONARY SOUTH OF EAST CENTRAL NEW YORK TONIGHT
INTO MONDAY BEFORE A LOW PRESSURE SYSTEM AND COLD FRONT APPROACHES
FROM THE GREAT LAKES REGION AND THE MIDWEST WITH INCREASING CHANCES
OF SHOWERS AND THUNDERSTORMS LATE MONDAY INTO TUESDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1230 PM EDT...MESOSCALE ANALYSIS REVEALS THE COLD FRONT HAS
STALLED ALONG OUR SOUTHERN PERIPHERY OF OUR CWFA. LAPS/SPC
ANALYSIS WINDOWS SUGGEST SBCAPES HAVE RISEN TO NEAR 1K J/KG.
HOWEVER...THE 12Z SOUNDINGS FROM KALB-KOKX...SHOW THE INVERSION
LAYER WAS BELOW -20C SO THE POTENTIAL FOR THUNDER LOOKS RATHER
LOW. HOWEVER...DPROG/DT OF THE HRRR REFLECTIVITY FORECASTS HAVE
SHOWN AN INCREASE OF ISOLATED SHOWERS SO WITH THIS UPDATE WE WILL
PLACE A SLIGHT CHANCE POPS FOR ULSTER/DUTCHESS/LITCHFIELD COUNTIES
WITH MAINLY THE SOUTHERN PORTIONS OF THESE COUNTIES. THE H2O VAPOR
LOOP DOES SHOW HINTS OF A WEAK SHORT WAVE OVER WESTERN NY WITH
RAP13/HRRR FORECASTS MOVING THIS FEATURE ACROSS THE SOUTHERN
PORTIONS OF THE REGION TO FURTHER SUPPORT THE SLIGHT CHANCE
UPGRADE FOR SHOWERS. OTHERWISE...A DELIGHTFUL END TO THE WEEKEND
WITH TEMPERATURES CLIMBING INTO THE LOWER HALF OF THE 80S WITH 70S
ACROSS THE HIGHER TERRAIN.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
TONIGHT...THE SFC CYCLONE DRIFTS N/NE OF UPSTATE NY OVER NRN
MAINE AND THE CANADIAN MARITIMES. THE MID-LEVEL RIDGE AXIS SETS UP
OVER ERN NY AND WRN NEW ENGLAND. A CLEAR/MOSTLY CLEAR AND COOL
NIGHT IS EXPECTED WITH SOME RADIATIONAL COOLING EXPECTED EARLY
ON. SOME STRATUS MAY START TO MOVE IN SOUTH OF MASS PIKE AND OVER
THE MID HUDSON VALLEY BTWN 09Z-12Z MONDAY MORNING. LOWS WILL
GENERALLY BE IN THE MID TO U50S FROM THE CAPITAL REGION...MOHAWK
VALLEY...AND BERKSHIRES SOUTH...AND M40S TO L50S TO THE NORTH.

MONDAY...A BACKDOOR COLD FRONT DRIFTS WESTWARD ACROSS THE
REGION...AND STALLS OVER CNTRL NY WITH THE SFC HIGH BUILDING IN
FROM THE GULF OF MAINE AND NEW BRUNSWICK. LOW PRESSURE UPSTREAM
OVER THE UPPER MIDWEST/WRN GREAT LAKES REGION WILL EDGE CLOSER
ASSOCIATED WITH A POSITIVELY TILTED UPPER TROUGH. A FEW ISOLATED
SHOWERS WILL BE POSSIBLE OVER WRN NEW ENGLAND AND THE HIGHER
TERRAIN OF EASTERN NY WITH THE BACKDOOR FRONT. IT WILL BE CLOUDY
AND COOLER THAN SUNDAY. A MID-LEVEL SHORT-WAVE IN THE SW
FLOW...AND THE BACKDOOR FRONT WILL TRY TO MOVE BACK EASTWARD AS A
WARM FRONT DURING THE MID TO LATE AFTERNOON TO INCREASE THE THREAT
OF SHOWERS AND PERHAPS SOME ISOLATED THUNDERSTORMS WEST OF THE
HUDSON VALLEY. HIGHS WILL ONLY BE IN THE MID 60S TO NEAR 70F OVER
WRN NEW ENGLAND. EXPECT U60S TO M70S OVER ERN NY.

MONDAY NIGHT...THE WARM FRONT OR PREFRONTAL THERMAL TROUGH TO THE
SYSTEM WILL SLOWLY MOVE ACROSS THE REGION. MOISTURE POOLS AHEAD OF
THE TROUGH WITH SFC DEWPTS RISING INTO THE 50S. THE LATEST
SHOWALTER VALUES LOWER TO 0 TO -1C WITH SOME MUCAPE. THE
INCREASING MOISTURE CONVERGENCE WITH RISING PWAT VALUE A FEW
STANDARD DEVIATIONS ABOVE NORMAL SHOULD ALLOW FOR A BAND OR BANDS
OF SHOWERS WITH EMBEDDED THUNDERSTORMS. INITIALLY THESE SHOWERS
AND STORMS WILL BE NORTH AND WEST OF THE CAPITAL DISTRICT PRIOR TO
06Z/TUE...AND THEN FROM THE CAPITAL DISTRICT SOUTH AND EAST BTWN
06Z- 12Z. POPS WERE KEPT IN THE LIKELY RANGE...EXCEPT HIGH CHC
FOR THE MID HUDSON VALLEY...SRN BERKS...AND NW CT. LOWS WILL BE OF
THE WET BULB VARIETY WITH M50S TO AROUND 60F.

TUESDAY...A HUMID AIR MASS WILL BE OVER THE REGION WITH LIMITED
INSOLATION DUE TO THE CLOUD COVER EARLY. IF THE CLOUDS
THIN...THEN MODEST AMOUNTS OF SFC BASED INSTABILITY IN THE
500-1000 J/KG RANGE MAY MATERIALIZE BASED ON THE GFS. LIFTED
INDICES IN THE -3C TO -5C RANGE WITH STRENGTHENING 0-6 KM BULK
SHEAR TO 30 TO 40 KTS BY 18Z/TUE...AND 40-50 KTS BY 00Z/WED. THE
MID LEVEL LAPSE RATES LOOK WEAK UNTIL THE NIGHT TIME PERIOD. SOME
DEEP ORGANIZED CONVECTION IS POSSIBLE...BUT WHETHER IT IS STRONG
TO SEVERE IS STILL A BIT UNCLEAR DUE TO POTENTIAL CLOUD
COVER...AND HOW MUCH INSTABILITY IS AVAILABLE. THE LATEST SPC DAY
3 CAME OUT WITH A MARGINAL THREAT FOR MOST OF THE REGION. THAT
SEEMS REASONABLE WITH THE APPROACHING FRONT AND PERHAPS AN
ISOLATED THREAT FOR A FEW SEVERE IF ANY ORGANIZED LINE GETS GOING.
PWATS WILL STILL BE IN THE INCH TO INCH A THIRD RANGE...AND SOME
LOCALLY HEAVY RAINFALL WILL BE POSSIBLE. HIGHS WILL BE IN THE
70-75F RANGE IN THE VALLEY AREAS...AND M60S TO NEAR 70F OVER THE
MTNS.

TUESDAY NIGHT...THE SFC COLD FRONT MOVES THROUGH...AND THE UPPER
LEVEL TROUGH AXIS WILL BE FOLLOWING IT. THE BEST CHC OF SHOWERS
WILL BE OVER THE MTNS NORTH AND WEST OF THE CAPITAL REGION. A
COOLER AND DRIER AIR MASS WILL BE FILTERING IN FOR THE MID WEEK.
LOWS WILL BE IN THE MID AND U40S NORTH AND WEST OF THE CAPITAL
DISTRICT...AND LOWER TO M50S FROM THE CAPITAL DISTRICT SOUTH AND
EAST. TOTAL RAINFALL COULD BE IN THE QUARTER OF AN INCH TO INCH
RANGE BY WEDNESDAY MORNING...WITH SOME LOCATIONS GETTING A FEW
INCHES WHERE THE CONVECTION OCCURS.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
WEDNESDAY WILL BE A BRISK AND COOLER DAY IN WAKE OF THE LOW
PRESSURE SYSTEM WHICH WILL MOVE OFF TO OUR EAST TUESDAY NIGHT.
GUSTY WEST TO NORTHWEST WINDS WILL USHER IN A COOLER AIR MASS WITH
TEMPERATURES EXPECTED TO RUN AROUND 10 DEGREES BELOW
NORMAL....WITH A LARGE RANGE ACROSS THE FORECAST AREA FROM THE
LOWER 50S TO UPPER 60S. WITH CYCLONIC FLOW ACROSS THE REGION AND
COLD AIR ALOFT A PARTLY SUNNY TO MOSTLY CLOUDY DAY IS ANTICIPATED
WITH GREATER CLOUD COVER ACROSS THE HIGHER TERRAIN.

IT WILL FEEL CHILLY WEDNESDAY NIGHT WITH LOWS EXPECTED TO FALL INTO THE
MID 30S TO MID 40S...WHICH ARE NEAR SEASONABLE.

THE REGION WILL REMAIN ON THE SOUTHERN PERIPHERY OF THE LONGWAVE TROUGH
OVER EASTERN CANADA. THE FLOW ALOFT FOR THURSDAY IS EXPECTED TO BECOME
FAIRLY ZONAL WITH SOME HIGHER PRESSURE BUILDING IN AT THE SURFACE...SO
EXPECTING DRY WEATHER...LIGHTER WESTERLY WINDS AND NEAR SEASONABLE
TEMPERATURES.

A SHORT WAVE ROTATING ABOUT THE UPPER LOW THROUGH THE BASE OF THE
TROUGH FRIDAY SHOULD BRING A WEAK FRONTAL BOUNDARY AT LEAST THE NORTHERN
REACHES OF THE REGION. AT THIS TIME...MOISTURE ASSOCIATED WITH THE
BOUNDARY SHOULD BE LIMITED SO HAVE A FAIR WEATHER FORECAST.

AS WE HEAD INTO MEMORIAL DAY WEEKEND HIGH PRESSURE AT THE SURFACE AND
ALOFT ARE MODELED TO BUILD INTO THE REGION AND RESULT IN FAIR WEATHER
FOR SATURDAY AND HOPEFULLY ALL OF SUNDAY TOO. A LOW PRESSURE SYSTEM IS
MODELED TO BE MOVING INTO THE GREAT LAKES REGION. THE GFS IS STRONGER
WITH THIS SYSTEM THAN THE ECMWF WHICH COULD BEGIN TO AFFECT THE REGION
SUNDAY.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
A WEAK COLD FRONTAL BOUNDARY HAS MOVED ACROSS THE LOCAL AREA.
THE FLOW ALOFT WILL CAUSE THIS BOUNDARY STALL IN THE VICINITY
OF THE NY/PA BORDER TODAY. THE SHORT WAVE TROUGH WILL CONTINUE TO
MOVE SOUTHEASTWARD DOWN THE EAST SIDE OF THE RIDGE AXIS TODAY
AWAY FORM THE LOCAL AREA AND THE UPPER RIDGE WILL STRENGTHEN.
THE RIDGE AXIS INITIALLY TO OUR WEST WILL SHIFT EAST AND ACROSS
THE REGION TONIGHT.

HAVE HAD VARIABLE CLOUDY SKIES ACROSS AREA AND WITH CALM WINDS
AND WET GROUND WHERE SKIES HAVE CLEARED OUT FOR ANY PERIOD OF TIME
IFR-MVFR FOG DEVELOPED. THE ATMOSPHERE WILL MIX AND THE FOG WILL
BURN OFF. CLOUD COVER WILL DECREASE TODAY. MAINLY MOSTLY CLEAR SKIES
ARE EXPECTED TONIGHT HOWEVER SOME STRATUS MAY MOVE IN TOWARD SUNRISE
WITH THE LIGHT ONSHORE FLOW OFF THE ATLANTIC.

LIGHT AND VARIABLE TO CALM WINDS OVERNIGHT BECOMING WEST TO NORTHWEST
AT LESS THAN 10 KNOTS. THE EXCEPTION WILL BE AT KGFL WHERE THE
FLOW IS EXPECTED TO BE NORTHEASTERLY.

OUTLOOK...
MONDAY NIGHT: HIGH OPERATIONAL IMPACT. LIKELY SHRA...TSRA.
TUESDAY: HIGH OPERATIONAL IMPACT. LIKELY SHRA...TSRA.
TUESDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
WEDNESDAY: LOW OPERATIONAL IMPACT. BREEZY NO SIG WX.
WEDNESDAY NIGHT TO THURSDAY: NO OPERATIONAL IMPACT. NO SIG WX

&&

.FIRE WEATHER...
A COLD FRONT WILL DRIFT SOUTH OF THE REGION TODAY...AS
HIGH PRESSURE WILL BUILD IN FROM SOUTHEASTERN CANADA. THE FRONTAL
BOUNDARY WILL BE STATIONARY SOUTH OF EAST CENTRAL NEW YORK TONIGHT
INTO MONDAY BEFORE A LOW PRESSURE SYSTEM AND COLD FRONT APPROACHES
FROM THE GREAT LAKES REGION AND THE MIDWEST WITH INCREASING CHANCES
OF SHOWERS AND THUNDERSTORMS LATE MONDAY INTO TUESDAY.

THE RH VALUES WILL LOWER TO 25 TO 40 PERCENT THIS AFTERNOON...AND
THEN HAVE AN EXCELLENT RECOVERY TO 85 TO 100 PERCENT TONIGHT WITH
SOME DEW FORMATION. EXPECT THE RH VALUES TO LOWER TO 45 TO 60
PERCENT MONDAY AFTERNOON.

THE WINDS WILL BE FROM THE NORTH TO NORTHWEST AT 5 TO 15 MPH THIS
AFTERNOON...AND THEN LIGHT TO CALM TONIGHT. THE WINDS WILL BE FROM
THE SOUTHEAST TO SOUTH AT 5 TO 15 MPH ON MONDAY.

THE NEXT CHANCE OF A WIDESPREAD RAINFALL IN TERMS OF SHOWERS AND
THUNDERSTORMS WILL BE LATE MONDAY INTO TUESDAY.

&&

.HYDROLOGY...
NO WIDESPREAD HYDRO PROBLEMS ARE EXPECTED THE NEXT 5 DAYS.

DRY WEATHER WILL PERSIST TODAY INTO EARLY MONDAY. CHANCES OF
SHOWERS AND THUNDERSTORMS INCREASE LATE MONDAY AFTERNOON THROUGH
TUESDAY. MOST OF THE HYDRO SERVICE AREA COULD GET A QUARTER OF AN
INCH TO AN INCH OF RAINFALL...BUT LOCALLY HIGHER AMOUNTS ARE
POSSIBLE IN THUNDERSTORMS. DRY CONDITIONS WILL RETURN WED TO END
THE WEEK.

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...WASULA
NEAR TERM...BGM/11/WASULA
SHORT TERM...WASULA
LONG TERM...IAA
AVIATION...IAA
FIRE WEATHER...WASULA
HYDROLOGY...SNYDER/WASULA

FOR THE LATEST UPDATES...PLEASE VISIT OUR WEBPAGE AT
WWW.WEATHER.GOV/ALBANY




AREA FORECAST DISCUSSION

NWS NEW YORK NY

 1241 PM EDT SUN MAY 17 2015

.SYNOPSIS...
A BACKDOOR COLD FRONT APPROACHES FROM THE NORTH THIS
AFTERNOON...THEN DROPS SOUTHWEST ACROSS THE AREA TONIGHT. THE
FRONT STALLS JUST SOUTHWEST OF THE REGION ON MONDAY WITH HIGH
PRESSURE BUILDING IN FROM THE NORTHEAST. THIS FRONT WILL LIFT
THROUGH AS A WARM FRONT TUESDAY MORNING...FOLLOWED BY A COLD
FRONTAL PASSAGE TUESDAY EVENING. HIGH PRESSURE IS THEN IN CONTROL
INTO NEXT WEEKEND...WITH THE EXCEPTION OF A WEAK COLD FRONTAL
PASSAGE ON FRIDAY

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LOOKING AT DEVELOPING CUMULUS FIELD ON SATELLITE OVER THE LOWER
HUDSON VALLEY/NE NJ...SO AT THIS POINT HAVE NO REASON TO NOT
BELIEVE HRRR IDEA OF ISOLATED SHOWERS DEVELOPING THERE THIS
AFTERNOON.

WHILE ANY SHRA...WITH VERY LOW CHANCE OF A TSTM...WILL BE OF THE
HIT AND MISS VARIETY...GIVEN LIGHT WINDS ALOFT WILL BE SLOW TO
MOVE...SO COULD PRODUCE LOCALLY HEAVY RAINFALL. ONCE AGAIN...FAR
MORE LIKELY FOR A MISS THAN A HIT ON A SHRA AT ANY GIVEN LOCATION
OVER THE LOWER HUDSON VALLEY/NE NJ/NYC THIS AFTERNOON.

MADE MINOR CHANGES TO TEMPERATURES THIS UPDATE WITH VALUES
EXPECTED TO BE AROUND 10-15 DEGREES ABOVE NORMAL AS A RESULT.

SEABREEZES HAVE DEVELOPED A TAD AHEAD OF SCHEDULE...BUT BASED ON
LATEST TRENDS SHOULD BE SLOW TO MOVE INLAND...ESPECIALLY ACROSS
LONG ISLAND/NYC.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
UPPER LEVEL RIDGE AXIS BUILDS EAST ACROSS NEW ENGLAND
TONIGHT...WHICH IN TURN STRENGTHENS HIGH PRESSURE OVER THE
CANADIAN MARITIMES AND SENDS A BACKDOOR COLD ACROSS THE AREA BY
DAYBREAK. THE FRONT WILL STALL JUST SOUTHWEST OF THE FORECAST
AREA ON MON. HOWEVER..DUE TO THE CLOSE PROXIMITY OF THE BOUNDARY
CAN NOT RULE OUT SHOWERS...PRIMARILY FROM NYC AND POINTS WEST.
CLOUDS MOVE IN BEHIND THE COLD FRONT LATE TONIGHT AS A MOIST E
FLOW DEVELOPS ACROSS THE REGION. SOME CLEARING IS POSSIBLE MON
AFTERNOON ACROSS EASTERN LONG ISLAND/SE CT...WITH A MOSTLY CLOUDY
SKY FURTHER WEST.

LOWS TONIGHT WILL REMAIN MILD WITH THE CLOUD COVER AND DEVELOPING
EAST FLOW...HOWEVER...FOR THOSE SAME REASONS WILL BE ABOUT 5
DEGREES BELOW NORMAL ON MON.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
MODELS ARE IN GOOD AGREEMENT WITH THE H5 PATTERN THROUGH THE MIDDLE
OF NEXT WEEK. A VORTEX DEVELOPS OVER SE CANADA AT THE END OF THE
WEEK WITH ZONAL FLOW BECOMING SW ALOFT AS A PIECE OF ENERGY MOVING
AROUND THE BASE RESULTS IN AMPLIFICATION.

WARM FRONT LIFTS THROUGH TUE MORNING FOLLOWED BY A COLD FRONT IN
THE EVE WITH A BETTER CHANCE FOR WIDESPREAD SHOWERS/TSTMS. HIGH
PRESSURE THEN BUILDS IN FROM THE W AND REMAINS IN CONTROL THROUGH
THE END OF THE WEEK...WITH THE EXCEPTION OF MAYBE A SHOWER
ASSOCIATED WITH A WEAK COLD FRONT DROPPING THROUGH THE AREA ON FRI
AFTERNOON/EVE.

TEMPERATURES WILL GENERALLY BE ABOVE NORMAL LEVELS THROUGH THE
PERIOD.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
A COLD FRONT APPROACHES FROM THE NORTH TODAY...AND MOVES THROUGH
THE REGION LATE TONIGHT INTO MONDAY MORNING.

CONDITIONS CONTINUE TO SLOWLY IMPROVE WITH SOME LINGERING STRATUS
AT KISP/KHPN/KTEB THROUGH 16Z. A BRIEF PERIOD OF MVFR CIGS 015 TO
020 IS POSSIBLE OVER THE CITY TERMINALS THROUGH 16Z.
OTHERWISE...VFR IS EXPECTED AFTER 16Z AT ALL TERMINALS.

WITH LIGHT FLOW OVER THE AREA...WINDS HAVE VARIED. NNW-NNE WINDS
OVER CITY TERMINALS AND KHPN/KISP UNDER 10 KT WILL BECOME SW
AROUND 10 KT THIS AFTERNOON. COASTAL TERMINALS WILL BECOME SOUTH
DUE TO AFTERNOON SEA BREEZES.

WINDS DIMINISH TO 5 KT OR LESS AFT 02Z MONDAY.

FOG/STRATUS LIKELY AGAIN LATE TONIGHT THROUGH MONDAY MORNING.

.OUTLOOK FOR 12Z MONDAY THROUGH THURSDAY...
.MONDAY...IFR OR LOWER IN FOG/STRATUS IN THE MORNING...THEN
PATCHY MVFR CIGS IN THE AFTERNOON. E-NE WINDS 10-15 KT.
.LATE MONDAY NIGHT-TUESDAY EVENING...MVFR OR LOWER POSSIBLE IN
FOG/STRATUS AND/OR SHRA/TSTM.
.LATE TUESDAY NIGHT-THURSDAY...VFR. NW WINDS G20+KT POSSIBLE.

&&

.MARINE...
MADE MINOR CHANGES THIS UPDATE TO REFLECT THE LATEST TRENDS IN
OBSERVATIONS AND GUIDANCE. THE FORECAST APPEARS ON TRACK.

A BACKDOOR COLD FRONT APPROACHES THE WATERS FROM THE NORTH THIS
AFTERNOON AND PASSES TO SOUTH OF THE WATERS BY EARLY MONDAY
MORNING. THE PRESSURE GRADIENT GRADUALLY TIGHTENS AS HIGH PRES
BUILDS ALONG THE NEW ENGLAND COAST AND A COLD FRONT APPROACHES
FROM THE WEST. THAT FRONT MOVES ACROSS THE WATERS LATE
TUESDAY...AND THEN HIGH PRES RETURNS FOR THE MIDDLE OF THE WEEK.

SUB-SMALL CRAFT ADVISORY CONDITIONS ON TAP THROUGH MONDAY...AND
THEN SCA CONDITIONS EXPECTED ON WEDNESDAY BEHIND THE DEPARTING
COLD FRONT.

&&

.HYDROLOGY...
GENERALLY LIGHT RAINFALL AMOUNTS ARE POSSIBLE IN ANY SHOWERS THE
NEXT COUPLE OF DAYS...MAINLY WEST OF NYC.

HOWEVER...ANY SHOWERS WHICH DO FORM THIS AFTERNOON WILL BE VERY
SLOW TO MOVE. IF ANY STRONGER CONVECTION WERE TO FORM OVER A
LOCATION...THERE WOULD BE THE POTENTIAL FOR THE PONDING OF WATER
ON ROADWAYS AND POSSIBLY MINOR POOR DRAINAGE FLOODING DEPENDING ON
THE EXACT DURATION AND STRENGTH OF ANY GIVEN SHOWER WHICH MIGHT
FORM.

AROUND 1/4 OF AN INCH OF RAINFALL IS POSSIBLE WITH THE FRONTAL
SYSTEM ON TUE.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.

&&

$$

SYNOPSIS...MALOIT/DW
NEAR TERM...MALOIT/DW
SHORT TERM...DW
LONG TERM...DW/24
AVIATION...DS/MPS
MARINE...MALOIT/MPS
HYDROLOGY...MALOIT/DW




AREA FORECAST DISCUSSION

NWS NEW YORK NY

 1038 AM EDT SUN MAY 17 2015

.SYNOPSIS...
A DISSIPATING FRONTAL BOUNDARY OR TROUGH WILL MOVE ACROSS THE
AREA THIS MORNING BEFORE WASHING OUT. A BACKDOOR COLD FRONT WILL
THEN DROP SOUTHWEST ACROSS NEW ENGLAND TONIGHT AND ACROSS THE AREA
BY DAYBREAK MONDAY. THE FRONT STALLS JUST SOUTHWEST OF THE REGION
ON MONDAY WITH HIGH PRESSURE BUILDING IN FROM THE NORTHEAST. THIS
FRONT WILL LIFT THROUGH AS A WARM FRONT TUESDAY MORNING...FOLLOWED
BY A COLD FRONTAL PASSAGE TUESDAY EVENING. HIGH PRESSURE IS THEN
IN CONTROL INTO NEXT WEEKEND...WITH THE EXCEPTION OF A WEAK COLD
FRONTAL PASSAGE ON FRIDAY

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SOME COMPETING FEATURES ALOFT...WITH RIDGING BUILDING IN FROM THE
WEST FROM 850-500 HPA...SO WILL HAVE SUBSIDENCE ASSOCIATED WITH
THAT. AT THE SAME TIME ALL HI-RES MODELS SHOW WEAK SHORTWAVE GOING
OVER THE TOP OF THE RIDGE AND PASSING THIS AFTERNOON. NOTING HAVE
WARMED FASTER THAN FORECAST...ESPECIALLY OVER WESTERN
ZONES...SHOULD HAVE A BIT MORE LOW LEVEL INSTABILITY TO WORK WITH
THAN PREVIOUSLY THOUGHT. ALSO BASED ON THIS HAVE TWEAKED HIGHS UP
A COUPLE DEGREES AT MOST LOCATIONS...GENERALLY CONSISTENT WITH A
BLEND OF MAV/MET GUIDANCE WITH NAM 2-METER TEMPERATURES. EXPECT
HIGHS TO BE AROUND 10-15 DEGREES ABOVE NORMAL AS A RESULT.

BASED ON THIS AND HRRR HAVE INCREASED AREA WITH SLIGHT CHANCE POPS
THIS AFTERNOON TO COVER ENTIRE LOWER HUDSON VALLEY/NE NJ/NYC.
WHILE ANY SHRA...WITH VERY LOW CHANCE OF A TSTM...WILL BE OF THE
HIT AND MISS VARIETY...GIVEN LIGHT WINDS ALOFT WILL BE SLOW TO
MOVE...SO COULD PRODUCE LOCALLY HEAVY RAINFALL. ONCE AGAIN...FAR
MORE LIKELY FOR A MISS THAN A HIT ON A SHRA AT ANY GIVEN LOCATION
OVER THE LOWER HUDSON VALLEY/NE NJ/NYC THIS AFTERNOON.

A WEAK W/SW FLOW WILL GIVE WAY TO SEABREEZES THIS AFTERNOON.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
UPPER LEVEL RIDGE AXIS BUILDS EAST ACROSS NEW ENGLAND
TONIGHT...WHICH IN TURN STRENGTHENS HIGH PRESSURE OVER THE
CANADIAN MARITIMES AND SENDS A BACKDOOR COLD ACROSS THE AREA BY
DAYBREAK. THE FRONT WILL STALL JUST SOUTHWEST OF THE FORECAST
AREA ON MON. HOWEVER..DUE TO THE CLOSE PROXIMITY OF THE BOUNDARY
CAN NOT RULE OUT SHOWERS...PRIMARILY FROM NYC AND POINTS WEST.
CLOUDS MOVE IN BEHIND THE COLD FRONT LATE TONIGHT AS A MOIST E
FLOW DEVELOPS ACROSS THE REGION. SOME CLEARING IS POSSIBLE MON
AFTERNOON ACROSS EASTERN LONG ISLAND/SE CT...WITH A MOSTLY CLOUDY
SKY FURTHER WEST.

LOWS TONIGHT WILL REMAIN MILD WITH THE CLOUD COVER AND DEVELOPING
EAST FLOW...HOWEVER...FOR THOSE SAME REASONS WILL BE ABOUT 5
DEGREES BELOW NORMAL ON MON.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
MODELS ARE IN GOOD AGREEMENT WITH THE H5 PATTERN THROUGH THE MIDDLE
OF NEXT WEEK. A VORTEX DEVELOPS OVER SE CANADA AT THE END OF THE
WEEK WITH ZONAL FLOW BECOMING SW ALOFT AS A PIECE OF ENERGY MOVING
AROUND THE BASE RESULTS IN AMPLIFICATION.

WARM FRONT LIFTS THROUGH TUE MORNING FOLLOWED BY A COLD FRONT IN
THE EVE WITH A BETTER CHANCE FOR WIDESPREAD SHOWERS/TSTMS. HIGH
PRESSURE THEN BUILDS IN FROM THE W AND REMAINS IN CONTROL THROUGH
THE END OF THE WEEK...WITH THE EXCEPTION OF MAYBE A SHOWER
ASSOCIATED WITH A WEAK COLD FRONT DROPPING THROUGH THE AREA ON FRI
AFTERNOON/EVE.

TEMPERATURES WILL GENERALLY BE ABOVE NORMAL LEVELS THROUGH THE
PERIOD.

&&

.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
A COLD FRONT APPROACHES FROM THE NORTH TODAY...AND MOVES THROUGH
THE REGION LATE TONIGHT INTO MONDAY MORNING.

CONDITIONS CONTINUE TO SLOWLY IMPROVE WITH SOME LINGERING STRATUS
AT KISP/KHPN/KTEB THROUGH 16Z. A BRIEF PERIOD OF MVFR CIGS 015 TO
020 IS POSSIBLE OVER THE CITY TERMINALS THROUGH 16Z.
OTHERWISE...VFR IS EXPECTED AFTER 16Z AT ALL TERMINALS.

WITH LIGHT FLOW OVER THE AREA...WINDS HAVE VARIED. NNW-NNE WINDS
OVER CITY TERMINALS AND KHPN/KISP UNDER 10 KT WILL BECOME SW
AROUND 10 KT THIS AFTERNOON. COASTAL TERMINALS WILL BECOME SOUTH
DUE TO AFTERNOON SEA BREEZES.

WINDS DIMINISH TO 5 KT OR LESS AFT 02Z MONDAY.

FOG/STRATUS LIKELY AGAIN LATE TONIGHT THROUGH MONDAY MORNING.

.OUTLOOK FOR 12Z MONDAY THROUGH THURSDAY...
.MONDAY...IFR OR LOWER IN FOG/STRATUS IN THE MORNING...THEN
PATCHY MVFR CIGS IN THE AFTERNOON. E-NE WINDS 10-15 KT.
.LATE MONDAY NIGHT-TUESDAY EVENING...MVFR OR LOWER POSSIBLE IN
FOG/STRATUS AND/OR SHRA/TSTM.
.LATE TUESDAY NIGHT-THURSDAY...VFR. NW WINDS G20+KT POSSIBLE.

&&

.MARINE...
A BACKDOOR COLD FRONT APPROACHES THE WATERS FROM THE NORTH LATER
TODAY AND PASSES SOUTH OF THE WATERS MONDAY MORNING. THE PRESSURE
GRADIENT GRADUALLY TIGHTENS AS HIGH PRES BUILDS ALONG THE NEW
ENGLAND COAST AND A COLD FRONT APPROACHES FROM THE WEST. THAT
FRONT MOVES ACROSS THE WATERS LATE TUESDAY...AND THEN HIGH PRES
RETURNS FOR THE MIDDLE OF THE WEEK.

SUB-SMALL CRAFT ADVISORY CONDITIONS ON TAP THROUGH MONDAY...AND
THEN SCA CONDITIONS EXPECTED ON WEDNESDAY BEHIND THE DEPARTING
COLD FRONT.

&&

.HYDROLOGY...
GENERALLY LIGHT RAINFALL AMOUNTS ARE POSSIBLE IN ANY SHOWERS THE
NEXT COUPLE OF DAYS...MAINLY WEST OF NYC.

HOWEVER...ANY SHOWERS WHICH DO FORM THIS AFTERNOON WILL BE VERY
SLOW TO MOVE. IF ANY STRONGER CONVECTION WERE TO FORM OVER A
LOCATION...THERE WOULD BE THE POTENTIAL FOR THE PONDING OF WATER
ON ROADWAYS AND POSSIBLY MINOR POOR DRAINAGE FLOODING DEPENDING ON
THE EXACT DURATION AND STRENGTH OF ANY GIVEN SHOWER WHICH MIGHT
FORM.

AROUND 1/4 OF AN INCH OF RAINFALL IS POSSIBLE WITH THE FRONTAL
SYSTEM ON TUE.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...DW
NEAR TERM...MALOIT/DW
SHORT TERM...DW
LONG TERM...24/DW
AVIATION...MPS/DS
MARINE...MALOIT/MPS
HYDROLOGY...DW




AREA FORECAST DISCUSSION

NWS NEW YORK NY

 1008 AM EDT SUN MAY 17 2015

.SYNOPSIS...
A DISSIPATING FRONTAL BOUNDARY OR TROUGH WILL MOVE ACROSS THE
AREA THIS MORNING BEFORE WASHING OUT. A BACKDOOR COLD FRONT WILL
THEN DROP SOUTHWEST ACROSS NEW ENGLAND TONIGHT AND ACROSS THE AREA
BY DAYBREAK MONDAY. THE FRONT STALLS JUST SOUTHWEST OF THE REGION
ON MONDAY WITH HIGH PRESSURE BUILDING IN FROM THE NORTHEAST. THIS
FRONT WILL LIFT THROUGH AS A WARM FRONT TUESDAY MORNING...FOLLOWED
BY A COLD FRONTAL PASSAGE TUESDAY EVENING. HIGH PRESSURE IS THEN
IN CONTROL INTO NEXT WEEKEND...WITH THE EXCEPTION OF A WEAK COLD
FRONTAL PASSAGE ON FRIDAY

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SOME COMPETING FEATURES ALOFT...WITH RIDGING BUILDING IN FROM THE
WEST FROM 850-500 HPA...SO WILL HAVE SUBSIDENCE ASSOCIATED WITH
THAT. AT THE SAME TIME ALL HI-RES MODELS SHOW WEAK SHORTWAVE GOING
OVER THE TOP OF THE RIDGE AND PASSING THIS AFTERNOON. NOTING HAVE
WARMED FASTER THAN FORECAST...ESPECIALLY OVER WESTERN
ZONES...SHOULD HAVE A BIT MORE LOW LEVEL INSTABILITY TO WORK WITH
THAN PREVIOUSLY THOUGHT. ALSO BASED ON THIS HAVE TWEAKED HIGHS UP
A COUPLE DEGREES AT MOST LOCATIONS...GENERALLY CONSISTENT WITH A
BLEND OF MAV/MET GUIDANCE WITH NAM 2-METER TEMPERATURES. EXPECT
HIGHS TO BE AROUND 10-15 DEGREES ABOVE NORMAL AS A RESULT.

BASED ON THIS AND HRRR HAVE INCREASED AREA WITH SLIGHT CHANCE POPS
THIS AFTERNOON TO COVER ENTIRE LOWER HUDSON VALLEY/NE NJ/NYC.
WHILE ANY SHRA...WITH VERY LOW CHANCE OF A TSTM...WILL BE OF THE
HIT AND MISS VARIETY...GIVEN LIGHT WINDS ALOFT WILL BE SLOW TO
MOVE...SO COULD PRODUCE LOCALLY HEAVY RAINFALL. ONCE AGAIN...FAR
MORE LIKELY FOR A MISS THAN A HIT ON A SHRA AT ANY GIVEN LOCATION
OVER THE LOWER HUDSON VALLEY/NE NJ/NYC THIS AFTERNOON.

A WEAK W/SW FLOW WILL GIVE WAY TO SEABREEZES THIS AFTERNOON.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
UPPER LEVEL RIDGE AXIS BUILDS EAST ACROSS NEW ENGLAND
TONIGHT...WHICH IN TURN STRENGTHENS HIGH PRESSURE OVER THE
CANADIAN MARITIMES AND SENDS A BACKDOOR COLD ACROSS THE AREA BY
DAYBREAK. THE FRONT WILL STALL JUST SOUTHWEST OF THE FORECAST
AREA ON MON. HOWEVER..DUE TO THE CLOSE PROXIMITY OF THE BOUNDARY
CAN NOT RULE OUT SHOWERS...PRIMARILY FROM NYC AND POINTS WEST.
CLOUDS MOVE IN BEHIND THE COLD FRONT LATE TONIGHT AS A MOIST E
FLOW DEVELOPS ACROSS THE REGION. SOME CLEARING IS POSSIBLE MON
AFTERNOON ACROSS EASTERN LONG ISLAND/SE CT...WITH A MOSTLY CLOUDY
SKY FURTHER WEST.

LOWS TONIGHT WILL REMAIN MILD WITH THE CLOUD COVER AND DEVELOPING
EAST FLOW...HOWEVER...FOR THOSE SAME REASONS WILL BE ABOUT 5
DEGREES BELOW NORMAL ON MON.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
MODELS ARE IN GOOD AGREEMENT WITH THE H5 PATTERN THROUGH THE MIDDLE
OF NEXT WEEK. A VORTEX DEVELOPS OVER SE CANADA AT THE END OF THE
WEEK WITH ZONAL FLOW BECOMING SW ALOFT AS A PIECE OF ENERGY MOVING
AROUND THE BASE RESULTS IN AMPLIFICATION.

WARM FRONT LIFTS THROUGH TUE MORNING FOLLOWED BY A COLD FRONT IN
THE EVE WITH A BETTER CHANCE FOR WIDESPREAD SHOWERS/TSTMS. HIGH
PRESSURE THEN BUILDS IN FROM THE W AND REMAINS IN CONTROL THROUGH
THE END OF THE WEEK...WITH THE EXCEPTION OF MAYBE A SHOWER
ASSOCIATED WITH A WEAK COLD FRONT DROPPING THROUGH THE AREA ON FRI
AFTERNOON/EVE.

TEMPERATURES WILL GENERALLY BE ABOVE NORMAL LEVELS THROUGH THE
PERIOD.

&&

.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
A BACKDOOR COLD FRONT APPROACHES FROM THE NORTH AND SINKS TO THE
SOUTH LATER TODAY...AND MOVES THROUGH THE REGION MONDAY MORNING.

FOG/STRATUS ACROSS THE AREA THROUGH 13-15Z. CONDITIONS LIFTING TO
MVFR...BUT ALSO SOME PATCHY IFR/LIFR CONDITIONS LINGER. VFR BY
15Z.

LIGHT/VRB WINDS THROUGH LATE MORNING...THEN GENERALLY SW WINDS
5-10 KT...BECOMING SOUTH AT COASTAL TERMINALS DUE TO AFTERNOON SEA
BREEZES.

WINDS DIMINISH TO 5 KT OR LESS AFT 02Z MONDAY.

FOG/STRATUS LIKELY AGAIN LATE TONIGHT THROUGH MONDAY MORNING.

.OUTLOOK FOR 12Z MONDAY THROUGH THURSDAY...
.MONDAY...IFR OR LOWER IN FOG/STRATUS IN THE MORNING...THEN
PATCHY MVFR CIGS IN THE AFTERNOON. E-NE WINDS 10-15 KT.
.LATE MONDAY NIGHT-TUESDAY EVENING...MVFR OR LOWER POSSIBLE IN
FOG/STRATUS AND/OR SHRA/TSTM.
.LATE TUESDAY NIGHT-THURSDAY...VFR. NW WINDS G20+KT POSSIBLE.

&&

.MARINE...
A BACKDOOR COLD FRONT APPROACHES THE WATERS FROM THE NORTH LATER
TODAY AND PASSES SOUTH OF THE WATERS MONDAY MORNING. THE PRESSURE
GRADIENT GRADUALLY TIGHTENS AS HIGH PRES BUILDS ALONG THE NEW
ENGLAND COAST AND A COLD FRONT APPROACHES FROM THE WEST. THAT
FRONT MOVES ACROSS THE WATERS LATE TUESDAY...AND THEN HIGH PRES
RETURNS FOR THE MIDDLE OF THE WEEK.

SUB-SMALL CRAFT ADVISORY CONDITIONS ON TAP THROUGH MONDAY...AND
THEN SCA CONDITIONS EXPECTED ON WEDNESDAY BEHIND THE DEPARTING
COLD FRONT.

&&

.HYDROLOGY...
GENERALLY LIGHT RAINFALL AMOUNTS ARE POSSIBLE IN ANY SHOWERS THE
NEXT COUPLE OF DAYS...MAINLY WEST OF NYC.

HOWEVER...ANY SHOWERS WHICH DO FORM THIS AFTERNOON WILL BE VERY
SLOW TO MOVE. IF ANY STRONGER CONVECTION WERE TO FORM OVER A
LOCATION...THERE WOULD BE THE POTENTIAL FOR THE PONDING OF WATER
ON ROADWAYS AND POSSIBLY MINOR POOR DRAINAGE FLOODING DEPENDING ON
THE EXACT DURATION AND STRENGTH OF ANY GIVEN SHOWER WHICH MIGHT
FORM.

AROUND 1/4 OF AN INCH OF RAINFALL IS POSSIBLE WITH THE FRONTAL
SYSTEM ON TUE.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...DW
NEAR TERM...MALOIT/DW
SHORT TERM...DW
LONG TERM...24/DW
AVIATION...MPS
MARINE...MALOIT/MPS
HYDROLOGY...DW




AREA FORECAST DISCUSSION

NWS NEW YORK NY

 142 AM EDT SUN MAY 17 2015

.SYNOPSIS...
A TROUGH OF LOW PRESSURE APPROACHES FROM THE WEST...LINGERING
NEARBY ON SUNDAY. A BACKDOOR COLD FRONT MOVES THROUGH SUNDAY
NIGHT. THE FRONT STALLS JUST SOUTHWEST OF THE REGION ON MONDAY
WITH HIGH PRESSURE BUILDING IN FROM THE NORTHEAST. THIS FRONT WILL
LIFT THROUGH AS A WARM FRONT TUESDAY MORNING...FOLLOWED BY A COLD
FRONT ON TUESDAY. HIGH PRESSURE IS THEN IN CONTROL INTO NEXT
WEEKEND...WITH THE EXCEPTION OF A WEAK COLD FRONTAL PASSAGE ON
FRIDAY

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
UPDATED TEMPS/DEW POINTS. ADDED PATCHY FOG PER LATEST NARRE PROB
FOR VSBY LESS THAN 1 MILE. THIS MAKES SENSE DUE TO LINGERING LOW
LEVEL MOISTURE AND LIGHT WINDS...WITH GOOD COVERAGE FOR
SHOWERS/TSTMS.

MOST MESOSCALE MODELS...INCLUDING HRRR WHICH HAS BEEN GOOD FROM
RUN TO RUN...INDICATES CONVECTION CONTINUING THROUGH MIDNIGHT...
THEN DIMINISHING IN COVERAGE LATER TONIGHT. UPDATES THIS EVENING
BASED ON THESE TRENDS...AND ANALYSIS.

HIGH PW VALUES WILL ALSO MEAN THERE IS THE POTENTIAL FOR BRIEF HEAVY
DOWNPOURS IN ANY STORM. MINOR URBAN FLOODING REMAINS A
POSSIBILITY...BUT SHOULD BE LESS LIKELY AS THE NIGHT PROGRESSES.

TEMPERATURES TONIGHT WILL BE MILD...IN THE 60S.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM MONDAY/...
DEEP UPPER LEVEL RIDGE BUILDS ACROSS THE EASTERN US ON SUNDAY.
SURFACE TROUGH LINGERS ACROSS THE AREA. WITH A DRIER AIR MASS IN
PLACE...EXPECTING MORE IN THE WAY OF SUNSHINE. THIS SHOULD ALLOW
TEMPERATURES TO WARM INTO THE LOWER AND MIDDLE 80S INLAND AND IN
THE NYC METRO...AND THE UPPER 70S CLOSER TO THE COAST. INSTABILITY
WILL BE ON THE INCREASE DURING THE DAY FROM THE CITY NORTH AND
WEST. AFTERNOON SEA BREEZES FURTHER EAST WILL LIMIT INSTABILITY.
LOW CHANCE POPS FORECAST ACROSS WESTERN ZONES IN THE BETTER
INSTABILITY AND WITH SURFACE TROUGH IN THE VICINITY. HOWEVER...THE
UPPER LEVEL RIDGE SHOULD LIMIT CONVECTIVE DEVELOPMENT. IF A STORM
DEVELOPS SUNDAY...IT MAY BE SLOW MOVING WITH WEAK LOW AND MIDDLE
LEVEL FLOW.

HIGH PRESSURE WILL BEGIN TO BUILD SW ACROSS THE AREA SUNDAY NIGHT
SENDING A BACK DOOR FRONT THROUGH. MODELS DIFFER IN THE TIMING OF
THE FRONT PASSAGE. CURRENT THINKING IS THAT THE FRONT WILL BEGIN
MOVING SOUTH ACROSS THE AREA SUNDAY EVENING. WITH THIS FRONT...AN
ISOLATED SHOWER OR STORM CANNOT BE RULED OUT. AS THE LOW LEVELS
COOL AND MOISTEN BEHIND THE FRONT...SOME FOG OR DRIZZLE ARE
POSSIBLE BY DAYBREAK MONDAY. LOW TEMPERATURES IN THE UPPER 50S AND
LOWER 60S ARE FORECAST SUNDAY NIGHT.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
MODELS ARE IN GOOD AGREEMENT WITH THE H5 PATTERN THROUGH THE MIDDLE
OF NEXT WEEK. SLIGHT DIFFERENCES COME INTO PLAY WITH TIMING AND
AMPLITUDE OF A SHORTWAVE TROUGH MOVING THROUGH NEW ENGLAND ON
WED...ALTHOUGH SHOWER/TSTM ACTIVITY CURRENTLY LOOKS TO REMAIN TO OUR
N. A VORTEX DEVELOPS OVER SE CANADA AT THE END OF THE WEEK WITH
ZONAL FLOW BECOMING SW ALOFT AS A PIECE OF ENERGY MOVING AROUND THE
BASE RESULTS IN AMPLIFICATION.

AT THE SFC...A FRONTAL BOUNDARY JUST TO THE SW OF THE AREA MON
MORNING...WILL REMAIN NEARLY STATIONARY AS SUBSIDENCE FROM HIGH PRES
TO THE NE NOSES IN. LOW LEVELS SATURATE EARLY IN THE MORNING AS A
RESULT WITH STRATUS EXPECTED AND WITH WEAK LIFT IN THE SATURATED
LAYER COULD CAUSE DRIZZLE. THERE IS ALSO A WEAK SHORTWAVE MOVING
THROUGH THE FLOW ALOFT WHICH COULD CAUSE A FEW AREAS OF RAIN. THE
LATTER WILL BE DETERMINED BY HOW MUCH DRY AIR IS IN PLACE ALOFT FROM
THE HIGH. HAVE ADDED SLIGHT CHANCE RAIN OR DRIZZLE FOR A FEW HOURS MON
MORNING AS A RESULT. WITH THE FRONT NEARBY THROUGH THE DAY...HAVE
MAINTAINED THE SLIGHT CHANCE POPS MAINLY FROM NYC AND AREAS N AND W FOR ANY
ACTIVITY THAT MAY DEVELOP IN THE AFTERNOON WITH WEAK AREAS OF VORTICITY
MOVING THROUGH THE MID-LEVELS. MON NIGHT MAY END UP BEING DRY FOR
THE MOST PART WITH MODEL TRENDS INDICATING THAT ANY ACTIVITY REMAINS
TO OUR SW...BUT MAINTAINED THE SLIGHT CHANCE TO LOW CHANCE POPS FOR THE TIME
BEING SINCE THERE IS UNCERTAINTY WITH HOW MUCH THE HIGH TO THE NE
BUILDS IN.

WARM FRONT LIFTS THROUGH TUE MORNING FOLLOWED BY A COLD FRONT IN THE
EVE WITH A BETTER CHANCE FOR WIDESPREAD SHOWERS/TSTMS. HIGH PRESSURE
THEN BUILDS IN FROM THE W AND REMAINS IN CONTROL THROUGH THE END OF
THE WEEK...WITH THE EXCEPTION OF MAYBE A SHOWER ASSOCIATED WITH A
WEAK COLD FRONT DROPPING THROUGH THE AREA ON FRI AFTERNOON/EVE.

TEMPERATURES WILL GENERALLY BE ABOVE NORMAL LEVELS THROUGH THE
PERIOD.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
A SURFACE TROUGH CROSSES THE AREA EARLY THIS MORNING. A BACKDOOR
COLD FRONT APPROACHES FROM THE NORTH AND SINKS TO THE SOUTH LATER
TODAY AND MOVES THROUGH THE REGION MONDAY MORNING.

CONVECTION PRETTY MUCH DONE...AND RAIN WILL TAPER OFF BY 08-09Z.

FOG/STRATUS WILL DEVELOP THEREAFTER...MAINLY WITH MVFR CONDS...BUT
CANNOT RULE OUT IFR/LIFR CONDS.

VFR RETURNS BY 15Z.

LGT/VRB WINDS THROUGH LATE MORNING...THEN GENERALLY SW WINDS 5-10
KT...BECOMING SOUTH AT COASTAL TERMINALS DUE TO AFTERNOON SEA
BREEZES.

WINDS DIMINISH TO 5 KT OR LESS AFT 02Z MONDAY.

FOG/STRATUS LIKELY AGAIN THEREAFTER.

.OUTLOOK FOR 06Z MONDAY THROUGH THURSDAY...
.SUNDAY NIGHT-MONDAY EVENING...MVFR OR LOWER POSSIBLE IN
LOW CLOUDS/FOG. NE WINDS G15-20KT POSSIBLE DURING THE DAY ON
MONDAY.
.LATE MONDAY NIGHT-TUESDAY EVENING...MVFR OR LOWER POSSIBLE IN
FOG/STRATUS AND/OR SHRA/TSTM.
.LATE TUESDAY NIGHT-THURSDAY...VFR. NW WINDS G20+KT POSSIBLE.

&&

.MARINE...
S WINDS 10-20 KT DIMINISH OVERNIGHT. BRIEF GUSTY WINDS ARE ALSO
POSSIBLE IN ANY SHOWER AND THUNDERSTORMS THAT MAY MOVE ACROSS THE
WATERS. FOG DEVELOPS.

OTHERWISE...SUB-SCA CONDITIONS ARE FORECAST FOR THE REMAINDER OF
THE FORECAST PERIOD WITH A RELATIVELY LIGHT FLOW PERSISTING ACROSS
THE AREA. GUSTS MAY REACH AROUND 20 KT LATE TUE NIGHT THROUGH
WED.

&&

.HYDROLOGY...
BASIN AVERAGE RAINFALL OF 1/4 INCH IS POSSIBLE THROUGH SUNDAY
MORNING WITH LOCALIZED HIGHER AMOUNTS IN A BAND OF SHOWERS AND
THUNDERSTORMS. MINOR URBAN FLOODING IS POSSIBLE IN ANY OF THE
HEAVIER SHOWERS/STORMS.

AROUND 1/4 OF AN INCH OF RAINFALL IS POSSIBLE WITH THE FRONTAL
SYSTEM ON TUE.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...24/DS
NEAR TERM...DS/PW
SHORT TERM...DS
LONG TERM...24
AVIATION...MPS
MARINE...24/DS/PW
HYDROLOGY...24/DS



AREA FORECAST DISCUSSION

NWS MOUNT HOLLY NJ

 1049 AM EDT SUN MAY 17 2015

.SYNOPSIS...
A WEAK FRONT WILL REMAIN ACROSS THE REGION TODAY AND TONIGHT. WEAK
HIGH PRESSURE WILL BE ACROSS THE AREA MONDAY. A LOW PRESSURE SYSTEM
WILL MOVE ACROSS THE UPPER GREAT LAKES AND SOUTHERN CANADA BRINGING
ITS ATTACHED FRONTS TO OUR AREA MONDAY NIGHT THROUGH TUESDAY NIGHT.
HIGH PRESSURE WILL BUILD IN FOR THE MIDDLE PART OF THE WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
FOR THE MORNING UPDATE WE HAVE DECREASED POPS FOR THE REMAINDER OF
THE MORNING HOURS ACROSS THE NORTHERNEASTERN HALF OF THE CWA WHILE
THE SOUTHWESTERN HALF STILL REMAINS IN AN AREA OF BETTER MOISTURE
TRANSPORT. THE MAIN DIFFERENCE AT THIS POINT, WHEN COMPARED TO
SATURDAY, IS THE AMOUNT OF CLOUD COVER IN PLACE. THINKING THE
CURRENT CLOUD COVER WOULD BE ENOUGH TO INHIBIT THE AMOUNT OF
INSTABILITY TO WORK WITH THIS AFTERNOON BUT ANY BREAKS WOULD ALLOW
FOR POCKETS OF BETTER HEATING AND THEREFORE HIGHER CAPE VALUES.
HI-RES GUIDANCE PAINTS NUMEROUS BULLS-EYES ACROSS OUR WESTERN
AND NORTHERN ZONES AS SHORTWAVE ENERGY UNDERCUTS THE BUILDING
MID-LEVEL RIDGING WORKING INTO THE REGION. WE FOLLOWED HRRR AND
RAP GUIDANCE TO INCREASE POPS TO LIKELY THIS AFTERNOON AND
EVENING, HIGHEST FOR OUR WESTERN ZONES.

TEMPERATURE-WISE, ANOTHER WARM AND ABOVE-AVERAGE MAY DAY IS IN
STORE, WITH NOTICEABLE HUMIDITY. WE MAINLY TOOK A MET/MAV BLEND WITH
CONTINUITY FOR MAXIMUM TEMPERATURES, AND WE ANTICIPATE HIGHS TO
MAINLY BE IN THE LOWER 80S, EXCEPT SOME 70S ALONG THE COAST AND INTO
THE POCONOS.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
INTO THIS EVENING AND TONIGHT, ANY SCATTERED TSTORM AND SHOWER
ACTIVITY SHOULD WANE WITH DIMINISHING INSTABILITY AS THE WEAK
BACKDOOR FRONT CONTINUES TO EDGE FARTHER SOUTH THROUGH OUR AREA. WE
DECREASE POPS BACK TO SLIGHT CHANCE/LOW CHANCE FOR LINGERING SHOWERS
FROM EAST TO WEST ACROSS THE FORECAST AREA AS THE NIGHT PROGRESSES.

WITH THE PASSAGE OF THE WEAK FRONTAL BOUNDARY THROUGH MOST OF THE
FORECAST AREA AND A WEAK AREA OF HIGH PRESSURE BUILDING DOWN FROM
THE NORTHEAST STATES, MORE OF A NORTHEASTERLY, ONSHORE FLOW IS
EXPECTED TO DEVELOP OVERNIGHT AND INTO THE EARLY MORNING LEADING UP
TO DAYBREAK MONDAY. THIS WILL ALLOW SOME LOW CLOUDS TO DEVELOP
ACROSS THE REGION, WITH PERHAPS SOME PATCHY/AREAS OF FOG.
TEMPERATURES WILL ONCE AGAIN REMAIN MILD THROUGH THE OVERNIGHT, WITH
LOWS MAINLY IN THE 60S ACROSS THE REGION.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
MON THRU TUE NIGHT...A CONTINUATION OF THE UNSETTLED PERIOD. WARM
AND HUMID CONDITIONS AND A COLD FRONT TO CROSS THE AREA TUE/TUE
NIGHT. CHC FOR TSTMS MON THEN LIKELY SHOWERS/TSTMS FOR MON NIGHT
INTO TUE. SPC MENTIONS A MARGINAL RISK FOR SVR TSTMS TUE. DECREASING
POPS TUE NIGHT. TEMPS ABOVE NORMAL.

WED THRU SAT...HIGH PRESSURE EXTENDS ACROSS THE AREA. A DRY PERIOD
EXPECTED. TEMPERATURES NEAR NORMAL FOR THE LATER HALF OF MAY.
HIGHS MOSTLY LOW/MID 70S WITH LOWS IN THE 40S NORTH AND 50S SOUTH.

&&

.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

REST OF TODAY...VFR CEILINGS ARE ANTICIPATED TO CONTINUE THROUGH
THE DAY, WITH SOME SCATTERED SHWRS/TSTORMS POSSIBLE. THE BEST
TIMING FOR THIS ACTIVITY LOOKS TO BE IN THE AFTERNOON AND EVENING,
AND THIS HAS BEEN INCLUDED IN THE TAFS. THUNDER WAS NOT INCLUDED,
THOUGH, AS CONFIDENCE IN THE TIMING AND COVERAGE OF TSTORMS IS TOO
UNCERTAIN AT THIS TIME. WESTERLY WINDS INCREASING UP TO AROUND 10
KNOTS ARE EXPECTED THROUGH THE DAYTIME.

TONIGHT...ANY SCATTERED SHWRS/TSTORMS ARE EXPECTED TO DIMINISH TO
MORE ISOLATED ACTIVITY INTO TONIGHT, WITH WESTERLY WINDS FALLING OFF
TO AROUND 5 KNOTS. DURING THE EARLY MORNING HOURS LEADING UP TO
DAYBREAK MONDAY, AN ONSHORE FLOW WILL BEGIN TO DEVELOP ACROSS THE
REGION, WITH NORTHEASTERLY WINDS IN THE 5 TO 8 KNOT RANGE. THE
CONTINUED LOW LEVEL MOISTURE IN PLACE WILL ALLOW CIGS/VSBYS TO FALL
TO MVFR OR LOCALIZED IFR CONDITIONS.

OUTLOOK...
MON THRU TUE NIGHT...MOSTLY VFR EXCEPT IN SCT SHOWERS/TSTMS.
WED THRU THU...MOSTLY VFR.

&&

.MARINE...
SUB-ADVISORY CONDITIONS ARE ANTICIPATED TO CONTINUE FOR THE COASTAL
WATERS AND DELAWARE BAY THROUGH TODAY AND TONIGHT. SOME WIND GUSTS
BETWEEN 15 TO 20 KNOTS ARE POSSIBLE THROUGH THE DAYTIME OVER THE
WATERS, WITH SEAS AVERAGING 3 TO 4 FEET FOR THE COASTAL WATERS AND
AROUND 2 FEET FOR DELAWARE BAY.

OUTLOOK...
MON THRU TUE NIGHT...SUB-SCA CONDITIONS WITH SCT TSTMS.
WED THRU THU...SUB-SCA CONDITIONS. FAIR WEATHER.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...O`HARA
NEAR TERM...HEAVENER/KLINE
SHORT TERM...KLINE
LONG TERM...O`HARA
AVIATION...KLINE/O`HARA
MARINE...KLINE/O`HARA



AREA FORECAST DISCUSSION

NWS MOUNT HOLLY NJ

 623 AM EDT SUN MAY 17 2015

.SYNOPSIS...
A WEAK FRONT WILL REMAIN ACROSS THE REGION TODAY AND TONIGHT. WEAK
HIGH PRESSURE WILL BE ACROSS THE AREA MONDAY. A LOW PRESSURE SYSTEM
WILL MOVE ACROSS THE UPPER GREAT LAKES AND SOUTHERN CANADA BRINGING
ITS ATTACHED FRONTS TO OUR AREA MONDAY NIGHT THROUGH TUESDAY NIGHT.
HIGH PRESSURE WILL BUILD IN FOR THE MIDDLE PART OF THE WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MAINLY CLOUDY CONDITIONS, ISOLATED SHOWERS, AND EVEN SOME PATCHY FOG
ARE EXPECTED AT THE START OF THE DAY, WITH AMPLE LOW LEVEL MOISTURE
REMAINING ACROSS THE REGION. WHILE ANY PATCHY FOG SHOULD DISSIPATE
EARLY ON, THE CLOUDS ARE EXPECTED TO REMAIN THROUGH THE DAY, WITH
ONLY A FEW BREAKS POSSIBLE. AN UPPER LEVEL RIDGE WILL BE IN PLACE
OVER THE REGION THROUGH THE DAY, WITH A WEAK FRONTAL BOUNDARY DRAPED
TO OUR NORTH INTO NEW YORK STATE. THE AMPLE MOISTURE IN PLACE AND
THIS WEAK BOUNDARY PERHAPS EDGING SOUTHWARD THROUGH THE DAY WILL
YIELD SOME ISOLATED TO SCATTERED SHOWERS ACROSS OUR REGION, AND
PERHAPS SOME THUNDER INTO THE AFTERNOON AND EVENING, DEPENDING ON
DEVELOPING INSTABILITY THROUGH THE DAYTIME. WE FOLLOWED HRRR AND RAP
GUIDANCE TO INCREASE POPS TO LIKELY THIS AFTERNOON AND EVENING,
HIGHEST FOR OUR WESTERN ZONES.

TEMPERATURE-WISE, ANOTHER WARM AND ABOVE-AVERAGE MAY DAY IS IN
STORE, WITH NOTICEABLE HUMIDITY. WE MAINLY TOOK A MET/MAV BLEND WITH
CONTINUITY FOR MAXIMUM TEMPERATURES, AND WE ANTICIPATE HIGHS TO
MAINLY BE IN THE LOWER 80S, EXCEPT SOME 70S ALONG THE COAST AND INTO
THE POCONOS.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
INTO THIS EVENING AND TONIGHT, ANY SCATTERED TSTORM AND SHOWER
ACTIVITY SHOULD WANE WITH DIMINISHING INSTABILITY AS THE WEAK
BACKDOOR FRONT CONTINUES TO EDGE FARTHER SOUTH THROUGH OUR AREA. WE
DECREASE POPS BACK TO SLIGHT CHANCE/LOW CHANCE FOR LINGERING SHOWERS
FROM EAST TO WEST ACROSS THE FORECAST AREA AS THE NIGHT PROGRESSES.

WITH THE PASSAGE OF THE WEAK FRONTAL BOUNDARY THROUGH MOST OF THE
FORECAST AREA AND A WEAK AREA OF HIGH PRESSURE BUILDING DOWN FROM
THE NORTHEAST STATES, MORE OF A NORTHEASTERLY, ONSHORE FLOW IS
EXPECTED TO DEVELOP OVERNIGHT AND INTO THE EARLY MORNING LEADING UP
TO DAYBREAK MONDAY. THIS WILL ALLOW SOME LOW CLOUDS TO DEVELOP
ACROSS THE REGION, WITH PERHAPS SOME PATCHY/AREAS OF FOG.
TEMPERATURES WILL ONCE AGAIN REMAIN MILD THROUGH THE OVERNIGHT, WITH
LOWS MAINLY IN THE 60S ACROSS THE REGION.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
MON THRU TUE NIGHT...A CONTINUATION OF THE UNSETTLED PERIOD. WARM
AND HUMID CONDITIONS AND A COLD FRONT TO CROSS THE AREA TUE/TUE
NIGHT. CHC FOR TSTMS MON THEN LIKELY SHOWERS/TSTMS FOR MON NIGHT
INTO TUE. SPC MENTIONS A MARGINAL RISK FOR SVR TSTMS TUE. DECREASING
POPS TUE NIGHT. TEMPS ABOVE NORMAL.

WED THRU SAT...HIGH PRESSURE EXTENDS ACROSS THE AREA. A DRY PERIOD
EXPECTED. TEMPERATURES NEAR NORMAL FOR THE LATER HALF OF MAY.
HIGHS MOSTLY LOW/MID 70S WITH LOWS IN THE 40S NORTH AND 50S SOUTH.

&&

.AVIATION /10Z SUNDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

EARLY MORNING...MOST OF THE TAF SITES WILL START THE DAY WITH VFR
CONDITIONS. SOME MVFR VSBYS REMAIN FOR THE MORE RURAL, SHELTERED
AREAS WHERE AMPLE LOW-LEVEL MOISTURE ALLOWED SOME GENERALLY LIGHT
FOG TO DEVELOP, NAMELY AT KRDG/KABE/KTTN. WINDS OVERALL THIS
MORNING WILL START OUT LIGHT AND VARIABLE OR AT A WEST-SOUTHWEST
DIRECTION AT 5 KNOTS OR LESS.

REST OF TODAY...ANY REMAINING MVFR VSBYS ARE EXPECTED TO IMPROVE
TO VFR CONDITIONS BY ABOUT 13Z ACROSS THE REGION. VFR CEILINGS ARE
ANTICIPATED TO CONTINUE THROUGH THE DAY, WITH SOME SCATTERED
SHWRS/TSTORMS POSSIBLE. THE BEST TIMING FOR THIS ACTIVITY LOOKS TO
BE IN THE AFTERNOON AND EVENING, AND THIS HAS BEEN INCLUDED IN THE
TAFS. THUNDER WAS NOT INCLUDED, THOUGH, AS CONFIDENCE IN THE
TIMING AND COVERAGE OF TSTORMS IS TOO UNCERTAIN AT THIS TIME.
WESTERLY WINDS INCREASING UP TO AROUND 10 KNOTS ARE EXPECTED
THROUGH THE DAYTIME.

TONIGHT...ANY SCATTERED SHWRS/TSTORMS ARE EXPECTED TO DIMINISH TO
MORE ISOLATED ACTIVITY INTO TONIGHT, WITH WESTERLY WINDS FALLING OFF
TO AROUND 5 KNOTS. DURING THE EARLY MORNING HOURS LEADING UP TO
DAYBREAK MONDAY, AN ONSHORE FLOW WILL BEGIN TO DEVELOP ACROSS THE
REGION, WITH NORTHEASTERLY WINDS IN THE 5 TO 8 KNOT RANGE. THE
CONTINUED LOW LEVEL MOISTURE IN PLACE WILL ALLOW CIGS/VSBYS TO FALL
TO MVFR OR LOCALIZED IFR CONDITIONS.

OUTLOOK...
MON THRU TUE NIGHT...MOSTLY VFR EXCEPT IN SCT SHOWERS/TSTMS.
WED THRU THU...MOSTLY VFR.

&&

.MARINE...
SUB-ADVISORY CONDITIONS ARE ANTICIPATED TO CONTINUE FOR THE COASTAL
WATERS AND DELAWARE BAY THROUGH TODAY AND TONIGHT. SOME WIND GUSTS
BETWEEN 15 TO 20 KNOTS ARE POSSIBLE THROUGH THE DAYTIME OVER THE
WATERS, WITH SEAS AVERAGING 3 TO 4 FEET FOR THE COASTAL WATERS AND
AROUND 2 FEET FOR DELAWARE BAY.

OUTLOOK...
MON THRU TUE NIGHT...SUB-SCA CONDITIONS WITH SCT TSTMS.
WED THRU THU...SUB-SCA CONDITIONS. FAIR WEATHER.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...O`HARA
NEAR TERM...KLINE
SHORT TERM...KLINE
LONG TERM...O`HARA
AVIATION...KLINE/O`HARA
MARINE...KLINE/O`HARA




AREA FORECAST DISCUSSION

NWS MOUNT HOLLY NJ

 428 AM EDT SUN MAY 17 2015

.SYNOPSIS...
A WEAK FRONT WILL REMAIN ACROSS THE REGION TODAY AND TONIGHT. WEAK
HIGH PRESSURE WILL BE ACROSS THE AREA MONDAY. A LOW PRESSURE SYSTEM
WILL MOVE ACROSS THE UPPER GREAT LAKES AND SOUTHERN CANADA BRINGING
ITS ATTACHED FRONTS TO OUR AREA MONDAY NIGHT THROUGH TUESDAY NIGHT.
HIGH PRESSURE WILL BUILD IN FOR THE MIDDLE PART OF THE WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
MAINLY CLOUDY CONDITIONS, ISOLATED SHOWERS, AND EVEN SOME PATCHY FOG
ARE EXPECTED AT THE START OF THE DAY, WITH AMPLE LOW LEVEL MOISTURE
REMAINING ACROSS THE REGION. WHILE ANY PATCHY FOG SHOULD DISSIPATE
EARLY ON, THE CLOUDS ARE EXPECTED TO REMAIN THROUGH THE DAY, WITH
ONLY A FEW BREAKS POSSIBLE. AN UPPER LEVEL RIDGE WILL BE IN PLACE
OVER THE REGION THROUGH THE DAY, WITH A WEAK FRONTAL BOUNDARY DRAPED
TO OUR NORTH INTO NEW YORK STATE. THE AMPLE MOISTURE IN PLACE AND
THIS WEAK BOUNDARY PERHAPS EDGING SOUTHWARD THROUGH THE DAY WILL
YIELD SOME ISOLATED TO SCATTERED SHOWERS ACROSS OUR REGION, AND
PERHAPS SOME THUNDER INTO THE AFTERNOON AND EVENING, DEPENDING ON
DEVELOPING INSTABILITY THROUGH THE DAYTIME. WE FOLLOWED HRRR AND RAP
GUIDANCE TO INCREASE POPS TO LIKELY THIS AFTERNOON AND EVENING,
HIGHEST FOR OUR WESTERN ZONES.

TEMPERATURE-WISE, ANOTHER WARM AND ABOVE-AVERAGE MAY DAY IS IN
STORE, WITH NOTICEABLE HUMIDITY. WE MAINLY TOOK A MET/MAV BLEND WITH
CONTINUITY FOR MAXIMUM TEMPERATURES, AND WE ANTICIPATE HIGHS TO
MAINLY BE IN THE LOWER 80S, EXCEPT SOME 70S ALONG THE COAST AND INTO
THE POCONOS.

&&

.SHORT TERM / MONDAY THROUGH 6 AM MONDAY/...
INTO THIS EVENING AND TONIGHT, ANY SCATTERED TSTORM AND SHOWER
ACTIVITY SHOULD WANE WITH DIMINISHING INSTABILITY AS THE WEAK
BACKDOOR FRONT CONTINUES TO EDGE FARTHER SOUTH THROUGH OUR AREA. WE
DECREASE POPS BACK TO SLIGHT CHANCE/LOW CHANCE FOR LINGERING SHOWERS
FROM EAST TO WEST ACROSS THE FORECAST AREA AS THE NIGHT PROGRESSES.

WITH THE PASSAGE OF THE WEAK FRONTAL BOUNDARY THROUGH MOST OF THE
FORECAST AREA AND A WEAK AREA OF HIGH PRESSURE BUILDING DOWN FROM
THE NORTHEAST STATES, MORE OF A NORTHEASTERLY, ONSHORE FLOW IS
EXPECTED TO DEVELOP OVERNIGHT AND INTO THE EARLY MORNING LEADING UP
TO DAYBREAK MONDAY. THIS WILL ALLOW SOME LOW CLOUDS TO DEVELOP
ACROSS THE REGION, WITH PERHAPS SOME PATCHY/AREAS OF FOG.
TEMPERATURES WILL ONCE AGAIN REMAIN MILD THROUGH THE OVERNIGHT, WITH
LOWS MAINLY IN THE 60S ACROSS THE REGION.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
MON THRU TUE NIGHT...A CONTINUATION OF THE UNSETTLED PERIOD. WARM
AND HUMID CONDITIONS AND A COLD FRONT TO CROSS THE AREA TUE/TUE
NIGHT. CHC FOR TSTMS MON THEN LIKELY SHOWERS/TSTMS FOR MON NIGHT
INTO TUE. SPC MENTIONS A MARGINAL RISK FOR SVR TSTMS TUE. DECREASING
POPS TUE NIGHT. TEMPS ABOVE NORMAL.

WED THRU SAT...HIGH PRESSURE EXTENDS ACROSS THE AREA. A DRY PERIOD
EXPECTED. TEMPERATURES NEAR NORMAL FOR THE LATER HALF OF MAY.
HIGHS MOSTLY LOW/MID 70S WITH LOWS IN THE 40S NORTH AND 50S SOUTH.

&&

.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

THROUGH EARLY MORNING...SOME SUB-VFR VSBYS AND/OR CIGS ARE EXPECTED
TO DEVELOP ACROSS THE REGION, WITH AMPLE LOW LEVEL MOISTURE IN
PLACE. MOST OF THE TAF SITES ARE EXPECTED TO HAVE VSBYS DECREASE TO
MVFR, MOSTLY IN THE 4 TO 5 SM RANGE, WITH CONTINUED VFR CEILINGS.
FOR OUR WESTERN AND MORE NORTHERN TAF SITES, NAMELY KRDG/KABE/KTTN,
GUIDANCE INDICATES THAT BOTH VSBYS AND CIGS ARE EXPECTED TO DECREASE
TO MVFR CONDITIONS FOR A TIME. WINDS OVERALL WILL AVERAGE OUT OF THE
WEST-SOUTHWEST AT 5 KNOTS OR LESS, WITH SOME SITES GOING LIGHT AND
VARIABLE.

REST OF TODAY...ANY MVFR VSBYS AND/OR CIGS ARE EXPECTED TO IMPROVE
TO VFR CONDITIONS BY ABOUT 13Z ACROSS THE REGION. VFR CEILINGS ARE
ANTICIPATED TO CONTINUE THROUGH THE DAY, WITH SOME SCATTERED
SHWRS/TSTORMS POSSIBLE. THE BEST TIMING FOR THIS ACTIVITY LOOKS TO
BE IN THE AFTERNOON AND EVENING, AND THIS HAS BEEN INCLUDED IN THE
TAFS. THUNDER WAS NOT INCLUDED, THOUGH, AS CONFIDENCE IN THE TIMING
AND COVERAGE OF TSTORMS IS TOO UNCERTAIN AT THIS TIME. WESTERLY
WINDS INCREASING UP TO AROUND 10 KNOTS ARE EXPECTED THROUGH THE
DAYTIME.

TONIGHT...ANY SCATTERED SHWRS/TSTORMS ARE EXPECTED TO DIMINISH TO
MORE ISOLATED ACTIVITY INTO TONIGHT, WITH WESTERLY WINDS FALLING OFF
TO AROUND 5 KNOTS. DURING THE EARLY MORNING HOURS LEADING UP TO
DAYBREAK MONDAY, AN ONSHORE FLOW WILL BEGIN TO DEVELOP ACROSS THE
REGION, WITH NORTHEASTERLY WINDS IN THE 5 TO 8 KNOT RANGE. THE
CONTINUED LOW LEVEL MOISTURE IN PLACE WILL ALLOW CIGS/VSBYS TO FALL
TO MVFR OR LOCALIZED IFR CONDITIONS.

OUTLOOK...
MON THRU TUE NIGHT...MOSTLY VFR EXCEPT IN SCT SHOWERS/TSTMS.
WED THRU THU...MOSTLY VFR.

&&

.MARINE...
SUB-ADVISORY CONDITIONS ARE ANTICIPATED TO CONTINUE FOR THE COASTAL
WATERS AND DELAWARE BAY THROUGH TODAY AND TONIGHT. SOME WIND GUSTS
BETWEEN 15 TO 20 KNOTS ARE POSSIBLE THROUGH THE DAYTIME OVER THE
WATERS, WITH SEAS AVERAGING 3 TO 4 FEET FOR THE COASTAL WATERS AND
AROUND 2 FEET FOR DELAWARE BAY.

OUTLOOK...
MON THRU TUE NIGHT...SUB-SCA CONDITIONS WITH SCT TSTMS.
WED THRU THU...SUB-SCA CONDITIONS. FAIR WEATHER.

&&


.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...O`HARA
NEAR TERM...KLINE
SHORT TERM...KLINE
LONG TERM...O`HARA
AVIATION...KLINE/O`HARA
MARINE...KLINE/O`HARA



AREA FORECAST DISCUSSION

NWS TAMPA BAY RUSKIN FL

 352 PM EDT SUN MAY 17 2015

.SYNOPSIS...
SYNOPSIS...
19Z WATER VAPOR AND H4 RAP ANALYSIS CONTINUE TO SHOW AN AMPLIFIED
UPPER LEVEL PATTERN IN PLACE ACROSS THE CONUS. A LONGWAVE TROUGH
WITH A NOW HIGHLY NEGATIVE TILT IS PIVOTING NORTHWARD THROUGH THE
CENTRAL/NORTHERN PLAINS AND UPPER MIDWEST...WHILE DOWNSTREAM WE
FIND AMPLIFIED RIDGING OVER THE EASTERN THIRD OF THE NATION...
INCLUDING THE FL PENINSULA. THE 12Z KTBW SOUNDING SHOWS A FAIRLY
MOIST COLUMN WITH A PW VALUE OF OVER 1.5"...AND LITTLE OVERALL
RESISTANCE TO PARCEL LIFT. LOW AND MID LEVEL LAPSE RATES ARE RIGHT
AROUND 6C/KM. ONCE AGAIN...WE DO NOT SEE ANY SIGNIFICANT LAYERS OF
HOSTILE AIR TOWARD DEEP CONVECTION WITH MINIMUM THETAE VALUES
WITHIN THE 700-500MB LAYER ALL GENERALLY ABOVE 322K. THE SOUNDING
SHOWS WHAT WOULD BE EXPECTED UNDER THE MIDDLE OF A BIG UPPER
RIDGE...AND THAT IS WEAK...ALMOST VARIABLE FLOW THROUGH THE TROP
COLUMN. THIS WEAK FLOW IS GOING TO RESULT IN SLOW STORM MOTION
TODAY AS WELL. IF THE DEGREE OF THUNDERSTORM DEVELOPMENT EXPECTED
COMES TO PASS...THEN THE THREAT OF LOCALIZED FLOODING EXISTS
TODAY...ESPECIALLY IF ANY OF THE STORMS MIGRATE OVER URBAN
CENTERS.

AT THE SURFACE...ATLANTIC HIGH PRESSURE HAS SETTLED A BIT SOUTH
DURING THE PAST 24 HOURS...AND NOW RIDGES BACK WESTWARD TO NEAR
OR JUST NORTH OF THE I-10 CORRIDOR. THE RESULTING SYNOPTIC FLOW
PATTERN (1000-700MB) ACROSS OUR REGION IS 5-10 KNOTS FROM THE
E/SE.

&&

.SHORT TERM...
UPDATE (REST OF TODAY AND TONIGHT)... AS MENTIONED IN THE
SYNOPSIS OUR LARGE SCALE FLOW PATTERN IS 5-10 KNOTS FROM THE EAST
TO SOUTHEAST TODAY. THIS MODERATE SOUTHEAST FLOW IS GENERALLY OUR
MOST ACTIVE SUMMER THUNDERSTORM REGIME...AS IT BOTH TENDS TO BE
ASSOCIATED WITH A MOIST PATTERN...AND ALSO PROVIDES THE
MECHANISMS FOR ENHANCED LOW LEVEL FOCUS/CONVERGENCE ALONG THE WEST
COAST SEABREEZE. YESTERDAY...WHERE THE SEA-BREEZE WAS ABLE TO MAKE
A BIT OF SMALL PROGRESS INLAND (BASICALLY SOUTH OF TAMPA
BAY)...THIS CONVERGENCE WAS EFFICIENT AND THUNDERSTORMS ERUPTED
VERY CLOSE TO THE COAST LATE IN THE AFTERNOON. TODAY...THE FLOW
JUST ABOVE THE SURFACE APPEARS LIGHT ENOUGH TO ALLOW THIS MORE
EFFICIENT CONVERGENCE TO OCCUR ALONG MUCH...IF NOT ALL OF THE
FLORIDA WEST COAST. THEREFORE...THINK WE WILL SEE THE ACTIVE
CONVECTION EXPAND NORTHWARD THROUGH THE LATER AFTERNOON/EARLY
EVENING HOURS INTO THE TAMPA BAY AREA...AND EVEN NORTHWARD
THROUGH QUITE A BIT OF THE NATURE COAST. THE HRRR GUIDANCE THUS
FAR TODAY HAS BEEN VERY AGGRESSIVE WITH THE CONVECTION ALONG OUR
ENTIRE I-75 CORRIDOR...AND GIVEN THE FAVORABLE SYNOPTIC SETUP...SEE
LITTLE REASON TO DISAGREE WITH ITS GENERAL OUTPUT. RAIN CHANCES IN
THE 60-70% RANGE SEEM REASONABLE ALONG THE GENERAL I-75 CORRIDOR
NORTHWARD TO NEAR BROOKSVILLE... AND THEN WILL HAVE 50% FOR THE
FAR NORTHERN ZONES. BTW...THE HRRR DID A VERY GOOD JOB WITH THE
PLACEMENT AND TIMING OF THE CONVECTION ON SATURDAY...SHOWING
CONVECTIVE COVERAGE MAINLY EXTENDING FROM MANATEE COUNTY SOUTHWARD
ALONG THE COAST DURING THE MORNING RUNS. THIS VERIFIED VERY WELL.

THERE IS NOT A WHOLE LOT OF MOTION IN THE ATMOSPHERE SITTING UNDER
THE MIDDLE OF THE UPPER RIDGE...AND THEREFORE STORMS ARE NOT GOING
TO BE FAST MOVERS...PROPELLED ALONG BY WEAK FLOW...AND/OR OUTFLOW
BOUNDARY MOVEMENT. THE GENERAL MOTION SHOULD BE TOWARD THE COAST
AND EVENTUALLY OFFSHORE. HOWEVER...THE SLOW MOTION IS GOING TO
RESULT IN A HEAVY RAIN/LOCALIZED FLOODING THREAT. ALL OF THE
CONVECTION ALLOWING GUIDANCE IS SHOWING THE POTENTIAL FOR
IMPRESSIVE UPDRAFT VELOCITY VALUES AS WELL (MAXIMUM VALUES ON THE
ORDER OF 14-18M/S). THE STRONG UPDRAFTS WOULD BE CORRELATED WITH
VERY EFFICIENT LIGHTING PRODUCTION AS WELL.

ACTIVITY LINGERS INTO THE EVENING HOURS...AND MAY EVEN PEAK IN
SOME SPOTS BETWEEN 6-9PM. THEREAFTER...MOST GUIDANCE MEMBERS SHOW
THE STORMS MIGRATING OFFSHORE INTO THE EASTERN GULF AND WEAKENING.
WILL SLOWLY RAMP DOWN POPS NEAR THE COAST THROUGH THE MID/LATE
EVENING...AND RETURN ALL AREAS TO A DRY FORECAST AFTER MIDNIGHT.
THE LOW LEVEL MOISTURE WILL KEEP US SEASONABLY WARM OVERNIGHT...
WITH MOST SPOTS SEEING LOW TEMPS BY SUNRISE IN THE UPPER 60S TO
LOWER 70S.

ON MONDAY...WE ARE STILL UNDER THE UPPER RIDGE...HOWEVER THE RIDGE
AXIS BEGIN TO SHIFT WESTWARD OVER THE GULF OF MEXICO BY THE END OF
THE DAY. THE BIGGER CHANGE TO INFLUENCE OUR FORECAST WILL BE THE
CONTINUED SLOW MOVEMENT AND GENERAL WEAKENING OF THE SUBTROPICAL
ATLANTIC RIDGE. OUR FLOW LOOKS TO BECOME MUCH LIGHTER AND MORE
VARIABLE IN NATURE BY MONDAY AFTERNOON...AND THIS WILL FOR THE
FIRST TIME IN SEVERAL DAYS NOT ENHANCE FOCUS ALONG THE WEST COAST
SEA BREEZE. WE STILL EXPECT A FEW STORMS TO BUILD DURING THE
AFTERNOON HOURS...HOWEVER THE POTENTIAL COVERAGE IS MUCH LESS
THAN TODAY...AND WILL KEEP ALL AREAS AT 30-40% OR LESS FOR RAIN
CHANCES. AFTERNOON TEMPERATURES SHOULD GENERALLY RISE INTO THE
UPPER 80S TO NEAR 90...WITH LOWER TO MIDDLE 80S AT THE BEACHES
WITH THE DEVELOPING ONSHORE FLOW.

&&

.LONG TERM (TUESDAY THROUGH NEXT SUNDAY)...ALOFT - UPPER LEVEL
RIDGING INITIALLY ACROSS MUCH OF THE GULF REGION PUSHES BACK TO THE
WESTERN GULF BY MID-WEEK AS A TROUGH SWEEPS OVER THE GREAT LAKES AND
INTO THE LOWER SAINT LAWRENCE VALLEY..SAGGING DOWN THE EASTERN
SEABOARD. FOR THE LATTER HALF OF THE WEEK A PACIFIC LOW MOVES ACROSS
CA TO THE GREAT BASIN THEN OUT OVER THE CENTRAL PLAINS...AS A
TROUGH...FOR THE WEEKEND. IN RESPONSE THE WEST GULF RIDGE BUILDS
BACK INTO THE REST OF THE GULF AND OVER THE SOUTHEASTERN STATES.
SURFACE - HIGH PRESSURE SPRAWLS FROM THE NORTHERN PLAINS SOUTH TO A
FRONT THAT ARCS FROM THE GREAT LAKES THROUGH THE SOUTHERN PLAINS
THEN UP ACROSS THE INTERIOR PACIFIC NORTHWEST. ATLANTIC HIGH
PRESSURE RIDGES WEST THROUGH NORTH FL TO THE CENTRAL GULF COAST.
WITH TIME THE PLAINS HIGH PRESSURE SETTLES INTO THE MID CONUS THEN
TRACKS EAST...REACHING THE LOWER GREAT LAKES AND NORTHEAST U.S. BY
SUN. THIS WILL ADVANCE THE FRONT EAST AND SOUTH...BECOMING DIFFUSE
ACROSS THE CENTRAL GULF COAST AND NORTHERN FL. AS A RESULT THE
ATLANTIC RIDGE SAGS SOUTH OF THE STATE BY MID-WEEK THEN LIFTS BACK
NORTH FOR THE WEEKEND AND GETS REINFORCED BY THE HIGH OVER THE
NORTHEAST BRIDGING THE FRONT.

AMPLE MOISTURE...MODEL PWAT VALUES RUN 1.5 TO 1.8 INCHES...WILL
REMAIN IN PLACE FOR MOST OF THE PERIOD TO SUPPORT ISOLATED TO
SCATTERED SHOWERS AND THUNDERSTORMS. THE EXCEPTION WILL BE AROUND
FRI WHEN SLIGHTLY DRIER AIR FILTERS IN WITH SHOWER AND STORMS
COVERAGE DECREASING SOME. AS THE SURFACE RIDGE AXIS TRAVERSES SOUTH
DURING THE EARLY PART OF THE PERIOD LOW LEVEL SOUTHEAST FLOW/ WITH
AFTERNOON SEA BREEZES/ SWITCHES TO WESTERLY THROUGH THU...WITH
SHOWERS AND STORMS FAVORING INLAND LOCATIONS. THEN WINDS VEER
THROUGH THE NORTH LATE THU AND FRI AS HIGH PRESSURE MOVES INTO THE
EASTERN CONUS AND PUSHES THE FRONT DOWN ACROSS THE STATE...WHICH
ALONG WITH THE BUILDING UPPER RIDGE EXPLAINS THE SLIGHTLY DRIER AIR
FRI. EAST AND SOUTHEAST LOW LEVEL FLOW...WITH AFTERNOON SEA
BREEZES...RETURNS FOR THE WEEKEND. TEMPERATURES WILL RUN NEAR OR
JUST ABOVE NORMAL.

&&

.AVIATION...
VFR CONDITIONS LATE THIS MORNING ACROSS WEST-CENTRAL FLORIDA.
SCT-BKN CUMULUS FIELD HAS ALREADY DEVELOPED AND WILL BE WITH US
THE REST OF THE DAY...WITH BASES RAISING FROM AROUND 3KFT TO 5KFT
THROUGH THE AFTERNOON. THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG
THE I-75 CORRIDOR THIS AFTERNOON AND PROGRESS WESTWARD TOWARD THE
COAST AFTER DEVELOPMENT. HAVE INCLUDED TEMPOS FOR THE EXPECTED
CONVECTION. ACTIVITY WILL PROGRESS OFFSHORE BY LATE EVENING.

&&

.MARINE...
ONSHORE WINDS ALONG THE COAST WILL SHIFT BACK TO AN EASTERLY
OFFSHORE DIRECTION BY LATER THIS EVENING. SHOWERS AND
THUNDERSTORMS THAT DEVELOP OVER THE LAND LATE TODAY WILL SHIFT
WESTWARD TOWARD THE COASTAL WATERS THROUGH THIS EVENING. BOATERS
ON THE COASTAL WATERS AND BAYS SHOULD KEEP A CLOSE WATCH ON THE
WEATHER AND BE PREPARED TO SEEK SAFE HARBOR QUICKLY...AS STORMS
ARE LIKELY TO RAPIDLY DEVELOP AND MOVE OFFSHORE. BY TUESDAY AND
THROUGH THE REST OF THE WEEK...WIND FLOW WILL BECOME MORE
WESTERLY...AND KEEP THE MAJORITY OF THE STORMS INLAND. WINDS AND
SEAS ARE EXPECTED TO REMAIN BELOW HEADLINE CRITERIA.

&&

.FIRE WEATHER...
NO FIRE WEATHER CONCERNS FOR THE NEXT FEW DAYS AS RELATIVE
HUMIDITY VALUES WILL REMAIN ABOVE CRITICAL LEVELS. AFTER A ROUND
OF NUMEROUS THUNDERSTORMS ALONG THE I-75 CORRIDOR INTO THIS
EVENING...THE PATTERN WILL BEGIN TO CHANGE. STORMS APPEAR LESS
NUMEROUS FOR MONDAY...AND THEN WILL BE MAINLY LOCATED INLAND FROM
THE I-75 CORRIDOR DURING THE MIDDLE PORTION OF THE WEEK.

FOG IMPACT...NO SIGNIFICANT FOG IS EXPECTED FOR THE NEXT FEW
DAYS...BUT LATE NIGHT PATCHY GROUND FOG COULD DEVELOP IN AREAS
THAT SEE RAIN DURING THE EVENING HOURS.

&&

.PRELIMINARY POINT TEMPS/POPS...
TPA  73  87  75  88 /  50  30  30  40
FMY  71  89  73  90 /  40  30  20  20
GIF  71  89  72  92 /  10  30  20  40
SRQ  72  86  73  87 /  50  20  30  20
BKV  70  89  69  90 /  40  40  20  40
SPG  75  87  75  88 /  50  30  30  30

&&

.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.

&&

$$

SYNOPSIS/SHORT TERM/AVIATION/MARINE/FIRE WEATHER...14/MROCZKA
LONG TERM/DECISION SUPPORT...09/RUDE



AREA FORECAST DISCUSSION

NWS TAMPA BAY RUSKIN FL

 1201 PM EDT SUN MAY 17 2015

.SYNOPSIS...
16Z WATER VAPOR AND H4 RAP ANALYSIS CONTINUE TO SHOW AN AMPLIFIED
UPPER LEVEL PATTERN IN PLACE ACROSS THE CONUS. A LONGWAVE TROUGH
WITH A NOW HIGHLY NEGATIVE TILT IS PIVOTING NORTHWARD THROUGH THE
CENTRAL/NORTHERN PLAINS AND UPPER MIDWEST...WHILE DOWNSTREAM WE
FIND AMPLIFIED RIDGING OVER THE EASTERN THIRD OF THE NATION...
INCLUDING THE FL PENINSULA. THE 12Z KTBW SOUNDING SHOWS A FAIRLY
MOIST COLUMN WITH A PW VALUE OF OVER 1.5"...AND LITTLE OVERALL
RESISTANCE TO PARCEL LIFT. LOW AND MID LEVEL LAPSE RATES ARE RIGHT
AROUND 6C/KM. ONCE AGAIN...WE DO NOT SEE ANY SIGNIFICANT LAYERS
OF HOSTILE AIR TOWARD DEEP CONVECTION WITH MINIMUM THETAE VALUES
WITHIN THE 700-500MB LAYER ALL GENERALLY ABOVE 322K. THE SOUNDING
SHOWS WHAT WOULD BE EXPECTED UNDER THE MIDDLE OF A BIG UPPER
RIDGE...AND THAT IS WEAK...ALMOST VARIABLE FLOW THROUGH THE TROP
COLUMN. THIS WEAK FLOW IS GOING TO RESULT IN SLOW STORM MOTION
TODAY AS WELL. IF THE DEGREE OF THUNDERSTORM DEVELOPMENT EXPECTED
COMES TO PASS...THEN THE THREAT OF LOCALIZED FLOODING EXISTS
TODAY...ESPECIALLY IF ANY OF THE STORMS MIGRATE OVER URBAN
CENTERS.

AT THE SURFACE...ATLANTIC HIGH PRESSURE HAS SETTLED A BIT SOUTH
DURING THE PAST 24 HOURS...AND NOW RIDGES BACK WESTWARD TO NEAR
OR JUST NORTH OF THE I-10 CORRIDOR. THE RESULTING SYNOPTIC FLOW
PATTERN (1000-700MB) ACROSS OUR REGION IS 5-10 KNOTS FROM THE
E/SE. SOUNDING SHOWED PLENTY OF LOW LEVEL MOISTURE IN PLACE...AND
DIURNAL MIXING HAS ALREADY RESULTED IN A SCT-BKN CUMULUS FIELDS
ACROSS BASICALLY THE ENTIRE FL PENINSULA THIS MIDDAY. REGIONAL
RADARS ARE EVEN SHOWING A FEW SCT SHOWERS INLAND FROM THE I-75
CORRIDOR. THESE ARE JUST THE PRECURSOR TO THE MORE VIGEROUS
CONVECTION EXPECTED ALONG AND INSIDE THE I-75 CORRIDOR LATER
TODAY.

&&

.UPDATE (REST OF TODAY AND TONIGHT)... AS MENTIONED IN THE
SYNOPSIS OUR LARGE SCALE FLOW PATTERN IS 5-10 KNOTS FROM THE EAST
TO SOUTHEAST TODAY. THIS MODERATE SOUTHEAST FLOW IS GENERALLY OUR
MOST ACTIVE SUMMER THUNDERSTORM REGIME...AS IT BOTH TENDS TO BE
ASSOCIATED WITH A MOIST PATTERN...AND ALSO PROVIDES THE
MECHANISMS FOR ENHANCED LOW LEVEL FOCUS/CONVERGENCE ALONG THE WEST
COAST SEABREEZE. YESTERDAY...WHERE THE SEA-BREEZE WAS ABLE TO MAKE
A BIT OF SMALL PROGRESS INLAND (BASICALLY SOUTH OF TAMPA
BAY)...THIS CONVERGENCE WAS EFFICIENT AND THUNDERSTORMS ERUPTED
VERY CLOSE TO THE COAST LATE IN THE AFTERNOON. TODAY...THE FLOW
JUST ABOVE THE SURFACE APPEARS LIGHT ENOUGH TO ALLOW THIS MORE
EFFICIENT CONVERGENCE TO OCCUR ALONG MUCH...IF NOT ALL OF THE
FLORIDA WEST COAST. THEREFORE...THINK WE WILL SEE THE ACTIVE
CONVECTION EXPAND NORTHWARD TODAY INTO THE TAMPA BAY AREA...AND
EVEN NORTHWARD THROUGH QUITE A BIT OF THE NATURE COAST. THE LAST
SEVERAL HRRR GUIDANCE RUNS THIS MORNING HAVE BEEN VERY AGGRESSIVE
WITH THE CONVECTION ALONG OUR ENTIRE I-75 CORRIDOR...AND GIVEN THE
FAVORABLE SYNOPTICS...SEE LITTLE REASON TO DISAGREE WITH ITS
GENERAL OUTPUT. RAIN CHANCES IN THE 60-70% RANGE SEEM REASONABLE
ALONG THE GENERAL I-75 CORRIDOR NORTHWARD TO NEAR BROOKSVILLE...
AND THEN WILL HAVE 50% FOR THE FAR NORTHERN ZONES. BTW...THE HRRR
DID A VERY GOOD JOB WITH THE PLACEMENT AND TIMING OF THE
CONVECTION ON SATURDAY...SHOWING CONVECTIVE COVERAGE MAINLY
EXTENDING FROM MANATEE COUNTY SOUTHWARD ALONG THE COAST DURING
THE MORNING RUNS. THIS VERIFIED VERY WELL.

THERE IS NOT A WHOLE LOT OF MOTION IN THE ATMOSPHERE SITTING UNDER
THE MIDDLE OF THE UPPER RIDGE...AND THEREFORE STORMS ARE NOT GOING
TO BE FAST MOVERS...PROPELLED ALONG BY WEAK FLOW...AND/OR OUTFLOW
BOUNDARY MOVEMENT. THE GENERAL MOTION SHOULD BE TOWARD THE COAST
AND EVENTUALLY OFFSHORE. HOWEVER...THE SLOW MOTION IS GOING TO
RESULT IN A HEAVY RAIN/LOCALIZED FLOODING THREAT. ALL OF THE
CONVECTION ALLOWING GUIDANCE IS SHOWING THE POTENTIAL FOR
IMPRESSIVE UPDRAFT VELOCITY VALUES AS WELL (MAXIMUM VALUES ON THE
ORDER OF 14-18M/S). THE STRONG UPDRAFTS WOULD BE CORRELATED WITH
VERY EFFICIENT LIGHTING PRODUCTION AS WELL.

ACTIVITY LINGERS INTO THE EVENING HOURS...AND MAY EVEN PEAK IN
SOME SPOTS BETWEEN 6-9PM. THEREAFTER...MOST GUIDANCE MEMBERS SHOW
THE STORMS MIGRATING OFFSHORE INTO THE EASTERN GULF AND WEAKENING.
WILL SLOWLY RAMP DOWN POPS NEAR THE COAST THROUGH THE MID/LATE
EVENING...AND RETURN ALL AREAS TO A DRY FORECAST AFTER MIDNIGHT.
THE LOW LEVEL MOISTURE WILL KEEP US SEASONABLY WARM OVERNIGHT...
WITH MOST SPOTS SEEING LOW TEMPS BY SUNRISE IN THE UPPER 60S TO
LOWER 70S.

&&

.AVIATION...
VFR CONDITIONS LATE THIS MORNING ACROSS WEST-CENTRAL FLORIDA.
SCT-BKN CUMULUS FIELD HAS ALREADY DEVELOPED AND WILL BE WITH US
THE REST OF THE DAY...WITH BASES RAISING FROM AROUND 3KFT TO 5KFT
THROUGH THE AFTERNOON. THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG
THE I-75 CORRIDOR THIS AFTERNOON AND PROGRESS WESTWARD TOWARD THE
COAST AFTER DEVELOPMENT. HAVE INCLUDED TEMPOS FOR THE EXPECTED
CONVECTION. ACTIVITY WILL PROGRESS OFFSHORE BY LATE EVENING.

&&

.MARINE...
GENERAL EAST TO SOUTHEAST WINDS WILL REMAIN IN PLACE THROUGH THE
REST OF TODAY WITH WINDS TURNING ONSHORE FOR A TIME THE COAST THIS
AFTERNOON. SHOWERS AND THUNDERSTORMS THAT DEVELOP OVER THE LAND
TODAY WILL SHIFT WESTWARD TOWARD THE COASTAL WATERS EARLY THIS
EVENING. BOATERS ON THE COASTAL WATERS AND BAYS SHOULD KEEP A
CLOSE WATCH ON THE WEATHER AND BE PREPARED TO SEEK SAFE HARBOR
QUICKLY...AS STORMS ARE LIKELY TO RAPIDLY DEVELOP AND MOVE
OFFSHORE. BY TUESDAY AND THROUGH THE REST OF THE WEEK...WIND FLOW
WILL BECOME MORE WESTERLY...AND KEEP THE MAJORITY OF THE STORMS
INLAND. WINDS AND SEAS ARE EXPECTED TO REMAIN BELOW HEADLINE
CRITERIA.

&&

.PRELIMINARY POINT TEMPS/POPS...
TPA  89  73  89  74 /  70  50  40  30
FMY  90  71  91  73 /  70  40  40  30
GIF  90  72  91  72 /  50  10  40  10
SRQ  88  72  88  73 /  60  50  20  30
BKV  90  70  90  69 /  60  40  40  30
SPG  88  75  89  76 /  60  50  20  30

&&

.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&

$$

SYNOPSIS/UPDATE/AVIATION/MARINE...14/MROCZKA
DECISION SUPPORT...RUDE




AREA FORECAST DISCUSSION

NWS LINCOLN IL

 256 PM CDT SUN MAY 17 2015

.SHORT TERM...(TONIGHT)
ISSUED AT 256 PM CDT SUN MAY 17 2015

POTENTIAL FOR SEVERE WEATHER THIS AFTERNOON/EVENING IS STILL BEING
MONITORED...HOWEVER IT IS BEGINNING TO LOOK LIKE ANY SEVERE WILL BE
ISOLATED AT BEST.  18Z KILX UPPER AIR SOUNDING SHOWS SBCAPE OF
2000J/KG AND 0-6KM BULK SHEAR OF 35KT: HOWEVER, A WARM LAYER AT
AROUND 900MB IS KEEPING THE ATMOSPHERE MOSTLY CAPPED.  REGIONAL
MESOSCALE ANALYSIS INDICATES A POCKET OF GREATER INSTABILITY ACROSS
NORTH-CENTRAL ILLINOIS FROM PEORIA/BLOOMINGTON NORTHWARD...MAKING
THIS THE PRIMARY SPOT FOR POTENTIAL CONVECTIVE DEVELOPMENT OVER THE
NEXT COUPLE OF HOURS.  HRRR SHOWS THIS SCENARIO UNFOLDING...WITH
SCATTERED STORMS LIFTING NORTHWARD INTO NORTHERN ILLINOIS/SOUTHERN
WISCONSIN LATER THIS AFTERNOON.  FURTHER SOUTH...THE UPSTREAM
AIRMASS ACROSS MISSOURI/SOUTHWEST ILLINOIS REMAINS STABLE AND CAPPED
IN THE WAKE OF A MORNING OUTFLOW BOUNDARY THAT HAS PUSHED WELL TO
THE EAST INTO WESTERN SECTIONS OF KENTUCKY AND TENNESSEE.  END
RESULT WILL LIKELY BE ONLY WIDELY SCATTERED STORMS DEVELOPING ALONG
THE I-55 CORRIDOR AFTER 21Z...WITH MINIMAL SEVERE WEATHER THREAT.
HIGH-RES MODELS CONTINUE TO SUGGEST CONVECTION WILL RE-DEVELOP OVER
SOUTHEAST MISSOURI/ARKANSAS THIS EVENING...THEN LIFT INTO SOUTHEAST
ILLINOIS TONIGHT.  PARTIAL CLEARING HAS OCCURRED ACROSS THIS
AREA...HOWEVER AIRMASS REMAINS STABLE BEHIND THE PREVIOUS OUTFLOW
BOUNDARY...SO AM SKEPTICAL OF THIS SOLUTION.  WILL CONTINUE TO
MONITOR SOUTHEAST MISSOURI FOR DEVELOPMENT OVER THE NEXT SEVERAL
HOURS.  AT THIS TIME...WILL CARRY ONLY SLIGHT OR LOW CHANCE POPS
WEST OF THE I-57 CORRIDOR THROUGH THE EVENING HOURS...WITH DRY
CONDITIONS OVERNIGHT.  FURTHER EAST...WILL GO WITH HIGHER POPS IN
THE HIGHER DEWPOINT/MORE UNSTABLE AIRMASS ALONG/EAST OF I-57.

&&

.LONG TERM...(MONDAY THROUGH SUNDAY)
ISSUED AT 256 PM CDT SUN MAY 17 2015

COLD FRONT WILL PASS THROUGH CENTRAL ILLINOIS ON MONDAY...DROPPING
SOUTH OF THE I-70 CORRIDOR BY LATE AFTERNOON.  SCATTERED SHOWERS AND
THUNDERSTORMS MAY DEVELOP AHEAD OF THE FRONT...HOWEVER AREAL
COVERAGE WILL BE GREATEST FURTHER EAST ACROSS THE OHIO RIVER VALLEY.
WILL MAINTAIN CHANCE POPS ALONG/EAST OF A DANVILLE TO SHELBYVILLE
LINE THROUGHOUT THE DAY UNTIL THE BOUNDARY EXITS.  HIGH PRESSURE
WILL TAKE CONTROL OF THE WEATHER BEHIND THE DEPARTING
FRONT...PROVIDING COOL/DRY WEATHER FOR TUESDAY.  RESULTING HIGH
TEMPERATURES WILL REMAIN IN THE LOWER TO MIDDLE 60S...WHILE
OVERNIGHT LOWS DIP INTO THE 40S.

PIECE OF ENERGY IS EXPECTED TO EJECT FROM WESTERN CONUS UPPER LOW BY
MID-WEEK...BRINGING CLOUDS AND PERHAPS A FEW SHOWERS INTO THE AREA
ON WEDNESDAY.  MODELS DEPICT A WEAKENING WAVE COMING INTO A VERY DRY
AIRMASS...SO THINK ANY RAINFALL WILL BE QUITE LIGHT.  HAVE CUT BACK
ON POPS...FEATURING LIKELY ACROSS THE FAR SOUTHWEST CWA AROUND
JACKSONVILLE TAPERING DOWN TO JUST SLIGHT ALONG THE INDIANA BORDER.
ONCE THIS WAVE DEPARTS...COOL/DRY WEATHER WILL RETURN FOR THURSDAY
AND FRIDAY.

MAIN UPPER LOW WILL GRADUALLY LIFT INTO THE PLAINS LATE IN THE
PERIOD...BRINGING THE NEXT SIGNIFICANT CHANCE FOR RAIN BY LATE IN
THE WEEKEND.  WHILE MODEL DIFFERENCES STILL EXIST...GFS/ECMWF
CONSENSUS POINTS TO THE SUNDAY/MONDAY TIME FRAME AS THE PRIMARY TIME
FOR SHOWERS AND THUNDERSTORMS.  HAVE THEREFORE KEPT RAIN CHANCES OUT
OF THE FORECAST FOR SATURDAY...THEN HAVE HIT POPS HARD FOR SUNDAY.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1238 PM CDT SUN MAY 17 2015

MAIN CONCERN WILL BE WITH CONVECTIVE CHANCES THIS AFTERNOON.
MODELS HAVE BEEN STRUGGLING TO AGREE ON WHERE EXACTLY THIS WILL
TAKE PLACE...SO WILL GENERALLY MAINTAIN THE VCTS MENTIONS WITH
JUST SOME SLIGHT ADJUSTMENTS TO TIMING BASED ON CURRENT RADAR.
HAVE INCLUDED A TEMPO PERIOD OF MVFR CONDITIONS AT KCMI/KDEC AS
THEY ARE MORE LIKELY TO SEE DEVELOPMENT FROM AN AREA OF
SHOWERS/STORMS CURRENTLY IN FAR SOUTHERN ILLINOIS. SOUTHERLY WINDS
HAVE BEEN FREQUENTLY GUSTING 25-30 KNOTS...AIDED BY SOME BREAKS IN
THE CLOUDS...BUT THESE WILL SUBSIDE A TAD THROUGH THE AFTERNOON AS
CLOUD COVER THICKENS AGAIN. HOWEVER...THE GUSTINESS WILL NOT
SUBSIDE UNTIL CLOSER TO SUNSET. WINDS EXPECTED TO DIMINISH AND
BECOME SOUTHWEST OVERNIGHT...BEFORE TRENDING MORE WESTERLY LATE IN
THE TAF PERIOD AS A COLD FRONT ARRIVES LATE MORNING.


&&

.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...GEELHART




AREA FORECAST DISCUSSION

NWS LINCOLN IL

 1238 PM CDT SUN MAY 17 2015

.UPDATE...
ISSUED AT 1008 AM CDT SUN MAY 17 2015

STILL QUITE A FEW QUESTIONS IN REGARDS TO SEVERE WEATHER POTENTIAL
TODAY. EARLIER LINE OF SHOWERS FIZZLED OUT AS IT PASSED I-55...
AND THE REMNANTS ARE LOCATED BETWEEN DECATUR AND CHAMPAIGN PER
LATEST RADAR IMAGERY. GOOD-SIZED CLEAR SLOT ADVANCING ACROSS THE
STATE AT THE MOMENT AND IS RESULTING IN SOME BRIEF SUNNY SKIES
OVER THE NORTHWEST HALF OF THE FORECAST AREA. THIS SHOULD HELP
DESTABILIZE THINGS ACROSS THAT AREA OVER THE NEXT HOUR OR TWO...
AND WE WILL BE DOING A SPECIAL SOUNDING AT NOON TO SAMPLE THE
CHANGES. RAP GUIDANCE SUGGESTING IT MAY TAKE UNTIL EARLY AFTERNOON
TO GET CAPE`S ABOVE 1000 J/KG FURTHER SOUTH. BEST BULK SHEAR TO BE
LOCATED WEST OF I-55...BUT LATEST RAP AND THE 12Z NAM INDICATE
THE BEST POTENTIAL FOR DEVELOPMENT WILL BE EAST OF THERE NEAR THE
REMNANTS OF THE MORNING ACTIVITY. HOWEVER...THE RECENTLY ARRIVED
14Z HRRR IS NOW STARTING TO SHOW SOME ACTIVITY MOVING UP THE
ILLINOIS RIVER VALLEY BEGINNING AROUND 3 PM. SHOWERS IN SOUTHEAST
MISSOURI STARTING TO CROSS INTO SOUTHERN ILLINOIS AS WELL...AND
ANY BOUNDARIES/VORTICES ASSOCIATED WITH THIS AREA MAY COME INTO
PLAY AS WELL.

HAVE SENT OUT SOME REFINEMENTS TO THE POP`S FOR TODAY AND TONIGHT
TO INCORPORATE THE LATEST TRENDS. LITTLE CHANGE TO HIGH
TEMPERATURE AT THE MOMENT.

&&

.SHORT TERM...(TODAY)
ISSUED AT 335 AM CDT SUN MAY 17 2015

ANOTHER UNSEASONABLY WARM & MUGGY DAY WITH SOUTHERLY WINDS IS ON TAP
FOR CENTRAL AND SOUTHEAST ILLINOIS TODAY. THIS GENERAL SCENARIO HAS
NOT CHANGED MUCH SINCE YESTERDAY. THE PRIMARY CHANGE EXPECTED FOR
TODAY IS THAT STRONGER DEEP-LAYER SHEAR WILL BE PRESENT, WITH AN
ASSOCIATED INCREASE IN ORGANIZED CONVECTION. THIS WILL BE A CHANGE
FROM THE MOSTLY DISORGANIZED SHOWERS/THUNDERSTORMS OF THE PAST
COUPLE OF DAYS. UNFORTUNATELY, THERE IS QUITE A BIT OF DISAGREEMENT
IN THE CONVECTIVE DETAILS TODAY AMONG THE GUIDANCE. DIFFERENCES ARE
NOT SURPRISING WITH THE SYNOPTIC SCALE MODELS, BUT THEY ARE ALSO
PRESENT IN THE HIGHER RESOLUTION OUTPUT AS WELL. UNDOUBTEDLY, THE
ULTIMATE OUTCOME WILL PROBABLY BE MODULATED BY BOUNDARIES FROM
UPSTREAM CONVECTION THAT MAKES IT INTO AREA AND ASSOCIATED CLOUD
COVER OR LACK THEREOF.

THE REMNANTS OF A PLAINS SQUALL LINE WILL BEGIN TO SPREAD INTO THE
WESTERN PORTION OF THE FORECAST AREA WITHIN THE NEXT COUPLE OF
HOURS. HRRR AND RAP GUIDANCE SUGGEST A RAPID WEAKENING OF THE
STORMS, AND THERE HAS BEEN SIGNIFICANT WEAKENING OF LATE IN RECENT
RADAR LOOPS, AS WELL AS WARMING CLOUD TOPS. THE REMNANTS OF THIS
SYSTEM WILL LIKELY BE KEY TO WHERE THINGS FOCUS IN THE FORECAST AREA
TODAY. MODELS HAVE CONSISTENTLY SUGGESTED CAPE VALUES FROM 1500-2500
J/KG IN THE FORECAST AREA DURING PEAK HEATING TODAY, WHILE BULK
SHEAR VALUES SHOULD BE 35-45 KTS WEST AND 25-35 KTS EAST. THESE
PARAMETERS SUGGEST SOME STRONG TO SEVERE STORMS ARE POSSIBLE IN THE
AREA TODAY, BUT THE EXACT LOCATION/TIMING OF DEVELOPMENT WILL NOT BE
A HIGH CONFIDENCE FORECAST UNTIL WE SEE HOW THINGS PLAY OUT WITH THE
REMNANTS MOVING INTO OUR AREA.

.LONG TERM...(TONIGHT THROUGH SATURDAY)
ISSUED AT 335 AM CDT SUN MAY 17 2015

00Z FORECAST MODELS TAKE 558 DM 500 MB LOW OVER CENTRAL NEBRASKA NE
INTO NORTHERN MN BY 12Z/MON WHILE 992 MB SURFACE LOW PRESSURE OVER
CENTRAL SD WEAKENS AS IT TRACKS NE INTO NORTHERN MN BY DAWN MONDAY.
THIS WILL BRING AN OCCLUDED FRONT EAST INTO CENTRAL IL NEAR I-55
BY 18Z/MON AND NEARING THE WABASH RIVER BY 00Z/TUE. HIGHEST
CHANCES OF SHOWERS AND THUNDERSTORMS WILL SHIFT INTO EASTERN IL
TONIGHT AND MONDAY. SPC HAS SLIGHT RISK OF SEVERE STORMS OVER ALL
BY FAR SE IL NEAR WABASH RIVER THIS AFTERNOON/EVENING WITH 15%
RISK OF LARGE HAIL AND DAMAGING WIND GUSTS AND 2-5% RISK OF
TORNADOES AND HIGHEST RISK (5%) OVER KNOX...STARK AND MARSHALL
COUNTIES. SPC KEEPS MARGINAL RISK OF SEVERE STORMS MONDAY EAST OF
IL OVER CENTRAL AND EASTERN INDIANA. MILD LOWS TONIGHT IN THE MID
TO UPPER 60S WITH SSW BREEZES. ANOTHER WARM DAY MONDAY WITH HIGHS
IN THE UPPER 70S WEST OF THE IL RIVER AND LOWER 80S EAST OF THE IL
RIVER. SW WINDS TURN WEST AND NW BEHIND COLD FRONT AND DEWPOINTS
WILL BE DROPPING BEHIND THE FRONT DURING THE DAY. THOUGH STAYING
HUMID DURING THE DAY MONDAY OVER SOUTHEAST IL WITH DEWPOINTS IN
THE UPPER 60S TO NEAR 70F.

LINGERED JUST SLIGHT CHANCE OF SHOWERS AND POSSIBLE THUNDERSTORM IN
FAR SE IL NEAR WABASH RIVER MONDAY EVENING. OTHERWISE DRY AND COOLER
AS CANADIAN HIGH PRESSURE SETTLES INTO THE MIDWEST BY TUE WITH A
FAIR AMOUNT OF SUNSHINE OVER CENTRAL/SE IL TUE WITH NW WINDS. LOWS
MON NIGHT RANGE FROM MID 40S OVER IL RIVER VALLEY TO MID 50S BY
LAWRENCEVILLE. HIGHS TUE RANGE FROM LOWER 60S NORTH OF I-74 TO
AROUND 70F BY LAWRENCEVILLE. ANOTHER COOL NIGHT TUE NIGHT WITH LOWS
IN THE MID TO UPPER 40S.

EXTENDED MODELS CONTINUE TO SHOW A DISTURBANCE EJECTING FROM THE
TROF/CUTOFF LOW NEAR CA INTO THE CENTRAL PLAINS WED AND BRINGING
MAINLY LIGHT QPF INTO CENTRAL AND SW IL WED AND SHIFTING IT
SOUTHWARD WED NIGHT AND THU. HAVE INCREASE POPS BY WED AFTERNOON TO
LIKELY FROM JACKSONVILLE SW WHILE LOWER POPS IN NE CWA BY DANVILLE.
MORE CLOUDS WED AND RAIN CHANCES TO KEEP IT COOLER WITH HIGHS IN
UPPER 50S AND LOWER 60S CENTRAL IL AND MID 60S SOUTHEAST OF I-70.

ANOTHER CANADIAN HIGH PRESSURE SETTLES INTO THE MIDWEST THU
RETURNING DRY WEATHER AND TEMPS MODERATING DUE TO MORE SUNSHINE WITH
HIGHS IN THE UPPER 60S. SEASONABLE HIGHS REACH THE LOW TO MID 70S
FRIDAY. LOOKS LIKE AN INCREASING CHANCE OF SHOWERS AND THUNDERSTORMS
DURING THE MEMORIAL DAY WEEKEND ESPECIALLY FROM SAT NIGHT ON WITH
DISTURBANCE EJECTING OUT OF SW UPPER LEVEL FLOW AND INCREASING TEMPS
AND HUMIDITY WITH SOUTHERLY FLOW RETURNING.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1238 PM CDT SUN MAY 17 2015

MAIN CONCERN WILL BE WITH CONVECTIVE CHANCES THIS AFTERNOON.
MODELS HAVE BEEN STRUGGLING TO AGREE ON WHERE EXACTLY THIS WILL
TAKE PLACE...SO WILL GENERALLY MAINTAIN THE VCTS MENTIONS WITH
JUST SOME SLIGHT ADJUSTMENTS TO TIMING BASED ON CURRENT RADAR.
HAVE INCLUDED A TEMPO PERIOD OF MVFR CONDITIONS AT KCMI/KDEC AS
THEY ARE MORE LIKELY TO SEE DEVELOPMENT FROM AN AREA OF
SHOWERS/STORMS CURRENTLY IN FAR SOUTHERN ILLINOIS. SOUTHERLY WINDS
HAVE BEEN FREQUENTLY GUSTING 25-30 KNOTS...AIDED BY SOME BREAKS IN
THE CLOUDS...BUT THESE WILL SUBSIDE A TAD THROUGH THE AFTERNOON AS
CLOUD COVER THICKENS AGAIN. HOWEVER...THE GUSTINESS WILL NOT
SUBSIDE UNTIL CLOSER TO SUNSET. WINDS EXPECTED TO DIMINISH AND
BECOME SOUTHWEST OVERNIGHT...BEFORE TRENDING MORE WESTERLY LATE IN
THE TAF PERIOD AS A COLD FRONT ARRIVES LATE MORNING.

&&

.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE...GEELHART
SHORT TERM...07/BAK
LONG TERM...07
AVIATION...GEELHART




AREA FORECAST DISCUSSION

NWS LINCOLN IL

 1009 AM CDT SUN MAY 17 2015

.UPDATE...
ISSUED AT 1008 AM CDT SUN MAY 17 2015

STILL QUITE A FEW QUESTIONS IN REGARDS TO SEVERE WEATHER POTENTIAL
TODAY. EARLIER LINE OF SHOWERS FIZZLED OUT AS IT PASSED I-55...
AND THE REMNANTS ARE LOCATED BETWEEN DECATUR AND CHAMPAIGN PER
LATEST RADAR IMAGERY. GOOD-SIZED CLEAR SLOT ADVANCING ACROSS THE
STATE AT THE MOMENT AND IS RESULTING IN SOME BRIEF SUNNY SKIES
OVER THE NORTHWEST HALF OF THE FORECAST AREA. THIS SHOULD HELP
DESTABILIZE THINGS ACROSS THAT AREA OVER THE NEXT HOUR OR TWO...
AND WE WILL BE DOING A SPECIAL SOUNDING AT NOON TO SAMPLE THE
CHANGES. RAP GUIDANCE SUGGESTING IT MAY TAKE UNTIL EARLY AFTERNOON
TO GET CAPE`S ABOVE 1000 J/KG FURTHER SOUTH. BEST BULK SHEAR TO BE
LOCATED WEST OF I-55...BUT LATEST RAP AND THE 12Z NAM INDICATE
THE BEST POTENTIAL FOR DEVELOPMENT WILL BE EAST OF THERE NEAR THE
REMNANTS OF THE MORNING ACTIVITY. HOWEVER...THE RECENTLY ARRIVED
14Z HRRR IS NOW STARTING TO SHOW SOME ACTIVITY MOVING UP THE
ILLINOIS RIVER VALLEY BEGINNING AROUND 3 PM. SHOWERS IN SOUTHEAST
MISSOURI STARTING TO CROSS INTO SOUTHERN ILLINOIS AS WELL...AND
ANY BOUNDARIES/VORTICES ASSOCIATED WITH THIS AREA MAY COME INTO
PLAY AS WELL.

HAVE SENT OUT SOME REFINEMENTS TO THE POP`S FOR TODAY AND TONIGHT
TO INCORPORATE THE LATEST TRENDS. LITTLE CHANGE TO HIGH
TEMPERATURE AT THE MOMENT.

&&

.SHORT TERM...(TODAY)
ISSUED AT 335 AM CDT SUN MAY 17 2015

ANOTHER UNSEASONABLY WARM & MUGGY DAY WITH SOUTHERLY WINDS IS ON TAP
FOR CENTRAL AND SOUTHEAST ILLINOIS TODAY. THIS GENERAL SCENARIO HAS
NOT CHANGED MUCH SINCE YESTERDAY. THE PRIMARY CHANGE EXPECTED FOR
TODAY IS THAT STRONGER DEEP-LAYER SHEAR WILL BE PRESENT, WITH AN
ASSOCIATED INCREASE IN ORGANIZED CONVECTION. THIS WILL BE A CHANGE
FROM THE MOSTLY DISORGANIZED SHOWERS/THUNDERSTORMS OF THE PAST
COUPLE OF DAYS. UNFORTUNATELY, THERE IS QUITE A BIT OF DISAGREEMENT
IN THE CONVECTIVE DETAILS TODAY AMONG THE GUIDANCE. DIFFERENCES ARE
NOT SURPRISING WITH THE SYNOPTIC SCALE MODELS, BUT THEY ARE ALSO
PRESENT IN THE HIGHER RESOLUTION OUTPUT AS WELL. UNDOUBTEDLY, THE
ULTIMATE OUTCOME WILL PROBABLY BE MODULATED BY BOUNDARIES FROM
UPSTREAM CONVECTION THAT MAKES IT INTO AREA AND ASSOCIATED CLOUD
COVER OR LACK THEREOF.

THE REMNANTS OF A PLAINS SQUALL LINE WILL BEGIN TO SPREAD INTO THE
WESTERN PORTION OF THE FORECAST AREA WITHIN THE NEXT COUPLE OF
HOURS. HRRR AND RAP GUIDANCE SUGGEST A RAPID WEAKENING OF THE
STORMS, AND THERE HAS BEEN SIGNIFICANT WEAKENING OF LATE IN RECENT
RADAR LOOPS, AS WELL AS WARMING CLOUD TOPS. THE REMNANTS OF THIS
SYSTEM WILL LIKELY BE KEY TO WHERE THINGS FOCUS IN THE FORECAST AREA
TODAY. MODELS HAVE CONSISTENTLY SUGGESTED CAPE VALUES FROM 1500-2500
J/KG IN THE FORECAST AREA DURING PEAK HEATING TODAY, WHILE BULK
SHEAR VALUES SHOULD BE 35-45 KTS WEST AND 25-35 KTS EAST. THESE
PARAMETERS SUGGEST SOME STRONG TO SEVERE STORMS ARE POSSIBLE IN THE
AREA TODAY, BUT THE EXACT LOCATION/TIMING OF DEVELOPMENT WILL NOT BE
A HIGH CONFIDENCE FORECAST UNTIL WE SEE HOW THINGS PLAY OUT WITH THE
REMNANTS MOVING INTO OUR AREA.

.LONG TERM...(TONIGHT THROUGH SATURDAY)
ISSUED AT 335 AM CDT SUN MAY 17 2015

00Z FORECAST MODELS TAKE 558 DM 500 MB LOW OVER CENTRAL NEBRASKA NE
INTO NORTHERN MN BY 12Z/MON WHILE 992 MB SURFACE LOW PRESSURE OVER
CENTRAL SD WEAKENS AS IT TRACKS NE INTO NORTHERN MN BY DAWN MONDAY.
THIS WILL BRING AN OCCLUDED FRONT EAST INTO CENTRAL IL NEAR I-55
BY 18Z/MON AND NEARING THE WABASH RIVER BY 00Z/TUE. HIGHEST
CHANCES OF SHOWERS AND THUNDERSTORMS WILL SHIFT INTO EASTERN IL
TONIGHT AND MONDAY. SPC HAS SLIGHT RISK OF SEVERE STORMS OVER ALL
BY FAR SE IL NEAR WABASH RIVER THIS AFTERNOON/EVENING WITH 15%
RISK OF LARGE HAIL AND DAMAGING WIND GUSTS AND 2-5% RISK OF
TORNADOES AND HIGHEST RISK (5%) OVER KNOX...STARK AND MARSHALL
COUNTIES. SPC KEEPS MARGINAL RISK OF SEVERE STORMS MONDAY EAST OF
IL OVER CENTRAL AND EASTERN INDIANA. MILD LOWS TONIGHT IN THE MID
TO UPPER 60S WITH SSW BREEZES. ANOTHER WARM DAY MONDAY WITH HIGHS
IN THE UPPER 70S WEST OF THE IL RIVER AND LOWER 80S EAST OF THE IL
RIVER. SW WINDS TURN WEST AND NW BEHIND COLD FRONT AND DEWPOINTS
WILL BE DROPPING BEHIND THE FRONT DURING THE DAY. THOUGH STAYING
HUMID DURING THE DAY MONDAY OVER SOUTHEAST IL WITH DEWPOINTS IN
THE UPPER 60S TO NEAR 70F.

LINGERED JUST SLIGHT CHANCE OF SHOWERS AND POSSIBLE THUNDERSTORM IN
FAR SE IL NEAR WABASH RIVER MONDAY EVENING. OTHERWISE DRY AND COOLER
AS CANADIAN HIGH PRESSURE SETTLES INTO THE MIDWEST BY TUE WITH A
FAIR AMOUNT OF SUNSHINE OVER CENTRAL/SE IL TUE WITH NW WINDS. LOWS
MON NIGHT RANGE FROM MID 40S OVER IL RIVER VALLEY TO MID 50S BY
LAWRENCEVILLE. HIGHS TUE RANGE FROM LOWER 60S NORTH OF I-74 TO
AROUND 70F BY LAWRENCEVILLE. ANOTHER COOL NIGHT TUE NIGHT WITH LOWS
IN THE MID TO UPPER 40S.

EXTENDED MODELS CONTINUE TO SHOW A DISTURBANCE EJECTING FROM THE
TROF/CUTOFF LOW NEAR CA INTO THE CENTRAL PLAINS WED AND BRINGING
MAINLY LIGHT QPF INTO CENTRAL AND SW IL WED AND SHIFTING IT
SOUTHWARD WED NIGHT AND THU. HAVE INCREASE POPS BY WED AFTERNOON TO
LIKELY FROM JACKSONVILLE SW WHILE LOWER POPS IN NE CWA BY DANVILLE.
MORE CLOUDS WED AND RAIN CHANCES TO KEEP IT COOLER WITH HIGHS IN
UPPER 50S AND LOWER 60S CENTRAL IL AND MID 60S SOUTHEAST OF I-70.

ANOTHER CANADIAN HIGH PRESSURE SETTLES INTO THE MIDWEST THU
RETURNING DRY WEATHER AND TEMPS MODERATING DUE TO MORE SUNSHINE WITH
HIGHS IN THE UPPER 60S. SEASONABLE HIGHS REACH THE LOW TO MID 70S
FRIDAY. LOOKS LIKE AN INCREASING CHANCE OF SHOWERS AND THUNDERSTORMS
DURING THE MEMORIAL DAY WEEKEND ESPECIALLY FROM SAT NIGHT ON WITH
DISTURBANCE EJECTING OUT OF SW UPPER LEVEL FLOW AND INCREASING TEMPS
AND HUMIDITY WITH SOUTHERLY FLOW RETURNING.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 654 AM CDT SUN MAY 17 2015

AREAS OF IFR/MVFR CONDITIONS WILL BE EVIDENT ACROSS THE CENTRAL
AND SOUTHEAST ILLINOIS TERMINAL AREA TO START THE DAY. A WEAKENING
BAND OF SHOWERS, CURRENTLY SPREADING ACROSS CENTRAL ILLINOIS, MAY
ALSO IMPACT A FEW TAF SITES WITHIN THE NEXT FEW HOURS. CONDITIONS
SHOULD GENERALLY IMPROVE TO VFR BY LATER THIS MORNING, AND THEN WE
WILL HAVE TO WAIT FOR DIURNALLY ENHANCED SHOWERS/STORMS TO
DEVELOP. THE EXACT TIMING AND LOCATION FOR THIS DIURNAL
DEVELOPMENT IS UNCLEAR AT THIS TIME, SO HAVE ONLY INCLUDED A VCTS
MENTION THIS AFTERNOON/EARLY EVENING. GUSTY SOUTHERLY WINDS WILL
DEVELOP FOR MUCH OF THE DAYTIME HOURS TODAY AS WELL. THE
PRECIPITATION CHANCES SHOULD WANE THIS EVENING, WITH VFR
CONDITIONSPERSISTING FOR MUCH OF THE NIGHT. HOWEVER, MVFR FOG,
AND POSSIBLY STRATUS, SHOULD DEVELOP AFTER MIDNIGHT TONIGHT (05Z
MONDAY).

&&

.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE...GEELHART
SHORT TERM...07/BAK
LONG TERM...07
AVIATION...BAK



AREA FORECAST DISCUSSION

NWS LINCOLN IL

 659 AM CDT SUN MAY 17 2015

.SHORT TERM...(TODAY)
ISSUED AT 335 AM CDT SUN MAY 17 2015

ANOTHER UNSEASONABLY WARM & MUGGY DAY WITH SOUTHERLY WINDS IS ON TAP
FOR CENTRAL AND SOUTHEAST ILLINOIS TODAY. THIS GENERAL SCENARIO HAS
NOT CHANGED MUCH SINCE YESTERDAY. THE PRIMARY CHANGE EXPECTED FOR
TODAY IS THAT STRONGER DEEP-LAYER SHEAR WILL BE PRESENT, WITH AN
ASSOCIATED INCREASE IN ORGANIZED CONVECTION. THIS WILL BE A CHANGE
FROM THE MOSTLY DISORGANIZED SHOWERS/THUNDERSTORMS OF THE PAST
COUPLE OF DAYS. UNFORTUNATELY, THERE IS QUITE A BIT OF DISAGREEMENT
IN THE CONVECTIVE DETAILS TODAY AMONG THE GUIDANCE. DIFFERENCES ARE
NOT SURPRISING WITH THE SYNOPTIC SCALE MODELS, BUT THEY ARE ALSO
PRESENT IN THE HIGHER RESOLUTION OUTPUT AS WELL. UNDOUBTEDLY, THE
ULTIMATE OUTCOME WILL PROBABLY BE MODULATED BY BOUNDARIES FROM
UPSTREAM CONVECTION THAT MAKES IT INTO AREA AND ASSOCIATED CLOUD
COVER OR LACK THEREOF.

THE REMNANTS OF A PLAINS SQUALL LINE WILL BEGIN TO SPREAD INTO THE
WESTERN PORTION OF THE FORECAST AREA WITHIN THE NEXT COUPLE OF
HOURS. HRRR AND RAP GUIDANCE SUGGEST A RAPID WEAKENING OF THE
STORMS, AND THERE HAS BEEN SIGNIFICANT WEAKENING OF LATE IN RECENT
RADAR LOOPS, AS WELL AS WARMING CLOUD TOPS. THE REMNANTS OF THIS
SYSTEM WILL LIKELY BE KEY TO WHERE THINGS FOCUS IN THE FORECAST AREA
TODAY. MODELS HAVE CONSISTENTLY SUGGESTED CAPE VALUES FROM 1500-2500
J/KG IN THE FORECAST AREA DURING PEAK HEATING TODAY, WHILE BULK
SHEAR VALUES SHOULD BE 35-45 KTS WEST AND 25-35 KTS EAST. THESE
PARAMETERS SUGGEST SOME STRONG TO SEVERE STORMS ARE POSSIBLE IN THE
AREA TODAY, BUT THE EXACT LOCATION/TIMING OF DEVELOPMENT WILL NOT BE
A HIGH CONFIDENCE FORECAST UNTIL WE SEE HOW THINGS PLAY OUT WITH THE
REMNANTS MOVING INTO OUR AREA.

.LONG TERM...(TONIGHT THROUGH SATURDAY)
ISSUED AT 335 AM CDT SUN MAY 17 2015

00Z FORECAST MODELS TAKE 558 DM 500 MB LOW OVER CENTRAL NEBRASKA NE
INTO NORTHERN MN BY 12Z/MON WHILE 992 MB SURFACE LOW PRESSURE OVER
CENTRAL SD WEAKENS AS IT TRACKS NE INTO NORTHERN MN BY DAWN MONDAY.
THIS WILL BRING AN OCCLUDED FRONT EAST INTO CENTRAL IL NEAR I-55
BY 18Z/MON AND NEARING THE WABASH RIVER BY 00Z/TUE. HIGHEST
CHANCES OF SHOWERS AND THUNDERSTORMS WILL SHIFT INTO EASTERN IL
TONIGHT AND MONDAY. SPC HAS SLIGHT RISK OF SEVERE STORMS OVER ALL
BY FAR SE IL NEAR WABASH RIVER THIS AFTERNOON/EVENING WITH 15%
RISK OF LARGE HAIL AND DAMAGING WIND GUSTS AND 2-5% RISK OF
TORNADOES AND HIGHEST RISK (5%) OVER KNOX...STARK AND MARSHALL
COUNTIES. SPC KEEPS MARGINAL RISK OF SEVERE STORMS MONDAY EAST OF
IL OVER CENTRAL AND EASTERN INDIANA. MILD LOWS TONIGHT IN THE MID
TO UPPER 60S WITH SSW BREEZES. ANOTHER WARM DAY MONDAY WITH HIGHS
IN THE UPPER 70S WEST OF THE IL RIVER AND LOWER 80S EAST OF THE IL
RIVER. SW WINDS TURN WEST AND NW BEHIND COLD FRONT AND DEWPOINTS
WILL BE DROPPING BEHIND THE FRONT DURING THE DAY. THOUGH STAYING
HUMID DURING THE DAY MONDAY OVER SOUTHEAST IL WITH DEWPOINTS IN
THE UPPER 60S TO NEAR 70F.

LINGERED JUST SLIGHT CHANCE OF SHOWERS AND POSSIBLE THUNDERSTORM IN
FAR SE IL NEAR WABASH RIVER MONDAY EVENING. OTHERWISE DRY AND COOLER
AS CANADIAN HIGH PRESSURE SETTLES INTO THE MIDWEST BY TUE WITH A
FAIR AMOUNT OF SUNSHINE OVER CENTRAL/SE IL TUE WITH NW WINDS. LOWS
MON NIGHT RANGE FROM MID 40S OVER IL RIVER VALLEY TO MID 50S BY
LAWRENCEVILLE. HIGHS TUE RANGE FROM LOWER 60S NORTH OF I-74 TO
AROUND 70F BY LAWRENCEVILLE. ANOTHER COOL NIGHT TUE NIGHT WITH LOWS
IN THE MID TO UPPER 40S.

EXTENDED MODELS CONTINUE TO SHOW A DISTURBANCE EJECTING FROM THE
TROF/CUTOFF LOW NEAR CA INTO THE CENTRAL PLAINS WED AND BRINGING
MAINLY LIGHT QPF INTO CENTRAL AND SW IL WED AND SHIFTING IT
SOUTHWARD WED NIGHT AND THU. HAVE INCREASE POPS BY WED AFTERNOON TO
LIKELY FROM JACKSONVILLE SW WHILE LOWER POPS IN NE CWA BY DANVILLE.
MORE CLOUDS WED AND RAIN CHANCES TO KEEP IT COOLER WITH HIGHS IN
UPPER 50S AND LOWER 60S CENTRAL IL AND MID 60S SOUTHEAST OF I-70.

ANOTHER CANADIAN HIGH PRESSURE SETTLES INTO THE MIDWEST THU
RETURNING DRY WEATHER AND TEMPS MODERATING DUE TO MORE SUNSHINE WITH
HIGHS IN THE UPPER 60S. SEASONABLE HIGHS REACH THE LOW TO MID 70S
FRIDAY. LOOKS LIKE AN INCREASING CHANCE OF SHOWERS AND THUNDERSTORMS
DURING THE MEMORIAL DAY WEEKEND ESPECIALLY FROM SAT NIGHT ON WITH
DISTURBANCE EJECTING OUT OF SW UPPER LEVEL FLOW AND INCREASING TEMPS
AND HUMIDITY WITH SOUTHERLY FLOW RETURNING.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 654 AM CDT SUN MAY 17 2015

AREAS OF IFR/MVFR CONDTIONS WILL BE EVIDENT ACROSS THE CENTRAL AND
SOUTHEAST ILLINOIS TERMINAL AREA TO START THE DAY. A WEAKENING BAND
OF SHOWERS, CURRENTLY SPREADING ACROSS CENTRAL ILLINOIS, MAY ALSO
IMPACT A FEW TAF SITES WITHIN THE NEXT FEW HOURS. CONDTIONS SHOULD
GENERALLY IMPROVE TO VFR BY LATER THIS MORNING, AND THEN WE WILL
HAVE TO WAIT FOR DIURNALLY ENHANCED SHOWERS/STORMS TO DEVELOP. THE
EXACT TIMING AND LOCATION FOR THIS DIURNAL DEVELOPMENT IS UNCLEAR
AT THIS TIME, SO HAVE ONLY INCLUDED A VCTS MENTION THIS
AFTERNOON/EARLY EVENING. GUSTY SOUTHERLY WINDS WILL DEVELOP FOR
MUCH OF THE DAYTIME HOURS TODAY AS WELL. THE PRECIPITATION CHANCES
SHOULD WANE THIS EVENING, WITH VFR CONDTIONS PERSISTING FOR MUCH
OF THE NIGHT. HOWEVER, MVFR FOG, AND POSSIBLY STRATUS, SHOULD
DEVELOP AFTER MIDNIGHT TONIGHT (05Z MONDAY)

&&

.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...07/BAK
LONG TERM...07
AVIATION...BAK




AREA FORECAST DISCUSSION

NWS LINCOLN IL

 335 AM CDT SUN MAY 17 2015

.SHORT TERM...(TODAY)
ISSUED AT 335 AM CDT SUN MAY 17 2015

ANOTHER UNSEASONABLY WARM & MUGGY DAY WITH SOUTHERLY WINDS IS ON TAP
FOR CENTRAL AND SOUTHEAST ILLINOIS TODAY. THIS GENERAL SCENARIO HAS
NOT CHANGED MUCH SINCE YESTERDAY. THE PRIMARY CHANGE EXPECTED FOR
TODAY IS THAT STRONGER DEEP-LAYER SHEAR WILL BE PRESENT, WITH AN
ASSOCIATED INCREASE IN ORGANIZED CONVECTION. THIS WILL BE A CHANGE
FROM THE MOSTLY DISORGANIZED SHOWERS/THUNDERSTORMS OF THE PAST
COUPLE OF DAYS. UNFORTUNATELY, THERE IS QUITE A BIT OF DISAGREEMENT
IN THE CONVECTIVE DETAILS TODAY AMONG THE GUIDANCE. DIFFERENCES ARE
NOT SURPRISING WITH THE SYNOPTIC SCALE MODELS, BUT THEY ARE ALSO
PRESENT IN THE HIGHER RESOLUTION OUTPUT AS WELL. UNDOUBTEDLY, THE
ULTIMATE OUTCOME WILL PROBABLY BE MODULATED BY BOUNDARIES FROM
UPSTREAM CONVECTION THAT MAKES IT INTO AREA AND ASSOCIATED CLOUD
COVER OR LACK THEREOF.

THE REMNANTS OF A PLAINS SQUALL LINE WILL BEGIN TO SPREAD INTO THE
WESTERN PORTION OF THE FORECAST AREA WITHIN THE NEXT COUPLE OF
HOURS. HRRR AND RAP GUIDANCE SUGGEST A RAPID WEAKENING OF THE
STORMS, AND THERE HAS BEEN SIGNIFICANT WEAKENING OF LATE IN RECENT
RADAR LOOPS, AS WELL AS WARMING CLOUD TOPS. THE REMNANTS OF THIS
SYSTEM WILL LIKELY BE KEY TO WHERE THINGS FOCUS IN THE FORECAST AREA
TODAY. MODELS HAVE CONSISTENTLY SUGGESTED CAPE VALUES FROM 1500-2500
J/KG IN THE FORECAST AREA DURING PEAK HEATING TODAY, WHILE BULK
SHEAR VALUES SHOULD BE 35-45 KTS WEST AND 25-35 KTS EAST. THESE
PARAMETERS SUGGEST SOME STRONG TO SEVERE STORMS ARE POSSIBLE IN THE
AREA TODAY, BUT THE EXACT LOCATION/TIMING OF DEVELOPMENT WILL NOT BE
A HIGH CONFIDENCE FORECAST UNTIL WE SEE HOW THINGS PLAY OUT WITH THE
REMNANTS MOVING INTO OUR AREA.

&&

.LONG TERM...(TONIGHT THROUGH SATURDAY)
ISSUED AT 335 AM CDT SUN MAY 17 2015

00Z FORECAST MODELS TAKE 558 DM 500 MB LOW OVER CENTRAL NEBRASKA NE
INTO NORTHERN MN BY 12Z/MON WHILE 992 MB SURFACE LOW PRESSURE OVER
CENTRAL SD WEAKENS AS IT TRACKS NE INTO NORTHERN MN BY DAWN MONDAY.
THIS WILL BRING AN OCCCLUDED FRONT EAST INTO CENTRAL IL NEAR I-55 BY
18Z/MON AND NEARING THE WABASH RIVER BY 00Z/TUE. HIGHEST CHANCES OF
SHOWERS AND THUNDERSTORMS WILL SHIFT INTO EASTERN IL TONIGHT AND
MONDAY. SPC HAS SLIGHT RISK OF SEVERE STORMS OVER ALL BY FAR SE IL
NEAR WABASH RIVER THIS AFTERNOON/EVENING WITH 15% RISK OF LARGE HAIL
AND DAMAGING WIND GUSTS AND 2-5% RISK OF TORNADOES AND HIGHEST RISK
(5%) OVER KNOX...STARK AND MARSHALL COUNTIES. SPC KEEPS MARGINAL
RISK OF SEVERE STORMS MONDAY EAST OF IL OVER CENTRAL AND EASTERN
INDIANA. MILD LOWS TONIGHT IN THE MID TO UPPER 60S WITH SSW BREEZES.
ANOTHER WARM DAY MONDAY WITH HIGHS IN THE UPPER 70S WEST OF THE IL
RIVER AND LOWER 80S EAST OF THE IL RIVER. SW WINDS TURN WEST AND NW
BEHIND COLD FRONT AND DEWPOINTS WILL BE DROPPING BEHIND THE FRONT
DURING THE DAY. THOUGH STAYING HUMID DURING THE DAY MONDAY OVER
SOUTHEAST IL WITH DEWPOINTS IN THE UPPER 60S TO NEAR 70F.

LINGERED JUST SLIGHT CHANCE OF SHOWERS AND POSSIBLE THUNDERSTORM IN
FAR SE IL NEAR WABASH RIVER MONDAY EVENING. OTHERWISE DRY AND COOLER
AS CANADIAN HIGH PRESSURE SETTLES INTO THE MIDWEST BY TUE WITH A
FAIR AMOUNT OF SUNSHINE OVER CENTRAL/SE IL TUE WITH NW WINDS. LOWS
MON NIGHT RANGE FROM MID 40S OVER IL RIVER VALLEY TO MID 50S BY
LAWRENCEVILLE. HIGHS TUE RANGE FROM LOWER 60S NORTH OF I-74 TO
AROUND 70F BY LAWRENCEVILLE. ANOTHER COOL NIGHT TUE NIGHT WITH LOWS
IN THE MID TO UPPER 40S.

EXTENDED MODELS CONTINUE TO SHOW A DISTURBANCE EJECTING FROM THE
TROF/CUTOFF LOW NEAR CA INTO THE CENTRAL PLAINS WED AND BRINGING
MAINLY LIGHT QPF INTO CENTRAL AND SW IL WED AND SHIFTING IT
SOUTHWARD WED NIGHT AND THU. HAVE INCREASE POPS BY WED AFTERNOON TO
LIKELY FROM JACKSONVILLE SW WHILE LOWER POPS IN NE CWA BY DANVILLE.
MORE CLOUDS WED AND RAIN CHANCES TO KEEP IT COOLER WITH HIGHS IN
UPPER 50S AND LOWER 60S CENTRAL IL AND MID 60S SOUTHEAST OF I-70.

ANOTHER CANADIAN HIGH PRESSURE SETTLES INTO THE MIDWEST THU
RETURNING DRY WEATHER AND TEMPS MODERATING DUE TO MORE SUNSHINE WITH
HIGHS IN THE UPPER 60S. SEASONABLE HIGHS REACH THE LOW TO MID 70S
FRIDAY. LOOKS LIKE AN INCREASING CHANCE OF SHOWERS AND THUNDERSTORMS
DURING THE MEMORIAL DAY WEEKEND ESPECIALLY FROM SAT NIGHT ON WITH
DISTURBANCE EJECTING OUT OF SW UPPER LEVEL FLOW AND INCREASING TEMPS
AND HUMIDITY WITH SOUTHERLY FLOW RETURNING.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1158 PM CDT SAT MAY 16 2015
NOT TOO MUCH OF A SHIFT. MVFR/IFR CIGS MOVING IN AND SPREADING
OVER CENTRAL IL. SOUTHERLY WINDS CONTINUE. SOME VIS REDUCTION
POSSIBLE WITH THE ENHANCED/TRAPPED LLVL MOISTURE. ISSUES FOR
TOMORROWS FORECAST REMAIN WITH MODELS CHALLENGED BY CONVECTION.
WITH TIMING ISSUES...VCTS STARTING ROUGHLY MIDDAY, THEN PULLING
BACK TO VCSH LATER IN THE EVENING AS THE MAJORITY OF THE PRECIP
STARTING TO LOOK RAGGED ON MODEL DEPICTIONS.


&&

.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...07/BAK
LONG TERM...07
AVIATION...HJS



AREA FORECAST DISCUSSION

NWS QUAD CITIES IA IL

 110 PM CDT SUN MAY 17 2015

.UPDATE...
ISSUED AT 1257 PM CDT SUN MAY 17 2015

SEVERE RISK WHILE NOT ZERO IS QUITE LOW AND ISOLATED REST OF
TODAY...MAINLY FOCUSING NEXT HOUR FAR EASTERN CWA. CWA LARGELY
RESIDES IN BETWEEN FOCUSING MECHANISMS WITH PRESSURE PERTURBATION
AND LOW LEVEL CONVERGENCE ABOUT TO EXIT THE FAR EASTERN CWA NEXT
HOUR OR SO TAKING ANY SEVERE POTENTIAL WITH IT. 18Z DVN RAOB SHOWS
COUPLE OF CAPPING INVERSIONS AROUND OR ABOVE 800 MB IN THE WAKE
WHICH IN ABSENCE OF FORCING LOOKS TO SUPPRESS ANY ADDITIONAL
DEVELOPMENT. EXCEPTION BEING NORTHWEST CWA WHICH COULD SEE SOME
ACTIVITY DEVELOP OR PROPAGATE INTO LATE THIS AFTERNOON AND EVENING
FROM CENTRAL/WESTERN IA ATTENDANT TO VORT MAX AND COLDER POCKET OF
AIR ROTATING IN ALOFT. STRONG SHEAR AND DRY AIR ALOFT MAY HARBOR
SOME POTENTIAL FOR GUSTY WINDS AND HAIL WITH ANY OF THIS ACTIVITY.

&&

.SYNOPSIS...
ISSUED AT 340 AM CDT SUN MAY 17 2015

SYNOPSIS...HUGE SQUALL LINE OF SEVERE STORMS AND EMBEDDED TORNADOES
EXTENDED ALL THE WAY FROM NORTHERN MO TO CENTRAL TX. HOWEVER...THE
FAR NORTHERN PORTION OF THE LINE APPROACHING NORTHEAST MO AND
SOUTHCENTRAL IA WAS RAPIDLY WEAKENING AS IT RUNS INTO MUCH MORE
STABLE AIR WITH MINIMAL CAPE. ALSO...IR SATELLITE SHOWS RAPIDLY
WARMING TOPS. MEANWHILE BACK AT THE RANCH...LOW STRATUS HAS FORMED
OVER MUCH OF THE CWA DUE TO CONTINUED MOISTURE TRANSPORT FROM THE
SOUTH. 3 AM TEMPERATURES RANGED FROM THE MID 60S TO AROUND 70 WITH
DEWPOINTS IN THE MID 60S.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 340 AM CDT SUN MAY 17 2015

FORECAST FOCUS ON SEVERE POTENTIAL AND COVERAGE OF THUNDERSTORMS.

TODAY...SPC HAS SHIFTED THE ENHANCED SEVERE RISK NORTH OF THE CWA
CLOSER TO THE STRONGEST SHEAR AND TRIPLE POINT OF THE OCCLUDING
CYCLONE WITH A SLIGHT RISK OVER ALL OF THE CWA. SPC HAS A 5%
PROBABILITY FOR TORNADOES IN NORTHEAST IA AND NORTHERN IL WITH A 15%
PROBABILITY OF WIND AND HAIL OVER THE ENTIRE CWA. THIS IS A LOW
CONFIDENCE FORECAST OF EXACTLY HOW THE CONVECTION WILL PLAY OUT AS
MODELS DIFFER GREATLY...RANGING FROM NUMEROUS TO ONLY ISOLATED
STORMS.

FIRST OF ALL IS THIS MORNING WITH THE RAPIDLY DECAYING SQUALL LINE
WHICH WILL BE MOVING INTO OUR WESTERN AND SOUTHERN CWA EARLY THIS
MORNING...SO WILL HAVE LIKELY POPS FOR THOSE AREAS. THE HRRR MODEL
TAKES THIS WEAK LINE OVER ALL OF EASTERN IA TO ABOUT THE MS RIVER
THEN FADES IT BY MID MORNING...SO WILL HAVE CHANCE POPS THE FARTHER
EAST YOU GO INTO THE CWA. THEN WE HAVE THE LOW STRATUS FOR MUCH OF
THE MORNING WITH THE AVIATION GFS-LAMP GUIDANCE INDICATING THIS TO
DISSIPATE BY LATE MORNING/EARLY AFTERNOON SIMILAR TO YESTERDAY.

THIS AFTERNOON...COVERAGE OF THUNDERSTORMS IS PROBLEMATIC AS MODELS
HAVE DIFFERING SOLUTIONS. MODELS STILL INDICATE STRONG DEEP LAYER
SHEAR WITH 0-6KM OF 40-45 KTS AIDED BY CYCLONICALLY CURVED JET FROM
MID MISSISSIPPI VALLEY INTO GREAT LAKES. TEMPERATURES IN THE LOWER
TO MID 80S AND DEWPTS IN THE MID TO UPPER 60S SHOULD YIELD MODERATE
INSTABILITY WITH MLCAPES OF 1000-2000 J/KG. THIS IS CERTAINLY
SUFFICIENT TO SUPPORT ALL MODES OF SEVERE WEATHER. HOWEVER...WITH
THE OCCLUDING CYCLONE WE ARE ALSO LOSING THE FORCING/LOW LEVEL
CONVERGENCE TO GET STORMS TO DEVELOP...EXCEPT IN OUR FAR EASTERN
COUNTIES EARLY THIS AFTERNOON. THIS WILL BE INTERESTING TO SEE HOW
THIS PLAYS OUT BUT FOR NOW WILL HAVE THE HIGHEST POPS IN THE EAST
AND ONLY SLIGHT POPS IN THE SW. MAXIMUM TEMPERATURES SHOULD GET INTO
THE LOWER TO MID 80S AT MOST LOCATIONS.

TONIGHT...I WILL MAINTAIN THE SMALL POPS FOR EARLY THIS EVENING
ALONG AND EAST OF THE MS RIVER BUT WE COULD JUST AS EASILY BE DRY.
OPERATIONAL MODELS INDICATE DRY SLOT TO SPREAD OVER ALL THE CWA AS
THE OCCLUDING CYCLONE TRACKS INTO THE MN ARROWHEAD. SKIES WILL BE
CLEARING OR CLEAR WITH COOLER AND DRIER AIR BEGINNING TO PUSH INTO
THE NW CWA OVERNIGHT. MINIMUM TEMPERATURES WILL RANGE FROM THE MID
50S NW TO THE LOWER TO MID 60S SE.

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 340 AM CDT SUN MAY 17 2015

COOL BUT NICE MID MAY WEATHER FOR THE UPCOMING WORK WEEK WITH SOME
LIGHT RAIN POSSIBLE WEDNESDAY.

LONG TERM FORECAST CONFIDENCE ASSESSMENT...GOOD OR ABOVE AVERAGE WITH
LITTLE SENSIBLE WEATHER ISSUES. MAIN ISSUE IS DIURNAL TEMPERATURE RANGES
WITH MOST DAYS SUGGESTION OF WIDER RANGES OF HI/LO BY A DEGREE OR SO
MOST LOCATIONS SUPPORTED.

OVERVIEW...INITIALIZATION AND VERIFICATION IS GOOD WITH SLIGHTLY TOO
MOIST BL ISSUES NOTED THAT ARE IMPACTING NORMAL MODEL FIELDS CURRENTLY
AS TOO WIDESPREAD EXCEPT FOR LINEAR FEATURES UNDERDONE. THIS WILL HAVE
NO IMPACT MONDAY ONWARD. RUN TO RUN VARIANCES SUGGEST LITTLE DIFFERENCES
EXCEPT TEMPERATURES BY A CATEGORY OR SO WITH A MEAN TAKEN FOR LATER
SHIFTS TO REASSESS AS AGAIN PROBABLE A DEGREE OR TWO TO COOL/MILD FOR
HIGHS/LOWS MOST DAYS.

MONDAY...STRONG CAA TO RESULT IN BREEZY WEATHER WITH MANY LOCATIONS
TO HAVE NEARLY STEADY TEMPERATURES WITH 15 TO 25+ MPH WITH SOME GUSTS
TO 30 MPH NORTH HALF OF FORECAST AREA. STRONG GRADIENT WITH LOWER 60S
FAR NW TO UPPER 70S FAR SE SECTIONS. MONDAY NIGHT...WINDS MAY BE UP
ENOUGH TO PRECLUDE FROST RISK WITH UPPER 30S NW TO MID 40S SOUTH SECTIONS.

TUESDAY...BELOW NORMAL TEMPERATURES BY 10 TO 15 DEGREES WITH CONTINUED
CAA WITH LOW LEVEL THERMAL FIELDS SUPPORTIVE OF NEAR 60F FAR NORTH TO
MIDDLE 60S SOUTH SECTIONS DESPITE NEARLY FULL TO FULL SUNSHINE.
TUESDAY NIGHT...LIGHT WINDS MAY ALLOW FOR BL DECOUPLING NORTH 1/2
AND PATCHY FROST RISK FOR LATER SHIFT TO RECONSIDER. LOCAL TECHNIQUES
DO SUGGEST WITH FAIR SKIES AND BL DECOUPLING SOME MID 30S POSSIBLE
ALONG AND NORTH OF HIGHWAY 30 CORRIDOR FAVORED LOW LYING LOCATIONS.

WEDNESDAY...INCREASING CLOUDS WITH RISK OF SPRINKLES MOSTLY CENTRAL
SECTIONS AND SOME LIGHT RAIN SOUTH 1/3 OF AREA. HIGHS SHOULD WITH CLOUDS
BE MOSTLY LOWER 60S WITH UPPER 50S POSSIBLE IN HEAVIEST CLOUDS AND
POSSIBLE LIGHT RAIN. WEDNESDAY NIGHT...ANY LIGHT PRECIPITATION SHOULD
END AROUND MIDNIGHT WITH CLEARING SKIES BY MORNING ALL BUT FAR SE
SECTIONS. MINS LOWER TO MIDDLE 40S ARE REASONABLE.

THURSDAY THROUGH SATURDAY...MORE NICE WEATHER WITH UPPER 60S MOST LOCATIONS
FOR HIGHS ON THURSDAY AND LOWER 70S A GOOD REFERENCE POINT FRIDAY/SATURDAY
WITH LOW DEWPOINTS. MINS 40S RISING INTO THE 50S SATURDAY AND SUNDAY
AM WITH PROBABLE MOST LOCATIONS MINS ARE 2 TO 3 PLUS DEGREES TOO MILD
FOR LATER SHIFTS TO CONSIDER.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1238 PM CDT SUN MAY 17 2015

GENERALLY VFR CONDITIONS EXPECTED THROUGH THE TAF CYCLE. LOW CONFIDENCE
ON ANY SHOWER OR STORM DEVELOPMENT THIS AFTERNOON AND EARLY
EVENING...WITH FAVORED AREAS MAINLY EAST OF TERMINALS AHEAD OF WEAK
PRESSURE PERTURBATION AND LOW LEVEL CONVERGENCE...AND ALSO WEST OF THE
TERMINALS WITH COLDER AIR ALOFT ROTATING AROUND NORTHERN PLAINS
UPPER LOW. GUSTY SOUTHERLY WINDS 15-30 KTS WILL DIMINISH TO AROUND 10 KTS
THIS EVENING AND VEER TO WESTERLY OVERNIGHT WITH COLD FRONTAL PASSAGE.
WINDS WITH MIXING TO BECOME GUSTY AGAIN ON MONDAY AT 15-30 KTS FROM THE
WEST/NORTHWEST.

&&

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&

$$

UPDATE...05
SYNOPSIS...HAASE
SHORT TERM...HAASE
LONG TERM...NICHOLS
AVIATION...05




AREA FORECAST DISCUSSION

NWS QUAD CITIES IA IL

 1247 PM CDT SUN MAY 17 2015

.UPDATE...
ISSUED AT 715 AM CDT SUN MAY 17 2015

ONLY A FEW SHOWERS WERE NOTED ON RADAR IN THE DVN CWA AND MOST OF
THOSE WERE OCCURING IN OUR FAR WESTERN COUNTIES. I HAVE REMOVED
THE MENTION OF THUNDER THROUGH THE MID MORNING HOURS AT LEAST.
OTHERWISE...EXTENSIVE CLOUD COVER WILL BE SEEN THIS MORNING. THE
LATEST MESO MODEL RUNS INDICATE MUCH OF THE CWA TO REMAIN DRY
TODAY SO CONFIDENCE REMAINS LOW WITH REGARD TO THE COVERAGE OF
CONVECTION.

&&

.SYNOPSIS...
ISSUED AT 340 AM CDT SUN MAY 17 2015

SYNOPSIS...HUGE SQUALL LINE OF SEVERE STORMS AND EMBEDDED TORNADOES
EXTENDED ALL THE WAY FROM NORTHERN MO TO CENTRAL TX. HOWEVER...THE
FAR NORTHERN PORTION OF THE LINE APPROACHING NORTHEAST MO AND
SOUTHCENTRAL IA WAS RAPIDLY WEAKENING AS IT RUNS INTO MUCH MORE
STABLE AIR WITH MINIMAL CAPE. ALSO...IR SATELLITE SHOWS RAPIDLY
WARMING TOPS. MEANWHILE BACK AT THE RANCH...LOW STRATUS HAS FORMED
OVER MUCH OF THE CWA DUE TO CONTINUED MOISTURE TRANSPORT FROM THE
SOUTH. 3 AM TEMPERATURES RANGED FROM THE MID 60S TO AROUND 70 WITH
DEWPOINTS IN THE MID 60S.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 340 AM CDT SUN MAY 17 2015

FORECAST FOCUS ON SEVERE POTENTIAL AND COVERAGE OF THUNDERSTORMS.

TODAY...SPC HAS SHIFTED THE ENHANCED SEVERE RISK NORTH OF THE CWA
CLOSER TO THE STRONGEST SHEAR AND TRIPLE POINT OF THE OCCLUDING
CYCLONE WITH A SLIGHT RISK OVER ALL OF THE CWA. SPC HAS A 5%
PROBABILITY FOR TORNADOES IN NORTHEAST IA AND NORTHERN IL WITH A 15%
PROBABILITY OF WIND AND HAIL OVER THE ENTIRE CWA. THIS IS A LOW
CONFIDENCE FORECAST OF EXACTLY HOW THE CONVECTION WILL PLAY OUT AS
MODELS DIFFER GREATLY...RANGING FROM NUMEROUS TO ONLY ISOLATED
STORMS.

FIRST OF ALL IS THIS MORNING WITH THE RAPIDLY DECAYING SQUALL LINE
WHICH WILL BE MOVING INTO OUR WESTERN AND SOUTHERN CWA EARLY THIS
MORNING...SO WILL HAVE LIKELY POPS FOR THOSE AREAS. THE HRRR MODEL
TAKES THIS WEAK LINE OVER ALL OF EASTERN IA TO ABOUT THE MS RIVER
THEN FADES IT BY MID MORNING...SO WILL HAVE CHANCE POPS THE FARTHER
EAST YOU GO INTO THE CWA. THEN WE HAVE THE LOW STRATUS FOR MUCH OF
THE MORNING WITH THE AVIATION GFS-LAMP GUIDANCE INDICATING THIS TO
DISSIPATE BY LATE MORNING/EARLY AFTERNOON SIMILAR TO YESTERDAY.

THIS AFTERNOON...COVERAGE OF THUNDERSTORMS IS PROBLEMATIC AS MODELS
HAVE DIFFERING SOLUTIONS. MODELS STILL INDICATE STRONG DEEP LAYER
SHEAR WITH 0-6KM OF 40-45 KTS AIDED BY CYCLONICALLY CURVED JET FROM
MID MISSISSIPPI VALLEY INTO GREAT LAKES. TEMPERATURES IN THE LOWER
TO MID 80S AND DEWPTS IN THE MID TO UPPER 60S SHOULD YIELD MODERATE
INSTABILITY WITH MLCAPES OF 1000-2000 J/KG. THIS IS CERTAINLY
SUFFICIENT TO SUPPORT ALL MODES OF SEVERE WEATHER. HOWEVER...WITH
THE OCCLUDING CYCLONE WE ARE ALSO LOSING THE FORCING/LOW LEVEL
CONVERGENCE TO GET STORMS TO DEVELOP...EXCEPT IN OUR FAR EASTERN
COUNTIES EARLY THIS AFTERNOON. THIS WILL BE INTERESTING TO SEE HOW
THIS PLAYS OUT BUT FOR NOW WILL HAVE THE HIGHEST POPS IN THE EAST
AND ONLY SLIGHT POPS IN THE SW. MAXIMUM TEMPERATURES SHOULD GET INTO
THE LOWER TO MID 80S AT MOST LOCATIONS.

TONIGHT...I WILL MAINTAIN THE SMALL POPS FOR EARLY THIS EVENING
ALONG AND EAST OF THE MS RIVER BUT WE COULD JUST AS EASILY BE DRY.
OPERATIONAL MODELS INDICATE DRY SLOT TO SPREAD OVER ALL THE CWA AS
THE OCCLUDING CYCLONE TRACKS INTO THE MN ARROWHEAD. SKIES WILL BE
CLEARING OR CLEAR WITH COOLER AND DRIER AIR BEGINNING TO PUSH INTO
THE NW CWA OVERNIGHT. MINIMUM TEMPERATURES WILL RANGE FROM THE MID
50S NW TO THE LOWER TO MID 60S SE.

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 340 AM CDT SUN MAY 17 2015

COOL BUT NICE MID MAY WEATHER FOR THE UPCOMING WORK WEEK WITH SOME
LIGHT RAIN POSSIBLE WEDNESDAY.

LONG TERM FORECAST CONFIDENCE ASSESSMENT...GOOD OR ABOVE AVERAGE WITH
LITTLE SENSIBLE WEATHER ISSUES. MAIN ISSUE IS DIURNAL TEMPERATURE RANGES
WITH MOST DAYS SUGGESTION OF WIDER RANGES OF HI/LO BY A DEGREE OR SO
MOST LOCATIONS SUPPORTED.

OVERVIEW...INITIALIZATION AND VERIFICATION IS GOOD WITH SLIGHTLY TOO
MOIST BL ISSUES NOTED THAT ARE IMPACTING NORMAL MODEL FIELDS CURRENTLY
AS TOO WIDESPREAD EXCEPT FOR LINEAR FEATURES UNDERDONE. THIS WILL HAVE
NO IMPACT MONDAY ONWARD. RUN TO RUN VARIANCES SUGGEST LITTLE DIFFERENCES
EXCEPT TEMPERATURES BY A CATEGORY OR SO WITH A MEAN TAKEN FOR LATER
SHIFTS TO REASSESS AS AGAIN PROBABLE A DEGREE OR TWO TO COOL/MILD FOR
HIGHS/LOWS MOST DAYS.

MONDAY...STRONG CAA TO RESULT IN BREEZY WEATHER WITH MANY LOCATIONS
TO HAVE NEARLY STEADY TEMPERATURES WITH 15 TO 25+ MPH WITH SOME GUSTS
TO 30 MPH NORTH HALF OF FORECAST AREA. STRONG GRADIENT WITH LOWER 60S
FAR NW TO UPPER 70S FAR SE SECTIONS. MONDAY NIGHT...WINDS MAY BE UP
ENOUGH TO PRECLUDE FROST RISK WITH UPPER 30S NW TO MID 40S SOUTH SECTIONS.

TUESDAY...BELOW NORMAL TEMPERATURES BY 10 TO 15 DEGREES WITH CONTINUED
CAA WITH LOW LEVEL THERMAL FIELDS SUPPORTIVE OF NEAR 60F FAR NORTH TO
MIDDLE 60S SOUTH SECTIONS DESPITE NEARLY FULL TO FULL SUNSHINE.
TUESDAY NIGHT...LIGHT WINDS MAY ALLOW FOR BL DECOUPLING NORTH 1/2
AND PATCHY FROST RISK FOR LATER SHIFT TO RECONSIDER. LOCAL TECHNIQUES
DO SUGGEST WITH FAIR SKIES AND BL DECOUPLING SOME MID 30S POSSIBLE
ALONG AND NORTH OF HIGHWAY 30 CORRIDOR FAVORED LOW LYING LOCATIONS.

WEDNESDAY...INCREASING CLOUDS WITH RISK OF SPRINKLES MOSTLY CENTRAL
SECTIONS AND SOME LIGHT RAIN SOUTH 1/3 OF AREA. HIGHS SHOULD WITH CLOUDS
BE MOSTLY LOWER 60S WITH UPPER 50S POSSIBLE IN HEAVIEST CLOUDS AND
POSSIBLE LIGHT RAIN. WEDNESDAY NIGHT...ANY LIGHT PRECIPITATION SHOULD
END AROUND MIDNIGHT WITH CLEARING SKIES BY MORNING ALL BUT FAR SE
SECTIONS. MINS LOWER TO MIDDLE 40S ARE REASONABLE.

THURSDAY THROUGH SATURDAY...MORE NICE WEATHER WITH UPPER 60S MOST LOCATIONS
FOR HIGHS ON THURSDAY AND LOWER 70S A GOOD REFERENCE POINT FRIDAY/SATURDAY
WITH LOW DEWPOINTS. MINS 40S RISING INTO THE 50S SATURDAY AND SUNDAY
AM WITH PROBABLE MOST LOCATIONS MINS ARE 2 TO 3 PLUS DEGREES TOO MILD
FOR LATER SHIFTS TO CONSIDER.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1238 PM CDT SUN MAY 17 2015

GENERALLY VFR CONDITIONS EXPECTED THROUGH THE TAF CYCLE. LOW CONFIDENCE
ON ANY SHOWER OR STORM DEVELOPMENT THIS AFTERNOON AND EARLY
EVENING...WITH FAVORED AREAS MAINLY EAST OF TERMINALS AHEAD OF WEAK
PRESSURE PERTURBATION AND LOW LEVEL CONVERGENCE...AND ALSO WEST OF THE
TERMINALS WITH COLDER AIR ALOFT ROTATING AROUND NORTHERN PLAINS
UPPER LOW. GUSTY SOUTHERLY WINDS 15-30 KTS WILL DIMINISH TO AROUND 10 KTS
THIS EVENING AND VEER TO WESTERLY OVERNIGHT WITH COLD FRONTAL PASSAGE.
WINDS WITH MIXING TO BECOME GUSTY AGAIN ON MONDAY AT 15-30 KTS FROM THE
WEST/NORTHWEST.

&&

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&

$$

UPDATE...HAASE
SYNOPSIS...HAASE
SHORT TERM...HAASE
LONG TERM...NICHOLS
AVIATION...05



AREA FORECAST DISCUSSION

NWS QUAD CITIES IA IL

 716 AM CDT SUN MAY 17 2015

.UPDATE...
ISSUED AT 715 AM CDT SUN MAY 17 2015

ONLY A FEW SHOWERS WERE NOTED ON RADAR IN THE DVN CWA AND MOST OF
THOSE WERE OCCURING IN OUR FAR WESTERN COUNTIES. I HAVE REMOVED
THE MENTION OF THUNDER THROUGH THE MID MORNING HOURS AT LEAST.
OTHERWISE...EXTENSIVE CLOUD COVER WILL BE SEEN THIS MORNING. THE
LATEST MESO MODEL RUNS INDICATE MUCH OF THE CWA TO REMAIN DRY
TODAY SO CONFIDENCE REMAINS LOW WITH REGARD TO THE COVERAGE OF
CONVECTION.

&&

.SYNOPSIS...
ISSUED AT 340 AM CDT SUN MAY 17 2015

SYNOPSIS...HUGE SQUALL LINE OF SEVERE STORMS AND EMBEDDED TORNADOES
EXTENDED ALL THE WAY FROM NORTHERN MO TO CENTRAL TX. HOWEVER...THE
FAR NORTHERN PORTION OF THE LINE APPROACHING NORTHEAST MO AND
SOUTHCENTRAL IA WAS RAPIDLY WEAKENING AS IT RUNS INTO MUCH MORE
STABLE AIR WITH MINIMAL CAPE. ALSO...IR SATELLITE SHOWS RAPIDLY
WARMING TOPS. MEANWHILE BACK AT THE RANCH...LOW STRATUS HAS FORMED
OVER MUCH OF THE CWA DUE TO CONTINUED MOISTURE TRANSPORT FROM THE
SOUTH. 3 AM TEMPERATURES RANGED FROM THE MID 60S TO AROUND 70 WITH
DEWPOINTS IN THE MID 60S.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 340 AM CDT SUN MAY 17 2015

FORECAST FOCUS ON SEVERE POTENTIAL AND COVERAGE OF THUNDERSTORMS.

TODAY...SPC HAS SHIFTED THE ENHANCED SEVERE RISK NORTH OF THE CWA
CLOSER TO THE STRONGEST SHEAR AND TRIPLE POINT OF THE OCCLUDING
CYCLONE WITH A SLIGHT RISK OVER ALL OF THE CWA. SPC HAS A 5%
PROBABILITY FOR TORNADOES IN NORTHEAST IA AND NORTHERN IL WITH A 15%
PROBABILITY OF WIND AND HAIL OVER THE ENTIRE CWA. THIS IS A LOW
CONFIDENCE FORECAST OF EXACTLY HOW THE CONVECTION WILL PLAY OUT AS
MODELS DIFFER GREATLY...RANGING FROM NUMEROUS TO ONLY ISOLATED
STORMS.

FIRST OF ALL IS THIS MORNING WITH THE RAPIDLY DECAYING SQUALL LINE
WHICH WILL BE MOVING INTO OUR WESTERN AND SOUTHERN CWA EARLY THIS
MORNING...SO WILL HAVE LIKELY POPS FOR THOSE AREAS. THE HRRR MODEL
TAKES THIS WEAK LINE OVER ALL OF EASTERN IA TO ABOUT THE MS RIVER
THEN FADES IT BY MID MORNING...SO WILL HAVE CHANCE POPS THE FARTHER
EAST YOU GO INTO THE CWA. THEN WE HAVE THE LOW STRATUS FOR MUCH OF
THE MORNING WITH THE AVIATION GFS-LAMP GUIDANCE INDICATING THIS TO
DISSIPATE BY LATE MORNING/EARLY AFTERNOON SIMILAR TO YESTERDAY.

THIS AFTERNOON...COVERAGE OF THUNDERSTORMS IS PROBLEMATIC AS MODELS
HAVE DIFFERING SOLUTIONS. MODELS STILL INDICATE STRONG DEEP LAYER
SHEAR WITH 0-6KM OF 40-45 KTS AIDED BY CYCLONICALLY CURVED JET FROM
MID MISSISSIPPI VALLEY INTO GREAT LAKES. TEMPERATURES IN THE LOWER
TO MID 80S AND DEWPTS IN THE MID TO UPPER 60S SHOULD YIELD MODERATE
INSTABILITY WITH MLCAPES OF 1000-2000 J/KG. THIS IS CERTAINLY
SUFFICIENT TO SUPPORT ALL MODES OF SEVERE WEATHER. HOWEVER...WITH
THE OCCLUDING CYCLONE WE ARE ALSO LOSING THE FORCING/LOW LEVEL
CONVERGENCE TO GET STORMS TO DEVELOP...EXCEPT IN OUR FAR EASTERN
COUNTIES EARLY THIS AFTERNOON. THIS WILL BE INTERESTING TO SEE HOW
THIS PLAYS OUT BUT FOR NOW WILL HAVE THE HIGHEST POPS IN THE EAST
AND ONLY SLIGHT POPS IN THE SW. MAXIMUM TEMPERATURES SHOULD GET INTO
THE LOWER TO MID 80S AT MOST LOCATIONS.

TONIGHT...I WILL MAINTAIN THE SMALL POPS FOR EARLY THIS EVENING
ALONG AND EAST OF THE MS RIVER BUT WE COULD JUST AS EASILY BE DRY.
OPERATIONAL MODELS INDICATE DRY SLOT TO SPREAD OVER ALL THE CWA AS
THE OCCLUDING CYCLONE TRACKS INTO THE MN ARROWHEAD. SKIES WILL BE
CLEARING OR CLEAR WITH COOLER AND DRIER AIR BEGINNING TO PUSH INTO
THE NW CWA OVERNIGHT. MINIMUM TEMPERATURES WILL RANGE FROM THE MID
50S NW TO THE LOWER TO MID 60S SE.

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 340 AM CDT SUN MAY 17 2015

COOL BUT NICE MID MAY WEATHER FOR THE UPCOMING WORK WEEK WITH SOME
LIGHT RAIN POSSIBLE WEDNESDAY.

LONG TERM FORECAST CONFIDENCE ASSESSMENT...GOOD OR ABOVE AVERAGE WITH
LITTLE SENSIBLE WEATHER ISSUES. MAIN ISSUE IS DIURNAL TEMPERATURE RANGES
WITH MOST DAYS SUGGESTION OF WIDER RANGES OF HI/LO BY A DEGREE OR SO
MOST LOCATIONS SUPPORTED.

OVERVIEW...INITIALIZATION AND VERIFICATION IS GOOD WITH SLIGHTLY TOO
MOIST BL ISSUES NOTED THAT ARE IMPACTING NORMAL MODEL FIELDS CURRENTLY
AS TOO WIDESPREAD EXCEPT FOR LINEAR FEATURES UNDERDONE. THIS WILL HAVE
NO IMPACT MONDAY ONWARD. RUN TO RUN VARIANCES SUGGEST LITTLE DIFFERENCES
EXCEPT TEMPERATURES BY A CATEGORY OR SO WITH A MEAN TAKEN FOR LATER
SHIFTS TO REASSESS AS AGAIN PROBABLE A DEGREE OR TWO TO COOL/MILD FOR
HIGHS/LOWS MOST DAYS.

MONDAY...STRONG CAA TO RESULT IN BREEZY WEATHER WITH MANY LOCATIONS
TO HAVE NEARLY STEADY TEMPERATURES WITH 15 TO 25+ MPH WITH SOME GUSTS
TO 30 MPH NORTH HALF OF FORECAST AREA. STRONG GRADIENT WITH LOWER 60S
FAR NW TO UPPER 70S FAR SE SECTIONS. MONDAY NIGHT...WINDS MAY BE UP
ENOUGH TO PRECLUDE FROST RISK WITH UPPER 30S NW TO MID 40S SOUTH SECTIONS.

TUESDAY...BELOW NORMAL TEMPERATURES BY 10 TO 15 DEGREES WITH CONTINUED
CAA WITH LOW LEVEL THERMAL FIELDS SUPPORTIVE OF NEAR 60F FAR NORTH TO
MIDDLE 60S SOUTH SECTIONS DESPITE NEARLY FULL TO FULL SUNSHINE.
TUESDAY NIGHT...LIGHT WINDS MAY ALLOW FOR BL DECOUPLING NORTH 1/2
AND PATCHY FROST RISK FOR LATER SHIFT TO RECONSIDER. LOCAL TECHNIQUES
DO SUGGEST WITH FAIR SKIES AND BL DECOUPLING SOME MID 30S POSSIBLE
ALONG AND NORTH OF HIGHWAY 30 CORRIDOR FAVORED LOW LYING LOCATIONS.

WEDNESDAY...INCREASING CLOUDS WITH RISK OF SPRINKLES MOSTLY CENTRAL
SECTIONS AND SOME LIGHT RAIN SOUTH 1/3 OF AREA. HIGHS SHOULD WITH CLOUDS
BE MOSTLY LOWER 60S WITH UPPER 50S POSSIBLE IN HEAVIEST CLOUDS AND
POSSIBLE LIGHT RAIN. WEDNESDAY NIGHT...ANY LIGHT PRECIPITATION SHOULD
END AROUND MIDNIGHT WITH CLEARING SKIES BY MORNING ALL BUT FAR SE
SECTIONS. MINS LOWER TO MIDDLE 40S ARE REASONABLE.

THURSDAY THROUGH SATURDAY...MORE NICE WEATHER WITH UPPER 60S MOST LOCATIONS
FOR HIGHS ON THURSDAY AND LOWER 70S A GOOD REFERENCE POINT FRIDAY/SATURDAY
WITH LOW DEWPOINTS. MINS 40S RISING INTO THE 50S SATURDAY AND SUNDAY
AM WITH PROBABLE MOST LOCATIONS MINS ARE 2 TO 3 PLUS DEGREES TOO MILD
FOR LATER SHIFTS TO CONSIDER.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 715 AM CDT SUN MAY 17 2015

OCNL MVFR CIGS THIS MORNING THEN VFR CONDS THIS AFTERNOON AND
TONIGHT AS A COLD FRONT SWEEPS ACROSS THE AREA. LOW CONFIDENCE IN
COVERAGE OF THUNDERSTORMS WITH THE CURRENT THINKING ISOLATED TO
SCATTERED STORMS TO DEVELOP THIS AFTERNOON...MAINLY IN NORTHEAST
IOWA AND NORTHWEST ILLINOIS. SOUTH WINDS SUSTAINED 15 TO 20 KNOTS
WITH GUSTS TO 25 KNOTS TODAY...THEN SOUTHWEST AROUND 10 KNOTS
TONIGHT.

&&

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&

$$

UPDATE...HAASE
SYNOPSIS...HAASE
SHORT TERM...HAASE
LONG TERM...NICHOLS
AVIATION...HAASE




AREA FORECAST DISCUSSION

NWS QUAD CITIES IA IL

 343 AM CDT SUN MAY 17 2015

.SYNOPSIS...
ISSUED AT 340 AM CDT SUN MAY 17 2015

SYNOPSIS...HUGE SQUALL LINE OF SEVERE STORMS AND EMBEDDED TORNADOES
EXTENDED ALL THE WAY FROM NORTHERN MO TO CENTRAL TX. HOWEVER...THE
FAR NORTHERN PORTION OF THE LINE APPROACHING NORTHEAST MO AND
SOUTHCENTRAL IA WAS RAPIDLY WEAKENING AS IT RUNS INTO MUCH MORE
STABLE AIR WITH MINIMAL CAPE. ALSO...IR SATELLITE SHOWS RAPIDLY
WARMING TOPS. MEANWHILE BACK AT THE RANCH...LOW STRATUS HAS FORMED
OVER MUCH OF THE CWA DUE TO CONTINUED MOISTURE TRANSPORT FROM THE
SOUTH. 3 AM TEMPERATURES RANGED FROM THE MID 60S TO AROUND 70 WITH
DEWPOINTS IN THE MID 60S.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 340 AM CDT SUN MAY 17 2015

FORECAST FOCUS ON SEVERE POTENTIAL AND COVERAGE OF THUNDERSTORMS.

TODAY...SPC HAS SHIFTED THE ENHANCED SEVERE RISK NORTH OF THE CWA
CLOSER TO THE STRONGEST SHEAR AND TRIPLE POINT OF THE OCCLUDING
CYCLONE WITH A SLIGHT RISK OVER ALL OF THE CWA. SPC HAS A 5%
PROBABILITY FOR TORNADOES IN NORTHEAST IA AND NORTHERN IL WITH A 15%
PROBABILITY OF WIND AND HAIL OVER THE ENTIRE CWA. THIS IS A LOW
CONFIDENCE FORECAST OF EXACTLY HOW THE CONVECTION WILL PLAY OUT AS
MODELS DIFFER GREATLY...RANGING FROM NUMEROUS TO ONLY ISOLATED
STORMS.

FIRST OF ALL IS THIS MORNING WITH THE RAPIDLY DECAYING SQUALL LINE
WHICH WILL BE MOVING INTO OUR WESTERN AND SOUTHERN CWA EARLY THIS
MORNING...SO WILL HAVE LIKELY POPS FOR THOSE AREAS. THE HRRR MODEL
TAKES THIS WEAK LINE OVER ALL OF EASTERN IA TO ABOUT THE MS RIVER
THEN FADES IT BY MID MORNING...SO WILL HAVE CHANCE POPS THE FARTHER
EAST YOU GO INTO THE CWA. THEN WE HAVE THE LOW STRATUS FOR MUCH OF
THE MORNING WITH THE AVIATION GFS-LAMP GUIDANCE INDICATING THIS TO
DISSIPATE BY LATE MORNING/EARLY AFTERNOON SIMILAR TO YESTERDAY.

THIS AFTERNOON...COVERAGE OF THUNDERSTORMS IS PROBLEMATIC AS MODELS
HAVE DIFFERING SOLUTIONS. MODELS STILL INDICATE STRONG DEEP LAYER
SHEAR WITH 0-6KM OF 40-45 KTS AIDED BY CYCLONICALLY CURVED JET FROM
MID MISSISSIPPI VALLEY INTO GREAT LAKES. TEMPERATURES IN THE LOWER
TO MID 80S AND DEWPTS IN THE MID TO UPPER 60S SHOULD YIELD MODERATE
INSTABILITY WITH MLCAPES OF 1000-2000 J/KG. THIS IS CERTAINLY
SUFFICIENT TO SUPPORT ALL MODES OF SEVERE WEATHER. HOWEVER...WITH
THE OCCLUDING CYCLONE WE ARE ALSO LOSING THE FORCING/LOW LEVEL
CONVERGENCE TO GET STORMS TO DEVELOP...EXCEPT IN OUR FAR EASTERN
COUNTIES EARLY THIS AFTERNOON. THIS WILL BE INTERESTING TO SEE HOW
THIS PLAYS OUT BUT FOR NOW WILL HAVE THE HIGHEST POPS IN THE EAST
AND ONLY SLIGHT POPS IN THE SW. MAXIMUM TEMPERATURES SHOULD GET INTO
THE LOWER TO MID 80S AT MOST LOCATIONS.

TONIGHT...I WILL MAINTAIN THE SMALL POPS FOR EARLY THIS EVENING
ALONG AND EAST OF THE MS RIVER BUT WE COULD JUST AS EASILY BE DRY.
OPERATIONAL MODELS INDICATE DRY SLOT TO SPREAD OVER ALL THE CWA AS
THE OCCLUDING CYCLONE TRACKS INTO THE MN ARROWHEAD. SKIES WILL BE
CLEARING OR CLEAR WITH COOLER AND DRIER AIR BEGINNING TO PUSH INTO
THE NW CWA OVERNIGHT. MINIMUM TEMPERATURES WILL RANGE FROM THE MID
50S NW TO THE LOWER TO MID 60S SE.

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 340 AM CDT SUN MAY 17 2015

COOL BUT NICE MID MAY WEATHER FOR THE UPCOMING WORK WEEK WITH SOME
LIGHT RAIN POSSIBLE WEDNESDAY.

LONG TERM FORECAST CONFIDENCE ASSESSMENT...GOOD OR ABOVE AVERAGE WITH
LITTLE SENSIBLE WEATHER ISSUES. MAIN ISSUE IS DIURNAL TEMPERATURE RANGES
WITH MOST DAYS SUGGESTION OF WIDER RANGES OF HI/LO BY A DEGREE OR SO
MOST LOCATIONS SUPPORTED.

OVERVIEW...INITIALIZATION AND VERIFICATION IS GOOD WITH SLIGHTLY TOO
MOIST BL ISSUES NOTED THAT ARE IMPACTING NORMAL MODEL FIELDS CURRENTLY
AS TOO WIDESPREAD EXCEPT FOR LINEAR FEATURES UNDERDONE. THIS WILL HAVE
NO IMPACT MONDAY ONWARD. RUN TO RUN VARIANCES SUGGEST LITTLE DIFFERENCES
EXCEPT TEMPERATURES BY A CATEGORY OR SO WITH A MEAN TAKEN FOR LATER
SHIFTS TO REASSESS AS AGAIN PROBABLE A DEGREE OR TWO TO COOL/MILD FOR
HIGHS/LOWS MOST DAYS.

MONDAY...STRONG CAA TO RESULT IN BREEZY WEATHER WITH MANY LOCATIONS
TO HAVE NEARLY STEADY TEMPERATURES WITH 15 TO 25+ MPH WITH SOME GUSTS
TO 30 MPH NORTH HALF OF FORECAST AREA. STRONG GRADIENT WITH LOWER 60S
FAR NW TO UPPER 70S FAR SE SECTIONS. MONDAY NIGHT...WINDS MAY BE UP
ENOUGH TO PRECLUDE FROST RISK WITH UPPER 30S NW TO MID 40S SOUTH SECTIONS.

TUESDAY...BELOW NORMAL TEMPERATURES BY 10 TO 15 DEGREES WITH CONTINUED
CAA WITH LOW LEVEL THERMAL FIELDS SUPPORTIVE OF NEAR 60F FAR NORTH TO
MIDDLE 60S SOUTH SECTIONS DESPITE NEARLY FULL TO FULL SUNSHINE.
TUESDAY NIGHT...LIGHT WINDS MAY ALLOW FOR BL DECOUPLING NORTH 1/2
AND PATCHY FROST RISK FOR LATER SHIFT TO RECONSIDER. LOCAL TECHNIQUES
DO SUGGEST WITH FAIR SKIES AND BL DECOUPLING SOME MID 30S POSSIBLE
ALONG AND NORTH OF HIGHWAY 30 CORRIDOR FAVORED LOW LYING LOCATIONS.

WEDNESDAY...INCREASING CLOUDS WITH RISK OF SPRINKLES MOSTLY CENTRAL
SECTIONS AND SOME LIGHT RAIN SOUTH 1/3 OF AREA. HIGHS SHOULD WITH CLOUDS
BE MOSTLY LOWER 60S WITH UPPER 50S POSSIBLE IN HEAVIEST CLOUDS AND
POSSIBLE LIGHT RAIN. WEDNESDAY NIGHT...ANY LIGHT PRECIPITATION SHOULD
END AROUND MIDNIGHT WITH CLEARING SKIES BY MORNING ALL BUT FAR SE
SECTIONS. MINS LOWER TO MIDDLE 40S ARE REASONABLE.

THURSDAY THROUGH SATURDAY...MORE NICE WEATHER WITH UPPER 60S MOST LOCATIONS
FOR HIGHS ON THURSDAY AND LOWER 70S A GOOD REFERENCE POINT FRIDAY/SATURDAY
WITH LOW DEWPOINTS. MINS 40S RISING INTO THE 50S SATURDAY AND SUNDAY
AM WITH PROBABLE MOST LOCATIONS MINS ARE 2 TO 3 PLUS DEGREES TOO MILD
FOR LATER SHIFTS TO CONSIDER.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1153 PM CDT SAT MAY 16 2015

THE DISSIPATING REMNANTS FROM A LINE OF STRONG THUNDERSTORMS
ADVANCING FROM THE PLAINS WILL LIKELY MOVE INTO THE EASTERN IOWA
TERMINALS AS LIGHT RAIN WITH MVFR CONDITIONS DUE TO STRATUS AND
FOG TOWARD MORNING. BEYOND...THE FORECAST REMAINS LOW CONFIDENCE
WITH RESPECT TO THE POTENTIAL FOR STRONG TO SEVERE STORMS AS AN
UPPER LEVEL TROUGH MOVES THROUGH LATER IN THE DAY. FOR NOW...THIS
POTENTIAL IS LIMITED TO HIGHER CONFIDENCE CHANCE FOR SHOWERS IN
THE LATE MORNING OR EARLY AFTERNOON. GUSTY SOUTH WINDS WILL
GRADUALLY VEER TO MORE SOUTHWEST TOWARD SUNDAY EVENING WITH
PREVAILING VFR CONDITIONS.


&&

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.

&&

$$

SYNOPSIS...HAASE
SHORT TERM...HAASE
LONG TERM...NICHOLS
AVIATION...SHEETS




AREA FORECAST DISCUSSION

NWS DODGE CITY KS

 1202 AM CDT SUN MAY 17 2015

...UPDATE TO AVIATION...

.SYNOPSIS...
ISSUED AT 1035 PM CDT SAT MAY 16 2015

WV IMAGERY AND 00Z UPPER AIR ANALYSIS INDICATE AN UPPER LEVEL
TROUGH OF LOW PRESSURE LIFTING NORTHEAST ACROSS THE WESTERN HIGH
PLAINS. MEANWHILE, WEAK UPPER LEVEL RIDGING IS MOVING EASTWARD
ACROSS THE DESERT SOUTHWEST. NEAR THE SURFACE, A BROAD AREA OF LOW
PRESSURE EXTENDS FROM WESTERN NEBRASKA SOUTHWARD INTO EXTREME
EASTERN COLORADO.

&&

.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 128 PM CDT SAT MAY 16 2015

ABBREVIATED SHORT TERM WITH MET WATCH. MADE ADJUSTMENTS TO POPS
CONCERNING THE NON SEVERE THUNDERSTORMS ACROSS SOUTH-CENTRAL
KANSAS EARLY THIS AFTERNOON. SOME OF THE ACTIVITY ACROSS OKLAHOMA
HAS BEEN INCREASING IN INTENSITY, SO WILL HAVE TO WATCH OUT FOR
MARGINALLY SEVERE BASICALLY SE OF A LINE FROM ASHLAND TO ST JOHN.
THE NEXT AREA OF CONCERN IS OUT WEST. BUBBLING CUMULUS HAS BEEN
NOTED ON VIS SAT. TOOK A BLEND OF THE HRRR AND WRF-ARW FOR POP
ARRANGEMENTS WITH THIS ACTIVITY. WE LAUNCHED AN 18Z RAOB, WHICH
LOOKS FAR FROM SPECTACULAR. FIRST, INSTABILITY IS OBVIOUSLY VERY
LIMITED WITH ALL LINGERING CLOUD COVER. SECOND, 850-HPA WINDS ARE
VERY WEAK. IN FACT, THE ENTIRE LOW LEVELS ARE WEAK, ALTHOUGH
THERE IS DECENT VEERING. THIRDLY, UPPER LEVEL WINDS ARE BACKED.
TRANSLATION: MESSY HP SUPERCELLS. SO THE SITUATION HAS CHANGED A
BIT FROM PREVIOUSLY THOUGHT. THE MORNING SHOWERS AND THUNDERSTORMS
WILL PROBABLY HAVE DELETERIOUS IMPACTS TO STORM INTENSITY. RAP
ANALYSIS DOES SHOW CAPE INCREASING OUT WEST. STILL THINK WE WILL
STILL SEE SEVERE. THINK TORNADO POTENTIAL IS NOT AS HIGH AS
PREVIOUSLY THOUGH. THERE IS ENOUGH SHEAR TO GET ROTATING STORMS
THOUGH AND A FEW TORNADOES ARE NOT OUT OF THE QUESTION. WHAT IS
IN QUESTION IS IF THE TORNADOES WILL BE STRONG OR NOT. HAVE SEEN
AN UPTICK ON UPDRAFT HELICITY RECENTLY, SO SOMETHING TO MONITOR.
FROM THE 18Z RAOB, IT WILL TAKE QUITE THE ATMOSPHERIC TURN OVER
TO GET IT PRIMED FOR STRONG TORNADOES WITH DECENT INSTABILITY AND
STRENGTHENING LOW LEVEL WINDS. THERE IS SOME CONCERN ACROSS SOUTH-
CENTRAL KANSAS THAT LOW LEVEL WINDS THIS EVENING WILL STRENGTHEN
AND THE TORNADO POTENTIAL COULD GO UP. BUT BY THAT TIME, THE
STORMS COULD BE OUTFLOWY, PRECIPITATION LADEN MESSY STORMS. WILL
CONTINUE TO MONITOR THE MESOSCALE SITUATION AND ADJUST AS
NECESSARY. STORMS WILL BE MOVING AT A GOOD CLIP TOO.

.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 156 PM CDT SAT MAY 16 2015

THE SOUTHERN BRANCH OF THE WESTERLIES WILL CONTINUE TO BE ACTIVE
WITH AMPLIFICATION RESULTING FROM TROPICAL CONVECTION ACROSS THE
WESTERN PACIFIC. SUNDAY AND MONDAY WILL BE BETWEEN SYSTEMS AND THE
ONLY FORECAST CHALLENGE WILL BE TEMPERATURES AS ACTIVELY GROWING
VEGETATION AND WET SOILS WILL IMPACT TEMPERATURES.

THE NORTHERN BRANCH OF THE WESTERLIES WILL ALLOW SFC HIGH
PRESSURE TO BUILD INTO THE AREA MONDAY. WITH THE APPROACH OF
ANOTHER S/WV TROUGH IN THE SOUTHERN BRANCH, THE MOIST BOUNDARY
LAYER AIR SHOULD BE MOVING BACK NORTHWEST INTO THE HIGHER TERRAIN.
WIDESPREAD CONVECTION SHOULD RESULT BY TUESDAY AND INTO WEDNESDAY.
YET ANOTHER SYSTEM IS EXPECTED TOWARDS NEXT WEEKEND WITH
ADDITIONAL PCPN EXPECTED.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1200 AM CDT SUN MAY 17 2015

VFR CONDITIONS WILL PREVAIL AT ALL TAF SITES THROUGH LATE SUNDAY
AFTERNOON. LIGHT SOUTHERLY WINDS OVERNIGHT WILL BECOME MORE
SOUTHWEST TO WESTERLY EARLY SUNDAY MORNING AS A SURFACE LOW IN
EASTERN COLORADO LIFTS NORTHEAST INTO NEBRASKA.

&&

.PRELIMINARY POINT TEMPS/POPS...
DDC  50  70  47  63 /   0  10  20  60
GCK  48  69  46  62 /   0   0  20  60
EHA  48  69  48  62 /   0   0  40  70
LBL  51  73  49  64 /   0   0  30  70
HYS  49  67  44  62 /   0   0  10  40
P28  55  76  50  67 /   0  10  10  30

&&

.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...JJOHNSON
SHORT TERM...SUGDEN
LONG TERM...HUTTON
AVIATION...JJOHNSON



AREA FORECAST DISCUSSION

NWS JACKSON KY

 300 PM EDT SUN MAY 17 2015

.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 300 PM EDT SUN MAY 17 2015

THE HRRR MODEL HAS HAD THE BEST HANDLE ON THIS AFTERNOONS SHOWER
AND STORM ACTIVITY...WITH THE BULK OF CURRENT ACTIVITY OCCURRING
IN OUR FAR WESTERN COUNTIES. THE NAM12 HAS BEEN KEEPING CONVECTIVE
ACTIVITY MOST EXTENSIVE ACROSS OUR FAR EASTERN COUNTIES...WHICH IS
THE OPPOSITE OF WHAT IS ACTUALLY HAPPENING. THEREFORE...THE HRRR
SOLUTION WAS USED TO COMPOSE THE FIRST 12 HOURS OF THE SHORT TERM
FORECAST...AFTER 12Z...THE CONSALL SOLUTION WAS USED FOR THE
FORECAST. MORE SHOWERS AND STORMS WILL CONTINUE TO FORM WEST AND
SOUTHWEST OF THE AREA THROUGH THIS EVENING...AND THIS ACTIVITY
WILL SLOWLY MOVE WESTWARD INTO AND ACROSS EASTERN KENTUCKY THROUGH
0Z OR SO. AFTER THAT...ONCE THE SUN IS DOWN AND LOSS OF HEATING
OCCURS...THE SHOWERS AND STORMS WILL DROP OFF IN COVERAGE PRETTY
QUICKLY. AFTER HIGH RAIN CHANCES THIS AFTERNOON AND EVENING...THE
OVERNIGHT HOURS ARE FORECAST TO SEE ONLY ISOLATED SHOWERS AND
STORMS. SHOWERS AND STORMS WILL BE ON THE INCREASE AGAIN ON
MONDAY...BEGINNING IN THE LATE MORNING HOURS...AS A COLD FRONT
SLOWLY APPROACHES FROM THE WEST. THE PEAK OF ACTIVITY LOOKS TO BE
DURING THE AFTERNOON AND EVENING HOURS ONCE AGAIN...DURING PEAK
HEATING AND FRONTAL PASSAGE. SOME OF THE STRONGER STORMS COULD
PRODUCE LOCALLY HEAVY RAINFALL AND CLOUD TO GROUND LIGHTNING.

TEMPERATURES DURING THE SHORT TERM ARE STILL ON TRACK TO RUN WELL
ABOVE NORMAL FOR THIS TIME OF YEAR...REMAINING IN STEP WITH
CURRENT TRENDS AND A PERSISTENT SOUTHERLY FLOW PATTERN THAT HAS
BEEN CONSISTENTLY PUMPING WARM MOIST AIR OFF THE GULF OF MEXICO
INTO THE REGION. HIGHS ON MONDAY ARE STILL EXPECTED TO TOP OUT IN
THE LOWER 80S ACROSS THE AREA...WITH OVERNIGHT LOWS TONIGHT AND
TOMORROW NIGHT ONLY FALLING INTO THE LOW TO MID 60S.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 300 PM EDT SUN MAY 17 2015

MODELS APPEAR TO BE IN GOOD AGREEMENT WITH THE MID AND UPPER LEVEL
PATTERN OVER OUR REGION...BUT DIFFER MORE ON DETAILS OF SENSIBLE
WEATHER WITH A SHORTWAVE DISTURBANCE LATE WEDNESDAY OR WEDNESDAY
NIGHT INTO EARLY THURSDAY.

IN GENERAL ZONAL FLOW WILL DOMINATE THE PATTERN UNTIL THE LAST 48
HOURS OF THE EXTENDED WHERE SHORT WAVE RIDGING WILL BUILD INTO AND
ACROSS THE OHIO VALLEY IN RESPONSE TO EASTWARD MOVEMENT OF WEST
COAST CUT OFF LOW. AT THE SURFACE A COOL CANADIAN AIR MASS...HIGH
PRESSURE SYSTEM WILL SETTLE DOWN INTO THE HEART OF THE CONUS BEHIND
AN EXITING COLD FRONT...NOSING ITS WAY INTO THE OHIO VALLEY. AS A
RESULT WE CAN EXPECT DRY...PLEASANTLY COOL WEATHER FOR THE START OF
THE EXTENDED. ALOFT...THE AFOREMENTIONED DISTURBANCE WILL ROUND A
DEEP HUDSON BAY LOW WEDNESDAY NIGHT. WE APPEAR TO RECEIVE A GLANCING
BLOW FROM THIS FEATURE AS IT TRACKS THROUGH THE GREAT LAKES REGION.
A SECOND LESS IMPRESSIVE DISTURBANCE BRUSHES THE OHIO VALLEY BY LATE
IN THE WEEK...DY6 FRI.

THE MAIN FORECAST CHALLENGE IN THE EXTENDED WILL BE THE SHORT WAVE
DISTURBANCE MOVING THROUGH THE AREA WEDNESDAY NIGHT INTO EARLY
THURSDAY. THE 0Z AND 12Z ECMWF PRODUCE CONSIDERABLY MORE SENSIBLE
WEATHER WITH THIS FEATURE THAN EITHER THE 0Z OR 12Z GFS. NOT SEEING
MUCH IN THE WAY OF TRENDS TO HELP WITH PREFERENCE OF SOLUTIONS.
THEREFORE RELIED STRONGLY ON MODEL BLENDS CONSIDERING THE MURKY
DETAILS WITH SENSIBLE WEATHER. INCREASING HEIGHTS THROUGH THE END OF
THE EXTENDED WILL MEAN A GRADUAL RISE IN TEMPS...INTO THE 80S BY THE
END OF THE FORECAST WINDOW.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 127 PM EDT SUN MAY 17 2015

ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WILL MOVE ACROSS
EASTERN KENTUCKY TO BEGIN THE TAF PERIOD. BY 18 OR 19Z WE SHOULD
SEE MORE WIDESPREAD ACTIVITY...WITH EACH OF THE TAF SITES SEEING
THE POSSIBILITY OF SHOWERS AND STORMS THROUGH AROUND 23Z THIS
AFTERNOON. MVFR AND POSSIBLY IFR CONDITIONS WILL BE POSSIBLE
WHENEVER A SHOWER OR STORM DIRECTLY AFFECTS A TAF SITE. SCT TO BKN
CLOUD COVER WILL ALSO BE ON TAP THROUGHOUT THE PERIOD. SOME VALLEY
FOG WILL ALSO BE POSSIBLE BETWEEN 6 AND 13Z MONDAY...BUT NONE OF
THIS SHOULD AFFECT THE TAF SITES.


&&

.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...AR
LONG TERM...AR
AVIATION...AR



AREA FORECAST DISCUSSION

NWS PADUCAH KY

 1201 AM CDT SUN MAY 17 2015

.UPDATE...
ISSUED AT 1201 AM CDT SUN MAY 17 2015

THE AVIATION SECTION HAS BEEN UPDATED FOR THE 06Z TAF ISSUANCE.

&&

.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 208 PM CDT SAT MAY 16 2015

LOCALLY HEAVY RAIN IN PARTS OF WEST KY WITH AMOUNTS SINCE MIDNIGHT
1-2" IN A FEW SPOTS...MOSTLY AT OR BELOW 1". AREAL FLOOD
ADVISORIES WILL SUFFICE GIVEN THE PROGRESSIVE NATURE OF THE
ACTIVITY AND THE DOWNWARD TREND EXPECTED OVERALL. LITTLE TO NO
LIGHTNING...DEFINITELY EFFICIENT NONE THE LESS GIVEN WEAK LAPSE
RATES AND SMALL CAPE. ALL THE MODELS POINT TO A DIMINISHING TREND
FOR THE OVERNIGHT IN THE WAKE OF THIS WAVE THAT WE HAVE MONITORED
ON WVAPOR MOVING SLOWLY NE. THE RAP AND NAM WERE GENERALLY
FOLLOWED. WE CONTINUE TO HOLD TEMPS DOWN THE REST OF TODAY AS
WELL. THEY SHOULD FALL LITTLE TONIGHT WITH THE STAGNANT/HUMID
AIRMASS IN PLACE AND SOUTHERLY FLOW THE RULE.

SPC EXPANDED THEIR SLIGHT RISK AREA EAST DAY 2 INTO 1/2 OF THE
AREA FROM THE WEST. THIS SEEMS OVERDONE AND TEND TO DISAGREE. SURE
THERE COULD BE A FEW WARNINGS. BUT ENOUGH QUESTION MARKS EXIST.
THE NAM SUGGESTS A MIN CORRIDOR OF WEAK INSTABILITY ACROSS MUCH
OF THE AREA SUNDAY WITH CONVECTION AND CLOUDS ALREADY INTO THE
AREA AND BETTER DESTABILIZATION TO OUR WEST AND EAST. THE GFS AND
ECMWF SHOW BETTER DESTABILIZATION THROUGH THE DAY. EVEN IF WE
DESTABILIZE... BETTER WIND FIELDS ARE POSITIONED TO OUR WEST AND
NORTH AND NOT SUPPORTIVE OF SUSTAINED ORGANIZATION. WILL KEEP
POPS HIGH CHANCE GIVEN UNCERTAINTY WITH RESPECT TO COVERAGE.
SHOULD BE WARMER THAN TODAY.

SUNDAY NIGHT THROUGH MONDAY EVENING...WILL CONTINUE WITH HIGH
CHANCE TO LOW END LIKELY POPS FOR CONVECTION...AS THE FRONT VERY
SLOWLY WORKS SOUTH INTO THE AREA BY MONDAY EVENING/NIGHT. BEST
CHANCES WILL EVENTUALLY FOCUS ACROSS THE SOUTHEAST 1/2 TO 2/3 OF
THE AREA.

.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 208 PM CDT SAT MAY 16 2015

HIGHER THAN AVERAGE CONFIDENCE IN THE EXTENDED.

MODELS AND ENSEMBLES IN FAIR AGREEMENT WITH THE EXTENDED FORECAST.
SURFACE HIGH PRESSURE WILL BE THE MAIN SYNOPTIC SCALE FEATURE IN
CONTROL. HOWEVER THERE WILL BE A WEAK PERTURBATION IN THE NEARLY
ZONAL FLOW ALOFT WITH A REFLECTION OF A SURFACE LOW PASSING JUST TO
OUR SOUTH. THIS WILL BRING AT LEAST A CHANCE OF SHOWERS TO THE AREA
WEDNESDAY. SURFACE BASED CONVECTION LOOKS UNLIKELY WITH POSITIVE
LI`S AND LITTLE TO NO CAPE. ALTHOUGH SHOWALTERS IN VERY POSITIVE...K
INDEX VALUES ARE IN THE MID 20S. SO WILL NOT RULE OUT A CLAP OF
THUNDER BUT NOTHING IMPRESSIVE AT THIS TIME. OTHERWISE HIGH PRESSURE
WILL BE THE DOMINANT FEATURE AFTER THE PASSAGE OF THIS SURFACE LOW.

TEMPERATURES WILL BE AT SLIGHTLY BELOW NORMAL IN THE EXTENDED WITH
WINDS RELATIVELY LIGHT AFTER WEDNESDAY.

&&

.AVIATION...
ISSUED AT 1201 AM CDT SUN MAY 17 2015

AREA OF MVFR CEILINGS IS SPREADING EASTWARD TOWARD KCGI AT THIS
TIME...AND FIGURE THAT TREND WILL CONTINUE THROUGH THE OVERNIGHT
HOURS. 50KTS OF SSW WINDS AT 925MB ON THE KPAH 88-D VWP CERTAINLY
IS WORTHY OF A MENTION OF LLWS OVERNIGHT. THINK THERE WILL BE
GUSTS AT KCGI...SO DID NOT INCLUDE IT THERE.

CONVECTION MOVING EAST OUT OF THE PLAINS SHOULD STRUGGLE TO MAKE
IT THIS FAR EAST OVERNIGHT. STILL PLANNING ON A DIURNAL CONVECTIVE
SIGNAL THAT MAY BE ENHANCED BY TAIL END OF PLAINS UPPER SYSTEM AND
POTENTIAL OUTFLOW BOUNDARY FROM TONIGHTS PLAINS CONVECTION. PUSHED
IT BACK AN HOUR OR TWO...ESPECIALLY AT KEVV AND KOWB.

SOUTH SOUTHWEST WINDS WILL INCREASE SIGNIFICANTLY WITH MIXING
LATE MORNING. SOME GUSTS 20-25KT CAN BE EXPECTED.

&&

.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&

$$

UPDATE...DRS
AVIATION...DRS




AREA FORECAST DISCUSSION

NWS SHREVEPORT LA

 455 PM CDT SUN MAY 17 2015

.DISCUSSION...
MOST OF THE REMNANTS OF THE MORNING MCS HAVE EXITED THE REGION AS
OF 2115Z...ALTHOUGH SCT CONVECTION HAS REDEVELOPED OVER SE TX/SW
LA AND HAVE BEGUN TO SPREAD NE INTO THE HIGHER INSTABILITY AIR
WHERE MLCAPES STILL RANGE FROM 2000-2500 J/KG. BELIEVE THAT MUCH
OF THIS CONVECTION WILL GRADUALLY DIMINISH BY EARLY/MID EVENING
WITH THE LOSS OF HEATING/STABILITY. HOWEVER...OUR FOCUS WILL TURN
TO THE W AS THE AFTERNOON WATER VAPOR IMAGERY DEPICTS A WELL-
DEFINED SHORTWAVE OVER ERN NM ENTERING FAR W TX...WHICH REMAINS
PROGGED TO LIFT NE ACROSS THE RED RIVER VALLEY LATE THIS
EVENING/OVERNIGHT. THE AIR MASS OVER E TX/SE OK/SW AR REMAINS
SOMEWHAT STABLE THIS AFTERNOON IN WAKE OF THE MORNING
MCS...ALTHOUGH SBCIN HAS WEAKENED OVER THIS AREA OVER THE LAST FEW
HOURS AS SOME HEATING HAS OCCURRED BENEATH THE DENSE CONVECTIVE
DEBRIS IN PLACE. THE SHORT TERM PROGS ARE IN GENERAL AGREEMENT
WITH SCT CONVECTION REDEVELOPING LATER THIS EVENING OVER THE
REGION...ATOP A STILL MOIST AND SOMEWHAT UNSTABLE AIRMASS WHERE
DIFFLUENT FLOW ALOFT SPREADS OVER THE REGION. COULD ALREADY BE
SEEING EVIDENCE OF THE FORCING ALOFT OVER SCNTRL/WCNTRL TX...WHERE
VISIBLE SATELLITE IMAGERY DEPICTS AN ELEVATED CU/AC FIELD
DEVELOPING OVER THESE AREAS. THE NAM/GFS ARE A LITTLE MORE
AGGRESSIVE IN DEVELOPING SCT CONVECTION BY MID TO LATE
EVENING...WITH THE HRRR A BIT SLOWER /AFTER 06Z/ OVER NE TX/SW
AR/POSSIBLY NW LA. HOWEVER...QPF PLACEMENTS VARY CONSIDERABLE WITH
THE MODELS THIS AFTERNOON...AND HAVE TAKEN A BLEND OF THE MODELS
AND ISSUED A FLASH FLOOD WATCH FROM 03Z THIS EVENING THROUGH 18Z
MONDAY FOR MUCH OF E TX/SE OK/SW AR/NW LA. THESE AREAS REMAIN
SATURATED FROM HEAVY RAINFALL THAT HAS FALLEN OVER THE LAST COUPLE
OF WEEKS...AND WILL BE FAIR GAME FOR CELL TRAINING LATER TONIGHT.

HAVE ADDED HEAVY RAINFALL TO THE FORECAST LATE TONIGHT THROUGH
MONDAY MORNING FOR THE WATCH AREA...AS PW/S CLIMB TO 1.8-2.0
INCHES...VERY NEAR THE MAX MOVING AVERAGE OF CLIMO FOR THE DATE.
AREAS TO THE SE OVER THE SRN SECTIONS OF NCNTRL LA HAVE NOT SEEN
NEARLY AS MUCH RAIN AS AREAS FARTHER N AND W...AND SHOULD BE ABLE
TO TAKE THE HEAVY RAIN AS IT MOVES THROUGH THE AREAS MONDAY. THE
HEAVY RAINFALL/FLASH FLOOD THREAT OVER THE WATCH AREAS SHOULD
DIMINISH BY EARLY MONDAY AFTERNOON AS THE SHORTWAVE QUICKLY
SPREADS ENE INTO THE MID-SOUTH/LOWER MS VALLEY.

THE CLOSED LOW A CPL HUNDRED MILES W OF THE CA COAST THIS
AFTERNOON IS EXPECTED TO COME ASHORE INTO CA EARLY MONDAY...WITH
THE MAIN ATTENDENT TROUGH LIFTING NE INTO THE SRN ROCKIES BY EARLY
TUESDAY AND INTO THE PLAINS TUESDAY AFTERNOON. THIS TROUGH WILL
HELP TO AMPLIFY SOMEWHAT FLAT UPPER RIDGING ALOFT OVER THE SRN
PLAINS/MID AND LOWER MS VALLEY AND SE STATES TUESDAY...WITH THE
FLAT RIDGING PERSISTING THROUGH MUCH OF THIS WEEK. THE SHORT TERM
PROGS REMAIN IN AGREEMENT WITH A WEAK SFC FRONT BACKDOORING SW
INTO ERN OK/CNTRL AR TUESDAY MORNING BEFORE BECOMING STATIONARY.
PREFER THE NAM/ECMWF POSITION OF THE FRONT THAN THE GFS...WHICH
SEEMS MUCH TOO FAR S GIVEN THE LACK OF HEIGHT FALLS ALOFT TO HELP
DRIVE THE FRONT FARTHER S. THE FRONT SHOULD HELP FOCUS SCT
CONVECTION DURING PEAK HEATING TUESDAY...WHILE OTHER ISOLATED TO
WIDELY SCT CONVECTION DEVELOPS FARTHER S WHERE
INSTABILITY/MOISTURE LIE OVER E TX/N LA...EVEN A WEAK
PERTURBATIONS SHIFT E ATOP THE FLAT RIDGE ALOFT. THE SFC FRONT
SHOULD LIFT BACK N TUESDAY NIGHT...BEFORE ANOTHER WEAK COOL FRONT
BEGINS TO BUILD S ACROSS OK/NW AR WEDNESDAY AFTERNOON. THE PROGS
ARE AGAIN KEYING IN WEAKNESSES IN THE FLOW ALOFT ATOP THE RIDGE TO
ENHANCE SCT CONVECTION DEVELOPMENT MAINLY OVER CNTRL/SRN OK/SW AR
WEDNESDAY AFTERNOON...BEFORE THE FRONT SLOWLY SLIDE INTO THE
REGION WEDNESDAY NIGHT/THURSDAY BEFORE BECOMING STATIONARY.

HAVE MAINTAINED LIKELY/HIGH CHANCE POPS WEDNESDAY NIGHT AHEAD OF
THE FRONT...WITH MID CHANCE POPS THURSDAY WITH THE FROPA. HAVING
THE SFC BNDRY AROUND THROUGH LATE FRIDAY WILL FOCUS SCT CONVECTION
DEVELOPMENT THROUGH LATE WEEK...BEFORE THE FRONT BEGINS TO LIFT
BACK N OUT OF THE AREA. TEMPS WILL REMAIN NEAR/SLIGHTLY ABOVE
CLIMO THROUGH MUCH OF THE PERIOD.

PRELIMS TO FOLLOW BELOW...

15

&&

.PREV DISCUSSION... /ISSUED 101 PM CDT SUN MAY 17 2015/

AVIATION...
BAND OF CONVECTION THIS MORNING MOVG ACROSS AREA FROM THE
WEST...HAS BECOME SCATTERED IN VCNTY OF KLFK...KSHV...KMLU...AND
KELD...AND HAS JUST MOVD EAST OF KTXK...KGGG...AND KTYR. BRIEF IFR
VSBYS MAY OCCUR IN VERY HEAVY RAIN...OTHERWISE...EXPECT VFR
CONDITIONS THRU AT LEAST 18/04Z. AIRMASS LIKELY TOO STABLE THIS
AFTN IN WAKE OF THIS CONVECTION FOR REDEVELOPMENT WITH AFTN
HEATING. NEXT CONVECTIVE BAND PROGGED TO ENTER CWA LATE THIS EVE
ACROSS NE TX...BECMG MORE WIDESPREAD LATER TONIGHT AS IT MOVES
ACROSS LA/AR PORTIONS OF AREA. LIGHT TO SOUTHERLY WINDS AROUND 10
KTS CAN BE EXPECTED THRU PERIOD. /VII/

&&

.PRELIMINARY POINT TEMPS/POPS...
SHV  71  82  70  86 /  70  70  30  30
MLU  72  81  69  86 /  60  70  30  40
DEQ  68  83  67  82 /  60  40  30  30
TXK  70  83  68  83 /  70  50  30  30
ELD  70  81  68  84 /  70  70  30  30
TYR  71  82  69  85 /  60  50  20  30
GGG  70  82  69  86 /  70  60  20  30
LFK  72  82  71  88 /  40  70  20  40

&&

.SHV WATCHES/WARNINGS/ADVISORIES...
AR...FLASH FLOOD WATCH FROM 10 PM CDT THIS EVENING THROUGH MONDAY
     AFTERNOON FOR ARZ050-051-059>061-070>073.

LA...FLASH FLOOD WATCH FROM 10 PM CDT THIS EVENING THROUGH MONDAY
     AFTERNOON FOR LAZ001>006-010>012.

OK...FLASH FLOOD WATCH FROM 10 PM CDT THIS EVENING THROUGH MONDAY
     AFTERNOON FOR OKZ077.

TX...FLASH FLOOD WATCH FROM 10 PM CDT THIS EVENING THROUGH MONDAY
     AFTERNOON FOR TXZ096-097-108>112-124>126-136>138-149>153.

&&

$$

15




AREA FORECAST DISCUSSION

NWS LAKE CHARLES LA

 1231 PM CDT SUN MAY 17 2015

.DISCUSSION...
18Z TAF ISSUANCE.

&&

.AVIATION...
S WINDS ~14-17 KTS WITH GUSTS AROUND 25 KTS OR HIGHER EXPECTED
THIS AFTERNOON AS THE PRESSURE GRADIENT REMAINS TIGHT WITH HIGH
PRESSURE OFF THE EAST COAST AND LOW PRESSURE TROF OVER THE CENTRAL
PLAINS. RADAR SHOWS SCT SHRA/TSRA ACROSS SE TX/C LA...WITH THE
HIGHEST CHANCES FOR AEX/BPT/LCH AT 40-50% THIS AFTERNOON...SLIGHTLY
LESS CHANCES AT LFT/ARA...BUT STILL EXPECTING AROUND 30%. FOR
THIS...TEMPO GROUP FOR INTERMITTENT TSRA & MVFR CEILINGS FROM
18-22Z AT AEX/BPT/LCH. FOR THIS EVENING...ONLY VCSH EXPECTED
AFTER THE LOSS OF DAYTIME HEATING. EXPECT MVFR CEILINGS BY
06Z...WITH INTERMITTENT IFR CEILINGS FROM 10-14Z MON.

DML

&&

.PREV DISCUSSION... /ISSUED 1021 AM CDT SUN MAY 17 2015/

UPDATE...
IR SATELLITE SHOWING SOME CLOUD TOP WARMING PERHAPS SIGNALING AN
OVERALL WEAKENING TREND IN A LINE OF SHOWERS AND THUNDERSTORMS
NOTED ON RADAR THIS MORNING ALONG A TOMBALL...HUNSTVILLE...LUFKIN
TX LINE. INSTABILITY IS APPARENT AHEAD OF THIS LINE AS SCATTERED
SHOWERS ARE DEVELOPING ACROSS INTERIOR SOUTHEAST TEXAS EXTENDING
SOUTHWEST INTO THE HOUSTON AREA.

CURRENT FORECAST ON TRACK AS POPS IN LINE WHERE CONVECTION IS
DEVELOPING AND IS FORECAST TO CONTINUE TO DEVELOP MOSTLY ACROSS
OUR NORTHERN AREAS. SOUTHERN AREAS ALONG AND SOUTH OF I-10
CORRIDOR WILL SEE A SLIGHT CHANCE OF AFTERNOON CONVECTION BUT
BELIEVE MID AND HIGH CLOUDS MAY LIMIT ANYTHING MORE.

NO CHANGES FOR ZONE FORECAST PACKAGE. 06

PREV DISCUSSION... /ISSUED 701 AM CDT SUN MAY 17 2015/

DISCUSSION...
17/12Z TAF ISSUANCE.

AVIATION...
OTHER THAN SOME SHRA EAST OF THE LOWER ATCHAFALAYA BASIN...KLCH
88D SHOWS LITTLE CONVECTION ACRS THE AREA THIS MORNING. WIDESPREAD
LOW CLOUDS WITH BKN CIGS PREVAILING BETWEEN 1000-2000 FT. EXPECT
CIGS TO LIFT TO VFR THROUGH MIDDAY WITH SCT CONVECTION DEVELOPING
AS DAYTIME HEATING INTERACTS WITH A PASSING DISTURBANCE ALOFT AND
AN APPROACHING SFC BOUNDARY OVER TX. GUSTY SLY WINDS CAN AGAIN BE
EXPECTED.

CURRENTLY...A LINE OF STORMS EXTENDS FM NE TX SW TO THE RIO
GRANDE VALLEY. THIS LINE WILL APPROACH SE TX LATER THIS MORNING
AND COULD AFFECT BPT BY MIDDAY IF IT HOLDS TOGETHER. BOTH THE NAM
AND HRRR INDICATE THE NRN END OF THE LINE SHOULD REACH PORTIONS OF
NRN/CNTL LA AS WELL...THUS INCLUDED TEMPO GROUPS AT BOTH AEX AND
BPT. INSERTED PROB30 AFTER 21Z FOR LCH WITH VC AT LFT/ARA AS
UNCERTAINTY INCREASES REGARDING CONVECTIVE EVOLUTION THROUGH THE
AFTN. ACTIVITY SHOULD DIMINISH DURING THE EVENING WITH THE LOSS OF
DAYTIME HEATING...WITH MVFR CIGS RETURNING AFTER MIDNIGHT. 24

PREV DISCUSSION... /ISSUED 343 AM CDT SUN MAY 17 2015/

DISCUSSION...
WATER VAPOR CURRENTLY SHOWING SOME DRIER AIR AND SUBSIDENCE ALOFT
ACROSS THE FORECAST AREA...AND LOCAL RADARS ARE ON THE QUIET SIDE
OVER THE IMMEDIATE FORECAST AREA...WITH JUST AN OCCASIONAL LIGHT
POP-UP NOCTURNAL SHOWER.

THE THINKING FOR THE PAST COUPLE OF DAYS HAD BEEN THAT SUNDAY
WOULD SEE LESS ACTIVITY BASED ON THE SOMEWHAT DRIER AIR IN THE MID
LEVELS AND FORECAST AREA WOULD BE BETWEEN SYSTEMS.
HOWEVER...REGIONAL RADAR IMAGES SHOW CLUSTERS OF THUNDERSTORMS
ALONG A LINE EXTENDING FROM THE RED RIVER VALLEY THROUGH CENTRAL
TEXAS JUST WEST OF I-35. THIS ACTIVITY IS NOTED ALONG A SURFACE
TROUGH WITH ENERGY FROM AN UPPER LEVEL DISTURBANCE AT IT KICKS
OUT. PROGS...ESPECIALLY THE LATEST HRRR...IS RATHER BULLISH WITH
KEEPING ACTIVITY TOGETHER AND REACHING THE NORTHERN PORTIONS OF
THE FORECAST AREA THIS AFTERNOON. THEREFORE...WILL HAVE HIGH END
CHANCE FOR SHOWERS AND STORMS ACROSS UPPER SOUTHEAST TEXAS...AND
NORTH OF HIGHWAY 190 IN LOUISIANA...FOR THIS AFTERNOON...WITH LOW
END CHANCE SOUTH OF THIS LINE TO THE COAST. THE MAIN HAZARD WILL
BE LOCALLY HEAVY RAINFALL AND OCCASIONAL TO FREQUENT CLOUD TO
GROUND LIGHTNING.

ACTIVITY THAT DEVELOPS WILL DECREASE IN THE EVENING HOURS WITH THE
LOSS OF DAYTIME HEATING.

AS THE UPPER LEVEL TROUGH CONTINUES TO KICK OFF TO THE NORTHEAST
ON MONDAY...IT WILL PUSH A SURFACE TROUGH INTO THE FORECAST AREA
WHERE IT WILL STALL ROUGHLY ALONG HIGHWAY 190 AND WASH OUT ON
TUESDAY. THE COMBINATION OF A VERY MOIST ENVIRONMENT AND LIFT FROM
THE TROUGH...WILL PRODUCE DECENT RAIN CHANCES...ESPECIALLY
NORTHERN ZONES ON MONDAY INTO TUESDAY...WITH THE BEST CHANCE
DURING THE AFTERNOON...ALTHOUGH ACTIVITY COULD DEVELOP DURING ANY
PART OF THE DAY. CLOUD COVER MAY LIMIT INSTABILITY...ALONG WITH
UPPER LEVEL ENERGY ON THE MODEST SIDE...AND THIS MAY KEEP STORMS
IN CHECK...WITH AGAIN THE MAIN CONCERNS THE HEAVY RAINFALL
POTENTIAL...WITH PWAT BETWEEN 1.8 AND 2 INCHES...AND MEAN RH IN
THE 70 TO 80 PERCENT RANGE.

THE SURFACE BOUNDARY WILL WASH-OUT BY WEDNESDAY...AND WEAK FLAT
UPPER LEVEL RIDGING WILL TRY TO BUILD INTO THE FORECAST AREA.
STILL...PLENTY OF MOISTURE WITH SOUTH FLOW OFF THE GULF. MAIN
KICKER WILL BE DAYTIME HEATING...SO WILL HAVE TYPICAL SUMMERTIME
CONVECTION TYPE POPS FOR THE REMAINDER OF THE FORECAST TO COVER
DIURNAL DRIVEN STORMS.

RUA

MARINE...
MODERATE SOUTHEAST FLOW OCCURRING OVER THE COASTAL WATERS THIS
EARLY MORNING WITH NOCTURNAL LOW LEVEL JET AND INFLOW INTO TROUGH
AND COMPLEX OF STORMS OVER THE RED RIVER VALLEY INTO CENTRAL
TEXAS. SUSTAINED WINDS AT TIMES NEAR 20 KNOTS...AND PROGS SHOW
THIS CONTINUING THROUGH THE MORNING HOURS...UNTIL TROUGH GETS
CLOSER TO THE REGION. THEREFORE...WILL EXTEND SMALL CRAFT EXERCISE
CAUTION THROUGH THE MORNING HOURS.

WINDS AWAY FROM CONVECTION WILL DECREASE LATER THIS AFTERNOON INTO
MONDAY AS SURFACE TROUGH NEARS THE FORECAST AREA...LESSENING THE
GRADIENT ACROSS THE COASTAL WATERS. THIS SURFACE TROUGH WILL STALL
AND WASH OUT NORTH OF THE COASTAL WATERS LATE MONDAY INTO TUESDAY.
THEREFORE...WITH HIGH PRESSURE AT THE SURFACE ANCHORED OFF THE
SOUTHEAST U.S. COAST...SOUTH TO SOUTHEAST WINDS WILL PREVAIL AT
LIGHT TO OCCASIONALLY MODERATE LEVELS THROUGH THE FORECAST PERIOD.

SHOWERS AND THUNDERSTORMS ARE EXPECTED TO INCREASE LATER TODAY AND
MONDAY...WITH UNSTABLE CONDITIONS PREVAILING INTO TUESDAY...AS THE
TROUGH INTERACTS WITH THE MOIST ENVIRONMENT TO PRODUCE SCATTERED
SHOWERS AND THUNDERSTORMS...ESPECIALLY NEAR SHORE OR OVER THE
COASTAL LAKES. WINDS AND SEAS WILL BE LOCALLY HIGHER NEAR THE
STORMS. THE CONVECTION WILL DECREASE IN COVERAGE FOR THE MIDDLE TO
LATE PART OF THE WEEK.

RUA

&&

.PRELIMINARY POINT TEMPS/POPS...
AEX  73  85  70  86 /  20  60  40  50
LCH  76  87  74  86 /  20  40  20  40
LFT  75  87  73  86 /  20  50  30  40
BPT  76  88  74  86 /  20  40  20  30

&&

.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&

$$


AVIATION...08




AREA FORECAST DISCUSSION

NWS LAKE CHARLES LA

 1021 AM CDT SUN MAY 17 2015

.UPDATE...
IR SATELLITE SHOWING SOME CLOUD TOP WARMING PERHAPS SIGNALING AN
OVERALL WEAKENING TREND IN A LINE OF SHOWERS AND THUNDERSTORMS
NOTED ON RADAR THIS MORNING ALONG A TOMBALL...HUNSTVILLE...LUFKIN
TX LINE. INSTABILITY IS APPARENT AHEAD OF THIS LINE AS SCATTERED
SHOWERS ARE DEVELOPING ACROSS INTERIOR SOUTHEAST TEXAS EXTENDING
SOUTHWEST INTO THE HOUSTON AREA.

CURRENT FORECAST ON TRACK AS POPS IN LINE WHERE CONVECTION IS
DEVELOPING AND IS FORECAST TO CONTINUE TO DEVELOP MOSTLY ACROSS
OUR NORTHERN AREAS. SOUTHERN AREAS ALONG AND SOUTH OF I-10
CORRIDOR WILL SEE A SLIGHT CHANCE OF AFTERNOON CONVECTION BUT
BELIEVE MID AND HIGH CLOUDS MAY LIMIT ANYTHING MORE.

NO CHANGES FOR ZONE FORECAST PACKAGE. 06

&&

.PREV DISCUSSION... /ISSUED 701 AM CDT SUN MAY 17 2015/

DISCUSSION...
17/12Z TAF ISSUANCE.

AVIATION...
OTHER THAN SOME SHRA EAST OF THE LOWER ATCHAFALAYA BASIN...KLCH
88D SHOWS LITTLE CONVECTION ACRS THE AREA THIS MORNING. WIDESPREAD
LOW CLOUDS WITH BKN CIGS PREVAILING BETWEEN 1000-2000 FT. EXPECT
CIGS TO LIFT TO VFR THROUGH MIDDAY WITH SCT CONVECTION DEVELOPING
AS DAYTIME HEATING INTERACTS WITH A PASSING DISTURBANCE ALOFT AND
AN APPROACHING SFC BOUNDARY OVER TX. GUSTY SLY WINDS CAN AGAIN BE
EXPECTED.

CURRENTLY...A LINE OF STORMS EXTENDS FM NE TX SW TO THE RIO
GRANDE VALLEY. THIS LINE WILL APPROACH SE TX LATER THIS MORNING
AND COULD AFFECT BPT BY MIDDAY IF IT HOLDS TOGETHER. BOTH THE NAM
AND HRRR INDICATE THE NRN END OF THE LINE SHOULD REACH PORTIONS OF
NRN/CNTL LA AS WELL...THUS INCLUDED TEMPO GROUPS AT BOTH AEX AND
BPT. INSERTED PROB30 AFTER 21Z FOR LCH WITH VC AT LFT/ARA AS
UNCERTAINTY INCREASES REGARDING CONVECTIVE EVOLUTION THROUGH THE
AFTN. ACTIVITY SHOULD DIMINISH DURING THE EVENING WITH THE LOSS OF
DAYTIME HEATING...WITH MVFR CIGS RETURNING AFTER MIDNIGHT. 24

PREV DISCUSSION... /ISSUED 343 AM CDT SUN MAY 17 2015/

DISCUSSION...
WATER VAPOR CURRENTLY SHOWING SOME DRIER AIR AND SUBSIDENCE ALOFT
ACROSS THE FORECAST AREA...AND LOCAL RADARS ARE ON THE QUIET SIDE
OVER THE IMMEDIATE FORECAST AREA...WITH JUST AN OCCASIONAL LIGHT
POP-UP NOCTURNAL SHOWER.

THE THINKING FOR THE PAST COUPLE OF DAYS HAD BEEN THAT SUNDAY
WOULD SEE LESS ACTIVITY BASED ON THE SOMEWHAT DRIER AIR IN THE MID
LEVELS AND FORECAST AREA WOULD BE BETWEEN SYSTEMS.
HOWEVER...REGIONAL RADAR IMAGES SHOW CLUSTERS OF THUNDERSTORMS
ALONG A LINE EXTENDING FROM THE RED RIVER VALLEY THROUGH CENTRAL
TEXAS JUST WEST OF I-35. THIS ACTIVITY IS NOTED ALONG A SURFACE
TROUGH WITH ENERGY FROM AN UPPER LEVEL DISTURBANCE AT IT KICKS
OUT. PROGS...ESPECIALLY THE LATEST HRRR...IS RATHER BULLISH WITH
KEEPING ACTIVITY TOGETHER AND REACHING THE NORTHERN PORTIONS OF
THE FORECAST AREA THIS AFTERNOON. THEREFORE...WILL HAVE HIGH END
CHANCE FOR SHOWERS AND STORMS ACROSS UPPER SOUTHEAST TEXAS...AND
NORTH OF HIGHWAY 190 IN LOUISIANA...FOR THIS AFTERNOON...WITH LOW
END CHANCE SOUTH OF THIS LINE TO THE COAST. THE MAIN HAZARD WILL
BE LOCALLY HEAVY RAINFALL AND OCCASIONAL TO FREQUENT CLOUD TO
GROUND LIGHTNING.

ACTIVITY THAT DEVELOPS WILL DECREASE IN THE EVENING HOURS WITH THE
LOSS OF DAYTIME HEATING.

AS THE UPPER LEVEL TROUGH CONTINUES TO KICK OFF TO THE NORTHEAST
ON MONDAY...IT WILL PUSH A SURFACE TROUGH INTO THE FORECAST AREA
WHERE IT WILL STALL ROUGHLY ALONG HIGHWAY 190 AND WASH OUT ON
TUESDAY. THE COMBINATION OF A VERY MOIST ENVIRONMENT AND LIFT FROM
THE TROUGH...WILL PRODUCE DECENT RAIN CHANCES...ESPECIALLY
NORTHERN ZONES ON MONDAY INTO TUESDAY...WITH THE BEST CHANCE
DURING THE AFTERNOON...ALTHOUGH ACTIVITY COULD DEVELOP DURING ANY
PART OF THE DAY. CLOUD COVER MAY LIMIT INSTABILITY...ALONG WITH
UPPER LEVEL ENERGY ON THE MODEST SIDE...AND THIS MAY KEEP STORMS
IN CHECK...WITH AGAIN THE MAIN CONCERNS THE HEAVY RAINFALL
POTENTIAL...WITH PWAT BETWEEN 1.8 AND 2 INCHES...AND MEAN RH IN
THE 70 TO 80 PERCENT RANGE.

THE SURFACE BOUNDARY WILL WASH-OUT BY WEDNESDAY...AND WEAK FLAT
UPPER LEVEL RIDGING WILL TRY TO BUILD INTO THE FORECAST AREA.
STILL...PLENTY OF MOISTURE WITH SOUTH FLOW OFF THE GULF. MAIN
KICKER WILL BE DAYTIME HEATING...SO WILL HAVE TYPICAL SUMMERTIME
CONVECTION TYPE POPS FOR THE REMAINDER OF THE FORECAST TO COVER
DIURNAL DRIVEN STORMS.

RUA

MARINE...
MODERATE SOUTHEAST FLOW OCCURRING OVER THE COASTAL WATERS THIS
EARLY MORNING WITH NOCTURNAL LOW LEVEL JET AND INFLOW INTO TROUGH
AND COMPLEX OF STORMS OVER THE RED RIVER VALLEY INTO CENTRAL
TEXAS. SUSTAINED WINDS AT TIMES NEAR 20 KNOTS...AND PROGS SHOW
THIS CONTINUING THROUGH THE MORNING HOURS...UNTIL TROUGH GETS
CLOSER TO THE REGION. THEREFORE...WILL EXTEND SMALL CRAFT EXERCISE
CAUTION THROUGH THE MORNING HOURS.

WINDS AWAY FROM CONVECTION WILL DECREASE LATER THIS AFTERNOON INTO
MONDAY AS SURFACE TROUGH NEARS THE FORECAST AREA...LESSENING THE
GRADIENT ACROSS THE COASTAL WATERS. THIS SURFACE TROUGH WILL STALL
AND WASH OUT NORTH OF THE COASTAL WATERS LATE MONDAY INTO TUESDAY.
THEREFORE...WITH HIGH PRESSURE AT THE SURFACE ANCHORED OFF THE
SOUTHEAST U.S. COAST...SOUTH TO SOUTHEAST WINDS WILL PREVAIL AT
LIGHT TO OCCASIONALLY MODERATE LEVELS THROUGH THE FORECAST PERIOD.

SHOWERS AND THUNDERSTORMS ARE EXPECTED TO INCREASE LATER TODAY AND
MONDAY...WITH UNSTABLE CONDITIONS PREVAILING INTO TUESDAY...AS THE
TROUGH INTERACTS WITH THE MOIST ENVIRONMENT TO PRODUCE SCATTERED
SHOWERS AND THUNDERSTORMS...ESPECIALLY NEAR SHORE OR OVER THE
COASTAL LAKES. WINDS AND SEAS WILL BE LOCALLY HIGHER NEAR THE
STORMS. THE CONVECTION WILL DECREASE IN COVERAGE FOR THE MIDDLE TO
LATE PART OF THE WEEK.

RUA

&&

.PRELIMINARY POINT TEMPS/POPS...
AEX  88  73  85  70 /  50  20  60  40
LCH  87  76  87  74 /  30  20  40  20
LFT  87  75  87  73 /  30  20  50  30
BPT  86  76  88  74 /  30  20  40  20

&&

.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...SMALL CRAFT EXERCISE CAUTION UNTIL NOON CDT TODAY FOR GMZ450-452-
     455-470-472-475.

&&

$$

PUBLIC...06



AREA FORECAST DISCUSSION

NWS LAKE CHARLES LA

 701 AM CDT SUN MAY 17 2015

.DISCUSSION...
17/12Z TAF ISSUANCE.

&&

.AVIATION...
OTHER THAN SOME SHRA EAST OF THE LOWER ATCHAFALAYA BASIN...KLCH
88D SHOWS LITTLE CONVECTION ACRS THE AREA THIS MORNING. WIDESPREAD
LOW CLOUDS WITH BKN CIGS PREVAILING BETWEEN 1000-2000 FT. EXPECT
CIGS TO LIFT TO VFR THROUGH MIDDAY WITH SCT CONVECTION DEVELOPING
AS DAYTIME HEATING INTERACTS WITH A PASSING DISTURBANCE ALOFT AND
AN APPROACHING SFC BOUNDARY OVER TX. GUSTY SLY WINDS CAN AGAIN BE
EXPECTED.

CURRENTLY...A LINE OF STORMS EXTENDS FM NE TX SW TO THE RIO
GRANDE VALLEY. THIS LINE WILL APPROACH SE TX LATER THIS MORNING
AND COULD AFFECT BPT BY MIDDAY IF IT HOLDS TOGETHER. BOTH THE NAM
AND HRRR INDICATE THE NRN END OF THE LINE SHOULD REACH PORTIONS OF
NRN/CNTL LA AS WELL...THUS INCLUDED TEMPO GROUPS AT BOTH AEX AND
BPT. INSERTED PROB30 AFTER 21Z FOR LCH WITH VC AT LFT/ARA AS
UNCERTAINTY INCREASES REGARDING CONVECTIVE EVOLUTION THROUGH THE
AFTN. ACTIVITY SHOULD DIMINISH DURING THE EVENING WITH THE LOSS OF
DAYTIME HEATING...WITH MVFR CIGS RETURNING AFTER MIDNIGHT. 24

&&

.PREV DISCUSSION... /ISSUED 343 AM CDT SUN MAY 17 2015/

DISCUSSION...
WATER VAPOR CURRENTLY SHOWING SOME DRIER AIR AND SUBSIDENCE ALOFT
ACROSS THE FORECAST AREA...AND LOCAL RADARS ARE ON THE QUIET SIDE
OVER THE IMMEDIATE FORECAST AREA...WITH JUST AN OCCASIONAL LIGHT
POP-UP NOCTURNAL SHOWER.

THE THINKING FOR THE PAST COUPLE OF DAYS HAD BEEN THAT SUNDAY
WOULD SEE LESS ACTIVITY BASED ON THE SOMEWHAT DRIER AIR IN THE MID
LEVELS AND FORECAST AREA WOULD BE BETWEEN SYSTEMS.
HOWEVER...REGIONAL RADAR IMAGES SHOW CLUSTERS OF THUNDERSTORMS
ALONG A LINE EXTENDING FROM THE RED RIVER VALLEY THROUGH CENTRAL
TEXAS JUST WEST OF I-35. THIS ACTIVITY IS NOTED ALONG A SURFACE
TROUGH WITH ENERGY FROM AN UPPER LEVEL DISTURBANCE AT IT KICKS
OUT. PROGS...ESPECIALLY THE LATEST HRRR...IS RATHER BULLISH WITH
KEEPING ACTIVITY TOGETHER AND REACHING THE NORTHERN PORTIONS OF
THE FORECAST AREA THIS AFTERNOON. THEREFORE...WILL HAVE HIGH END
CHANCE FOR SHOWERS AND STORMS ACROSS UPPER SOUTHEAST TEXAS...AND
NORTH OF HIGHWAY 190 IN LOUISIANA...FOR THIS AFTERNOON...WITH LOW
END CHANCE SOUTH OF THIS LINE TO THE COAST. THE MAIN HAZARD WILL
BE LOCALLY HEAVY RAINFALL AND OCCASIONAL TO FREQUENT CLOUD TO
GROUND LIGHTNING.

ACTIVITY THAT DEVELOPS WILL DECREASE IN THE EVENING HOURS WITH THE
LOSS OF DAYTIME HEATING.

AS THE UPPER LEVEL TROUGH CONTINUES TO KICK OFF TO THE NORTHEAST
ON MONDAY...IT WILL PUSH A SURFACE TROUGH INTO THE FORECAST AREA
WHERE IT WILL STALL ROUGHLY ALONG HIGHWAY 190 AND WASH OUT ON
TUESDAY. THE COMBINATION OF A VERY MOIST ENVIRONMENT AND LIFT FROM
THE TROUGH...WILL PRODUCE DECENT RAIN CHANCES...ESPECIALLY
NORTHERN ZONES ON MONDAY INTO TUESDAY...WITH THE BEST CHANCE
DURING THE AFTERNOON...ALTHOUGH ACTIVITY COULD DEVELOP DURING ANY
PART OF THE DAY. CLOUD COVER MAY LIMIT INSTABILITY...ALONG WITH
UPPER LEVEL ENERGY ON THE MODEST SIDE...AND THIS MAY KEEP STORMS
IN CHECK...WITH AGAIN THE MAIN CONCERNS THE HEAVY RAINFALL
POTENTIAL...WITH PWAT BETWEEN 1.8 AND 2 INCHES...AND MEAN RH IN
THE 70 TO 80 PERCENT RANGE.

THE SURFACE BOUNDARY WILL WASH-OUT BY WEDNESDAY...AND WEAK FLAT
UPPER LEVEL RIDGING WILL TRY TO BUILD INTO THE FORECAST AREA.
STILL...PLENTY OF MOISTURE WITH SOUTH FLOW OFF THE GULF. MAIN
KICKER WILL BE DAYTIME HEATING...SO WILL HAVE TYPICAL SUMMERTIME
CONVECTION TYPE POPS FOR THE REMAINDER OF THE FORECAST TO COVER
DIURNAL DRIVEN STORMS.

RUA

MARINE...
MODERATE SOUTHEAST FLOW OCCURRING OVER THE COASTAL WATERS THIS
EARLY MORNING WITH NOCTURNAL LOW LEVEL JET AND INFLOW INTO TROUGH
AND COMPLEX OF STORMS OVER THE RED RIVER VALLEY INTO CENTRAL
TEXAS. SUSTAINED WINDS AT TIMES NEAR 20 KNOTS...AND PROGS SHOW
THIS CONTINUING THROUGH THE MORNING HOURS...UNTIL TROUGH GETS
CLOSER TO THE REGION. THEREFORE...WILL EXTEND SMALL CRAFT EXERCISE
CAUTION THROUGH THE MORNING HOURS.

WINDS AWAY FROM CONVECTION WILL DECREASE LATER THIS AFTERNOON INTO
MONDAY AS SURFACE TROUGH NEARS THE FORECAST AREA...LESSENING THE
GRADIENT ACROSS THE COASTAL WATERS. THIS SURFACE TROUGH WILL STALL
AND WASH OUT NORTH OF THE COASTAL WATERS LATE MONDAY INTO TUESDAY.
THEREFORE...WITH HIGH PRESSURE AT THE SURFACE ANCHORED OFF THE
SOUTHEAST U.S. COAST...SOUTH TO SOUTHEAST WINDS WILL PREVAIL AT
LIGHT TO OCCASIONALLY MODERATE LEVELS THROUGH THE FORECAST PERIOD.

SHOWERS AND THUNDERSTORMS ARE EXPECTED TO INCREASE LATER TODAY AND
MONDAY...WITH UNSTABLE CONDITIONS PREVAILING INTO TUESDAY...AS THE
TROUGH INTERACTS WITH THE MOIST ENVIRONMENT TO PRODUCE SCATTERED
SHOWERS AND THUNDERSTORMS...ESPECIALLY NEAR SHORE OR OVER THE
COASTAL LAKES. WINDS AND SEAS WILL BE LOCALLY HIGHER NEAR THE
STORMS. THE CONVECTION WILL DECREASE IN COVERAGE FOR THE MIDDLE TO
LATE PART OF THE WEEK.

RUA

&&

.PRELIMINARY POINT TEMPS/POPS...
AEX  88  73  85  70 /  50  20  60  40
LCH  87  76  87  74 /  30  20  40  20
LFT  87  75  87  73 /  30  20  50  30
BPT  86  76  88  74 /  30  20  40  20

&&

.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...SMALL CRAFT EXERCISE CAUTION UNTIL NOON CDT TODAY FOR GMZ450-452-
     455-470-472-475.

&&

$$

PUBLIC...07
AVIATION...24




AREA FORECAST DISCUSSION

NWS SHREVEPORT LA

 1210 AM CDT SUN MAY 17 2015

.AVIATION...

TERMINAL FORECAST SITES WILL START OUT WITH PREVAILING VFR...BUT
WITH A STRONG SOUTHERLY FLOW IN THE LOWER LEVELS...MVFR CEILINGS
WILL SPREAD AND DEVELOP OVER THE FOUR STATE REGION SHORTLY AFTER
17/06Z TO 17/09Z. IFR CONDITIONS WILL FOLLOW ACROSS THE REGION
AND WILL BE SLOW TO RETURN TO MVFR DURING THE MID TO LATE MORNING.
VFR MAY BE RETURNING NEAR MID DAY. SHOWERS AND THUNDERWSTORMS
WILL BE MOVING INTO THE EAST AND NORTHEAST TEXAS AND SOUTHWEST
ARKANSAS TERMINALS AFTER 17/09Z TO 17/11Z WITH SHOWERS ACROSS
NORTH LOUISIANA AND SOUTH CENTRAL ARKANSAS. THUNDERST0RMS WILL BE
SPREADING AND DEEVELOPING OVER THE LOUISIANA AND SOUTH CETNRAL
ARKANSAS SITES NEAR LATE AFTERNOON INTO THE EARLY EVENING. WINDS
WILL BE SOUTH 7-13 KNOTS THROUGH 17/14Z THEN INCREASE TO 10-15
KNOTS WITH HIGHER GUSTS ESPECIALLY FOR PARTS OF EAST AND NORTHEAST
TEXAS AND ADJACENT SOUTHWEST ARKANSAS. /06/

PREV DISCUSSION... /ISSUED 933 PM CDT SAT MAY 16 2015/

DISCUSSION...
SEABREEZE CONVECTION DISSIPATED QUICKLY THIS EVENING AND WITH A
CLEAR SCOPE CURRENTLY...HAVE REDUCED POPS THROUGH MIDNIGHT TO
SLIGHT CHANCE VARIETY. THE BIGGER SHOW IS GOING ON TO OUR WEST
WHERE DISCRETE SEVERE THUNDERSTORMS ARE TRYING TO DEVELOP INTO A
BROKEN LINE OF SEVERE CONVECTION...ESPECIALLY ACROSS CENTRAL
OKLAHOMA. LATEST HRRR OUTPUT DOES NOT BRING THIS CONVECTION INTO
OUR EXTREME NW ZONES UNTIL JUST BEFORE 12Z SO HAVE ADJUSTED THE
EXPECTED EASTWARD PROGRESSION OF THIS ACTIVITY WITH THE GRIDS.

LOCAL HEAVY RAINFALL WORDING WAS SHIFTED FURTHER NORTH AND WEST
FROM THE 06-12Z TIMEFRAME AND ADDED THIS MENTION SLIGHTLY FURTHER
EAST DURING THE 12-18Z SUNDAY TIMEFRAME. DID NOT MAKE ANY
ADJUSTMENTS TO THE FFA WHICH WILL GO INTO EFFECT AT 06Z IN THE
MORNING.

OTHER CHANGES INCLUDED SKY GRIDS AND COSMETIC CHANGES TO
WIND/DEWPOINT AND RH GRIDS. OTHERWISE...NO ADDITIONAL CHANGES WERE
NECESSARY THIS EVENING.

UPDATED PACKAGE ALREADY SENT...13.

PREV DISCUSSION... /ISSUED 317 PM CDT SAT MAY 16 2015/

DISCUSSION...
SCATTERED SEA BREEZE TYPE CONVECTION MARCHING NWD THIS AFTN...AND
BEGINNING TO KICK OFF GUSTS FRONTS WITH 30 TO 40 MPH WINDS. DRY
MID LVLS WILL KEEP COVERAGE SCATTERED...UNTIL OVERNIGHT MCS MOVES
DOWN RED RIVER VALLEY. THIS ACTIVITY SHOULD NOT REACH AREA UNTIL
JUST AFTER MIDNIGHT...BUT ADDED NW CORNER OF CWA IN LATE EVE FOR
LIKELY POPS JUST IN CASE...AND LEAVING SOUTHERN SECTIONS AS SLIGHT
CHANCE THIS EVE...WITH AIRMASS MORE WORKED OVER FROM CONVECTION.
FLASH FLOOD WATCH FOR NW SECTIONS OF AREA BEGINNING AT 1 AM. ADDED
LOCALLY HEAVY RAINFALL WITH MCS FOR THOSE SECTIONS...WITH
SATURATED GROUND...JUST A COUPLE INCHES OF RAIN COULD BE A REAL
ISSUE. DEEP SFC LOW MOVG THRU UPPER MIDWEST WILL DRAG ATTENDANT
FRONT ACROSS SOUTHERN PLAINS SUNDAY NIGHT...SWINGING AN EVEN
STRONGER MCS INTO OUR AREA...WHICH SHOULD SPREAD OUT AND BRING
RAIN TO MOST OF THE REGION MONDAY. WILL LIKELY NEED TO REISSUE
FLASH FLOOD WATCH WHICH WILL EXPIRE SUNDAY AT 1 PM...AS PREVIOUS
MCS WILL DIMINISH...AND SHOULD GET A RAIN BREAK FOR AIRMASS TO
RECOVER. SLIGHTLY COOLER AIR IN ZONAL FLOW ALOFT TUESDAY WILL
AFFECT TEMPS SLIGHTLY...AND BRING LOWER RAIN CHANCES TO AREA..BUT
NOT FOR LONG AS FRONT IS EXPECTED TO MEANDER BACK INTO REGION AND
BECOME QUASI STNRY AGAIN BY MID WEEK.

VII

PREV DISCUSSION... /ISSUED 101 PM CDT SAT MAY 16 2015/

AVIATION...
CIGS HAVE BECOME VFR AS OF MIDDAY OVER ALL THE REGION EXCEPT FOR
SCNTRL AR/NE LA...WITH THESE MVFR CIGS OVER THE E EXPECTED TO
BECOME VFR SHORTLY. HOWEVER...SCT CONVECTION HAS DEVELOPED OVER
DEEP E TX INTO N LA/SW AR EARLY THIS AFTERNOON...WITH THIS TREND
EXPECTED TO CONTINUE THROUGH THE REMAINDER OF THE AFTERNOON
AFFECTING ALL BUT THE TYR AND POSSIBLY TXK TERMINAL. LOCALLY GUSTY
WINDS...MVFR CIGS/REDUCED VSBYS...AND SVR TURBULENCE WILL BE
POSSIBLE IN/NEAR THE CONVECTION...BEFORE THEY DIMINISH SHORTLY
AFTER SUNSET. SHOULD SEE SOME CONVECTIVE DEBRIS LINGER THIS
EVENING...WITH MVFR CIGS EXPECTED TO REDEVELOP/SPREAD N AFTER 06Z
OVER MUCH OF THE REGION. A MCS IS EXPECTED TO DEVELOP LATE THIS
AFTERNOON OVER WCNTRL OK...AND PROGRESS ESE INTO SE OK/EXTREME NE
TX SHORTLY AFTER 06Z...BUT SHOULD GRADUALLY WEAKEN WITH TIME AS IT
ENCOUNTERS A MORE STABLE AIR MASS. HOWEVER...THIS CONVECTION MAY
AFFECT THE TYR/GGG/TXK TERMINALS BETWEEN 09-12Z SUNDAY...AND
SHV/ELD AROUND/SHORTLY AFTER 12Z. HAVE INSERTED MENTION OF VCTS
FOR THESE TERMINALS...WITH ANY ASSOCIATED MESOSCALE BNDRYS
POSSIBLY SCOURING THE LOWER CIGS...ALLOWING FOR A QUICKER RETURN
OF VFR CIGS. THESE SFC BNDRYS MAY EVENTUALLY FOCUS ADDITIONAL SCT
CONVECTION DURING THE AFTERNOON FARTHER SE ACROSS THE
REGION...WITH MVFR CIGS AHEAD OF THE DECAYING COMPLEX EXPECTED TO
LIFT/BECOME VFR BY LATE MORNING. S WINDS 10-15KTS...WITH GUSTS TO
23KTS OVER E TX/SE OK...WILL DIMINISH SLIGHTLY TO 6-12KTS AFTER
00Z. /15/

&&

.PRELIMINARY POINT TEMPS/POPS...
SHV  72  82  69  84 /  60  70  40  40
MLU  72  83  70  84 /  50  70  50  40
DEQ  69  80  67  79 /  70  60  30  30
TXK  70  82  68  80 /  70  60  30  30
ELD  71  81  68  80 /  60  70  40  30
TYR  72  82  69  83 /  60  60  40  40
GGG  72  82  69  84 /  60  70  40  40
LFK  74  83  71  86 /  50  70  50  40

&&

.SHV WATCHES/WARNINGS/ADVISORIES...
AR...FLASH FLOOD WATCH THROUGH THIS AFTERNOON FOR ARZ050-051-059-060-
     070.

LA...NONE.
OK...FLASH FLOOD WATCH THROUGH THIS AFTERNOON FOR OKZ077.

TX...FLASH FLOOD WATCH THROUGH THIS AFTERNOON FOR TXZ096-097-108>112-
     124>126-136>138.

&&

$$

06



AREA FORECAST DISCUSSION

NWS WAKEFIELD VA

 949 PM EDT MON MAY 18 2015

.SYNOPSIS...
HIGH PRESSURE REMAINS ANCHORED OFF THE SOUTHEAST COAST THROUGH
TUESDAY. A COLD FRONT CROSSES THE REGION TUESDAY NIGHT. HIGH
PRESSURE BUILDS INTO THE AREA FROM THE WEST WEDNESDAY THROUGH
THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
LATEST REGIONAL RADAR MOSAIC DEPICTS ISOLATED TO WIDELY SCATTERED
SHOWERS/THUNDERSTORMS ACROSS THE NW COUNTIES...WITH ANOTHER ISOLATED
THUNDERSTORM OVER HOPEWELL AS OF THIS WRITING. BETTER COVERAGE OF
SHOWERS AND THUNDERSTORMS FOUND JUST NORTH OF THE LOCAL AREA.
EARLIER THUNDERSTORMS HAVE LEFT BEHIND SEVERAL BOUNDARIES THIS
EVENING. WARM/HUMID AIRMASS REMAINS IN PLACE...WITH RAP MESOANALYSIS
DEPICTING 1000-1500 J/KG MLCAPE. BETTER FORCING ALOFT ALSO INDICATED
(ALBEIT LIMITED OVER THE LOCAL AREA) AS A SHORTWAVE VISIBLE ON WATER
VAPOR LIFTS ACROSS THE OH VALLEY. EXPECT THE BEST COVERAGE OF
SHOWERS/THUNDERSTORMS TO REMAIN NORTH OF THE LOCAL AREA
TONIGHT...BUT COMBINATION OF OUTFLOW BOUNDARIES AND
WARM/MOIST/RELATIVELY UNSTABLE AIRMASS WILL RESULT IN SLIGHT CHANCE-
CHANCE POPS THRU THE OVERNIGHT PERIOD. STORMS EXPECTED TO REMAIN SUB-
SEVERE DUE TO WEAK SHEAR PROFILES...BUT MEAN FLOW AOB 10 KT WILL
RESULT IN LOCALLY HEAVY RAINFALL.

BACKDOOR FRONT ALSO LOCATED OVER THE MD ERN SHORE THIS
EVENING...WITH ONSHORE FLOW OBSERVED AT OCEAN CITY WITH TEMPS
DROPPING INTO THE MID 60S. FOG OBSERVED DOV/GED/OXB...WITH
ADDITIONAL FOG EXPECTED THANKS TO ONSHORE FLOW. HAVE INCLUDED
AREAS OF FOG GENERALLY EAST OF HIGHWAY 13 IN MD. DO NOT ANTICIPATE
DENSE FOG ATTM. MILD TONIGHT WITH LOWS IN THE UPPER 60S TO AROUND
70 DEGREES. SKIES AVG PARTLY CLOUDY.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
A COLD FRONT MOVING THROUGH THE MIDWEST THIS AFTN WILL REACH THE
SPINE OF THE APPALACHIANS AROUND 12Z TUE. THE COLD FRONT THEN
CROSSES THE LOCAL AREA TUESDAY AFTN/EVE...BEFORE PUSHING OFFSHORE
TUE NIGHT. BULK SHEAR REMAINS MARGINAL AT BEST AND DOWNSLOPE FLOW
ALOFT IS LESS THAN IDEAL FOR WIDESPREAD CONVECTIVE DEVELOPMENT.
HOWEVER...STRONG SFC HEATING PRE-FRONTAL SHOULD YIELD ANOTHER
ROUND OF SCATTERED SHWRS/TSTMS IN THE AFTN/EVE. WARM AND HUMID
AGAIN TUE. HIGHS FROM THE MID 80S TO AROUND 90 (EXCEPT COOLER AT
THE IMMEDIATE COAST). LOWS TUE NIGHT IN THE 60S.

COOL/DRY HIGH PRESSURE BEGINS TO BUILD TOWARD THE AREA FROM THE
WEST ON WEDNESDAY...YIELDING A DRIER/MORE COMFORTABLE DAY WITH
PLENTY OF SUNSHINE. HIGH TEMPS FROM THE MID 70S NORTH TO THE LOW
80S SOUTH. COMFORTABLE WED NIGHT WITH LOWS IN THE MID 50S TO LOW
60S. SHORTWAVE ENERGY DIVES SOUTH INTO THE CAROLINAS ON THURSDAY
WITH WEAK SFC LOW PRESSURE DEVELOPING ALONG A STALLED FRONTAL
BOUNDARY. MOISTURE ASSOCIATED WITH THIS SYSTEM WILL GET SHOVED
NORTHWARD INTO THE LOCAL AREA...ESPECIALLY IN THE AFTN/EVE. WILL
CONTINUE TO CARRY CHC POPS FOR MUCH OF THE AREA. HOWEVER...IT
APPEARS THE HIGHEST LIKELIHOOD OF PCPN WILL BE ACROSS SE PARTS OF
THE FA. PLEASANT TEMPS ON THU WITH HIGHS MOSTLY IN THE 70S.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
MEDIUM RANGE BEGINS WITH LATEST GFS/ECMWF INTO GOOD AGREEMENT WITH
WEAK UPPER TROUGH AXIS CROSSING THE REGION THU NIGHT...AND SFC LOW
PRESSURE SLIDING OFF THE COAST. WILL MAINTAIN LOW CHC POPS THU
NIGHT...AND SLIGHT CHC POPS THROUGH FRI MORNING IN THE FAR SE.
OTHERWISE. HIGH PRESSURE THEN GRADUALLY BUILDS ESE FROM THE UPPER
MIDWEST FRI-SAT...AND SLIDES OFF THE COAST ON SUN. THIS WILL RESULT
IN DRY CONDITIONS WITH COOLER TEMPERATURES FRI/SAT...PARTICULARLY AT
THE COAST ON SAT AS THE STRENGTH OF THE HIGH IS FAIRLY IMPRESSIVE...1030
MB+ AND ONSHORE FLOW INCREASES IN THE AFTN AS A PIECE OF THE HIGH
BECOMES CENTERED JUST OFFSHORE. SKIES WILL AVG MOSTLY SUNNY BOTH
DAYS ASIDE FROM SOME LINGERING CLOUDS FRI MORNING. HIGHS FRI WILL
BE FROM 75-80 F INLAND...TO 70-75 F NEAR THE COAST...TRENDING DOWN
TO THE MID 70S SAT INLAND TO ONLY THE UPPER 60S/LOWER 70S AT THE
COAST. LOWS WILL GENLY RANGE THROUGH THE 50S SAT AND SUN MORNING. FLOW
TURNS AROUND TO THE SSW SUN/MON AS SFC HIGH PUSHES WELL OFFSHORE
AND UPPER RIDGE AXIS MOVES BACK INTO THE REGION. HIGHS WARM BACK
INTO THE LWR 80S INLAND ON SUN...AND 85-90 F BY MON. CONDITIONS
BOTH DAYS WILL BE ABOUT 5 DEGREES COOLER AT THE COAST. WILL KEEP
FORECAST DRY THROUGH MIDDAY MON...THEN CARRY 20-30% POPS ACRS THE
NORTH BY MON AFTN.

&&

.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
VFR CONDITIONS PREVAIL OVER ALL TERMINALS EARLY THIS EVENING.
EARLIER TSTMS AT KECG/KSBY HAVE DISSIPATED. WILL MAINTAIN VCSH AT
KRIC THROUGH 04Z...DUE TO LINGERING INSTABILITY/BOUNDARIES IN THE
AREA...WHCIH COULD LEAD TO THE DEVELOPMENT OF SHWRS/TSTMS. HI RES
MODELS WOULD SUGGEST POTENTIAL FOR SCTD SHWRS/TSTMS ACROSS THE
NORTHERN HALF OF THE AREA WEST OF TBE BAY THROUGH 06Z. BUT NOT
ENOUGH CONFIDENCE AT THIS TIME TO PUT PREVAILING PRECIP IN KRIC
TAF. SHWRS/TSTMS IN THE SHENANDOAH VLY SSWWD TOWARD KROA COULD
MOVE INTO THE REGION AFTER 04Z...AND THIS WILL BE MONITORED.

IFR CONDITIONS HAVE BEEN FORECAST OVERNIGHT AT KECG/KSBY...WHERE
PRECIP FELL THIS AFTERNOON...AND SKIES WILL BE MAINLY CLR WITH
LIGHT WINDS OVERNIGHT. MOIST ONSHORE COMPONENT TO LOW LVL FLOW AT
KSBY WILL ALSO BE A CONTRIBUTING FACTOR. CONTINUED CHCS FOR
SHWRS/TSTMS ON TUESDAY AS COLD FRONT APPROACHES.
HOWEVER...CONFIDENCE LOW ON TIMING/LOCATION...SO HAVE LEFT OUT OF
00Z TAFS.

FRONT MOVES THROUGH TUESDAY NIGHT...WITH CLEARING SKIES AND VFR
CONDITIONS THROUGH WEDNESDAY. NEXT THREAT FOR SHWRS/TSTMS WILL BE
THURSDAY AS A SHORT WAVE TROUGH MOVES ACROSS THE REGION.

&&

.MARINE...
WEAK SFC TROUGH OVER THE WATERS...WITH GENLY A LIGHT ONSHORE FLOW
LESS THAN 10 KT...THOUGH WIND DIRECTIONS ARE SOMEWHAT CHAOTIC DUE
TO SCATTERED TSTMS AND VERY WEAK PRESSURE GRADIENT. WINDS WIND
SHIFT TO BECOME A BIT MORE ORGANIZED FROM THE S/SE LATER THIS
EVENING...AND S/SW OVERNIGHT BUT SPEEDS AVG 10 KT OR LESS WITH
SEAS ONLY 2-3 FT AND WAVES IN THE BAY ONLY AROUND 1 FOOT (1-2 FT
MOUTH OF BAY). A COLD FRONT PUSHES ACROSS THE WATERS LATE TUE
(WITH PSBL SHRAS/TSTMS). WINDS BECOME N-NW POST- FRONTAL TUE
NIGHT. NOT A REAL STRONG COLD FRONT...BUT DOES APPEAR TO BE
SUFFICIENT COOL AIR SURGE TO LEAD TO LOW END SCA CONDITIONS FOR
THE BAY (AND PERHAPS THE RIVERS/SOUND). AT THIS TIME...KEEPING
CONDS BELOW SCA FOR THE OCEAN. IT WILL TEND TO BE FAIRLY SHORT IN
DURATION (AROUND 6 HRS..FROM AROUND 3-4 AM/WED THROUGH LATE
MORNING OR NOON/WED). SFC HI PRES BUILDS INTO THE RGN FM THE W WED
NIGHT...WITH A WEAK LOW PRESSURE SYSTEM PASSING BY TO THE SOUTH ON
THU. SOME UNCERTAINTY ON EXACT TRACK OF THIS SYSTEM...FOR NOW
MODELS KEEP WINDS FAIRLY LIGHT...10-15 KT AT MOST ALTHOUGH THIS
COULD CHANGE. HIGH PRESSURE THEN BUILDS OVER THE AREA LATER FRI-
SUN...FAIRLY COOL AIRMASS INITIALLY WILL LIKELY BRING SOME
INCREASE IN WINDS FRI NIGHT INTO SAT.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...JDM
NEAR TERM...JDM/SAM
SHORT TERM...JDM/MAS
LONG TERM...LKB
AVIATION...WRS
MARINE...LKB




AREA FORECAST DISCUSSION

NWS PITTSBURGH PA

 530 PM EDT SUN MAY 17 2015

.SYNOPSIS...
WARM AND HUMID CONDITIONS WILL CONTINUE UNTIL PASSAGE OF A
TUESDAY COLD FRONT.

&&

.NEAR TERM /THROUGH MONDAY/...
EARLY EVENING UPDATE CENTERED REALLY AROUND LOW LEVEL MOISTURE AND
ITS RAMIFICATIONS FOR THE REST OF THE EVENING AND OVERNIGHT.
PREVIOUS FORECAST COVERED DIURNALLY-DRIVEN SHOWERS/THUNDERSTORMS
WITH LITTLE UPPER SUPPORT FAIRLY WELL...AND STILL SEEMS A-OK.
HOWEVER...LOW LEVEL MOISTURE VIA DEWPOINTS ACROSS OHIO IS ACTUALLY
A BIT STRONGER THAN DEPICTED ON ANY MODEL SOLUTION THIS
EVENING...INCLUDING THE HRRR. DEWPOINTS ACROSS THE BULK OF OHIO
ARE RUNNING IN THE UPPER 60S TO LOWER 70S...AND EVEN IN
PENNSYLVANIA AND WEST VIRGINIA...MID TO UPPER 60S ARE FAIRLY
PREVALENT. GIVEN POOR MIXING AND WEAK CONVECTIVE
OVERTURNING...ALONG WITH WET SOIL FROM RAIN THIS MORNING IN MOST
LOCATIONS...IT WOULD SEEM WE ARE WELL PRIMED FOR FOG DEVELOPMENT
OVERNIGHT. GIVEN BUFKIT SOUNDINGS FROM THE NAM OVER MOST OF THE
AREA EXCEPT MAYBE OUR WESTERNMOST COUNTIES IN OHIO...DECOUPLING
AND STABILIZATION OF THE BOUNDARY LAYER SHOULD LEAD TO SOME FOG
OVERNIGHT. FARTHER WEST TOWARD ZANESVILLE...THE ONLY THING THAT
MAY INHIBIT THIS WOULD BE SOME PRE-FRONTAL TROUGH MIXING OVERNIGHT
TOWARD MORNING. TO ACCOUNT FOR ALL OF THIS...AREAS OF FOG WERE
CARRIED MOST EVERYWHERE OVERNIGHT...EXCEPT AROUND
ZANESVILLE...WHERE JUST PATCHY FOG WAS CARRIED.

OTHERWISE...THE PREVIOUS FORECAST HANDLES THE SLOW DEMISE OF
THUNDERSTORMS INTO ISOLATED SHOWERS OVERNIGHT WITH FAIRLY STABLE
TEMPERATURES IN THE MID AND UPPER 60S. FRIES

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
AS PRE-FRONTAL TROUGH SHIFTS EAST MONDAY EVENING IT WILL TAKE MOST
OF THE DEEP MOISTURE WITH IT. POPS WILL BE IN THE CHANCE CATEGORY
AFTER MONDAY EVENING AS MAIN FRONT PUSHES EAST EARLY TUESDAY. DEW
POINTS WILL REMAIN A BIT ELEVATED UNTIL FRONT AND UPPER LEVEL
TROUGH PASS TUESDAY AFTERNOON. MUCH COOLER AND DRIER AIR FOR
TUESDAY NIGHT AND WEDNESDAY AS SURFACE HIGH PRESSURE BUILDS
ACROSS REGION.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
MODEL GUIDANCE CONTINUES TO SUGGEST A PROLONGED PERIOD OF DRY
WEATHER...WITH TEMPERATURES CLOSE TO OR JUST BELOW SEASONAL
AVERAGES INTO LATE WEEK.

&&

.AVIATION /22Z SUNDAY THROUGH FRIDAY/...
CONDITIONS WILL CONTINUE TO BOUNCE AROUND HIGH END MVFR/LOW END VFR
THIS AFTERNOON AS CONVECTION DEVELOPS WITH SURFACE HEATING AND
DESTABILIZATION. SHOWERS AND THUNDERSTORMS ARE ALREADY EXPANDING
ACROSS CENTRAL OHIO AND WEST VIRGINIA EARLY THIS AFTERNOON AND WILL
LIKELY IMPACT AT LEAST ZZV AND MGW PER THE LATEST HI RES GUIDANCE.
THUS...HAVE MENTIONED VCTS AT THOSE PORTS. WHILE SOME STORMS MAY
MAKE IT FURTHER NORTH AND EAST...THE LATEST HRRR TRIES TO KEEP THE
BULK OF STORMS SOUTH OF PIT SO GENERALLY MAINTAINED VCSH THIS
EVENING AS CONVECTION DIMINISHES WITH LOSS OF HEATING. ANY TAF THAT
IS IMPACTED BY A STORM THIS AFTERNOON AND EVENING WILL EXPERIENCE
BRIEF IFR CONDITIONS IN HEAVY RAIN BUT OPTED TO LEAVE THIS OUT OF
ANY PARTICULAR SITE FOR NOW.

THE UPPER RIDGE WILL BUILD OVERNIGHT...BUT DESPITE LIGHT WINDS
CONFIDENCE IN THE EXTENT OF FOG STRATUS THAT WOULD DEVELOP REMAINS
LOW. THUS...MAINTAINED GENERAL MVFR TOWARD SUNRISE WITH IMPROVEMENT
MONDAY MORNING.

.OUTLOOK.../MONDAY NIGHT THROUGH THURSDAY/...

PERIODIC CONVECTION AND RESULTING RESTRICTIONS ARE POSSIBLE UNTIL
PASSAGE OF A TUESDAY COLD FRONT.&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.

&&

$$




AREA FORECAST DISCUSSION

NWS PITTSBURGH PA

 256 PM EDT SUN MAY 17 2015

.SYNOPSIS...
WARM AND HUMID CONDITIONS WILL CONTINUE UNTIL PASSAGE OF A
TUESDAY COLD FRONT.

&&

.NEAR TERM /THROUGH MONDAY/...
WITH EXIT OF UPPER LEVEL WAVE SCATTERED DIURNAL CONVECTION HAS
DEVELOPED ACROSS MOST OF THE REGION AND WILL CONTINUE UNTIL AFTER
SUNSET. LEFT ISOLATED SHOWERS IN OVERNIGHT WITH HIGH DEW POINTS
AND DEEP MOISTURE...A STRAY SHOWER WILL BE POSSIBLE.

FOR MONDAY A PRE-FRONTAL TROUGH WILL MOVE INTO AND ACROSS THE
REGION WITH THE BEST OPPORTUNITY FOR WIDESPREAD SHOWERS AND
THUNDERSTORMS IN THE AFTERNOON. SPC HAS A MARGINAL THREAT OF
SEVERE...WITH PLENY OF LOW LEVEL INSTABILITY BUT UPPER LEVEL
SUPPORT LACKING. TEMPERATURES THROUGH MONDAY JUST A BIT ABOVE
MODEL MOS WITH HIGH DEW POINTS TONIGHT...AND POSSIBLY A BIT MORE
SUNSHINE MONDAY.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
AS PRE-FRONTAL TROUGH SHIFTS EAST MONDAY EVENING IT WILL TAKE MOST
OF THE DEEP MOISTURE WITH IT. POPS WILL BE IN THE CHANCE CATEGORY
AFTER MONDAY EVENING AS MAIN FRONT PUSHES EAST EARLY TUESDAY. DEW
POINTS WILL REMAIN A BIT ELEVATED UNTIL FRONT AND UPPER LEVEL
TROUGH PASS TUESDAY AFTERNOON. MUCH COOLER AND DRIER AIR FOR
TUESDAY NIGHT AND WEDNESDAY AS SURFACE HIGH PRESSURE BUILDS
ACROSS REGION.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
MODEL GUIDANCE CONTINUES TO SUGGEST A PROLONGED PERIOD OF DRY
WEATHER...WITH TEMPERATURES CLOSE TO OR JUST BELOW SEASONAL
AVERAGES INTO LATE WEEK.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
CONDITIONS WILL CONTINUE TO BOUNCE AROUND HIGH END MVFR/LOW END VFR
THIS AFTERNOON AS CONVECTION DEVELOPS WITH SURFACE HEATING AND
DESTABILIZATION. SHOWERS AND THUNDERSTORMS ARE ALREADY EXPANDING
ACROSS CENTRAL OHIO AND WEST VIRGINIA EARLY THIS AFTERNOON AND WILL
LIKELY IMPACT AT LEAST ZZV AND MGW PER THE LATEST HI RES GUIDANCE.
THUS...HAVE MENTIONED VCTS AT THOSE PORTS. WHILE SOME STORMS MAY
MAKE IT FURTHER NORTH AND EAST...THE LATEST HRRR TRIES TO KEEP THE
BULK OF STORMS SOUTH OF PIT SO GENERALLY MAINTAINED VCSH THIS
EVENING AS CONVECTION DIMINISHES WITH LOSS OF HEATING. ANY TAF THAT
IS IMPACTED BY A STORM THIS AFTERNOON AND EVENING WILL EXPERIENCE
BRIEF IFR CONDITIONS IN HEAVY RAIN BUT OPTED TO LEAVE THIS OUT OF
ANY PARTICULAR SITE FOR NOW.

THE UPPER RIDGE WILL BUILD OVERNIGHT...BUT DESPITE LIGHT WINDS
CONFIDENCE IN THE EXTENT OF FOG STRATUS THAT WOULD DEVELOP REMAINS
LOW. THUS...MAINTAINED GENERAL MVFR TOWARD SUNRISE WITH IMPROVEMENT
MONDAY MORNING.

.OUTLOOK.../MONDAY NIGHT THROUGH THURSDAY/...

PERIODIC CONVECTION AND RESULTING RESTRICTIONS ARE POSSIBLE UNTIL
PASSAGE OF A TUESDAY COLD FRONT.&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.

&&

$$



AREA FORECAST DISCUSSION

NWS MARQUETTE MI

 721 PM EDT MON MAY 18 2015

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 359 PM EDT MON MAY 18 2015

WV IMAGERY AND RAP ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH FROM
NW ONTARIO INTO THE WRN GREAT LAKES WITH THE LOW CIRCULATION CENTER
NEAR CYQT. AT THE SFC...A TROUGH EXTENDED THROUGH NRN LAKE SUPERIOR
FROM LOW PRES E OF LAKE SUPERIOR. WITH THE WRAP-AROUND MOISTURE/PCPN
MOVING EDGING TOWARD THE AREA...RADARS INDICATED DIURNALLY ENHANCED
SCT/NMRS -SHSN/SHRA FROM NE MN INTO NW WI. SOME LIGHT RAIN OR
DRIZZLE HAD ALSO DEVELOPED INTO UPSLOPE FLOW LOCATIONS OF NW UPPER
MI.

TONIGHT...THE COMBINATION OF DEEP MOISTURE SLIDING INTO THE AREA
BEHIND THE MID LEVEL LOW AND CAA DROPPING 850 MB TEMPS INTO THE -8C
TO -11C RANGE WILL SUPPORT SCT/NMRS -SHRA/-SHSN INTO MAINLY THE WEST
HALF OF UPPER MI. THE MOST FAVORABLE UPSLOPE FLOW AND LOW LEVEL CONV
WILL SHIFT TO LOCATIONS OVER THE W FAVORED BY NRLY FLOW AND INTO N
CNTRL UPPER MI LATE. LOW LEVEL THICKNESS AND WET-BULB ZERO HEIGHTS
SUGGEST ANY PCPN WILL CHANGE OVER TO MAINLY SNOW FROM WEST TO EAST
THIS EVENING. ALTHOUGH QPF AMOUNTS TO AROUND A TENTH OF AN INCH ARE
EXPECTED...WITH THE RELATIVELY WARM GROUND...ANY SNOWFALL AMOUNTS
SHOULD REMAIN AROUND A HALF INCH OR LESS...MAINLY ON GRASSY SURFACES.

TUE...AS HIGH PRES BUILDS TOWARD THE AREA WITH INCREASINGLY ACYC
LOW LEVEL FLOW...AND THE DEEPER MOISTURE DEPARTS TO THE EAST...THE
LINGERING SNOW SHOWERS SHOULD GRADUALLY DIMINISH AND END OVER MOST OF
THE CWA BY 18Z. THERE MAY BE SOME LIGHT PCPN LINGERING OVER THE EAST
DURING THE AFTERNOON. CLOUDS WILL ALSO ONLY SLOWLY DISSIPATE FROM
WEST TO EAST DURING THE MID TO LATE AFTERNOON.
OTHERWISE...UNSEASONABLY COLD CONDITIONS ARE EXPECTED WITH HIGHS
ONLY FROM AROUND 40 NORTH TO THE MID AND UPPER 40S SOUTH AND WEST.

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 320 PM EDT MON MAY 18 2015

A GENERALLY QUIET LONG TERM PERIOD IS IN STORE FOR THE UPPER GREAT
LAKES REGION. THIS IS DUE TO THE AREA LARGELY BEING BETWEEN AN
UPPER TROUGH OVER EASTERN CANADA AND ANOTHER OVER THE SOUTHWESTERN
CONUS. WHILE THE UPPER GREAT LAKES REGION WILL BE BRUSHED BY A FEW
WAVES ASSOCIATED WITH THESE FEATURES...THE OVERALL FLOW WILL BE OUT
OF THE NORTHWEST OR WEST-NORTHWEST WITH LIMITED MOISTURE.

HIGH PRESSURE BUILDS INTO THE AREA ON TUESDAY NIGHT AND REMAINS
INTO WEDNESDAY. THE DRY AIR ASSOCIATED WITH THE HIGH WILL DIMINISH
ANY LINGERING CLOUDS OVER THE EASTERN CWA QUICKLY DURING THE EARLY
EVENING HOURS. THE CLEARING SKIES AND WEAKENING WINDS WILL LEAD TO
A COLD NIGHT ACROSS THE AREA ON TUESDAY NIGHT. HAVE FOLLOWED THE
LOWER END OF GUIDANCE (WITH PWAT VALUES ONLY AROUND 0.25IN)...WHICH
GIVES VALUES IN THE 20S FOR MOST INTERIOR LOCATIONS. ALTHOUGH OUR
FROST/FREEZE PROGRAM HASN/T STARTED...WOULD EXPECT A WIDESPREAD
FROST (AND A HARD FREEZE FOR THE INTERIOR WEST) ACROSS UPPER
MICHIGAN AND PERSONS WITH SENSITIVE PLANTS WOULD BE WISE TO PREPARE
FOR A SOLID FROST.

A WEAK COLD FRONT DROPS SOUTH FROM ONTARIO WEDNESDAY NIGHT AND WITH
THE LACK OF MOISTURE ONLY SHOWED A PERIOD OF PARTLY CLOUDY SKIES
AS IT MOVES THROUGH. BEHIND THE FRONT...NORTHERLY FLOW OFF LAKE
SUPERIOR WILL KEEP TEMPERATURES COOLER NEAR LAKE SUPERIOR ON
THURSDAY (50S) WHILE AREAS INLAND RISE TO OR JUST ABOVE 60.
FRIDAY/SATURDAY CONTINUE TO LOOK DRY (WITH TEMPERATURES WARMING
TOWARDS NORMAL) AS ANOTHER CANADIAN HIGH PRESSURE MOVES ACROSS THE
AREA.

THE HIGH WILL DEPART SATURDAY NIGHT...AS ENERGY FROM THE
SOUTHWESTERN CONUS TROUGH EJECTS NORTHEAST TOWARDS THE AREA. A
SURFACE LOW DEVELOPING IN THE PLAINS WITH THIS FEATURE WILL MOVE
INTO IOWA BY SUNDAY NIGHT BEFORE SLOWLY SHIFTING EAST THROUGH
SOUTHERN WISCONSIN BY MONDAY NIGHT. AT THIS POINT...EXPECT THE CWA
TO BE ON THE NORTHERN EDGE OF MUCH OF THE FORCING (WARM FRONT
STALLS OVER SOUTHERN WISCONSIN) AND BEST CHANCES FOR RAIN WILL BE
OVER THE SOUTHERN HALF OF THE CWA AS WEAK SHORTWAVES LIFT NORTHEAST
ACROSS THE AREA IN THE SOUTHWESTERLY FLOW.
&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 720 PM EDT MON MAY 18 2015

WRAPAROUND MOISTURE WILL CONTINUE TO AFFECT ALL SITES OVERNIGHT WITH
LIFR CONDITIONS EXPECTED. NOT CONVINCED THAT PCPN WILL BE ALL SNOW
UNTIL LATER TONIGHT AND STARTED WITH RAIN...THEN A RAIN/SNOW MIX AND
THEN SNOW LATE TONIGHT. CONDITIONS WILL SLOWLY IMPROVE LATE TONIGHT
AS DRIER AIR WORKS IN AND SHOULD GO TO MVFR. VFR CONDITIONS WITH
MUCH DRIER AIR AND MIXING MOVE INTO CMX AND IWD TUE AFTERNOON.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 359 PM EDT MON MAY 18 2015

LOW PRES EAST OF LAKE SUPERIOR WILL CONTINUE TO MOVE TO THE EAST
TONIGHT. A TIGHTENING PRES GRADIENT AHEAD OF HIGH PRES BUILDING
TOWARD THE AREA FROM THE NRN PLAINS WILL BOOST NNW WINDS TO 20 TO 30
KNOTS WITH THE POTENTIAL FOR A FEW GALE FORCE GUSTS OVER THE E HALF
LATE TONIGHT AND TUE MORNING. WINDS WILL DIMINISH W TO E TUE
AFTERNOON/NIGHT THE HIGH BUILDS IN FM THE WEST. WED THRROUGH
SAT...WINDS WILL BE UNDER 20KT.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...JLB
LONG TERM...SRF
AVIATION...07
MARINE...JLB




AREA FORECAST DISCUSSION

NWS GRAND RAPIDS MI

 328 PM EDT SUN MAY 17 2015

LATEST UPDATE...
SYNOPSIS/SHORT TERM/LONG TERM/MARINE

.SYNOPSIS...
ISSUED AT 326 PM EDT SUN MAY 17 2015

A STRONG STORM FOR THIS TIME OF YEAR WILL TRACK TOWARD WESTERN
LAKE SUPERIOR BY MONDAY MORNING AND THEN INTO CENTRAL ONTARIO BY
TUESDAY MORNING. THAT WILL CAUSE A STRONG COLD FRONT TO COME
THROUGH THIS AREA MONDAY AFTERNOON. SCATTERED SHOWER AND
THUNDERSTORMS ARE EXPECTED EARLY TONIGHT WELL AHEAD OF THE COLD
FRONT. THEN IT WILL TURN BREEZY AND MUCH COLDER MONDAY NIGHT AND
TUESDAY. HIGHS WILLS STRUGGLE TO MAKE 50 TUESDAY AND THERE COULD
BE A FROST AND FREEZING TEMPERATURES BY WEDNESDAY MORNING.

&&

.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 326 PM EDT SUN MAY 17 2015

I CONTINUE TO BELIEVE THE RISK FOR STRONG TO SEVERE STORMS IS
RATHER LIMITED TONIGHT. THE BEST DYNAMICS ARE TO OUR WEST AND
NORTH...CLOSER TO THE SYSTEM OVER MINNESOTA AND WISCONSIN. THE
LATEST RUN OF THE RAP MODEL (18Z) CONTINUES TO SHOW THE LOW LEVEL
JET CORE TRACKING THROUGH WESTERN WISCONSIN THIS EVENING LEAVING
SOUTHWEST MICHIGAN IN THE SPEED  AREA BEHIND THAT JET. ALSO THE
BEST UPPER DIVERGENCE ASSOICATED WITH THE POLAR JET CORE IS EASILYOVER
WISCONSIN. WHILE THERE IS A SIGIFNCIANT AMOUNT OF MIXED LAYER CAPE
THIS EVENING THE LACK OF DYNAMICS WILL RESULT IN THE BEST STORMS
STAYING OVER WISCONSIN. EVEN SO SOME SHOWERS AND THUNDERSTORMS WILL
TRACK THROUGH OUR EASTERN CWA LATE THIS AFTERNOON THEN ANOTHER
AREA WILL TRACK THROUGH OUR CENTRAL AND EASTER COUNTIES AFTER 8PM
BUT I DO NOT EXPECT ANY SEVERE STORMS AT THIS TIME.

DRY AIR MOVES IN MONDAY THEN MUCH COLDER AIR MOVES IN BEHIND THE
SYSTEM FOR MONDAY NIGHT INTO TUESDAY NIGHT. THERE IS NOT ENOUGH
MOISTURE FOR SHOWERS IN THE COLD AIR MONDAY NIGHT OR TUESDAY. WE
MAY WILL HAVE FREEZING TEMPEATURES AND WIDESPEAD FROST TUESDAY
NIGHT AS SKIES CLEAR.



.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 326 PM EDT SUN MAY 17 2015

MUCH OF THE EXTENDED PERIOD WILL BE COOL AND DRY...BUT WE SHOULD SEE
A WARM UP BY THE WEEKEND...ALONG WITH A CHANCE OF SHOWERS AND STORMS
RETURNING SATURDAY NIGHT AND SUNDAY.

AN UPPER LOW OVER JAMES BAY WILL KEEP US COOL WITH A NORTHWEST UPPER
FLOW.  H8 TEMPS WED THROUGH FRI REMAIN IN THE +1 TO +4C RANGE...
KEEPING DAYTIME HIGH TEMPS BELOW NORMAL...MAINLY IN THE LOW AND MID
60S.  THERE SHOULD BE A BACK DOOR COLD FRONT COME THROUGH THURSDAY
NIGHT...BUT IT APPEARS DRY...JUST SUPPLYING A EXTRA SHOT OF COOL AIR
INTO FRIDAY.

A WARM UP SHOULD COMMENCE SATURDAY AS AN UPPER RIDGE BEGINS TO
BUBBLE TOWARD THE AREA PUSHING THE NW FLOW EAST.  TEMPS SHOULD
RETURN TO NEAR NORMAL VALUES.  RAIN CHANCES WILL RETURN SATURDAY
NIGHT OR SUNDAY AS A WARM FRONT LIFTS NORTH ACROSS IN/OH.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 148 PM EDT SUN MAY 17 2015

A MIX OF VFR AND MVFR CEILINGS WERE OVER THE REGION AS OF 17Z.
THIS IS EXPECTED TO TREND TO MORE VFR AS CEILINGS GRADUALLY LIFT
THIS AFTERNOON. FOR THE MOST PART VFR CONDITIONS WILL PREVAIL
THEREAFTER INTO MID DAY MONDAY.

INSTABILITY AND MOISTURE WAS INCREASING ACROSS THE AREA AND
SHOWERS AND THUNDERSTORMS SHOULD BEGIN TO DEVELOP AFTER 20Z.
STORMS SHOULD REMAIN SCATTERED ACROSS THE AREA THROUGH ABOUT 09Z
TONIGHT WHEN DRIER AIR ARRIVES. A COLD FRONT WILL PASS THROUGH SW
MI MONDAY AFTERNOON BUT AT THIS POINT IS APPEAR IT WILL PASS
THROUGH MAINLY DRY AS THE DEEPEST MOISTURE RACES EAST...WELL AHEAD
OF IT. LEFT ANY MENTION OF SHOWERS/STORMS OUT OF THE TAFS AFTER
09Z.

SOUTHERLY WINDS WILL GUST TO AROUND 20 KNOTS THROUGH THIS
EVENING...THEN BECOMING SOUTHWEST LATE TONIGHT AT 10-15 KTS.


&&

.MARINE...
ISSUED AT 326 PM EDT SUN MAY 17 2015

I CONTINUED THE FOG ADVIOSRY AS WEB CAMS DO SHOW SOME FOG YET.
WE WILL LIKELY NEED A SMALL CRAFT ADVISORY MONDAY NIGHT AND
TUESDAY AS THE COLD AIR COMES IN.

&&

.HYDROLOGY...
ISSUED AT 1210 AM EDT SUN MAY 17 2015

THE MAIN THREAT THROUGH THE NEXT 24 HOURS WILL BE THE POSSIBILITY
FOR LOCALIZED HEAVY RAINFALL.

A MAJORITY OF THE AREA STREAMS AND RIVERS ARE RUNNING WELL BELOW
ADVISORY LEVELS WITH A COUPLE OF SITES SLIGHTLY BELOW. SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO DEVELOP AND TRAVEL EAST OUT OF THE
UPPER MIDWEST THIS EVENING AND INTO TONIGHT. AREA AVERAGE
RAINFALL MAY RUN FROM A FEW TENTHS OF AN INCH UPWARDS OF A HALF
INCH. LOCALIZED HEAVY POCKETS WILL CREATE GREAT VARIATIONS IN
RAINFALL TOTALS IN SHORT DISTANCES. LOCATIONS THAT ARE AFFECTED BY
HEAVIER RAINFALL MAY EXPERIENCE LOCALIZED PONDING OR TEMPORARY
STREET FLOODING WITH SMALL CREEK AND STREAM FLUCTUATIONS
POSSIBLE. LARGER RIVERS ARE EXPECTED TO REMAIN BELOW ACTION
STAGE THROUGH THE PERIOD AS FEEDBACK TIMES WILL TAKE US INTO
DRIER WEATHER FOR THE UPCOMING WEEK.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...DENSE FOG ADVISORY UNTIL 8 AM EDT MONDAY FOR LMZ844>849.

&&

$$

SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...JK
AVIATION...JK
HYDROLOGY...JAM
MARINE...WDM



AREA FORECAST DISCUSSION

NWS GRAND RAPIDS MI

 148 PM EDT SUN MAY 17 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 315 AM EDT SUN MAY 17 2015

A WARM FRONT WILL LIFT NORTH TODAY PUTTING SOUTHERN LOWER MICHIGAN
IN AN INCREASINGLY WARM AND HUMID AIRMASS. AN ISOLATED SHOWER OR
STORM IS POSSIBLE TODAY WITH A MUCH BETTER CHANCE FOR SHOWERS AND
THUNDERSTORMS LATE THIS AFTERNOON AND EVENING. A STRONG COLD
FRONT WILL MOVE THROUGH MONDAY BRINGING A CONTINUED CHANCE FOR A
SHOWER OR THUNDERSTORM. MUCH COOLER WEATHER WILL MOVE IN TUESDAY
THROUGH MIDWEEK.

&&

.UPDATE...
ISSUED AT 1129 AM EDT SUN MAY 17 2015

I CURRENTLY REMAIN UNIMPRESSED ON THE CHANCE OF SEVERE STORMS
LATE THIS AFTERNOON AND THIS EVENING. THE RAP AND NAM FROM THE
LATEST MODEL RUNS HAVE TO CORE OF THE LOW LEVEL JET GOING OVER
NORTHERN LAKE MICHIGAN INTO THE UPPER PENINSULA BETWEEN 4 PM AND
MIDNIGHT. THAT PUTS SOUTHWEST MICHIGAN IN THE SPEED DIVERGENCE
AREA OF THE LOW LEVEL JET (NOT GOOD FOR SEVERE STORMS). THE UPPER
DIVERGENCE FROM THE UPPER LEVEL JET CORE IS OVER THE LOW LEVEL
JET MAX (NORTHERN WISCONSIN) THIS AFTERNOON AND EVENING...NOT
OVER SOUTHWEST MICHIGAN. THE DEEP LAYER SHEAR GREATER THAN 35
KNOTS IS MOSTLY WEST OF US-131 AND NORTH OF MKG THIS AFTERNOON AND
EVENING...REALLY IT IS OVER WISCONSIN (40 TO 60 KNOTS). THE SPC
ENSEMBLE 09Z HAS THE 30 TO 40 PERCENT CHANCE FOR SEVERE STORMS
OVER WISCONSIN THIS AFTERNOON AND EVENING...MEANWHILE A 10 PERCENT
AREA DOES GET INTO WESTERN LOWER MICHIGAN WEST OF US-131 FROM 4 PM
TILL 8 PM. ALL OF THIS TELL ME THE RISK FOR SEVERE STORMS OVER
SOUTHWEST MICHIGAN WOULD BE VERY LOW. STILL IT IS NOT ZERO SO WE
WILL HAVE TO WATCH AS CONDITIONS DEVELOP THIS AFTERNOON AND
EVENING.

OVERALL OUR BEST CHANCE FOR THUNDERSTORMS IS THIS EVENING. I HAVE
NOT SIGNIFICANTLY CHANGED OUR FORECAST IN THAT WAY.

&&

.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 315 AM EDT SUN MAY 17 2015

OUR PRIMARY SHORT TERM FCST CHALLENGE IS TO DETERMINE
PROBABILITIES FOR CONVECTION TODAY THROUGH MONDAY.

THE AIRMASS OVER OUR FCST AREA WILL BECOME INCREASINGLY WARM AND
HUMID TODAY AS A WARM FRONT GRADUALLY MOVES NORTH OF OUR AREA.
THERE IS JUST A SMALL CHANCE OF AN ISOLATED SHOWER OR THUNDERSTORM
BUT MOST OF OUR AREA WILL STAY DRY THIS MORNING THROUGH MOST OF
THE AFTERNOON.

00Z 4KM WRF-NMM SIM Z GUIDANCE AND THE NSSL WRF SUGGEST THAT
SHOWERS AND THUNDERSTORMS ARE LIKELY TO DEVELOP ACROSS OUR AREA
LATE THIS AFTERNOON THROUGH THE EVENING. CONVECTIVE DEVELOPMENT LATE
THIS AFTERNOON AND EARLY EVENING WILL BE AIDED BY WEAK TO MODERATE
INSTABILITY WITH POTENTIAL FOR SB CAPE VALUES TO REACH AROUND
1000-2000 J/KG.

SHOWERS AND STORMS LATE THIS EVENING WILL BE AIDED BY FORCING
FROM A 35 TO 40 KT LLJ AND STRONG 1000-850 MB MOISTURE TRANSPORT.
A FEW SHOWERS OR ISOLATED STORMS MAY LINGER VERY LATE TONIGHT BUT
THE MOST LIKELY TIME FRAME FOR CONVECTION SEEMS TO BE FROM AROUND
21Z THIS AFTERNOON THROUGH 06Z TONIGHT.

CONVECTIVE POTENTIAL FOR MONDAY IS LARGELY CONTINGENT ON EXACT
COLD FRONTAL TIMING. A CONSENSUS OF LATEST GUIDANCE SUGGESTS THAT
THE BETTER CHANCE FOR STORMS WILL LIKELY STAY SE OF OUR FCST
AREA... BUT THAT SOME SHOWERS AND STORMS MAY REDEVELOP MAINLY OVER
OUR SE FCST AREA PRIOR TO FROPA.

SHORT RANGE GUIDANCE CONTINUES TO SUGGEST SOME WEAK TO MODERATE
INSTABILITY WILL DEVELOP JUST AHEAD OF THE FRONT SO THIS WILL NEED
TO BE MONITORED SINCE FORCING FROM THE FRONT WILL BE STRONG.
HOWEVER IF FRONT MOVES THROUGH FASTER AS SUGGESTED BY THE 00Z GFS
THEN ALL OF OUR FCST AREA SHOULD STAY DRY MONDAY.

IT WILL TURN BREEZY BEHIND THE FRONT MONDAY NIGHT THROUGH TUESDAY
WITH STRONG NW FLOW CAA. MAX TEMPS TUESDAY WILL ONLY REACH THE
50S.

.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 315 AM EDT SUN MAY 17 2015

THREAT OF FROST EXISTS ON TUESDAY NIGHT AS COLD DRY AIR MASS SETTLES
INTO THE REGION FROM THE NORTH. HOWEVER THERE IS STILL SOME QUESTION
AS TO HOW QUICK THE SFC RIDGE BUILDS IN AND WHETHER OR NOT THE WINDS
DIE OFF. EXTENT OF CLEARING IS ALSO UNCERTAIN AT THIS TIME.

OTHERWISE A RATHER QUIET/UNEVENTFUL LONG TERM PERIOD EXPECTED WITH
SURFACE RIDGING AND RELATIVELY COOL DRY AIR MASS DOMINATING OUR
WEATHER. THIS PATTERN SHOULD RESULT IN A DECENT AMOUNT OF SUNSHINE
ALONG WITH LARGE DIURNAL TEMPERATURES SWINGS. EXPECT COOL NIGHTS AND
GENERALLY PLEASANT DAYS WITH LOW HUMIDITIES AND HIGHS MODERATING A
FEW DEGREES EACH DAY.

ONE THING TO WATCH HOWEVER IS THE POTENTIAL FOR CONSIDERABLE MID AND
HIGH CLOUDS AND EVEN SOME SPRINKLES ON WEDNESDAY RELATED TO A SYSTEM
PASSING BY JUST TO OUR SOUTH IN THE ZONAL FLOW. THEN...THE NORTHWEST
FLOW ALOFT ON THURSDAY AND FRIDAY COULD ALSO LEAD TO SOME BRIEF
PERIODS OF THICKER CLOUDS AND SPRINKLES AS WEAK FAST MOVING
SHORTWAVES OCCASIONALLY DROP THROUGH.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 148 PM EDT SUN MAY 17 2015

A MIX OF VFR AND MVFR CEILINGS WERE OVER THE REGION AS OF 17Z.
THIS IS EXPECTED TO TREND TO MORE VFR AS CEILINGS GRADUALLY LIFT
THIS AFTERNOON. FOR THE MOST PART VFR CONDITIONS WILL PREVAIL
THEREAFTER INTO MID DAY MONDAY.

INSTABILITY AND MOISTURE WAS INCREASING ACROSS THE AREA AND
SHOWERS AND THUNDERSTORMS SHOULD BEGIN TO DEVELOP AFTER 20Z.
STORMS SHOULD REMAIN SCATTERED ACROSS THE AREA THROUGH ABOUT 09Z
TONIGHT WHEN DRIER AIR ARRIVES. A COLD FRONT WILL PASS THROUGH SW
MI MONDAY AFTERNOON BUT AT THIS POINT IS APPEAR IT WILL PASS
THROUGH MAINLY DRY AS THE DEEPEST MOISTURE RACES EAST...WELL AHEAD
OF IT. LEFT ANY MENTION OF SHOWERS/STORMS OUT OF THE TAFS AFTER
09Z.

SOUTHERLY WINDS WILL GUST TO AROUND 20 KNOTS THROUGH THIS
EVENING...THEN BECOMING SOUTHWEST LATE TONIGHT AT 10-15 KTS.

&&

.MARINE...
ISSUED AT 315 AM EDT SUN MAY 17 2015

WE HAVE EXTENDED THE MARINE DENSE FOG ADVISORY THROUGH TONIGHT
SINCE A VERY WARM AND HUMID AIRMASS WILL CONTINUE TO ADVECT IN
OVER RELATIVELY COLD LAKE WATERS AND RESULT IN AREAS OF DENSE FOG.
SOUTHERLY WINDS WILL INCREASE SOMEWHAT THIS AFTERNOON THROUGH
TONIGHT RESULTING IN GRADUALLY INCREASING WAVE HEIGHTS. HOWEVER
WINDS AND WAVE HEIGHTS WILL STAY BELOW SMALL CRAFT CRITERIA
THROUGH TONIGHT. THUNDERSTORMS WILL POSE A HAZARD TO MARINERS LATE
THIS AFTERNOON AND EVENING.


&&

.HYDROLOGY...
ISSUED AT 1210 AM EDT SUN MAY 17 2015

THE MAIN THREAT THROUGH THE NEXT 24 HOURS WILL BE THE POSSIBILITY
FOR LOCALIZED HEAVY RAINFALL.

A MAJORITY OF THE AREA STREAMS AND RIVERS ARE RUNNING WELL BELOW
ADVISORY LEVELS WITH A COUPLE OF SITES SLIGHTLY BELOW. SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO DEVELOP AND TRAVEL EAST OUT OF THE
UPPER MIDWEST THIS EVENING AND INTO TONIGHT. AREA AVERAGE
RAINFALL MAY RUN FROM A FEW TENTHS OF AN INCH UPWARDS OF A HALF
INCH. LOCALIZED HEAVY POCKETS WILL CREATE GREAT VARIATIONS IN
RAINFALL TOTALS IN SHORT DISTANCES. LOCATIONS THAT ARE AFFECTED BY
HEAVIER RAINFALL MAY EXPERIENCE LOCALIZED PONDING OR TEMPORARY
STREET FLOODING WITH SMALL CREEK AND STREAM FLUCTUATIONS
POSSIBLE. LARGER RIVERS ARE EXPECTED TO REMAIN BELOW ACTION
STAGE THROUGH THE PERIOD AS FEEDBACK TIMES WILL TAKE US INTO
DRIER WEATHER FOR THE UPCOMING WEEK.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...DENSE FOG ADVISORY UNTIL 8 AM EDT MONDAY FOR LMZ844>849.

&&

$$

UPDATE...WDM
SYNOPSIS...LAURENS
SHORT TERM...LAURENS
LONG TERM...MEADE
AVIATION...JK
HYDROLOGY...JAM
MARINE...LAURENS



AREA FORECAST DISCUSSION

NWS DETROIT/PONTIAC MI

 1243 PM EDT SUN MAY 17 2015

.AVIATION...

EXPECT LOWER CLOUDS TO PERSIST BUT MIX OUT OF MVFR INTO LOW END VFR
DURING THE AFTERNOON. THIS WILL OCCUR UNDER A MORE UNIFORM SOUTH
WIND OVER THE TERMINAL CORRIDOR AS THE WARM FRONT PUSHES FARTHER
INTO NORTHERN LOWER MICHIGAN. THE POTENTIAL FOR SHOWERS WILL
INCREASE AS THE TEMPERATURE PUSHES 80 DURING THE LATE AFTERNOON
AND LASTING THROUGH THE EVENING. THE RAINFALL PATTERN WILL BE
ENHANCED TONIGHT BY A BROAD SWATH OF DEEPER MOISTURE MOVING IN ON
THE LEADING EDGE OF A STRONGER WAVE ALOFT. THIS DEEPER MOISTURE
WILL THEN MOVE EASTWARD BY SUNRISE. A STRONGER SOUTH WIND WILL
REDUCE THE FOG POTENTIAL MONDAY MORNING COMPARED TO THE LAST
COUPLE OF DAYS BUT IFR/MVFR CEILING IN STRATUS LOOKS LIKELY
INSTEAD.

FOR DTW... A SHOWER OR THUNDERSTORM COULD OCCUR NEAR THE LAKE ERIE
SHORELINE DURING THE LATE AFTERNOON. THIS WILL BE MONITORED BEFORE
INCLUSION IN THE FORECAST BEFORE A MORE LIKELY PERIOD OF SHOWERS
ARRIVES TONIGHT.

//DTW THRESHOLD PROBABILITIES...

* MEDIUM FOR CIG BELOW 5000 FEET TODAY AND TONIGHT.

* LOW FOR A THUNDERSTORM TODAY AND TONIGHT.

&&

.PREV DISCUSSION...ISSUED 1113 AM EDT SUN MAY 17 2015

UPDATE...

FOG LIFTED INTO LOW STRATUS DURING MID MORNING AND SOME OF THE
STRATUS MIXED OUT INTO POCKETS OF CLEAR SKY DURING LATE MORNING.
THE LATEST SATELLITE TREND INDICATES THE CLEAR POCKETS QUICKLY
FILLING IN WITH SHALLOW CU OVER THE MOIST BOUNDARY LAYER HAVING
DEWPOINT GENERALLY IN THE MID 60S. EXPECT THIS WILL CONTINUE WITH
NO BETTER THAN PARTLY SUNNY/BROKEN SKY THROUGH THE REST OF THE
DAY. THE MOIST BOUNDARY LAYER ALSO MAINTAINS A STAGE FOR SCATTERED
SHOWERS/ORDINARY STORMS AS CONDITIONS WARM TO CONVECTIVE
TEMPERATURE IN THE UPPER 70S. SURFACE ANALYSIS PLACES THE WARM
FRONT MOSTLY NORTH OF OUR AREA AND ATTEMPTING TO MAKE PROGRESS
INTO THE MID LAKE HURON MARINE LAYER. THERE COULD BE SOME
SHORELINE LAKE BREEZE BOUNDARIES TO FOCUS DEVELOPMENT LEAVING WARM
SECTOR SURFACE HEATING TO MAX TEMPS IN THE LOWER 80S NEEDED FOR
DEVELOPMENT ELSEWHERE. THE BEST CHANCE OF ACTIVITY WILL ACCOMPANY
THE PRIMARY THETA-E RIDGE BUILDING IN FROM ILLINOIS AND INDIANA
DURING LATE AFTERNOON INTO THIS EVENING.

PREV DISCUSSION...ISSUED 359 AM EDT SUN MAY 17 2015

SHORT TERM...TODAY AND TONIGHT

LIGHT WINDS...BREAKS IN THE CLOUDS...AND RAINFALL YESTERDAY HAVE ALL
SET THE STAGE FOR FOG AND STRATUS TO FORM ONCE AGAIN THIS MORNING.
SO FAR VISIBILITIES HAVE PREDOMINANTLY RANGED FROM 1-5 MILES. THE
ARRIVAL OF ADDITIONAL CLOUDS SHOULD HELP PREVENT WIDESPREAD DENSE
FOG...BUT PATCHES ARE CERTAINLY POSSIBLE. WILL CONTINUE TO MONITOR
DENSE FOG POTENTIAL THROUGH THE MORNING HOURS HOWEVER.

UPPER RIDGE STILL REMAINS OVER THE SOUTHEAST CONUS...WITH LOWER
MICHIGAN POSITIONED ON THE WESTERN PERIPHERY. THE RIDGE AXIS WILL
SHIFT EAST TODAY AS THE LARGE UPPER TROUGH OVER THE CENTRAL U.S.
BEGINS TO LIFT TOWARDS THE UPPER MIDWEST. THE INFLUENCE OF THE RIDGE
WILL CONTINUE TO PROVIDE A STABILIZING INFLUENCE OVER THE AREA
THROUGH THE MORNING HOURS...WITH THERMAL PROFILES ON GFS/NAM
FORECAST SOUNDINGS STILL SHOWING WEAK LAPSE RATES IN THE MID-LEVELS
ASSOCIATED WITH THE WARMER AIR ALOFT. POTENTIAL FOR CONVECTION
THROUGH THE EARLY PART OF THE DAY LOOKS LIMITED THEREFORE...BUT
STILL POSSIBLE ALONG A FEW FEATURES. FRONTAL BOUNDARY REMAINS DRAPED
ACROSS CENTRAL LOWER MICHIGAN AS OF 300 AM THIS MORNING. THIS FRONT
WILL LIFT NORTHWARD THROUGH THE LATE MORNING AS SOUTHERLY FLOW
INCREASES AHEAD OF THE APPROACHING UPPER TROUGH. THE FRONT COULD
PROVIDE A FOCUS THIS MORNING FOR A FEW SHOWERS OR EVEN A TSTORM TO
FORM OVER THE SAGINAW VALLEY AND THUMB. FURTHER SOUTH IN THE WARM
SECTOR...UPPER SHORTWAVE MOVING EAST THROUGH THE OHIO VALLEY COULD
TRIGGER A FEW SHOWERS/TSTORMS NEAR THE BORDER.

AIRMASS WILL REMAIN VERY MOIST TODAY/TONIGHT WITH DEWPOINTS IN THE
60S. TEMPERATURES IN THE MID-LEVELS WILL MEANWHILE COOL SLIGHTLY
THROUGH THE DAY AS THE UPPER RIDGE AXIS PULLS EAST...WHILE THE
SURFACE LAYER HEATS TO AROUND 80F THIS AFTERNOON. AS THIS
OCCURS...WILL SEE INSTABILITY INCREASE THROUGH THE DAY AND BECOME
SURFACE BASED...WITH A PARCEL OF 80/65 YIELDING ABOUT 1000 J/KG OF
CAPE DURING THE LATE AFTERNOON. SEVERE WEATHER IS NOT EXPECTED
THROUGH LATE AFTERNOON AS SHEAR VALUES LOOK UNIMPRESSIVE AND CAPE
LOOKS TALL/SKINNY. VERY HEAVY DOWNPOURS WILL CONTINUE TO BE POSSIBLE
AS PW VALUES RISE FROM 1.5 INCHES THIS MORNING TO AROUND 1.75 INCHES
TONIGHT. WILL NEED TO FIND A TRIGGER FOR CONVECTION IN THE WARM
SECTOR TODAY/TONIGHT IN ORDER TO GET ANYTHING OTHER THAN JUST A FEW
CELLS POPPING UP HOWEVER. LOOKING BACK AT OBSERVATIONAL AND MODEL
DATA OVER THE CONUS FROM YESTERDAY...IT APPEARS AN OLD WARM FRONT
WAS CAST OFF THE SYSTEM OVER THE SOUTHERN/CENTRAL PLAINS EARLY
YESTERDAY. CURRENT OBSERVATIONS OVER SOUTEHRN ILLINOIS/INDIANA DO
INDICATE A SLIGHT "KINK" IN THE FLOW. THIS IS WHERE NAM/GFS MODELS
CURRENTLY PLACE THIS FEATURE...AND THEY BOTH LIFT IT THROUGH
SOUTHEAST MICHIGAN BETWEEN 14-22Z (PER THERMAL FIELDS AND HIGHER
THETA-E ADVECTION). COVERAGE OF SHOWERS/TSTORMS THAT COULD DEVELOP
AS THIS SUBTLE FEATURE WORKS THROUGH IS UNCERTAIN HOWEVER AS THE
ATMOSPHERE REMAINS JUICY BUT NOT OVERLY BUOYANT. KEPT COVERAGE AT
CHANCE AS HIGHER-RES RUNS OF THE 4KM WRF AND THE HRRR DO NOT SEEM
TOO KEEN ON WIDESPREAD CONVECTION DEVELOPING UNDER THE MORE STABLE
INFLUENCE OF THE RIDGE DEPARTING TO OUR EAST.

WHILE THE MAIN COLD FRONT FROM THIS SYSTEM WILL NOT PUSH THROUGH THE
AREA UNTIL MONDAY NIGHT...WHAT IS LEFT OF THE WEAKENING FRONT NOW
EXTENDING FROM MINNESOTA DOWN INTO TEXAS WILL WORK EAST ACROSS LOWER
MICHIGAN TONIGHT. THIS SHOULD PROVIDE A BETTER FOCUS FOR
SHOWERS/TSTORMS. HIGHER RES RUNS CONTINUE TO SHOW THE CURRENT LINE
OF CONVECTION BREAKING...WITH MOST OF THE ACTIVITY LIFTING TO OUR
WEST AND NORTH...ONLY CLIPPING THE SAGINAW VALLEY. STILL...BETTER
INSTABILITY ARRIVING OVERNIGHT (ELEVATED) WARRANTS CHANCE-LIKELY
POPS AS IT WORKS THROUGH.

LONG TERM...MONDAY THROUGH SATURDAY

DEEP LAYER SOUTHWESTERLY FLOW FIRMLY IN PLACE ON MONDAY WITH THE
REGION STILL LARGELY OUTSIDE THE MAIN HEIGHT FALL CENTER AND
ASSOCIATED UPPER JET CORE ATTENDANT TO THE CLOSED LOW MEANDERING
ACROSS NORTHERN MN.  LEAD TROUGH AXIS TRANSLATING THROUGH TONIGHT
WILL SHUNT THE DEEPEST MOISTURE PLUME TO THE EAST BY MONDAY MORNING.
THE OVERALL REDUCTION IN MOISTURE QUALITY AND LACK OF AN APPARENT/
NECESSARY FORCING MECHANISM WITHIN THIS WELL MIXED WARM SECTOR
ENVIRONMENT WILL CONTAIN CONVECTIVE CHANCES PRIOR TO THE COLD
FRONTAL ARRIVAL.  ANY EARLY DAY LOW CLOUD DEBRIS WILL MIX OUT...
INCREASING THE LIKELIHOOD FOR SEEING A GOOD BIT OF SUN BY THE MIDDAY
PERIOD.   A SOLID LOOKING DIURNAL TEMPERATURE RESPONSE WITH HIGHS
MAKING A RUN INTO THE LOWER AND MIDDLE 80S.

COLD FRONTAL TIMING CENTERING ON THE 21Z-03Z PERIOD MONDAY
EVENING...AN ARRIVAL TIME CERTAINLY FAVORABLE TOWARD CAPITALIZING ON
THE BACK END OF PEAK HEATING.  EXISTING ENVIRONMENT LIKELY CARRYING
MLCAPE IN THE BALLPARK OF 1500 J/KG.  THIN RIBBON OF HIGHER THETA-E
ANCHORED ON THE BOUNDARY WILL HELP AUGMENT THIS DESTABILIZATION.
THE OVERALL FRONTAL POSITIONING AND TIMING WILL LEAVE A NARROW
WINDOW FOR CONVECTIVE INITIATION TO COMMENCE LOCALLY DURING THE
EVENING...ROUGHLY SOUTHEAST OF A HOWELL TO LAPEER LINE.  WHILE THE
STRONGER MID LEVEL WIND FIELD WILL RESIDE BEHIND THE FRONT...SOME
INCREASE IN DEEP LAYER SHEAR WILL OCCUR JUST AS THE FRONT ARRIVES.
MID LEVEL LAPSE RATES REMAIN MODEST...BUT GIVEN THE UNDERLYING LOW
LEVEL THERMODYNAMICS...POTENTIAL WILL EXIST FOR BETTER ORGANIZED
CELLS TO EMERGE WITH AN ACCOMPANYING ISOLATED SEVERE T-STORM RISK.

ENSUING POST-FRONTAL COLD AIR ADVECTION INCREASES HEADING INTO
TUESDAY...WITH 850 MB TEMPERATURES DROPPING A GOOD 15-20 DEGREES IN
24 HOURS.  THIS WILL LIKELY TRANSLATE INTO A BROAD STRATOCU FIELD
FOR TUESDAY...WITH TEMPERATURES STRUGGLING TO REACH MUCH ABOVE THE
60 DEGREE MARK.  DRY/STABLE PROFILE IN PLACE THROUGH THE MIDWEEK
PERIOD...CONDITIONS DEFINED BY LOW LEVEL ANTICYCLONIC FLOW TUCKED
BENEATH A WEAKLY CONFLUENT WEST-NORTHWEST MID LEVEL PATTERN.
SEASONABLY COOL AIR MASS LEFT TO RESPOND VIA A HIGHER DEGREE OF
INSOLATION ON WEDNESDAY...NO REAL ADVECTIVE COMPONENT IN PLACE.
SLOW MODERATION OF THIS ENVIRONMENT BY THURSDAY/FRIDAY AS UPPER
HEIGHTS START TO REBOUND.

MARINE...

FAVORABLE MARINE CONDITIONS IN TERMS OF WINDS AND WAVES TO FINISH
THE WEEKEND.  THE WARM AND INCREASINGLY HUMID CONDITIONS UNDER LIGHT
WIND WILL CONTINUE TO SUPPORT FOG OVER LAKE HURON THROUGH THE
MORNING HOURS.  A MARINE DENSE FOG ADVISORY REMAINS IN EFFECT SOUTH
OF SAGINAW BAY. THIS ENVIRONMENT WILL REMAIN FAVORABLE FOR THE
DEVELOPMENT OF SHOWERS AND THUNDERSTORMS THROUGH TONIGHT.  MODEST
SOUTHWESTERLY WINDS DEVELOP IN ADVANCE OF A COLD FRONT ON MONDAY.
COLD FRONT SWEEPS THROUGH MONDAY EVENING WITH COOLER AND DRIER
CONDITIONS DEVELOPING ON WEST TO NORTHWEST FLOW FOR THE MID WEEK
PERIOD.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...

MI...NONE.

LAKE HURON...DENSE FOG ADVISORY UNTIL 4 AM EDT MONDAY FOR LHZ421-422-441>443-
     462>464.

LAKE ST CLAIR...NONE.

MICHIGAN WATERS OF LAKE ERIE...NONE.

&&

$$

AVIATION.....BT
UPDATE.......BT
SHORT TERM...HLO
LONG TERM....MR
MARINE.......MR


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).



AREA FORECAST DISCUSSION

NWS GRAND RAPIDS MI

 1210 PM EDT SUN MAY 17 2015

LATEST UPDATE...
HYDRO

.SYNOPSIS...
ISSUED AT 315 AM EDT SUN MAY 17 2015

A WARM FRONT WILL LIFT NORTH TODAY PUTTING SOUTHERN LOWER MICHIGAN
IN AN INCREASINGLY WARM AND HUMID AIRMASS. AN ISOLATED SHOWER OR
STORM IS POSSIBLE TODAY WITH A MUCH BETTER CHANCE FOR SHOWERS AND
THUNDERSTORMS LATE THIS AFTERNOON AND EVENING. A STRONG COLD
FRONT WILL MOVE THROUGH MONDAY BRINGING A CONTINUED CHANCE FOR A
SHOWER OR THUNDERSTORM. MUCH COOLER WEATHER WILL MOVE IN TUESDAY
THROUGH MIDWEEK.

&&

.UPDATE...
ISSUED AT 1129 AM EDT SUN MAY 17 2015

I CURRENTLY REMAIN UNIMPRESSED ON THE CHANCE OF SEVERE STORMS
LATE THIS AFTERNOON AND THIS EVENING. THE RAP AND NAM FROM THE
LATEST MODEL RUNS HAVE TO CORE OF THE LOW LEVEL JET GOING OVER
NORTHERN LAKE MICHIGAN INTO THE UPPER PENINSULA BETWEEN 4 PM AND
MIDNIGHT. THAT PUTS SOUTHWEST MICHIGAN IN THE SPEED DIVERGENCE
AREA OF THE LOW LEVEL JET (NOT GOOD FOR SEVERE STORMS). THE UPPER
DIVERGENCE FROM THE UPPER LEVEL JET CORE IS OVER THE LOW LEVEL
JET MAX (NORTHERN WISCONSIN) THIS AFTERNOON AND EVENING...NOT
OVER SOUTHWEST MICHIGAN. THE DEEP LAYER SHEAR GREATER THAN 35
KNOTS IS MOSTLY WEST OF US-131 AND NORTH OF MKG THIS AFTERNOON AND
EVENING...REALLY IT IS OVER WISCONSIN (40 TO 60 KNOTS). THE SPC
ENSEMBLE 09Z HAS THE 30 TO 40 PERCENT CHANCE FOR SEVERE STORMS
OVER WISCONSIN THIS AFTERNOON AND EVENING...MEANWHILE A 10 PERCENT
AREA DOES GET INTO WESTERN LOWER MICHIGAN WEST OF US-131 FROM 4 PM
TILL 8 PM. ALL OF THIS TELL ME THE RISK FOR SEVERE STORMS OVER
SOUTHWEST MICHIGAN WOULD BE VERY LOW. STILL IT IS NOT ZERO SO WE
WILL HAVE TO WATCH AS CONDITIONS DEVELOP THIS AFTERNOON AND
EVENING.

OVERALL OUR BEST CHANCE FOR THUNDERSTORMS IS THIS EVENING. I HAVE
NOT SIGNIFICANTLY CHANGED OUR FORECAST IN THAT WAY.

&&

.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 315 AM EDT SUN MAY 17 2015

OUR PRIMARY SHORT TERM FCST CHALLENGE IS TO DETERMINE
PROBABILITIES FOR CONVECTION TODAY THROUGH MONDAY.

THE AIRMASS OVER OUR FCST AREA WILL BECOME INCREASINGLY WARM AND
HUMID TODAY AS A WARM FRONT GRADUALLY MOVES NORTH OF OUR AREA.
THERE IS JUST A SMALL CHANCE OF AN ISOLATED SHOWER OR THUNDERSTORM
BUT MOST OF OUR AREA WILL STAY DRY THIS MORNING THROUGH MOST OF
THE AFTERNOON.

00Z 4KM WRF-NMM SIM Z GUIDANCE AND THE NSSL WRF SUGGEST THAT
SHOWERS AND THUNDERSTORMS ARE LIKELY TO DEVELOP ACROSS OUR AREA
LATE THIS AFTERNOON THROUGH THE EVENING. CONVECTIVE DEVELOPMENT LATE
THIS AFTERNOON AND EARLY EVENING WILL BE AIDED BY WEAK TO MODERATE
INSTABILITY WITH POTENTIAL FOR SB CAPE VALUES TO REACH AROUND
1000-2000 J/KG.

SHOWERS AND STORMS LATE THIS EVENING WILL BE AIDED BY FORCING
FROM A 35 TO 40 KT LLJ AND STRONG 1000-850 MB MOISTURE TRANSPORT.
A FEW SHOWERS OR ISOLATED STORMS MAY LINGER VERY LATE TONIGHT BUT
THE MOST LIKELY TIME FRAME FOR CONVECTION SEEMS TO BE FROM AROUND
21Z THIS AFTERNOON THROUGH 06Z TONIGHT.

CONVECTIVE POTENTIAL FOR MONDAY IS LARGELY CONTINGENT ON EXACT
COLD FRONTAL TIMING. A CONSENSUS OF LATEST GUIDANCE SUGGESTS THAT
THE BETTER CHANCE FOR STORMS WILL LIKELY STAY SE OF OUR FCST
AREA... BUT THAT SOME SHOWERS AND STORMS MAY REDEVELOP MAINLY OVER
OUR SE FCST AREA PRIOR TO FROPA.

SHORT RANGE GUIDANCE CONTINUES TO SUGGEST SOME WEAK TO MODERATE
INSTABILITY WILL DEVELOP JUST AHEAD OF THE FRONT SO THIS WILL NEED
TO BE MONITORED SINCE FORCING FROM THE FRONT WILL BE STRONG.
HOWEVER IF FRONT MOVES THROUGH FASTER AS SUGGESTED BY THE 00Z GFS
THEN ALL OF OUR FCST AREA SHOULD STAY DRY MONDAY.

IT WILL TURN BREEZY BEHIND THE FRONT MONDAY NIGHT THROUGH TUESDAY
WITH STRONG NW FLOW CAA. MAX TEMPS TUESDAY WILL ONLY REACH THE
50S.

.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 315 AM EDT SUN MAY 17 2015

THREAT OF FROST EXISTS ON TUESDAY NIGHT AS COLD DRY AIR MASS SETTLES
INTO THE REGION FROM THE NORTH. HOWEVER THERE IS STILL SOME QUESTION
AS TO HOW QUICK THE SFC RIDGE BUILDS IN AND WHETHER OR NOT THE WINDS
DIE OFF. EXTENT OF CLEARING IS ALSO UNCERTAIN AT THIS TIME.

OTHERWISE A RATHER QUIET/UNEVENTFUL LONG TERM PERIOD EXPECTED WITH
SURFACE RIDGING AND RELATIVELY COOL DRY AIR MASS DOMINATING OUR
WEATHER. THIS PATTERN SHOULD RESULT IN A DECENT AMOUNT OF SUNSHINE
ALONG WITH LARGE DIURNAL TEMPERATURES SWINGS. EXPECT COOL NIGHTS AND
GENERALLY PLEASANT DAYS WITH LOW HUMIDITIES AND HIGHS MODERATING A
FEW DEGREES EACH DAY.

ONE THING TO WATCH HOWEVER IS THE POTENTIAL FOR CONSIDERABLE MID AND
HIGH CLOUDS AND EVEN SOME SPRINKLES ON WEDNESDAY RELATED TO A SYSTEM
PASSING BY JUST TO OUR SOUTH IN THE ZONAL FLOW. THEN...THE NORTHWEST
FLOW ALOFT ON THURSDAY AND FRIDAY COULD ALSO LEAD TO SOME BRIEF
PERIODS OF THICKER CLOUDS AND SPRINKLES AS WEAK FAST MOVING
SHORTWAVES OCCASIONALLY DROP THROUGH.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 757 AM EDT SUN MAY 17 2015

WIDESPREAD MVFR CONDITIONS ARE EXPECTED THROUGH MUCH OF TODAY
WITH LIGHT FOG/HAZE AND CIGS GENERALLY 1500-2500 FT. WHILE
SCATTERED SHOWERS ARE POSSIBLE ALL DAY TODAY...THE MAIN RISK OF
TSTMS SHOULD HOLD OFF UNTIL AFTER 21Z... POSSIBLY EVEN LATER...
LINGERING THROUGH ABOUT 04Z. CIGS LATER TODAY AND THIS EVENING MAY
BECOME PREDOMINATELY VFR...BUT WILL LIKELY TREND BACK DOWN TO MVFR
OR IFR AFTER 04Z TONIGHT. SFC WINDS WILL BE SOUTH AT 10 TO 20 KTS
TODAY AND TONIGHT.


&&

.MARINE...
ISSUED AT 315 AM EDT SUN MAY 17 2015

WE HAVE EXTENDED THE MARINE DENSE FOG ADVISORY THROUGH TONIGHT
SINCE A VERY WARM AND HUMID AIRMASS WILL CONTINUE TO ADVECT IN
OVER RELATIVELY COLD LAKE WATERS AND RESULT IN AREAS OF DENSE FOG.
SOUTHERLY WINDS WILL INCREASE SOMEWHAT THIS AFTERNOON THROUGH
TONIGHT RESULTING IN GRADUALLY INCREASING WAVE HEIGHTS. HOWEVER
WINDS AND WAVE HEIGHTS WILL STAY BELOW SMALL CRAFT CRITERIA
THROUGH TONIGHT. THUNDERSTORMS WILL POSE A HAZARD TO MARINERS LATE
THIS AFTERNOON AND EVENING.


&&

.HYDROLOGY...
ISSUED AT 1210 AM EDT SUN MAY 17 2015

THE MAIN THREAT THROUGH THE NEXT 24 HOURS WILL BE THE POSSIBILITY
FOR LOCALIZED HEAVY RAINFALL.

A MAJORITY OF THE AREA STREAMS AND RIVERS ARE RUNNING WELL BELOW
ADVISORY LEVELS WITH A COUPLE OF SITES SLIGHTLY BELOW. SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO DEVELOP AND TRAVEL EAST OUT OF THE
UPPER MIDWEST THIS EVENING AND INTO TONIGHT. AREA AVERAGE
RAINFALL MAY RUN FROM A FEW TENTHS OF AN INCH UPWARDS OF A HALF
INCH. LOCALIZED HEAVY POCKETS WILL CREATE GREAT VARIATIONS IN
RAINFALL TOTALS IN SHORT DISTANCES. LOCATIONS THAT ARE AFFECTED BY
HEAVIER RAINFALL MAY EXPERIENCE LOCALIZED PONDING OR TEMPORARY
STREET FLOODING WITH SMALL CREEK AND STREAM FLUCTUATIONS
POSSIBLE. LARGER RIVERS ARE EXPECTED TO REMAIN BELOW ACTION
STAGE THROUGH THE PERIOD AS FEEDBACK TIMES WILL TAKE US INTO
DRIER WEATHER FOR THE UPCOMING WEEK.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...DENSE FOG ADVISORY UNTIL 8 AM EDT MONDAY FOR LMZ844>849.

&&

$$

UPDATE...WDM
SYNOPSIS...LAURENS
SHORT TERM...LAURENS
LONG TERM...MEADE
AVIATION...MEADE
HYDROLOGY...JAM
MARINE...LAURENS




AREA FORECAST DISCUSSION

NWS GRAND RAPIDS MI

 1129 AM EDT SUN MAY 17 2015

LATEST UPDATE...
UPDATE

.SYNOPSIS...
ISSUED AT 315 AM EDT SUN MAY 17 2015

A WARM FRONT WILL LIFT NORTH TODAY PUTTING SOUTHERN LOWER MICHIGAN
IN AN INCREASINGLY WARM AND HUMID AIRMASS. AN ISOLATED SHOWER OR
STORM IS POSSIBLE TODAY WITH A MUCH BETTER CHANCE FOR SHOWERS AND
THUNDERSTORMS LATE THIS AFTERNOON AND EVENING. A STRONG COLD
FRONT WILL MOVE THROUGH MONDAY BRINGING A CONTINUED CHANCE FOR A
SHOWER OR THUNDERSTORM. MUCH COOLER WEATHER WILL MOVE IN TUESDAY
THROUGH MIDWEEK.

&&

.UPDATE...
ISSUED AT 1129 AM EDT SUN MAY 17 2015

I CURRENTLY REMAIN UNIMPRESSED ON THE CHANCE OF SEVERE STORMS
LATE THIS AFTERNOON AND THIS EVENING. THE RAP AND NAM FROM THE
LATEST MODEL RUNS HAVE TO CORE OF THE LOW LEVEL JET GOING OVER
NORTHERN LAKE MICHIGAN INTO THE UPPER PENINSULA BETWEEN 4 PM AND
MIDNIGHT. THAT PUTS SOUTHWEST MICHIGAN IN THE SPEED DIVERGENCE
AREA OF THE LOW LEVEL JET (NOT GOOD FOR SEVERE STORMS). THE UPPER
DIVERGENCE FROM THE UPPER LEVEL JET CORE IS OVER THE LOW LEVEL
JET MAX (NORTHERN WISCONSIN) THIS AFTERNOON AND EVENING...NOT
OVER SOUTHWEST MICHIGAN. THE DEEP LAYER SHEAR GREATER THAN 35
KNOTS IS MOSTLY WEST OF US-131 AND NORTH OF MKG THIS AFTERNOON AND
EVENING...REALLY IT IS OVER WISCONSIN (40 TO 60 KNOTS). THE SPC
ENSEMBLE 09Z HAS THE 30 TO 40 PERCENT CHANCE FOR SEVERE STORMS
OVER WISCONSIN THIS AFTERNOON AND EVENING...MEANWHILE A 10 PERCENT
AREA DOES GET INTO WESTERN LOWER MICHIGAN WEST OF US-131 FROM 4 PM
TILL 8 PM. ALL OF THIS TELL ME THE RISK FOR SEVERE STORMS OVER
SOUTHWEST MICHIGAN WOULD BE VERY LOW. STILL IT IS NOT ZERO SO WE
WILL HAVE TO WATCH AS CONDITIONS DEVELOP THIS AFTERNOON AND
EVENING.

OVERALL OUR BEST CHANCE FOR THUNDERSTORMS IS THIS EVENING. I HAVE
NOT SIGNIFICANTLY CHANGED OUR FORECAST IN THAT WAY.

&&

.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 315 AM EDT SUN MAY 17 2015

OUR PRIMARY SHORT TERM FCST CHALLENGE IS TO DETERMINE
PROBABILITIES FOR CONVECTION TODAY THROUGH MONDAY.

THE AIRMASS OVER OUR FCST AREA WILL BECOME INCREASINGLY WARM AND
HUMID TODAY AS A WARM FRONT GRADUALLY MOVES NORTH OF OUR AREA.
THERE IS JUST A SMALL CHANCE OF AN ISOLATED SHOWER OR THUNDERSTORM
BUT MOST OF OUR AREA WILL STAY DRY THIS MORNING THROUGH MOST OF
THE AFTERNOON.

00Z 4KM WRF-NMM SIM Z GUIDANCE AND THE NSSL WRF SUGGEST THAT
SHOWERS AND THUNDERSTORMS ARE LIKELY TO DEVELOP ACROSS OUR AREA
LATE THIS AFTERNOON THROUGH THE EVENING. CONVECTIVE DEVELOPMENT LATE
THIS AFTERNOON AND EARLY EVENING WILL BE AIDED BY WEAK TO MODERATE
INSTABILITY WITH POTENTIAL FOR SB CAPE VALUES TO REACH AROUND
1000-2000 J/KG.

SHOWERS AND STORMS LATE THIS EVENING WILL BE AIDED BY FORCING
FROM A 35 TO 40 KT LLJ AND STRONG 1000-850 MB MOISTURE TRANSPORT.
A FEW SHOWERS OR ISOLATED STORMS MAY LINGER VERY LATE TONIGHT BUT
THE MOST LIKELY TIME FRAME FOR CONVECTION SEEMS TO BE FROM AROUND
21Z THIS AFTERNOON THROUGH 06Z TONIGHT.

CONVECTIVE POTENTIAL FOR MONDAY IS LARGELY CONTINGENT ON EXACT
COLD FRONTAL TIMING. A CONSENSUS OF LATEST GUIDANCE SUGGESTS THAT
THE BETTER CHANCE FOR STORMS WILL LIKELY STAY SE OF OUR FCST
AREA... BUT THAT SOME SHOWERS AND STORMS MAY REDEVELOP MAINLY OVER
OUR SE FCST AREA PRIOR TO FROPA.

SHORT RANGE GUIDANCE CONTINUES TO SUGGEST SOME WEAK TO MODERATE
INSTABILITY WILL DEVELOP JUST AHEAD OF THE FRONT SO THIS WILL NEED
TO BE MONITORED SINCE FORCING FROM THE FRONT WILL BE STRONG.
HOWEVER IF FRONT MOVES THROUGH FASTER AS SUGGESTED BY THE 00Z GFS
THEN ALL OF OUR FCST AREA SHOULD STAY DRY MONDAY.

IT WILL TURN BREEZY BEHIND THE FRONT MONDAY NIGHT THROUGH TUESDAY
WITH STRONG NW FLOW CAA. MAX TEMPS TUESDAY WILL ONLY REACH THE
50S.

.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 315 AM EDT SUN MAY 17 2015

THREAT OF FROST EXISTS ON TUESDAY NIGHT AS COLD DRY AIR MASS SETTLES
INTO THE REGION FROM THE NORTH. HOWEVER THERE IS STILL SOME QUESTION
AS TO HOW QUICK THE SFC RIDGE BUILDS IN AND WHETHER OR NOT THE WINDS
DIE OFF. EXTENT OF CLEARING IS ALSO UNCERTAIN AT THIS TIME.

OTHERWISE A RATHER QUIET/UNEVENTFUL LONG TERM PERIOD EXPECTED WITH
SURFACE RIDGING AND RELATIVELY COOL DRY AIR MASS DOMINATING OUR
WEATHER. THIS PATTERN SHOULD RESULT IN A DECENT AMOUNT OF SUNSHINE
ALONG WITH LARGE DIURNAL TEMPERATURES SWINGS. EXPECT COOL NIGHTS AND
GENERALLY PLEASANT DAYS WITH LOW HUMIDITIES AND HIGHS MODERATING A
FEW DEGREES EACH DAY.

ONE THING TO WATCH HOWEVER IS THE POTENTIAL FOR CONSIDERABLE MID AND
HIGH CLOUDS AND EVEN SOME SPRINKLES ON WEDNESDAY RELATED TO A SYSTEM
PASSING BY JUST TO OUR SOUTH IN THE ZONAL FLOW. THEN...THE NORTHWEST
FLOW ALOFT ON THURSDAY AND FRIDAY COULD ALSO LEAD TO SOME BRIEF
PERIODS OF THICKER CLOUDS AND SPRINKLES AS WEAK FAST MOVING
SHORTWAVES OCCASIONALLY DROP THROUGH.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 757 AM EDT SUN MAY 17 2015

WIDESPREAD MVFR CONDITIONS ARE EXPECTED THROUGH MUCH OF TODAY
WITH LIGHT FOG/HAZE AND CIGS GENERALLY 1500-2500 FT. WHILE
SCATTERED SHOWERS ARE POSSIBLE ALL DAY TODAY...THE MAIN RISK OF
TSTMS SHOULD HOLD OFF UNTIL AFTER 21Z... POSSIBLY EVEN LATER...
LINGERING THROUGH ABOUT 04Z. CIGS LATER TODAY AND THIS EVENING MAY
BECOME PREDOMINATELY VFR...BUT WILL LIKELY TREND BACK DOWN TO MVFR
OR IFR AFTER 04Z TONIGHT. SFC WINDS WILL BE SOUTH AT 10 TO 20 KTS
TODAY AND TONIGHT.


&&

.MARINE...
ISSUED AT 315 AM EDT SUN MAY 17 2015

WE HAVE EXTENDED THE MARINE DENSE FOG ADVISORY THROUGH TONIGHT
SINCE A VERY WARM AND HUMID AIRMASS WILL CONTINUE TO ADVECT IN
OVER RELATIVELY COLD LAKE WATERS AND RESULT IN AREAS OF DENSE FOG.
SOUTHERLY WINDS WILL INCREASE SOMEWHAT THIS AFTERNOON THROUGH
TONIGHT RESULTING IN GRADUALLY INCREASING WAVE HEIGHTS. HOWEVER
WINDS AND WAVE HEIGHTS WILL STAY BELOW SMALL CRAFT CRITERIA
THROUGH TONIGHT. THUNDERSTORMS WILL POSE A HAZARD TO MARINERS LATE
THIS AFTERNOON AND EVENING.


&&

.HYDROLOGY...
ISSUED AT 147 PM EDT SAT MAY 16 2015

RIVER LEVELS ARE FLUCTUATING SLIGHTLY FROM THE RAIN ON FRIDAY... AND
ARE RUNNING NEAR TO BELOW NORMAL IN SOUTHERN MICHIGAN AND ABOVE
NORMAL IN WESTERN AND CENTRAL MICHIGAN. SCATTERED THUNDERSTORMS
SUNDAY AND MONDAY COULD LEAD TO LOCALLY HEAVY RAINFALL... BUT BASIN
AVERAGE RAINFALL OF A TENTH TO QUARTER INCH OVER THE NEXT COUPLE
DAYS WILL KEEP LARGER RIVER SYSTEM LEVELS UNDER CONTROL.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...DENSE FOG ADVISORY UNTIL 8 AM EDT MONDAY FOR LMZ844>849.

&&

$$

UPDATE...WDM
SYNOPSIS...LAURENS
SHORT TERM...LAURENS
LONG TERM...MEADE
AVIATION...MEADE
HYDROLOGY...CAS
MARINE...LAURENS



AREA FORECAST DISCUSSION

NWS DETROIT/PONTIAC MI

 1113 AM EDT SUN MAY 17 2015

.UPDATE...

FOG LIFTED INTO LOW STRATUS DURING MID MORNING AND SOME OF THE
STRATUS MIXED OUT INTO POCKETS OF CLEAR SKY DURING LATE MORNING.
THE LATEST SATELLITE TREND INDICATES THE CLEAR POCKETS QUICKLY
FILLING IN WITH SHALLOW CU OVER THE MOIST BOUNDARY LAYER HAVING
DEWPOINT GENERALLY IN THE MID 60S. EXPECT THIS WILL CONTINUE WITH
NO BETTER THAN PARTLY SUNNY/BROKEN SKY THROUGH THE REST OF THE
DAY. THE MOIST BOUNDARY LAYER ALSO MAINTAINS A STAGE FOR SCATTERED
SHOWERS/ORDINARY STORMS AS CONDITIONS WARM TO CONVECTIVE
TEMPERATURE IN THE UPPER 70S. SURFACE ANALYSIS PLACES THE WARM
FRONT MOSTLY NORTH OF OUR AREA AND ATTEMPTING TO MAKE PROGRESS
INTO THE MID LAKE HURON MARINE LAYER. THERE COULD BE SOME
SHORELINE LAKE BREEZE BOUNDARIES TO FOCUS DEVELOPMENT LEAVING WARM
SECTOR SURFACE HEATING TO MAX TEMPS IN THE LOWER 80S NEEDED FOR
DEVELOPMENT ELSEWHERE. THE BEST CHANCE OF ACTIVITY WILL ACCOMPANY
THE PRIMARY THETA-E RIDGE BUILDING IN FROM ILLINOIS AND INDIANA
DURING LATE AFTERNOON INTO THIS EVENING.

&&

.AVIATION...ISSUED 732 AM EDT SUN MAY 17 2015

LOW CLOUDS AND FOG WILL QUICKLY LIFT BETWEEN 12-16Z THIS
MORNING...RESULTING IN HIGH-END MVFR CONDITIONS BY LATE MORNING. A
WARM AND MOIST AIRMASS WILL AGAIN BRING THE THREAT FOR SHOWERS AND
THUNDERSTORMS TODAY...HOWEVER COVERAGE AND TIMING ARE VERY UNCERTAIN
WITH A LACK OF STRONG FOCUSING MECHANISM AND ONLY WEAK INSTABILITY.
A BETTER CHANCE FOR SHOWERS AND THUNDERSTORMS WILL THEN EXIST
OVERNIGHT...ESPECIALLY FROM FNT NORTH...AS THE REMNANTS OF A COLD
FRONT MOVE ACROSS THE AREA.

FOR DTW...FOG AND LOW CEILINGS WILL LIFT THROUGH THE MORNING AS
SOUTH-SOUTHEAST WINDS BEGIN TO INCREASE. SHOWERS AND THUNDERSTORMS
WILL BE POSSIBLE TODAY...HOWEVER TIMING AND COVERAGE ARE TOO
UNCERTAIN AT THIS TIME TO HIGHLIGHT IN TAFS.

//DTW THRESHOLD PROBABILITIES...

* MEDIUM FOR CIG BELOW 5000 FEET THROUGH 00Z.

* LOW FOR A THUNDERSTORM TODAY AND TONIGHT.

* LOW FOR VISIBILITY BELOW 1/2SM AND CIGS BELOW 200 FEET AFTER 12Z
  THIS MORNING.

&&

.PREV DISCUSSION...ISSUED 359 AM EDT SUN MAY 17 2015

SHORT TERM...TODAY AND TONIGHT

LIGHT WINDS...BREAKS IN THE CLOUDS...AND RAINFALL YESTERDAY HAVE ALL
SET THE STAGE FOR FOG AND STRATUS TO FORM ONCE AGAIN THIS MORNING.
SO FAR VISIBILITIES HAVE PREDOMINANTLY RANGED FROM 1-5 MILES. THE
ARRIVAL OF ADDITIONAL CLOUDS SHOULD HELP PREVENT WIDESPREAD DENSE
FOG...BUT PATCHES ARE CERTAINLY POSSIBLE. WILL CONTINUE TO MONITOR
DENSE FOG POTENTIAL THROUGH THE MORNING HOURS HOWEVER.

UPPER RIDGE STILL REMAINS OVER THE SOUTHEAST CONUS...WITH LOWER
MICHIGAN POSITIONED ON THE WESTERN PERIPHERY. THE RIDGE AXIS WILL
SHIFT EAST TODAY AS THE LARGE UPPER TROUGH OVER THE CENTRAL U.S.
BEGINS TO LIFT TOWARDS THE UPPER MIDWEST. THE INFLUENCE OF THE RIDGE
WILL CONTINUE TO PROVIDE A STABILIZING INFLUENCE OVER THE AREA
THROUGH THE MORNING HOURS...WITH THERMAL PROFILES ON GFS/NAM
FORECAST SOUNDINGS STILL SHOWING WEAK LAPSE RATES IN THE MID-LEVELS
ASSOCIATED WITH THE WARMER AIR ALOFT. POTENTIAL FOR CONVECTION
THROUGH THE EARLY PART OF THE DAY LOOKS LIMITED THEREFORE...BUT
STILL POSSIBLE ALONG A FEW FEATURES. FRONTAL BOUNDARY REMAINS DRAPED
ACROSS CENTRAL LOWER MICHIGAN AS OF 300 AM THIS MORNING. THIS FRONT
WILL LIFT NORTHWARD THROUGH THE LATE MORNING AS SOUTHERLY FLOW
INCREASES AHEAD OF THE APPROACHING UPPER TROUGH. THE FRONT COULD
PROVIDE A FOCUS THIS MORNING FOR A FEW SHOWERS OR EVEN A TSTORM TO
FORM OVER THE SAGINAW VALLEY AND THUMB. FURTHER SOUTH IN THE WARM
SECTOR...UPPER SHORTWAVE MOVING EAST THROUGH THE OHIO VALLEY COULD
TRIGGER A FEW SHOWERS/TSTORMS NEAR THE BORDER.

AIRMASS WILL REMAIN VERY MOIST TODAY/TONIGHT WITH DEWPOINTS IN THE
60S. TEMPERATURES IN THE MID-LEVELS WILL MEANWHILE COOL SLIGHTLY
THROUGH THE DAY AS THE UPPER RIDGE AXIS PULLS EAST...WHILE THE
SURFACE LAYER HEATS TO AROUND 80F THIS AFTERNOON. AS THIS
OCCURS...WILL SEE INSTABILITY INCREASE THROUGH THE DAY AND BECOME
SURFACE BASED...WITH A PARCEL OF 80/65 YIELDING ABOUT 1000 J/KG OF
CAPE DURING THE LATE AFTERNOON. SEVERE WEATHER IS NOT EXPECTED
THROUGH LATE AFTERNOON AS SHEAR VALUES LOOK UNIMPRESSIVE AND CAPE
LOOKS TALL/SKINNY. VERY HEAVY DOWNPOURS WILL CONTINUE TO BE POSSIBLE
AS PW VALUES RISE FROM 1.5 INCHES THIS MORNING TO AROUND 1.75 INCHES
TONIGHT. WILL NEED TO FIND A TRIGGER FOR CONVECTION IN THE WARM
SECTOR TODAY/TONIGHT IN ORDER TO GET ANYTHING OTHER THAN JUST A FEW
CELLS POPPING UP HOWEVER. LOOKING BACK AT OBSERVATIONAL AND MODEL
DATA OVER THE CONUS FROM YESTERDAY...IT APPEARS AN OLD WARM FRONT
WAS CAST OFF THE SYSTEM OVER THE SOUTHERN/CENTRAL PLAINS EARLY
YESTERDAY. CURRENT OBSERVATIONS OVER SOUTEHRN ILLINOIS/INDIANA DO
INDICATE A SLIGHT "KINK" IN THE FLOW. THIS IS WHERE NAM/GFS MODELS
CURRENTLY PLACE THIS FEATURE...AND THEY BOTH LIFT IT THROUGH
SOUTHEAST MICHIGAN BETWEEN 14-22Z (PER THERMAL FIELDS AND HIGHER
THETA-E ADVECTION). COVERAGE OF SHOWERS/TSTORMS THAT COULD DEVELOP
AS THIS SUBTLE FEATURE WORKS THROUGH IS UNCERTAIN HOWEVER AS THE
ATMOSPHERE REMAINS JUICY BUT NOT OVERLY BUOYANT. KEPT COVERAGE AT
CHANCE AS HIGHER-RES RUNS OF THE 4KM WRF AND THE HRRR DO NOT SEEM
TOO KEEN ON WIDESPREAD CONVECTION DEVELOPING UNDER THE MORE STABLE
INFLUENCE OF THE RIDGE DEPARTING TO OUR EAST.

WHILE THE MAIN COLD FRONT FROM THIS SYSTEM WILL NOT PUSH THROUGH THE
AREA UNTIL MONDAY NIGHT...WHAT IS LEFT OF THE WEAKENING FRONT NOW
EXTENDING FROM MINNESOTA DOWN INTO TEXAS WILL WORK EAST ACROSS LOWER
MICHIGAN TONIGHT. THIS SHOULD PROVIDE A BETTER FOCUS FOR
SHOWERS/TSTORMS. HIGHER RES RUNS CONTINUE TO SHOW THE CURRENT LINE
OF CONVECTION BREAKING...WITH MOST OF THE ACTIVITY LIFTING TO OUR
WEST AND NORTH...ONLY CLIPPING THE SAGINAW VALLEY. STILL...BETTER
INSTABILITY ARRIVING OVERNIGHT (ELEVATED) WARRANTS CHANCE-LIKELY
POPS AS IT WORKS THROUGH.

LONG TERM...MONDAY THROUGH SATURDAY

DEEP LAYER SOUTHWESTERLY FLOW FIRMLY IN PLACE ON MONDAY WITH THE
REGION STILL LARGELY OUTSIDE THE MAIN HEIGHT FALL CENTER AND
ASSOCIATED UPPER JET CORE ATTENDANT TO THE CLOSED LOW MEANDERING
ACROSS NORTHERN MN.  LEAD TROUGH AXIS TRANSLATING THROUGH TONIGHT
WILL SHUNT THE DEEPEST MOISTURE PLUME TO THE EAST BY MONDAY MORNING.
THE OVERALL REDUCTION IN MOISTURE QUALITY AND LACK OF AN APPARENT/
NECESSARY FORCING MECHANISM WITHIN THIS WELL MIXED WARM SECTOR
ENVIRONMENT WILL CONTAIN CONVECTIVE CHANCES PRIOR TO THE COLD
FRONTAL ARRIVAL.  ANY EARLY DAY LOW CLOUD DEBRIS WILL MIX OUT...
INCREASING THE LIKELIHOOD FOR SEEING A GOOD BIT OF SUN BY THE MIDDAY
PERIOD.   A SOLID LOOKING DIURNAL TEMPERATURE RESPONSE WITH HIGHS
MAKING A RUN INTO THE LOWER AND MIDDLE 80S.

COLD FRONTAL TIMING CENTERING ON THE 21Z-03Z PERIOD MONDAY
EVENING...AN ARRIVAL TIME CERTAINLY FAVORABLE TOWARD CAPITALIZING ON
THE BACK END OF PEAK HEATING.  EXISTING ENVIRONMENT LIKELY CARRYING
MLCAPE IN THE BALLPARK OF 1500 J/KG.  THIN RIBBON OF HIGHER THETA-E
ANCHORED ON THE BOUNDARY WILL HELP AUGMENT THIS DESTABILIZATION.
THE OVERALL FRONTAL POSITIONING AND TIMING WILL LEAVE A NARROW
WINDOW FOR CONVECTIVE INITIATION TO COMMENCE LOCALLY DURING THE
EVENING...ROUGHLY SOUTHEAST OF A HOWELL TO LAPEER LINE.  WHILE THE
STRONGER MID LEVEL WIND FIELD WILL RESIDE BEHIND THE FRONT...SOME
INCREASE IN DEEP LAYER SHEAR WILL OCCUR JUST AS THE FRONT ARRIVES.
MID LEVEL LAPSE RATES REMAIN MODEST...BUT GIVEN THE UNDERLYING LOW
LEVEL THERMODYNAMICS...POTENTIAL WILL EXIST FOR BETTER ORGANIZED
CELLS TO EMERGE WITH AN ACCOMPANYING ISOLATED SEVERE T-STORM RISK.

ENSUING POST-FRONTAL COLD AIR ADVECTION INCREASES HEADING INTO
TUESDAY...WITH 850 MB TEMPERATURES DROPPING A GOOD 15-20 DEGREES IN
24 HOURS.  THIS WILL LIKELY TRANSLATE INTO A BROAD STRATOCU FIELD
FOR TUESDAY...WITH TEMPERATURES STRUGGLING TO REACH MUCH ABOVE THE
60 DEGREE MARK.  DRY/STABLE PROFILE IN PLACE THROUGH THE MIDWEEK
PERIOD...CONDITIONS DEFINED BY LOW LEVEL ANTICYCLONIC FLOW TUCKED
BENEATH A WEAKLY CONFLUENT WEST-NORTHWEST MID LEVEL PATTERN.
SEASONABLY COOL AIR MASS LEFT TO RESPOND VIA A HIGHER DEGREE OF
INSOLATION ON WEDNESDAY...NO REAL ADVECTIVE COMPONENT IN PLACE.
SLOW MODERATION OF THIS ENVIRONMENT BY THURSDAY/FRIDAY AS UPPER
HEIGHTS START TO REBOUND.

MARINE...

FAVORABLE MARINE CONDITIONS IN TERMS OF WINDS AND WAVES TO FINISH
THE WEEKEND.  THE WARM AND INCREASINGLY HUMID CONDITIONS UNDER LIGHT
WIND WILL CONTINUE TO SUPPORT FOG OVER LAKE HURON THROUGH THE
MORNING HOURS.  A MARINE DENSE FOG ADVISORY REMAINS IN EFFECT SOUTH
OF SAGINAW BAY. THIS ENVIRONMENT WILL REMAIN FAVORABLE FOR THE
DEVELOPMENT OF SHOWERS AND THUNDERSTORMS THROUGH TONIGHT.  MODEST
SOUTHWESTERLY WINDS DEVELOP IN ADVANCE OF A COLD FRONT ON MONDAY.
COLD FRONT SWEEPS THROUGH MONDAY EVENING WITH COOLER AND DRIER
CONDITIONS DEVELOPING ON WEST TO NORTHWEST FLOW FOR THE MID WEEK
PERIOD.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...

MI...NONE.

LAKE HURON...DENSE FOG ADVISORY UNTIL 4 AM EDT MONDAY FOR LHZ421-422-441>443-
     462>464.

LAKE ST CLAIR...NONE.

MICHIGAN WATERS OF LAKE ERIE...NONE.

&&

$$

UPDATE.......BT
AVIATION.....HLO
SHORT TERM...HLO
LONG TERM....MR
MARINE.......MR


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).




AREA FORECAST DISCUSSION

NWS MARQUETTE MI

 759 AM EDT SUN MAY 17 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 528 AM EDT SUN MAY 17 2015

WATER VAPOR LOOP AND RAP ANALYSIS REVEALS WELL-DEFINED SHORTWAVE
LIFTING NORTH THROUGH THE CENTRAL PLAINS WITH PLUME OF DEEP GULF
MOISTURE STREAMING NORTH AHEAD OF IT. SFC ANALYSIS SHOWS DEWPOINTS
REACHING INTO THE LOWER 60S AS FAR NORTH AS HAYWARD AND SIREN WI.
LOWERING HEIGHT FALLS AHEAD OF THE APPROACHING SHORTWAVE COMBINED
WITH THE DEEPENING MOISTURE AND BUILDING INSTABILITY WILL PROVIDE
THE FOCUS FOR SHRA/TSRA OVER NW WI INTO UPPER MI LATER THIS
AFTERNOON INTO THIS EVENING.

TODAY AND TONIGHT...MODELS SHOW APPROACHING SHORTWAVE LIFTING NE
FROM THE CENTRAL PLAINS INTO THE UPPER LAKES BY THIS EVENING. THIS
WAVE SHOULD SPREAD SHRA/TSRA INTO THE AREA THIS AFTN AND EVENING AS
40-50 KT LOW-LEVEL JET AND PRECIPITABLE WATER AXIS OF GREATER THAN
1.5 INCHES TRANSLATES E. MODEL FCST DEEP LAYER SHEAR OF 40 TO 45 KTS
COULD SUPPORT WELL ORGANIZED STRONG STORMS AND ENHANCE SEVERE TSTM
RISK. HOWEVER...AMOUNT OF INSTABILITY REMAINS IN QUESTION AS
INCREASING CLOUD COVER AHEAD OF THE SHORTWAVE COULD SUPRESS
INSTABILITY. THE GFS...CANADIAN AND RAP MODELS INDICATE MLCAPE
VALUES OF 400-800 J/KG MLCAPE NOSING INTO MAINLY GOGEBIC AND IRON
COUNTIES BY THIS EVENING (00Z MON) AS NEW SPC DAY1 CONVECTIVE
OUTLOOK CONTINUES TO TARGET THESE COUNTIES AS WELL AS OTHER AREAS
ALONG THE WI BORDER FOR A SLIGHT RISK OF SVR STORMS THIS AFTERNOON
INTO THIS EVENING. THE MAIN THREATS FOR ISOLD SEVERE STORMS WOULD BE
LARGE HAIL AND DAMAGING WINDS. HIGH TEMPS WELL INTO THE 70S WILL BE
COMMON OVER THE W HALF OF THE FCST AREA TODAY WITH PERHAPS A FEW
LOCATIONS FAR WEST REACHING LOW 80S. SSE FLOW OFF LAKE MICHIGAN
SHOULD KEEP THE E COOLER...MAINLY LOW 70S INLAND AND MUCH COOLER
(AROUND 60F) ALONG SHORELINE.

EXPECT DIMINISHING SHRA/TSRA TO SPREAD E THRU THE EVENING AS
INSTABILITY WANES...AND THEN MOST OF THE AREA WILL PROBABLY BE DRY
OVERNIGHT. FOG COULD BECOME WIDESPREAD AND POSSIBLY DENSE LATER
TONIGHT OVER THE EAST HALF WITH ADDED MOISTURE FM DEPARTING SHRA AND
CONTINUED MOIST SSW FLOW OFF LAKE MICHIGAN. COULD ALSO BE SOME
UPSLOPE DZ INTO ERN ZONES LATE TONIGHT INTO MON MORNING.

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 407 AM EDT SUN MAY 17 2015

AS HAS BEEN TALKED ABOUT FOR SEVERAL DAYS...SPLIT FLOW WILL PERSIST
ACROSS THE CONTINENT FOR THE FORESEEABLE FUTURE...WITH STRONG
POSITIVE HEIGHT ANOMALIES ACROSS NW CANADA. THIS SHOULD KEEP THE
UPPER GREAT LAKES IN STRONGLY CONFLUENT FLOW FOR MUCH OF THE
FORECAST PERIOD BEYOND TUESDAY...YIELDING A DRY FORECAST INTO
MEMORIAL DAY WEEKEND.

AS FOR MONDAY...THE NWP ARE IN GOOD AGREEMENT IN SHOWING THE
OCCLUDED FRONT MOVING ACROSS THE AREA DURING THE MORNING HOURS. WITH
THE AREA BEING IN THE DRY SLOT IN THE MORNING AND STRONG
MID LEVEL Q-VECTOR DIVERGENCE...EXPECT ANY PRECIPITATION TO BE
CONFINED TO NEAR LAKE MICHIGAN WHERE MOIST ONSHORE FLOW WILL KEEP
CHANCES OF DRIZZLE/FOG IN THE MORNING HOURS BEFORE THE WINDS TURN
WESTERLY. BEHIND THE FRONT...COMMA HEAD MOISTURE WILL ATTEMPT TO
WRAP INTO THE AREA...BUT THE DEEPER MOISTURE WILL REMAIN OVER FAR
WESTERN LAKE SUPERIOR INTO MINNESOTA UNTIL LATE IN THE DAY INTO THE
OVERNIGHT HOURS. COULD BE A PASSING SHOWER MONDAY AFTERNOON ACROSS
THE WEST AND KEWEENAW AS THE DEEPER MOISTURE WRAPS IN BEHIND THE
FILLING AREA OF LOW PRESSURE AND INCREASING UPSLOPE FLOW DUE TO NW
WINDS. STRONG COLD ADVECTION AS THE UPPER TROUGH MOVES EAST OF THE
AREA WILL ALLOW FOR 850MB TEMPS TO DROP TO -9C ACROSS MUCH OF THE
AREA. THIS COMBINED WITH NW FLOW WILL ALLOW FOR ANY RAIN SHOWERS TO
CHANGE TO SNOW AND PERHAPS INCREASE IN AREAL COVERAGE ACROSS THE
WESTERN PART OF UPPER MICHIGAN. DUE TO THE COLD TEMPERATURES AND
PRECIPITATION OCCURING DURING THE OVERNIGHT HOURS...COULD NOT
TOTALLY RULE OUT A DUSTING TO LOCALLY AN INCH OVER GRASSY AREAS
MONDAY NIGHT INTO TUESDAY MORNING BUT GIVEN THE LACK OF SIGNIFICANT
SYNOPTIC SUPPORT DUE TO THE BEST UPPER ENERGY REMAINING WEST AND
NORTH OF THE AREA...DO NOT EXPECT ANY MORE THAN THAT AT THIS TIME.
COLD AND WINDY DAY ON TUESDAY WITH DRYING ACROSS THE ENTIRE AREA
LIKELY CAUSING ANY PRECIPITATION NEAR LAKE SUPERIOR TO SUBSIDE
DURING THE AFTERNOON HOURS.  STILL...IT WILL BE QUITE RAW WITH
TEMPERATURES 15-20 DEGREES BELOW NORMAL.

HEIGHTS BEGIN TO RISE ON WEDNESDAY AS THE UPPER RIDGE OVER THE
WRN ATLC BREAKS DOWN SLIGHTLY...ALLOWING THE LONG WAVE TROUGH OVER
THE REGION TO SHIFT EAST. THIS WILL ALLOW FOR SOME MODEST WARMING AT
850MB TO +4C BY WED EVENING ...WHICH COMBINED WITH THE SUNSHINE
SHOULD ALLOW FOR TEMPS TO GET AT LEAST INTO THE 50S OR LOWER 60S ON
WEDNESDAY....BUT STILL BELOW NORMAL FOR THIS TIME OF YEAR. CONTINUED
WARMING ON THURSDAY AHEAD OF AN UPPER DISTURBANCE ROTATING AROUND
THE UPPER LOW OVER NW QUEBEC. THE GFS AND ECMWF SUGGEST THIS UPPER
DISTURBANCE WILL CLIP THE UPPER GREAT LAKES THU NIGHT...HOWEVER
GIVEN THE VERY DRY AIRMASS IN PLACE ACROSS THE REGION NO
PRECIPITATION IS EXPECTED. WILL GO WITH SLIGHTLY COOLER TEMPS FRIDAY
AS 850MB TEMPS DROP BACK TO -1C. WARMER ON SATURDAY AND STILL DRY AS
HEIGHTS RISE ONCE AGAIN.
&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 747 AM EDT SUN MAY 17 2015

LOW IFR/LIFR STRATUS DEVELOPED THIS MORNING AT THE TAF SITES WITH
INCREASING MOISTURE AHEAD OF AN APPROACHING LOW PRES SYSTEM. SOME
PATCHY FOG ALSO FORMED...ESPECIALLY AT SAW WITH IFR CONDITIONS IN
UPSLOPE FLOW OFF LAKE MICHIGAN. LOW CEILINGS SHOULD MIX OUT AT CMX
AND MAYBE EVEN IWD DURING THE DAY TOMORROW BUT PERSISTENT UPSLOPE
FLOW WILL KEEP LOW CLOUDS AT SAW FOR MUCH OF THE DAY. SHOWER AND
ISOLATED THUNDER CHANCES WILL INCREASE FROM WEST TO EAST THROUGH THE
DAY. EXPECT GENERALLY IMPROVING CONDITIONS LATE THIS EVENING AND
OVERNIGHT AS SHRA EXIT EAST OF THE AREA. &&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 519 AM EDT SUN MAY 17 2015

LOW PRESSURE APPROACHING FROM THE SW WILL ALLOW FOR GRADUALLY
INCREASING E TO SE FLOW TODAY. GUSTS COULD REACH AS HIGH AS 30 KNOTS
FOR THE HIGHER PLATFORMS CENTRAL AND EAST. WARM AND MOIST AIR
SURGING NORTH AHEAD OF THE LOW WILL KEEP FOG IN THE FORECAST THROUGH
AT LEAST MONDAY MORNING BEFORE WINDS TURN NW AND DRIER AIR SCOURS
OUT THE FOG. FOG COULD GET DENSE LATER TONIGHT INTO MONDAY MORNING
OVER THE EAST HALF OF THE LAKE WITH ADDED MOISTENING FROM SHRA
MOVING ACROSS AREA. THE LOW WILL CROSS LAKE SUPERIOR MONDAY AND
MONDAY EVENING. THIS WILL USHER IN NW TO NNW WINDS OF 20 TO 30 KTS
MONDAY NIGHT AND TUESDAY...MAINLY NCNTRL AND EAST HALF. BROAD HIGH
PRESSURE WILL THEN BUILD ACROSS THE REGION WEDNESDAY THROUGH
FRIDAY...BRINGING WINDS DOWN BLO 20 KNOTS.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...VOSS
LONG TERM...MRD
AVIATION...VOSS
MARINE...VOSS




AREA FORECAST DISCUSSION

NWS DETROIT/PONTIAC MI

 732 AM EDT SUN MAY 17 2015

.AVIATION...

LOW CLOUDS AND FOG WILL QUICKLY LIFT BETWEEN 12-16Z THIS
MORNING...RESULTING IN HIGH-END MVFR CONDITIONS BY LATE MORNING. A
WARM AND MOIST AIRMASS WILL AGAIN BRING THE THREAT FOR SHOWERS AND
THUNDERSTORMS TODAY...HOWEVER COVERAGE AND TIMING ARE VERY UNCERTAIN
WITH A LACK OF STRONG FOCUSING MECHANISM AND ONLY WEAK INSTABILITY.
A BETTER CHANCE FOR SHOWERS AND THUNDERSTORMS WILL THEN EXIST
OVERNIGHT...ESPECIALLY FROM FNT NORTH...AS THE REMNANTS OF A COLD
FRONT MOVE ACROSS THE AREA.

FOR DTW...FOG AND LOW CEILINGS WILL LIFT THROUGH THE MORNING AS
SOUTH-SOUTHEAST WINDS BEGIN TO INCREASE. SHOWERS AND THUNDERSTORMS
WILL BE POSSIBLE TODAY...HOWEVER TIMING AND COVERAGE ARE TOO
UNCERTAIN AT THIS TIME TO HIGHLIGHT IN TAFS.

//DTW THRESHOLD PROBABILITIES...

* MEDIUM FOR CIG BELOW 5000 FEET THROUGH 00Z.

* LOW FOR A THUNDERSTORM TODAY AND TONIGHT.

* LOW FOR VISIBILITY BELOW 1/2SM AND CIGS BELOW 200 FEET AFTER 12Z
  THIS MORNING.

&&

.PREV DISCUSSION...ISSUED 359 AM EDT SUN MAY 17 2015

SHORT TERM...TODAY AND TONIGHT

LIGHT WINDS...BREAKS IN THE CLOUDS...AND RAINFALL YESTERDAY HAVE ALL
SET THE STAGE FOR FOG AND STRATUS TO FORM ONCE AGAIN THIS MORNING.
SO FAR VISIBILITIES HAVE PREDOMINANTLY RANGED FROM 1-5 MILES. THE
ARRIVAL OF ADDITIONAL CLOUDS SHOULD HELP PREVENT WIDESPREAD DENSE
FOG...BUT PATCHES ARE CERTAINLY POSSIBLE. WILL CONTINUE TO MONITOR
DENSE FOG POTENTIAL THROUGH THE MORNING HOURS HOWEVER.

UPPER RIDGE STILL REMAINS OVER THE SOUTHEAST CONUS...WITH LOWER
MICHIGAN POSITIONED ON THE WESTERN PERIPHERY. THE RIDGE AXIS WILL
SHIFT EAST TODAY AS THE LARGE UPPER TROUGH OVER THE CENTRAL U.S.
BEGINS TO LIFT TOWARDS THE UPPER MIDWEST. THE INFLUENCE OF THE RIDGE
WILL CONTINUE TO PROVIDE A STABILIZING INFLUENCE OVER THE AREA
THROUGH THE MORNING HOURS...WITH THERMAL PROFILES ON GFS/NAM
FORECAST SOUNDINGS STILL SHOWING WEAK LAPSE RATES IN THE MID-LEVELS
ASSOCIATED WITH THE WARMER AIR ALOFT. POTENTIAL FOR CONVECTION
THROUGH THE EARLY PART OF THE DAY LOOKS LIMITED THEREFORE...BUT
STILL POSSIBLE ALONG A FEW FEATURES. FRONTAL BOUNDARY REMAINS DRAPED
ACROSS CENTRAL LOWER MICHIGAN AS OF 300 AM THIS MORNING. THIS FRONT
WILL LIFT NORTHWARD THROUGH THE LATE MORNING AS SOUTHERLY FLOW
INCREASES AHEAD OF THE APPROACHING UPPER TROUGH. THE FRONT COULD
PROVIDE A FOCUS THIS MORNING FOR A FEW SHOWERS OR EVEN A TSTORM TO
FORM OVER THE SAGINAW VALLEY AND THUMB. FURTHER SOUTH IN THE WARM
SECTOR...UPPER SHORTWAVE MOVING EAST THROUGH THE OHIO VALLEY COULD
TRIGGER A FEW SHOWERS/TSTORMS NEAR THE BORDER.

AIRMASS WILL REMAIN VERY MOIST TODAY/TONIGHT WITH DEWPOINTS IN THE
60S. TEMPERATURES IN THE MID-LEVELS WILL MEANWHILE COOL SLIGHTLY
THROUGH THE DAY AS THE UPPER RIDGE AXIS PULLS EAST...WHILE THE
SURFACE LAYER HEATS TO AROUND 80F THIS AFTERNOON. AS THIS
OCCURS...WILL SEE INSTABILITY INCREASE THROUGH THE DAY AND BECOME
SURFACE BASED...WITH A PARCEL OF 80/65 YIELDING ABOUT 1000 J/KG OF
CAPE DURING THE LATE AFTERNOON. SEVERE WEATHER IS NOT EXPECTED
THROUGH LATE AFTERNOON AS SHEAR VALUES LOOK UNIMPRESSIVE AND CAPE
LOOKS TALL/SKINNY. VERY HEAVY DOWNPOURS WILL CONTINUE TO BE POSSIBLE
AS PW VALUES RISE FROM 1.5 INCHES THIS MORNING TO AROUND 1.75 INCHES
TONIGHT. WILL NEED TO FIND A TRIGGER FOR CONVECTION IN THE WARM
SECTOR TODAY/TONIGHT IN ORDER TO GET ANYTHING OTHER THAN JUST A FEW
CELLS POPPING UP HOWEVER. LOOKING BACK AT OBSERVATIONAL AND MODEL
DATA OVER THE CONUS FROM YESTERDAY...IT APPEARS AN OLD WARM FRONT
WAS CAST OFF THE SYSTEM OVER THE SOUTHERN/CENTRAL PLAINS EARLY
YESTERDAY. CURRENT OBSERVATIONS OVER SOUTEHRN ILLINOIS/INDIANA DO
INDICATE A SLIGHT "KINK" IN THE FLOW. THIS IS WHERE NAM/GFS MODELS
CURRENTLY PLACE THIS FEATURE...AND THEY BOTH LIFT IT THROUGH
SOUTHEAST MICHIGAN BETWEEN 14-22Z (PER THERMAL FIELDS AND HIGHER
THETA-E ADVECTION). COVERAGE OF SHOWERS/TSTORMS THAT COULD DEVELOP
AS THIS SUBTLE FEATURE WORKS THROUGH IS UNCERTAIN HOWEVER AS THE
ATMOSPHERE REMAINS JUICY BUT NOT OVERLY BUOYANT. KEPT COVERAGE AT
CHANCE AS HIGHER-RES RUNS OF THE 4KM WRF AND THE HRRR DO NOT SEEM
TOO KEEN ON WIDESPREAD CONVECTION DEVELOPING UNDER THE MORE STABLE
INFLUENCE OF THE RIDGE DEPARTING TO OUR EAST.

WHILE THE MAIN COLD FRONT FROM THIS SYSTEM WILL NOT PUSH THROUGH THE
AREA UNTIL MONDAY NIGHT...WHAT IS LEFT OF THE WEAKENING FRONT NOW
EXTENDING FROM MINNESOTA DOWN INTO TEXAS WILL WORK EAST ACROSS LOWER
MICHIGAN TONIGHT. THIS SHOULD PROVIDE A BETTER FOCUS FOR
SHOWERS/TSTORMS. HIGHER RES RUNS CONTINUE TO SHOW THE CURRENT LINE
OF CONVECTION BREAKING...WITH MOST OF THE ACTIVITY LIFTING TO OUR
WEST AND NORTH...ONLY CLIPPING THE SAGINAW VALLEY. STILL...BETTER
INSTABILITY ARRIVING OVERNIGHT (ELEVATED) WARRANTS CHANCE-LIKELY
POPS AS IT WORKS THROUGH.

LONG TERM...MONDAY THROUGH SATURDAY

DEEP LAYER SOUTHWESTERLY FLOW FIRMLY IN PLACE ON MONDAY WITH THE
REGION STILL LARGELY OUTSIDE THE MAIN HEIGHT FALL CENTER AND
ASSOCIATED UPPER JET CORE ATTENDANT TO THE CLOSED LOW MEANDERING
ACROSS NORTHERN MN.  LEAD TROUGH AXIS TRANSLATING THROUGH TONIGHT
WILL SHUNT THE DEEPEST MOISTURE PLUME TO THE EAST BY MONDAY MORNING.
THE OVERALL REDUCTION IN MOISTURE QUALITY AND LACK OF AN APPARENT/
NECESSARY FORCING MECHANISM WITHIN THIS WELL MIXED WARM SECTOR
ENVIRONMENT WILL CONTAIN CONVECTIVE CHANCES PRIOR TO THE COLD
FRONTAL ARRIVAL.  ANY EARLY DAY LOW CLOUD DEBRIS WILL MIX OUT...
INCREASING THE LIKELIHOOD FOR SEEING A GOOD BIT OF SUN BY THE MIDDAY
PERIOD.   A SOLID LOOKING DIURNAL TEMPERATURE RESPONSE WITH HIGHS
MAKING A RUN INTO THE LOWER AND MIDDLE 80S.

COLD FRONTAL TIMING CENTERING ON THE 21Z-03Z PERIOD MONDAY
EVENING...AN ARRIVAL TIME CERTAINLY FAVORABLE TOWARD CAPITALIZING ON
THE BACK END OF PEAK HEATING.  EXISTING ENVIRONMENT LIKELY CARRYING
MLCAPE IN THE BALLPARK OF 1500 J/KG.  THIN RIBBON OF HIGHER THETA-E
ANCHORED ON THE BOUNDARY WILL HELP AUGMENT THIS DESTABILIZATION.
THE OVERALL FRONTAL POSITIONING AND TIMING WILL LEAVE A NARROW
WINDOW FOR CONVECTIVE INITIATION TO COMMENCE LOCALLY DURING THE
EVENING...ROUGHLY SOUTHEAST OF A HOWELL TO LAPEER LINE.  WHILE THE
STRONGER MID LEVEL WIND FIELD WILL RESIDE BEHIND THE FRONT...SOME
INCREASE IN DEEP LAYER SHEAR WILL OCCUR JUST AS THE FRONT ARRIVES.
MID LEVEL LAPSE RATES REMAIN MODEST...BUT GIVEN THE UNDERLYING LOW
LEVEL THERMODYNAMICS...POTENTIAL WILL EXIST FOR BETTER ORGANIZED
CELLS TO EMERGE WITH AN ACCOMPANYING ISOLATED SEVERE T-STORM RISK.

ENSUING POST-FRONTAL COLD AIR ADVECTION INCREASES HEADING INTO
TUESDAY...WITH 850 MB TEMPERATURES DROPPING A GOOD 15-20 DEGREES IN
24 HOURS.  THIS WILL LIKELY TRANSLATE INTO A BROAD STRATOCU FIELD
FOR TUESDAY...WITH TEMPERATURES STRUGGLING TO REACH MUCH ABOVE THE
60 DEGREE MARK.  DRY/STABLE PROFILE IN PLACE THROUGH THE MIDWEEK
PERIOD...CONDITIONS DEFINED BY LOW LEVEL ANTICYCLONIC FLOW TUCKED
BENEATH A WEAKLY CONFLUENT WEST-NORTHWEST MID LEVEL PATTERN.
SEASONABLY COOL AIR MASS LEFT TO RESPOND VIA A HIGHER DEGREE OF
INSOLATION ON WEDNESDAY...NO REAL ADVECTIVE COMPONENT IN PLACE.
SLOW MODERATION OF THIS ENVIRONMENT BY THURSDAY/FRIDAY AS UPPER
HEIGHTS START TO REBOUND.

MARINE...

FAVORABLE MARINE CONDITIONS IN TERMS OF WINDS AND WAVES TO FINISH
THE WEEKEND.  THE WARM AND INCREASINGLY HUMID CONDITIONS UNDER LIGHT
WIND WILL CONTINUE TO SUPPORT FOG OVER LAKE HURON THROUGH THE
MORNING HOURS.  A MARINE DENSE FOG ADVISORY REMAINS IN EFFECT SOUTH
OF SAGINAW BAY. THIS ENVIRONMENT WILL REMAIN FAVORABLE FOR THE
DEVELOPMENT OF SHOWERS AND THUNDERSTORMS THROUGH TONIGHT.  MODEST
SOUTHWESTERLY WINDS DEVELOP IN ADVANCE OF A COLD FRONT ON MONDAY.
COLD FRONT SWEEPS THROUGH MONDAY EVENING WITH COOLER AND DRIER
CONDITIONS DEVELOPING ON WEST TO NORTHWEST FLOW FOR THE MID WEEK
PERIOD.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...DENSE FOG ADVISORY UNTIL NOON EDT TODAY FOR LHZ441>443-462>464.

LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&

$$

AVIATION.....HLO
SHORT TERM...HLO
LONG TERM....MR
MARINE.......MR

YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).




AREA FORECAST DISCUSSION

NWS MARQUETTE MI

 531 AM EDT SUN MAY 17 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 528 AM EDT SUN MAY 17 2015

WATER VAPOR LOOP AND RAP ANALYSIS REVEALS WELL-DEFINED SHORTWAVE
LIFTING NORTH THROUGH THE CENTRAL PLAINS WITH PLUME OF DEEP GULF
MOISTURE STREAMING NORTH AHEAD OF IT. SFC ANALYSIS SHOWS DEWPOINTS
REACHING INTO THE LOWER 60S AS FAR NORTH AS HAYWARD AND SIREN WI.
LOWERING HEIGHT FALLS AHEAD OF THE APPROACHING SHORTWAVE COMBINED
WITH THE DEEPENING MOISTURE AND BUILDING INSTABILITY WILL PROVIDE
THE FOCUS FOR SHRA/TSRA OVER NW WI INTO UPPER MI LATER THIS
AFTERNOON INTO THIS EVENING.

TODAY AND TONIGHT...MODELS SHOW APPROACHING SHORTWAVE LIFTING NE
FROM THE CENTRAL PLAINS INTO THE UPPER LAKES BY THIS EVENING. THIS
WAVE SHOULD SPREAD SHRA/TSRA INTO THE AREA THIS AFTN AND EVENING AS
40-50 KT LOW-LEVEL JET AND PRECIPITABLE WATER AXIS OF GREATER THAN
1.5 INCHES TRANSLATES E. MODEL FCST DEEP LAYER SHEAR OF 40 TO 45 KTS
COULD SUPPORT WELL ORGANIZED STRONG STORMS AND ENHANCE SEVERE TSTM
RISK. HOWEVER...AMOUNT OF INSTABILITY REMAINS IN QUESTION AS
INCREASING CLOUD COVER AHEAD OF THE SHORTWAVE COULD SUPRESS
INSTABILITY. THE GFS...CANADIAN AND RAP MODELS INDICATE MLCAPE
VALUES OF 400-800 J/KG MLCAPE NOSING INTO MAINLY GOGEBIC AND IRON
COUNTIES BY THIS EVENING (00Z MON) AS NEW SPC DAY1 CONVECTIVE
OUTLOOK CONTINUES TO TARGET THESE COUNTIES AS WELL AS OTHER AREAS
ALONG THE WI BORDER FOR A SLIGHT RISK OF SVR STORMS THIS AFTERNOON
INTO THIS EVENING. THE MAIN THREATS FOR ISOLD SEVERE STORMS WOULD BE
LARGE HAIL AND DAMAGING WINDS. HIGH TEMPS WELL INTO THE 70S WILL BE
COMMON OVER THE W HALF OF THE FCST AREA TODAY WITH PERHAPS A FEW
LOCATIONS FAR WEST REACHING LOW 80S. SSE FLOW OFF LAKE MICHIGAN
SHOULD KEEP THE E COOLER...MAINLY LOW 70S INLAND AND MUCH COOLER
(AROUND 60F) ALONG SHORELINE.

EXPECT DIMINISHING SHRA/TSRA TO SPREAD E THRU THE EVENING AS
INSTABILITY WANES...AND THEN MOST OF THE AREA WILL PROBABLY BE DRY
OVERNIGHT. FOG COULD BECOME WIDESPREAD AND POSSIBLY DENSE LATER
TONIGHT OVER THE EAST HALF WITH ADDED MOISTURE FM DEPARTING SHRA AND
CONTINUED MOIST SSW FLOW OFF LAKE MICHIGAN. COULD ALSO BE SOME
UPSLOPE DZ INTO ERN ZONES LATE TONIGHT INTO MON MORNING.

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 407 AM EDT SUN MAY 17 2015

AS HAS BEEN TALKED ABOUT FOR SEVERAL DAYS...SPLIT FLOW WILL PERSIST
ACROSS THE CONTINENT FOR THE FORESEEABLE FUTURE...WITH STRONG
POSITIVE HEIGHT ANOMALIES ACROSS NW CANADA. THIS SHOULD KEEP THE
UPPER GREAT LAKES IN STRONGLY CONFLUENT FLOW FOR MUCH OF THE
FORECAST PERIOD BEYOND TUESDAY...YIELDING A DRY FORECAST INTO
MEMORIAL DAY WEEKEND.

AS FOR MONDAY...THE NWP ARE IN GOOD AGREEMENT IN SHOWING THE
OCCLUDED FRONT MOVING ACROSS THE AREA DURING THE MORNING HOURS. WITH
THE AREA BEING IN THE DRY SLOT IN THE MORNING AND STRONG
MID LEVEL Q-VECTOR DIVERGENCE...EXPECT ANY PRECIPITATION TO BE
CONFINED TO NEAR LAKE MICHIGAN WHERE MOIST ONSHORE FLOW WILL KEEP
CHANCES OF DRIZZLE/FOG IN THE MORNING HOURS BEFORE THE WINDS TURN
WESTERLY. BEHIND THE FRONT...COMMA HEAD MOISTURE WILL ATTEMPT TO
WRAP INTO THE AREA...BUT THE DEEPER MOISTURE WILL REMAIN OVER FAR
WESTERN LAKE SUPERIOR INTO MINNESOTA UNTIL LATE IN THE DAY INTO THE
OVERNIGHT HOURS. COULD BE A PASSING SHOWER MONDAY AFTERNOON ACROSS
THE WEST AND KEWEENAW AS THE DEEPER MOISTURE WRAPS IN BEHIND THE
FILLING AREA OF LOW PRESSURE AND INCREASING UPSLOPE FLOW DUE TO NW
WINDS. STRONG COLD ADVECTION AS THE UPPER TROUGH MOVES EAST OF THE
AREA WILL ALLOW FOR 850MB TEMPS TO DROP TO -9C ACROSS MUCH OF THE
AREA. THIS COMBINED WITH NW FLOW WILL ALLOW FOR ANY RAIN SHOWERS TO
CHANGE TO SNOW AND PERHAPS INCREASE IN AREAL COVERAGE ACROSS THE
WESTERN PART OF UPPER MICHIGAN. DUE TO THE COLD TEMPERATURES AND
PRECIPITATION OCCURING DURING THE OVERNIGHT HOURS...COULD NOT
TOTALLY RULE OUT A DUSTING TO LOCALLY AN INCH OVER GRASSY AREAS
MONDAY NIGHT INTO TUESDAY MORNING BUT GIVEN THE LACK OF SIGNIFICANT
SYNOPTIC SUPPORT DUE TO THE BEST UPPER ENERGY REMAINING WEST AND
NORTH OF THE AREA...DO NOT EXPECT ANY MORE THAN THAT AT THIS TIME.
COLD AND WINDY DAY ON TUESDAY WITH DRYING ACROSS THE ENTIRE AREA
LIKELY CAUSING ANY PRECIPITATION NEAR LAKE SUPERIOR TO SUBSIDE
DURING THE AFTERNOON HOURS.  STILL...IT WILL BE QUITE RAW WITH
TEMPERATURES 15-20 DEGREES BELOW NORMAL.

HEIGHTS BEGIN TO RISE ON WEDNESDAY AS THE UPPER RIDGE OVER THE
WRN ATLC BREAKS DOWN SLIGHTLY...ALLOWING THE LONG WAVE TROUGH OVER
THE REGION TO SHIFT EAST. THIS WILL ALLOW FOR SOME MODEST WARMING AT
850MB TO +4C BY WED EVENING ...WHICH COMBINED WITH THE SUNSHINE
SHOULD ALLOW FOR TEMPS TO GET AT LEAST INTO THE 50S OR LOWER 60S ON
WEDNESDAY....BUT STILL BELOW NORMAL FOR THIS TIME OF YEAR. CONTINUED
WARMING ON THURSDAY AHEAD OF AN UPPER DISTURBANCE ROTATING AROUND
THE UPPER LOW OVER NW QUEBEC. THE GFS AND ECMWF SUGGEST THIS UPPER
DISTURBANCE WILL CLIP THE UPPER GREAT LAKES THU NIGHT...HOWEVER
GIVEN THE VERY DRY AIRMASS IN PLACE ACROSS THE REGION NO
PRECIPITATION IS EXPECTED. WILL GO WITH SLIGHTLY COOLER TEMPS FRIDAY
AS 850MB TEMPS DROP BACK TO -1C. WARMER ON SATURDAY AND STILL DRY AS
HEIGHTS RISE ONCE AGAIN.
&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 135 AM EDT SUN MAY 17 2015

ALL SITES ARE CURRENTLY VFR...BUT A TRICKY FORECAST FOR
THE OVERNIGHT AND SUNDAY TIME PERIODS. STRATUS AND SOME FOG WILL
DEVELOP OVERNIGHT TONIGHT...ESPECIALLY AT SAW WITH UPSLOPE FLOW OFF
LAKE MICHIGAN AT SAW AND POSSIBLY AT KCMX WITH UPSLOPE EASTERLY FLOW
OFF LAKE SUPERIOR. STRATUS SHOULD EVEN MAKE IT TO IWD LATE TONIGHT.
LOW CEILINGS SHOULD MIX OUT AT CMX AND MAYBE EVEN IWD DURING THE DAY
TOMORROW BUT PERSISTENT UPSLOPE FLOW WILL KEEP LOW CLOUDS AT SAW FOR
MUCH OF THE DAY. SHOWER AND ISOLATED THUNDER CHANCES WILL INCREASE
FROM WEST TO EAST THROUGH THE DAY.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 519 AM EDT SUN MAY 17 2015

LOW PRESSURE APPROACHING FROM THE SW WILL ALLOW FOR GRADUALLY
INCREASING E TO SE FLOW TODAY. GUSTS COULD REACH AS HIGH AS 30 KNOTS
FOR THE HIGHER PLATFORMS CENTRAL AND EAST. WARM AND MOIST AIR
SURGING NORTH AHEAD OF THE LOW WILL KEEP FOG IN THE FORECAST THROUGH
AT LEAST MONDAY MORNING BEFORE WINDS TURN NW AND DRIER AIR SCOURS
OUT THE FOG. FOG COULD GET DENSE LATER TONIGHT INTO MONDAY MORNING
OVER THE EAST HALF OF THE LAKE WITH ADDED MOISTENING FROM SHRA
MOVING ACROSS AREA. THE LOW WILL CROSS LAKE SUPERIOR MONDAY AND
MONDAY EVENING. THIS WILL USHER IN NW TO NNW WINDS OF 20 TO 30 KTS
MONDAY NIGHT AND TUESDAY...MAINLY NCNTRL AND EAST HALF. BROAD HIGH
PRESSURE WILL THEN BUILD ACROSS THE REGION WEDNESDAY THROUGH
FRIDAY...BRINGING WINDS DOWN BLO 20 KNOTS.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
  DENSE FOG ADVISORY UNTIL 6 AM EDT EARLY THIS MORNING FOR LMZ248-
     250.

&&

$$

SHORT TERM...VOSS
LONG TERM...MRD
AVIATION...MZ
MARINE...VOSS




AREA FORECAST DISCUSSION

NWS MARQUETTE MI

 521 AM EDT SUN MAY 17 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 519 AM EDT SUN MAY 17 2015

WATER VAPOR LOOP AND RAP ANALYSIS REVEALS WELL-DEFINED SHORTWAVE
LIFTING NORTH THROUGH THE CENTRAL PLAINS WITH PLUME OF DEEP GULF
MOISTURE STREAMING NORTH AHEAD OF IT. SFC ANALYSIS SHOWS DEWPOINTS
REACHING INTO THE LOWER 60S AS FAR NORTH AS HAYWARD AND SIREN WI.
LOWERING HEIGHT FALLS AHEAD OF THE APPROACHING SHORTWAVE COMBINED
WITH THE DEEPENING MOISTURE AND BUILDING INSTABILITY WILL PROVIDE
THE FOCUS FOR SOME SHRA/TSRA OVER NW WI INTO UPPER MI LATER THIS
AFTERNOON INTO THIS EVENING.

TODAY AND TONIGHT...MODELS SHOW APPROACHING SHORTWAVE LIFTING NE
FROM THE CENTRAL PLAINS INTO THE UPPER LAKES BY THIS EVENING. THIS
WAVE SHOULD SPREAD SHRA/TSRA INTO THE AREA THIS AFTN AND EVENING AS
40-50 KT LOW-LEVEL JET AND PRECIPITABLE WATER AXIS OF GREATER THAN
1.5 INCHES TRANSLATES E. MODEL FCST DEEP LAYER SHEAR OF 40 TO 45 KTS
COULD SUPPORT WELL ORGANIZED STRONG STORMS AND ENHANCE SEVERE TSTM
RISK. HOWEVER...AMOUNT OF INSTABILITY REMAINS IN QUESTION AS
INCREASING CLOUD COVER AHEAD OF THE SHORTWAVE COULD SUPRESS
INSTABILITY. THE GFS...CANADIAN AND RAP MODELS INDICATE MLCAPE
VALUES OF 400-800 J/KG MLCAPE NOSING INTO MAINLY GOGEBIC AND IRON
COUNTIES BY THIS EVENING (00Z MON) AS NEW SPC DAY1 CONVECTIVE
OUTLOOK CONTINUES TO TARGET THIS COUNTIES AS WELL AS OTHER AREAS
ALONG THE W BDR FOR A SLIGHT RISK OF SVR STORMS THIS AFTERNOON INTO
THIS EVENING. THE MAIN THREATS FROM ISOLD SEVERE STORMS WOULD BE
LARGE HAIL AND DAMAGING WINDS. HIGH TEMPS WELL INTO THE 70S WILL BE
COMMON OVER THE W HALF OF THE FCST AREA TODAY WITH PERHAPS A FEW
LOCATIONS FAR WEST REACHING LOW 80S. SSE FLOW OFF LAKE MICHIGAN
SHOULD KEEP THE E COOLER...MAINLY LOW 70S INLAND AND MUCH COOLER
(AROUND 60F) ALONG SHORELINE.

EXPECT DIMINISHING SHRA/TSRA TO SPREAD E THRU THE EVENING AS
INSTABILITY WANES...AND THEN MOST OF THE AREA WILL PROBABLY BE DRY
OVERNIGHT. FOG COULD BECOME WIDEPREAD AND POSSIBLY DENSE LATER
TONIGHT OVER THE EAST HALF WITH ADDED MOISTURE FM DEPARTING SHRA AND
CONTINUED MOIST SSW FLOW OFF LAKE MICHIGAN. COULD ALSO BE SOME
UPSLOPE DZ INTO ERN ZONES LATE TONIGHT INTO MON MORNING.

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 407 AM EDT SUN MAY 17 2015

AS HAS BEEN TALKED ABOUT FOR SEVERAL DAYS...SPLIT FLOW WILL PERSIST
ACROSS THE CONTINENT FOR THE FORESEEABLE FUTURE...WITH STRONG
POSITIVE HEIGHT ANOMALIES ACROSS NW CANADA. THIS SHOULD KEEP THE
UPPER GREAT LAKES IN STRONGLY CONFLUENT FLOW FOR MUCH OF THE
FORECAST PERIOD BEYOND TUESDAY...YIELDING A DRY FORECAST INTO
MEMORIAL DAY WEEKEND.

AS FOR MONDAY...THE NWP ARE IN GOOD AGREEMENT IN SHOWING THE
OCCLUDED FRONT MOVING ACROSS THE AREA DURING THE MORNING HOURS. WITH
THE AREA BEING IN THE DRY SLOT IN THE MORNING AND STRONG
MID LEVEL Q-VECTOR DIVERGENCE...EXPECT ANY PRECIPITATION TO BE
CONFINED TO NEAR LAKE MICHIGAN WHERE MOIST ONSHORE FLOW WILL KEEP
CHANCES OF DRIZZLE/FOG IN THE MORNING HOURS BEFORE THE WINDS TURN
WESTERLY. BEHIND THE FRONT...COMMA HEAD MOISTURE WILL ATTEMPT TO
WRAP INTO THE AREA...BUT THE DEEPER MOISTURE WILL REMAIN OVER FAR
WESTERN LAKE SUPERIOR INTO MINNESOTA UNTIL LATE IN THE DAY INTO THE
OVERNIGHT HOURS. COULD BE A PASSING SHOWER MONDAY AFTERNOON ACROSS
THE WEST AND KEWEENAW AS THE DEEPER MOISTURE WRAPS IN BEHIND THE
FILLING AREA OF LOW PRESSURE AND INCREASING UPSLOPE FLOW DUE TO NW
WINDS. STRONG COLD ADVECTION AS THE UPPER TROUGH MOVES EAST OF THE
AREA WILL ALLOW FOR 850MB TEMPS TO DROP TO -9C ACROSS MUCH OF THE
AREA. THIS COMBINED WITH NW FLOW WILL ALLOW FOR ANY RAIN SHOWERS TO
CHANGE TO SNOW AND PERHAPS INCREASE IN AREAL COVERAGE ACROSS THE
WESTERN PART OF UPPER MICHIGAN. DUE TO THE COLD TEMPERATURES AND
PRECIPITATION OCCURING DURING THE OVERNIGHT HOURS...COULD NOT
TOTALLY RULE OUT A DUSTING TO LOCALLY AN INCH OVER GRASSY AREAS
MONDAY NIGHT INTO TUESDAY MORNING BUT GIVEN THE LACK OF SIGNIFICANT
SYNOPTIC SUPPORT DUE TO THE BEST UPPER ENERGY REMAINING WEST AND
NORTH OF THE AREA...DO NOT EXPECT ANY MORE THAN THAT AT THIS TIME.
COLD AND WINDY DAY ON TUESDAY WITH DRYING ACROSS THE ENTIRE AREA
LIKELY CAUSING ANY PRECIPITATION NEAR LAKE SUPERIOR TO SUBSIDE
DURING THE AFTERNOON HOURS.  STILL...IT WILL BE QUITE RAW WITH
TEMPERATURES 15-20 DEGREES BELOW NORMAL.

HEIGHTS BEGIN TO RISE ON WEDNESDAY AS THE UPPER RIDGE OVER THE
WRN ATLC BREAKS DOWN SLIGHTLY...ALLOWING THE LONG WAVE TROUGH OVER
THE REGION TO SHIFT EAST. THIS WILL ALLOW FOR SOME MODEST WARMING AT
850MB TO +4C BY WED EVENING ...WHICH COMBINED WITH THE SUNSHINE
SHOULD ALLOW FOR TEMPS TO GET AT LEAST INTO THE 50S OR LOWER 60S ON
WEDNESDAY....BUT STILL BELOW NORMAL FOR THIS TIME OF YEAR. CONTINUED
WARMING ON THURSDAY AHEAD OF AN UPPER DISTURBANCE ROTATING AROUND
THE UPPER LOW OVER NW QUEBEC. THE GFS AND ECMWF SUGGEST THIS UPPER
DISTURBANCE WILL CLIP THE UPPER GREAT LAKES THU NIGHT...HOWEVER
GIVEN THE VERY DRY AIRMASS IN PLACE ACROSS THE REGION NO
PRECIPITATION IS EXPECTED. WILL GO WITH SLIGHTLY COOLER TEMPS FRIDAY
AS 850MB TEMPS DROP BACK TO -1C. WARMER ON SATURDAY AND STILL DRY AS
HEIGHTS RISE ONCE AGAIN.
&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 135 AM EDT SUN MAY 17 2015

ALL SITES ARE CURRENTLY VFR...BUT A TRICKY FORECAST FOR
THE OVERNIGHT AND SUNDAY TIME PERIODS. STRATUS AND SOME FOG WILL
DEVELOP OVERNIGHT TONIGHT...ESPECIALLY AT SAW WITH UPSLOPE FLOW OFF
LAKE MICHIGAN AT SAW AND POSSIBLY AT KCMX WITH UPSLOPE EASTERLY FLOW
OFF LAKE SUPERIOR. STRATUS SHOULD EVEN MAKE IT TO IWD LATE TONIGHT.
LOW CEILINGS SHOULD MIX OUT AT CMX AND MAYBE EVEN IWD DURING THE DAY
TOMORROW BUT PERSISTENT UPSLOPE FLOW WILL KEEP LOW CLOUDS AT SAW FOR
MUCH OF THE DAY. SHOWER AND ISOLATED THUNDER CHANCES WILL INCREASE
FROM WEST TO EAST THROUGH THE DAY.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 519 AM EDT SUN MAY 17 2015

LOW PRESSURE APPROACHING FROM THE SW WILL ALLOW FOR GRADUALLY
INCREASING E TO SE FLOW TODAY. GUSTS COULD REACH AS HIGH AS 30 KNOTS
FOR THE HIGHER PLATFORMS CENTRAL AND EAST. WARM AND MOIST AIR
SURGING NORTH AHEAD OF THE LOW WILL KEEP FOG IN THE FORECAST THROUGH
AT LEAST MONDAY MORNING BEFORE WINDS TURN NW AND DRIER AIR SCOURS
OUT THE FOG. FOG COULD GET DENSE LATER TONIGHT INTO MONDAY MORNING
OVER THE EAST HALF OF THE LAKE WITH ADDED MOISTENING FROM SHRA
MOVING ACROSS AREA. THE LOW WILL CROSS LAKE SUPERIOR MONDAY AND
MONDAY EVENING. THIS WILL USHER IN NW TO NNW WINDS OF 20 TO 30 KTS
MONDAY NIGHT AND TUESDAY...MAINLY NCNTRL AND EAST HALF. BROAD HIGH
PRESSURE WILL THEN BUILD ACROSS THE REGION WEDNESDAY THROUGH
FRIDAY...BRINGING WINDS DOWN BLO 20 KNOTS.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
  DENSE FOG ADVISORY UNTIL 6 AM EDT EARLY THIS MORNING FOR LMZ248-
     250.

&&

$$

SHORT TERM...VOSS
LONG TERM...MRD
AVIATION...MZ
MARINE...VOSS




AREA FORECAST DISCUSSION

NWS DETROIT/PONTIAC MI

 359 AM EDT SUN MAY 17 2015

.SHORT TERM...TODAY AND TONIGHT

LIGHT WINDS...BREAKS IN THE CLOUDS...AND RAINFALL YESTERDAY HAVE ALL
SET THE STAGE FOR FOG AND STRATUS TO FORM ONCE AGAIN THIS MORNING.
SO FAR VISIBILITIES HAVE PREDOMINANTLY RANGED FROM 1-5 MILES. THE
ARRIVAL OF ADDITIONAL CLOUDS SHOULD HELP PREVENT WIDESPREAD DENSE
FOG...BUT PATCHES ARE CERTAINLY POSSIBLE. WILL CONTINUE TO MONITOR
DENSE FOG POTENTIAL THROUGH THE MORNING HOURS HOWEVER.

UPPER RIDGE STILL REMAINS OVER THE SOUTHEAST CONUS...WITH LOWER
MICHIGAN POSITIONED ON THE WESTERN PERIPHERY. THE RIDGE AXIS WILL
SHIFT EAST TODAY AS THE LARGE UPPER TROUGH OVER THE CENTRAL U.S.
BEGINS TO LIFT TOWARDS THE UPPER MIDWEST. THE INFLUENCE OF THE RIDGE
WILL CONTINUE TO PROVIDE A STABILIZING INFLUENCE OVER THE AREA
THROUGH THE MORNING HOURS...WITH THERMAL PROFILES ON GFS/NAM
FORECAST SOUNDINGS STILL SHOWING WEAK LAPSE RATES IN THE MID-LEVELS
ASSOCIATED WITH THE WARMER AIR ALOFT. POTENTIAL FOR CONVECTION
THROUGH THE EARLY PART OF THE DAY LOOKS LIMITED THEREFORE...BUT
STILL POSSIBLE ALONG A FEW FEATURES. FRONTAL BOUNDARY REMAINS DRAPED
ACROSS CENTRAL LOWER MICHIGAN AS OF 300 AM THIS MORNING. THIS FRONT
WILL LIFT NORTHWARD THROUGH THE LATE MORNING AS SOUTHERLY FLOW
INCREASES AHEAD OF THE APPROACHING UPPER TROUGH. THE FRONT COULD
PROVIDE A FOCUS THIS MORNING FOR A FEW SHOWERS OR EVEN A TSTORM TO
FORM OVER THE SAGINAW VALLEY AND THUMB. FURTHER SOUTH IN THE WARM
SECTOR...UPPER SHORTWAVE MOVING EAST THROUGH THE OHIO VALLEY COULD
TRIGGER A FEW SHOWERS/TSTORMS NEAR THE BORDER.

AIRMASS WILL REMAIN VERY MOIST TODAY/TONIGHT WITH DEWPOINTS IN THE
60S. TEMPERATURES IN THE MID-LEVELS WILL MEANWHILE COOL SLIGHTLY
THROUGH THE DAY AS THE UPPER RIDGE AXIS PULLS EAST...WHILE THE
SURFACE LAYER HEATS TO AROUND 80F THIS AFTERNOON. AS THIS
OCCURS...WILL SEE INSTABILITY INCREASE THROUGH THE DAY AND BECOME
SURFACE BASED...WITH A PARCEL OF 80/65 YIELDING ABOUT 1000 J/KG OF
CAPE DURING THE LATE AFTERNOON. SEVERE WEATHER IS NOT EXPECTED
THROUGH LATE AFTERNOON AS SHEAR VALUES LOOK UNIMPRESSIVE AND CAPE
LOOKS TALL/SKINNY. VERY HEAVY DOWNPOURS WILL CONTINUE TO BE POSSIBLE
AS PW VALUES RISE FROM 1.5 INCHES THIS MORNING TO AROUND 1.75 INCHES
TONIGHT. WILL NEED TO FIND A TRIGGER FOR CONVECTION IN THE WARM
SECTOR TODAY/TONIGHT IN ORDER TO GET ANYTHING OTHER THAN JUST A FEW
CELLS POPPING UP HOWEVER. LOOKING BACK AT OBSERVATIONAL AND MODEL
DATA OVER THE CONUS FROM YESTERDAY...IT APPEARS AN OLD WARM FRONT
WAS CAST OFF THE SYSTEM OVER THE SOUTHERN/CENTRAL PLAINS EARLY
YESTERDAY. CURRENT OBSERVATIONS OVER SOUTEHRN ILLINOIS/INDIANA DO
INDICATE A SLIGHT "KINK" IN THE FLOW. THIS IS WHERE NAM/GFS MODELS
CURRENTLY PLACE THIS FEATURE...AND THEY BOTH LIFT IT THROUGH
SOUTHEAST MICHIGAN BETWEEN 14-22Z (PER THERMAL FIELDS AND HIGHER
THETA-E ADVECTION). COVERAGE OF SHOWERS/TSTORMS THAT COULD DEVELOP
AS THIS SUBTLE FEATURE WORKS THROUGH IS UNCERTAIN HOWEVER AS THE
ATMOSPHERE REMAINS JUICY BUT NOT OVERLY BUOYANT. KEPT COVERAGE AT
CHANCE AS HIGHER-RES RUNS OF THE 4KM WRF AND THE HRRR DO NOT SEEM
TOO KEEN ON WIDESPREAD CONVECTION DEVELOPING UNDER THE MORE STABLE
INFLUENCE OF THE RIDGE DEPARTING TO OUR EAST.

WHILE THE MAIN COLD FRONT FROM THIS SYSTEM WILL NOT PUSH THROUGH THE
AREA UNTIL MONDAY NIGHT...WHAT IS LEFT OF THE WEAKENING FRONT NOW
EXTENDING FROM MINNESOTA DOWN INTO TEXAS WILL WORK EAST ACROSS LOWER
MICHIGAN TONIGHT. THIS SHOULD PROVIDE A BETTER FOCUS FOR
SHOWERS/TSTORMS. HIGHER RES RUNS CONTINUE TO SHOW THE CURRENT LINE
OF CONVECTION BREAKING...WITH MOST OF THE ACTIVITY LIFTING TO OUR
WEST AND NORTH...ONLY CLIPPING THE SAGINAW VALLEY. STILL...BETTER
INSTABILITY ARRIVING OVERNIGHT (ELEVATED) WARRANTS CHANCE-LIKELY
POPS AS IT WORKS THROUGH.

&&

.LONG TERM...MONDAY THROUGH SATURDAY

DEEP LAYER SOUTHWESTERLY FLOW FIRMLY IN PLACE ON MONDAY WITH THE
REGION STILL LARGELY OUTSIDE THE MAIN HEIGHT FALL CENTER AND
ASSOCIATED UPPER JET CORE ATTENDANT TO THE CLOSED LOW MEANDERING
ACROSS NORTHERN MN.  LEAD TROUGH AXIS TRANSLATING THROUGH TONIGHT
WILL SHUNT THE DEEPEST MOISTURE PLUME TO THE EAST BY MONDAY MORNING.
THE OVERALL REDUCTION IN MOISTURE QUALITY AND LACK OF AN APPARENT/
NECESSARY FORCING MECHANISM WITHIN THIS WELL MIXED WARM SECTOR
ENVIRONMENT WILL CONTAIN CONVECTIVE CHANCES PRIOR TO THE COLD
FRONTAL ARRIVAL.  ANY EARLY DAY LOW CLOUD DEBRIS WILL MIX OUT...
INCREASING THE LIKELIHOOD FOR SEEING A GOOD BIT OF SUN BY THE MIDDAY
PERIOD.   A SOLID LOOKING DIURNAL TEMPERATURE RESPONSE WITH HIGHS
MAKING A RUN INTO THE LOWER AND MIDDLE 80S.

COLD FRONTAL TIMING CENTERING ON THE 21Z-03Z PERIOD MONDAY
EVENING...AN ARRIVAL TIME CERTAINLY FAVORABLE TOWARD CAPITALIZING ON
THE BACK END OF PEAK HEATING.  EXISTING ENVIRONMENT LIKELY CARRYING
MLCAPE IN THE BALLPARK OF 1500 J/KG.  THIN RIBBON OF HIGHER THETA-E
ANCHORED ON THE BOUNDARY WILL HELP AUGMENT THIS DESTABILIZATION.
THE OVERALL FRONTAL POSITIONING AND TIMING WILL LEAVE A NARROW
WINDOW FOR CONVECTIVE INITIATION TO COMMENCE LOCALLY DURING THE
EVENING...ROUGHLY SOUTHEAST OF A HOWELL TO LAPEER LINE.  WHILE THE
STRONGER MID LEVEL WIND FIELD WILL RESIDE BEHIND THE FRONT...SOME
INCREASE IN DEEP LAYER SHEAR WILL OCCUR JUST AS THE FRONT ARRIVES.
MID LEVEL LAPSE RATES REMAIN MODEST...BUT GIVEN THE UNDERLYING LOW
LEVEL THERMODYNAMICS...POTENTIAL WILL EXIST FOR BETTER ORGANIZED
CELLS TO EMERGE WITH AN ACCOMPANYING ISOLATED SEVERE T-STORM RISK.

ENSUING POST-FRONTAL COLD AIR ADVECTION INCREASES HEADING INTO
TUESDAY...WITH 850 MB TEMPERATURES DROPPING A GOOD 15-20 DEGREES IN
24 HOURS.  THIS WILL LIKELY TRANSLATE INTO A BROAD STRATOCU FIELD
FOR TUESDAY...WITH TEMPERATURES STRUGGLING TO REACH MUCH ABOVE THE
60 DEGREE MARK.  DRY/STABLE PROFILE IN PLACE THROUGH THE MIDWEEK
PERIOD...CONDITIONS DEFINED BY LOW LEVEL ANTICYCLONIC FLOW TUCKED
BENEATH A WEAKLY CONFLUENT WEST-NORTHWEST MID LEVEL PATTERN.
SEASONABLY COOL AIR MASS LEFT TO RESPOND VIA A HIGHER DEGREE OF
INSOLATION ON WEDNESDAY...NO REAL ADVECTIVE COMPONENT IN PLACE.
SLOW MODERATION OF THIS ENVIRONMENT BY THURSDAY/FRIDAY AS UPPER
HEIGHTS START TO REBOUND.

&&

.MARINE...

FAVORABLE MARINE CONDITIONS IN TERMS OF WINDS AND WAVES TO FINISH
THE WEEKEND.  THE WARM AND INCREASINGLY HUMID CONDITIONS UNDER LIGHT
WIND WILL CONTINUE TO SUPPORT FOG OVER LAKE HURON THROUGH THE
MORNING HOURS.  A MARINE DENSE FOG ADVISORY REMAINS IN EFFECT SOUTH
OF SAGINAW BAY. THIS ENVIRONMENT WILL REMAIN FAVORABLE FOR THE
DEVELOPMENT OF SHOWERS AND THUNDERSTORMS THROUGH TONIGHT.  MODEST
SOUTHWESTERLY WINDS DEVELOP IN ADVANCE OF A COLD FRONT ON MONDAY.
COLD FRONT SWEEPS THROUGH MONDAY EVENING WITH COOLER AND DRIER
CONDITIONS DEVELOPING ON WEST TO NORTHWEST FLOW FOR THE MID WEEK
PERIOD.

&&

.AVIATION...ISSUED 1200 AM EDT SUN MAY 17 2015

WITH SHOWERS ACTIVITY ALONG THE FRONT DYING DOWN...ATTENTION BEGINS
TO SHIFT TOWARD THE FOG POTENTIAL. USING LAST NIGHT AS A GUIDE AS
WELL AS CURRENT TRENDS IN OBS...LOOKS GOOD FOR ALL LOCATIONS TO DROP
TO AT LEAST MVFR FOR VSBY/CIGS WITH IFR LIKELY FOR A FEW HOURS AS
WELL. TIMING THE IFR WILL LIKELY BE THE CHALLENGE AS EARLY ON THERE
IS WIDELY VARYING CONDITIONS ACROSS SE MI. THE FRONT WILL REMAIN
DRAPED ACROSS THE MBS/FNT LOCATIONS WHICH WILL AGAIN LEAD TO CHANCES
OF SHOWERS AND THUNDERSTORMS DURING THE AFTERNOON TODAY...BUT
COVERAGE AND TIMING ILL DEFINED AT THE MOMENT SO WILL HOLD OFF ON
INCLUDING IN THE TAF. BETTER CHANCES FOR PRECIP COMES AROUND 00Z FOR
MBS/FNT AS A PREFRONTAL BOUNDARY WORKS ACROSS THE AREA.

FOR DTW...MVFR FOG ALREADY DEVELOPING OVER THE TERMINAL WITH
POTENTIAL FOR IFR CONDITIONS BY MORNING. AS THE FOG DISSIPATES
THROUGH THE MORNING HOURS...ATTENTION THEN TURNS BACK TO CONVECTIVE
POTENTIAL FOR THE AFTERNOON AND OVERNIGHT HOURS. NOT ENOUGH
CONFIDENCE IN COVERAGE ATTM TO INCLUDE IN THE TAF.

//DTW THRESHOLD PROBABILITIES...

* MEDIUM FOR CIGS AOB 5KFT AFTER 09Z.

* LOW FOR VISIBILITY BELOW 1/2 MILE EARLY THIS MORNING.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...DENSE FOG ADVISORY UNTIL NOON EDT TODAY FOR LHZ441>443-462>464.

LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&

$$

SHORT TERM...HLO
LONG TERM....MR
MARINE.......MR
AVIATION.....DRK


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).



AREA FORECAST DISCUSSION

NWS TWIN CITIES/CHANHASSEN MN

 412 PM CDT SUN MAY 17 2015

.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 412 PM CDT SUN MAY 17 2015

THUNDERSTORMS HAVE BECOME FAIRLY WIDESPREAD THIS AFTERNOON TO THE
EAST OF A COLD FRONT THAT IS ADVANCING EAST ACROSS MN. THE SFC LOW
DRIVING THIS FRONT WAS DOWN TO 995 MB AND SPINNING RATHER
AGGRESSIVELY ACROSS NE SODAK. BASED ON SFC PRESSURE FALLS...THIS LOW
WILL BE ON ITS WAY OFF TO THE ARROWHEAD TONIGHT. WE HAVE QUITE THE
CONTRAST IN AIRMASSES ACROSS THE SYSTEM...WITH SUMMER-LIKE AIR TO
ITS EAST WITH TEMPERATURES IN THE 70S AND DEWPS IN THE 60S...WHILE
WEST OF THE LOW...TEMPERATURES ARE DOWN IN THE MID 30S ACROSS NODAK.
IN FACT...IT IS COLD ENOUGH ON THE WRN EDGE OF THE PRECIP SHIELD
THAT WE ARE SEEING A RAIN/SNOW MIX THIS AFTERNOON.

FOR THE REST OF TODAY...LIKE THE IDEA THAT THE HRRR HAS BEEN RUNNING
WITH ALL DAY THAT MATCHES WELL WITH REALITY NOW. AND THAT IS FOR THE
WIDESPREAD DISCRETE CELLS TO CONTINUE THROUGH THE EVENING AHEAD OF
THE COLD FRONT. WE HAVE SEEN SBCAPE INCREASE TO BETWEEN 1000 AND
1500 J/KG...BUT WITH LITTLE CIN IN PLACE...WE ARE BASICALLY POPPING
CONVECTION AS SOON AS INSTABILITY DEVELOPS. MID-LEVEL LAPSE RATES
ARE PRETTY WEAK THOUGH...WHICH IS A BIG LIMITING FACTOR IN THE SVR.
STILL...FREEZING LEVELS HAVE DROPPED FROM ALMOST 12K FT AGL
YESTERDAY TO BETWEEN 8K AND 9K FEET TODAY...WHICH WILL CONTINUE TO
ALLOW FOR THE THREAT FOR MARGINALLY SVR HAIL THROUGH THE EVENING.
GIVEN THE DEPTH OF THE SYSTEM IN TO OUR NW...WE ARE SEEING LOTS OF
WIND THROUGH PRETTY MUCH THE WHOLE DEPTH OF THE ATMO...SO THESE
SHOWERS WILL LIKELY BE ABLE TO MIX SOME OF THAT DOWN...LEADING TO
SOME GUSTY WINDS AS WELL. TORNADO THREAT DOES NOT LOOK AS GOOD AS
YESTERDAY...WHEN WE HAD A WARM FRONT DRAPED ACROSS THE STATE...BUT
THE RAP HAS BEEN SHOWING 0-1 SHEAR INCREASING LATE THIS AFTERNOON
ACROSS ERN MN/WRN WI...WHERE THE BEST CHANCE FOR SEEING A BRIEF
TORNADO WOULD EXIST.

FOR TONIGHT...THE BIG THING WE WILL SEE IS STRONG CAA AS THE LOW
PUSHES TOWARD THE ARROWHEAD. THIS WILL LEAD TO SOME AGGRESSIVE
TEMPERATURE DROPS OVERNIGHT...WHERE LOWS IN WRN MN WILL FALL BACK
INTO THE MID 30S...OR ABOUT 35 DEGREES COLDER THAN THE HIGHS WERE
THIS AFTERNOON. IN ADDITION TO THE COLD AIR...WE WILL SEE WRAP
AROUND PRECIP DIP DOWN ABOUT AS FAR SOUTH AS A MADISON TO MILLE LACS
LAKE LINE. FORECAST SOUNDINGS IN THIS AREA ARE ALSO COLD ENOUGH TO
SHOW A RAIN/SLEET MIX DEVELOPING LATE TONIGHT. IN FACT...THE NAM
WOULD SAY THE P-TYPE AT AXN WILL BE ALL SLEET TOMORROW MORNING...SO
DID INTRODUCE A PRECIP MIX INTO THE GRIDS. BESIDE THE PRECIP...WINDS
WILL BE STRONG AS WELL. TOP OF THE CHANNEL MIX DOWN AT MOST SITES IN
MN IS OVER 40 KTS. WE ARE RIGHT ON THE CUSP OF NEEDING A WIND
ADVY...BUT DECIDED TO HOLD OFF ON ONE FOR NOW AND WILL LET THE
SEVERE POTENTIAL PLAY OUT BEFORE HOISTING A WIND ADVY.

FOR MONDAY...THERE IS NO WAY AROUND IT...IT WILL BE A RAW DAY. NAM
HAS H85 TEMPS DROPPING TO BETWEEN -5 AND -8C...WHICH IS BELOW THE
CLIMATOLOGICAL RECORD FOR H85 TEMPS FOR THE DAY AT STC/MPX. THROW IN
THE MOSTLY CLOUDY SKIES...AND HAVE HIGH CONFIDENCE IN HIGHS STAYING
IN THE 40S...WITH HIGHS ONLY IN THE 30S OUT TOWARD AXN. THESE VALUES
WILL BE IN THE 25 TO 35 DEGREES BELOW NORMAL RANGE.

.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 412 PM CDT SUN MAY 17 2015

THE AFOREMENTIONED STRONG COLD ADVECTION ON MONDAY WILL KEEP THE
LOCAL AREA COOL ON TUESDAY AS WELL WITH HIGHS LIKELY REMAINING IN
THE 50S. THE TROUGH MOVES EAST BY WEDNESDAY AND EAST COAST TROUGH
SHEARS OUT BEFORE ADVANCING OUT OF THE ROCKIES. THEREFORE WE
SHOULD SEE DRY WEATHER AND COOL TO MILD TEMPERATURES THROUGH THE
WEEK...WITH A SLOW WARMING TREND TIME. WE EXPECT TUESDAY AND
WEDNESDAY MORNINGS TO FALL INTO THE 30S ACROSS CENTRAL MN AND WEST
CENTRAL WI...SO WE COULD SEE A LITTLE FROST IF WE MANAGE TO
GET CLEARING AND THE WINDS STAY CALM. WEDNESDAY MORNING HAS A
BETTER CHANCE OF A CALM WIND AND AT LEAST PARTIAL CLEARING. THE
NEXT CHANCE FOR THUNDERSTORMS WILL LIKELY HOLD OFF UNTIL THE
WEEKEND WHEN ANOTHER TROUGH APPROACHES THE REGION FROM THE PLAINS.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 125 PM CDT SUN MAY 17 2015

LIKE THE IDEA OF THE HRRR...WITH WIDESPREAD SHOWERS AND
THUNDERSTORMS DEVELOPING THIS AFTERNOON AS THE STACKED LOW MOVES
THROUGH MN WITH MARGINAL INSTABILITY BUT VIRTUALLY NO CIN. DECIDED
TO CONTINUE TREND OF HANDLING THIS SCENARIO WITH VC GROUPS AND
EXTENDED TEMPO GROUPS FOR THUNDER. HAVE HIGH CONFIDENCE IN STORMS
OCCURRING...JUST LOW CONFIDENCE ON TIMING/TRACKS OF THE NUMEROUS
STORMS THAT ARE EXPECTED. AS WE GET BEHIND THE COLD FRONT...LOW
STRATUS BACK OVER THE DAKOTAS WILL SWING THROUGH...WITH TIMING ON
ITS ARRIVAL NOT TOO DIFFERENT BETWEEN THE HRRR/SREF/NAM/LAMP...SO
MAIN ISSUE WITH THAT IS MORE HOW LOW WILL IT BE AS OPPOSED TO WHEN
WILL THOSE CLOUDS GET TO EACH AIRPORT. MAIN CHANGE MADE TO THE
PREVIOUS TAF WAS TO GO WITH MORE WINDS GIVEN STRENGTH OF MIXED
LAYER WINDS ON NAM SOUNDINGS...WOULD NOT BE SURPRISED TO SEE SOME
WIND GUSTS IN WRN MN TONIGHT THROUGH MON MORNING GET INTO THE 40S
KTS.

KMSP...ALREADY SEEING SHOWERS BUBBLE UP AT 18Z...AND THINKING
THIS THEME OF SCT SHOWERS/STORMS WILL BE WITH US THROUGH ABOUT 1Z.
TEMPO GROUP FOR THUNDER IS BASED ON WHEN THE HRRR BRINGS THE
GREATEST COVERAGE OF STORMS THROUGH. ALSO HAVE HIGH CONFIDENCE IN
MVFR CIGS RETURNING TONIGHT. THOUGH HAVE KEPT CIGS ABOVE 017...MAY
CIGS GET DOWN BETWEEN 010-015 DURING THE MORNING ON MONDAY. WINDS
COULD ALSO BE PROBLEMATIC MONDAY MORNING...WITH STRONG CROSS
WINDS EXPECTED IN THE EARLY MORNING BEFORE WINDS CONTINUE TO VEER
MORE TOWARD A 300 DIRECTION IN THE AFTERNOON.

/OUTLOOK FOR KMSP/
TUE...MVFR CIGS EARLY. WINDS N AT 10 KTS.
WED...VFR. WINDS NNE 5 KTS.
THU...VFR. WINDS NNW 5 KTS.


&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&

$$

SHORT TERM...MPG
LONG TERM...CLF
AVIATION...MPG




AREA FORECAST DISCUSSION

NWS TWIN CITIES/CHANHASSEN MN

 125 PM CDT SUN MAY 17 2015

.UPDATE...

SKIES ARE CLEARING OUT ACROSS THE AREA LATE THIS MORNING AS A
PRONOUNCED MID-LEVEL DRY SLOT TODAY. BIGGEST CHANGE SEEN WITH THE
SEVERE THREAT TODAY IS IT IS NOT LOOKING AS GREAT. THE BIGGEST
REASON IS INSTABILITY LOOKS MARGINAL TODAY...WITH MLCAPES
LARGELY STAYING UNDER 1000 J/KG. THE BIGGEST ISSUE IS WE HAVE
BROAD FORCING WITH THE UPPER WAVE MOVING ACROSS THE REGION WITH AN
UNCAPPED ENVIRONMENT. THE LIMITED CAPPING MEANS AS SOON AS A
LITTLE BIT OF INSTABILITY IS ACHIEVED...CONVECTION WILL BE
INITIATED...WHICH WILL QUICKLY START TO CONSUME ANY CAPE PRESENT.
GIVEN THE LOW LEVEL WIND FIELDS...STRONG WINDS WILL LIKELY BE THE
MAIN THREAT...WITH THE TORNADO THREAT INCREASING SOME THIS
AFTERNOON AS O-1KM INCREASES AHEAD OF THE EWRD ADVANCING COLD
FRONT.

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 405 AM CDT SUN MAY 17 2015

AN ACTIVE WEATHER DAY IS AHEAD...AS A NEARLY STACKED LOW PRESSURE
SYSTEM PIVOTS ACROSS WESTERN/NORTHERN MINNES0TA.

THE COMPLEX OF SHOWERS AND THUNDERSTORMS THAT BLOSSOMED OVER MO/IA
WILL LIFT NORTH ACROSS SOUTHERN/CENTRAL MN THIS MORNING. BY
18Z...THE BULK OF THE FORECAST AREA SHOULD BE EXPERIENCING A LULL
IN THE ACTIVITY AS SAID CONVECTION LIFTS INTO NORTHERN MN. THE
ASSOCIATED CONVECTIVE DEBRIS /CLOUD COVER/ MAY INITIALLY HINDER
THUNDERSTORM REDEVELOPMENT...BUT AN IMPRESSIVE PUNCH OF PV
ADVECTION WILL LIFT INTO CENTRAL/EASTERN MN BY MID AFTERNOON. MID
LEVEL DRYING IS FORECAST TO WORK INTO SOUTHEAST/EAST CENTRAL MN
THIS AFTERNOON AS WELL...WHICH SHOULD YIELD ADEQUATE SCATTERING
OF THE LOW CLOUDS TO TRIGGER SUFFICIENT ATMOSPHERIC
DESTABILIZATION IN THE WARM SECTOR OVER OUR AREA. SUPERCELL
THUNDERSTORM MODE LOOKS LIKELY...GIVEN THE EXTENT OF DEEP LAYER
SHEAR...AND SFC-3KM PARAMETER VALUES ILLUSTRATE A THREAT FOR
TORNADOES...EVEN THOUGH THE WARM FRONT IS NORTH OF THE AREA. THE
PRIMARY WINDOW FOR SEVERE STORMS LOOKS TO OCCUR BETWEEN 18Z AND
23Z...WITH THE HIGHEST THREAT AREA BEING LOCATIONS ALONG/EAST OF
THE INTERSTATE 35 CORRIDOR. HEAVY RAINFALL WILL BE POSSIBLE AGAIN
TODAY IN THE STRONGER STORMS...ALTHOUGH IT WILL OCCUR PRIMARILY
EAST OF WHERE THE HIGHER TOTALS OCCURRED ON SATURDAY...SO DO NOT
HAVE STRONG FLOODING CONCERNS ABOVE AND BEYOND GENERAL PONDING
ISSUES.

HIGH TEMPS TODAY WILL LIKELY BE THE HIGHEST WE WILL SEE THROUGH
THE NEXT WEEK...WITH HIGHS TOPPING OUT IN THE 70S. LOWS TONIGHT
WILL SNEAK INTO THE UPPER 30S ACROSS WEST CENTRAL MN....WITH 40S
ELSEWHERE.

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 405 AM CDT SUN MAY 17 2015

THE EXTENDED PERIOD CAN BE CHARACTERIZED AS MAINLY DRY AND
UNSEASONABLY COOL FOR AT LEAST THE FIRST TWO DAYS /MONDAY AND
TUESDAY/...WITH POSSIBLY MORE PRECIPITATION BY NEXT WEEKEND.

MONDAY MORNING THE INTENSE SFC LOW WILL BEGIN TO FILL AND MOVE OFF
TO THE NORTHEAST ACROSS THE NORTHERN GREAT LAKES. WRAP AROUND
MOISTURE WILL BE CONFINED TO CENTRAL/NORTHERN MN WHERE THE HIGHEST
POPS WILL BE LOCATED. HOWEVER...SOME SPRINKLES COULD MOVE INTO
SOUTHERN MN/WC WI DUE TO COLD AIR ALOFT AND RESIDUAL MOISTURE NEAR
THE AREA.

STANDARD 85H/92H TEMPERATURE ANOMALIES ARE 2-4 BLW NORMAL BY
MONDAY/MONDAY NIGHT WHICH TRANSLATES TO SFC TEMPS NEARLY 20-30
DEGREES BELOW NORMAL. EVEN THE GEFS/NAEFS MEAN 85H TEMPS RETURN
INTERVAL BASED ON CLIMATOLOGY /1985 - 2012/ ARE ONCE EVERY 10 YEARS
FOR THESE TYPE OF TEMPS FOR MID MAY. EVEN SOME AREAS IN THE
NORTHERN PLAINS ARE OUTSIDE CLIMATOLOGY NORMS WHICH MEANS SOME
RECORD LOWS ARE POSSIBLE EARLY NEXT WEEK BASED ON THE AMOUNT OF
CLOUD COVER AND SFC WINDS.

THE MEAN UPPER FLOW WILL BE WEST/NW ACROSS THE UPPER MIDWEST
AS AN UPPER RIDGE HOLDS ACROSS WESTERN CANADA...AND AN UPPER LOW
BUILDS SOUTHWARD ACROSS HUDSON BAY BY MIDWEEK. THE MEAN UPPER FLOW
ACROSS THE WESTERN AND SOUTHERN PART OF THE CONUS WILL BE MORE
PROGRESSIVE WITH SEVERAL STORM SYSTEMS AFFECTING THAT REGION. NOT
UNTIL LATE IN THE EXTENDED PERIOD...POSSIBLY AS LATE AS
SATURDAY/SUNDAY WILL WE GET INTO A MORE PROGRESSIVE FLOW FROM
THE SW AS THE UPPER RIDGE BREAKS DOWN IN WESTERN CANADA AND AN UPPER
LOW MOVES INLAND INTO THE SW CONUS. TEMPS WILL SLOWLY MODERATE BY
THE END OF THE WEEK WITH 60S/70S MOVING BACK INTO THE REGION.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 125 PM CDT SUN MAY 17 2015

LIKE THE IDEA OF THE HRRR...WITH WIDESPREAD SHOWERS AND
THUNDERSTORMS DEVELOPING THIS AFTERNOON AS THE STACKED LOW MOVES
THROUGH MN WITH MARGINAL INSTABILITY BUT VIRTUALLY NO CIN. DECIDED
TO CONTINUE TREND OF HANDLING THIS SCENARIO WITH VC GROUPS AND
EXTENDED TEMPO GROUPS FOR THUNDER. HAVE HIGH CONFIDENCE IN STORMS
OCCURRING...JUST LOW CONFIDENCE ON TIMING/TRACKS OF THE NUMEROUS
STORMS THAT ARE EXPECTED. AS WE GET BEHIND THE COLD FRONT...LOW
STRATUS BACK OVER THE DAKOTAS WILL SWING THROUGH...WITH TIMING ON
ITS ARRIVAL NOT TOO DIFFERENT BETWEEN THE HRRR/SREF/NAM/LAMP...SO
MAIN ISSUE WITH THAT IS MORE HOW LOW WILL IT BE AS OPPOSED TO WHEN
WILL THOSE CLOUDS GET TO EACH AIRPORT. MAIN CHANGE MADE TO THE
PREVIOUS TAF WAS TO GO WITH MORE WINDS GIVEN STRENGTH OF MIXED
LAYER WINDS ON NAM SOUNDINGS...WOULD NOT BE SURPRISED TO SEE SOME
WIND GUSTS IN WRN MN TONIGHT THROUGH MON MORNING GET INTO THE 40S
KTS.

KMSP...ALREADY SEEING SHOWERS BUBBLE UP AT 18Z...AND THINKING
THIS THEME OF SCT SHOWERS/STORMS WILL BE WITH US THROUGH ABOUT 1Z.
TEMPO GROUP FOR THUNDER IS BASED ON WHEN THE HRRR BRINGS THE
GREATEST COVERAGE OF STORMS THROUGH. ALSO HAVE HIGH CONFIDENCE IN
MVFR CIGS RETURNING TONIGHT. THOUGH HAVE KEPT CIGS ABOVE 017...MAY
CIGS GET DOWN BETWEEN 010-015 DURING THE MORNING ON MONDAY. WINDS
COULD ALSO BE PROBLEMATIC MONDAY MORNING...WITH STRONG CROSS
WINDS EXPECTED IN THE EARLY MORNING BEFORE WINDS CONTINUE TO VEER
MORE TOWARD A 300 DIRECTION IN THE AFTERNOON.

/OUTLOOK FOR KMSP/
TUE...MVFR CIGS EARLY. WINDS N AT 10 KTS.
WED...VFR. WINDS NNE 5 KTS.
THU...VFR. WINDS NNW 5 KTS.

&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&

$$

SHORT TERM...LS
LONG TERM...JLT
AVIATION...MPG



AREA FORECAST DISCUSSION

NWS OMAHA/VALLEY NE

 1156 PM CDT SAT MAY 16 2015

.SHORT TERM...(TONIGHT THROUGH TUESDAY)
ISSUED AT 332 PM CDT SAT MAY 16 2015

SEVERE POTENTIAL TONIGHT REMAINS THE PRIMARY FORECAST CONCERN.
SCATTERED CONVECTION SUNDAY FOLLOWED BY COOLER TEMPERATURES TO BEGIN
THE WORK WEEK ARE SECONDARY CONCERNS.

18Z SOUNDING AT KOAX SHOWED ALMOST 1500 J/KG OF SURFACE-BASED
CAPE...WHICH IS MUCH LOWER THAN THE 2500 J/KG SHOWN BY OPERATIONAL
RAP ANALYSIS OBSERVED ON SPC MESOANALYSIS PAGE. SOUNDING ALSO SHOWED
ALMOST 50 J/KG OF CONVECTIVE INHIBITION. HOWEVER AXIS OF HIGHEST
CAPE NEAR OUR CWA DEPICTED BY RAP STILL LOOKS GOOD STRETCHING FROM
EASTERN SOUTH DAKOTA INTO WESTERN IOWA WHERE AVERAGE TEMPS AND DEW
POINTS WERE IN THE UPPER 70S AND UPPER 60S. EXPERIMENTAL HRRR
SUGGESTS A FEW STORMS WILL FIRE THIS AFTERNOON FROM SOUTHEAST SOUTH
DAKOTA INTO EASTERN NEBRASKA ON WESTERN SIDE OF INSTABILITY
GRADIENT...AND ALREADY ARE SEEING THE START OF THAT CONVECTION IN
SOUTH DAKOTA AND NEAR THE OMAHA METRO. THESE STORM SHOULD CONTINUE
TO MOVE OFF TO THE NORTHEAST RATHER QUICKLY...AND COULD SEE A
WIND/HAIL EVENT BEFORE EXITING OUR CWA LATE THIS AFTERNOON.

ATTENTION THEN TURNS TO POTENTIALLY MORE WIDESPREAD SEVERE IGNITING
WELL TO OUR SOUTHWEST IN THE HIGHS PLAINS FROM WESTERN NEBRASKA INTO
THE TEXAS PANHANDLE. HI-RES MODELS ALL HAVE SOME VARIATION IN THIS
CONVECTION...AND SPREAD IT INTO SOUTHEAST NEBRASKA LATER THIS
EVENING. WHAT KIND OF ATMOSPHERE WILL BE AVAILABLE FOR THOSE STORMS
IS STILL IN QUESTION...MAINLY DUE TO ON-GOING STORMS IN CENTRAL
KANSAS INTO NORTH CENTRAL OKLAHOMA. THE MOST LIKELY SCENARIO BASED
ON LATEST HRRR AND RAP IS SOME OF THE KANSAS CONVECTION WILL TRACK
NORTHEAST INTO EASTERN NEBRASKA LATE THIS AFTERNOON THEN EXIT TO THE
EAST THIS EVENING. GIVEN CURRENT INSTABILITY AND SHEAR...ROTATING
STORMS ARE LIKELY WITH AT LEAST SOME HAIL THREAT AND MOST NOTABLY
WIND. TORNADOES ARE STILL A THREAT AS WELL IF FORECAST STORM-
RELATIVE 0-1KM HELICITY NEAR 150 M2/S2 IS REALIZED. MODELS DEPICT
THIS AREA OF CONVECTION WILL BOW OUT ACROSS WESTERN IOWA BEFORE
EXITING TO OUR EAST.

THEN SECONDARY SURGE OF STORMS IS SLATED TO RACE NORTHEAST FROM
OKLAHOMA PANHANDLE AND ENTER SOUTHEAST NEBRASKA AT MID TO LATE
EVENING. SOME RECOVERY IN AIRMASS IS LIKELY AFTER EARLIER STORMS. AN
INCREASE IN LOW LEVEL JET TO NEAR 50KT IS LIKELY AS INCREASINGLY
DIFFLUENT MID LEVEL FLOW OVERSPREADS THE PLAINS. SO LATER-EVENING
STORMS WILL STILL HAVE VIGOROUS WIND FIELDS TO PLAY WITH...
SUPPORTING AT LEAST SOME TORNADO AND WIND THREAT PAST DARK. TREND IN
HOURLY UPDATES OF HRRR FORECASTS HAS BEEN FOR NORTHERNMOST SEVERE
STORMS TO ONLY GRAZE FAR SOUTHEAST NEBRASKA IN THE 03Z TO 06Z
TIMEFRAME. SO WILL KEEP A CLOSE EYE ON IF THIS TREND CONTINUES.

WHILE SECOND LINE OF STORMS MOVES EAST OF OUR CWA AFTER
MIDNIGHT...MORE SHOWERS/STORMS ARE FORECAST TO DEVELOP IN WESTERN
NEBRASKA AND TRACK INTO NORTHEAST NEBRASKA OVERNIGHT AS UPPER LOW
MOVES INTO THE NORTHERN PLAINS. A WAVE ROTATING AROUND THIS FEATURE
WILL LIKELY IGNITE SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS MUCH
OF SUNDAY IN SOUTH DAKOTA AND NORTHERN NEBRASKA. GFS SUGGESTS UP TO
1000 J/KG OF SURFACE-BASED CAPE WILL BE AVAILABLE FOR THIS ACTIVITY
INTO THE AFTERNOON.

AFTER WAVE PASSES SUNDAY AFTERNOON...STRONG COLD ADVECTION WILL
OVERSPREAD OUR AREA...DROPPING 850 TEMPERATURES TO BELOW 0C ON
MONDAY IN OUR NORTH. COULD SEE A PASSING SHOWER ALONG THIS COLD PUSH
SUNDAY NIGHT...BUT THE MAIN WEATHER STORY WILL BE COOLER AND DRIER
AIR BEING PUSHED INTO THE REGION ON BRISK NORTHWEST WINDS MONDAY.
HIGHS IN THE LOWER 60S SHOULD BE ALL WE CAN MUSTER THEN. THE COOL
WEATHER CONTINUES INTO TUESDAY WHEN SURFACE HIGH PRESSURE SETTLES
INTO THE REGION. COULD SEE SUB-40 LOWS IN MANY AREAS TUESDAY MORNING.

.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 332 PM CDT SAT MAY 16 2015

MID LEVEL FLOW PATTERN WILL RELOAD AS ANOTHER UPPER LOW SETTLES INTO
THE SOUTHWEST STATES AT MID WEEK ON HEELS OF EXITING NORTHERN PLAINS
LOW. THIS WILL BRING GENERALLY SOUTHWEST FLOW OVER THE MIDDLE OF THE
COUNTRY...WITH A POTENT WAVE EJECTING INTO THE PLAINS ON WEDNESDAY.
THAT WAVE WILL BRING OUR NEXT CHANCE FOR SHOWERS AND THUNDERSTORMS
BEGINNING TUESDAY NIGHT BEFORE EXITING WEDNESDAY NIGHT. MOISTURE
RETURN LOOKS MINIMAL...SO SEVERE STORMS APPEAR UNLIKELY DESPITE THE
CALENDAR SAYING WE ARE IN MID TO LATE MAY.

SOME WEAK RIDGING BEHIND EXITING WAVE SUGGESTS RAIN CHANCES WILL BE
AT A MINIMUM TO END THE WEEK...BUT SOUTHWESTERN TROUGH AXIS BEGINS
LIFTING TOWARD THE PLAINS BY SATURDAY. WILL BRING STORM CHANCES BACK
INTO THE FORECAST THEN...BUT DETAILS WILL HAVE TO BE WORKED OUT WITH
TIME ON DEGREE OF POTENTIAL SEVERE RISK.

&&

.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1142 PM CDT SAT MAY 16 2015

REGIONAL RADAR SHOWING PCPN OVER ERN GRADUALLY SHIFTING NEWD INTO
WRN IA...AND EXPECT LINGERING ACTIVITY AT KOMA/KLNK TO COME TO A
CLOSE WITHIN A COUPLE HOURS. OTHERWISE VFR CONDITIONS WILL PREVAIL
THRU THE FCST PD.

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&

$$

SHORT TERM...DERGAN
LONG TERM...DERGAN
AVIATION...DEE



AREA FORECAST DISCUSSION...UPDATED

NWS ALBUQUERQUE NM

 1140 PM MDT SAT MAY 16 2015

.AVIATION...
06Z TAF CYCLE
A FEW SPOT SH STILL EXIST BUT WILL QUICKLY COME TO AN END THROUGH
VERY EARLY MORNING ON SUNDAY. VERY LITTLE IMPACT OTHER THAN MTN
TOP OBSCD DUE TO THE PASSING SH. SATELLITE SHOWS ANOTHER BATCH OF
MID/HIGHER LEVEL CLOUDS MAKING THEIR WAY TOWARDS THE FORECAST
AREA. THEY SHOULD ARRIVE LATE TONIGHT AND TRACK OVER THE FORECAST
AREA THROUGH EARLY/MID AFTERNOON. THINKING THAT THERE IS A LESS
LIKELY CHANCE FOR FG/BR DEVELOPMENT AT WESTERN/CENTRAL TERMINAL
SITES SO TOOK OUT MENTION OF VCFG. THIS IS SUPPORTED BY THE LATEST
MODEL GUIDANCE. OTHERWISE VFR CONDITIONS PRETTY MUCH AREAWIDE NEXT
24 HRS. WIND GUSTS WONT BE NEARLY AS STRONG SUNDAY COMPARED TO THE
PREVIOUS FEW DAYS.

50

&&

.PREV DISCUSSION...325 PM MDT SAT MAY 16 2015...
.SYNOPSIS...
PRECIPITATION AND WINDS OVERALL SHOULD DECREASE TONIGHT...WITH QUIET
AND WARMER WEATHER SUNDAY. ANOTHER FRONT AND STORM SYSTEM WILL
COLLIDE BY MONDAY NIGHT AND TUESDAY...WITH ANOTHER WET AND COOLER
PERIOD...ESPECIALLY FOR LOCALES EXTENDING FROM THE RIO GRANDE VALLEY
EASTWARD ACROSS THE EASTERN PLAINS. DRYING EXPECTED THEREAFTER WITH
SOME WARMING BUT SOME STORMS WILL STILL BE POSSIBLE ACROSS AT LEAST
OVER THE FAR EASTERN PLAINS AND NORTHERN MOUNTAINS THE END OF NEXT
WEEK.

&&

.DISCUSSION...
PRECIPITATION AND WINDS OVERALL SHOULD DECREASE OVERNIGHT...BUT WITH
SOME POSSIBLE EXCEPTIONS.  WIND ADVY SPOTTY AT BEST THIS AFTERNOON
AND STRONGEST GUSTS APPEAR TO HAVE BEEN CONVECTION
RELATED...HOWEVER...H7 WINDS INCREASE OVERNIGHT OVER PARTS OF THE
NORTHEAST AS THE UPPER LOW/TROF SWINGS OUT INTO THE PLAINS
STATES...SO WILL KEEP THE NPW GOING. WILL ALSO KEEP THE CURRENT WSW
AS IS...WITH GFS/NAM NOT INDICATING MUCH SNOW AFTER 00Z. THE HRRR ON
THE OTHER HAND...KEEPS SOME SNOW GOING OVER THE NRN SANGRE DE CRISTO
MTS...AND THE FORECAST MOIST W-NWLY BOUNDARY LAYER WINDS INTO THE
SANGRES COULD CONTINUE TO ACCUMULATE SOME SNOW INTO THE LATE
EVENING. ARRGH...WILL HAVE TO CONTINUE TO MONITOR...BUT GRIDS HAVE
ANOTHER 1 TO 3 INCHES IN THIS AREA TONIGHT...ALTHOUGH THAT WOULD BE
UNDERDONE IF HRRR IS RIGHT. BUT NO MODEL SEEMS TO BE DOING THAT WELL
TODAY.

DRIER AND WARMER SUNDAY INTO MONDAY. THEN ANOTHER WETTER AND COOLER
PERIOD MONDAY NIGHT THROUGH TUESDAY AS ANOTHER SYSTEM COMING FROM
THE WEST AND A FRONT FROM THE EAST COLLIDE TO PRODUCE WIDESPREAD
PRECIPITATION. TRIMMED DOWN POPULATED QPF WHICH TOTALED A LARGE
SWATH OF A COUPLE OF INCHES JUST MONDAY NIGHT ALONG THE CENTRAL MT
CHAIN TO THE PECOS VALLEY. BUT SOME GENEROUS AMOUNTS POSSIBLE
TUESDAY AS WELL AS THE UPPER SYSTEM SWINGS OVER NE NM. H7 TEMPS NOT
AS COLD AS WITH PRESENT SYSTEM SO NOT ANTICIPATING THE LOWER SNOW
LEVELS THAT HAVE BEEN OBSERVED TODAY.

LOTS OF VARIATION MID TO LATE NEXT WEEK...THE GFS IS DRIER AND WINDY
WHILE THE ECMWF IS WETTER THANKS TO A FRONT ON FRIDAY...SURPRISE. IN
ANY EVENT...THE UNSETTLED WEATHER PATTERN APPEARS TO CONTINUE INTO
THE MEMORIAL DAY WEEKEND.

&&

.FIRE WEATHER...

NO WIDESPREAD FIRE WEATHER CONCERNS THROUGH THE FORECAST PERIOD AS
THE WEATHER PATTERN CONTINUES TO FAVOR UNSETTLED...ACTIVE WEATHER
AND SEASONABLY COOLER THAN NORMAL TEMPERATURES.

CURRENT UPPER LEVEL TROUGH IS CROSSING NM THIS PM AND WILL SHIFT TO
THE EAST TONIGHT. SHOWERS AND THUNDERSTORMS WILL CONTINUE THROUGH
THE EVENING HOURS...MAINLY NORTH OF I 40. SHOWERS MAY LINGER OVER
THE NORTH LATE TONIGHT. RH RECOVERIES WILL BE GOOD TO EXCELLENT.

A MAINLY DRY DAY IS IN STORE SUNDAY AS A WEAK UPPER LEVEL RIDGE
MOVES OVER. DESPITE THE RIDGE...HIGH TEMPERATURES REMAIN BELOW
AVERAGE FOR MID MAY. MODELS INDICATING RESIDUAL MOISTURE WILL
COMBINE WITH DAYTIME HEATING TO PRODUCE A FEW SHOWERS AND MAYBE
THUNDERSTORMS OVER THE NORTHERN MOUNTAINS.

A BACK DOOR COLD FRONT WILL DROP SOUTH INTO THE NORTHEAST EAST
SUNDAY NIGHT. IT WILL STALL MONDAY BEFORE RACING SOUTH AND WEST
MONDAY NIGHT. STRONG EAST WINDS INTO THE RIO GRANDE VALLEY ARE
POSSIBLE. MEANWHILE THE NEXT UPPER LEVEL TROUGH WILL BE APPROACHING
MONDAY THEN SWEEP ACROSS THE STATE MONDAY NIGHT INTO TUESDAY. THE
COMBINATION OF LOW LEVEL MOISTURE BEHIND THE FRONT...INSTABILITY
FROM THE UPPER TROUGH...AND DEEP MOISTURE GETTING DRAWN NORTHWEST
INTO NM FROM TX WILL RESULT IN A SIGNIFICANT RAIN EVENT FOR MUCH OF
THE FORECAST AREA...WITH THE LEAST FAVORED AREA THE SOUTHWEST AND
THE MOST FAVORED AREA ALL OF THE EAST. ALL THE MODELS HAVE A FAIRLY
WIDESPREAD...SOAKING RAIN EVENT WITH ONE TO TWO INCH RAIN AMOUNTS
FOR THE EASTERN PLAINS AND LOCALLY UP TO THREE INCHES IN THE MONDAY
NIGHT THROUGH TUESDAY TIME PERIODS.

YET ANOTHER STORM WILL BE ORGANIZING OFF THE CA COAST LATER NEXT
WEEK. THE FAR EASTERN PLAINS WILL BE UNDER THE GUN FOR SHOWERS AND
STORMS WEDNESDAY INTO FRIDAY. A DRY LINE WILL WOBBLE BACK WEST AT
NIGHT AND TO THE EAST DURING THE DAY. ELSEWHERE SHOULD BE MOSTLY
DRY. ALL AREAS WILL REMAIN BELOW NORMAL. WINDS WILL BE ON THE
INCREASE NEXT FRIDAY AND SATURDAY. BRIEF CRITICAL FIRE WEATHER
CONDITIONS ARE NOT OUT OF THE QUESTION OVER THE SOUTHERN PORTION
OF THE MIDDLE RIO GRANDE VALLEY FRIDAY AFTERNOON.

A PORTION OF THE ABOVE MENTIONED STORM WILL CROSS NM SATURDAY WHILE
ANOTHER PORTION HANGS BACK OVER UT AND AZ. THIS LAZY TROUGH WILL
INCH ITS WAY EAST WHILE KEEPING SHOWERS AND STORMS IN THE FORECAST
FOR THE NORTH AND EAST LATE NEXT WEEKEND INTO EARLY THE FOLLOWING
WEEK. 40

&&

.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$








AREA FORECAST DISCUSSION

NWS BINGHAMTON NY

 836 PM EDT MON MAY 18 2015

.SYNOPSIS...
WARM AND MUGGY CONDITIONS WILL CONTINUE THROUGH THE NIGHT WITH
ADDITIONAL SHOWERS AND THUNDERSTORMS THROUGH SUNRISE. A COLD
FRONT WILL SWEEP THROUGH THE AREA BY EARLY AFTERNOON TUESDAY WITH
MORE SHOWERS AND STORMS POSSIBLE. MUCH COOLER WEATHER WILL FOLLOW
BEHIND THE FRONT FOR THE MIDDLE AND LATER PART OF THE WEEK.

&&

.NEAR TERM /THROUGH TUESDAY/...
500 MB HEIGHT FALLS WERE OCCURRING ACROSS THE REGION THIS EVENING
SUPPORTED BY MODEST MID-UPR LEVEL DIVERGENCE ALOFT. A SERIES OF
WEAK MID-LVL IMPULSES ARE PROGGED TO CONTINUE TO SLIDE FROM THE
OHIO VALLEY OFF TO THE NORTHEAST ACROSS WESTERN...THEN CENTRAL NEW
YORK AS THE ENTIRE COMPLEX SYSTEM DRIFTS EASTWARD. MODERATE SFC
BASED INSTABILITY WILL WANE WITH THE LOSS OF SOLAR HEATING...
HOWEVER...ANOMALOUS MOISTURE IN THE BOUNDARY LAYER WILL REMAIN
AND CONTRIBUTE TO A LINGERING INSTABILITY AXIS ACROSS CNTRL NY AND
NRN PA THROUGH THE NIGHT. FORECAST WAS GENERALLY IN GOOD SHAPE TO
ACCOUNT FOR OCCASIONAL ROUNDS OF TSRA THROUGH THE NIGHT. GFS/GGEM
AND HRRR MODELS DO SUGGEST A POTENTIAL ENHANCEMENT OF HEAVIER
STORMS FOCUSING AGAIN FROM SOUTH CNTRL PA INTO CNTRL NY BETWEEN
03Z-09Z WHICH MATCHES WELL WITH THE INSTABILTY AXIS. WE ARE NO
LONGER THINKING ANY ORGANIZED SEVERE WEATHER OVERNIGHT...BUT HEAVY
RAIN POTENTIAL DOES REMAIN. THE QUESTION BEING IS THERE ENOUGH
EVIDENCE AND CONFIDENCE TO HOIST A FLASH FLOOD WATCH AS THERE HAVE
BEEN LOCALIZED AREAS OF EXTREME RAINFALL TODAY...ESPECIALLY HERE
IN THE HOME COUNTY.

RIGHT NOW...WE THINK THE CONVECTIVE STRENGTH WILL BE WEAKER THAN
EARLIER TODAY GIVEN THE LOSS OF BUOYANCY AND REALLY NO SIGNIFICANT
PUNCH TO THE DYNAMIC FORCING. CAN`T TOTALLY RULE OUT SOME HEAVIER
DOWNPOURS AND POTENTIAL OVERWHELMING OF STORM DRAINS IN ANY
DEVELOPED TOWN OR CITY THAT MIGHT GET A SLOW MOVING STORM...BUT
WILL DEAL WITH THAT ON THE SHORT TERM SHOULD IT UNFOLD.

OTHERWISE...JUST MINOR CHANGES THIS EVENING TO ADJUST FOR TEMPS IN
THE MARINE LAYER TO OUR EAST PUSHING WESTWARD.

COLD FRONT THEN SWEEPS INTO AND THROUGH THE REGION ON TUESDAY
MORNING WITH IMPROVING AND COOLER WEATHER DURING THE AFTERNOON.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
QUIET WEATHER IS EXPECTED THROUGH THIS PERIOD WITH MUCH LOWER
TEMPERATURES BEHIND THE COLD FRONT. CANADIAN HIGH PRESSURE WILL
BUILD ACROSS THE GREAT LAKES TOWARD THE MID-ATLANTIC WEDNESDAY
INTO THURSDAY. LOW PRESSURE IS FORECAST TO TRACK FROM THE
TENNESSEE VALLEY TOWARD THE CAROLINAS WEDNESDAY NIGHT INTO
THURSDAY WITH ASSOCIATED RAIN WELL TO OUR SOUTH. GENERALLY WENT
WITH A BLEND OF MAV/MET GUIDANCE FOR TEMPERATURES WEDNESDAY AND
THURSDAY WHICH YIELDED UNSEASONABLY COOL HIGHS IN THE MID 50S TO
MID 60S ON WEDNESDAY... WARMING A BIT INTO THE 60S ON THURSDAY.
LOWS WEDNESDAY NIGHT WILL RANGE FROM THE MID 30S TO MID 40S WITH A
TOUCH OF FROST NOT OUT OF THE QUESTION IN NORMALLY COOLER
LOCATIONS.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
QUIET PD FOR THE XTNDD. SCNDRY FNT APRCHS THE AREA ON FRI AND MGT
GENERATE A FEW SHWRS OVER THE NRN AREAS WITH PEAK HTG. HGTS BLDS
AGAIN AS SFC HIPRES BLDS IN FOR THE WEEKEND SO XPCT DRY WEATHER
INTO SUNDAY. WITH THE TROFINESS ALOFT IN THE PD...TEMPS WILL BE A
BIT COOLER THAN NRML DESPITE THE DAYTIME SUN.

&&

.AVIATION /01Z TUESDAY THROUGH SATURDAY/...
APPROACHING UPPER LEVEL TROF AND ASSOCIATED SFC COLD FRONT WILL
APPROACH THE REGION OVERNIGHT BRINGING WIDESPREAD SHOWERS AND CIG
RESTRICTIONS. IN GENERAL, WIDESPREAD LOW MVFR CONDITIONS ARE
EXPECTED LATER THIS EVENING WITH CIGS AT KAVP/BGM DROPPING TO IFR
DUE TO MARINE LAYER. FRONTAL PASSAGE WILL OCCUR AROUND 15Z WITH
CONDITIONS GRADUALLY IMPROVING TO VFR BY MIDDAY TO EARLY
AFTERNOON.

S/SE WINDS OVERNIGHT AROUND 5-10 KNOTS BECOMING SOUTHWEST AROUND
MID MORNING AT 10 KNOTS THEN NW BY AFTERNOON AT 10-15 KNOTS WITH
GUSTS AROUND 25 KNOTS.

.OUTLOOK...

TUE NGT-SAT...MAINLY VFR.

&&

.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.

&&

$$
SYNOPSIS...JAB
NEAR TERM...JAB
SHORT TERM...MSE
LONG TERM...DGM
AVIATION...RRM



AREA FORECAST DISCUSSION

NWS BISMARCK ND

 134 PM CDT SUN MAY 17 2015

.UPDATE...
ISSUED AT 1256 PM CDT SUN MAY 17 2015

MIX OF RAIN AND SNOW IS OCCURRING ACROSS THE NORTH BUT WEB
CAMERAS SHOW LITTLE ACCUMULATIONS SHOWING UP ON GRASSY AREAS AS OF
1 PM CDT. WILL CONTINUE THE WINTER WEATHER ADVISORY START TIME
THIS EVENING. OTHERWISE MODERATE TO SOMETIMES HEAVY RAINFALL
CONTINUES ACROSS EAST CENTRAL NORTH DAKOTA. THE CENTER OF MID
LEVEL CIRCULATION IS SEEN IN THE PRECIPITATION VERY WELL ON RADAR
JUST SOUTH OF ABERDEEN. AS THIS FEATURE MOVE NORTHEAST SHOULD SEE
THE RAIN AREA TRANSLATE SLOWLY EAST FOR THE REMAINDER OF THE
AFTERNOON. CONTINUE THE AREAL FLOOD ADVISORY FROM JAMESTOWN SOUTH
TO THE SOUTH DAKOTA BORDER.

UPDATE ISSUED AT 1052 AM CDT SUN MAY 17 2015

EVOLVING CAPE FORECAST FROM NAM AND HRRR SUGGEST THE THUNDERSTORMS
MAY BECOME MUCH LESS PREVALENT BY THIS AFTERNOON. ADJUSTED TO
SHOWERS. EXPANDED THE WIND ADVISORY WEST TO INCLUDE CENTRAL AND
NORTH CENTRAL NORTH DAKOTA.

UPDATE ISSUED AT 643 AM CDT SUN MAY 17 2015

FORECAST ON TRACK WITH ONLY A COUPLE MINOR ADJUSTMENTS TO POPS
BASED ON CURRENT RADAR TRENDS. WATER VAPOR IMAGERY SHOWS BROAD
CLOSED UPPER LOW FROM EASTERN MONTANA TO EASTERN NEBRASKA WITH
WELL DEFINED CIRCULATION MOVING INTO EASTERN SOUTH DAKOTA. THIS IS
ASSOCIATED WITH A 100KT JET STREAK THAT IS NOSING INTO
SOUTHEASTERN NORTH DAKOTA...SUPPORTING AN EXPANDING AREA OF
SHRA/TSRA. EXPECT THESE TRENDS TO CONTINUE AS UPSTREAM RADARS SHOW
WIDESPREAD SHOWERS AND THUNDERSTORMS CONTINUING TO APPROACH OUR
SOUTHEASTERN AREAS FROM SOUTH DAKOTA.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 415 AM CDT SUN MAY 17 2015

CONCERNS THIS FORECAST PERIOD INCLUDE ANOTHER DAY OF HEAVY RAIN FOR
CENTRAL NORTH DAKOTA. STRONG NORTH WINDS AND WIND ADVISORY CRITERIA
EXPECTED FOR EASTERN PARTS OF CENTRAL NORTH DAKOTA. THEN
ATTENTION TURNS TO RAIN CHANGING TO SNOW THIS AFTERNOON AND
TONIGHT...WITH SNOW ACCUMULATIONS EXPECTED AND A WINTER WEATHER
ADVISORY FOR NORTH CENTRAL COUNTIES TONIGHT.

THE UPPER LEVEL LOW WAS OVER EASTERN MONTANA AND WYOMING. IT IS
FORECAST TO MOVE/DEVELOP SOUTHEAST QUICKLY THIS MORNING AS AN
INTENSE UPPER LEVEL SHORTWAVE/IMPULSE MOVES NORTHWARD FROM THE
SOUTHERN PLAINS INTO THE EASTERN DAKOTAS. THIS SHOULD BE THE ONSET
OF HEAVY RAIN OVER EASTERN PORTIONS OF CENTRAL NORTH DAKOTA TODAY.
IN ADDITION TO THE RAINS THAT FELL ON SATURDAY...ANOTHER INCH OR TWO
OF RAINFALL CAN BE EXPECTED ALONG AND EAST OF A LINE FROM MINOT TO
BISMARCK...WITH 0.25 TO 1 INCH WEST OF THIS LINE.

THIS STRONG UPPER LEVEL LOW WILL BE ASSOCIATED WITH DEEPENING OF THE
SURFACE LOW THAT IS CURRENTLY CENTERED OVER CENTRAL SOUTH DAKOTA.
THIS LOW WILL STRENGTHEN AS IT MOVES NORTHEAST TOWARDS THE ND/SD/MN
BORDER BY THIS EVENING. NORTH WINDS WILL INCREASE TODAY TO 25 TO 35
MPH ACROSS WESTERN AND CENTRAL NORTH DAKOTA. THE STRONGEST WINDS OF
30 TO 35 MPH WITH GUSTS TO 45 MPH SHOULD OCCUR FROM BOTTINEAU AND
THE TURTLE MOUNTAINS SOUTHWARD ALONG THE JAMES RIVER VALLEY TO
MCINTOSH AND DICKEY COUNTIES.

THE NORTH WINDS WILL USHER IN MUCH COOLER AIR...AND RAIN WILL MIX
WITH AND CHANGE TO SNOW THIS AFTERNOON NORTHWEST AND NORTH CENTRAL.
THE CHANGEOVER TO SNOW WILL PROGRESS SOUTHEASTWARD TONIGHT AND SNOW
ACCUMULATIONS CAN BE EXPECTED OVER MUCH OF THE FORECAST AREA.
EXPECTING 3 TO 5 INCHES OVER MUCH OF THE NORTH CENTRAL...FROM
STANLEY AND KENMARE IN THE NORTHWEST...TO GARRISON...HARVEY...AND
CARRINGTON IN THE SOUTH...INCLUDING MINOT TO RUGBY AND THE TURTLE
MOUNTAINS. A WINTER WEATHER ADVISORY WILL BE ISSUED FOR THIS AREA.
LESSER AMOUNTS OF SNOW ACCUMULATION ARE EXPECTED TO THE SOUTH AND
WEST.

FREEZING TEMPERATURES IN THE MID 20S TO LOWER 30S WILL BE WIDESPREAD
ACROSS WESTERN AND CENTRAL NORTH DAKOTA.

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 415 AM CDT SUN MAY 17 2015

MONDAY MORNING WILL SEE LINGERING RAIN/SNOW SHOWERS AS THE DEEP LOW
PRESSURE SYSTEM REACHES THE GREAT LAKES REGION BY 18Z MON. HIGH
PRESSURE WILL SETTLE OVER THE NORTHERN PLAINS BEHIND THE
LOW...LEADING TO MOSTLY DRY CONDITIONS. IN ADDITION...TEMPERATURES
WILL SHOW A WARMING TREND WITH MAX TEMPS BACK INTO THE 60S BY
MIDWEEK. THE GREATEST WEATHER IMPACT WILL BE FROM FROST/FREEZE
CONDITIONS MONDAY NIGHT AND TUESDAY NIGHT. MONDAY NIGHT IS
EXPECTED TO BE THE COLDER OF THE TWO NIGHTS WITH LOWS REACHING THE
MID 20S.

GFS/ECMWF BRING AN UPPER LOW TO WYOMING BY EARLY
WEDNESDAY...ALTHOUGH PRECIP WITH THIS SYSTEM IS CONFINED TO
LOCATIONS TO OUR SOUTH. THE NEXT CHANCE OF PRECIP WOULD THEN BE NEXT
WEEKEND WITH GFS/ECMWF/ENSEMBLES SHOWING AN UPPER LEVEL TROUGH
ACROSS THE NORTH CENTRAL CONUS WITH SURFACE LOW TRACKING OVER THE
CENTRAL PLAINS.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1256 PM CDT SUN MAY 17 2015

LARGE STORM CREATING WIDESPREAD IFR CONDITIONS IN LOW CLOUDS...
RAIN...AND FOG. COOLER AIR ACROSS THE NORTH WILL CAUSE SNOW
ACROSS KMOT. CONDITIONS SLOWLY IMPROVING KISN AFTER 06Z.

&&

.HYDROLOGY...
ISSUED AT 415 AM CDT SUN MAY 17 2015

ANOTHER 1 OR 2 INCHES OF RAINFALL IS EXPECTED TODAY ALONG AND EAST
OF A LINE FROM MINOT TO BISMARCK. FLOODING IN LOW LYING AND POOR
DRAINAGE AREAS IS POSSIBLE.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 7 AM CDT
MONDAY FOR NDZ003>005-010>013-021>023-025.

WIND ADVISORY UNTIL 7 PM CDT THIS EVENING FOR NDZ003>005-011>013-
021>023-025.

WIND ADVISORY FROM 4 PM THIS AFTERNOON TO 7 AM CDT MONDAY FOR
NDZ036-037-046>048-050-051.

WIND ADVISORY UNTIL 7 AM CDT /6 AM MDT/ MONDAY FOR NDZ019-020-
034-035-042-045.

&&

$$

UPDATE...WAA
SHORT TERM...JV
LONG TERM...JNS
AVIATION...WAA
HYDROLOGY...JV




AREA FORECAST DISCUSSION

NWS BISMARCK ND

 1054 AM CDT SUN MAY 17 2015

.UPDATE...
ISSUED AT 1052 AM CDT SUN MAY 17 2015

EVOLVING CAPE FORECAST FROM NAM AND HRRR SUGGEST THE THUNDERSTORMS
MAY BECOME MUCH LESS PREVALENT BY THIS AFTERNOON. ADJUSTED TO
SHOWERS. EXPANDED THE WIND ADVISORY WEST TO INCLUDE CENTRAL AND
NORTH CENTRAL NORTH DAKOTA.

UPDATE ISSUED AT 643 AM CDT SUN MAY 17 2015

FORECAST ON TRACK WITH ONLY A COUPLE MINOR ADJUSTMENTS TO POPS
BASED ON CURRENT RADAR TRENDS. WATER VAPOR IMAGERY SHOWS BROAD
CLOSED UPPER LOW FROM EASTERN MONTANA TO EASTERN NEBRASKA WITH
WELL DEFINED CIRCULATION MOVING INTO EASTERN SOUTH DAKOTA. THIS IS
ASSOCIATED WITH A 100KT JET STREAK THAT IS NOSING INTO
SOUTHEASTERN NORTH DAKOTA...SUPPORTING AN EXPANDING AREA OF
SHRA/TSRA. EXPECT THESE TRENDS TO CONTINUE AS UPSTREAM RADARS SHOW
WIDESPREAD SHOWERS AND THUNDERSTORMS CONTINUING TO APPROACH OUR
SOUTHEASTERN AREAS FROM SOUTH DAKOTA.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 415 AM CDT SUN MAY 17 2015

CONCERNS THIS FORECAST PERIOD INCLUDE ANOTHER DAY OF HEAVY RAIN FOR
CENTRAL NORTH DAKOTA. STRONG NORTH WINDS AND WIND ADVISORY CRITERIA
EXPECTED FOR EASTERN PARTS OF CENTRAL NORTH DAKOTA. THEN
ATTENTION TURNS TO RAIN CHANGING TO SNOW THIS AFTERNOON AND
TONIGHT...WITH SNOW ACCUMULATIONS EXPECTED AND A WINTER WEATHER
ADVISORY FOR NORTH CENTRAL COUNTIES TONIGHT.

THE UPPER LEVEL LOW WAS OVER EASTERN MONTANA AND WYOMING. IT IS
FORECAST TO MOVE/DEVELOP SOUTHEAST QUICKLY THIS MORNING AS AN
INTENSE UPPER LEVEL SHORTWAVE/IMPULSE MOVES NORTHWARD FROM THE
SOUTHERN PLAINS INTO THE EASTERN DAKOTAS. THIS SHOULD BE THE ONSET
OF HEAVY RAIN OVER EASTERN PORTIONS OF CENTRAL NORTH DAKOTA TODAY.
IN ADDITION TO THE RAINS THAT FELL ON SATURDAY...ANOTHER INCH OR TWO
OF RAINFALL CAN BE EXPECTED ALONG AND EAST OF A LINE FROM MINOT TO
BISMARCK...WITH 0.25 TO 1 INCH WEST OF THIS LINE.

THIS STRONG UPPER LEVEL LOW WILL BE ASSOCIATED WITH DEEPENING OF THE
SURFACE LOW THAT IS CURRENTLY CENTERED OVER CENTRAL SOUTH DAKOTA.
THIS LOW WILL STRENGTHEN AS IT MOVES NORTHEAST TOWARDS THE ND/SD/MN
BORDER BY THIS EVENING. NORTH WINDS WILL INCREASE TODAY TO 25 TO 35
MPH ACROSS WESTERN AND CENTRAL NORTH DAKOTA. THE STRONGEST WINDS OF
30 TO 35 MPH WITH GUSTS TO 45 MPH SHOULD OCCUR FROM BOTTINEAU AND
THE TURTLE MOUNTAINS SOUTHWARD ALONG THE JAMES RIVER VALLEY TO
MCINTOSH AND DICKEY COUNTIES.

THE NORTH WINDS WILL USHER IN MUCH COOLER AIR...AND RAIN WILL MIX
WITH AND CHANGE TO SNOW THIS AFTERNOON NORTHWEST AND NORTH CENTRAL.
THE CHANGEOVER TO SNOW WILL PROGRESS SOUTHEASTWARD TONIGHT AND SNOW
ACCUMULATIONS CAN BE EXPECTED OVER MUCH OF THE FORECAST AREA.
EXPECTING 3 TO 5 INCHES OVER MUCH OF THE NORTH CENTRAL...FROM
STANLEY AND KENMARE IN THE NORTHWEST...TO GARRISON...HARVEY...AND
CARRINGTON IN THE SOUTH...INCLUDING MINOT TO RUGBY AND THE TURTLE
MOUNTAINS. A WINTER WEATHER ADVISORY WILL BE ISSUED FOR THIS AREA.
LESSER AMOUNTS OF SNOW ACCUMULATION ARE EXPECTED TO THE SOUTH AND
WEST.

FREEZING TEMPERATURES IN THE MID 20S TO LOWER 30S WILL BE WIDESPREAD
ACROSS WESTERN AND CENTRAL NORTH DAKOTA.

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 415 AM CDT SUN MAY 17 2015

MONDAY MORNING WILL SEE LINGERING RAIN/SNOW SHOWERS AS THE DEEP LOW
PRESSURE SYSTEM REACHES THE GREAT LAKES REGION BY 18Z MON. HIGH
PRESSURE WILL SETTLE OVER THE NORTHERN PLAINS BEHIND THE
LOW...LEADING TO MOSTLY DRY CONDITIONS. IN ADDITION...TEMPERATURES
WILL SHOW A WARMING TREND WITH MAX TEMPS BACK INTO THE 60S BY
MIDWEEK. THE GREATEST WEATHER IMPACT WILL BE FROM FROST/FREEZE
CONDITIONS MONDAY NIGHT AND TUESDAY NIGHT. MONDAY NIGHT IS
EXPECTED TO BE THE COLDER OF THE TWO NIGHTS WITH LOWS REACHING THE
MID 20S.

GFS/ECMWF BRING AN UPPER LOW TO WYOMING BY EARLY
WEDNESDAY...ALTHOUGH PRECIP WITH THIS SYSTEM IS CONFINED TO
LOCATIONS TO OUR SOUTH. THE NEXT CHANCE OF PRECIP WOULD THEN BE NEXT
WEEKEND WITH GFS/ECMWF/ENSEMBLES SHOWING AN UPPER LEVEL TROUGH
ACROSS THE NORTH CENTRAL CONUS WITH SURFACE LOW TRACKING OVER THE
CENTRAL PLAINS.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 643 AM CDT SUN MAY 17 2015

MVFR AND IFR CONDITIONS IN RAIN SHOWERS AND FOG THROUGH THE
AFTERNOON FOR THE TERMINALS. THUNDERSTORMS WITH HEAVY RAIN
EXPECTED AT KJMS/KBIS/KMOT. STRONG NORTH WINDS THROUGH THE TAF
PERIOD. NORTH WINDS WILL USHER IN COLD AIR AND RAIN CHANGES TO SNOW
AT KISN/KMOT AROUND 21Z...AND AT KDIK/KBIS AROUND 00Z...AND KJMS
AROUND 02Z. MAINLY IFR CONDITIONS IN SNOW AND FOG WITH STRONG WINDS
EXPECTED TONIGHT. KISN MAY SEE IMPROVING CONDITIONS TO VFR AFT 06Z.


&&

.HYDROLOGY...
ISSUED AT 415 AM CDT SUN MAY 17 2015

ANOTHER 1 OR 2 INCHES OF RAINFALL IS EXPECTED TODAY ALONG AND EAST
OF A LINE FROM MINOT TO BISMARCK. FLOODING IN LOW LYING AND POOR
DRAINAGE AREAS IS POSSIBLE.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 7 AM CDT
MONDAY FOR NDZ003>005-010>013-021>023-025.

WIND ADVISORY UNTIL 7 PM CDT THIS EVENING FOR NDZ003>005-011>013-
021>023-025.

WIND ADVISORY FROM 4 PM THIS AFTERNOON TO 7 AM CDT MONDAY FOR
NDZ036-037-046>048-050-051.

WIND ADVISORY UNTIL 7 AM CDT /6 AM MDT/ MONDAY FOR NDZ019-020-
034-035-042-045.

&&

$$

UPDATE...WAA
SHORT TERM...JV
LONG TERM...JNS
AVIATION...JV
HYDROLOGY...JV




AREA FORECAST DISCUSSION

NWS BISMARCK ND

 118 AM CDT SUN MAY 17 2015

.UPDATE...
ISSUED AT 117 AM CDT SUN MAY 17 2015

THIS UPDATE HAVE TAKEN MENTION OF HEAVY RAIN FOR THE REST OF THE
OVERNIGHT HOURS. SHOWERS AND THUNDERSTORM COVERAGE CONTINUED TO
DIMINISH IN SOUTHERN COUNTIES...WITH SCATTERED TO ISOLATED
SHOWERS/THUNDER IN THE JAMES RIVER BASIN TO THE TURTLE MOUNTAINS.
MORE SCATTERED TO WIDESPREAD RAIN SHOWERS OVER NORTHWEST AND NORTH
CENTRAL. THE UPPER LEVEL LOW OVER EASTERN MONTANA/WYOMING KEEPS A
SOUTHERLY FLOW ALOFT OVER THE DAKOTAS...WITH UPPER LEVEL ENERGY
IMPULSES MOVING NORTHWARD INTO NORTH DAKOTA. THROUGHOUT THE
OVERNIGHT HOURS THE UPPER LEVEL LOW IS FORECAST TO MOVE/DEVELOP
EASTWARD INTO CENTRAL SOUTH DAKOTA AND A MORE POTENT SURGE OF UPPER
LEVEL ENERGY IS FORECAST TO DEVELOP INTO EASTERN SOUTH DAKOTA AND
MOVE INTO EASTERN NORTH DAKOTA BEFORE DAYBREAK. THEREFORE STILL
EXPECTING ANOTHER ROUND OF SHOWERS TO BECOME MORE NUMEROUS MAINLY IN
THE JAMES RIVER VALLEY TO BISMARCK. OTHERWISE CURRENT WINDS AND
TEMPERATURES ARE ON TRACK.

UPDATE ISSUED AT 1044 PM CDT SAT MAY 16 2015

MAIN UPDATES HAVE BEEN TO SHOW THE DIMINISHING RAIN TREND FOR THE
NEXT SEVERAL HOURS AS PER THE HRRR. ADDITIONAL RAIN CHANCES ARRIVE
LATER TONIGHT INTO SUNDAY AS THE SURFACE LOW LIFTS TOWARDS EASTERN
NORTH DAKOTA.

&&

.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 340 PM CDT SAT MAY 16 2015

CONCERNS THIS FORECAST PERIOD INCLUDE SEVERE WEATHER POSSIBILITY
AND HEAVY RAIN. BY THE END OF THE SHORT TERM THE TRANSITION TO
MUCH COOLER WEATHER WITH SOME SNOW BEGINS TO BE SEEN.

AT 230 PM CDT...SURFACE LOW PRESSURE WAS CENTERED NEAR NORTHWEST
SOUTH DAKOTA WITH AN EAST WEST WARM FRONTAL BOUNDARY EXTENDED
ACROSS NORTH CENTRAL SOUTH DAKOTA. FLOW OVER THE WARM FRONT WAS
GENERATING SHOWERS AND SCATTERED THUNDERSTORMS FROM MOBRIDGE NORTH
TO NEAR MINOT AND NORTH TO THE CANADIAN BORDER.

CONCERNING SEVERE WEATHER POTENTIAL...AN 18Z KBIS SOUNDINGS WAS
CONDUCTED. HRRR FORECAST CAPE VALUES IN THE NEIGHBORHOOD OF 2000
ARE FORECAST TO POOL ACROSS SOUTH CENTRAL INTO SOUTHEAST NORTH
DAKOTA LATE THIS AFTERNOON AND EVENING. EXPECT THE SEVERE WEATHER
POTENTIAL TO EXTEND FROM BISMARCK EAST. TO THE WEST EXPECT MORE
ELEVATED THUNDERSTORMS.

LATE TONIGHT AND SUNDAY...AN UPPER LEVEL LOW SWINGS INTO EASTERN
SOUTH DAKOTA THEN TRACKS NORTHEAST AND SPREADS A LARGE AREA OF THE
RAINSHOWERS ACROSS THE EAST HALF OF THE STATE AND ESPECIALLY THE
JAMES RIVER VALLEY. ACROSS THE NORTH CENTRAL...COOLER AIR WILL
BEGIN A RAIN/SNOW CHANGE OVER. AS THE SURFACE LOW WRAPS UP NORTH
WINDS OF 25 TO 35 MPH WILL BE COMMON ACROSS CENTRAL NORTH DAKOTA
ON SUNDAY.

.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 340 PM CDT SAT MAY 16 2015

RAIN...SNOW AND COLD TEMPERATURES WILL HIGHLIGHT THE LONG TERM.

THE STORM IMPACTING NORTH DAKOTA SATURDAY AND SUNDAY WILL CONTINUE
TO INFLUENCE THE REGION THROUGH MONDAY. THE UPPER LEVEL LOW AND
SURFACE LOW WILL BECOME NEARLY VERTICALLY STACKED OVER EASTERN
NORTH DAKOTA SUNDAY NIGHT. THIS WILL LEAD TO ENHANCED LIFT AND
PRECIPITATION ACROSS PORTIONS OF CENTRAL AND EASTERN NORTH DAKOTA.
AS THE LOW PROPAGATES EASTWARD SUNDAY NIGHT INTO MONDAY...COLD
AIR WILL WRAP IN FROM THE NORTH. A STEADY RAIN WILL TRANSITION TO
SNOW FROM NORTHWEST TO SOUTHEAST SUNDAY NIGHT. IN ADDITION TO
TRANSITIONING RAIN TO SNOW...STRONG COLD AIR ADVECTION AND A STEEP
PRESSURE GRADIENT WILL PRODUCE GUSTY NORTHWEST WINDS AROUND 35
MPH.

THE 12 UTC GFS/ECMWF/SREF/GEM ARE IN GOOD AGREEMENT WITH RESPECT
TO PRECIPITATION AMOUNTS AND TEMPERATURES. THEREFORE...UTILIZED A
BLEND OF THE OPERATIONAL MODELS. THIS GENERALLY YIELDED LIQUID
PRECIPITATION AMOUNTS AROUND HALF AN INCH AND SNOW AMOUNTS AROUND
1 OR 2 INCHES SUNDAY NIGHT INTO MONDAY. WITH TEMPERATURES HOVERING
NEAR FREEZING...ROAD TEMPERATURES COULD BE WARM ENOUGH TO LIMIT
NEGATIVE IMPACTS TO TRAVEL. FROST AND TEMPERATURES IN THE 20S AND
LOW 30S ARE LIKELY SUNDAY NIGHT AND MONDAY NIGHT.

FOR NORTH DAKOTA THE REST OF THE LONG TERM APPEARS COOL AND
DRY...WITH FREQUENT RAIN CHANCES ACROSS SOUTH DAKOTA.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 117 AM CDT SUN MAY 17 2015

MVFR AND IFR CONDITIONS IN RAIN THROUGH MUCH OF THE TAF PERIOD.
NORTHERLY WINDS AT KISN/KMOT/KDIK/KBIS WILL INCREASE DURING THE
MORNING. WINDS AT KJMS SHOULD BECOME NORTHERLY BY AROUND DAYBREAK
AND INCREASE THROUGH THE MORNING.

&&

.HYDROLOGY...
ISSUED AT 340 PM CDT SAT MAY 16 2015

FORECAST PRECIPITATION AMOUNTS THROUGH SUNDAY NIGHT RANGE BETWEEN
ONE AND TWO INCHES. CONFIDENCE IS LOW REGARDING TIMING AND
PLACEMENT OF RAIN SHOWERS AND THUNDERSTORMS...THUS AFFECTING
EXPECTED RAINFALL AMOUNTS. FUTURE FORECASTS MAY NEED TO INCLUDE AN
AREAL FLOOD WATCH...ESPECIALLY IF FORECAST CONFIDENCE INCREASES.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE...JV
SHORT TERM...WAA
LONG TERM...AJ
AVIATION...JV
HYDROLOGY...WAA



AREA FORECAST DISCUSSION

NWS GRAND FORKS ND

 1123 PM CDT SAT MAY 16 2015

.UPDATE...
ISSUED AT 1122 PM CDT SAT MAY 16 2015

FORECAST CHALLENGE FOR REMAINDER OF THE NIGHT WILL BE TRENDS ON
DECREASING SHOWERS AND ISOLATED TSTMS AS THE FIRST WAVE OF PRECIP
IN THE WEST MOVES INTO SOUTHERN CANADA AND SHOWERS IN THE EAST
MOVE INTO NE MINNESOTA. THE HRRR HAS BEEN USEFUL FOR 3 TO 6 HOURS
OUT TONIGHT...AND WILL CONTINUE USING ITS POP TRENDS FOR GUIDANCE.
THERE IS A PRECIP FREE AREA MAINLY ACROSS WITHIN THE RED RIVER
VALLEY AND ADJACENT COUNTIES...WITH MOST PRECIP OVER DVL BASIN AND
FORESTED AREAS OF MN. WILL SEE A GRADUAL DISSIPATION OVERNIGHT
WITH ANOTHER WAVE OF PRECIP FORMING OVER CNTRL PLAINS NEAR MORNING
AND SPREADING NORTHWARD BY MID MORNING AND THROUGHOUT THE
AFTERNOON. WILL KEEP SCT SHOWERS/ISOLD TSTMS OVERNIGHT TONIGHT
ACROSS THE REGION.

&&

.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 320 PM CDT SAT MAY 16 2015

FORECAST CHALLENGE FOR TONIGHT IS SEVERE POTENTIAL. CLOUDS HAVE
PLAYED INTO THIS A BIT FOR OUR FA TODAY...PROBABLY MOST FOR THE
NORTHERN HALF OF THE AREA. AS OF 20Z THE BROAD SFC LOW WAS LOCATED
SOMEWHERE OVER WESTERN SD. THE WARM FRONT EXTENDED OUT TO THE EAST
INTO NORTHEAST SD AND SOUTHERN MN. SEEING SOUTH WINDS BEHIND THE
FRONT AND MORE SOUTHEAST THEN ESE UP INTO THE SOUTHERN FA. TEMPS
BEHIND THE FRONT IN THE MID 70S WITH DEW POINTS IN THE LOWER 60S.
THIS IS GIVING SFC BASED CAPE VALUES OF 1000 J/KG UP INTO SOUTH
CENTRAL ND. MUCH HIGHER VALUES OVER EAST CENTRAL SD. NOT THE
GREATEST AMOUNT OF SHEAR...BUT ALSO BETTER SOUTH OF THE FA.
RECEIVED A SWOMCD AT 210 PM DISCUSSING THE POTENTIAL FOR SEVERE
WEATHER UP INTO OUR FAR SOUTHERN FA. IF ORGANIZED CONVECTION CAN
GET GOING HERE THIS WOULD BE THE FAVORED AREA FOR A WATCH. THINK
THE BEST POTENTIAL WILL STILL BE IN THE 4-5 PM THROUGH MID EVENING
TIME FRAME DOWN IN THIS AREA. THUNDERSTORMS SHOULD DECREASE IN
INTENSITY OVERNIGHT...BUT AS THE STRONGER DYNAMICS APPROACH ON
SUNDAY THERE SHOULD COULD BE ANOTHER CHANCE OF SEVERE WEATHER.
THIS TIME ACROSS THE SOUTHEAST FA AS THE LOW LEVEL AND UPPER JET
PUNCH INTO THIS AREA AHEAD OF THE SHORT WAVE.

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 320 PM CDT SAT MAY 16 2015

TEMPS FALL AND WINDS CRANK UP ACROSS THE NORTHWEST FA SUNDAY
NIGHT. COULD BE A LITTLE LIGHT SNOW ACROSS THIS AREA...CURRENTLY
SHOWING THE POTENTIAL FOR 1-3 INCHES FROM LANGDON TO KDVL. STILL
WINDY INTO MONDAY WITH SOME LINGERING LIGHT SNOW ACROSS PORTIONS
OF THE NORTHERN FA. FINALLY SEE PCPN MOVING EAST MON NIGHT INTO
TUE.

BEYOND...FOR THE LATER HALF OF THE WEEK INTO THE FIRST PART OF
THE WEEKEND HIGH PRESSURE DOES SITUATE ITSELF ALONG THE NORTH
DAKOTA/MANITOBA AND SASKATCHEWAN BORDERS. THIS WILL BRING SOME
WELCOME DRY WEATHER TO OUR AREA MID TO LATE WEEK. THERE IS A
SYSTEM MOVING INTO THE WEST COAST AND INTO THE CENTRAL PLAINS FRI-
SAT AND THE NORTHERN EDGE OF MOISTURE FROM THIS SYSTEM MAY BRUSH
SOUTHERN ND AND WEST CENTRAL MINNESOTA. 00Z ECMWF WAS MORE
AGGRESSIVE WITH PRECIP THAN ITS 12Z RUN. 12Z ECMWF RUN FOLLOWS
DRIER 00Z AND 12Z GFS RUNS. BUT KEPT IDEA OF LOW POPS IN THE
SOUTHERN FCST AREA DUE TO UNCERTAINTY WITH NORTHERN EDGE OF
MOISTURE. TEMPERATURES WARMING A BIT BACK CLOSER TO NORMAL VALUES.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1122 PM CDT SAT MAY 16 2015

SHOWERS AND TSTMS WILL MOVE OUT OF DVL AND BJI AREAS BY 07Z TO
08Z TIMEFRAME AND THE ENTIRE AREA SHOULD SEE A BREAK OVERNIGHT.
THE NEXT WAVE OF MAINLY SHOWERS WITH SOME EMBEDDED TSTMS WILL
ENTER SOUTHERN VALLEY NEAR SUNRISE AND SPREAD NORTH THROUGH THE
DAY...WITH WIDESPREAD COVERAGE TOMORROW AFTN. EXPECT PREDOMINANT
CIG TO BE LOWER MVFR RANGE WITH SOME DIPS INTO IFR THROUGH THE
DAY. THE DVL SHOULD RECEIVE THE WORSE CONDS AS THE RAIN WILL BE
ACCOMPANIED BY WIND GUSTS UP TO 50 MPH BY LATE TOMORROW AFTN INTO
THE EVENING.

&&

.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&

$$

UPDATE...SPEICHER
SHORT TERM...GODON
LONG TERM...GODON/RIDDLE
AVIATION...SPEICHER




AREA FORECAST DISCUSSION

NWS CHARLESTON WV

 1159 PM EDT MON MAY 18 2015

.SYNOPSIS...
COLD FRONT CROSSES FIRST THING TUESDAY MORNING.  HIGH PRESSURE
BUILDS TOWARD THE AREA ON WEDNESDAY.  IT MAT BE TEMPORARILY THWARTED
BY A WAVE ON THURSDAY...BEFORE BUILDING IN IN ERNEST ON FRIDAY.

&&

.NEAR TERM /THROUGH TUESDAY/...
SENT A QUICK UPDATE TO ADJUST POPS PER LATEST RADAR IMAGES. A
BROKEN LINE OF SHOWERS...WITH FEW LIGHTNING STRIKES TO OUR FAR
SOUTH OVER THE WESTERN SLOPES OF WV AND EXTREME SOUTHWEST VA...MOVING
EAST AROUND 15 KNOTS. BEHIND THIS LINE RADAR LOOKS DRY EVEN ALONG
THE UPCOMING COLD FRONT. THEREFORE...KEPT HIGH CHANCE WITH THE
SHOWERS AND REMOVE CHANCES BEHIND IT. REST OF FORECAST REMAINS ON
TRACK.

PREVIOUS DISCUSSION BELOW...
815 PM UPDATE...
FINE TUNED POPS TO KEY IN MAINLY ON BROKEN LINE OF SHOWERS
CROSSING THE OHIO RIVER AS OF 00Z. THE LINE CLOSER TO THE FRONT
WILL MOSTLY FALL APART BEFORE REACHING THE FCST AREA OVERNIGHT
TONIGHT. THE THREAT FOR THUNDER OVERALL QUICKLY WANES TONIGHT. THE
COLD FRONT CROSSES/MIXES THROUGH TUE MORNING.

PREV DISCN...
SCATTERED POPCORN CONVECTION IS BEING SEEN ACROSS THE AREA THIS
AFTERNOON...AS MOIST AIR MASS HEATS UP IN BOUNDARY LAYER HEATING.
OTHERWISE...SLIGHTLY MORE ORGANIZED CONVECTION NOTED OVER EASTERN
KY AND SOUTHERN OH...AS WEAK VORT FEATURE APPROACHES FROM THE
WEST. IT APPEARS THE LATEST RAP RUNS HAVE A FAIR HANDLE ON THE
OVERALL MASS FIELDS AND THE PROGRESSION OF FEATURES ACROSS
TONIGHT. USED A RATHER BROAD BRUSH APPROACH TO COVER POPS THIS
AFTERNOON AND THIS EVENING. HAVE FRONT CROSSING LATE TONIGHT AND
EARLY MORNING. SPEED UP TIMING SLIGHTLY...BY AN HOUR OR TWO...NOT
MUCH TO REALLY MAKE A CHANGE TO THE OVERALL FORECAST.

FOR TEMPS...WILL SEE A FEW DEGREES OF COOLING TUESDAY OVER TODAYS
HIGHS AS COOLER AIR MASS MOVES IN...WITH DRYING OF THE ATMOSPHERIC
COLUMN.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
ZONAL FLOW FOR THE SHORT TERM PART OF THE FORECAST SHOULD PROVIDE
FOR A DRY FORECAST. DO HAVE SLIGHT CHANCE POPS WEDNESDAY NIGHT AS
SEVERAL UPPER LEVEL DISTURBANCES MOVE ACROSS THE NORTHERN OHIO VALLEY
AROUND THE 520+ LOW OVER NEWFOUNDLAND.

WENT MAINLY WITH ALL BLEND GUIDANCE FOR TEMPERATURES THROUGH THE
PERIOD...KEEPING THEM BELOW CLIMATOLOGY.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
A HIGH BEGINS TO BUILD IN THE GULF OF MEXICO ON SUNDAY...MIGRATES
EAST AND TRIES TO STRENGTHEN. THIS WILL LEAD TO A POTENTIALLY
MESSY FORECAST FOR THE OHIO VALLEY WITH SEVERAL UPPER LEVEL
DISTURBANCES ROTATING AROUND THE CANADIAN LOW PRESSURE SYSTEMS.
HAVE CHANCE POPS ON SUNDAY AND MONDAY AS EXPECT MOISTURE TO BECOME
TRAPPED UNDER THE HIGH. THERE REALLY ISN/T ANYTHING SIGNIFICANT TO
FOCUS ON TO TIME THESE EVENTS.

WENT WITH A BLEND OF GUIDANCE FOR TEMPERATURES. TEMPERATURES WILL
RISE THROUGH THE EXTENDED PART OF THE FORECAST.

&&

.AVIATION /04Z TUESDAY THROUGH SATURDAY/...
COLD FRONT CROSSES TUE...EARLY ENOUGH TO PRECLUDE A THUNDERSTORM
THREAT.  ONE LAST LINE OF BROKEN SHOWERS...WELL IN ADVANCE OF THE
COLD FRONT...WAS CROSSING THE OHIO RIVER NEAR 00Z...AND WILL CROSS
WV THROUGH MIDNIGHT WITH NOTHING WORSE THAN MVFR CONDITIONS LIKELY.
THERE WAS ANOTHER BROKEN LINE OF SHOWERS AND THUNDERSTORMS NEAR THE
INDIANA / OHIO LINE...CLOSER TO THE COLD FRONT...BUT THIS LINE WILL
LIKELY FALL APART BEFORE REACHING THE MIDDLE OHIO VALLEY OVERNIGHT.

VALLEY FOG WILL AGAIN FORM OVERNIGHT E OF THE OHIO RIVER.  MVFR
STRATUS WILL ALSO FORM OVERNIGHT.  THE MORNING STRATUS WILL THEN MIX
HIGHER BEFORE MIXING OUT ALTOGETHER ON TUE.

LIGHT S TO SW FLOW OVERNIGHT WILL BECOME LIGHT W TO NW ON TUE.  IT
MAY STRENGTHEN AND BECOME JUST A BIT GUSTY TUE AFTERNOON.  LIGHT W
FLOW ALOFT OVERNIGHT WILL BECOME LIGHT TO MODERATE W TO NW ON TUE.

FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z WEDNESDAY...

FORECAST CONFIDENCE: MEDIUM.

ALTERNATE SCENARIOS: FOG AND STRATUS FORMATION OVERNIGHT AND BREAK
UP TUE MORNING MAY VARY.  THERE MAY BE MORE IFR THAN FCST ON
EITHER...ESPECIALLY E OF THE OHIO RIVER.

EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH:   TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW:    TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.

DATE                                                  TUE 05/19/15
UTC 1HRLY       02   03   04   05   06   07   08   09   10   11   12   13
EDT 1HRLY       22   23   00   01   02   03   04   05   06   07   08   09
CRW CONSISTENCY  H    M    M    M    M    M    M    H    H    H    H    M
HTS CONSISTENCY  H    H    H    M    M    M    M    M    M    M    H    H
BKW CONSISTENCY  H    H    H    H    H    H    L    L    L    L    L    L
EKN CONSISTENCY  H    M    H    L    M    M    M    L    M    L    L    L
PKB CONSISTENCY  M    H    H    H    H    H    M    M    M    M    M    M
CKB CONSISTENCY  H    H    M    H    M    M    M    L    L    L    L    M

AFTER 06Z WEDNESDAY...
FOG/LOW CLOUDS POSSIBLE OVERNIGHT TUE NT INTO WED MORNING AND
POSSIBLY AGAIN OVERNIGHT THU NT INTO FRI MORNING.

&&

.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.

&&

$$
SYNOPSIS...FB/KMC/TRM
NEAR TERM...ARJ/TRM
SHORT TERM...FB
LONG TERM...FB
AVIATION...TRM








AREA FORECAST DISCUSSION

NWS CHARLESTON WV

 817 PM EDT MON MAY 18 2015

.SYNOPSIS...
COLD FRONT CROSSES FIRST THING TUESDAY MORNING.  HIGH PRESSURE
BUILDS TOWARD THE AREA ON WEDNESDAY.  IT MAT BE TEMPORARILY THWARTED
BY A WAVE ON THURSDAY...BEFORE BUILDING IN IN ERNEST ON FRIDAY.

&&

.NEAR TERM /THROUGH TUESDAY/...
815 PM UPDATE...
FINE TUNED POPS TO KEY IN MAINLY ON BROKEN LINE OF SHOWERS CROSSING
THE OHIO RIVER AS OF 00Z.  THE LINE CLOSER TO THE FRONT WILL MOSTLY
FALL APART BEFORE REACHING THE FCST AREA OVERNIGHT TONIGHT.  THE
THREAT FOR THUNDER OVERALL QUICKLY WANES TONIGHT.  THE COLD FRONT
CROSSES/MIXES THROUGH TUE MORNING.

PREV DISCN...
SCATTERED POPCORN CONVECTION IS BEING SEEN ACROSS THE AREA THIS
AFTERNOON...AS MOIST AIRMASS HEATS UP IN BOUNDARY LAYER HEATING.
OTHERWISE...SLIGHTLY MORE ORGANIZED CONVECTION NOTED OVER EASTERN
KY AND SOUTHERN OH...AS WEAK VORT FEATURE APPROACHES FROM THE
WEST. IT APPEARS THE LATEST RAP RUNS HAVE A FAIR HANDLE ON THE
OVERALL MASS FIELDS AND THE PROGRESSION OF FEATURES ACROSS
TONIGHT. USED A RATHER BROAD BRUSH APPROACH TO COVER POPS THIS
AFTERNOON AND THIS EVENING. HAVE FRONT CROSSING LATE TONIGHT AND
EARLY MORNING. SPEED UP TIMING SLIGHTLY...BY AN HOUR OR TWO...NOT
MUCH TO REALLY MAKE A CHANGE TO THE OVERALL FORECAST.

FOR TEMPS...WILL SEE A FEW DEGREES OF COOLING TUESDAY OVER TODAYS
HIGHS AS COOLER AIRMASS MOVES IN...WITH DRYING OF THE ATMOSPHERIC
COLUMN.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
ZONAL FLOW FOR THE SHORT TERM PART OF THE FORECAST SHOULD PROVIDE
FOR A DRY FORECAST. DO HAVE SLIGHT CHANCE POPS WEDNESDAY NIGHT AS
SEVERAL UPPER LEVEL DISTURBANCES MOVE ACROSS THE NORTHERN OHIO VALLEY
AROUND THE 520+ LOW OVER NEWFOUNDLAND.

WENT MAINLY WITH ALL BLEND GUIDANCE FOR TEMPERATURES THROUGH THE
PERIOD...KEEPING THEM BELOW CLIMATOLOGY.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
A HIGH BEGINS TO BUILD IN THE GULF OF MEXICO ON SUNDAY...MIGRATES
EAST AND TRIES TO STRENGTHEN. THIS WILL LEAD TO A POTENTIALLY
MESSY FORECAST FOR THE OHIO VALLEY WITH SEVERAL UPPER LEVEL
DISTURBANCES ROTATING AROUND THE CANADIAN LOW PRESSURE SYSTEMS.
HAVE CHANCE POPS ON SUNDAY AND MONDAY AS EXPECT MOISTURE TO BECOME
TRAPPED UNDER THE HIGH. THERE REALLY ISN/T ANYTHING SIGNIFICANT TO
FOCUS ON TO TIME THESE EVENTS.

WENT WITH A BLEND OF GUIDANCE FOR TEMPERATURES. TEMPERATURES WILL
RISE THROUGH THE EXTENDED PART OF THE FORECAST.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
COLD FRONT CROSSES TUE...EARLY ENOUGH TO PRECLUDE A THUNDERSTORM
THREAT.  ONE LAST LINE OF BROKEN SHOWERS...WELL IN ADVANCE OF THE
COLD FRONT...WAS CROSSING THE OHIO RIVER NEAR 00Z...AND WILL CROSS
WV THROUGH MIDNIGHT WITH NOTHING WORSE THAN MVFR CONDITIONS LIKELY.
THERE WAS ANOTHER BROKEN LINE OF SHOWERS AND THUNDERSTORMS NEAR THE
INDIANA / OHIO LINE...CLOSER TO THE COLD FRONT...BUT THIS LINE WILL
LIKELY FALL APART BEFORE REACHING THE MIDDLE OHIO VALLEY OVERNIGHT.

VALLEY FOG WILL AGAIN FORM OVERNIGHT E OF THE OHIO RIVER.  MVFR
STRATUS WILL ALSO FORM OVERNIGHT.  THE MORNING STRATUS WILL THEN MIX
HIGHER BEFORE MIXING OUT ALTOGETHER ON TUE.

LIGHT S TO SW FLOW OVERNIGHT WILL BECOME LIGHT W TO NW ON TUE.  IT
MAY STRENGTHEN AND BECOME JUST A BIT GUSTY TUE AFTERNOON.  LIGHT W
FLOW ALOFT OVERNIGHT WILL BECOME LIGHT TO MODERATE W TO NW ON TUE.

FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z WEDNESDAY...

FORECAST CONFIDENCE: MEDIUM.

ALTERNATE SCENARIOS: FOG AND STRATUS FORMATION OVERNIGHT AND BREAK
UP TUE MORNING MAY VARY.  THERE MAY BE MORE IFR THAN FCST ON
EITHER...ESPECIALLY E OF THE OHIO RIVER.

EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH:   TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW:    TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.

DATE                                                            TUE 05/19/15
UTC 1HRLY       00   01   02   03   04   05   06   07   08   09   10   11
EDT 1HRLY       20   21   22   23   00   01   02   03   04   05   06   07
CRW CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
HTS CONSISTENCY  H    H    H    H    H    H    H    H    H    M    M    H
BKW CONSISTENCY  H    M    M    M    M    H    H    H    L    L    L    L
EKN CONSISTENCY  M    M    M    M    H    L    L    L    L    M    M    M
PKB CONSISTENCY  H    H    H    H    H    H    H    H    H    M    M    M
CKB CONSISTENCY  M    M    M    M    H    H    L    L    L    L    L    L

AFTER 00Z WEDNESDAY...
FOG/LOW CLOUDS POSSIBLE OVERNIGHT TUE NT INTO WED MORNING AND
POSSIBLY AGAIN OVERNIGHT THU NT INTO FRI MORNING.

&&

.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.

&&

$$
SYNOPSIS...FB/KMC/TRM
NEAR TERM...KMC/TRM
SHORT TERM...FB
LONG TERM...FB
AVIATION...TRM







AREA FORECAST DISCUSSION

NWS CLEVELAND OH

 131 PM EDT SUN MAY 17 2015

.SYNOPSIS...
A WARM FRONT NORTH OF LAKE ERIE WILL LIFT SLOWLY NORTH TODAY AND
TONIGHT. A COLD FRONT WILL PASS THROUGH THE AREA LATE MONDAY
NIGHT. HIGH PRESSURE WILL BUILD IN TOWARD MID WEEK.


.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LOWERED TEMPS A FEW DEGREES IN THE WEST. LOWERED POPS IN THE EAST
THIS AFTERNOON TO CHANCE POPS. BOTH THE NAM AND THE HRRR SHOWS THIS
WAVE OF SHOWERS MOVING EAST THIS MORNING WITH MORE CONVECTION
DEVELOPING FROM THE WEST.

ORIGINAL DISCUSSION...WARM FRONT JUST TO OUR NORTH WITH SOUTHERLY
FLOW CONTINUING TO BRING MOIST AIR INTO THE AREA OUT OF THE GULF
REGION. SHOWERS ALREADY MOVING THROUGH SOUTHERN AND SOUTHEASTERN
COUNTIES...HELPED BY WEAK SHORT WAVE MOVING THROUGH THE REGION.
EXPECT THIS ACTIVITY TO DRIFT EAST OUT OF THE AREA THROUGH THE
MORNING WITH ADDITIONAL SHOWERS ALONG WITH A FEW THUNDERSTORMS
REDEVELOPING WITH HEATING THIS AFTERNOON. WILL HAVE HIGHEST POPS
SOUTHEAST IN THE LIKELY CATEGORY AND HIGH CHANCE POPS ELSEWHERE.
HIGHS 70S AND LOWER 80S.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
LATE TONIGHT INTO MONDAY THE UPPER RIDGE OVER THE AREA BEGINS TO
SHIFT EAST AND ANOTHER SHORTWAVE IMPULSE BEGINS TO RIDE UP RIDGE
TOWARD THE AREA. HOWEVER...AT THIS POINT IT APPEARS THE BETTER
DYNAMICS WILL STAY SOUTH OF THE AREA. MONDAY AFTERNOON
THUNDERSTORMS WILL INCREASE AHEAD OF A COLD FRONT. RIGHT NOW IT
LOOKS LIKE THE FRONT WON`T ACTUALLY CLEAR CLEVELAND UNTIL
3AM...HOWEVER...THE GREATEST THREAT FOR THUNDERSTORMS WILL OCCUR
OUT AHEAD OF THE FRONT WITH BETTER SURFACE BASED INSTABILITY. THE
UPPER LEVEL PATTERN BECOMES RELATIVELY ZONAL FOR THE REST OF
TUESDAY AND INTO WEDNESDAY AS THINGS DRY OUT AT THE SURFACE AND
HIGH PRESSURE BEGINS TO SETTLE IN.

&&

.LONG TERM /THURSDAY THROUGH SATURDAY/...
MODELS REMAIN IN GOOD AGREEMENT DROPPING LARGE AREA OF CANADIAN HIGH
PRESSURE OVER THE REGION THURSDAY THROUGH EARLY SATURDAY.  THE HIGH
WILL MOVE EAST OFF THE MID ATLANTIC COAST LATE SATURDAY INTO SUNDAY.
EXPECTING DRY CONDITIONS ACROSS THE REGION WITH THE HIGH MOVING
ACROSS. SATURDAY NIGHT AND SUNDAY BROUGHT IN CHANCE POPS AS MOISTURE
RETURN IN SOUTHERLY RETURN FLOW ON THE WEST SIDE OF THE HIGH. TEMPS
GENERALLY ON THE COOL SIDE BUT MODERATING THROUGH THE PERIOD.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
OCCASIONAL SHOWERS...SOME THUNDER...AND VARIABLE SKY CONDITIONS
WILL CONTINUE INTO MONDAY ACROSS ALL TAF SITES. AN EXITING ROUND
OF SHOWERS WILL MOVE ACROSS NW PA AND KERI EARLY THIS AFTERNOON. A
NEW ROUND OF SHOWERS...SOME OF WHICH COULD DEVELOP FURTHER INTO
TS...NOW POPPING UP FROM KFDY TO KCMH. THIS AREA WILL DRIFT EAST-
NORTHEAST THROUGH THE REMAINDER OF THE AFTERNOON...PEAKING WITH
THE MAX DAYTIME HEATING. MULTI-LEVEL CLOUD DECKS WILL CONTINUE AND
WILL LARGELY BE MVFR TO LOW END VFR. TEMPORARY IFR CONDITIONS
WITHIN ANY SHOWER. WITH THE SUPER MOIST ATMOSPHERE STICKING
AROUND...COULD SEE A SHOWER AT JUST ABOUT ANYTIME TONIGHT. ALSO
WILL LIKELY SEE CONDITIONS DIP BACK DOWN INTO MVFR RANGE WITH VSBY
AND/OR CEILINGS. UNSURE ABOUT THE LIKELIHOOD OF IFR OVERNIGHT. IT
WILL BUBBLE BACK UP AGAIN TOMORROW WITH THE COLD FRONT EXPECTED TO
MOVE ACROSS MONDAY EVENING. THUNDERSTORMS EXPECTED TO BE MORE
ORGANIZED MONDAY...AND SOME COULD BE STRONG. LIGHT SOUTHERLY TO
SSW FLOW WILL CONTINUE OVER THE NEXT 24 HRS. LAKE BREEZE FOR KERI
TODAY REVERSES THIS EVENING. THIS LAKE BREEZE SHOULD NOT REACH
KCLE TODAY.

.OUTLOOK...NON VFR AT TIMES IN SCATTERED SHOWERS OR THUNDERSTORMS
THROUGH MON NIGHT.

&&

.MARINE...
LIGHT SOUTH TO SOUTHWEST FLOW WILL CONTINUE TODAY THROUGH MONDAY
NIGHT.  SMALL CRAFT ADVISORY LIKELY NEEDED TUESDAY INTO WEDNESDAY AS
WEST TO SOUTHWEST WINDS INCREASE TO 15 TO 20 KNOTS. A SECOND
REINFORCING SHOT OF COLD AIR WILL COME WITH A SECONDARY COLD FRONT
WILL COME THROUGH LATE TUESDAY...TURNING WINDS MORE NORTHWEST AT
AROUND 20 KNOTS.  WEDNESDAY NIGHT WINDS WILL SUBSIDE AS HIGH
PRESSURE BUILDS IN FROM THE WEST.

&&

.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...MAYERS
NEAR TERM...DJB/MAYERS
SHORT TERM...MAYERS
LONG TERM...TK
AVIATION...OUDEMAN
MARINE...TK






AREA FORECAST DISCUSSION

NWS TULSA OK

 359 PM CDT SUN MAY 17 2015

.DISCUSSION...
NEXT COUPLE OF DAYS MARGINAL CHANCE FOR SHOWERS
THUNDERSTORMS MAINLY SOUTH WHERE BETTER MOISTURE
RESIDES.  WRF MODEL AN OUTLIER REGARDING PRECIP
AND POP SOUTHEAST AND NORTHWEST ARKANSAS. DRIER
SHORT TERM HRRR LOOKS GOOD TONIGHT.

NEXT BIG RAIN TUESDAY NIGHT  WEDNESDAY WHEN THE
NEXT SHOT OF ENERGY EJECTED FROM THE SOUTHWEST.
CHANCE POPS THURSDAY INTO FRIDAY.

UPPER LOW OVER THE SOUTHWEST FRIDAY MOVES ACROSS
THE ROCKIES AND INTO THE CENTRAL PLAINS...SUNDAY.
ANOTHER SLUG WET WEATHER FOR THE HOLIDAY WEEKEND.
GW

&&

.PRELIMINARY POINT TEMPS/POPS...
TUL   64  83  60  75 /  10  10  10  10
FSM   68  84  66  81 /  30  30  20  20
MLC   67  84  63  80 /  10  20  20  30
BVO   58  81  54  72 /  10  10  10  10
FYV   62  81  58  76 /  30  30  20  10
BYV   64  81  57  75 /  30  30  20  10
MKO   64  83  61  77 /  10  10  10  30
MIO   63  80  56  73 /  10  10  10  10
F10   64  83  61  77 /  10  10  10  30
HHW   68  83  67  81 /  40  30  20  40

&&

.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&

$$

SHORT TERM...14
LONG TERM....21






AREA FORECAST DISCUSSION

NWS MEDFORD OR

 521 PM PDT MON MAY 18 2015

.SHORT TERM...MOISTURE CONTINUES TO ROTATE IN OVER OUR AREA FROM
THE EAST AS AN UPPER LOW MOVES INTO THE GREAT BASIN. DYNAMICS ARE
WEAK, BUT THERE IS PLENTY OF INSTABILITY PRESENT FROM THE CASCADE
CREST AND SISKIYOUS EASTWARD, AND NUMEROUS SHOWERS AND ISOLATED
THUNDERSTORMS HAVE ALREADY DEVELOPED. THIS CONVECTION WILL
INCREASE IN COVERAGE AND MIGRATE TOWARD THE WEST THROUGH THE
AFTERNOON. CONVECTION IS ALREADY TRYING TO SPILL OVER ONTO THE
WEST SIDE, BUT IT IS BEING INHIBITED BY THE LITTLE REMAINING CAP.
THE SUN IS PEAKING THROUGH IN THE WEST SIDE VALLEYS AND THE
SURFACE HEATING WILL BREAK THE CAP PRETTY SOON. MESOANALYSIS
INDICATES WE`VE BUILT 500-1000 J/KG OF SURFACE BASED CAPE
OVER JACKSON AND JOSEPHINE COUNTIES ALREADY, WHICH SHOULD BE
RELEASED EVENTUALLY, AND RESULT IN SHOWERS AND THUNDERSTORMS THERE
AS WELL. LATEST RAP AND HRRR GUIDANCE ACTUALLY SHOWS QUITE A LOT
OF CONVECTION OVER THE ROGUE AND ILLINOIS VALLEYS LATER THIS
AFTERNOON. THEY MAY BE A BIT OVERDONE, BUT PEOPLE IN THESE AREAS
SHOULD KEEP AN EYE ON THE SKY. AS OPPOSED TO YESTERDAY, THE SUN IS
ALSO POKING OUT IN THE UMPQUA, AND THEY DO STAND A BETTER CHANCE
OF SEEING SOME THUNDERSTORMS THIS AFTERNOON AS WELL. THERE IS A
LOT OF MOISTURE IN THE PROFILE (PRECIPITABLE WATER IS NEAR AN
INCH) AND THUS ANY OF THESE STORMS WILL BE CAPABLE OF PRODUCING
SMALL HAIL AND HEAVY DOWNPOURS. WITH LITTLE WIND ALOFT TO SPEAK
OF, STRONG WINDS SHOULDN`T BE MUCH OF A CONCERN, BUT WE COULD SEE
GUSTY WINDS AROUND STORMS.

THINGS WILL STABILIZE TONIGHT AS THE BOUNDARY LAYER COOLS, BUT
SHOWERS ARE LIKELY TO CONTINUE OVERNIGHT ALONG THE MOUNTAINS AND
EAST SIDE. AS BROAD TROUGHING REMAINS OVER THE REGION, WE EXPECT
TO REPEAT THIS BASIC DIURNAL PATTERN OF NIGHT TIME SHOWERS AND
MORE WIDESPREAD SHOWERS AND THUNDERSTORMS IN THE AFTERNOONS
TOMORROW THROUGH THURSDAY. WE SHOULD GRADUALLY BECOME MORE STABLE
ON THE WEST SIDE, SO THUNDERSTORMS BECOME LESS OF AN ISSUE. ONE
BIGGER CHANGE I MADE WAS TO INCREASE POPS OVER THE WEST SIDE
TUESDAY NIGHT INTO WEDNESDAY MORNING AS ALL THE MODELS ARE SHOWING
A DEFORMATION BAND FORMING OVER THE AREA. -WRIGHT

.LONG TERM...THE MODELS SHOW THE WEAK UPPER LOW MOVING INTO
ARIZONA WITH WEAK RIDGING BUILDING OFFSHORE. THE GFS SHOWS MORE
RIDGING COMPARED TO THE EC AND BOTH CONTINUE TO SHOW QPF OVER MOST
OF THE AREA. I SUSPECT THE QPF MAY BE OVERDONE NOT ONLY WITH
AMOUNTS, BUT ALSO THE COVERAGE. THUS HAVE SCALED BACK ON POPS FOR
FRIDAY. ANOTHER WEAK UPPER LOW MOVES INTO THE AREA SATURDAY, BUT
THIS ONE WILL BE COMING IN FROM THE NORTHWEST AND IS NOT EXPECTED
TO HAVE ANY OVER WATER TRAJECTORY, THEREFORE MOISTURE WILL BE
LIMITED AND ANY SHOWERS SHOULD BE ISOLATED AND EAST OF THE
CASCADES. THE EC AND GFS DISAGREE WITH THE PROGRESSION OF THE
UPPER LOW SUNDAY AND THE UPSTREAM UPPER LOW. THE GFS KEEPS THE
UPPER LOW OVER THE AREA SUNDAY WHILE THE EC MOVES IT INTO NORTHERN
CAL. FOR NOW WE`LL GO WITH A BLEND BETWEEN THE TWO AND KEEP A
SLIGHT CHANCE OF SHOWERS EAST OF THE CASCADES. THE ENSEMBLE MEAN
SHOWS A LARGE SPREAD IN THIS TIME PERIOD WHICH YIELDS LOWER
CONFIDENCE IN THE FORECAST. -PETRUCELLI

&&

.AVIATION...FOR THE 19/00Z TAF CYCLE...CURRENT RADAR IMAGERY SHOWS
MORE SHOWERS THAN THUNDERSTORMS ACROSS THE CWA.  LOOK FOR THE
POTENTIAL FOR THUNDERSTORMS TO DIMINISH THIS EVENING. RIGHT NOW VFR
CIGS ARE STILL PREVAILING, YET MVFR CIGS SHOULD DEVELOP LATER
TONIGHT INTO TUESDAY MORNING UNDER A STABLE AIR MASS WITH PLENTY OF
LOW LEVEL MOISTURE.  VFR AND BKN TO OVC DECKS WILL CONTINUE TOMORROW
WITH PLENTY OF MISTURE MOISTURE AND VERTICAL MOTION. /CS

&&

.MARINE...UPDATED 200 PM PDT, MONDAY 18 MAY 2015...A PATTERN OF
WEAK HIGH PRESSURE OFFSHORE AND WEAK LOW PRESSURE INLAND WILL
PERSIST MOST OF THIS WEEK WITH LIGHT TO MODERATE NORTH WINDS AND
NORTHWEST SWELL OVER THE WATERS. WINDS WILL APPROACH SMALL CRAFT
ADVISORY LEVELS ON TUESDAY EVENING AND WEDNESDAY MORNING SOUTH OF
CAPE BLANCO. AFTER THIS NORTH WINDS AROUND 10-20 KTS WILL CONTINUE
INTO THE WEEKEND. /CS

&&

.FIRE WEATHER...UPDATED 200 PM PDT, MONDAY 18 MAY 2015...AN UPPER
LOW CENTERED JUST EAST OF THE BAY AREA IS SENDING MOISTURE NORTHEAST
TOWARDS THE AREA. SO FAR ISOLATED STORMS HAVE BEEN CONFINED TO THE
CASCADES EAST, BUT THEY ARE EXPECTED TO BECOME MORE FREQUENT AS THE
AFTERNOON PROGRESSES INTO THIS EVENING. THE LATEST MESOSCALE  ANALYSIS
SHOWS HIGHER CAPE VALUES WEST OF THE CASCADES COMPARED TO YESTERDAY
AND THE MOIST LAYER IS MUCH DEEPER ALL THE WAY UP TO 400 MB BASED IN
THIS MORNINGS SOUNDING. THE 700 MB FLOW WILL BE FROM THE EAST TO
NORTHEAST, THERE IS A BETTER CHANCE FOR SHOWERS AND ISOLATED STORMS
TO MAKE THEIR WAY WEST OF THE CASCADES. WITH PLENTY OF MOISTURE
AVAILABLE, THUNDERSTORMS ARE LIKELY TO BE RAIN PRODUCERS AND THEY
WILL BE SLOW MOVERS. SO HEAVY RAINFALL IS POSSIBLE.

THUNDERSTORMS WILL DECREASE THIS EVENING AND END TONIGHT, BUT WE`LL
CONTINUE TO GET MUCH NEEDED RAIN SHOWERS OVERNIGHT TONIGHT.

THE UPPER LOW WILL MOVE EAST AND WEAKEN TUESDAY WITH THE BEST CHANCE
FOR THUNDERSTORMS ALONG AND EAST OF THE CASCADES. THE ATMOSPHERE IS
EXPECTED TO BE MORE STABLE WEST OF THE CASCADES DUE TO A MARINE
INFLUENCE, SO WERE ONLY EXPECTING SHOWERS. -PETRUCELLI

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.

CA...NONE.

PACIFIC COASTAL WATERS...NONE.

$$



AREA FORECAST DISCUSSION

NWS STATE COLLEGE PA

 1155 PM EDT MON MAY 18 2015

.SYNOPSIS...
A NEARLY STATIONARY...BACK DOOR COLD FRONT WILL BE LOCATED ACROSS
THE SUSQUEHANNA VALLEY TONIGHT. THIS BOUNDARY WILL COMBINE WITH AN
EXTENSIVE PLUME OF DEEP MOISTURE TO FOCUS ADDITIONAL HEAVY
SHOWERS AND THUNDERSTORMS ACROSS CENTRAL PENNSYLVANIA AND THE
SUSQUEHANNA VALLEY OVERNIGHT. A SEPARATE COLD FRONT WILL APPROACH
FROM THE UPPER MIDWEST...PUSHING SOUTHEAST ACROSS THE COMMONWEALTH
TUESDAY AND BRINGING WITH IT...ANOTHER FEW ROUNDS OF SHOWERS AND
THUNDERSTORMS TUESDAY. A COOLER AND DRY AIRMASS WILL MOVE IN
BEHIND THE COLD FRONT FOR THE MIDDLE OF THIS WEEK. SATURDAY AND
SUNDAY SHOULD FEATURE DRY WEATHER WITH PLEASANTLY LOW HUMIDITY
AND NEAR TO SLIGHTLY BELOW NORMAL HIGH TEMPERATURES. WARMER
TEMPERATURES AND MUGGINESS WILL RETURN FOR MEMORIAL DAY.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
VERY HIGH PWAT AIR WILL STAY PARKED OVER THE AREA THROUGH THE
OVERNIGHT. HOWEVER...WITH THE LOSS OF DAYTIME HEATING...
INSTABILITY AND PRECIP RATES IN THE SHRA/TSRA HAVE STEADILY
DIMINISHED.

NEARLY STATIONARY/BACK DOOR CFRONT JUST WEST OF THE SUSQ RIVER
MAINSTEM WILL HELP TO REFIRE AND FOCUS ADDITIONAL LOW-TOPPED
CONVECTION THROUGH THE OVERNIGHT HOURS WITH BASIN AVG RAINFALL
AMOUNTS GENERALLY AROUND ONE QUARTER OF AN INCH. THE FEW LOCATIONS
THAT SEE SLOW MVG OR TRAINING HEAVY SHRA/TSRA WILL PICK UP ANOTHER
0.5 TO 1.0 OF RAIN...PERHAPS LEADING TO SOME ADDITIONAL MINOR
FLOODING NEAR AND TO THE EAST OF A KSEG TO KMDT AND KTHV LINE.

ELSEWHERE...A RATHER MILD/MUGGY NIGHT IS IN STORE WITH ISOLATED TO
SCTD SHRA. LOWS EARLY TUESDAY WILL BE IN THE 60-65F RANGE FROM
NORTH TO SOUTH.

FOG AND LOW CLOUDS ARE AGAIN EXPECTED OVER MOST/ALL OF THE AREA
LATE TONIGHT/EARLY TUESDAY. PERHAPS ONLY THE PLACES WHICH CAN
KEEP WIND OVER 5-6KTS THROUGH THE NIGHT - MAINLY HIGHER ELEVS IN
THE WEST - CAN STAY AWAY FROM BAD VISBYS.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
COLD FRONT PUSHES SE ACROSS THE REGION TUESDAY. DEWPOINTS DROP
THROUGH THE DAY IN THE NW HALF OF THE CWA...BUT THE SE WILL STAY
VERY WARM AND HUMID THROUGH MOST OF THE AFTERNOON. PWATS STILL AOA
35 MM NEAR AND SE OF THE I-81 CORRIDOR THROUGH 18Z TUESDAY...AND
THE COMBINATION OF THE HEAT AND MOISTURE WILL HELP TO FIRE UP SFC-
BASED CAPES INTO THE 1500-2000 J/KG RANGE. EXPECT A BKN LINE OR
TWO OF SHOWERS AND PERHAPS A RUMBLE OF THUNDER ALONG THE CFRONT
FROM NEAR KELM...TO KUNV AND KJST DURING THE MIDDAY HOURS. THIS
AREA OF CONVECTION WILL LIKELY INTENSIFY INTO A BKN LINE OF STRONG
TSRA AFTER 16Z TUESDAY NEAR A KAVP TO KSEG AND KHGR LINE.

SPC/S MARGINAL RISK FOR SVR TSRA NIPS A FEW OF OUR EASTERN
COUNTIES TUESDAY...AND COULD SEE THIS BEING EXTENDED A TAD FURTHER
TO THE SW BASED MAINLY ON INSTABILITY AND A LOCALIZED LARGE HAIL
THREAT /COMPARED TO BETTER DEEP LAYER SHEAR FURTHER NORTH/.

&&

.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
AREA OF SHOWERS/TSTMS WILL BE DEPARTING LATE TUE/EARLY TUE
EVE...ASSOCIATED WITH A COLD FRONT CLEARING THE REGION.

IN IT/S WAKE...RESPECTABLE ANTICYCLONE WILL BUILD IN FROM THE WEST
WITH A PUSH OF NOTICEABLY COOLER AND DRIER AIR FILTERING IN FOR
MIDWEEK. A WEAK WAVE EJECTS EASTWARD FROM THE S PLAINS TOWARD THE
CAROLINA/S ON THU...WHILE TROUGH CONTINUES TO SPIN OVER EASTERN
CANADA. CENTRAL PA REMAINS BETWEEN THESE TWO FEATURES...WHICH WILL
KEEP US DRY. EVEN WITH NW FLOW...DAYTIME TEMPS WILL REBOUND A BIT
WARMER EACH DAY. BUT DIURNAL TEMP RANGES WILL BE FAIRLY LARGE
THANKS TO THE DRIER AIRMASS...WHICH WILL BRING CHILLY MORNINGS.
THE COLDEST CONTINUES TO LOOK LIKE THURSDAY MORNING WHERE THERE
REMAINS A RISK FOR PATCHY FROST...MAINLY OVER THE NORTH-CENTRAL
ZONES WHERE GUIDANCE IS SHOWING POSS FOR MID 30S AOA BFD /JUST IN
TIME FOR THE START OF THE GROWING SEASON/.

THE WEAK LOW OVER CAROLINAS/MID ATLANTIC REGION SLIDES OFFSHORE
FRI...WITH SPRAWLING HIGH PRESSURE AREA BUILDING IN FOR SAT/SUN.
ONCE RIDGE AXIS SLIDES BY SAT NIGHT...HUMIDITY WILL BEGIN TO
SLOWLY INCREASE ON SUNDAY WITH RISING TEMPS /AND ISOLATED
LATE DAY CONVECTION POSS/. WARMER AND MUGGIER CONDITIONS ON
MEMORIAL DAY...WITH SCATTERED TO EVEN NUMEROUS SHOWERS/TSTMS IN
THE FORECAST.

&&

.AVIATION /04Z TUESDAY THROUGH SATURDAY/...
SCT SHRA AND A FEW TSRA WILL CONTINUE TO FORM ACROSS CENTRAL PA
LATE THIS EVENING IN UNSTABLE AIR MASS AHEAD OF APPROACHING COLD
FRONT OVR THE MIDWEST. ANY OF THESE SHRA/TSRA COULD PRODUCE BRIEF
VIS REDUCTIONS. HOWEVER...THE MAIN AVIATION CONCERN LATE THIS
EVENING WILL BE THE DEVELOPING LOW CIGS ACROSS EASTERN PA...THE
RESULT OF MARINE AIR FLOWING OFF THE ATLANTIC OCEAN. IFR CIGS
ALREADY NOTED ACROSS MUCH OF EASTER PA AT 03Z AND NEAR TERM MDL
DATA SUPPORT THESE LOW CIGS MOVING INTO KLNS BTWN 03Z-05Z AND
POSSIBLY REACHING AS FAR WEST AS KMDT/KIPT ARND 06Z. FURTHER
WEST...A PLUME OF MOISTURE AHEAD OF APPROACHING COLD FRONT WILL
ASCEND THE W MTNS...LIKELY RESULTING IN IFR CIGS AT KBFD/KJST LATE
TONIGHT. BOTH THE SREF AND LATEST HRRR SUPPORT THIS SCENARIO.
MOST FAVORABLE CONDS OVERNIGHT SHOULD BE AT KAOO/KUNV...WHERE SIG
REDUCTIONS APPEAR UNLIKELY.

LOW CIGS ACROSS THE W MTNS AND EASTERN PA SHOULD LIFT BY LATE AM.
CAN/T RULE OUT AN ISOLD SHRA/TSRA ACROSS EASTERN PA ARND MIDDAY
WITH PASSAGE OF COLD FRONT. OTHERWISE...EXPECT A RETURN TO
WIDESPREAD VFR CONDS...AS A GUSTY WEST WIND BRINGS MUCH DRIER AIR
INTO THE REGION BEHIND THE COLD FRONT.

OUTLOOK...

WED-SAT...NO SIG WX EXPECTED.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...LAMBERT
LONG TERM...RXR
AVIATION...FITZGERALD



AREA FORECAST DISCUSSION

NWS STATE COLLEGE PA

 1056 PM EDT MON MAY 18 2015

.SYNOPSIS...
A NEARLY STATIONARY...BACK DOOR COLD FRONT WILL BE LOCATED ACROSS
THE SUSQUEHANNA VALLEY TONIGHT. THIS BOUNDARY WILL COMBINE WITH AN
EXTENSIVE PLUME OF DEEP MOISTURE TO FOCUS ADDITIONAL HEAVY
SHOWERS AND THUNDERSTORMS ACROSS CENTRAL PENNSYLVANIA AND THE
SUSQUEHANNA VALLEY OVERNIGHT. A SEPARATE COLD FRONT WILL APPROACH
FROM THE UPPER MIDWEST...PUSHING SOUTHEAST ACROSS THE COMMONWEALTH
TUESDAY AND BRINGING WITH IT...ANOTHER FEW ROUNDS OF SHOWERS AND
THUNDERSTORMS TUESDAY. A COOLER AND DRY AIRMASS WILL MOVE IN
BEHIND THE COLD FRONT FOR THE MIDDLE OF THIS WEEK. SATURDAY AND
SUNDAY SHOULD FEATURE DRY WEATHER WITH PLEASANTLY LOW HUMIDITY
AND NEAR TO SLIGHTLY BELOW NORMAL HIGH TEMPERATURES. WARMER
TEMPERATURES AND MUGGINESS WILL RETURN FOR MEMORIAL DAY.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
VERY HIGH PWAT AIR WILL STAY PARKED OVER THE AREA THROUGH THE
OVERNIGHT. HOWEVER...WITH THE LOSS OF DAYTIME HEATING...
INSTABILITY AND PRECIP RATES IN THE SHRA/TSRA HAVE STEADILY
DIMINISHED.

NEARLY STATIONARY/BACK DOOR CFRONT JUST WEST OF THE SUSQ RIVER
MAINSTEM WILL HELP TO REFIRE AND FOCUS ADDITIONAL LOW-TOPPED
CONVECTION THROUGH THE OVERNIGHT HOURS WITH BASIN AVG RAINFALL
AMOUNTS GENERALLY AROUND ONE QUARTER OF AN INCH. THE FEW LOCATIONS
THAT SEE SLOW MVG OR TRAINING HEAVY SHRA/TSRA WILL PICK UP ANOTHER
0.5 TO 1.0 OF RAIN...PERHAPS LEADING TO SOME ADDITIONAL MINOR
FLOODING NEAR AND TO THE EAST OF A KSEG TO KMDT AND KTHV LINE.

ELSEWHERE...A RATHER MILD/MUGGY NIGHT IS IN STORE WITH ISOLATED TO
SCTD SHRA. LOWS EARLY TUESDAY WILL BE IN THE 60-65F RANGE FROM
NORTH TO SOUTH.

FOG AND LOW CLOUDS ARE AGAIN EXPECTED OVER MOST/ALL OF THE AREA
LATE TONIGHT/EARLY TUESDAY. PERHAPS ONLY THE PLACES WHICH CAN
KEEP WIND OVER 5-6KTS THROUGH THE NIGHT - MAINLY HIGHER ELEVS IN
THE WEST - CAN STAY AWAY FROM BAD VISBYS.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
COLD FRONT PUSHES SE ACROSS THE REGION TUESDAY. DEWPOINTS DROP
THROUGH THE DAY IN THE NW HALF OF THE CWA...BUT THE SE WILL STAY
VERY WARM AND HUMID THROUGH MOST OF THE AFTERNOON. PWATS STILL AOA
35 MM NEAR AND SE OF THE I-81 CORRIDOR THROUGH 18Z TUESDAY...AND
THE COMBINATION OF THE HEAT AND MOISTURE WILL HELP TO FIRE UP SFC-
BASED CAPES INTO THE 1500-2000 J/KG RANGE. EXPECT A BKN LINE OR
TWO OF SHOWERS AND PERHAPS A RUMBLE OF THUNDER ALONG THE CFRONT
FROM NEAR KELM...TO KUNV AND KJST DURING THE MIDDAY HOURS. THIS
AREA OF CONVECTION WILL LIKELY INTENSIFY INTO A BKN LINE OF STRONG
TSRA AFTER 16Z TUESDAY NEAR A KAVP TO KSEG AND KHGR LINE.

SPC/S MARGINAL RISK FOR SVR TSRA NIPS A FEW OF OUR EASTERN
COUNTIES TUESDAY...AND COULD SEE THIS BEING EXTENDED A TAD FURTHER
TO THE SW BASED MAINLY ON INSTABILITY AND A LOCALIZED LARGE HAIL
THREAT /COMPARED TO BETTER DEEP LAYER SHEAR FURTHER NORTH/.

&&

.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
AREA OF SHOWERS/TSTMS WILL BE DEPARTING LATE TUE/EARLY TUE
EVE...ASSOCIATED WITH A COLD FRONT CLEARING THE REGION.

IN IT/S WAKE...RESPECTABLE ANTICYCLONE WILL BUILD IN FROM THE WEST
WITH A PUSH OF NOTICEABLY COOLER AND DRIER AIR FILTERING IN FOR
MIDWEEK. A WEAK WAVE EJECTS EASTWARD FROM THE S PLAINS TOWARD THE
CAROLINA/S ON THU...WHILE TROUGH CONTINUES TO SPIN OVER EASTERN
CANADA. CENTRAL PA REMAINS BETWEEN THESE TWO FEATURES...WHICH WILL
KEEP US DRY. EVEN WITH NW FLOW...DAYTIME TEMPS WILL REBOUND A BIT
WARMER EACH DAY. BUT DIURNAL TEMP RANGES WILL BE FAIRLY LARGE
THANKS TO THE DRIER AIRMASS...WHICH WILL BRING CHILLY MORNINGS.
THE COLDEST CONTINUES TO LOOK LIKE THURSDAY MORNING WHERE THERE
REMAINS A RISK FOR PATCHY FROST...MAINLY OVER THE NORTH-CENTRAL
ZONES WHERE GUIDANCE IS SHOWING POSS FOR MID 30S AOA BFD /JUST IN
TIME FOR THE START OF THE GROWING SEASON/.

THE WEAK LOW OVER CAROLINAS/MID ATLANTIC REGION SLIDES OFFSHORE
FRI...WITH SPRAWLING HIGH PRESSURE AREA BUILDING IN FOR SAT/SUN.
ONCE RIDGE AXIS SLIDES BY SAT NIGHT...HUMIDITY WILL BEGIN TO
SLOWLY INCREASE ON SUNDAY WITH RISING TEMPS /AND ISOLATED
LATE DAY CONVECTION POSS/. WARMER AND MUGGIER CONDITIONS ON
MEMORIAL DAY...WITH SCATTERED TO EVEN NUMEROUS SHOWERS/TSTMS IN
THE FORECAST.

&&

.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
SCT SHRA/TSRA WILL CONTINUE TO FORM ACROSS CENTRAL PA THIS EVENING
IN UNSTABLE AIR MASS AHEAD OF APPROACHING COLD FRONT OVR THE
MIDWEST. ANY OF THESE SHRA/TSRA COULD PRODUCE BRIEF VIS
REDUCTIONS. HOWEVER...THE MAIN AVIATION CONCERN THIS EVENING WILL
BE THE DEVELOPING LOW CIGS ACROSS EASTERN PA...THE RESULT OF
MARINE AIR FLOWING OFF THE ATLANTIC OCEAN. IFR CIGS ALREADY NOTED
ACROSS NJ AT 23Z AND NEAR TERM MDL DATA SUPPORT THESE LOW CIGS
MOVING INTO KLNS BTWN 01Z-03Z AND POSSIBLY REACHING AS FAR WEST AS
KMDT/KIPT BTWN 03Z-06Z. FURTHER WEST...A PLUME OF MOISTURE AHEAD
OF APPROACHING COLD FRONT WILL ASCEND THE W MTNS...LIKELY
RESULTING IN IFR CIGS AT KBFD/KJST LATE TONIGHT. BOTH THE 15Z SREF
AND LATEST HRRR SUPPORT THIS SCENARIO. MOST FAVORABLE CONDS
OVERNIGHT SHOULD BE AT KAOO/KUNV...WHERE SIG REDUCTIONS APPEAR
UNLIKELY.

LOW CIGS ACROSS THE W MTNS AND EASTERN PA SHOULD LIFT BY LATE AM.
CAN/T RULE OUT AN ISOLD SHRA/TSRA ACROSS EASTERN PA ARND MIDDAY
WITH PASSAGE OF COLD FRONT. OTHERWISE...EXPECT A RETURN TO
WIDESPREAD VFR CONDS...AS A GUSTY WEST WIND BRINGS MUCH DRIER AIR
INTO THE REGION BEHIND THE COLD FRONT.

OUTLOOK...

WED-SAT...NO SIG WX EXPECTED.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...LAMBERT
LONG TERM...RXR
AVIATION...FITZGERALD




AREA FORECAST DISCUSSION

NWS STATE COLLEGE PA

 832 PM EDT MON MAY 18 2015

.SYNOPSIS...
A NEARLY STATIONARY...BACK DOOR COLD FRONT WILL BE LOCATED ACROSS
THE SUSQUEHANNA VALLEY TONIGHT. THIS BOUNDARY WILL COMBINE WITH AN
EXTENSIVE PLUME OF DEEP MOISTURE TO FOCUS ADDITIONAL HEAVY
SHOWERS AND THUNDERSTORMS ACROSS CENTRAL PENNSYLVANIA AND THE
SUSQUEHANNA VALLEY OVERNIGHT. A SEPARATE COLD FRONT WILL APPROACH
FROM THE UPPER MIDWEST...PUSHING SOUTHEAST ACROSS THE COMMONWEALTH
TUESDAY AND BRINGING WITH IT...ANOTHER FEW ROUNDS OF SHOWERS AND
THUNDERSTORMS TUESDAY. A COOLER AND DRY AIRMASS WILL MOVE IN
BEHIND THE COLD FRONT FOR THE MIDDLE OF THIS WEEK. MUGGINESS WILL
RETURN OVER THE MEMORIAL DAY WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
VERY HIGH PWAT AIR PARKED OVER THE AREA WILL COMBINE WITH A SLOWLY
WWD MOVING BACK DOOR COLD FRONT TO PRODUCE A FEW ADDITIONAL ROUNDS
OF SHOWERS AND THUNDERSTORMS IN MANY LOCATIONS THROUGH 06Z.

THE MAIN AREA OF CONCERN WILL BE OVER THE MIDDLE AND LOWER SUSQ
VALLEY WHERE SOME LOCATIONS ALREADY PICKED UP OVER 2 INCHES OF
RAIN TODAY /AND HIGHLY LOCALIZED 4-5 INCH AMOUNTS ACROSS NORTHERN
LEBANON AND SOUTHERN SCHUYLKILL COUNTIES...WHERE AROUND AN HOUR
OF TRAINING CELLS OCCURRED LATE IN THE DAY/.

23Z HRRR INDICATES THAT CLUSTERS OF SHRA/MULTI-CELL TSRA MOVING
STEADILY EAST WILL BE THE PRIMARY MODE OF CONVECTION THROUGH
04Z...WITH A POSSIBLE NORTH/SOUTH RIBBON OF NEARLY STATIONARY
HEAVY SHOWERS AND A FEW EMBEDDED TSRA OCCURRING ACROSS THE SUSQ
VALLEY AFTER MIDNIGHT TONIGHT.

WILL MONITOR TRENDS IN CONVECTION CLOSELY OVER THE NEXT HOUR OR
SO...FOR THE POSSIBLE ISSUANCE OF A FLASH FLOOD WATCH ACROSS
PORTIONS OF THE LOWER SUSQ VALLEY.

A RATHER MILD/MUGGY NIGHT IS IN STORE WITH LOWS EARLY TUESDAY IN
THE 60-65F RANGE FROM NORTH TO SOUTH.

FOG AND LOW CLOUDS ARE AGAIN EXPECTED OVER MOST/ALL OF THE AREA
LATE TONIGHT/EARLY TUESDAY. PERHAPS ONLY THE PLACES WHICH CAN
KEEP WIND OVER 5-6KTS THROUGH THE NIGHT - MAINLY HIGHER ELEVS IN
THE WEST - CAN STAY AWAY FROM BAD VISBYS.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
COLD FRONT PUSHES SE ACROSS THE REGION TUESDAY. DEWPOINTS DROP
THROUGH THE DAY IN THE NW HALF OF THE CWA...BUT THE SE WILL STAY
VERY WARM AND HUMID THROUGH MOST OF THE AFTERNOON. PWATS STILL AOA
35 MM NEAR AND SE OF THE I-81 CORRIDOR THROUGH 18Z TUESDAY...AND
THE COMBINATION OF THE HEAT AND MOISTURE WILL HELP TO FIRE UP SFC-
BASED CAPES INTO THE 1500-2000 J/KG RANGE. EXPECT A BKN LINE OR
TWO OF SHOWERS AND PERHAPS A RUMBLE OF THUNDER ALONG THE CFRONT
FROM NEAR KELM...TO KUNV AND KJST DURING THE MIDDAY HOURS. THIS
AREA OF CONVECTION WILL LIKELY INTENSIFY INTO A BKN LINE OF STRONG
TSRA AFTER 16Z TUESDAY NEAR A KAVP TO KSEG AND KHGR LINE.

SPC/S MARGINAL RISK FOR SVR TSRA NIPS A FEW OF OUR EASTERN
COUNTIES TUESDAY...AND COULD SEE THIS BEING EXTENDED A TAD FURTHER
TO THE SW BASED MAINLY ON INSTABILITY AND A LOCALIZED LARGE HAIL
THREAT /COMPARED TO BETTER DEEP LAYER SHEAR FURTHER NORTH/.

&&

.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
AREA OF SHOWERS/TSTMS WILL BE DEPARTING LATE TUE/EARLY TUE
EVE...ASSOCIATED WITH A COLD FRONT CLEARING THE REGION.

IN IT/S WAKE...RESPECTABLE ANTICYCLONE WILL BUILD IN FROM THE WEST
WITH A PUSH OF NOTICEABLY COOLER AND DRIER AIR FILTERING IN FOR
MIDWEEK. A WEAK WAVE EJECTS EASTWARD FROM THE S PLAINS TOWARD THE
CAROLINA/S ON THU...WHILE TROUGH CONTINUES TO SPIN OVER EASTERN
CANADA. CENTRAL PA REMAINS BETWEEN THESE TWO FEATURES...WHICH WILL
KEEP US DRY. EVEN WITH NW FLOW...DAYTIME TEMPS WILL REBOUND A BIT
WARMER EACH DAY. BUT DIURNAL TEMP RANGES WILL BE FAIRLY LARGE
THANKS TO THE DRIER AIRMASS...WHICH WILL BRING CHILLY MORNINGS.
THE COLDEST CONTINUES TO LOOK LIKE THURSDAY MORNING WHERE THERE
REMAINS A RISK FOR PATCHY FROST...MAINLY OVER THE NORTH-CENTRAL
ZONES WHERE GUIDANCE IS SHOWING POSS FOR MID 30S AOA BFD /JUST IN
TIME FOR THE START OF THE GROWING SEASON/.

THE WEAK LOW OVER CAROLINAS/MID ATLANTIC REGION SLIDES OFFSHORE
FRI...WITH SPRAWLING HIGH PRESSURE AREA BUILDING IN FOR SAT/SUN.
ONCE RIDGE AXIS SLIDES BY SAT NIGHT...HUMIDITY WILL BEGIN TO
INCREASE ON SUNDAY WITH RISING TEMPS /AND ISOLATED CONVECTION
POSS/. EVEN WARMER AND MUGGIER ON MEMORIAL DAY...WITH SCATTERED TO
EVEN NUMEROUS SHOWERS/TSTMS IN THE FORECAST.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
SCT SHRA/TSRA WILL CONTINUE TO FORM ACROSS CENTRAL PA THIS EVENING
IN UNSTABLE AIR MASS AHEAD OF APPROACHING COLD FRONT OVR THE
MIDWEST. ANY OF THESE SHRA/TSRA COULD PRODUCE BRIEF VIS
REDUCTIONS. HOWEVER...THE MAIN AVIATION CONCERN THIS EVENING WILL
BE THE DEVELOPING LOW CIGS ACROSS EASTERN PA...THE RESULT OF
MARINE AIR FLOWING OFF THE ATLANTIC OCEAN. IFR CIGS ALREADY NOTED
ACROSS NJ AT 23Z AND NEAR TERM MDL DATA SUPPORT THESE LOW CIGS
MOVING INTO KLNS BTWN 01Z-03Z AND POSSIBLY REACHING AS FAR WEST AS
KMDT/KIPT BTWN 03Z-06Z. FURTHER WEST...A PLUME OF MOISTURE AHEAD
OF APPROACHING COLD FRONT WILL ASCEND THE W MTNS...LIKELY
RESULTING IN IFR CIGS AT KBFD/KJST LATE TONIGHT. BOTH THE 15Z SREF
AND LATEST HRRR SUPPORT THIS SCENARIO. MOST FAVORABLE CONDS
OVERNIGHT SHOULD BE AT KAOO/KUNV...WHERE SIG REDUCTIONS APPEAR
UNLIKELY.

LOW CIGS ACROSS THE W MTNS AND EASTERN PA SHOULD LIFT BY LATE AM.
CAN/T RULE OUT AN ISOLD SHRA/TSRA ACROSS EASTERN PA ARND MIDDAY
WITH PASSAGE OF COLD FRONT. OTHERWISE...EXPECT A RETURN TO
WIDESPREAD VFR CONDS...AS A GUSTY WEST WIND BRINGS MUCH DRIER AIR
INTO THE REGION BEHIND THE COLD FRONT.

OUTLOOK...

WED-SAT...NO SIG WX EXPECTED.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...DANGELO/LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...LAMBERT
LONG TERM...RXR
AVIATION...FITZGERALD




AREA FORECAST DISCUSSION

NWS STATE COLLEGE PA

 756 PM EDT MON MAY 18 2015

.SYNOPSIS...
A COLD FRONT WILL PUSH ACROSS THE AREA TONIGHT AND EARLY
TUESDAY...PRECEDED BY SHOWERS AND THUNDERSTORMS. THE FRONT WILL
USHER IN A COOL...DRY AIRMASS FOR THE MIDDLE OF THE WEEK.
MUGGINESS WILL RETURN OVER THE HOLIDAY WEEKEND.

&&

.NEAR TERM /UNTIL 1 AM TUESDAY MORNING/...
VERY HIGH PWAT AIR SITTING OVER THE AREA. CAPE HAS BEEN SOMEWHAT
LIMITED UNTIL THE LAST 30 TO 60 MINUTES. THE CAP IS BROKEN AND TC
HAS BEEN PASSED. SHOWERS AND THUNDERSTORMS HAVE GROWN OVER ALMOST
ALL OF THE CWA WITH LITTLE TO NO PATTERN OR ORGANIZATION. THERE
HAS BEEN ONE BACK-BUILDING STORM IN SRN LANC CO. BUT THE HIGH
MOISTURE WILL TIELD SOME VERY HIGH RAIN RATES. WILL NEED TO KEEP
AN EYE ON AREAS WHICH RECEIVE MULTIPLE STORMS/BACKBUILD. THESE
SHOWERS WILL CONTINUE INTO THE EVENING. LATEST NAM RUN PUSHES
MOST OF THE RAIN OFF TO THE EAST OF THE SUSQ RIVER SHORTLY AFTER
1 AM.

&&

.SHORT TERM /1 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
THE FIRST NUDGE OF DRY AIR COMES IN UNDER A SHORT WAVE CURRENTLY
OVER KCVG. THIS SHOULD EFFECTIVELY END MOST OF THE SHOWERS. BUT
THE REAL COLD/DRY AIR DOES NOT ARRIVE IN THE WEST UNTIL CLOSE TO
SUNRISE TUES. THUS...A SLIGHT CHC OF A SHOWER WILL BE MENTIONED
FOR MUCH OF THE AREA OVERNIGHT - ESP IN THE EAST. DEWPOINTS DROP
THROUGH THE DAY IN THE NW HALF OF THE AREA...BUT THE SE COULD STAY
MUGGY AND THE SKY SHOULD BREAK UP LATER TONIGHT. SO SUNSHINE WILL
HEAT UP THE ERN VALLEYS. A STORM OR TWO WILL PROBABLY POP UP IN
THE HEATING OF THE DAY THERE...BUT ARRIVAL OF THE DRY AIR WILL
MAKE IT DIFFICULT TO ALLOW ANYTHING TO GROW ENOUGH IN THE WEST TO
PRECIPITATE. FOG AND LOW CLOUDS ARE AGAIN EXPECTED OVER MOST/ALL
OF THE AREA. PERHAPS ONLY THE PLACES WHICH CAN KEEP WIND OVER
5-6KTS THROUGH THE NIGHT - MAINLY HIGHER ELEVS IN THE WEST - CAN
STAY AWAY FROM BAD VISBYS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
AREA OF SHOWERS/TSTMS WILL BE DEPARTING LATE TUE/EARLY TUE
EVE...ASSOCIATED WITH A COLD FRONT CLEARING THE REGION.

IN IT/S WAKE...RESPECTABLE ANTICYCLONE WILL BUILD IN FROM THE WEST
WITH A PUSH OF NOTICEABLY COOLER AND DRIER AIR FILTERING IN FOR
MIDWEEK. A WEAK WAVE EJECTS EASTWARD FROM THE S PLAINS TOWARD THE
CAROLINA/S ON THU...WHILE TROUGH CONTINUES TO SPIN OVER EASTERN
CANADA. CENTRAL PA REMAINS BETWEEN THESE TWO FEATURES...WHICH WILL
KEEP US DRY. EVEN WITH NW FLOW...DAYTIME TEMPS WILL REBOUND A BIT
WARMER EACH DAY. BUT DIURNAL TEMP RANGES WILL BE FAIRLY LARGE
THANKS TO THE DRIER AIRMASS...WHICH WILL BRING CHILLY MORNINGS.
THE COLDEST CONTINUES TO LOOK LIKE THURSDAY MORNING WHERE THERE
REMAINS A RISK FOR PATCHY FROST...MAINLY OVER THE NORTH-CENTRAL
ZONES WHERE GUIDANCE IS SHOWING POSS FOR MID 30S AOA BFD /JUST IN
TIME FOR THE START OF THE GROWING SEASON/.

THE WEAK LOW OVER CAROLINAS/MID ATLANTIC REGION SLIDES OFFSHORE
FRI...WITH SPRAWLING HIGH PRESSURE AREA BUILDING IN FOR SAT/SUN.
ONCE RIDGE AXIS SLIDES BY SAT NIGHT...HUMIDITY WILL BEGIN TO
INCREASE ON SUNDAY WITH RISING TEMPS /AND ISOLATED CONVECTION
POSS/. EVEN WARMER AND MUGGIER ON MEMORIAL DAY...WITH SCATTERED TO
EVEN NUMEROUS SHOWERS/TSTMS IN THE FORECAST.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
SCT SHRA/TSRA WILL CONTINUE TO FORM ACROSS CENTRAL PA THIS EVENING
IN UNSTABLE AIR MASS AHEAD OF APPROACHING COLD FRONT OVR THE
MIDWEST. ANY OF THESE SHRA/TSRA COULD PRODUCE BRIEF VIS
REDUCTIONS. HOWEVER...THE MAIN AVIATION CONCERN THIS EVENING WILL
BE THE DEVELOPING LOW CIGS ACROSS EASTERN PA...THE RESULT OF
MARINE AIR FLOWING OFF THE ATLANTIC OCEAN. IFR CIGS ALREADY NOTED
ACROSS NJ AT 23Z AND NEAR TERM MDL DATA SUPPORT THESE LOW CIGS
MOVING INTO KLNS BTWN 01Z-03Z AND POSSIBLY REACHING AS FAR WEST AS
KMDT/KIPT BTWN 03Z-06Z. FURTHER WEST...A PLUME OF MOISTURE AHEAD
OF APPROACHING COLD FRONT WILL ASCEND THE W MTNS...LIKELY
RESULTING IN IFR CIGS AT KBFD/KJST LATE TONIGHT. BOTH THE 15Z SREF
AND LATEST HRRR SUPPORT THIS SCENARIO. MOST FAVORABLE CONDS
OVERNIGHT SHOULD BE AT KAOO/KUNV...WHERE SIG REDUCTIONS APPEAR
UNLIKELY.

LOW CIGS ACROSS THE W MTNS AND EASTERN PA SHOULD LIFT BY LATE AM.
CAN/T RULE OUT AN ISOLD SHRA/TSRA ACROSS EASTERN PA ARND MIDDAY
WITH PASSAGE OF COLD FRONT. OTHERWISE...EXPECT A RETURN TO
WIDESPREAD VFR CONDS...AS A GUSTY WEST WIND BRINGS MUCH DRIER AIR
INTO THE REGION BEHIND THE COLD FRONT.

OUTLOOK...

WED-SAT...NO SIG WX EXPECTED.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...DANGELO
LONG TERM...RXR
AVIATION...FITZGERALD



AREA FORECAST DISCUSSION

NWS GREENVILLE-SPARTANBURG SC

 154 PM EDT SUN MAY 17 2015

.SYNOPSIS...
BERMUDA HIGH PRESSURE WILL PERSIST OVER THE REGION EARLY THIS WEEK.
A COLD FRONT WILL APPROACH LATE MONDAY AND MOVE OVER THE AREA ON
TUESDAY...BRINGING INCREASED PRECIPITATION CHANCES TO BOTH THE
MOUNTAINS AND PIEDMONT. SLIGHTLY COOLER AND DRIER HIGH PRESSURE WILL
RETURN ON WEDNESDAY. SOMEWHAT UNSETTLED WEATHER WILL RETURN LATE IN
THE WEEK WITH A STATIONARY FRONT SETTING UP OVER THE REGION.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 150 PM...WESTERN CAROLINA ZONES WILL GENERALLY REMAIN UNDER A
BKN TO OVC DECK OF MID AND HIGH CLOUDS THROUGH THE REST OF THE
AFTERNOON. LATEST RADAR IMAGES INDICATE A FEW SHRA ACROSS THE
WESTERN NC MTNS AND EXTREME NE GA...MORE CONVECTIVE SHRA OVER THE
NRNMOST NC MTNS. IT APPEARS THAT MARGINAL INSTABILITY AND LATEST
GUIDANCE SUPPORT A CHC LATE AFTERNOON STORMS ACROSS THE MTNS AND
ADJACENT FOOTHILLS. I WILL UPDATE THE FORECAST TO LATEST CONVECTIVE
TIMING...ADJUST SKY TO SAT...AND TEMPS TO OBS.

AS OF 820 AM...REGIONAL RADAR CONTINUES TO INDICATE A FEW PATCHES OF
LIGHT RETURNS ACROSS THE WESTERN CAROLINA AND GEORGIA MTNS. I WILL
ISSUE A QUICK UPDATE TO ADJUST POP...SKY...AND TEMPS TO LATEST
TRENDS.

AS OF 650 AM EDT...EARLY RADAR RETURNS AROUND DAYBREAK ARE WRAPPING
SCATTERED SHOWERS INTO THE FAR SW MTNS. WILL BOOST POPS SLIGHTLY IN
THAT AREA...BUT THE FORECAST TRENDS REMAIN ON TRACK OTHERWISE.

THE HIGHLY AMPLIFIED UPPER FLOW PATTERN OVER THE CONUS WILL KEEP A
RIDGE IN PLACE OVER THE SE THROUGH THE NEAR TERM. PLENTY OF MID AND
HIGH DEBRIS CLOUDS WILL RIDE OVER THE RIDGE AXIS ACROSS THE
AREA...BUT WITH ENOUGH BREAKS TO PERMIT MAX TEMPS TO CLIMB TO ABOUT
5 DEGREES ABOVE CLIMO IN MOST AREAS...AND TO FOSTER A HEALTHY
CUMULUS FIELD. THE NUMERICAL MODELS KEEP THE DEEPEST MOISTURE AND
BEST FORCING FROM S TO SW UPSLOPE FLOW AND LOW LEVEL WIND
CONVERGENCE CONFINED TO THE SPINE OF THE SOUTHERN APPALACHIANS THIS
AFTERNOON AND EVENING. WRN MTN INSTABILITY WILL INCREASE THROUGH THE
DAY...WITH SBCAPE VALUES RUNNING 2000 J/KG OR GREATER BY LATE
AFTERNOON NEAR THE TN BORDER. NAM AND RAP PROFILES HAVE MUCH MORE
LIMITED INSTABILITY EAST OF THE MOUNTAINS...AND THE NAM QPF
PRESENTATION OF MAINLY MTN COVERAGE FOR LATE DAY IS PREFERRED. WILL
THUS FEATURE LIKELY POPS THIS AFTN NEAR THE TN BORDER AND TAPER DOWN
TO BELOW SLIGHT CHANCE FOR CLT METRO.

CONVECTIVE COVERAGE SHOULD WANE QUICKLY THIS EVENING...BUT WILL KEEP
ISOLD SHOWER COVERAGE GOING THROUGH THE NIGHT IN DEVELOPING LIGHT
WESTERLY UPSLOPE FLOW. MILD MINS SHOULD BE ANOTHER 1 TO 2 DEGREES
WARMER THAN THIS MORNING.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 200 AM SUNDAY...UPPER HEIGHTS WILL FALL MONDAY OVER THE NERN
CONUS AS LOW PRESSURE MOVES ACRS THE GREAT LAKES. LATEST MODEL PROGS
SHOW LITTLE IMPACT IN THE HEIGHT FIELD OVER THE SOUTHEAST...BUT STILL
SHOW LLVL FLOW VEERING TO NWLY AS THE DAY PROGRESSES. WITHOUT GULF
FLOW ENHANCING WARM/MOIST ADVECTION THE THERMODYNAMIC CONDITIONS WILL
LIKELY BE SIMILAR TO SUNDAY...EXCEPT THAT THE WEAKER RIDGE WILL ALLOW
DEEP CONVECTION OVER THE PIEDMONT AS WELL AS OVER THE MTNS. DEEP
SHEAR REMAINS SMALL. SEVERE DOWNBURST WINDS CANNOT BE TOTALLY RULED
OUT BUT WILL LIKELY REMAIN ISOLATED. PWAT VALUES WELL ABOVE CLIMO AND
SHORT STORM MOTION VECTORS IMPLY HEAVY RAIN WILL BE A MORE LIKELY
THREAT.

AS THE LOW MOVES EWD INTO QUEBEC MON NIGHT...ITS COLD FRONT WILL
CROSS THE SRN APPALACHIANS. EAST OF THE MTNS CONVECTION SHOULD
GRADUALLY WANE WITH THE LOSS OF DIURNAL HEATING...BUT STRENGTHENING
UPSLOPE FLOW MAY ALLOW ACTIVITY TO CONTINUE OVERNIGHT NEAR THE TENN
BORDER. LATER ON TUE THE FRONT WILL PROGRESS ACRS THE CWFA. OVER THE
HIGHER TERRAIN SLIGHTLY COOLER TEMPS AND AN EARLIER THAN NORMAL PEAK
IN CONVECTIVE ACTIVITY ARE EXPECTED. THE PIEDMONT HOWEVER LOOKS TO
SEE A DAY VERY MUCH LIKE MONDAY...PERHAPS EVEN WITH BETTER COVERAGE
DUE TO FRONTAL CONVERGENCE OR MTN LEE TROUGHING. THE THREATS WILL BE
GENERALLY THE SAME.

MAX TEMPS MON/TUE WILL BE AROUND 5 DEG ABOVE CLIMO IN THE MTNS AND
NEAR 10 ABOVE IN THE PIEDMONT. CLOUD COVER WILL HELP KEEP MINS 7-10
DEG ABOVE CLIMO THROUGHOUT THE AREA...BUT TREND COOLER FROM TUE TO
WED MRNG AS THE CANADIAN AIRMASS SETTLES IN.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 130 PM EDT SUNDAY...THE MEDIUM RANGE FCST BEGINS AT 00Z ON
THURSDAY WITH A FLAT UPPER RIDGE OVER THE SE CONUS AND A BROAD UPPER
TROF DIGGING DOWN OVER EXTREME SE CANADA. THIS MOSTLY ZONAL UPPER
PATTERN IS EXPECTED TO PERSIST OVER OUR REGION INTO SAT...AFTER
WHICH...HEIGHTS BEGIN TO RISE AS UPPER RIDGING FROM THE WEST SPREADS
OVER THE REGION AND REMAINS IN PLACE THRU DAY 7.

AT THE SFC...THE REMNANTS OF THE POST FRONTAL CANADIAN HIGH WILL BE
LINGERING OVER THE AREA AT THE START OF THE PERIOD. AS THE PRESSURE
GRADIENT WEAKENS FURTHER...NEAR SFC WINDS WILL BECOME MORE WEAK AND
VARIABLE ON THURS AND REMAIN SO WELL INTO FRI. IN THE
MEANTIME...ANOTHER SFC HIGH WILL WILL MAKE ITS WAY SOUTHWARD FROM
CANADA ON FRI AND SETTLE TO OUR NORTH BY EARLY SAT. THIS SHOULD
CAUSE LOW LVL FLOW TO BECOME MORE NLY AND THEN NELY BY SAT MORNING.
AS WE MOVE INTO SUN...THE CENTER OF THE HIGH BEGINS TO SLIDE OFF THE
EAST COAST AND THE FLOW BECOMES MORE SELY WITH DEEPER MOISTURE
SPREADING BACK OVER THE FCST AREA. AS FOR THE SENSIBLE FCST...BOTH
THURS AND FRI WILL BE CHARACTERIZED BY SLIGHT CHANCE TO LOW END
CHANCE SH AND TS EACH DAY WITH THE BEST CHANCES OVER THE HIGHER
TERRAIN. SAT SHOULD BE MOSTLY DRY WITH HIGH SLIDING BY TO OUR NORTH.
CHANCES FOR MORE WIDESPREAD CONVECTION WILL INCREASE AGAIN ON SUN AS
MORE MOIST...SELY FLOW SPREADS BACK OVER THE REGION. TEMPS WILL
REMAIN ABOVE CLIMO EACH DAY WITH SOME COOLING ON SAT.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
AT KCLT...PATCHES OF MID AND HIGH CLOUDS WILL CONTINUE TO DRIFT OVER
THE TERMINAL THROUGH THE OVERNIGHT HOURS. CU IS EXPECTED TO INCREASE
IN COVERAGE THROUGH THE REST OF THE AFTERNOON...PEAKING WITH SCT
COVERAGE AROUND 050 KFT. HOWEVER...CAPE ACROSS THE REGION IS
EXPECTED TO BE CAPPED AROUND 500 J/KG DUE TO WARM MID LEVEL
TEMPERATURES. LATEST SATELLITE TRENDS AND CAMS INDICATE THAT DEEP
CONVECTION IS NOT FAVORED OVER CLT. THEREFORE...I WILL KEEP
CONDITIONS DRY AND VFR. WINDS SHOULD REMAIN LESS THAN 10 KTS FROM THE
SOUTHWEST THROUGH TONIGHT. AFTER SUNRISE MONDAY...WINDS WILL VEER
FROM FROM SSW AS A LEE TROF FORMS. CU SHOULD DEVELOP BY MID MORNING
WITH BASES AROUND 060 KFT.

ELSEWHERE...WESTERN CAROLINA TERMINALS WILL GENERALLY REMAIN UNDER A
BKN TO OVC DECK OF MID AND HIGH CLOUDS THROUGH THE REST OF THE
AFTERNOON. LATEST RADAR IMAGES INDICATE A FEW SHRA ACROSS THE
WESTERN NC MTNS AND EXTREME NE GA...MORE CONVECTIVE SHRA OVER THE
NRNMOST NC MTNS. IT APPEARS THAT MARGINAL INSTABILITY AND LATEST
GUIDANCE SUPPORT A LATE AFTERNOON TEMPO AT KAVL AND KHKY FOR TSRA.
OTHERWISE...VCSH WILL BE FEATURED IN THE TAFS INTO THIS EVENING.
GUIDANCE AND RECENT MORNING TRENDS INDICATE VFR CONDITIONS OVER DRY
GROUND. BASED ON LOWER VALUES OF CONDENSATION PRESSURE DEFICITS
FROM THE NAM...I WILL INDICATE 4 SM BR BETWEEN 11Z TO 13Z AT KAVL.
AFTER SUNRISE MONDAY...WINDS WILL VEER FROM FROM SSW AS A LEE TROF
FORMS. CU SHOULD DEVELOP BY MID MORNING WITH BASES AROUND 060 KFT.

OUTLOOK...THE REGION WILL REMAIN WITHIN A PLUME OF MOISTURE THROUGH
MID WEEK. MORNING FOG AND STRATUS WILL BE POSSIBLE EACH MORNING
ABOVE WET GROUND. OTHERWISE...EXPECTING LIGHT WINDS WITH AFTERNOON
AND EVENING TSRA. THE MID WEEK PASSAGE OF A COLD FRONT SHOULD
PROVIDE FAIR CONDITIONS LATE IN THE WORK WEEK.

CONFIDENCE TABLE...

            18-24Z        00-06Z        06-12Z        12-18Z
KCLT       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGSP       HIGH 100%     HIGH  92%     HIGH 100%     HIGH 100%
KAVL       HIGH 100%     HIGH 100%     HIGH  97%     HIGH 100%
KHKY       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGMU       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAND       HIGH 100%     HIGH  92%     HIGH 100%     HIGH 100%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...JPT
NEAR TERM...NED
SHORT TERM...WIMBERLEY
LONG TERM...JPT
AVIATION...NED



AREA FORECAST DISCUSSION

NWS GREENVILLE-SPARTANBURG SC

 822 AM EDT SUN MAY 17 2015

.SYNOPSIS...
BERMUDA HIGH PRESSURE WILL PERSIST OVER THE SOUTHEAST EARLY
THIS WEEK. A COLD FRONT WILL APPROACH LATE MONDAY AND MOVE THROUGH
ON TUESDAY...BRINGING PRECIPITATION CHANCES TO BOTH THE MOUNTAINS
AND PIEDMONT. SLIGHTLY COOLER AND DRIER HIGH PRESSURE WILL RETURN
WEDNESDAY. SOMEWHAT UNSETTLED WEATHER WILL RETURN LATE IN THE WEEK
WITH A STATIONARY FRONT SETTING UP OVER THE REGION.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 820 AM...REGIONAL RADAR CONTINUES TO INDICATE A FEW PATCHES
OF LIGHT RETURNS ACROSS THE WESTERN CAROLINA AND GEORGIA MTNS. I
WILL ISSUE A QUICK UPDATE TO ADJUST POP...SKY...AND TEMPS TO
LATEST TRENDS.

AS OF 650 AM EDT...EARLY RADAR RETURNS AROUND DAYBREAK ARE WRAPPING
SCATTERED SHOWERS INTO THE FAR SW MTNS. WILL BOOST POPS SLIGHTLY IN
THAT AREA...BUT THE FORECAST TRENDS REMAIN ON TRACK OTHERWISE.

THE HIGHLY AMPLIFIED UPPER FLOW PATTERN OVER THE CONUS WILL KEEP A
RIDGE IN PLACE OVER THE SE THROUGH THE NEAR TERM. PLENTY OF MID AND
HIGH DEBRIS CLOUDS WILL RIDE OVER THE RIDGE AXIS ACROSS THE
AREA...BUT WITH ENOUGH BREAKS TO PERMIT MAX TEMPS TO CLIMB TO ABOUT
5 DEGREES ABOVE CLIMO IN MOST AREAS...AND TO FOSTER A HEALTHY
CUMULUS FIELD. THE NUMERICAL MODELS KEEP THE DEEPEST MOISTURE AND
BEST FORCING FROM S TO SW UPSLOPE FLOW AND LOW LEVEL WIND
CONVERGENCE CONFINED TO THE SPINE OF THE SOUTHERN APPALACHIANS THIS
AFTERNOON AND EVENING. WRN MTN INSTABILITY WILL INCREASE THROUGH THE
DAY...WITH SBCAPE VALUES RUNNING 2000 J/KG OR GREATER BY LATE
AFTERNOON NEAR THE TN BORDER. NAM AND RAP PROFILES HAVE MUCH MORE
LIMITED INSTABILITY EAST OF THE MOUNTAINS...AND THE NAM QPF
PRESENTATION OF MAINLY MTN COVERAGE FOR LATE DAY IS PREFERRED. WILL
THUS FEATURE LIKELY POPS THIS AFTN NEAR THE TN BORDER AND TAPER DOWN
TO BELOW SLIGHT CHANCE FOR CLT METRO.

CONVECTIVE COVERAGE SHOULD WANE QUICKLY THIS EVENING...BUT WILL KEEP
ISOLD SHOWER COVERAGE GOING THROUGH THE NIGHT IN DEVELOPING LIGHT
WESTERLY UPSLOPE FLOW. MILD MINS SHOULD BE ANOTHER 1 TO 2 DEGREES
WARMER THAN THIS MORNING.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 200 AM SUNDAY...UPPER HEIGHTS WILL FALL MONDAY OVER THE NERN
CONUS AS LOW PRESSURE MOVES ACRS THE GREAT LAKES. LATEST MODEL PROGS
SHOW LITTLE IMPACT IN THE HEIGHT FIELD OVER THE SOUTHEAST...BUT STILL
SHOW LLVL FLOW VEERING TO NWLY AS THE DAY PROGRESSES. WITHOUT GULF
FLOW ENHANCING WARM/MOIST ADVECTION THE THERMODYNAMIC CONDITIONS WILL
LIKELY BE SIMILAR TO SUNDAY...EXCEPT THAT THE WEAKER RIDGE WILL ALLOW
DEEP CONVECTION OVER THE PIEDMONT AS WELL AS OVER THE MTNS. DEEP
SHEAR REMAINS SMALL. SEVERE DOWNBURST WINDS CANNOT BE TOTALLY RULED
OUT BUT WILL LIKELY REMAIN ISOLATED. PWAT VALUES WELL ABOVE CLIMO AND
SHORT STORM MOTION VECTORS IMPLY HEAVY RAIN WILL BE A MORE LIKELY
THREAT.

AS THE LOW MOVES EWD INTO QUEBEC MON NIGHT...ITS COLD FRONT WILL
CROSS THE SRN APPALACHIANS. EAST OF THE MTNS CONVECTION SHOULD
GRADUALLY WANE WITH THE LOSS OF DIURNAL HEATING...BUT STRENGTHENING
UPSLOPE FLOW MAY ALLOW ACTIVITY TO CONTINUE OVERNIGHT NEAR THE TENN
BORDER. LATER ON TUE THE FRONT WILL PROGRESS ACRS THE CWFA. OVER THE
HIGHER TERRAIN SLIGHTLY COOLER TEMPS AND AN EARLIER THAN NORMAL PEAK
IN CONVECTIVE ACTIVITY ARE EXPECTED. THE PIEDMONT HOWEVER LOOKS TO
SEE A DAY VERY MUCH LIKE MONDAY...PERHAPS EVEN WITH BETTER COVERAGE
DUE TO FRONTAL CONVERGENCE OR MTN LEE TROUGHING. THE THREATS WILL BE
GENERALLY THE SAME.

MAX TEMPS MON/TUE WILL BE AROUND 5 DEG ABOVE CLIMO IN THE MTNS AND
NEAR 10 ABOVE IN THE PIEDMONT. CLOUD COVER WILL HELP KEEP MINS 7-10
DEG ABOVE CLIMO THROUGHOUT THE AREA...BUT TREND COOLER FROM TUE TO
WED MRNG AS THE CANADIAN AIRMASS SETTLES IN.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 300 AM SUNDAY...HIGH PRESSURE BUILDS INTO THE OH/TN VALLEYS WED
PUSHING THE COLD FRONT THRU OUR AREA...WHICH THEN STALLS. GFS AND EC
HAVE PREVIOUSLY DIFFERED ON WHETHER THE FRONT WOULD CLEAR THE AREA
BEFORE BECOMING STATIONARY...BUT HAVE COME CLOSER IN LINE AND SUGGEST
IT WILL DO SO NEAR OUR SRN CWFA BORDER. WITH A TROUGH PERSISTING OVER
ERN CANADA....CYCLONIC UPPER FLOW WILL BE PRESENT ALOFT OVER THE CWFA
POTENTIALLY ENHANCING ANY BAROCLINIC FORCING ASSOCIATED WITH THE
BOUNDARY. A CUTOFF UPPER LOW MOVING IN FROM THE PACIFIC WILL SPIN UP
A NEW LOW OVER THE ROCKIES SATURDAY...LIFTING THE STATIONARY FRONT
NWD AGAIN. LOW CHANCES OF PRECIP RETURN THU AND PERIODICALLY CONTINUE
THRU THE WEEKEND...WITH LOW CONFIDENCE IN LIGHT OF MODEL DIFFERENCES
IN TIMING THE UPPER FEATURES WHICH INTERACT WITH THE BOUNDARY...AND
IN THE PLACEMENT OF THE BOUNDARY ITSELF...SINCE AREAS ON ITS WARM
SIDE ARE LIKELY TO SEE SOME DIURNAL CONVECTION. TEMPS COOL SLIGHTLY
BY THU...REMAINING JUST ABOVE CLIMO FOR MINS/MAXES THRU THE END OF
THE PERIOD.

&&

.AVIATION /13Z SUNDAY THROUGH THURSDAY/...
AT KCLT...MAINLY MID AND HIGH CLOUDS WILL DRIFT THROUGH THE RIDGE
AXIS TO HIGH PROVIDE HIGH LEVEL CIGS THROUGH THE PERIOD...BUT A
HEALTHY CUMULUS FIELD SHOULD DEVELOP ONCE AGAIN AROUND 5 KFT WITH
DAYTIME HEATING. THE MODEL PROFILES...ESPECIALLY THE RAP...ALSO
SUGGEST THAT A BRIEF PERIOD OF LOWER STRATUS COULD DEVELOP THROUGH
13Z...BUT THIS REMAINS ABSENT FROM THE MOS GUIDANCE. WILL CONTINUE
TO FEATURE ONLY A SCATTERED MVFR LEVEL LOWER CLOUD LAYER STARTING AT
12Z AND LASTING THROUGH MID MORNING. WARM TEMPERATURES ALOFT UNDER
THE RIDGE WILL LIMIT INSTABILITY AND LITTLE IN THE WAY OF CONVECTIVE
TRIGGERS WILL BE FOUND EAST OF THE MTNS THIS AFTN/EVENING. EXPECT
LIGHT S TO SW WINDS THROUGHOUT AT LESS THAN 10 KT.

ELSEWHERE...MAINLY ALTOCUMULUS AND CIRRUS CEILINGS ARE EXPECTED THIS
MORNING...BUT WITH A HEALTHY CUMULUS FIELD DEVELOPING WITH HEATING
TO PRODUCE SOME VFR CIGS AT 4 TO 6 KFT ACROSS THE MTNS AND FOOTHILLS
THROUGH THE DAY. THE DEEPER MOISTURE AND BEST FORCING FROM UPSLOPE
AND LOW LEVEL WIND CONVERGENCE WILL BE FOUND OVER THE WRN MTNS AND
ALONG THE RIDGE TOPS TODAY...WITH KAVL STANDING THE BEST CHANCE OF
AN AFTN/EVENING TSRA. WILL FEATURE VCSH WITH AFTN PROB30 TSRA AT
KAVL...AND PROB30 TSRA AT KHKY...BUT KEEP THE UPSTATE TAF SITES DRY
WITH MORE LIMITED INSTABILITY EXPECTED IN THE PROFILES. WINDS WILL
BE LIGHT S TO SW THROUGHOUT AT 10 KT OR LESS THROUGH THE PERIOD.

OUTLOOK...DEEPER MOISTURE WILL ARRIVE IN THE APPALACHIANS MON
THROUGH TUE AS A COLD FRONT APPROACHES FROM THE W. THE FRONT WILL
SETTLE SOUTHEAST OF THE AREA ON WEDNESDAY TO PERMIT BRIEF DRYING MID
WEEK. UNTIL THEN...DIURNAL SHOWERS AND THUNDERSTORMS WILL
FORM...WITH THE BEST COVERAGE OVER THE MTNS...WITH MORNING FOG
LIKELY IN AREAS THAT RECEIVE RAINFALL.

CONFIDENCE TABLE...

            12-18Z        18-24Z        00-06Z        06-12Z
KCLT       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAVL       HIGH  97%     HIGH 100%     HIGH 100%     HIGH  91%
KHKY       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGMU       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAND       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...WIMBERLEY
NEAR TERM...NED
SHORT TERM...WIMBERLEY
LONG TERM...WIMBERLEY
AVIATION...HG



AREA FORECAST DISCUSSION

NWS GREENVILLE-SPARTANBURG SC

 708 AM EDT SUN MAY 17 2015

.SYNOPSIS...
BERMUDA HIGH PRESSURE WILL PERSIST OVER THE SOUTHEAST EARLY
THIS WEEK. A COLD FRONT WILL APPROACH LATE MONDAY AND MOVE THROUGH
ON TUESDAY...BRINGING PRECIPITATION CHANCES TO BOTH THE MOUNTAINS
AND PIEDMONT. SLIGHTLY COOLER AND DRIER HIGH PRESSURE WILL RETURN
WEDNESDAY. SOMEWHAT UNSETTLED WEATHER WILL RETURN LATE IN THE WEEK
WITH A STATIONARY FRONT SETTING UP OVER THE REGION.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 650 AM EDT...EARLY RADAR RETURNS AROUND DAYBREAK ARE WRAPPING
SCATTERED SHOWERS INTO THE FAR SW MTNS. WILL BOOST POPS SLIGHTLY IN
THAT AREA...BUT THE FORECAST TRENDS REMAIN ON TRACK OTHERWISE.

THE HIGHLY AMPLIFIED UPPER FLOW PATTERN OVER THE CONUS WILL KEEP A
RIDGE IN PLACE OVER THE SE THROUGH THE NEAR TERM. PLENTY OF MID AND
HIGH DEBRIS CLOUDS WILL RIDE OVER THE RIDGE AXIS ACROSS THE
AREA...BUT WITH ENOUGH BREAKS TO PERMIT MAX TEMPS TO CLIMB TO ABOUT
5 DEGREES ABOVE CLIMO IN MOST AREAS...AND TO FOSTER A HEALTHY
CUMULUS FIELD. THE NUMERICAL MODELS KEEP THE DEEPEST MOISTURE AND
BEST FORCING FROM S TO SW UPSLOPE FLOW AND LOW LEVEL WIND
CONVERGENCE CONFINED TO THE SPINE OF THE SOUTHERN APPALACHIANS THIS
AFTERNOON AND EVENING. WRN MTN INSTABILITY WILL INCREASE THROUGH THE
DAY...WITH SBCAPE VALUES RUNNING 2000 J/KG OR GREATER BY LATE
AFTERNOON NEAR THE TN BORDER. NAM AND RAP PROFILES HAVE MUCH MORE
LIMITED INSTABILITY EAST OF THE MOUNTAINS...AND THE NAM QPF
PRESENTATION OF MAINLY MTN COVERAGE FOR LATE DAY IS PREFERRED. WILL
THUS FEATURE LIKELY POPS THIS AFTN NEAR THE TN BORDER AND TAPER DOWN
TO BELOW SLIGHT CHANCE FOR CLT METRO.

CONVECTIVE COVERAGE SHOULD WANE QUICKLY THIS EVENING...BUT WILL KEEP
ISOLD SHOWER COVERAGE GOING THROUGH THE NIGHT IN DEVELOPING LIGHT
WESTERLY UPSLOPE FLOW. MILD MINS SHOULD BE ANOTHER 1 TO 2 DEGREES
WARMER THAN THIS MORNING.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 200 AM SUNDAY...UPPER HEIGHTS WILL FALL MONDAY OVER THE NERN
CONUS AS LOW PRESSURE MOVES ACRS THE GREAT LAKES. LATEST MODEL PROGS
SHOW LITTLE IMPACT IN THE HEIGHT FIELD OVER THE SOUTHEAST...BUT STILL
SHOW LLVL FLOW VEERING TO NWLY AS THE DAY PROGRESSES. WITHOUT GULF
FLOW ENHANCING WARM/MOIST ADVECTION THE THERMODYNAMIC CONDITIONS WILL
LIKELY BE SIMILAR TO SUNDAY...EXCEPT THAT THE WEAKER RIDGE WILL ALLOW
DEEP CONVECTION OVER THE PIEDMONT AS WELL AS OVER THE MTNS. DEEP
SHEAR REMAINS SMALL. SEVERE DOWNBURST WINDS CANNOT BE TOTALLY RULED
OUT BUT WILL LIKELY REMAIN ISOLATED. PWAT VALUES WELL ABOVE CLIMO AND
SHORT STORM MOTION VECTORS IMPLY HEAVY RAIN WILL BE A MORE LIKELY
THREAT.

AS THE LOW MOVES EWD INTO QUEBEC MON NIGHT...ITS COLD FRONT WILL
CROSS THE SRN APPALACHIANS. EAST OF THE MTNS CONVECTION SHOULD
GRADUALLY WANE WITH THE LOSS OF DIURNAL HEATING...BUT STRENGTHENING
UPSLOPE FLOW MAY ALLOW ACTIVITY TO CONTINUE OVERNIGHT NEAR THE TENN
BORDER. LATER ON TUE THE FRONT WILL PROGRESS ACRS THE CWFA. OVER THE
HIGHER TERRAIN SLIGHTLY COOLER TEMPS AND AN EARLIER THAN NORMAL PEAK
IN CONVECTIVE ACTIVITY ARE EXPECTED. THE PIEDMONT HOWEVER LOOKS TO
SEE A DAY VERY MUCH LIKE MONDAY...PERHAPS EVEN WITH BETTER COVERAGE
DUE TO FRONTAL CONVERGENCE OR MTN LEE TROUGHING. THE THREATS WILL BE
GENERALLY THE SAME.

MAX TEMPS MON/TUE WILL BE AROUND 5 DEG ABOVE CLIMO IN THE MTNS AND
NEAR 10 ABOVE IN THE PIEDMONT. CLOUD COVER WILL HELP KEEP MINS 7-10
DEG ABOVE CLIMO THROUGHOUT THE AREA...BUT TREND COOLER FROM TUE TO
WED MRNG AS THE CANADIAN AIRMASS SETTLES IN.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 300 AM SUNDAY...HIGH PRESSURE BUILDS INTO THE OH/TN VALLEYS WED
PUSHING THE COLD FRONT THRU OUR AREA...WHICH THEN STALLS. GFS AND EC
HAVE PREVIOUSLY DIFFERED ON WHETHER THE FRONT WOULD CLEAR THE AREA
BEFORE BECOMING STATIONARY...BUT HAVE COME CLOSER IN LINE AND SUGGEST
IT WILL DO SO NEAR OUR SRN CWFA BORDER. WITH A TROUGH PERSISTING OVER
ERN CANADA....CYCLONIC UPPER FLOW WILL BE PRESENT ALOFT OVER THE CWFA
POTENTIALLY ENHANCING ANY BAROCLINIC FORCING ASSOCIATED WITH THE
BOUNDARY. A CUTOFF UPPER LOW MOVING IN FROM THE PACIFIC WILL SPIN UP
A NEW LOW OVER THE ROCKIES SATURDAY...LIFTING THE STATIONARY FRONT
NWD AGAIN. LOW CHANCES OF PRECIP RETURN THU AND PERIODICALLY CONTINUE
THRU THE WEEKEND...WITH LOW CONFIDENCE IN LIGHT OF MODEL DIFFERENCES
IN TIMING THE UPPER FEATURES WHICH INTERACT WITH THE BOUNDARY...AND
IN THE PLACEMENT OF THE BOUNDARY ITSELF...SINCE AREAS ON ITS WARM
SIDE ARE LIKELY TO SEE SOME DIURNAL CONVECTION. TEMPS COOL SLIGHTLY
BY THU...REMAINING JUST ABOVE CLIMO FOR MINS/MAXES THRU THE END OF
THE PERIOD.

&&

.AVIATION /11Z SUNDAY THROUGH THURSDAY/...
AT KCLT...MAINLY MID AND HIGH CLOUDS WILL DRIFT THROUGH THE RIDGE
AXIS TO HIGH PROVIDE HIGH LEVEL CIGS THROUGH THE PERIOD...BUT A
HEALTHY CUMULUS FIELD SHOULD DEVELOP ONCE AGAIN AROUND 5 KFT WITH
DAYTIME HEATING. THE MODEL PROFILES...ESPECIALLY THE RAP...ALSO
SUGGEST THAT A BRIEF PERIOD OF LOWER STRATUS COULD DEVELOP THROUGH
13Z...BUT THIS REMAINS ABSENT FROM THE MOS GUIDANCE. WILL CONTINUE
TO FEATURE ONLY A SCATTERED MVFR LEVEL LOWER CLOUD LAYER STARTING AT
12Z AND LASTING THROUGH MID MORNING. WARM TEMPERATURES ALOFT UNDER
THE RIDGE WILL LIMIT INSTABILITY AND LITTLE IN THE WAY OF CONVECTIVE
TRIGGERS WILL BE FOUND EAST OF THE MTNS THIS AFTN/EVENING. EXPECT
LIGHT S TO SW WINDS THROUGHOUT AT LESS THAN 10 KT.

ELSEWHERE...MAINLY ALTOCUMULUS AND CIRRUS CEILINGS ARE EXPECTED THIS
MORNING...BUT WITH A HEALTHY CUMULUS FIELD DEVELOPING WITH HEATING
TO PRODUCE SOME VFR CIGS AT 4 TO 6 KFT ACROSS THE MTNS AND FOOTHILLS
THROUGH THE DAY. THE DEEPER MOISTURE AND BEST FORCING FROM UPSLOPE
AND LOW LEVEL WIND CONVERGENCE WILL BE FOUND OVER THE WRN MTNS AND
ALONG THE RIDGE TOPS TODAY...WITH KAVL STANDING THE BEST CHANCE OF
AN AFTN/EVENING TSRA. WILL FEATURE VCSH WITH AFTN PROB30 TSRA AT
KAVL...AND PROB30 TSRA AT KHKY...BUT KEEP THE UPSTATE TAF SITES DRY
WITH MORE LIMITED INSTABILITY EXPECTED IN THE PROFILES. WINDS WILL
BE LIGHT S TO SW THROUGHOUT AT 10 KT OR LESS THROUGH THE PERIOD.

OUTLOOK...DEEPER MOISTURE WILL ARRIVE IN THE APPALACHIANS MON
THROUGH TUE AS A COLD FRONT APPROACHES FROM THE W. THE FRONT WILL
SETTLE SOUTHEAST OF THE AREA ON WEDNESDAY TO PERMIT BRIEF DRYING MID
WEEK. UNTIL THEN...DIURNAL SHOWERS AND THUNDERSTORMS WILL
FORM...WITH THE BEST COVERAGE OVER THE MTNS...WITH MORNING FOG
LIKELY IN AREAS THAT RECEIVE RAINFALL.

CONFIDENCE TABLE...

            11-17Z        17-23Z        23-05Z        05-06Z
KCLT       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAVL       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KHKY       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGMU       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAND       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...WIMBERLEY
NEAR TERM...HG
SHORT TERM...WIMBERLEY
LONG TERM...WIMBERLEY
AVIATION...HG




AREA FORECAST DISCUSSION

NWS GREENVILLE-SPARTANBURG SC

 455 AM EDT SUN MAY 17 2015

.SYNOPSIS...
BERMUDA HIGH PRESSURE WILL PERSIST OVER THE SOUTHEAST EARLY
THIS WEEK. A COLD FRONT WILL APPROACH LATE MONDAY AND MOVE THROUGH
ON TUESDAY...BRINGING PRECIPITATION CHANCES TO BOTH THE MOUNTAINS
AND PIEDMONT. SLIGHTLY COOLER AND DRIER HIGH PRESSURE WILL RETURN
WEDNESDAY. SOMEWHAT UNSETTLED WEATHER WILL RETURN LATE IN THE WEEK
WITH A STATIONARY FRONT SETTING UP OVER THE REGION.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 445 AM EDT...HOURLY TEMPERATURE TRENDS WERE ADJUSTED EARLY
THIS MORNING FOR SFC TEMPS COOLING A BIT MORE SLOWLY THAN GUIDANCE
GIVEN THE PASSING MID AND HIGH LEVEL CLOUD COVER.

OTHERWISE...THE HIGHLY AMPLIFIED UPPER FLOW PATTERN OVER THE CONUS
WILL KEEP A RIDGE IN PLACE OVER THE SE THROUGH THE NEAR TERM. PLENTY
OF MID AND HIGH DEBRIS CLOUDS WILL RIDE OVER THE RIDGE AXIS ACROSS
THE AREA...BUT WITH ENOUGH BREAKS TO PERMIT MAX TEMPS TO CLIMB TO
ABOUT 5 DEGREES ABOVE CLIMO IN MOST AREAS...AND TO FOSTER A HEALTHY
CUMULUS FIELD. THE NUMERICAL MODELS KEEP THE DEEPEST MOISTURE AND
BEST FORCING FROM S TO SW UPSLOPE FLOW AND LOW LEVEL WIND
CONVERGENCE CONFINED TO THE SPINE OF THE SOUTHERN APPALACHIANS THIS
AFTERNOON AND EVENING. REGIONAL RADARS ALREADY HAVE WEAK CONVECTION
ALONG THE AL/GA BORDER IN LOW LEVEL CONVERGENCE EARLY THIS
MORNING...AND ISOLD SHOWER ACTIVITY COULD REACH THE FAR SW MTNS
AROUND DAYBREAK. WRN MTN INSTABILITY WILL THEN INCREASE THROUGH THE
DAY...WITH SBCAPE VALUES RUNNING 2000 J/KG OR GREATER BY LATE
AFTERNOON NEAR THE TN BORDER. NAM AND RAP PROFILES HAVE MUCH MORE
LIMITED INSTABILITY EAST OF THE MOUNTAINS...AND THE NAM QPF
PRESENTATION OF MAINLY MTN COVERAGE FOR LATE DAY IS PREFERRED. WILL
THUS FEATURE LIKELY POPS THIS AFTN NEAR THE TN BORDER AND TAPER DOWN
TO BELOW SLIGHT CHANCE FOR CLT METRO.

CONVECTIVE COVERAGE SHOULD WANE QUICKLY THIS EVENING...BUT WILL KEEP
ISOLD SHOWER COVERAGE GOING THROUGH THE NIGHT IN DEVELOPING LIGHT
WESTERLY UPSLOPE FLOW. MILD MINS SHOULD BE ANOTHER 1 TO 2 DEGREES
WARMER THAN THIS MORNING.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 200 AM SUNDAY...UPPER HEIGHTS WILL FALL MONDAY OVER THE NERN
CONUS AS LOW PRESSURE MOVES ACRS THE GREAT LAKES. LATEST MODEL PROGS
SHOW LITTLE IMPACT IN THE HEIGHT FIELD OVER THE SOUTHEAST...BUT STILL
SHOW LLVL FLOW VEERING TO NWLY AS THE DAY PROGRESSES. WITHOUT GULF
FLOW ENHANCING WARM/MOIST ADVECTION THE THERMODYNAMIC CONDITIONS WILL
LIKELY BE SIMILAR TO SUNDAY...EXCEPT THAT THE WEAKER RIDGE WILL ALLOW
DEEP CONVECTION OVER THE PIEDMONT AS WELL AS OVER THE MTNS. DEEP
SHEAR REMAINS SMALL. SEVERE DOWNBURST WINDS CANNOT BE TOTALLY RULED
OUT BUT WILL LIKELY REMAIN ISOLATED. PWAT VALUES WELL ABOVE CLIMO AND
SHORT STORM MOTION VECTORS IMPLY HEAVY RAIN WILL BE A MORE LIKELY
THREAT.

AS THE LOW MOVES EWD INTO QUEBEC MON NIGHT...ITS COLD FRONT WILL
CROSS THE SRN APPALACHIANS. EAST OF THE MTNS CONVECTION SHOULD
GRADUALLY WANE WITH THE LOSS OF DIURNAL HEATING...BUT STRENGTHENING
UPSLOPE FLOW MAY ALLOW ACTIVITY TO CONTINUE OVERNIGHT NEAR THE TENN
BORDER. LATER ON TUE THE FRONT WILL PROGRESS ACRS THE CWFA. OVER THE
HIGHER TERRAIN SLIGHTLY COOLER TEMPS AND AN EARLIER THAN NORMAL PEAK
IN CONVECTIVE ACTIVITY ARE EXPECTED. THE PIEDMONT HOWEVER LOOKS TO
SEE A DAY VERY MUCH LIKE MONDAY...PERHAPS EVEN WITH BETTER COVERAGE
DUE TO FRONTAL CONVERGENCE OR MTN LEE TROUGHING. THE THREATS WILL BE
GENERALLY THE SAME.

MAX TEMPS MON/TUE WILL BE AROUND 5 DEG ABOVE CLIMO IN THE MTNS AND
NEAR 10 ABOVE IN THE PIEDMONT. CLOUD COVER WILL HELP KEEP MINS 7-10
DEG ABOVE CLIMO THROUGHOUT THE AREA...BUT TREND COOLER FROM TUE TO
WED MRNG AS THE CANADIAN AIRMASS SETTLES IN.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 300 AM SUNDAY...HIGH PRESSURE BUILDS INTO THE OH/TN VALLEYS WED
PUSHING THE COLD FRONT THRU OUR AREA...WHICH THEN STALLS. GFS AND EC
HAVE PREVIOUSLY DIFFERED ON WHETHER THE FRONT WOULD CLEAR THE AREA
BEFORE BECOMING STATIONARY...BUT HAVE COME CLOSER IN LINE AND SUGGEST
IT WILL DO SO NEAR OUR SRN CWFA BORDER. WITH A TROUGH PERSISTING OVER
ERN CANADA....CYCLONIC UPPER FLOW WILL BE PRESENT ALOFT OVER THE CWFA
POTENTIALLY ENHANCING ANY BAROCLINIC FORCING ASSOCIATED WITH THE
BOUNDARY. A CUTOFF UPPER LOW MOVING IN FROM THE PACIFIC WILL SPIN UP
A NEW LOW OVER THE ROCKIES SATURDAY...LIFTING THE STATIONARY FRONT
NWD AGAIN. LOW CHANCES OF PRECIP RETURN THU AND PERIODICALLY CONTINUE
THRU THE WEEKEND...WITH LOW CONFIDENCE IN LIGHT OF MODEL DIFFERENCES
IN TIMING THE UPPER FEATURES WHICH INTERACT WITH THE BOUNDARY...AND
IN THE PLACEMENT OF THE BOUNDARY ITSELF...SINCE AREAS ON ITS WARM
SIDE ARE LIKELY TO SEE SOME DIURNAL CONVECTION. TEMPS COOL SLIGHTLY
BY THU...REMAINING JUST ABOVE CLIMO FOR MINS/MAXES THRU THE END OF
THE PERIOD.

&&

.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
AT KCLT...EXPECT MAINLY CIRRUS CEILINGS THROUGH MOST OF THE
PERIOD...BUT WITH A HEALTHY CUMULUS FIELD DEVELOPING ONCE AGAIN
AROUND 5 KFT WITH DAYTIME HEATING. THE MODEL PROFILES ARE ALSO
SUGGESTING THAT A BRIEF ROUND OF LOWER STRATUS COULD DEVELOP TOWARD
DAYBREAK...BUT THIS IS LARGELY ABSENT FROM THE MOS GUIDANCE. WILL
THUS FEATURE ONLY A SCATTERED MVFR LEVEL LOWER CLOUD LAYER CIRCA 11Z
TO 13Z. WARM TEMPERATURES ALOFT UNDER THE RIDGE WILL LIMIT
INSTABILITY AND LITTLE IN THE WAY OF CONVECTIVE TRIGGERS WILL BE
FOUND EAST OF THE MTNS THIS AFTN/EVENING. EXPECT LIGHT S TO SW WINDS
THROUGHOUT AT LESS THAN 10 KT.

ELSEWHERE...MAINLY ALTOCUMULUS AND CIRRUS CEILINGS ARE EXPECTED THIS
MORNING...BUT WITH A HEALTHY CUMULUS FIELD DEVELOPING WITH HEATING
TO PRODUCE SOME VFR CIGS AT 4 TO 5 KFT THROUGH THE DAY. THE DEEPER
MOISTURE AND BEST FORCING FROM UPSLOPE AND LOW LEVEL WIND
CONVERGENCE WILL BE FOUND OVER THE WRN MTNS AND ALONG THE RIDGE TOPS
TODAY...WITH KAVL STANDING THE BEST CHANCE OF AN AFTN/EVENING TSRA.
WILL FEATURE VCSH WITH AFTN PROB30 TSRA AT KAVL...AND PROB30 TSRA AT
KHKY...BUT KEEP THE UPSTATE TAF SITES DRY WITH MORE LIMITED
INSTABILITY EXPECTED IN THE PROFILES. WINDS WILL BE LIGHT S TO SW
THROUGHOUT AT 10 KT OR LESS THROUGH THE PERIOD.

OUTLOOK...DEEPER MOISTURE WILL ARRIVE IN THE APPALACHIANS MON
THROUGH TUE AS A COLD FRONT APPROACHES FROM THE W. THE FRONT WILL
SETTLE SOUTHEAST OF THE AREA ON WEDNESDAY TO PERMIT BRIEF DRYING MID
WEEK. UNTIL THEN...DIURNAL SHOWERS AND THUNDERSTORMS WILL
FORM...WITH THE BEST COVERAGE OVER THE MTNS...WITH MORNING FOG
LIKELY IN AREAS THAT RECEIVE RAINFALL.

CONFIDENCE TABLE...

            09-15Z        15-21Z        21-03Z        03-06Z
KCLT       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAVL       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KHKY       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGMU       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAND       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...WIMBERLEY
NEAR TERM...HG
SHORT TERM...WIMBERLEY
LONG TERM...WIMBERLEY
AVIATION...HG




AREA FORECAST DISCUSSION

NWS GREENVILLE-SPARTANBURG SC

 312 AM EDT SUN MAY 17 2015

.SYNOPSIS...
BERMUDA HIGH PRESSURE WILL PERSIST OVER THE SOUTHEAST EARLY
THIS WEEK. A COLD FRONT WILL APPROACH LATE MONDAY AND MOVE THROUGH
ON TUESDAY...BRINGING PRECIPITATION CHANCES TO BOTH THE MOUNTAINS
AND PIEDMONT. SLIGHTLY COOLER AND DRIER HIGH PRESSURE WILL RETURN
WEDNESDAY. SOMEWHAT UNSETTLED WEATHER WILL RETURN LATE IN THE WEEK
WITH A STATIONARY FRONT SETTING UP OVER THE REGION.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 230 AM EDT...THE HIGHLY AMPLIFIED UPPER FLOW PATTERN OVER THE
CONUS WILL KEEP A RIDGE IN PLACE OVER THE SE THROUGH THE NEAR TERM.
PLENTY OF MID AND HIGH DEBRIS CLOUDS WILL RIDE OVER THE RIDGE AXIS
ACROSS THE AREA...BUT WITH ENOUGH BREAKS TO PERMIT MAX TEMPS TO
CLIMB TO ABOUT 5 DEGREES ABOVE CLIMO IN MOST AREAS...AND TO FOSTER A
HEALTHY CUMULUS FIELD. THE NUMERICAL MODELS KEEP THE DEEPEST
MOISTURE AND BEST FORCING FROM S TO SW UPSLOPE FLOW AND LOW LEVEL
WIND CONVERGENCE CONFINED TO THE SPINE OF THE SOUTHERN APPALACHIANS
THIS AFTERNOON AND EVENING. REGIONAL RADARS ALREADY HAVE WEAK
CONVECTION ALONG THE AL/GA BORDER IN LOW LEVEL CONVERGENCE EARLY
THIS MORNING...AND ISOLD SHOWER ACTIVITY COULD REACH THE FAR SW MTNS
AROUND DAYBREAK. WRN MTN INSTABILITY WILL THEN INCREASE THROUGH THE
DAY...WITH SBCAPE VALUES RUNNING 2000 J/KG OR GREATER BY LATE
AFTERNOON NEAR THE TN BORDER. NAM AND RAP PROFILES HAVE MUCH MORE
LIMITED INSTABILITY EAST OF THE MOUNTAINS...AND THE NAM QPF
PRESENTATION OF MAINLY MTN COVERAGE FOR LATE DAY IS PREFERRED. WILL
THUS FEATURE LIKELY POPS THIS AFTN NEAR THE TN BORDER AND TAPER DOWN
TO BELOW SLIGHT CHANCE FOR CLT METRO.

CONVECTIVE COVERAGE SHOULD WANE QUICKLY THIS EVENING...BUT WILL KEEP
ISOLD SHOWER COVERAGE GOING THROUGH THE NIGHT IN DEVELOPING LIGHT
WESTERLY UPSLOPE FLOW. MILD MINS SHOULD BE ANOTHER 1 TO 2 DEGREES
WARMER THAN THIS MORNING.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 200 AM SUNDAY...UPPER HEIGHTS WILL FALL MONDAY OVER THE NERN
CONUS AS LOW PRESSURE MOVES ACRS THE GREAT LAKES. LATEST MODEL PROGS
SHOW LITTLE IMPACT IN THE HEIGHT FIELD OVER THE SOUTHEAST...BUT STILL
SHOW LLVL FLOW VEERING TO NWLY AS THE DAY PROGRESSES. WITHOUT GULF
FLOW ENHANCING WARM/MOIST ADVECTION THE THERMODYNAMIC CONDITIONS WILL
LIKELY BE SIMILAR TO SUNDAY...EXCEPT THAT THE WEAKER RIDGE WILL ALLOW
DEEP CONVECTION OVER THE PIEDMONT AS WELL AS OVER THE MTNS. DEEP
SHEAR REMAINS SMALL. SEVERE DOWNBURST WINDS CANNOT BE TOTALLY RULED
OUT BUT WILL LIKELY REMAIN ISOLATED. PWAT VALUES WELL ABOVE CLIMO AND
SHORT STORM MOTION VECTORS IMPLY HEAVY RAIN WILL BE A MORE LIKELY
THREAT.

AS THE LOW MOVES EWD INTO QUEBEC MON NIGHT...ITS COLD FRONT WILL
CROSS THE SRN APPALACHIANS. EAST OF THE MTNS CONVECTION SHOULD
GRADUALLY WANE WITH THE LOSS OF DIURNAL HEATING...BUT STRENGTHENING
UPSLOPE FLOW MAY ALLOW ACTIVITY TO CONTINUE OVERNIGHT NEAR THE TENN
BORDER. LATER ON TUE THE FRONT WILL PROGRESS ACRS THE CWFA. OVER THE
HIGHER TERRAIN SLIGHTLY COOLER TEMPS AND AN EARLIER THAN NORMAL PEAK
IN CONVECTIVE ACTIVITY ARE EXPECTED. THE PIEDMONT HOWEVER LOOKS TO
SEE A DAY VERY MUCH LIKE MONDAY...PERHAPS EVEN WITH BETTER COVERAGE
DUE TO FRONTAL CONVERGENCE OR MTN LEE TROUGHING. THE THREATS WILL BE
GENERALLY THE SAME.

MAX TEMPS MON/TUE WILL BE AROUND 5 DEG ABOVE CLIMO IN THE MTNS AND
NEAR 10 ABOVE IN THE PIEDMONT. CLOUD COVER WILL HELP KEEP MINS 7-10
DEG ABOVE CLIMO THROUGHOUT THE AREA...BUT TREND COOLER FROM TUE TO
WED MRNG AS THE CANADIAN AIRMASS SETTLES IN.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 300 AM SUNDAY...HIGH PRESSURE BUILDS INTO THE OH/TN VALLEYS WED
PUSHING THE COLD FRONT THRU OUR AREA...WHICH THEN STALLS. GFS AND EC
HAVE PREVIOUSLY DIFFERED ON WHETHER THE FRONT WOULD CLEAR THE AREA
BEFORE BECOMING STATIONARY...BUT HAVE COME CLOSER IN LINE AND SUGGEST
IT WILL DO SO NEAR OUR SRN CWFA BORDER. WITH A TROUGH PERSISTING OVER
ERN CANADA....CYCLONIC UPPER FLOW WILL BE PRESENT ALOFT OVER THE CWFA
POTENTIALLY ENHANCING ANY BAROCLINIC FORCING ASSOCIATED WITH THE
BOUNDARY. A CUTOFF UPPER LOW MOVING IN FROM THE PACIFIC WILL SPIN UP
A NEW LOW OVER THE ROCKIES SATURDAY...LIFTING THE STATIONARY FRONT
NWD AGAIN. LOW CHANCES OF PRECIP RETURN THU AND PERIODICALLY CONTINUE
THRU THE WEEKEND...WITH LOW CONFIDENCE IN LIGHT OF MODEL DIFFERENCES
IN TIMING THE UPPER FEATURES WHICH INTERACT WITH THE BOUNDARY...AND
IN THE PLACEMENT OF THE BOUNDARY ITSELF...SINCE AREAS ON ITS WARM
SIDE ARE LIKELY TO SEE SOME DIURNAL CONVECTION. TEMPS COOL SLIGHTLY
BY THU...REMAINING JUST ABOVE CLIMO FOR MINS/MAXES THRU THE END OF
THE PERIOD.

&&

.AVIATION /07Z SUNDAY THROUGH THURSDAY/...
AT KCLT...EXPECT MAINLY CIRRUS CEILINGS THROUGH MOST OF THE
PERIOD...BUT WITH A HEALTHY CUMULUS FIELD DEVELOPING ONCE AGAIN
AROUND 5 KFT WITH DAYTIME HEATING. THE MODEL PROFILES ARE ALSO
SUGGESTING THAT A BRIEF ROUND OF LOWER STRATUS COULD DEVELOP TOWARD
DAYBREAK...BUT THIS IS LARGELY ABSENT FROM THE MOS GUIDANCE. WILL
THUS FEATURE ONLY A SCATTERED MVFR LEVEL LOWER CLOUD LAYER CIRCA 11Z
TO 13Z. WARM TEMPERATURES ALOFT UNDER THE RIDGE WILL LIMIT
INSTABILITY AND LITTLE IN THE WAY OF CONVECTIVE TRIGGERS WILL BE
FOUND EAST OF THE MTNS THIS AFTN/EVENING. EXPECT LIGHT S TO SW WINDS
THROUGHOUT AT LESS THAN 10 KT.

ELSEWHERE...MAINLY ALTOCUMULUS AND CIRRUS CEILINGS ARE EXPECTED THIS
MORNING...BUT WITH A HEALTHY CUMULUS FIELD DEVELOPING WITH HEATING
TO PRODUCE SOME VFR CIGS AT 4 TO 5 KFT THROUGH THE DAY. THE DEEPER
MOISTURE AND BEST FORCING FROM UPSLOPE AND LOW LEVEL WIND
CONVERGENCE WILL BE FOUND OVER THE WRN MTNS AND ALONG THE RIDGE TOPS
TODAY...WITH KAVL STANDING THE BEST CHANCE OF AN AFTN/EVENING TSRA.
WILL FEATURE VCSH WITH AFTN PROB30 TSRA AT KAVL...AND PROB30 TSRA AT
KHKY...BUT KEEP THE UPSTATE TAF SITES DRY WITH MORE LIMITED
INSTABILITY EXPECTED IN THE PROFILES. WINDS WILL BE LIGHT S TO SW
THROUGHOUT AT 10 KT OR LESS THROUGH THE PERIOD.

OUTLOOK...DEEPER MOISTURE WILL ARRIVE IN THE APPALACHIANS MON
THROUGH TUE AS A COLD FRONT APPROACHES FROM THE W. THE FRONT WILL
SETTLE SOUTHEAST OF THE AREA ON WEDNESDAY TO PERMIT BRIEF DRYING MID
WEEK. UNTIL THEN...DIURNAL SHOWERS AND THUNDERSTORMS WILL
FORM...WITH THE BEST COVERAGE OVER THE MTNS...WITH MORNING FOG
LIKELY IN AREAS THAT RECEIVE RAINFALL.

CONFIDENCE TABLE...

            07-13Z        13-19Z        19-01Z        01-06Z
KCLT       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAVL       HIGH 100%     HIGH 100%     HIGH  98%     HIGH 100%
KHKY       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGMU       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAND       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...WIMBERLEY
NEAR TERM...HG
SHORT TERM...WIMBERLEY
LONG TERM...WIMBERLEY
AVIATION...HG




AREA FORECAST DISCUSSION

NWS GREENVILLE-SPARTANBURG SC

 152 AM EDT SUN MAY 17 2015

.SYNOPSIS...
BERMUDA HIGH PRESSURE WILL REMAIN OVER THE REGION THROUGH THE
WEEKEND AND EARLY NEXT WEEK. INCREASING MOISTURE OVER THE WESTERN
EDGE OF THE HIGH WILL BRING PRECIPITATION CHANCES MAINLY TO THE
MOUNTAINS EACH DAY. A COLD FRONT WILL APPROACH THE WESTERN CAROLINAS
LATE MONDAY AND MOVE OVER THE AREA ON TUESDAY. SLIGHTLY COOLER AND
DRIER HIGH PRESSURE WILL RETURN WEDNESDAY IN THE WAKE OF THE FRONT
AND LINGER THROUGH AT LEAST THURSDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 135 AM EDT...THE HIGHLY AMPLIFIED UPPER FLOW PATTERN OVER THE
CONUS WILL KEEP A RIDGE IN PLACE OVER THE SE THROUGH THE NEAR TERM.
PLENTY OF MID AND HIGH DEBRIS CLOUDS WILL RIDE OVER THE RIDGE AXIS
ACROSS THE AREA...BUT WITH ENOUGH BREAKS TO PERMIT MAX TEMPS TO
CLIMB TO ABOUT 5 DEGREES ABOVE CLIMO IN MOST AREAS...AND TO FOSTER A
HEALTHY CUMULUS FIELD. THE NUMERICAL MODELS KEEP THE DEEPEST
MOISTURE AND BEST FORCING FROM S TO SW UPSLOPE FLOW AND LOW LEVEL
WIND CONVERGENCE CONFINED TO THE SPINE OF THE SOUTHERN APPALACHIANS
THIS AFTERNOON AND EVENING. REGIONAL RADARS ALREADY HAVE WEAK
CONVECTION ALONG THE AL/GA BORDER IN LOW LEVEL CONVERGENCE EARLY
THIS MORNING...AND ISOLD SHOWER ACTIVITY COULD REACH THE FAR SW MTNS
AROUND DAYBREAK. WRN MTN INSTABILITY WILL THEN INCREASE THROUGH THE
DAY...WITH SBCAPE VALUES RUNNING 2000 J/KG OR GREATER BY LATE
AFTERNOON NEAR THE TN BORDER. NAM AND RAP PROFILES HAVE MUCH MORE
LIMITED INSTABILITY EAST OF THE MOUNTAINS...AND THE NAM QPF
PRESENTATION OF MAINLY MTN COVERAGE FOR LATE DAY IS PREFERRED. WILL
THUS FEATURE LIKELY POPS THIS AFTN NEAR THE TN BORDER AND TAPER DOWN
TO BELOW SLIGHT CHANCE FOR CLT METRO.

CONVECTIVE COVERAGE SHOULD WANE QUICKLY THIS EVENING...BUT WILL KEEP
ISOLD SHOWER COVERAGE GOING THROUGH THE NIGHT IN DEVELOPING LIGHT
WESTERLY UPSLOPE FLOW. MILD MINS SHOULD BE ANOTHER 1 TO 2 DEGREES
WARMER THAN THIS MORNING.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...
AS OF 245 PM SAT...WE WILL LET THE EARLIER CONVECTION WANE THROUGH
THE EVENING AND INTO THE OVERNIGHT HOURS ACROSS THE NORTH CAROLINA
MOUNTAINS AND NORTHEAST GEORGIA...WITH LOSS OF HEATING AND ABSENCE
OF CONTINUED FORCING. SUBTLE UPSLOPE WEST COMPONENT MAY KEEP THOSE
WESTERN FACING SLOPES WITH THE LAST VESTIGAGES OF SHOWERS.

THE PERSISTENT UPPER LEVEL RIDGE (H5) WILL FLATTEN SOMEWHAT MONDAY
AND EDGE OFF TO THE EAST...WHILE SURFACE LEE TROFFING (OR HYBRID
LOOK OF A BACK DOOR COLD FRONT) SETTLES ACROSS THE WESTERN/CENTRAL
NORTH CAROLINA PIEDMONT. CAPE VALUES AND PRECIPITABLE WATER INDICES
ON THE RISE MONDAY...AS A RESULT MECHANICAL LIFTING IN THE MOUNTAINS
SHOULD HELP GENERATE POPS NEAR OR SLIGHTLY ABOVE GUIDE (IN THE
LIKELY CATEGORY). WHETHER THE AFOREMENTIONED SURFACE REFLECTION
CONTRIBUTES TO ANOTHER POP FOCUS IN OUR EASTERN FORECAST AREA (FA)
MONDAY AFTERNOON IS DEBATABLE...NEVERTHELESS THE ENTIRE REGION WILL
GRADUALLY BECOMING PRIMED FOR SCATTERED CONVECTION. CORFIDI VECTORS
ARE VERY MINIMAL THEREFORE LOCALLY HEAVY RAIN IS CERTAINLY SOMETHING
IN THE CARDS. TEMPERATURE GUIDE FROM NEARLY ALL SUITE OF MODELS...
AND H85 TEMPERATURE PROFILES...ALL SUGGEST KEEPING THE CURRENT VERY
WARM TEMPERATURES IN THE FORECAST.

WE WILL SLOWLY RAMP DOWN POPS MONDAY NIGHT...ALBEIT PROBABLY MORE
SLOWLY THAN THE FASTER GUIDE POP TRENDS. A JUICY AIRMASS...WEAK
PERTABATIONS IN THE UPPER LEVELS...AND SURFACE SIGNAL...ALL COMBINE
TO SUGGEST CAUTION.

HOW TUESDAY UNFOLDS COULD BE INTERESTING...THE COLD FRONT WHICH WILL
BE APPROACHING FROM THE WEST...CONTINUES TO SLOW...WHILE THE HYBRID
TYPE WIND SHIFT SETTLES EAST AND SOUTH. THE UPPER FLOW FLATTENS...
AND THEIR APPEARS TO BE A WAVE RACING TOWARD THE REGION DURING THE
DAY. SINCE THE FLOW WILL BECOME MORE WESTERLY TUESDAY...CONVERGENCE
MIGHT BE MINIMAL...ALTHOUGH CAPE AND INSTABILITY WILL BE POSTIVES
FOR THUNDERSTORMS. AT THE MOMENT WE PLAN ON RUNNING MEDIUM RANGE
POPS...AS I CAN SEE A COUPLE OF DIFFERENT SCENERIOS WHICH WOULD
FAVOR DIFFERENT PARTS OF THE CWA. WE HAVE KEPT THE TEMPERATURES ON
THE WARM SIDE OF GUIDE TUESDAY AS WELL...GIVEN OVERALL THERMAL
PROFILE.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 2 PM EDT SATURDAY...THE MEDIUM RANGE FCST BEGINS AT 00Z ON
WEDNESDAY WITH A SOMEWHAT FLAT UPPER RIDGE OVER THE SE CONUS AND A
POTENT LOOKING UPPER SHORTWAVE/TROF MOVING OVER THE GREAT LAKES. AS
THE TROF MOVES EASTWARD AND TOWARDS NORTHERN NEW ENGLAND...THE RIDGE
REMAINS FAIRLY FLAT OVER THE SE REGION THRU THURS. THIS MOSTLY ZONAL
UPPER PATTERN IS EXPECTED TO PERSIST OVER OUR REGION THRU THE
REMAINDER OF THE PERIOD WITH A LONGWAVE UPPER TROF DIGGING DOWN OVER
EXTREME SE CANADA AND THEN NEW ENGLAND BY THE END OF PERIOD. AT THE
SFC...THE COLD FRONT THAT WAS EXPECTED TO MOVE OVER THE FCST AREA
EARLY TUES HAS BEEN TRENDING SLOWER OVER THE PAST FEW MODEL CYCLES.
NOW ITS LOOKING LIKE THE FRONT WILL MOVE THRU ABOUT 12 TO 18 HOURS
LATER ON TUES AND INTO EARLY WED. REGARDLESS...THE FRONT IS STILL
EXPECTED TO SE OF THE CWFA BY ROUGHLY 12Z ON WED WITH COOLER AND
DRIER CANADIAN HIGH PRESSURE IN ITS WAKE. THE HIGH IS EXPECTED TO
PERSIST OVER THE AREA INTO THURS WITH THE LOW LVL FLOW BECOMING MORE
WEAK VARIABLE ON FRI AND SAT. AS FOR THE SENSIBLE FCST...PRECIP
CHANCES TAPER OFF QUICKLY EARLY WED MORNING WITH VALUES LESS THAN
20% AFTER ABOUT 6Z. THE REST OF WED SHOULD BE DRY WITH THE REST OF
THE MEDIUM RANGE CHARACTERIZED BY DIURNALLY DRIVEN SLIGHT TO SOLID
CHANCES FOR SH AND TS EACH AFTERNOON/EVENING. AS IS TYPICAL WITH
SUMMERTIME CONVECTION AND ANY UPSLOPE WIND COMPONENT...THE BEST POPS
ARE EXPECTED OVER THE HIGHER TERRAIN. TEMPS WERE NOT CHANGED MUCH
FROM THE PREVIOUS FCST WITH TEMPS WELL ABOVE CLIMO EACH DAY.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AT KCLT...EXPECT MAINLY CIRRUS CEILINGS THROUGH MOST OF THE
PERIOD...BUT WITH A HEALTHY CUMULUS FIELD DEVELOPING ONCE AGAIN
AROUND 5 KFT WITH DAYTIME HEATING. THE MODEL PROFILES ARE ALSO
SUGGESTING THAT A BRIEF ROUND OF LOWER STRATUS COULD DEVELOP TOWARD
DAYBREAK...BUT THIS IS LARGELY ABSENT FROM THE MOS GUIDANCE. WILL
THUS FEATURE ONLY A SCATTERED LOWER CLOUD LAYER CIRCA 11Z TO 13Z.
WARM TEMPERATURES ALOFT UNDER THE RIDGE WILL LIMIT INSTABILITY AND
LITTLE IN THE WAY OF CONVECTIVE TRIGGERS WILL BE FOUND EAST OF THE
MTNS THIS AFTN/EVENING. EXPECT LIGHT S TO SW WINDS THROUGHOUT AT
LESS THAN 10 KT.

ELSEWHERE...MAINLY ALTOCUMULUS AND CIRRUS CEILINGS ARE EXPECTED THIS
MORNING...BUT WITH A HEALTHY CUMULUS FIELD DEVELOPING WITH HEATING
TO PRODUCE SOME VFR CIGS AT 4 TO 5 KFT THROUGH THE DAY. THE DEEPER
MOISTURE AND BEST FORCING FROM UPSLOPE AND LOW LEVEL WIND
CONVERGENCE WILL BE FOUND OVER THE WRN MTNS AND ALONG THE RIDGE TOPS
TODAY...WITH KAVL STANDING THE BEST CHANCE OF AN AFTN/EVENING TSRA.
WILL FEATURE VCSH WITH PROB30 TSRA AT KAVL...AND PROB30 TSRA AT
KHKY...BUT KEEP THE UPSTATE TAF SITES DRY WITH MORE LIMITED
INSTABILITY EXPECTED IN THE PROFILES. WINDS WILL BE LIGHT S TO SW
THROUGHOUT AT 10 KT OR LESS THROUGH THE PERIOD.

OUTLOOK...DEEPER MOISTURE WILL ARRIVE IN THE APPALACHIANS MON
THROUGH TUE AS A COLD FRONT APPROACHES FROM THE W. THE FRONT WILL
SETTLE SOUTHEAST OF THE AREA ON WEDNESDAY TO PERMIT BRIEF DRYING MID
WEEK. UNTIL THEN...DIURNAL SHOWERS AND THUNDERSTORMS WILL
FORM...WITH THE BEST COVERAGE OVER THE MTNS...WITH MORNING FOG
LIKELY IN AREAS THAT RECEIVE RAINFALL.

CONFIDENCE TABLE...

            06-12Z        12-18Z        18-24Z        00-06Z
KCLT       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAVL       HIGH 100%     HIGH 100%     HIGH  99%     HIGH 100%
KHKY       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGMU       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAND       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...JPT
NEAR TERM...HG
SHORT TERM...TS
LONG TERM...JPT
AVIATION...HG



AREA FORECAST DISCUSSION

NWS SIOUX FALLS SD

 1239 PM CDT SUN MAY 17 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 350 AM CDT SUN MAY 17 2015

UPPER LOW CENTER CURRENTLY LIFTING NORTH NORTHEAST ACROSS NORTH
CENTRAL NEBRASKA WILL SLOWLY TRACK THROUGH THE FORECAST AREA TODAY.
TWO AREAS OF RAIN SHOWERS WITH EMBEDDED THUNDER ARE IMPACTING THE
AREA. THE FIRST BROAD BAND AHEAD OF THE LOW IS TRACKING NORTHWARD
ACROSS OUR EASTERN COUNTIES AHEAD OF THE SURFACE AND UPPER LOW. THE
SECOND AREA OF PRECIPITATION ON THE BACK SIDE OF THE LOW ACROSS
SOUTH CENTRAL INTO EAST CENTRAL SOUTH DAKOTA IS PIVOTING IN A
GENERAL NORTHERLY DIRECTION IN ASSOCIATION WITH MID LEVEL TROWALING.
PRECIPITATION IS EXPECTED TO PERSIST THROUGH THE MORNING ACROSS
THESE AREAS...WITH DRY SLOTTING LIMITING PRECIPITATION TO MORE
SCATTERED ACTIVITY NEAR THE I29 CORRIDOR. THE HRRR AND RUC HAVE A
DECENT HANDLE IN THE TRACK AND TIMING OF PRECIPITATION...SO FOLLOWED
THESE MODELS. AS THE LOW BEGINS PULLING AWAY TO THE NORTH THIS
AFTERNOON...MUCH OF REGION WILL BE IN THE DRY SLOT...WITH ONLY
SCATTERED SHOWERS DIMINISHING FROM SOUTH TO NORTH THROUGH EARLY
EVENING. SEVERE STORMS ARE NOT EXPECTED WITH ACTIVITY TODAY.

CLOUDY SKIES...RAINFALL... AND COOLER AIR WRAPPING BEHIND THE LOW
WILL KEEP TEMPERATURES IN CHECK THIS AFTERNOON. THE MID TO UPPER 60S
ARE EXPECTED WEST OF I29 WITH THE LOW TO MID 70S TO THE EAST WHERE
THE COOLER AIRMASS WILL BE DELAYED AND A BIT MORE SUNSHINE AND DRIER
WEATHER IS EXPECTED. WINDS WILL INCREASE THROUGH THE DAY AS THE
PRESSURE GRADIENT TIGHTENS AS THE LOW LIFTS NORTH OF THE AREA.
SUSTAINED WINDS WILL BE NEAR ADVISORY LEVEL MID TO LATE
AFTERNOON...BUT RIGHT NOW IT LOOKS LIKE THEY WILL REMAIN TOO LOW FOR
HEADLINES. SKIES WILL REMAIN PARTLY TO MOSTLY CLOUDY TONIGHT WITH
MUCH COLDER TEMPERATURES FILTERING INTO THE REGION. LOWS TONIGHT
WILL BE IN THE MID 30S TO MID 40S.

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 350 AM CDT SUN MAY 17 2015

WINDY AND COOL STILL LOOKS GOOD FOR MONDAY. THE UPPER LOW WILL BE
FAR ENOUGH NORTHEAST TO PROVIDE LITTLE OR NO DYNAMIC SUPPORT FOR
LIGHT SHOWERS...AND WHILE THERE COULD BE A FEW SPRINKLES WITH THE
LOW CLOUDS...WILL LEAVE OUT FOR NOW. THE LOW CLOUD COVER SHOULD
DOMINATE SKIES OVER THE NORTHEAST TO EAST CENTRAL PART OF THE
FORECAST AREA WITH LESSER CLOUD COVER TO THE SOUTHWEST. TEMPERATURES
WILL BE ON THE VERY CHILLY SIDE WITH HIGHS IN THE MID 40S NORTHEAST
TO THE MID 50S SOUTH.

CLEARING SKIES MONDAY NIGHT WITH HIGH PRESSURE RIDGING INTO THE AREA
AND THIS HIGH WILL ALSO BRING DECREASING WINDS. CHILLY TEMPERATURES
MAY DROP TO FROSTY OR FREEZY LEVELS AND WIND LOOK LIGHT ENOUGH BY
EARLY TUESDAY MORNING TO ALLOW FOR FROST EXCEPT IN PART OF SOUTHWEST
MINNESOTA SO AFTER COORDINATION WILL SO MENTION.

TUESDAY LOOKS FAIRLY SUNNY WITH SOME SLOW INCREASE IN CLOUDS
SOUTHWEST. THIS SLOW CLOUD INCREASE WILL CONTINUE FROM THE SOUTHWEST
TUESDAY NIGHT INTO WEDNESDAY AS AN EJECTED WAVE FROM PACIFIC COAST
TROUGH APPROACHES FROM THE SOUTHWEST. THIS WAVE WILL BE SUPPRESSED
TO SOME DEGREE BY A NORTHWESTERLY UPPER FLOW OVER THE WESTERN GREAT
LAKES. LIGHT RAIN LIKELY SPREADING INTO THE SOUTHWEST CORNER OF THE
AREA LATE TUESDAY NIGHT MAY NOT GET TOO FAR NORTHEAST IF THIS
SUPPRESSION IS STRONG ENOUGH. FOR NOW WILL KEEP SOME MENTION OF
LIGHT RAIN CHANCE WEDNESDAY OVER THE SOUTHWEST HALF OF THE AREA. DO
NOT EXPECT MUCH RAIN IN ANY EVENT AS THE SYSTEM WILL BE STEADILY
WEAKENING WHILE BEING SUPPRESSED BETWEEN THE NORTHWESTERLY FLOW AND A
MODEST SOUTHERN PLAINS RIDGE. TEMPERATURES WILL STILL BE COOL WITH
50S HIGHS TUESDAY AND WEDNESDAY.

THE DEPARTURE OF WHAT IS LEFT OF THE WEAK WAVE WILL ALLOW THE RIDGE
TO BUILD A LITTLE MORE INTO THE AREA AND BRING DRY WEATHER WITH
MODEST WARMING THURSDAY INTO FRIDAY. LATE FRIDAY AND SATURDAY WILL
BRING A CHANCE OF SHOWERS AND STORMS AS THE PACIFIC TROUGH
APPROACHES.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1237 PM CDT SUN MAY 17 2015

COMPLEX SET UP THIS AFTERNOON. VFR EAST OF INTERSTATE 29 BUT
SCATTERED THUNDERSTORMS CAN BE EXPECTED THROUGH LATE AFTERNOON.
ALONG AND EAST OF INTERSTATE 29 MVFR CEILINGS...POSSIBLY SHORT
LIVED IFR CEILINGS...ALONG WITH STRATIFORM RAINFALL. THE BULK OF
THIS PRECIPITATION WILL LIFT NORTHEAST WITH ONLY LIGHTER AMOUINTS
EXPECTED ACROSS MOST OF THE CWA. MVFR CEILINGS LIKELY OFF AND ON
THROUGH THE ENTIRE PERIOD. WINDS WILL ALSO BE A PROBLEM WITH
NORTHWEST WINDS GUSTING TO ABOUT 45 MPH AT TIMES...MAINLY BEFORE
6Z.

&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...WIND ADVISORY FROM 4 PM THIS AFTERNOON TO 4 AM CDT MONDAY FOR
     SDZ040-054>056-060>062-065>067.

     WIND ADVISORY UNTIL 1 AM CDT MONDAY FOR SDZ038-039-052-053-
     057>059-063-064.

MN...WIND ADVISORY FROM 4 PM THIS AFTERNOON TO 4 AM CDT MONDAY FOR
     MNZ071-072-080-081-089-090-097-098.

IA...NONE.
NE...NONE.
&&

$$

SHORT TERM...
LONG TERM...
AVIATION...08



AREA FORECAST DISCUSSION

NWS SIOUX FALLS SD

 633 AM CDT SUN MAY 17 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 350 AM CDT SUN MAY 17 2015

UPPER LOW CENTER CURRENTLY LIFTING NORTH NORTHEAST ACROSS NORTH
CENTRAL NEBRASKA WILL SLOWLY TRACK THROUGH THE FORECAST AREA TODAY.
TWO AREAS OF RAIN SHOWERS WITH EMBEDDED THUNDER ARE IMPACTING THE
AREA. THE FIRST BROAD BAND AHEAD OF THE LOW IS TRACKING NORTHWARD
ACROSS OUR EASTERN COUNTIES AHEAD OF THE SURFACE AND UPPER LOW. THE
SECOND AREA OF PRECIPITATION ON THE BACK SIDE OF THE LOW ACROSS
SOUTH CENTRAL INTO EAST CENTRAL SOUTH DAKOTA IS PIVOTING IN A
GENERAL NORTHERLY DIRECTION IN ASSOCIATION WITH MID LEVEL TROWALING.
PRECIPITATION IS EXPECTED TO PERSIST THROUGH THE MORNING ACROSS
THESE AREAS...WITH DRY SLOTTING LIMITING PRECIPITATION TO MORE
SCATTERED ACTIVITY NEAR THE I29 CORRIDOR. THE HRRR AND RUC HAVE A
DECENT HANDLE IN THE TRACK AND TIMING OF PRECIPITATION...SO FOLLOWED
THESE MODELS. AS THE LOW BEGINS PULLING AWAY TO THE NORTH THIS
AFTERNOON...MUCH OF REGION WILL BE IN THE DRY SLOT...WITH ONLY
SCATTERED SHOWERS DIMINISHING FROM SOUTH TO NORTH THROUGH EARLY
EVENING. SEVERE STORMS ARE NOT EXPECTED WITH ACTIVITY TODAY.

CLOUDY SKIES...RAINFALL... AND COOLER AIR WRAPPING BEHIND THE LOW
WILL KEEP TEMPERATURES IN CHECK THIS AFTERNOON. THE MID TO UPPER 60S
ARE EXPECTED WEST OF I29 WITH THE LOW TO MID 70S TO THE EAST WHERE
THE COOLER AIRMASS WILL BE DELAYED AND A BIT MORE SUNSHINE AND DRIER
WEATHER IS EXPECTED. WINDS WILL INCREASE THROUGH THE DAY AS THE
PRESSURE GRADIENT TIGHTENS AS THE LOW LIFTS NORTH OF THE AREA.
SUSTAINED WINDS WILL BE NEAR ADVISORY LEVEL MID TO LATE
AFTERNOON...BUT RIGHT NOW IT LOOKS LIKE THEY WILL REMAIN TOO LOW FOR
HEADLINES. SKIES WILL REMAIN PARTLY TO MOSTLY CLOUDY TONIGHT WITH
MUCH COLDER TEMPERATURES FILTERING INTO THE REGION. LOWS TONIGHT
WILL BE IN THE MID 30S TO MID 40S.

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 350 AM CDT SUN MAY 17 2015

WINDY AND COOL STILL LOOKS GOOD FOR MONDAY. THE UPPER LOW WILL BE
FAR ENOUGH NORTHEAST TO PROVIDE LITTLE OR NO DYNAMIC SUPPORT FOR
LIGHT SHOWERS...AND WHILE THERE COULD BE A FEW SPRINKLES WITH THE
LOW CLOUDS...WILL LEAVE OUT FOR NOW. THE LOW CLOUD COVER SHOULD
DOMINATE SKIES OVER THE NORTHEAST TO EAST CENTRAL PART OF THE
FORECAST AREA WITH LESSER CLOUD COVER TO THE SOUTHWEST. TEMPERATURES
WILL BE ON THE VERY CHILLY SIDE WITH HIGHS IN THE MID 40S NORTHEAST
TO THE MID 50S SOUTH.

CLEARING SKIES MONDAY NIGHT WITH HIGH PRESSURE RIDGING INTO THE AREA
AND THIS HIGH WILL ALSO BRING DECREASING WINDS. CHILLY TEMPERATURES
MAY DROP TO FROSTY OR FREEZY LEVELS AND WIND LOOK LIGHT ENOUGH BY
EARLY TUESDAY MORNING TO ALLOW FOR FROST EXCEPT IN PART OF SOUTHWEST
MINNESOTA SO AFTER COORDINATION WILL SO MENTION.

TUESDAY LOOKS FAIRLY SUNNY WITH SOME SLOW INCREASE IN CLOUDS
SOUTHWEST. THIS SLOW CLOUD INCREASE WILL CONTINUE FROM THE SOUTHWEST
TUESDAY NIGHT INTO WEDNESDAY AS AN EJECTED WAVE FROM PACIFIC COAST
TROUGH APPROACHES FROM THE SOUTHWEST. THIS WAVE WILL BE SUPPRESSED
TO SOME DEGREE BY A NORTHWESTERLY UPPER FLOW OVER THE WESTERN GREAT
LAKES. LIGHT RAIN LIKELY SPREADING INTO THE SOUTHWEST CORNER OF THE
AREA LATE TUESDAY NIGHT MAY NOT GET TOO FAR NORTHEAST IF THIS
SUPPRESSION IS STRONG ENOUGH. FOR NOW WILL KEEP SOME MENTION OF
LIGHT RAIN CHANCE WEDNESDAY OVER THE SOUTHWEST HALF OF THE AREA. DO
NOT EXPECT MUCH RAIN IN ANY EVENT AS THE SYSTEM WILL BE STEADILY
WEAKENING WHILE BEING SUPPRESSED BETWEEN THE NORTHWESTERLY FLOW AND A
MODEST SOUTHERN PLAINS RIDGE. TEMPERATURES WILL STILL BE COOL WITH
50S HIGHS TUESDAY AND WEDNESDAY.

THE DEPARTURE OF WHAT IS LEFT OF THE WEAK WAVE WILL ALLOW THE RIDGE
TO BUILD A LITTLE MORE INTO THE AREA AND BRING DRY WEATHER WITH
MODEST WARMING THURSDAY INTO FRIDAY. LATE FRIDAY AND SATURDAY WILL
BRING A CHANCE OF SHOWERS AND STORMS AS THE PACIFIC TROUGH
APPROACHES.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 626 AM CDT SUN MAY 17 2015

SHOWERS WITH EMBEDDED THUNDERSTORMS WILL CONTINUE TO TRACK
NORTHWARD ACROSS THE REGION THIS MORNING...THEN DIMINISH SOUTH TO
NORTH THIS AFTERNOON. MVFR CEILINGS AND VISIBILITY WILL BE
ASSOCIATED WITH RAIN SHOWERS. THE QUESTION IS HOW LONG THE MVFR
CONDITIONS LINGER...AS MODELS VARY WITH CEILING HEIGHTS THIS
AFTERNOON THROUGH TONIGHT. FOR NOW...WILL BRING IN SOME IMPROVE
TO LOW END VFR LATE MORNING AND AFTERNOON AND THEN DROP BACK TO
MVFR THIS EVENING AND TONIGHT AT KFSD AND KHON. KSUX IS LESS
CERTAIN...SO LEFT VFR THERE OVERNIGHT.

&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&

$$

SHORT TERM...
LONG TERM...
AVIATION...




AREA FORECAST DISCUSSION

NWS SIOUX FALLS SD

 350 AM CDT SUN MAY 17 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 350 AM CDT SUN MAY 17 2015

UPPER LOW CENTER CURRENTLY LIFTING NORTH NORTHEAST ACROSS NORTH
CENTRAL NEBRASKA WILL SLOWLY TRACK THROUGH THE FORECAST AREA TODAY.
TWO AREAS OF RAIN SHOWERS WITH EMBEDDED THUNDER ARE IMPACTING THE
AREA. THE FIRST BROAD BAND AHEAD OF THE LOW IS TRACKING NORTHWARD
ACROSS OUR EASTERN COUNTIES AHEAD OF THE SURFACE AND UPPER LOW. THE
SECOND AREA OF PRECIPITATION ON THE BACK SIDE OF THE LOW ACROSS
SOUTH CENTRAL INTO EAST CENTRAL SOUTH DAKOTA IS PIVOTING IN A
GENERAL NORTHERLY DIRECTION IN ASSOCIATION WITH MID LEVEL TROWALING.
PRECIPITATION IS EXPECTED TO PERSIST THROUGH THE MORNING ACROSS
THESE AREAS...WITH DRY SLOTTING LIMITING PRECIPITATION TO MORE
SCATTERED ACTIVITY NEAR THE I29 CORRIDOR. THE HRRR AND RUC HAVE A
DECENT HANDLE IN THE TRACK AND TIMING OF PRECIPITATION...SO FOLLOWED
THESE MODELS. AS THE LOW BEGINS PULLING AWAY TO THE NORTH THIS
AFTERNOON...MUCH OF REGION WILL BE IN THE DRY SLOT...WITH ONLY
SCATTERED SHOWERS DIMINISHING FROM SOUTH TO NORTH THROUGH EARLY
EVENING. SEVERE STORMS ARE NOT EXPECTED WITH ACTIVITY TODAY.

CLOUDY SKIES...RAINFALL... AND COOLER AIR WRAPPING BEHIND THE LOW
WILL KEEP TEMPERATURES IN CHECK THIS AFTERNOON. THE MID TO UPPER 60S
ARE EXPECTED WEST OF I29 WITH THE LOW TO MID 70S TO THE EAST WHERE
THE COOLER AIRMASS WILL BE DELAYED AND A BIT MORE SUNSHINE AND DRIER
WEATHER IS EXPECTED. WINDS WILL INCREASE THROUGH THE DAY AS THE
PRESSURE GRADIENT TIGHTENS AS THE LOW LIFTS NORTH OF THE AREA.
SUSTAINED WINDS WILL BE NEAR ADVISORY LEVEL MID TO LATE
AFTERNOON...BUT RIGHT NOW IT LOOKS LIKE THEY WILL REMAIN TOO LOW FOR
HEADLINES. SKIES WILL REMAIN PARTLY TO MOSTLY CLOUDY TONIGHT WITH
MUCH COLDER TEMPERATURES FILTERING INTO THE REGION. LOWS TONIGHT
WILL BE IN THE MID 30S TO MID 40S.


.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 350 AM CDT SUN MAY 17 2015

WINDY AND COOL STILL LOOKS GOOD FOR MONDAY. THE UPPER LOW WILL BE
FAR ENOUGH NORTHEAST TO PROVIDE LITTLE OR NO DYNAMIC SUPPORT FOR
LIGHT SHOWERS...AND WHILE THERE COULD BE A FEW SPRINKLES WITH THE
LOW CLOUDS...WILL LEAVE OUT FOR NOW. THE LOW CLOUD COVER SHOULD
DOMINATE SKIES OVER THE NORTHEAST TO EAST CENTRAL PART OF THE
FORECAST AREA WITH LESSER CLOUD COVER TO THE SOUTHWEST. TEMPERATURES
WILL BE ON THE VERY CHILLY SIDE WITH HIGHS IN THE MID 40S NORTHEAST
TO THE MID 50S SOUTH.

CLEARING SKIES MONDAY NIGHT WITH HIGH PRESSURE RIDGING INTO THE AREA
AND THIS HIGH WILL ALSO BRING DECREASING WINDS. CHILLY TEMPERATURES
MAY DROP TO FROSTY OR FREEZY LEVELS AND WIND LOOK LIGHT ENOUGH BY
EARLY TUESDAY MORNING TO ALLOW FOR FROST EXCEPT IN PART OF SOUTHWEST
MINNESOTA SO AFTER COORDINATION WILL SO MENTION.

TUESDAY LOOKS FAIRLY SUNNY WITH SOME SLOW INCREASE IN CLOUDS
SOUTHWEST. THIS SLOW CLOUD INCREASE WILL CONTINUE FROM THE SOUTHWEST
TUESDAY NIGHT INTO WEDNESDAY AS AN EJECTED WAVE FROM PACIFIC COAST
TROUGH APPROACHES FROM THE SOUTHWEST. THIS WAVE WILL BE SUPPRESSED
TO SOME DEGREE BY A NORTHWESTERLY UPPER FLOW OVER THE WESTERN GREAT
LAKES. LIGHT RAIN LIKELY SPREADING INTO THE SOUTHWEST CORNER OF THE
AREA LATE TUESDAY NIGHT MAY NOT GET TOO FAR NORTHEAST IF THIS
SUPPRESSION IS STRONG ENOUGH. FOR NOW WILL KEEP SOME MENTION OF
LIGHT RAIN CHANCE WEDNESDAY OVER THE SOUTHWEST HALF OF THE AREA. DO
NOT EXPECT MUCH RAIN IN ANY EVENT AS THE SYSTEM WILL BE STEADILY
WEAKENING WHILE BEING SUPPRESSED BETWEEN THE NORTHWESTERLY FLOW AND A
MODEST SOUTHERN PLAINS RIDGE. TEMPERATURES WILL STILL BE COOL WITH
50S HIGHS TUESDAY AND WEDNESDAY.

THE DEPARTURE OF WHAT IS LEFT OF THE WEAK WAVE WILL ALLOW THE RIDGE
TO BUILD A LITTLE MORE INTO THE AREA AND BRING DRY WEATHER WITH
MODEST WARMING THURSDAY INTO FRIDAY. LATE FRIDAY AND SATURDAY WILL
BRING A CHANCE OF SHOWERS AND STORMS AS THE PACIFIC TROUGH
APPROACHES.


&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1051 PM CDT SAT MAY 16 2015

THE LATEST HRRR AND NAM12 MODELS CONTINUE TO BE IN PRETTY GOOD
AGREEMENT IN BRINGING THE NEXT ROUND OF RAINFALL NORTHWARD LATE
TONIGHT...THEN CURLING THE PRECIPITATION WESTWARD TOWARD DAY BREAK
SUNDAY. THERE IS A LOT OF RAINFALL UPSTREAM IN EASTERN NEB AND
WESTERN KS...SO HAVE NO REASON TO DOUBT THIS SCENARIO YET SO
INCLUDED THE RAIN IN THE TAFS. THE BIGGEST QUESTION MARK IS THE
AMOUNT OF THUNDERSTORMS. THERE COULD BE ELEVATED STORMS EMBEDDED
IN THE RAIN...SO INCLUDED THE MENTION OF TSRA ONLY IN A TEMPO
GROUP FOR OUR THREE SITES. FURTHERMORE...THE HUMIDITY TIME
SECTIONS AND MODEL SOUNDINGS SHOW WIDESPREAD MVFR TO POSSIBLE
LOWER END IFR CONDITIONS TAKING OVER LATE TONIGHT AND SUNDAY
MORNING NORTH OF I 90 IMPACTING THE KHON TAF SITE. HEADING FURTHER
SOUTHWARD...THE CEILINGS WILL BE HIGHER WITH LESS RAINFALL ON
SUNDAY. THEREFORE AM LESS PESSIMISTIC WITH THE CEILINGS IN THE
KFSD AND KSUX TAF SITES.


&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&

$$

SHORT TERM...
LONG TERM...
AVIATION...MJ



AREA FORECAST DISCUSSION

NWS NASHVILLE TN

 844 PM CDT MON MAY 18 2015

.DISCUSSION...
FRONTAL BOUNDARY CURRENTLY STRETCHES FROM CENTRAL IN SOUTHWEST
THROUGH THE MO BOOTHEEL. THIS FEATURE WILL MOVE SOUTHEAST AND
PUSH ACROSS THE MID STATE LATE TONIGHT. FORCING ALONG THIS
BOUNDARY IS EXPECTED TO BE VERY WEAK. IN FACT...NVA LOOKS LIKE IT
WILL DOMINATE AFT 06Z. LATEST HRRR SHOWS A NARROW AND VERY LIGHT
DISORGANIZED BAND OF SHOWER ACTIVITY FOR LATE TONIGHT WHEN THE
FRONT MOVES THROUGH.

WILL GO AHEAD AND LOWER POPS. I WILL KEEP THE CHC CATEGORY GOING
OVER THE FAR SOUTHEAST FOR THE PRE 06Z TIMEFRAME. AFT 06Z...WILL
KEEP A SLIGHT CHANCE OF SHOWERS AND TSTMS GOING AREA WIDE.

OTW...WILL GO AHEAD AND ADD SOME PATCHY FOG ACROSS THE PLATEAU FOR
LATE TONIGHT. MODEL GUIDANCE LEANS TOWARD THE REDUCTION OF VSBYS. ALSO...
DRIER AIR IS NOT EXPECTED TO REACH THE PLAT PRIOR TO 12Z.
REMAINDER OF FCST APPEARS TO BE ON TRACK. COOLER AIR SHOULD REACH
INTO OUR NW COUNTIES BY SUNRISE AS THE FRONT MOVES THROUGH.


&&

.PREV DISCUSSION... /ISSUED 708 PM CDT MON MAY 18 2015/

UPDATE...
UPDATED FOR 00Z AVIATION DISCUSSION.

AVIATION.../00Z TAFS/
GENERALLY VFR CONDITIONS CAN BE EXPECTED OVER NEXT 24 HOURS WITH
EXCEPTION OF KCSV WHERE MVFR/IFR VISIBILITIES AND CEILINGS WILL
DEVELOP BETWEEN 05Z-16Z WITH THE WORST CONDITIONS EXPECTED BETWEEN
09Z-14Z.

PREV DISCUSSION... /ISSUED 309 PM CDT MON MAY 18 2015/

DISCUSSION...

LATEST RADAR IMAGERY SHOWS SCATTERED SHOWERS AND A COUPLE OF
THUNDERSTORMS HAVE DEVELOPED THROUGHOUT THE MID STATE WITH THE
HEAVIEST CONCENTRATION SOUTH OF I-40. EXPECT THIS ACTIVITY TO
CONTINUE SPREADING EASTWARD THROUGH THE AFTERNOON. SHOWERS AND
STORMS WILL DIMINISH THIS EVENING AND TONIGHT AS A COLD FRONT
CURRENTLY IN SE MO AND S IL MOVES ACROSS THE AREA LATE TONIGHT
AND TOMORROW. MOISTURE WILL LINGER OVER SOUTHEASTERN ZONES
ON TUESDAY PRIOR TO FROPA SO COULD STILL SEE SOME ISOLATED SHOWERS
OR STORMS.

SOMEWHAT COOLER AND DRIER WEATHER IS OTHERWISE EXPECTED TUESDAY
INTO WEDNESDAY BEFORE THE NEXT SYSTEM APPROACHES FROM THE PLAINS.
NAM/ECMWF ARE MUCH MORE AGGRESSIVE THAN THE GFS IN BRINGING
NUMEROUS SHOWERS AND STORMS ACROSS THE AREA LATE WEDNESDAY INTO
EARLY THURSDAY. THEIR DEGREE OF MOISTURE RETURN FROM THE GULF MAY
BE TOO AGGRESSIVE...BUT WILL STILL GO AHEAD AND BUMP UP POPS FOR
THIS TIME FRAME. REMAINDER OF THE WEEK LOOKS QUITE NICE WITH LOWS
IN THE 50S AND HIGHS IN THE 70S.

GLOBAL MODELS AGREE THAT MIDDLE TENNESSEE WILL TRANSITION
INTO A WARMER BUT WETTER PATTERN OVER THE MEMORIAL DAY WEEKEND AS
THE PERSISTENT UPPER RIDGE OVER THE SOUTHEAST CONUS SHIFTS MORE
INTO THE ATLANTIC OCEAN...ALLOWING THE ACTIVE SUBTROPICAL JET TO
SHIFT FURTHER TO THE SOUTH OVER OUR REGION. THUS RAIN CHANCES WILL
INCREASE FROM SUNDAY ONWARD WITH HIGHS RETURNING INTO THE 80S AND
LOWS IN THE 60S.

&&

.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

21





AREA FORECAST DISCUSSION

NWS MEMPHIS TN

 304 PM CDT SUN MAY 17 2015

.DISCUSSION...

THE MIDSOUTH REMAINS STUCK UNDERNEATH SOUTHWEST FLOW ALOFT. THE
SOUTHWEST FLOW ALOFT HAS BROUGHT THIS WET PATTERN TO THE REGION AS
THE COMBINATION OF SHORTWAVES MOVING THROUGH THE FLOW AND AN
ABUNDANCE OF MOISTURE FROM THE GULF OF MEXICO HAS PRODUCED ROUND
AFTER ROUND OF SHOWERS AND THUNDERSTORMS.

LOOKING AT LATEST RADAR IMAGES...MOST OF THE SHOWER AND
THUNDERSTORM ACTIVITY HAS NOW PUSHED EAST OF THE MISSISSIPPI
RIVER. MOST OF THIS CONVECTION WILL LIKELY PUSH EAST OF THE CWA BY
7 PM. HOWEVER...LATEST HRRR SHOWS REDEVELOPMENT OCCURRING OVER
NORTHEAST ARKANSAS BY THAT TIME. THE CORRIDOR FROM NORTHEAST
ARKANSAS AND THE MISSOURI BOOTHEEL MAY SEE MOST OF THE CONVECTION
DURING THE LATE EVENING INTO THE OVERNIGHT HOURS BEFORE IT SHIFTS
SOUTHWARD ON MONDAY. HAVE ADJUSTED POPS ACCORDINGLY. IN
ADDITION...SINCE THERE ARE PORTIONS OF NORTHEAST MISSISSIPPI THAT
HAS SEEN SEVERAL ROUNDS OF HEAVY SHOWERS TODAY...WILL GO AHEAD AND
EXPAND THE FLASH FLOOD WATCH SOUTHWARD TO COVER THE ENTIRE CWA
THROUGH MONDAY.

MONDAY WILL BE ANOTHER RAINY DAY FOR THE MIDSOUTH WITH OFF AND ON
PERIODS OF HEAVY SHOWERS AND THUNDERSTORMS. EXPECT HIGHS IN THE
UPPER 70S TO LOWER 80S.

THE COLD FRONT WILL FINALLY BEGIN TO PUSH INTO THE AREA MONDAY
NIGHT INTO TUESDAY. MODELS ARE COMING INTO TO CLOSER AGREEMENT
THAT THE FRONT WILL STALL OUT JUST SOUTH OF THE CWA AND BEGIN
LIFTING BACK NORTHWARD AS A WARM FRONT LATE TUESDAY NIGHT INTO
WEDNESDAY. THIS WILL KEEP SMALL CHANCES FOR SHOWERS AND
THUNDERSTORMS IN THE FORECAST FOR PORTIONS OF EAST-CENTRAL
ARKANSAS AND NORTH MISSISSIPPI WHILE GIVING THE REST OF THE CWA
ONL A BRIEF REPRIEVE ON TUESDAY NIGHT.

BY WEDNESDAY...THE ENTIRE MIDSOUTH WILL SEE CHANCES FOR SHOWERS
AND THUNDERSTORMS AGAIN AS A WEAK SHORTWAVE MOVES ACROSS THE CWA.
BETTER CHANCES FOR SHOWERS AND THUNDERSTORMS WILL COME WEDNESDAY
NIGHT INTO THURSDAY AS THE FRONT MOVES BACK THROUGH THE AREA AS A
COLD FRONT.

HIGH PRESSURE WILL BUILD INTO THE AREA THURSDAY NIGHT THROUGH
SATURDAY. NO PRECIPITATION IS EXPECTED AS A RESULT. HIGHS WILL BE
IN THE MID 70S TO LOWER 80S. LOWS WILL BE IN THE MID 50S TO LOWER
60S.

LOOKS LIKE THE MIDSOUTH COULD BE UNDERNEATH SOUTHWEST FLOW ALOFT
AGAIN BY SATURDAY NIGHT CONTINUING INTO EARLY NEXT WEEK. THIS
COULD BRING ANOTHER EXTENDED WET PERIOD TO THE REGION.

KRM

&&

.AVIATION...

18Z TAFS

MVFR CIGS WILL TO LIFT TO VFR BY 19Z OR SHORTLY THEREAFTER. VFR
CONDS EXPECTED THIS AFTERNOON AND THIS EVENING OUTSIDE OF SHRAS
AND TSRAS. CARRIED VCTS AT ALL TERMINALS THIS AFTERNOON UNTIL
18/00Z WITH LOSS OF HEATING. SHORT RANGE MODELS INDICATE MORE
TSRAS EXPECTED TO FIRE UP ACROSS NE ARKANSAS THIS EVENING SO
PREDOMINANT TSRA FROM 18/02Z-18/06Z LOOKS GOOD. MODELS DISAGREE ON
HOW WIDESPREAD LOW CLOUDS LATER TONIGHT AND MON MORNING. BEST
CHANCES APPEAR TO BE AT KTUP AND PLACED A MVFR CIG THERE MONDAY
MORNING OTRW WILL GO WITH OPTIMISTIC FORECAST. MORE TSRAS
POSSIBLE LATER MON AM INTO THE AFTN.

SOUTH WINDS 10-12 KTS WITH HIGHER GUSTS THIS AFTN...8-10 KTS
TONIGHT.

SJM

&&

.MEG WATCHES/WARNINGS/ADVISORIES...
AR...FLASH FLOOD WATCH THROUGH MONDAY EVENING FOR CLAY-CRAIGHEAD-
     CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-MISSISSIPPI-
     PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS.

MO...FLASH FLOOD WATCH THROUGH MONDAY EVENING FOR DUNKLIN-PEMISCOT.

MS...FLASH FLOOD WATCH THROUGH MONDAY EVENING FOR ALCORN-BENTON MS-
     CALHOUN-CHICKASAW-COAHOMA-DESOTO-ITAWAMBA-LAFAYETTE-LEE MS-
     MARSHALL-MONROE-PANOLA-PONTOTOC-PRENTISS-QUITMAN-
     TALLAHATCHIE-TATE-TIPPAH-TISHOMINGO-TUNICA-UNION-YALOBUSHA.

TN...FLASH FLOOD WATCH THROUGH MONDAY EVENING FOR BENTON TN-CARROLL-
     CHESTER-CROCKETT-DECATUR-DYER-FAYETTE-GIBSON-HARDEMAN-
     HARDIN-HAYWOOD-HENDERSON-HENRY-LAKE-LAUDERDALE-MADISON-
     MCNAIRY-OBION-SHELBY-TIPTON-WEAKLEY.

&&

$$



AREA FORECAST DISCUSSION

NWS MEMPHIS TN

 1139 PM CDT SAT MAY 16 2015

.UPDATE...AVIATION DISCUSSION.

&&

.PREV DISCUSSION... /ISSUED 900 PM CDT SAT MAY 16 2015/

DISCUSSION...WATER VAPOR SATELLITE/WSR-88D VAD WIND PROFILES
INDICATE A COUPLE OF SHORTWAVE TROUGH LOCATED ACROSS THE LOWER
MISSISSIPPI VALLEY THIS EVENING. THE FIRST SHORTWAVE IS LOCATED
OVER WEST TENNESSEE AND THE SECOND SHORTWAVE LOCATED OVER
CENTRAL/SOUTHERN MISSISSIPPI THIS EVENING. OVERALL CONVECTIVE
ACTIVITY HAS BEEN DIMINISHING WITH THE LOSS OF DAYTIME
INSTABILITY AND WITH THESE SHORTWAVES MOVING AWAY FROM THE MID
SOUTH. LATEST HRRR/00Z WRF AGREE WITH SHOWERS AND THUNDERSTORMS
DIMINISHING WITH COVERAGE THROUGHOUT THE REMAINDER OF THE NIGHT.
WILL UPDATE POPS AND ALL OTHER ELEMENTS TO REFLECT CURRENT TRENDS.

UPDATED GRIDS WILL BE AVAILABLE SHORTLY.

CJC

PREV DISCUSSION... /ISSUED 627 PM CDT SAT MAY 16 2015/

UPDATE...AVIATION DISCUSSION.

PREV DISCUSSION... /ISSUED 311 PM CDT SAT MAY 16 2015/

POPCORN TYPE SHOWERS AND THUNDERSTORMS ARE OCCURRING ACROSS THE
MIDSOUTH AND SURROUNDING AREAS. LATEST HRRR SHOWS THIS ACTIVITY
CONTINUING THROUGH AROUND 7-8 PM. THEREAFTER...ACTIVITY WILL
DISSIPATE FROM THE LOSS OF DAYTIME HEATING. EXPECT THE REMAINDER
OF THE NIGHT TO BE TRANQUIL. WILL LEAVE 30 POPS IN CASE A STRAY
SHOWER OR THUNDERSTORM DEVELOPS. LOWS WILL BE IN THE MID TO UPPER
60S.

A SEVERE LINE OF SHOWERS AND THUNDERSTORMS IS EXPECTED TO DEVELOP
THIS EVENING ACROSS OKLAHOMA...KANSAS...AND TEXAS. MODELS HAVE
BEEN PRETTY CONSISTENT WITH BRINGING THE REMNANTS OF THIS LINE
INTO EASTERN ARKANSAS AROUND SUNRISE. STILL EXPECT THE LINE TO BE
IN THE DYING PHASES AS IT MOVES IN. THE LINE WILL FALL APART AS IT
REACHES THE MS RIVER DURING THE MORNING. HOWEVER...REDEVELOPMENT
ALONG LEFTOVER BOUNDARIES WILL BE POSSIBLE ALONG AND EAST OF THE
MISSISSIPPI RIVER FROM MID-MORNING ON SUNDAY INTO THE AFTERNOON
HOURS.

EXPECT SHOWER AND THUNDERSTORM ACTIVITY TO DIE OUT AGAIN BY 7PM
SUNDAY EVENING. NEW DEVELOPMENT MAY OCCUR ALONG AND WEST OF THE
MISSISSIPPI RIVER DURING THE LATE EVENING TO OVERNIGHT HOURS AS A
SHORTWAVE MOVES INTO THE REGION. THIS ACTIVITY WILL BLOSSOM OVER
THE CWA INTO MONDAY.

THE COLD FRONT IS STILL EXPECTED TO MOVE INTO THE AREA MONDAY
NIGHT INTO TUESDAY. SCATTERED CHANCES FOR SHOWERS AND
THUNDERSTORMS WILL CONTINUE ALONG AND AHEAD OF THE FRONT.

THE ECMWF AND GFS DIFFER ON HOW2 FAR SOUTH THE FRONT WILL
PROGRESS. IF THE ECMWF IS CORRECT...TUESDAY NIGHT MAY BE THE ONLY
DRY PERIOD BEFORE THE FRONT MOVES BACK NORTH AS A WARM FRONT.
CHANCES FOR SHOWERS AND THUNDERSTORMS WILL OCCUR ALONG AND AHEAD
OF THE WARM FRONT. THE FRONT WILL RETURN SOUTHWARD AS A COLD FRONT
ON THURSDAY. BEST CHANCES FOR SHOWERS AND THUNDERSTORMS WILL
LIKELY OCCUR ON THURSDAY.

HIGH PRESSURE WILL THEN BUILD INTO THE AREA ON FRIDAY.


&&

.AVIATION...06Z TAFS

QUIET OVERNIGHT WITH LOW CLOUDS DEVELOPING TOWARD MORNING.
GUIDANCE HAS CIGS AS LOW AS 500 FT...BUT THAT IS PROBABLY A BIT
PESSIMISTIC. WILL TEMPO MVFR CIGS FOR A FEW HOURS AROUND SUNRISE
AT MEM AND MKL...WITH PREVAILING MVFR CIGS AT JBR AND TUP.
SHORT RANGE GUIDANCE IS A BIT LESS BULLISH WITH REDEVELOPMENT
EARLY TOMORROW. WILL DELAY THE INTRODUCTION OF VCTS UNTIL MID TO
EARLY AFTERNOON AS A LINE OF STORMS IS EXPECTED TO APPROACH FROM
THE WEST. ANY EARLY DEVELOPMENT...OR DEVELOPMENT AHEAD OF THE LINE
CAN BE HANDLED WITH AMENDMENTS. TEMPORARY IFR OR LIFR VIS CAN BE
EXPECTED WITH ANY THUNDERSTORMS...BUT PREVAILING CONDITIONS SHOULD
REMAIN MVFR TO VFR.

SOUTH WINDS AROUND 10KTS TONIGHT...INCREASING TO 10-15KTS TOMORROW
WITH GUSTS TO 25KT. HIGHER GUSTS NEAR THUNDERSTORMS.

30

&&

.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&

$$



AREA FORECAST DISCUSSION

NWS HOUSTON/GALVESTON TX

 955 PM CDT MON MAY 18 2015

.DISCUSSION...
WITH THE LOSS OF DAYTIME HEATING...THE SHOWERS AND THUNDERSTORMS
HAVE DISSIPATED BETWEEN HOUSTON AND COLLEGE STATION. HOWEVER...AN
ANALYSIS OF THE 00Z SURFACE AND UPPER AIR CHARTS SHOWED A SURFACE
OUTFLOW BOUNDARY LOCATED FROM HOUSTON TO BRENHAM...850 MB
DEWPOINTS BETWEEN 10 AND 12 CELCIUS AND 700 MB DEWPOINTS BETWEEN 2
AND 4 CELCIUS OVER THE SURFACE BOUNDARY...A 500 MB SHORTWAVE
TROUGH MOVING EASTWARD ACROSS WEST TEXAS...AND A DIFFLUENT ZONE
OVERHEAD SE TEXAS AT 300 AND 200 MB. THE NAMBUFR FORECAST
SOUNDINGS GIVE MU CAPE VALUES OF AT LEAST 2700 SOUTH OF THE
OUTFLOW BOUNDARY BETWEEN MIDNIGHT AND 6 AM AND INCREASED THIS TO
OVER 3000 AFTER SUNRISE. THE HIGH RESOLUTION SHORT TERM MODELS
ALL SHOWED THE DISSIPATING EVENING SHOWERS AND THUNDERSTORMS.
HOWEVER...THE RAP13 HAS DONE THE BEST JOB SO FAR AND FORECASTS A
BEGINNING OF CONVECTION ALONG THE OUTFLOW BOUNDARY ALONG THE
INTERSTATE 10 CORRIDOR AROUND AND AFTER SUNRISE TUESDAY MORNING.

FOR THE UPDATE...COULD NOT RULE OUT ISOLATED SHOWERS AND
THUNDERSTORMS OVERNIGHT TONIGHT...AND KEPT THE POPS AT 20 PERCENT
FROM LATE THIS EVENING THROUGH 7 AM. UPPED THE POPS TO 30 PERCENT
FOR THE INTERSTATE 10 CORRIDOR FOR THE FIRST HALF OF TUESDAY
MORNING AND THEN EXTENDED THE SCATTERED POPS NORTHWARD FOR THE
LAST HALF OF THE MORNING. WOULD NOT BE SURPRISED IF THE ACTIVITY
BEGINS BEFORE SUNRISE...HOWEVER IF THE RAP13 IS ON TARGET...THE
COVERAGE WILL BE ISOLATED WHICH IS CURRENTLY COVERED WITH THE 20
PERCENT POPS. WILL NEED TO MONITOR THE THREAT FOR LOCALLY HEAVY
RAINFALL. THE MODEL IS NOT INDICATING PW/S MUCH HIGHER THAN 1.6
INCHES AT THIS TIME...HOWEVER IF SLOW MOVING STORMS DEVELOP EVEN A
1 TO 2 INCH PER HOUR RAINFALL RATE WOULD POISE A PROBLEM.

UPDATED POPS AND WEATHER FOR THE REMAINDER OF THIS EVENING AND THE
TUESDAY MORNING TIME PERIODS.

40

&&

.PREV DISCUSSION... /ISSUED 723 PM CDT MON MAY 18 2015/

UPDATE...
A COUPLE OF OUTFLOW BOUNDARIES WERE MOVING SOUTHWESTWARD ACROSS
THE CENTRAL PORTIONS OF THE FORECAST AREA. UPDATE TO ADD SLIGHTER
BETTER CHANCES FOR SHOWERS AND THUNDERSTORMS OVER THE WEST-CENTRAL
SET OF COUNTIES THROUGH THE REST OF THE EVENING. THE 23Z HRRR
INITIALIZED WELL WITH THE CURRENT SHOWERS AND THUNDERSTORMS. THE
MODELS THEN KEEPS AT LEAST ISOLATED CONVECTION GOING BETWEEN 9 PM
AND MIDNIGHT.

40

PREV DISCUSSION... /ISSUED 650 PM CDT MON MAY 18 2015/

DISCUSSION...
00Z TAF DISCUSSION IN AVIATION SECTION...

AVIATION...
VIS SATELLITE AND RADAR SHOW OUTFLOW BOUNDARY PUSHING INTO THE
HOUSTON AREA FROM THE EAST. THERE HAVE BEEN SOME NEW STORMS TO
DEVELOP BUT LOOKS LIKE MOISTURE/INSTABILITY MAY HAVE BEEN WORKED
OVER JUST ENOUGH THAT THE STORMS ARE NOT AS STRONG AS THEY COULD
BE OTHERWISE. STORMS ARE MAINLY IMPACTING KCXO BUT COULD SEE A FEW
CONVECTIVE CELLS DEVELOP THROUGH THE EVENING AROUND KIAH/KUTS.
MENTION VCTS FOR MOST TAF SITES UNTIL 02Z BUT AT LEAST TEMPO TSRA
FOR CXO AND UTS.

TONIGHT EXPECT MAINLY MVFR CIGS TO DEVELOP AS HAS BEEN THE CASE
THE LAST FEW NIGHTS. REMNANT OUTFLOW BOUNDARY MAY SET UP EAST/WEST
ACROSS THE AREA. THINK LATEST RAP/HRRR SEEM TO HAVE A HANDLE ON
THIS EVOLUTION. RAP ALSO DEVELOPS CONVECTION ALONG THIS BOUNDARY
IN THE MORNING. WATER VAPOR IMAGERY SHOWS SHORT WAVE TROUGH OVER
MEXICO/W TX/BIG BEND AREA THAT COULD IMPACT THE AREA BY LATE
MORNING. WITH DAYTIME HEATING DECIDED TO PUT VCTS IN TAFS STARTING
16Z WITH VCSH PRIOR TO THAT.

39

&&

.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL)      73  85  72  87  71 /  20  40  10  20  30
HOUSTON (IAH)              73  86  73  88  74 /  20  30  10  30  10
GALVESTON (GLS)            77  83  77  85  77 /  20  20  10  10  10

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&

$$

DISCUSSION...40
AVIATION/MARINE...39



AREA FORECAST DISCUSSION

NWS HOUSTON/GALVESTON TX

 723 PM CDT MON MAY 18 2015

.UPDATE...
A COUPLE OF OUTFLOW BOUNDARIES WERE MOVING SOUTHWESTWARD ACROSS
THE CENTRAL PORTIONS OF THE FORECAST AREA. UPDATE TO ADD SLIGHTER
BETTER CHANCES FOR SHOWERS AND THUNDERSTORMS OVER THE WEST-CENTRAL
SET OF COUNTIES THROUGH THE REST OF THE EVENING. THE 23Z HRRR
INITIALIZED WELL WITH THE CURRENT SHOWERS AND THUNDERSTORMS. THE
MODELS THEN KEEPS AT LEAST ISOLATED CONVECTION GOING BETWEEN 9 PM
AND MIDNIGHT.

40

&&

.PREV DISCUSSION... /ISSUED 650 PM CDT MON MAY 18 2015/

DISCUSSION...
00Z TAF DISCUSSION IN AVIATION SECTION...

AVIATION...
VIS SATELLITE AND RADAR SHOW OUTFLOW BOUNDARY PUSHING INTO THE
HOUSTON AREA FROM THE EAST. THERE HAVE BEEN SOME NEW STORMS TO
DEVELOP BUT LOOKS LIKE MOISTURE/INSTABILITY MAY HAVE BEEN WORKED
OVER JUST ENOUGH THAT THE STORMS ARE NOT AS STRONG AS THEY COULD
BE OTHERWISE. STORMS ARE MAINLY IMPACTING KCXO BUT COULD SEE A FEW
CONVECTIVE CELLS DEVELOP THROUGH THE EVENING AROUND KIAH/KUTS.
MENTION VCTS FOR MOST TAF SITES UNTIL 02Z BUT AT LEAST TEMPO TSRA
FOR CXO AND UTS.

TONIGHT EXPECT MAINLY MVFR CIGS TO DEVELOP AS HAS BEEN THE CASE
THE LAST FEW NIGHTS. REMNANT OUTFLOW BOUNDARY MAY SET UP EAST/WEST
ACROSS THE AREA. THINK LATEST RAP/HRRR SEEM TO HAVE A HANDLE ON
THIS EVOLUTION. RAP ALSO DEVELOPS CONVECTION ALONG THIS BOUNDARY
IN THE MORNING. WATER VAPOR IMAGERY SHOWS SHORT WAVE TROUGH OVER
MEXICO/W TX/BIG BEND AREA THAT COULD IMPACT THE AREA BY LATE
MORNING. WITH DAYTIME HEATING DECIDED TO PUT VCTS IN TAFS STARTING
16Z WITH VCSH PRIOR TO THAT.

39

PREV DISCUSSION... /ISSUED 355 PM CDT MON MAY 18 2015/

DISCUSSION...
SCATTERED SHRA/TSRA HAVE DEVELOPED OVER THE EXTREME EASTERN AND
NORTHWESTERN PORTIONS OF THE AREA. THESE STORMS HAVE THE
POSSIBILITY OF PRODUCING LOCALIZED FLOODING, ESPECIALLY IN AREAS
WITH AN ALREADY SATURATED GROUND. THE STORMS IN DEEP SE TEXAS ARE
BEING ENHANCED BY A REMNANT OUTFLOW BOUNDARY MOVING W-SW. INTO THE
EVENING, THE LOSS OF HEATING WILL DROP THE PRECIP CHANCES TO 20%
OVERNIGHT. SUSTAINED ONSHORE FLOW OVER NEXT SEVERAL DAYS WILL
CONTINUE TO ALLOW FOR SCATTERED SHRA/TSRA TO DEVELOP IN THE
AFTERNOON HOURS WITH THE PASSAGE OF ANY SHORTWAVE TROUGH OR IN
AREAS OF ENHANCED SURFACE CONVERGENCE.

EARLY WED MORNING...A SURFACE LOW WILL DEVELOP AS A MID LEVEL LOW
EJECTS OUT OF THE ROCKIES. THE ASSOCIATED COLD FRONT WILL
PROGRESS INTO THE AREA WED NIGHT-THURS, INCREASING THE RAIN
CHANCES THURSDAY.

THE EXTENDED FORECAST...FRIDAY, THE BOUNDARY WILL WEAKEN/MOVE
NORTH, ALLOWING FOR SUSTAINED SE FLOW TO PROVIDE A MOISTURE
SOURCE FOR SCATTERED SHRA/TSRA DEVELOPMENT OVER THE WEEKEND.
TOWARDS THE END OF THE WEEKEND, ANOTHER UPPER LEVEL LOW WILL EJECT
OUT OF THE ROCKIES DEVELOPING ANOTHER SURFACE LOW AND COLD FRONTAL
BOUNDARY EARLY NEXT WEEK.

DSB

MARINE...

RELATIVELY QUIET CONDITIONS IN PLACE ACROSS THE MARINE AREAS THIS
AFTERNOON... WITH A FEW ISOLATED SHOWERS DEVELOPING OVER THE EASTERN
WATERS. COULD SEE ADDITIONAL SHOWERS OR STORMS OVER THE COASTAL
WATERS TONIGHT AS AN OUTFLOW BOUNDARY MOVES OUT OF LOUISIANA AND
INTO THE GULF AS WELL AS OVER THE NEXT FEW DAYS AS UPPER LEVEL
DISTURBANCES TRACK NEAR THE REGION... BUT CHANCES LOOK TO DIMINISH
BY THE END OF THE WEEK AS AN UPPER RIDGE NOSES INTO THE REGION. A
FRONTAL BOUNDARY SAGS TOWARDS SOUTHEAST TEXAS WEDNESDAY NIGHT INTO
THURSDAY... BUT CONFIDENCE IS LOW THAT THIS FEATURE WILL REACH THE
COASTAL WATERS WITH SURFACE PRESSURE RISES DECREASING BEHIND THE
FRONT AS IT APPROACHES. CAN/T RULE OUT A MORE EASTERLY FETCH
DEVELOPING IN RESPONSE WITH SOME SLIGHTLY ELEVATED TIDES DURING THIS
TIME HOWEVER. LOOKING AHEAD TO THE HOLIDAY WEEKEND... ONSHORE FLOW
INCREASES IN RESPONSE TO A DEVELOPING SURFACE LOW OVER THE HIGH
PLAINS SATURDAY INTO SUNDAY. THIS WILL CONTINUE CONCERNS FOR RIP
CURRENT RISKS ALONG THE COAST.

OTHERWISE... LIGHT TO OCCASIONALLY MODERATE ONSHORE FLOW EXPECTED TO
PERSIST OVER THE NEXT SEVERAL DAYS... WITH SEAS GENERALLY 2 TO 4
FEET.

HUFFMAN

PREV DISCUSSION... /ISSUED 1256 PM CDT MON MAY 18 2015/

AVIATION...
FOR THE 18Z TAFS... MORNING STORMS HAVE CLEARED THE TERMINALS BUT
REMNANT CLOUD DEBRIS IS DOING LITTLE TO SUPPRESS HEATING WITH MANY
SITES APPROACHING CONVECTIVE TEMPERATURES. ISOLATED TO SCATTERED
THUNDERSTORMS WILL BE POSSIBLE AGAIN DURING THE AFTERNOON FOR THE
TERMINALS... WITH THE BEST CHANCES FOR TERMINALS ALONG AND SOUTH
OF INTERSTATE 10 /KIAH...KSGR...KHOU...KLBX...AND KGLS/ AS THE
ATMOSPHERE FARTHER NORTH HAS STABILIZED SOMEWHAT IN THE WAKE OF
THIS MORNING/S ACTIVITY. OTHERWISE... VFR CONDITIONS THIS
AFTERNOON EXPECTED TO DETERIORATE TO MVFR TONIGHT AS CEILINGS
LOWER WITH SOUTHEASTERLY WINDS BECOMING LIGHT AND VARIABLE. COULD
SEE SOME PATCHY OVERNIGHT FOG AS WELL... BUT ONLY HIGHLIGHTING
CATEGORY CHANGES FOR VISIBILITIES AT KCXO AND KUTS FOR NOW.

HUFFMAN

&&

.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL)      73  85  72  87  71 /  30  40  10  20  30
HOUSTON (IAH)              73  86  73  88  74 /  20  30  10  30  10
GALVESTON (GLS)            77  83  77  85  77 /  20  20  10  10  10

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&

$$

DISCUSSION...40
AVIATION/MARINE...39




AREA FORECAST DISCUSSION

NWS HOUSTON/GALVESTON TX

 650 PM CDT MON MAY 18 2015

.DISCUSSION...
00Z TAF DISCUSSION IN AVIATION SECTION...

&&

.AVIATION...
VIS SATELLITE AND RADAR SHOW OUTFLOW BOUNDARY PUSHING INTO THE
HOUSTON AREA FROM THE EAST. THERE HAVE BEEN SOME NEW STORMS TO
DEVELOP BUT LOOKS LIKE MOISTURE/INSTABILITY MAY HAVE BEEN WORKED
OVER JUST ENOUGH THAT THE STORMS ARE NOT AS STRONG AS THEY COULD
BE OTHERWISE. STORMS ARE MAINLY IMPACTING KCXO BUT COULD SEE A FEW
CONVECTIVE CELLS DEVELOP THROUGH THE EVENING AROUND KIAH/KUTS.
MENTION VCTS FOR MOST TAF SITES UNTIL 02Z BUT AT LEAST TEMPO TSRA
FOR CXO AND UTS.

TONIGHT EXPECT MAINLY MVFR CIGS TO DEVELOP AS HAS BEEN THE CASE
THE LAST FEW NIGHTS. REMNANT OUTFLOW BOUNDARY MAY SET UP EAST/WEST
ACROSS THE AREA. THINK LATEST RAP/HRRR SEEM TO HAVE A HANDLE ON
THIS EVOLUTION. RAP ALSO DEVELOPS CONVECTION ALONG THIS BOUNDARY
IN THE MORNING. WATER VAPOR IMAGERY SHOWS SHORT WAVE TROUGH OVER
MEXICO/W TX/BIG BEND AREA THAT COULD IMPACT THE AREA BY LATE
MORNING. WITH DAYTIME HEATING DECIDED TO PUT VCTS IN TAFS STARTING
16Z WITH VCSH PRIOR TO THAT.

39

&&

.PREV DISCUSSION... /ISSUED 355 PM CDT MON MAY 18 2015/

DISCUSSION...
SCATTERED SHRA/TSRA HAVE DEVELOPED OVER THE EXTREME EASTERN AND NORTHWESTERN
PORTIONS OF THE AREA. THESE STORMS HAVE THE POSSIBILITY OF
PRODUCING LOCALIZED FLOODING, ESPECIALLY IN AREAS WITH AN ALREADY
SATURATED GROUND. THE STORMS IN DEEP SE TEXAS ARE BEING ENHANCED
BY A REMNANT OUTFLOW BOUNDARY MOVING W-SW. INTO THE EVENING, THE
LOSS OF HEATING WILL DROP THE PRECIP CHANCES TO 20% OVERNIGHT.
SUSTAINED ONSHORE FLOW OVER NEXT SEVERAL DAYS WILL CONTINUE TO
ALLOW FOR SCATTERED SHRA/TSRA TO DEVELOP IN THE AFTERNOON HOURS
WITH THE PASSAGE OF ANY SHORTWAVE TROUGH OR IN AREAS OF ENHANCED
SURFACE CONVERGENCE.

EARLY WED MORNING...A SURFACE LOW WILL DEVELOP AS A MID LEVEL LOW
EJECTS OUT OF THE ROCKIES. THE ASSOCIATED COLD FRONT WILL
PROGRESS INTO THE AREA WED NIGHT-THURS, INCREASING THE RAIN
CHANCES THURSDAY.

THE EXTENDED FORECAST...FRIDAY, THE BOUNDARY WILL WEAKEN/MOVE
NORTH, ALLOWING FOR SUSTAINED SE FLOW TO PROVIDE A MOISTURE
SOURCE FOR SCATTERED SHRA/TSRA DEVELOPMENT OVER THE WEEKEND.
TOWARDS THE END OF THE WEEKEND, ANOTHER UPPER LEVEL LOW WILL EJECT
OUT OF THE ROCKIES DEVELOPING ANOTHER SURFACE LOW AND COLD FRONTAL
BOUNDARY EARLY NEXT WEEK.

DSB

MARINE...

RELATIVELY QUIET CONDITIONS IN PLACE ACROSS THE MARINE AREAS THIS
AFTERNOON... WITH A FEW ISOLATED SHOWERS DEVELOPING OVER THE EASTERN
WATERS. COULD SEE ADDITIONAL SHOWERS OR STORMS OVER THE COASTAL
WATERS TONIGHT AS AN OUTFLOW BOUNDARY MOVES OUT OF LOUISIANA AND
INTO THE GULF AS WELL AS OVER THE NEXT FEW DAYS AS UPPER LEVEL
DISTURBANCES TRACK NEAR THE REGION... BUT CHANCES LOOK TO DIMINISH
BY THE END OF THE WEEK AS AN UPPER RIDGE NOSES INTO THE REGION. A
FRONTAL BOUNDARY SAGS TOWARDS SOUTHEAST TEXAS WEDNESDAY NIGHT INTO
THURSDAY... BUT CONFIDENCE IS LOW THAT THIS FEATURE WILL REACH THE
COASTAL WATERS WITH SURFACE PRESSURE RISES DECREASING BEHIND THE
FRONT AS IT APPROACHES. CAN/T RULE OUT A MORE EASTERLY FETCH
DEVELOPING IN RESPONSE WITH SOME SLIGHTLY ELEVATED TIDES DURING THIS
TIME HOWEVER. LOOKING AHEAD TO THE HOLIDAY WEEKEND... ONSHORE FLOW
INCREASES IN RESPONSE TO A DEVELOPING SURFACE LOW OVER THE HIGH
PLAINS SATURDAY INTO SUNDAY. THIS WILL CONTINUE CONCERNS FOR RIP
CURRENT RISKS ALONG THE COAST.

OTHERWISE... LIGHT TO OCCASIONALLY MODERATE ONSHORE FLOW EXPECTED TO
PERSIST OVER THE NEXT SEVERAL DAYS... WITH SEAS GENERALLY 2 TO 4
FEET.

HUFFMAN

PREV DISCUSSION... /ISSUED 1256 PM CDT MON MAY 18 2015/

AVIATION...
FOR THE 18Z TAFS... MORNING STORMS HAVE CLEARED THE TERMINALS BUT
REMNANT CLOUD DEBRIS IS DOING LITTLE TO SUPPRESS HEATING WITH MANY
SITES APPROACHING CONVECTIVE TEMPERATURES. ISOLATED TO SCATTERED
THUNDERSTORMS WILL BE POSSIBLE AGAIN DURING THE AFTERNOON FOR THE
TERMINALS... WITH THE BEST CHANCES FOR TERMINALS ALONG AND SOUTH
OF INTERSTATE 10 /KIAH...KSGR...KHOU...KLBX...AND KGLS/ AS THE
ATMOSPHERE FARTHER NORTH HAS STABILIZED SOMEWHAT IN THE WAKE OF
THIS MORNING/S ACTIVITY. OTHERWISE... VFR CONDITIONS THIS
AFTERNOON EXPECTED TO DETERIORATE TO MVFR TONIGHT AS CEILINGS
LOWER WITH SOUTHEASTERLY WINDS BECOMING LIGHT AND VARIABLE. COULD
SEE SOME PATCHY OVERNIGHT FOG AS WELL... BUT ONLY HIGHLIGHTING
CATEGORY CHANGES FOR VISIBILITIES AT KCXO AND KUTS FOR NOW.

HUFFMAN

&&

.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL)      73  85  72  87  71 /  20  40  10  20  30
HOUSTON (IAH)              73  86  73  88  74 /  20  30  10  30  10
GALVESTON (GLS)            77  83  77  85  77 /  20  20  10  10  10

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&

$$

DISCUSSION...40
AVIATION/MARINE...39




AREA FORECAST DISCUSSION...UPDATED

NWS CORPUS CHRISTI TX

 1251 PM CDT SUN MAY 17 2015

.DISCUSSION...UPDATED FOR 18Z AVIATION.

&&

.AVIATION...LOWER CONFIDENCE WIND FORECAST AS A COUPLE OF OUTFLOW
BOUNDARIES ARE PRESENT ACROSS SOUTH TEXAS. SHOWERS AND ISOLATED
THUNDERSTORMS CONTINUE TO IMPACT THE VCT TERMINAL AND WILL PREVAIL
TSRA FOR A SHORT INTERVAL. ANTICIPATE CONVECTION OVER THE NE WILL
PUSH OFF TO THE EAST AND NE. ADDITIONAL SHOWERS AND STORMS WILL BE
POSSIBLE LATER THIS AFTERNOON AND EVENING...MOST LIKELY TO IMPACT
THE ALI AND LRD TERMINALS. MIX OF MVFR/LOW END VFR CONDITIONS THIS
AFTERNOON WILL TRANSITION TO MOSTLY MVFR TONIGHT. SOME POSSIBILITY
OF IFR CIGS TO DEVELOP...BUT NOT CONFIDENT ENOUGH TO INCLUDE IN
THE FORECAST.

&&

.PREV DISCUSSION... /ISSUED 1147 AM CDT SUN MAY 17 2015/

DISCUSSION...EARLIER MCS CONTINUES TO WEAKEN AS EVIDENT WITH
CLOUD TOPS WARMING OVER THE NORTHERN AREAS. LAST OF THE ACTIVITY
FOR NOW REMAINS OVER THE VICTORIA CROSSROADS WHERE SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS ARE ONGOING. CONVECTION SHOULD
PUSH OFF TO THE EAST AND NORTHEAST INTO THE EARLY AFTERNOON. MAIN
REASON FOR THE UPDATE WAS FRESHEN UP THE FORECAST BASED ON LATEST
TRENDS AND EXPIRE SCA AS WINDS HAVE FALLEN BELOW 20 KNOTS .

ATTENTION WILL THEN WILL TURN TO OUT WEST LATER ON THIS EVENING.
LATEST SPC MESOANALYSIS INDICATES INCREASING INSTABILITY BY LATE
THIS AFTERNOON WITH MLCAPES AOA 3500 J/KG. OUTFLOW FROM EARLIER
CONVECTION MAY FOCUS REDEVELOPMENT OF SHOWERS AND THUNDERSTORMS.
HRRR HAS BEEN HINTING AT THIS FOR THE LAST SEVERAL RUNS WITH
CONVECTION MOVING NORTHWARD OUT OF DEEP SOUTH TEXAS. CONDITIONAL
RISK OF STRONG TO SEVERE THUNDERSTORMS EXISTS IF CONVECTION DOES
INDEED DEVELOP. ALSO...HEAVY RAIN AND LOCALIZED FLOODING WILL BE A
CONCERN WITH SOILS SATURATED FROM RECENT RAINS.

PREV DISCUSSION... /ISSUED 645 AM CDT SUN MAY 17 2015/

DISCUSSION...STORMS HAVE BUILT BACK ALL THE WAY TO EAGLE PASS BUT
THE OVERALL PROGRESSION OF THE LINE CONTINUES TO SHOW EAST-SOUTHEAST
MOVEMENT. CURRENT 12Z SOUNDING AT CRP SHOWS A DRY LAYER BETWEEN
850-700 MB LAYER. LATEST HRRR AND RAP ALONG WITH 06Z NAM STILL
SHOW THAT STORMS SHOULD SHOW WEAKENING TREND AS THEY REACH SOUTH
TEXAS AND ENCOUNTER NEGATIVE THETA-E ADVECTION OVER THE COASTAL
PLAINS. SEE AVIATION SECTION FOR 12Z TAFS.

AVIATION...LOW LEVEL FLOW OF 30-35 KNOTS HAS LIMITED FOG
POTENTIAL OVER INLAND AREAS. MVFR CIGS ARE PREVALENT OVER THE
REGION THIS MORNING. MESOSCALE CONVECTIVE SYSTEM MOVING OUT OF
THE HILL COUNTRY IS EXPECTED TO WEAKEN AS IT MOVES TOWARD
SOUTH TEXAS. BUT STORMS SHOULD PERSIST AND REACH THE NORTHERN
COUNTIES BETWEEN 13-15Z. MENTIONED VCTS AT ALI BUT KEPT THE
MENTION OF CONVECTION OUT OF CRP TAFS. OUTFLOW BOUNDARY AND
DEEPER MOISTURE MAY LEAD TO ANOTHER ROUND OF CONVECTION OVER
THE BRUSH COUNTRY THAT COULD AFFECT LRD LATE THIS AFTERNOON
AND EVENING. MVFR CIGS WILL LIFT BY LATE MORNING WITH VFR
CONDITIONS EXPECTED TO BE PREVALENT BY 18Z. MVFR CIGS WILL
MOVE BACK INTO THE COASTAL PLAINS BY 00Z MONDAY AND BE
PREVALENT OVER ALL OF THE REGION BY 06Z.

PREV DISCUSSION... /ISSUED 433 AM CDT SUN MAY 17 2015/

SHORT TERM (TODAY THROUGH MONDAY)...ANOTHER MORNING WITH A
DILEMMA WITH REGARDS TO AN UPSTREAM MESOSCALE CONVECTIVE SYSTEM.
ENVIRONMENT FOR SUSTAINING MCS NOT AS GOOD AS FRIDAY. GOES SOUNDER
IMAGE OF PRECIPITABLE WATER SHOWS DRIER AIR OVER THE NORTHWEST
GULF OF MEXICO ADVECTING NORTHWARD INTO THE REGION. CORFIDI
VECTORS INDICATE THE MCS SHOULD CONTINUE MOVING TO THE SOUTHEAST
TOWARD THE NORTHERN BRUSH COUNTRY AND VICTORIA CROSSROADS REGION
THIS MORNING. 00Z HI-RES ARW/NMM AND 03Z SREF STRONGLY INDICATED
THIS MCS WOULD REACH NORTHERN COUNTIES WHILE THE 00Z NAM/00Z TECH
WRF ALONG WITH 08Z HRRR/RAP SHOWED THE SYSTEM WOULD WEAKEN
SUBSTANTIALLY AS IT NEARED THE AREA THIS MORNING. MCS STILL LOOKS
WELL ORGANIZED AND WILL LEAN TOWARD BETTER RAIN CHANCES MAINLY FOR
THE NORTHERN COUNTIES THIS MORNING. MOST OF THE SHORT RANGE MODELS
KEPT THE HIGHER LOW LEVEL THETA-E RIDGE AXIS OVER THE BRUSH
COUNTRY FOR THIS AFTERNOON. A DECENT UPPER LEVEL JET STREAK WILL
BE MOVING ACROSS NORTHERN MEXICO NOSING INTO THE BRUSH COUNTRY
THIS AFTERNOON. COULD SEE REDEVELOPMENT OF CONVECTION ALONG LEFT
OVER BOUNDARIES THAT WILL LINGER INTO THE EVENING HOURS. HI-RES
MODELS INDICATED THERE COULD BE SOME ISOLATED POCKETS OF HEAVY
RAIN FORM OVER THE BRUSH COUNTRY LATE THIS AFTERNOON INTO THIS
EVENING. IF SCENARIO BECOMES A BIT CLEARER LATER TODAY...A FLASH
FLOOD WATCH MAY BE NEEDED FOR THE WESTERN COUNTIES. THE LOWER
THETA-E AIR MASS OVER THE NORTHWEST GULF OF MEXICO WILL MOVE
INLAND INTO THE COASTAL BEND ON MONDAY WITH THE HIGHER MOISTURE
REMAINING ALONG THE RIO GRANDE. KEPT CHANCE POPS WEST TO GHOST
10 PERCENT POPS ALONG THE COAST MONDAY.

MARINE...SCA WILL CONTINUE FOR THE EARLY MORNING HOURS. EXPECT
AS CONVECTION MOVES CLOSER TO THE REGION...GRADIENT WILL DECREASE
WITH WIND SPEEDS FALLING BELOW SCA CRITERIA. WAVE WATCH MODEL
INDICATED SWELLS WILL BE INCREASING TODAY TO 5 TO 6 FEET AND
CONTINUE INTO MONDAY WITH PERIODS OF 7 TO 8 SECONDS. WITH THE
CONTINUED MODERATE TO STRONG ONSHORE FLOW AND NEAR NEW MOON...WENT
WITH HIGH RISK OF RIP CURRENTS FOR TODAY THROUGH MONDAY.

LONG TERM (MONDAY NIGHT THROUGH SATURDAY)...MID/UPPER LEVEL RIDGING
IS PROG TO STRENGTHEN ACROSS THE CWA FOR MID WEEK...THOUGH LATEST
RUNS OF THE ECMWF HAVE BACKED OFF A BIT ON NORTHWARD BUILDING OF
RIDGE. DRIER AIR AT H85 IS ALSO PROG TO BUILD IN FROM THE WESTERN
GULF FOR MID WEEK AND THE COMBINATION OF SAID FEATURES SHOULD RESULT
IN VERY LOW PRECIP CHANCES FOR EASTERN AREAS BOTH WED/THU. BEST
CONVECTIVE CHANCES FOR WESTERN AREAS MID WEEK WILL BE ALONG THE RIO
GRANDE WHERE THE DEEPEST MOISTURE WILL BE LOCATED AND WHERE
CONVECTIVE TEMPS HAVE A BETTER CHANCE OF BEING REACHED. RIDGING
BEGINS TO DAMPEN BY LATE IN THE WEEK AS A STRONG MID/UPPER TROUGH
SWINGS INTO THE PLAINS RESULTING IN A RETURN TO A POTENTIAL WET
WEATHER PATTERN FOR SOUTH TEXAS BY LATE IN THE EXTENDED PERIOD AS A
SURFACE FRONT TRIES TO WORK SOUTH INTO CENTRAL TEXAS. TEMPERATURES
THROUGH THE WEEK ARE PROG TO BECOME INCREASINGLY MORE SUMMERLIKE
WITH HIGHS IN THE 90S...LOWS IN THE 70S...ALONG WIT HUMID CONDITIONS.

&&

.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI    77  87  77  88  76  /  20  10  10  10  10
VICTORIA          76  87  75  89  74  /  20  20  10  10  10
LAREDO            76  94  76  95  76  /  40  20  20  10  10
ALICE             76  90  75  93  74  /  20  20  10  10  10
ROCKPORT          78  86  78  86  78  /  20  10  10  10  10
COTULLA           74  90  75  92  74  /  40  40  20  10  10
KINGSVILLE        77  89  76  90  76  /  20  10  10  10  10
NAVY CORPUS       78  86  77  86  77  /  10  10  10  10  10

&&

.CRP WATCHES/WARNINGS/ADVISORIES...
TX...HIGH RIP CURRENT RISK THROUGH MONDAY EVENING FOR THE FOLLOWING
     ZONES: ARANSAS...CALHOUN...KLEBERG...NUECES.

GM...NONE.

&&

$$

TB/78...AVIATION




AREA FORECAST DISCUSSION...UPDATED

NWS CORPUS CHRISTI TX

 1147 AM CDT SUN MAY 17 2015

.DISCUSSION...EARLIER MCS CONTINUES TO WEAKEN AS EVIDENT WITH
CLOUD TOPS WARMING OVER THE NORTHERN AREAS. LAST OF THE ACTIVITY
FOR NOW REMAINS OVER THE VICTORIA CROSSROADS WHERE SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS ARE ONGOING. CONVECTION SHOULD
PUSH OFF TO THE EAST AND NORTHEAST INTO THE EARLY AFTERNOON. MAIN
REASON FOR THE UPDATE WAS FRESHEN UP THE FORECAST BASED ON LATEST
TRENDS AND EXPIRE SCA AS WINDS HAVE FALLEN BELOW 20 KNOTS .

ATTENTION WILL THEN WILL TURN TO OUT WEST LATER ON THIS EVENING.
LATEST SPC MESOANALYSIS INDICATES INCREASING INSTABILITY BY LATE
THIS AFTERNOON WITH MLCAPES AOA 3500 J/KG. OUTFLOW FROM EARLIER
CONVECTION MAY FOCUS REDEVELOPMENT OF SHOWERS AND THUNDERSTORMS.
HRRR HAS BEEN HINTING AT THIS FOR THE LAST SEVERAL RUNS WITH
CONVECTION MOVING NORTHWARD OUT OF DEEP SOUTH TEXAS. CONDITIONAL
RISK OF STRONG TO SEVERE THUNDERSTORMS EXISTS IF CONVECTION DOES
INDEED DEVELOP. ALSO...HEAVY RAIN AND LOCALIZED FLOODING WILL BE A
CONCERN WITH SOILS SATURATED FROM RECENT RAINS.

&&

.PREV DISCUSSION... /ISSUED 645 AM CDT SUN MAY 17 2015/

DISCUSSION...STORMS HAVE BUILT BACK ALL THE WAY TO EAGLE PASS BUT
THE OVERALL PROGRESSION OF THE LINE CONTINUES TO SHOW EAST-SOUTHEAST
MOVEMENT. CURRENT 12Z SOUNDING AT CRP SHOWS A DRY LAYER BETWEEN
850-700 MB LAYER. LATEST HRRR AND RAP ALONG WITH 06Z NAM STILL
SHOW THAT STORMS SHOULD SHOW WEAKENING TREND AS THEY REACH SOUTH
TEXAS AND ENCOUNTER NEGATIVE THETA-E ADVECTION OVER THE COASTAL
PLAINS. SEE AVIATION SECTION FOR 12Z TAFS.

AVIATION...LOW LEVEL FLOW OF 30-35 KNOTS HAS LIMITED FOG
POTENTIAL OVER INLAND AREAS. MVFR CIGS ARE PREVALENT OVER THE
REGION THIS MORNING. MESOSCALE CONVECTIVE SYSTEM MOVING OUT OF
THE HILL COUNTRY IS EXPECTED TO WEAKEN AS IT MOVES TOWARD
SOUTH TEXAS. BUT STORMS SHOULD PERSIST AND REACH THE NORTHERN
COUNTIES BETWEEN 13-15Z. MENTIONED VCTS AT ALI BUT KEPT THE
MENTION OF CONVECTION OUT OF CRP TAFS. OUTFLOW BOUNDARY AND
DEEPER MOISTURE MAY LEAD TO ANOTHER ROUND OF CONVECTION OVER
THE BRUSH COUNTRY THAT COULD AFFECT LRD LATE THIS AFTERNOON
AND EVENING. MVFR CIGS WILL LIFT BY LATE MORNING WITH VFR
CONDITIONS EXPECTED TO BE PREVALENT BY 18Z. MVFR CIGS WILL
MOVE BACK INTO THE COASTAL PLAINS BY 00Z MONDAY AND BE
PREVALENT OVER ALL OF THE REGION BY 06Z.

PREV DISCUSSION... /ISSUED 433 AM CDT SUN MAY 17 2015/

SHORT TERM (TODAY THROUGH MONDAY)...ANOTHER MORNING WITH A
DILEMMA WITH REGARDS TO AN UPSTREAM MESOSCALE CONVECTIVE SYSTEM.
ENVIRONMENT FOR SUSTAINING MCS NOT AS GOOD AS FRIDAY. GOES SOUNDER
IMAGE OF PRECIPITABLE WATER SHOWS DRIER AIR OVER THE NORTHWEST
GULF OF MEXICO ADVECTING NORTHWARD INTO THE REGION. CORFIDI
VECTORS INDICATE THE MCS SHOULD CONTINUE MOVING TO THE SOUTHEAST
TOWARD THE NORTHERN BRUSH COUNTRY AND VICTORIA CROSSROADS REGION
THIS MORNING. 00Z HI-RES ARW/NMM AND 03Z SREF STRONGLY INDICATED
THIS MCS WOULD REACH NORTHERN COUNTIES WHILE THE 00Z NAM/00Z TECH
WRF ALONG WITH 08Z HRRR/RAP SHOWED THE SYSTEM WOULD WEAKEN
SUBSTANTIALLY AS IT NEARED THE AREA THIS MORNING. MCS STILL LOOKS
WELL ORGANIZED AND WILL LEAN TOWARD BETTER RAIN CHANCES MAINLY FOR
THE NORTHERN COUNTIES THIS MORNING. MOST OF THE SHORT RANGE MODELS
KEPT THE HIGHER LOW LEVEL THETA-E RIDGE AXIS OVER THE BRUSH
COUNTRY FOR THIS AFTERNOON. A DECENT UPPER LEVEL JET STREAK WILL
BE MOVING ACROSS NORTHERN MEXICO NOSING INTO THE BRUSH COUNTRY
THIS AFTERNOON. COULD SEE REDEVELOPMENT OF CONVECTION ALONG LEFT
OVER BOUNDARIES THAT WILL LINGER INTO THE EVENING HOURS. HI-RES
MODELS INDICATED THERE COULD BE SOME ISOLATED POCKETS OF HEAVY
RAIN FORM OVER THE BRUSH COUNTRY LATE THIS AFTERNOON INTO THIS
EVENING. IF SCENARIO BECOMES A BIT CLEARER LATER TODAY...A FLASH
FLOOD WATCH MAY BE NEEDED FOR THE WESTERN COUNTIES. THE LOWER
THETA-E AIR MASS OVER THE NORTHWEST GULF OF MEXICO WILL MOVE
INLAND INTO THE COASTAL BEND ON MONDAY WITH THE HIGHER MOISTURE
REMAINING ALONG THE RIO GRANDE. KEPT CHANCE POPS WEST TO GHOST
10 PERCENT POPS ALONG THE COAST MONDAY.

MARINE...SCA WILL CONTINUE FOR THE EARLY MORNING HOURS. EXPECT
AS CONVECTION MOVES CLOSER TO THE REGION...GRADIENT WILL DECREASE
WITH WIND SPEEDS FALLING BELOW SCA CRITERIA. WAVE WATCH MODEL
INDICATED SWELLS WILL BE INCREASING TODAY TO 5 TO 6 FEET AND
CONTINUE INTO MONDAY WITH PERIODS OF 7 TO 8 SECONDS. WITH THE
CONTINUED MODERATE TO STRONG ONSHORE FLOW AND NEAR NEW MOON...WENT
WITH HIGH RISK OF RIP CURRENTS FOR TODAY THROUGH MONDAY.

LONG TERM (MONDAY NIGHT THROUGH SATURDAY)...MID/UPPER LEVEL RIDGING
IS PROG TO STRENGTHEN ACROSS THE CWA FOR MID WEEK...THOUGH LATEST
RUNS OF THE ECMWF HAVE BACKED OFF A BIT ON NORTHWARD BUILDING OF
RIDGE. DRIER AIR AT H85 IS ALSO PROG TO BUILD IN FROM THE WESTERN
GULF FOR MID WEEK AND THE COMBINATION OF SAID FEATURES SHOULD RESULT
IN VERY LOW PRECIP CHANCES FOR EASTERN AREAS BOTH WED/THU. BEST
CONVECTIVE CHANCES FOR WESTERN AREAS MID WEEK WILL BE ALONG THE RIO
GRANDE WHERE THE DEEPEST MOISTURE WILL BE LOCATED AND WHERE
CONVECTIVE TEMPS HAVE A BETTER CHANCE OF BEING REACHED. RIDGING
BEGINS TO DAMPEN BY LATE IN THE WEEK AS A STRONG MID/UPPER TROUGH
SWINGS INTO THE PLAINS RESULTING IN A RETURN TO A POTENTIAL WET
WEATHER PATTERN FOR SOUTH TEXAS BY LATE IN THE EXTENDED PERIOD AS A
SURFACE FRONT TRIES TO WORK SOUTH INTO CENTRAL TEXAS. TEMPERATURES
THROUGH THE WEEK ARE PROG TO BECOME INCREASINGLY MORE SUMMERLIKE
WITH HIGHS IN THE 90S...LOWS IN THE 70S...ALONG WIT HUMID CONDITIONS.

&&

.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI    87  77  87  77  88  /  20  20  10  10  10
VICTORIA          87  76  87  75  89  /  50  20  20  10  10
LAREDO            94  76  94  76  95  /  30  40  20  20  10
ALICE             91  76  90  75  93  /  30  20  20  10  10
ROCKPORT          86  78  86  78  86  /  20  20  10  10  10
COTULLA           89  74  90  75  92  /  40  40  40  20  10
KINGSVILLE        89  77  89  76  90  /  30  20  10  10  10
NAVY CORPUS       86  78  86  77  86  /  20  10  10  10  10

&&

.CRP WATCHES/WARNINGS/ADVISORIES...
TX...HIGH RIP CURRENT RISK THROUGH MONDAY EVENING FOR THE FOLLOWING
     ZONES: ARANSAS...CALHOUN...KLEBERG...NUECES.

GM...NONE.

&&

$$

TB/78...SHORT TERM



AREA FORECAST DISCUSSION...UPDATED

NWS CORPUS CHRISTI TX

 645 AM CDT SUN MAY 17 2015

.DISCUSSION...STORMS HAVE BUILT BACK ALL THE WAY TO EAGLE PASS BUT
THE OVERALL PROGRESSION OF THE LINE CONTINUES TO SHOW EAST-SOUTHEAST
MOVEMENT. CURRENT 12Z SOUNDING AT CRP SHOWS A DRY LAYER BETWEEN
850-700 MB LAYER. LATEST HRRR AND RAP ALONG WITH 06Z NAM STILL
SHOW THAT STORMS SHOULD SHOW WEAKENING TREND AS THEY REACH SOUTH
TEXAS AND ENCOUNTER NEGATIVE THETA-E ADVECTION OVER THE COASTAL
PLAINS. SEE AVIATION SECTION FOR 12Z TAFS.

&&

.AVIATION...LOW LEVEL FLOW OF 30-35 KNOTS HAS LIMITED FOG
POTENTIAL OVER INLAND AREAS. MVFR CIGS ARE PREVALENT OVER THE
REGION THIS MORNING. MESOSCALE CONVECTIVE SYSTEM MOVING OUT OF
THE HILL COUNTRY IS EXPECTED TO WEAKEN AS IT MOVES TOWARD
SOUTH TEXAS. BUT STORMS SHOULD PERSIST AND REACH THE NORTHERN
COUNTIES BETWEEN 13-15Z. MENTIONED VCTS AT ALI BUT KEPT THE
MENTION OF CONVECTION OUT OF CRP TAFS. OUTFLOW BOUNDARY AND
DEEPER MOISTURE MAY LEAD TO ANOTHER ROUND OF CONVECTION OVER
THE BRUSH COUNTRY THAT COULD AFFECT LRD LATE THIS AFTERNOON
AND EVENING. MVFR CIGS WILL LIFT BY LATE MORNING WITH VFR
CONDITIONS EXPECTED TO BE PREVALENT BY 18Z. MVFR CIGS WILL
MOVE BACK INTO THE COASTAL PLAINS BY 00Z MONDAY AND BE
PREVALENT OVER ALL OF THE REGION BY 06Z.

&&

.PREV DISCUSSION... /ISSUED 433 AM CDT SUN MAY 17 2015/

SHORT TERM (TODAY THROUGH MONDAY)...ANOTHER MORNING WITH A
DILEMMA WITH REGARDS TO AN UPSTREAM MESOSCALE CONVECTIVE SYSTEM.
ENVIRONMENT FOR SUSTAINING MCS NOT AS GOOD AS FRIDAY. GOES SOUNDER
IMAGE OF PRECIPITABLE WATER SHOWS DRIER AIR OVER THE NORTHWEST
GULF OF MEXICO ADVECTING NORTHWARD INTO THE REGION. CORFIDI
VECTORS INDICATE THE MCS SHOULD CONTINUE MOVING TO THE SOUTHEAST
TOWARD THE NORTHERN BRUSH COUNTRY AND VICTORIA CROSSROADS REGION
THIS MORNING. 00Z HI-RES ARW/NMM AND 03Z SREF STRONGLY INDICATED
THIS MCS WOULD REACH NORTHERN COUNTIES WHILE THE 00Z NAM/00Z TECH
WRF ALONG WITH 08Z HRRR/RAP SHOWED THE SYSTEM WOULD WEAKEN
SUBSTANTIALLY AS IT NEARED THE AREA THIS MORNING. MCS STILL LOOKS
WELL ORGANIZED AND WILL LEAN TOWARD BETTER RAIN CHANCES MAINLY FOR
THE NORTHERN COUNTIES THIS MORNING. MOST OF THE SHORT RANGE MODELS
KEPT THE HIGHER LOW LEVEL THETA-E RIDGE AXIS OVER THE BRUSH
COUNTRY FOR THIS AFTERNOON. A DECENT UPPER LEVEL JET STREAK WILL
BE MOVING ACROSS NORTHERN MEXICO NOSING INTO THE BRUSH COUNTRY
THIS AFTERNOON. COULD SEE REDEVELOPMENT OF CONVECTION ALONG LEFT
OVER BOUNDARIES THAT WILL LINGER INTO THE EVENING HOURS. HI-RES
MODELS INDICATED THERE COULD BE SOME ISOLATED POCKETS OF HEAVY
RAIN FORM OVER THE BRUSH COUNTRY LATE THIS AFTERNOON INTO THIS
EVENING. IF SCENARIO BECOMES A BIT CLEARER LATER TODAY...A FLASH
FLOOD WATCH MAY BE NEEDED FOR THE WESTERN COUNTIES. THE LOWER
THETA-E AIR MASS OVER THE NORTHWEST GULF OF MEXICO WILL MOVE
INLAND INTO THE COASTAL BEND ON MONDAY WITH THE HIGHER MOISTURE
REMAINING ALONG THE RIO GRANDE. KEPT CHANCE POPS WEST TO GHOST
10 PERCENT POPS ALONG THE COAST MONDAY.

MARINE...SCA WILL CONTINUE FOR THE EARLY MORNING HOURS. EXPECT
AS CONVECTION MOVES CLOSER TO THE REGION...GRADIENT WILL DECREASE
WITH WIND SPEEDS FALLING BELOW SCA CRITERIA. WAVE WATCH MODEL
INDICATED SWELLS WILL BE INCREASING TODAY TO 5 TO 6 FEET AND
CONTINUE INTO MONDAY WITH PERIODS OF 7 TO 8 SECONDS. WITH THE
CONTINUED MODERATE TO STRONG ONSHORE FLOW AND NEAR NEW MOON...WENT
WITH HIGH RISK OF RIP CURRENTS FOR TODAY THROUGH MONDAY.

LONG TERM (MONDAY NIGHT THROUGH SATURDAY)...MID/UPPER LEVEL RIDGING
IS PROG TO STRENGTHEN ACROSS THE CWA FOR MID WEEK...THOUGH LATEST
RUNS OF THE ECMWF HAVE BACKED OFF A BIT ON NORTHWARD BUILDING OF
RIDGE. DRIER AIR AT H85 IS ALSO PROG TO BUILD IN FROM THE WESTERN
GULF FOR MID WEEK AND THE COMBINATION OF SAID FEATURES SHOULD RESULT
IN VERY LOW PRECIP CHANCES FOR EASTERN AREAS BOTH WED/THU. BEST
CONVECTIVE CHANCES FOR WESTERN AREAS MID WEEK WILL BE ALONG THE RIO
GRANDE WHERE THE DEEPEST MOISTURE WILL BE LOCATED AND WHERE
CONVECTIVE TEMPS HAVE A BETTER CHANCE OF BEING REACHED. RIDGING
BEGINS TO DAMPEN BY LATE IN THE WEEK AS A STRONG MID/UPPER TROUGH
SWINGS INTO THE PLAINS RESULTING IN A RETURN TO A POTENTIAL WET
WEATHER PATTERN FOR SOUTH TEXAS BY LATE IN THE EXTENDED PERIOD AS A
SURFACE FRONT TRIES TO WORK SOUTH INTO CENTRAL TEXAS. TEMPERATURES
THROUGH THE WEEK ARE PROG TO BECOME INCREASINGLY MORE SUMMERLIKE
WITH HIGHS IN THE 90S...LOWS IN THE 70S...ALONG WIT HUMID CONDITIONS.

&&

.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI    87  77  87  77  88  /  20  20  10  10  10
VICTORIA          87  76  87  75  89  /  50  20  20  10  10
LAREDO            94  76  94  76  95  /  30  40  20  20  10
ALICE             91  76  90  75  93  /  30  20  20  10  10
ROCKPORT          86  78  86  78  86  /  20  20  10  10  10
COTULLA           89  74  90  75  92  /  50  40  40  20  10
KINGSVILLE        89  77  89  76  90  /  30  20  10  10  10
NAVY CORPUS       86  78  86  77  86  /  20  10  10  10  10

&&

.CRP WATCHES/WARNINGS/ADVISORIES...
TX...HIGH RIP CURRENT RISK THROUGH MONDAY EVENING FOR THE FOLLOWING
     ZONES: ARANSAS...CALHOUN...KLEBERG...NUECES.

GM...SMALL CRAFT ADVISORY UNTIL 10 AM CDT THIS MORNING FOR THE
     FOLLOWING ZONES: COASTAL WATERS FROM BAFFIN BAY TO PORT
     ARANSAS OUT 20 NM...COASTAL WATERS FROM PORT ARANSAS TO
     MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM BAFFIN BAY
     TO PORT ARANSAS FROM 20 TO 60 NM...WATERS FROM PORT ARANSAS
     TO MATAGORDA SHIP CHANNEL FROM 20 TO 60 NM.

&&

$$

TMT/89...AVIATION



AREA FORECAST DISCUSSION

NWS HOUSTON/GALVESTON TX

 1159 PM CDT SAT MAY 16 2015

.DISCUSSION...
06Z TAF DISCUSSION IN AVIATION...

&&

.AVIATION...
OVERALL TAFS LOOK ON TRACK WITH MVFR CIGS DEVELOPING ACROSS THE
AREA. MAY GET SOME IFR FOR KCLL/KUTS/KCXO. WINDS STILL HOLDING
AROUND 10KTS ACROSS THE AREA HOWEVER. MAIN CHANGE WAS TO PUT VCTS
BACK IN TAFS SINCE GETTING STORMS IN NW HILL COUNTRY. RECENT HRRR
SEEMS TO BE PICKING UP ON THIS ACTIVITY WELL AND BRINGS IT INTO SE
TX AS A SQUALL LINE DURING THE LATE MORNING. STORMS SHOULD BE
WEAKENING BUT ENOUGH TO MENTION VCTS IN TAFS AND THEN TWEAK FROM
THERE WITH 12Z UPDATE AS STORMS EVOLVE.

39

&&

.PREV DISCUSSION... /ISSUED 930 PM CDT SAT MAY 16 2015/

DISCUSSION...
THE 00Z CRP SOUNDING SHOWED A SMALL CAP DEVELOPING OVER SE TX.
THERE WERE ISOLATED SHOWERS MOVING INLAND JUST EAST OF CHAMBERS
AND LIBERTY COUNTIES AT 920 PM. EXPECT THESE TO CONTINUE MOVING
INLAND AND STAY MAINLY EAST OF THE FORECAST AREA.

THE STORMS THAT WERE LOCATED ALONG THE DRY LINE OUT IN WEST AND
NORTH TEXAS SHOULD CONTINUE TO MOVE EASTWARD THROUGHOUT THE NIGHT.
THE 01Z RAP13 AND HRRR PLUS THE 00Z NAM12 WERE ALL PUSHING THE
AREA OF STORMS INTO THE FAR NORTHWESTERN COUNTIES BY MID MORNING
SUNDAY.

LOWERED THE POPS OVER THE NORTHERN COUNTIES TO 20 PERCENT FOR
TONIGHT. ALSO ADDED THE MENTION OF LESS THAN 20 PERCENT CHANCE FOR
SHOWERS OVER THE FAR EASTERN PORTIONS OF CHAMBERS...LIBERTY... AND
POLK COUNTIES. OTHERWISE...THE CURRENT FORECAST IS ON TRACK.

40

PREV DISCUSSION... /ISSUED 656 PM CDT SAT MAY 16 2015/

DISCUSSION...
00Z TAF DISCUSSION IN AVIATION...

AVIATION...
SOUTHERLY WINDS SHOULD REMAIN AROUND 8-12KTS TONIGHT AND THEN
INCREASE AGAIN TOMORROW TO 10-15KTS WITH GUSTS ABOVE 20KTS. CIGS
SHOULD DROP TO MVFR FOR THE MORNING HOURS. KCLL/KUTS/KCXO MAY SEE
A FEW HOURS OF IFR CIGS IN THE MORNING LIKE THIS MORNING. WILL
NEED TO MONITOR CONVECTION COMING OUT OF C TX TO SEE IF IT WILL
IMPACT TERMINALS IN THE MORNING WITH OUTFLOW BOUNDARY POSSIBLY
BEING A FOCUS FOR CONVECTION IN THE AFTERNOON. FOR NOW WILL GO
WITH VCSH AS CAPPING WILL STILL BE STRONG AND DAY TIME HEATING MAY
NOT BE ENOUGH FOR STORMS TO INITIATE.

39

PREV DISCUSSION... /ISSUED 305 PM CDT SAT MAY 16 2015/

DISCUSSION...
DAYTIME HEATING IS WORKING THE MAGIC THIS AFTERNOON WITH SCATTERED
SHOWERS AND THUNDERSTORMS NORTH OF THE 59 CORRIDOR. STORMS HAVE
BEEN SMALL AND NOT VERY IMPRESSIVE WITH WIND GUSTS OF 25 KNOTS /
VIL 25-40G/KG /STORM MOTIONS OF 23 KNOTS AND RAINFALL RATES OF
25-.75"/HOUR THANKS TO FAIRLY QUICK MOTION. THOUGH THE INSTABILITY
DOES CONTINUE TO INCREASE THE AMDAR SOUNDINGS SHOW THAT WITH PEAK
HEATING CAPE VALUES LIMITED TO 2100-2700J/KG WITH LITTLE
DIRECTIONAL SHEAR. EXPECT THAT REDEVELOPMENT WILL OCCUR THROUGH
THE REMAINING AFTERNOON HOURS PROGRESSIVELY FURTHER NORTH...THEN
WANE DURING THE EARLY EVENING HOURS. A FEW MODELS HIGHLIGHT
DEVELOPMENT WELL DOWN THE DRYLINE IN WEST TEXAS BETWEEN MAF/SJT.
IF THIS OCCURS THEN WILL NEED TO KEEP AN EYE ON THE TAIL- DRAGGERS
AS THEY MAY GET CLOSE TO THE NW CWA AFTER MIDNIGHT. HEAVY RAIN
THREAT LOOKS LOW HERE BUT NORTHWEST OF THE AREA THE THREAT SHOULD
INCREASE WHERE STORMS LINE UP AND TRAIN AS LLJ INTENSIFIES WITH
STORMS GOING MUCH OF THE NIGHT LIKELY JUST TO OUR NORTHWEST.
OVERNIGHT EXPECT ST DECK TO RETURN THE AREA AND SSE FLOW TO
CONTINUE ALBEIT SOMEWHAT LESS FORCEFULLY INLAND SO TEMPERATURES
SHOULD FALL SLOWLY GIVEN THE CLOUD COVER/WINDS.

UPPER RIDGING WILL CONTINUE TO PLAY A LARGER PART IN OUR DAILY
RAIN CHANCES AS RIDGING BUILDS INTO THE AREA 588-590DM 500MB
HEIGHTS COVER MUCH OF THE REGION SUNDAY AND EARLY MONDAY. THIS
SHOULD LEAD TO WARMER CONDITIONS AND A LITTLE MORE CAPPING. THEN
LATE MONDAY AND TUESDAY RIDGE FLATTENS AND RAIN CHANCES SHOULD
INCREASE SLIGHTLY FOR THE NORTHERN HALF OF THE AREA AS STORM TRACK
SHIFTS SLIGHTLY FURTHER SOUTH AND EAST. HIGHEST RAIN CHANCE THIS
WEEK LOOK TO BE OVER THE NORTHEAST COUNTIES ON MONDAY AND TUESDAY
AFTERNOON. FRONTAL BOUNDARY SLIPS SOUTH INTO THE NORTHEAST
PORTIONS TX/NW LA AND THIS COULD BECOME A FOCUS FOR STORMS.
HEAVIER RAINS IN THESE NORTHERN AREAS A THREAT MONDAY AND TUESDAY.
WEDNESDAY THE RIDGING RETURNS AND RAIN CHANCES AGAIN TAPER OFF.
NEXT TROUGH DROPS INTO THE DESERT SW FRIDAY/SATURDAY WHICH MAY SET
THE STAGE FOR SLIGHTLY HIGHER RAIN CHANCES IN OUR WESTERN ZONES
BUT EXTENDED GUIDANCE SHOWING THE RIDGING OVER THE GULF POSSIBLY
EXERTING ENOUGH INFLUENCE TO LIMIT RAIN CHANCES OVER AT LEAST THE
SOUTHEASTERN HALF OF THE AREA.

TEMPERATURES SHOULD RUN 2 TO 4 DEGREES WARMER THAN NORMAL DURING
THE DAY AND 4 TO 9 DEGREES WARMER ON MINS WITH THE PERSISTENT
MOIST GULF RETURN.
45

MARINE...
AS A STRONG STORM SYSTEM DEEPENS OVER THE CENTRAL PLAINS...
A TIGHTENING PRESSURE GRADIENT WILL HELP KEEP ELEVATED WINDS
AND SEAS ACROSS OUR COASTAL WATERS THROUGH SUNDAY. CAUTION FLAGS
ARE IN EFFECT...AND ADVISORIES MIGHT BE NEEDED. WINDS AND SEAS
ARE STILL EXPECTED TO DECREASE BEGINNING ON MONDAY...AND MAINLY
MODERATE ONSHORE WINDS ARE ANTICIPATED FOR MUCH OF THE WEEK.
42

&&

.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL)      75  87  74  87  72 /  20  30  20  30  20
HOUSTON (IAH)              77  88  75  88  73 /  20  20  20  30  10
GALVESTON (GLS)            78  85  79  85  76 /  10  20  20  20  10

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 6 AM CDT SUNDAY FOR
     THE FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY...WATERS
     FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...
     WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM.

     SMALL CRAFT SHOULD EXERCISE CAUTION THROUGH SUNDAY EVENING FOR
     THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA
     SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM HIGH ISLAND TO
     FREEPORT 20 TO 60 NM.

&&

$$

DISCUSSION...40
AVIATION/MARINE...39



FOR FREQUENTLY ASKED QUESTIONS ABOUT THE AREA FORECAST DISCUSSION

VISIT...

 HTTP://WEATHER.GOV/SALTLAKECITY/GENERAL/AFD_FAQS.PHP (ALL LOWER CASE)




AREA FORECAST DISCUSSION

NWS BLACKSBURG VA

 941 PM EDT MON MAY 18 2015

.SYNOPSIS...
A COLD FRONT WILL MOVE EAST ACROSS THE OHIO VALLEY OVERNIGHT...
THEN CROSS THE MID ATLANTIC REGION TUESDAY. SOME ADDITIONAL SHOWERS
ARE POSSIBLE IN THE WEST OVERNIGHT...WITH SHOWERS AND A FEW STORMS
POSSIBLE ON TUESDAY...ESPECIALLY ACROSS THE SOUTHEAST PART OF THE
REGION. ONCE THE FRONT PASSES EAST OF THE AREA TUESDAY...COOLER...DRIER
AIR WILL FILTER INTO THE REGION FOR MID WEEK.

&&

.NEAR TERM /THROUGH TUESDAY/...
AS OF 935 PM EDT MONDAY...

MUCH OF THE SHOWER AND THUNDERSTORM ACTIVITY HAS ENDED ACROSS THE
REGION. WHAT REMAINS IS MAINLY ACROSS BUCKINGHAM COUNTY VA...BUT
THERE TOO...THE PRECIPITATION WILL CONTINUE TO DISSIPATE. ISOLATED
TO SCATTERED SHOWERS ARE EXPECTED TO RETURN TO WESTERN PARTS OF
THE AREA AFTER MIDNIGHT IN ADVANCE OF AN APPROACHING COLD FRONT.
HAVE MADE MINOR ADJUSTMENTS UPWARD TO THE EXPECTED LOW
TEMPERATURES ACROSS THE EASTERN PORTIONS OF THE AREA. PATCHY FOG
IS EXPECTED TO DEVELOP OVERNIGHT...WITH AREAS THAT RECEIVED RAIN
TODAY...RIVER VALLEYS AND MOUNTAIN VALLEYS THE MOST LIKELY AREAS
TO EXPERIENCE SOME. NO OTHER NOTABLE CHANGES WERE MADE AT THIS
TIME.

AS OF 640 PM EDT MONDAY...

NO MAJOR CHANGES TO THE FORECAST AS WE HEAD INTO THE EVENING
HOURS. WE STILL EXPECT SCATTERED SHOWERS AND SOME STORMS ACROSS
MUCH OF THE REGION. WHAT DID CHANGE WAS THE FOCUS FOR WHERE THE
BEST CHANCES WOULD BE IN THE NEXT COUPLE OF HOURS BASED UPON WHERE
THE GREATEST CONCENTRATION IS CURRENTLY LOCATED...FROM FRANKLIN
COUNTY VA SOUTHWEST TO AROUND PILOT MOUNTAIN IN NORTH
CAROLINA...AND WEST TO THE GRAYSON HIGHLANDS OF SOUTHWEST
VIRGINIA. ALSO...ANOTHER GENEROUS REGION OF PRECIPITATION WAS
MOVING THROUGH ROCKBRIDGE COUNTY VA...AND THERE WAS ANOTHER ONE
APPROACHING WESTERN GREENBRIER COUNTY AND SUMMERS COUNTY IN
SOUTHEAST WEST VIRGINIA. AS WE PROGRESS INTO THE LATE EVENING AND
TOWARDS MIDNIGHT....FORECAST CHANGES WERE A LITTLE MORE EXPANSIVE.
BASED UPON THE LATEST HRRR AND RNK WRF. THE FORECAST WILL NOW
REFLECT LITTLE OR NO COVERAGE OF PRECIPITATION OUTSIDE SOUTHEAST
WEST VIRGINIA AND NEIGHBORING PORTIONS OF SOUTHWEST VIRGINIA ONCE
WE REACH THAT TIME TONIGHT.

AS OF 330 PM EDT MONDAY...

PWATS 2-3 STANDARD DEVIATIONS ABOVE NORMAL WILL HELP FUEL
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS THIS EVENING.
THE AIRMASS IS UNSEASONABLY JUICY BUT LACK OF ANY GOOD DYNAMICS
SHOULD KEEP ACTIVITY UNORGANIZED. NEVER THE LESS...SLOW MOVEMENT
WILL YIELD HEAVY DOWNPOURS FOR ANY PASSING SHOWER/STORM.

FORECAST AREA REMAINS UNDERNEATH A VERY SHARP UPPER LEVEL
RIDGE...WHICH IS PROMOTING VERY LIGHT STEERING WINDS...0-8KM MEAN
WIND OF ONLY 11 KTS...FROM 290 DEGREES. THIS UPPER RIDGE IS
EXPECTED TO WEAKEN AS WE TRANSITION THROUGH THE NEXT 12-18
HOURS...AS LOW PRESSURE MOVES ACROSS THE GREAT LAKES AND INTO
ONTARIO CANADA. AT THE SURFACE...A COLD FRONT WILL TRAIL SOUTH
FROM THE LOW...CROSSING THE OHIO VALLEY TONIGHT. AS THE FRONT
APPROACHES...IT WILL FOCUS THE DEEPER MOISTURE FROM THE OH/TN
VALLEYS INTO THE WEST SIDE OF THE APPALACHIANS. THIS SQUEEZE PLAY
OF DEEPER MOISTURE IN ADDITION TO LINGERING INSTABILITY OVER THE
MOUNTAINS WILL RESULT IN GOOD COVERAGE OF SHOWER ACTIVITY THROUGH
THIS EVENING.

COVERAGE AND INTENSITY OF SHOWER AND THUNDERSTORM ACTIVITY WILL
DECREASE WITH THE LOSS OF DAYTIME HEATING. HOWEVER...WITH THE
COLD FRONT CONTINUING ITS APPROACH OVERNIGHT...SHOWER THREAT WILL
NOT SUBSIDE ALTOGETHER. MOISTURE TRANSPORT AND CONVERGENCE PER
SOUTHWEST WIND FLOW AHEAD OF THE FRONT WILL CONTINUE TO GENERATE
ACTIVITY INTO THE LATE NIGHT.

SURFACE FRONT IS EXPECTED TO REACH THE WESTERN SLOPES OF THE
APPALACHIANS BY DAYBREAK TUESDAY...THEN MOVE OVER AND EAST OF THE
MTNS MID-DAY...CLEARING THE CWA BY TUESDAY EVENING. WILL MAINTAIN
THREAT FOR SHOWERS UNTIL THE PASSAGE OF THE FRONT...FOLLOWED BY
CLEARING AND DRYING WITH FROPA.

MET/MAV TEMPERATURE GUIDANCE LOOKS GOOD...AND USED A BLEND FOR
TONIGHT`S LOWS AND TUESDAYS HIGHS...READINGS REMAINING QUITE MILD
TONIGHT...AOA 60 FOR LOWS...FOLLOWED BY ANOTHER WARM DAY TUESDAY
WITH HIGHS RANGING IN THE 70S MTNS TO THE 80S IN THE LOWER
ELEVATIONS.

ANY SIGNIFICANT COOLING/DRYING WILL NOT TAKE PLACE UNTIL WE CHANGE
AIRMASSES LATER TUESDAY...BECOMING NOTICEABLE ONCE THE SUN GOES
DOWN TUESDAY EVENING.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
AS OF 300 PM EDT MONDAY...

ANY LINGERING CONVECTION IN THE FAR SOUTHEAST PORTIONS OF FORECAST
AREA WILL TAPER OFF BY 06Z WEDNESDAY. LOW TEMPERATURES TUESDAY NIGHT
WILL RANGE FROM THE UPPER 40S IN THE NORTHWEST MOUNTAINS TO
THE LOWER 60S IN THE PIEDMONT.

HIGH PRESSURE IN THE MIDWEST WILL RIDGE SOUTHEAST INTO OUR AREA FOR
WEDNESDAY PROVIDING A BREAK FROM THE ACTIVE CONVECTION. THE COOLER
HIGH TEMPERATURES ON WEDNESDAY WILL ALSO BE A WELCOME CHANGE WITH
READINGS FROM THE LOWER 60S IN THE NORTHWEST MOUNTAINS TO THE MID
80S IN THE PIEDMONT. WITH A WEAK SHORTWAVE ROTATING EAST ACROSS THE
REGION WEDNESDAY NIGHT...ALLOW FOR SOME LIGHT POPS IN THE WEST.
LOW TEMPERATURES WEDNESDAY NIGHT WILL VARY FROM THE UPPER 40S IN
THE WEST TO THE UPPER 50S IN THE EAST.

THURSDAYS FORECAST REMAINS A CHALLENGE WITH THE LATEST MODEL RUNS
ALL DEPICT A STRONGER SHORTWAVE TRACKING ACROSS THE AREA...BUT WITH
WIDELY VARYING DEGREES OF INTENSITY AND RESULTANT
MOISTURE/PRECIPITATION. WITH CAUTION...ELECTED TO USE A BLEND OF
SUPERBLEND AND HPCGUIDE WITH SCATTERED POPS FOR THURSDAY. HIGH
TEMPERATURES THURSDAY WILL WARM TO AROUND 60 DEGREES IN THE
NORTHWEST TO AROUND 80 DEGREES ALONG THE SOUTHERN BLUE RIDGE.

SHORTWAVE WILL EXIT TO THE SOUTHEAST THURSDAY NIGHT AS SFC HIGH
PRESSURE SLIDES FROM THE PLAINS TO THE GREAT LAKES. OVERALL...THE
AIRMASS APPEARS TO BE TOO STABLE AND DRY IN THE LOWER LEVELS TO
SUPPORT MUCH THUNDER WITH THIS EVENT. HOWEVER...A NOSE OF
INSTABILITY SUPPORT ISOLATED THUNDERSTORM ACROSS SOUTHERN PORTIONS
OF FORECAST AREA. DIURNAL CONVECTION TAPERS OFF QUICKLY THURSDAY
NIGHT. LOW TEMPERATURES THURSDAY NIGHT WILL GENERALLY VARY FROM THE
UPPER 40S IN THE MOUNTAINS TO THE UPPER 50S IN THE PIEDMONT.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 300 PM EDT MONDAY...

MOISTURE...WARMTH...AND HUMIDITY ARE POISED TO RETURN BY EARLY NEXT
WEEK AS YET ANOTHER DEEP UPPER LOW BUILDS INTO THE SOUTHWEST UNITED
STATE...THE NORTHEAST TROUGH PUSHES EASTWARD INTO THE NORTHERN
ATLANTIC...AND AN ELONGATED RIDGE BETWEEN THESE TWO FEATURES DRIFTS
INTO OUR REGION. HIGH TEMPERATURES FRIDAY WARM INTO THE MID 60S IN
THE MOUNTAINS TO THE MID 70S IN THE PIEDMONT. LOW TEMPERATURES WILL
DROP INTO THE MID 40S TO THE 50S IN GENERAL.

ON SATURDAY...CANADIAN HIGH PRESSURE SHIFTS OFF THE MID-ATLANTIC
COAST...AS FRONTAL BOUNDARY IS CENTRAL U.S. LIFTS NORTHEAST. KEPT
SATURDAY DRY...WITH HIGH TEMPERATURES RANGING FROM THE MID 60S IN
THE NORTHWEST MOUNTAINS TO THE UPPER 70S IN THE PIEDMONT.

AS THE HIGH CENTER MOVES EAST...AN EAST TO SOUTHEAST RETURN FLOW ON
THE BACKSIDE MAY DEVELOP A WEDGE ACROSS THE REGION OVER THE WEEKEND.
WITH THE POTENTIAL OF OVERRUNNING PRECIPITATION DEVELOPING FROM THE
WEST. ADDED A SLIGHT CHANCE OF SHOWERS IN THE NORTHWEST MOUNTAINS OF
NORTH CAROLINA.  MODERATED LOW TEMPERATURES SATURDAY NIGHT WITH
VALUES MAINLY IN THE 50S...WITH INCREASED CLOUD COVER. SCATTERED
SHOWERS CONTINUED ON SUNDAY WITH THE BEST CHANCES IN THE NORTHWEST.

THE UPPER RIDGE WILL SHIFT SOUTHEAST BY MONDAY...ALLOWING AN ACTIVE
BAROCLINIC ZONE TO SHIFT SOUTH AND EAST INTO THE REGION FROM THE
OH/TN VALLEY. CONTINUED THE POTENTIAL FOR SCATTERED CONVECTION ON
TUESDAY.

&&

.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
AS OF 755 PM EDT MONDAY...

LOCAL NWS RADAR SHOWERS SCATTERED SHOWERS AND THUNDERSTORMS ALIGN
THE BLUE RIDGE AND OVER THE FOOTHILLS EAST OF THE MOUNTAINS AT THE
00Z START OF THE TAF PERIOD. THUNDERSTORMS WILL BE OVER THE KLYH
AND KDAN AIRPORTS UNTIL 01Z/9PM. WITH THE LOSS OF HEATING THE
COVERAGE OF SHOWERS AND THUNDERSTORMS WILL DIMINISH BUT
PRECIPITATION WILL NOT COMPLETELY DRY OUT EVEN OVERNIGHT.
HOWEVER...THE PROBABILITY WAS NOT HIGH ENOUGH TO INCLUDE IN THE
TAFS AT THIS TIME.

NORTHWEST TO SOUTHWEST WINDS AT THE SURFACE AND THROUGH MID LEVEL
OF THE ATMOSPHERE WILL MAINTAIN HIGH AMOUNTS OF MOISTURE IN THE
REGION AND THE UPSLOPE FLOW WILL RESULT IN MVFR CLOUD AND FOG IN
THE MOUNTAINS AFTER MIDNIGHT. HIGH CONFIDENCE IN THE FORMATION OF
THE CLOUDS AND LOWER CONFIDENCE IN THE FORMATION OF FOG.

ANY LOW CIG/VSBY ELEMENTS SHOULD QUICKLY IMPROVE AFTER 13Z/9AM
TUESDAY WITH RETURN OF VFR FOR THE AFTERNOON. SURFACE FRONT WILL
PASS THROUGH ALL TERMINALS TUESDAY WITH SKIES CLEARING AND WINDS
BECOMING NORTHWEST 6 TO 12 KTS. GUSTS UP RO 25 KNOTS ARE POSSIBLE
IN THE MOUNTAINS.

EXTENDED AVIATION DISCUSSION...

DRIER/COOLER CONDITIONS ARE EXPECTED TUESDAY NIGHT AND WEDNESDAY.
AN UPPER DISTURBANCE WILL LIKELY BRING SOME MVFR CIGS AND -SHRA
BACK INTO THE AREA THU...MOVING OUT FRIDAY WITH VFR CONDITIONS
RETURNING FRI-SAT.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...DS/PM
NEAR TERM...DS/PM
SHORT TERM...KK
LONG TERM...KK
AVIATION...AMS/PM




AREA FORECAST DISCUSSION

NWS BLACKSBURG VA

 800 PM EDT MON MAY 18 2015

.SYNOPSIS...
A COLD FRONT EXTENDS FROM MICHIGAN TO SOUTHERN MISSOURI. THIS
FRONT WILL MOVE EAST ACROSS THE OHIO VALLEY OVERNIGHT...CROSSING
THE MID ATLANTIC REGION TUESDAY. MOIST SOUTHERLY FLOW AHEAD OF THE
FRONT WILL HELP FUEL SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS.
ONCE THE FRONT PASSES EAST OF THE AREA TUESDAY...COOLER...DRIER
AIR WILL FILTER INTO THE REGION FOR MID WEEK.

&&

.NEAR TERM /THROUGH TUESDAY/...
AS OF 640 PM EDT MONDAY...

NO MAJOR CHANGES TO THE FORECAST AS WE HEAD INTO THE EVENING
HOURS. WE STILL EXPECT SCATTERED SHOWERS AND SOME STORMS ACROSS
MUCH OF THE REGION. WHAT DID CHANGE WAS THE FOCUS FOR WHERE THE
BEST CHANCES WOULD BE IN THE NEXT COUPLE OF HOURS BASED UPON WHERE
THE GREATEST CONCENTRATION IS CURRENTLY LOCATED...FROM FRANKLIN
COUNTY VA SOUTHWEST TO AROUND PILOT MOUNTAIN IN NORTH
CAROLINA...AND WEST TO THE GRAYSON HIGHLANDS OF SOUTHWEST
VIRGINIA. ALSO...ANOTHER GENEROUS REGION OF PRECIPITATION WAS
MOVING THROUGH ROCKBRIDGE COUNTY VA...AND THERE WAS ANOTHER ONE
APPROACHING WESTERN GREENBRIER COUNTY AND SUMMERS COUNTY IN
SOUTHEAST WEST VIRGINIA. AS WE PROGRESS INTO THE LATE EVENING AND
TOWARDS MIDNIGHT....FORECAST CHANGES WERE A LITTLE MORE EXPANSIVE.
BASED UPON THE LATEST HRRR AND RNK WRF. THE FORECAST WILL NOW
REFLECT LITTLE OR NO COVERAGE OF PRECIPITATION OUTSIDE SOUTHEAST
WEST VIRGINIA AND NEIGHBORING PORTIONS OF SOUTHWEST VIRGINIA ONCE
WE REACH THAT TIME TONIGHT.

AS OF 330 PM EDT MONDAY...

PWATS 2-3 STANDARD DEVIATIONS ABOVE NORMAL WILL HELP FUEL
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS THIS EVENING.
THE AIRMASS IS UNSEASONABLY JUICY BUT LACK OF ANY GOOD DYNAMICS
SHOULD KEEP ACTIVITY UNORGANIZED. NEVER THE LESS...SLOW MOVEMENT
WILL YIELD HEAVY DOWNPOURS FOR ANY PASSING SHOWER/STORM.

FORECAST AREA REMAINS UNDERNEATH A VERY SHARP UPPER LEVEL
RIDGE...WHICH IS PROMOTING VERY LIGHT STEERING WINDS...0-8KM MEAN
WIND OF ONLY 11 KTS...FROM 290 DEGREES. THIS UPPER RIDGE IS
EXPECTED TO WEAKEN AS WE TRANSITION THROUGH THE NEXT 12-18
HOURS...AS LOW PRESSURE MOVES ACROSS THE GREAT LAKES AND INTO
ONTARIO CANADA. AT THE SURFACE...A COLD FRONT WILL TRAIL SOUTH
FROM THE LOW...CROSSING THE OHIO VALLEY TONIGHT. AS THE FRONT
APPROACHES...IT WILL FOCUS THE DEEPER MOISTURE FROM THE OH/TN
VALLEYS INTO THE WEST SIDE OF THE APPALACHIANS. THIS SQUEEZE PLAY
OF DEEPER MOISTURE IN ADDITION TO LINGERING INSTABILITY OVER THE
MOUNTAINS WILL RESULT IN GOOD COVERAGE OF SHOWER ACTIVITY THROUGH
THIS EVENING.

COVERAGE AND INTENSITY OF SHOWER AND THUNDERSTORM ACTIVITY WILL
DECREASE WITH THE LOSS OF DAYTIME HEATING. HOWEVER...WITH THE
COLD FRONT CONTINUING ITS APPROACH OVERNIGHT...SHOWER THREAT WILL
NOT SUBSIDE ALTOGETHER. MOISTURE TRANSPORT AND CONVERGENCE PER
SOUTHWEST WIND FLOW AHEAD OF THE FRONT WILL CONTINUE TO GENERATE
ACTIVITY INTO THE LATE NIGHT.

SURFACE FRONT IS EXPECTED TO REACH THE WESTERN SLOPES OF THE
APPALACHIANS BY DAYBREAK TUESDAY...THEN MOVE OVER AND EAST OF THE
MTNS MID-DAY...CLEARING THE CWA BY TUESDAY EVENING. WILL MAINTAIN
THREAT FOR SHOWERS UNTIL THE PASSAGE OF THE FRONT...FOLLOWED BY
CLEARING AND DRYING WITH FROPA.

MET/MAV TEMPERATURE GUIDANCE LOOKS GOOD...AND USED A BLEND FOR
TONIGHT`S LOWS AND TUESDAYS HIGHS...READINGS REMAINING QUITE MILD
TONIGHT...AOA 60 FOR LOWS...FOLLOWED BY ANOTHER WARM DAY TUESDAY
WITH HIGHS RANGING IN THE 70S MTNS TO THE 80S IN THE LOWER
ELEVATIONS.

ANY SIGNIFICANT COOLING/DRYING WILL NOT TAKE PLACE UNTIL WE CHANGE
AIRMASSES LATER TUESDAY...BECOMING NOTICEABLE ONCE THE SUN GOES
DOWN TUESDAY EVENING.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
AS OF 300 PM EDT MONDAY...

ANY LINGERING CONVECTION IN THE FAR SOUTHEAST PORTIONS OF FORECAST
AREA WILL TAPER OFF BY 06Z WEDNESDAY. LOW TEMPERATURES TUESDAY NIGHT
WILL RANGE FROM THE UPPER 40S IN THE NORTHWEST MOUNTAINS TO
THE LOWER 60S IN THE PIEDMONT.

HIGH PRESSURE IN THE MIDWEST WILL RIDGE SOUTHEAST INTO OUR AREA FOR
WEDNESDAY PROVIDING A BREAK FROM THE ACTIVE CONVECTION. THE COOLER
HIGH TEMPERATURES ON WEDNESDAY WILL ALSO BE A WELCOME CHANGE WITH
READINGS FROM THE LOWER 60S IN THE NORTHWEST MOUNTAINS TO THE MID
80S IN THE PIEDMONT. WITH A WEAK SHORTWAVE ROTATING EAST ACROSS THE
REGION WEDNESDAY NIGHT...ALLOW FOR SOME LIGHT POPS IN THE WEST.
LOW TEMPERATURES WEDNESDAY NIGHT WILL VARY FROM THE UPPER 40S IN
THE WEST TO THE UPPER 50S IN THE EAST.

THURSDAYS FORECAST REMAINS A CHALLENGE WITH THE LATEST MODEL RUNS
ALL DEPICT A STRONGER SHORTWAVE TRACKING ACROSS THE AREA...BUT WITH
WIDELY VARYING DEGREES OF INTENSITY AND RESULTANT
MOISTURE/PRECIPITATION. WITH CAUTION...ELECTED TO USE A BLEND OF
SUPERBLEND AND HPCGUIDE WITH SCATTERED POPS FOR THURSDAY. HIGH
TEMPERATURES THURSDAY WILL WARM TO AROUND 60 DEGREES IN THE
NORTHWEST TO AROUND 80 DEGREES ALONG THE SOUTHERN BLUE RIDGE.

SHORTWAVE WILL EXIT TO THE SOUTHEAST THURSDAY NIGHT AS SFC HIGH
PRESSURE SLIDES FROM THE PLAINS TO THE GREAT LAKES. OVERALL...THE
AIRMASS APPEARS TO BE TOO STABLE AND DRY IN THE LOWER LEVELS TO
SUPPORT MUCH THUNDER WITH THIS EVENT. HOWEVER...A NOSE OF
INSTABILITY SUPPORT ISOLATED THUNDERSTORM ACROSS SOUTHERN PORTIONS
OF FORECAST AREA. DIURNAL CONVECTION TAPERS OFF QUICKLY THURSDAY
NIGHT. LOW TEMPERATURES THURSDAY NIGHT WILL GENERALLY VARY FROM THE
UPPER 40S IN THE MOUNTAINS TO THE UPPER 50S IN THE PIEDMONT.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 300 PM EDT MONDAY...

MOISTURE...WARMTH...AND HUMIDITY ARE POISED TO RETURN BY EARLY NEXT
WEEK AS YET ANOTHER DEEP UPPER LOW BUILDS INTO THE SOUTHWEST UNITED
STATE...THE NORTHEAST TROUGH PUSHES EASTWARD INTO THE NORTHERN
ATLANTIC...AND AN ELONGATED RIDGE BETWEEN THESE TWO FEATURES DRIFTS
INTO OUR REGION. HIGH TEMPERATURES FRIDAY WARM INTO THE MID 60S IN
THE MOUNTAINS TO THE MID 70S IN THE PIEDMONT. LOW TEMPERATURES WILL
DROP INTO THE MID 40S TO THE 50S IN GENERAL.

ON SATURDAY...CANADIAN HIGH PRESSURE SHIFTS OFF THE MID-ATLANTIC
COAST...AS FRONTAL BOUNDARY IS CENTRAL U.S. LIFTS NORTHEAST. KEPT
SATURDAY DRY...WITH HIGH TEMPERATURES RANGING FROM THE MID 60S IN
THE NORTHWEST MOUNTAINS TO THE UPPER 70S IN THE PIEDMONT.

AS THE HIGH CENTER MOVES EAST...AN EAST TO SOUTHEAST RETURN FLOW ON
THE BACKSIDE MAY DEVELOP A WEDGE ACROSS THE REGION OVER THE WEEKEND.
WITH THE POTENTIAL OF OVERRUNNING PRECIPITATION DEVELOPING FROM THE
WEST. ADDED A SLIGHT CHANCE OF SHOWERS IN THE NORTHWEST MOUNTAINS OF
NORTH CAROLINA.  MODERATED LOW TEMPERATURES SATURDAY NIGHT WITH
VALUES MAINLY IN THE 50S...WITH INCREASED CLOUD COVER. SCATTERED
SHOWERS CONTINUED ON SUNDAY WITH THE BEST CHANCES IN THE NORTHWEST.

THE UPPER RIDGE WILL SHIFT SOUTHEAST BY MONDAY...ALLOWING AN ACTIVE
BAROCLINIC ZONE TO SHIFT SOUTH AND EAST INTO THE REGION FROM THE
OH/TN VALLEY. CONTINUED THE POTENTIAL FOR SCATTERED CONVECTION ON
TUESDAY.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
AS OF 755 PM EDT MONDAY...

LOCAL NWS RADAR SHOWERS SCATTERED SHOWERS AND THUNDERSTORMS ALIGN
THE BLUE RIDGE AND OVER THE FOOTHILLS EAST OF THE MOUNTAINS AT THE
00Z START OF THE TAF PERIOD. THUNDERSTORMS WILL BE OVER THE KLYH
AND KDAN AIRPORTS UNTIL 01Z/9PM. WITH THE LOSS OF HEATING THE
COVERAGE OF SHOWERS AND THUNDERSTORMS WILL DIMINISH BUT
PRECIPITATION WILL NOT COMPLETELY DRY OUT EVEN OVERNIGHT.
HOWEVER...THE PROBABILITY WAS NOT HIGH ENOUGH TO INCLUDE IN THE
TAFS AT THIS TIME.

NORTHWEST TO SOUTHWEST WINDS AT THE SURFACE AND THROUGH MID LEVEL
OF THE ATMOSPHERE WILL MAINTAIN HIGH AMOUNTS OF MOISTURE IN THE
REGION AND THE UPSLOPE FLOW WILL RESULT IN MVFR CLOUD AND FOG IN
THE MOUNTAINS AFTER MIDNIGHT. HIGH CONFIDENCE IN THE FORMATION OF
THE CLOUDS AND LOWER CONFIDENCE IN THE FORMATION OF FOG.

ANY LOW CIG/VSBY ELEMENTS SHOULD QUICKLY IMPROVE AFTER 13Z/9AM
TUESDAY WITH RETURN OF VFR FOR THE AFTERNOON. SURFACE FRONT WILL
PASS THROUGH ALL TERMINALS TUESDAY WITH SKIES CLEARING AND WINDS
BECOMING NORTHWEST 6 TO 12 KTS. GUSTS UP RO 25 KNOTS ARE POSSIBLE
IN THE MOUNTAINS.

EXTENDED AVIATION DISCUSSION...

DRIER/COOLER CONDITIONS ARE EXPECTED TUESDAY NIGHT AND WEDNESDAY.
AN UPPER DISTURBANCE WILL LIKELY BRING SOME MVFR CIGS AND -SHRA
BACK INTO THE AREA THU...MOVING OUT FRIDAY WITH VFR CONDITIONS
RETURNING FRI-SAT.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...PM
NEAR TERM...DS/PM
SHORT TERM...KK
LONG TERM...KK
AVIATION...AMS/PM




AREA FORECAST DISCUSSION

NWS BLACKSBURG VA

 214 AM EDT SUN MAY 17 2015

.SYNOPSIS...
HIGH PRESSURE OFFSHORE WILL MAINTAIN A MOIST SOUTHERLY FLOW OF AIR
ACROSS THE REGION THROUGH MONDAY. A COLD FRONT WILL SLOWLY
APPROACH FROM THE WEST LATE MONDAY...MOVING THROUGH THE REGION
TUESDAY. COOLER...DRIER AIR WILL FILTER INTO THE REGION BY THE
MID PART OF NEXT WEEK BEHIND THE FRONT.

&&

.NEAR TERM /THROUGH TODAY/...
AS OF 835 PM EDT SATURDAY...

MAIN CORRIDOR OF CONVECTION REMAINS ACROSS THE FAR WESTERN THIRD
THIS EVENING IN AN AXIS OF HIGHER CAPE UNDER A WEAK CONVERGENCE
AREA ALONG THE TAIL OF ANOTHER PASSING WEAK MID LEVEL WAVE.
EVENING RNK SOUNDING SHOWING THINGS QUITE SATURATED WITH MOIST
PWATS AND WEAK VEERING OVERTOP RATHER STRONG INSTABILITY. THUS
APPEARS AT LEAST SHALLOW CONVECTION MAY CONTINUE TO LINGER A BIT
LONGER WEST AS STILL SEEING NEW DEVELOPMENT OFF OUTFLOW BANDS.
THUS KEEPING LIKELY/HIGH CHANCE POPS GOING ESPCLY VA HIGHLANDS/SE
WEST VA UNTIL JUST BEFORE MIDNIGHT. LATEST HRRR ALSO SHOWS SOME
COVERAGE OUT TO THE BLUE RIDGE IN VIRGINIA WHERE INSTABILITY YET
TO BE WORKED OVER MUCH. THEREFORE LEAVING IN SOME CHANCE POPS
FARTHER EAST INTO THE EARLY MORNING HOURS BEFORE ENOUGH
COOLING...AND LESS UPPER SUPPORT FINALLY CAUSES SHRA TO FADE. OTRW
DEGREE OF DEBRIS CLOUDS MAKING THINGS A BIT TRICKY WITH FOG
COVERAGE OVERNIGHT AS SHOULD STILL SEE RATHER WIDESPREAD
FOG/STRATUS WEST WHERE HEAVY RAIN HAS OCCURRED. ELSEWHERE APPEARS
PATCHY COVERAGE OUTSIDE OF AREAS THAT HAVE SEEN THE HEAVY
DOWNPOURS...AND MOSTLY IN THE LOW SPOTS/VALLEYS PROVIDED A BIT OF
CLEARING LATER. SOUPY ENVIRONMENT WILL ONLY ALLOW FOR GRADUAL TEMP
FALLS OVERNIGHT WITH MOST SPOTS STAYING IN THE 60S EXCEPT FOR
PERHAPS A FEW 50S NW VALLEYS.


PREVIOUS DISCUSSION AS OF 303 PM EDT SATURDAY...

SUBTROPICAL RIDGE CONTINUES FROM THE SOUTHEAST STATES INTO THE MID-
ATLANTIC REGION THIS AFTERNOON INTO SUNDAY. A SOUTHERLY FLOW OF WARM
AND HUMID AIR COMBINING WITH INSTABILITY AND WEAK SHORTWAVES THIS
THIS AFTERNOON GENERATING SCATTERED SHOWERS AND THUNDERSTORMS. CAPES
THIS AFTERNOON VARY FROM 500 TO 1K J/KG...AND LIS AROUND MINUS 1 TO
MINUS 3...WITH INCREASED PWAT ABOUT AN INCH. INTERESTING TO NOTE
OFF THE 18Z SPC MESOANALYSIS OF A 800 DOWNDRAFT CAPE LOCATED TO
OUR NORTHEAST. AS INDICATED BY SWODY1...THE BETTER DYNAMIC AND
CHANCE FOR STRONGER TO SEVERE ARE LOCATED TO OUR NORTH AND WEST.
ONE CONCERN FOR THIS AFTERNOON INTO TONIGHT WILL BE THE POTENTIAL
FOR LOCALLY HEAVY RAINS WITH WEAK STEERING CURRENTS LEADING TO
SLOW MOVING THUNDERSTORMS...ESPECIALLY ACROSS ACROSS THE
MOUNTAINS. EXPECT MOST OF THE CONVECTION TO DIMINISH THIS EVENING
WITH THE LOSS OF SOLAR HEATING. CAN NOT COMPLETELY DRIER IT
OUT...BECAUSE THERE IS ANOTHER UPPER DISTURBANCE ROTATING ACROSS
THE REGION OVERNIGHT INTO SUNDAY MORNING. WITH LOW LEVEL MOISTURE
AND LIGHT WINDS ANTICIPATE THAT AREAS OF FOG WILL FORM OVERNIGHT
ESPECIALLY IN LOCATION THAT RECEIVE RAINFALL ON SATURDAY. LOW
TEMPERATURE OVERNIGHT WILL BE MILD WITH READINGS FROM THE UPPER
50S IN THE MOUNTAINS TO THE MID 60S IN THE PIEDMONT.

UPPER RIDGE WILL HOLD FAST THROUGH SUNDAY BUT GRADUALLY START TO
FLATTEN OUT AND SHIFT EAST AS SURFACE HIGH PRESSURE CENTERED OFF THE
MID ATLANTIC COAST SURFACE SINKS FURTHER TO THE SOUTH. THE DAY TWO
CONVECTION KEEPS US IN GENERAL THUNDERSTORMS SUNDAY WITH BEST
DYNAMICS REMAINING TO OUR WEST. THE OROGRAPHIC FORCING WILL SERVE AS
THE PRIMARY MECHANISM FOR DIURNAL CONVECTION...ALONG WITH OUTFLOW
BOUNDARY INTERACTIONS AND POSSIBLY SOME WEAK UPPER SHORT WAVE
ENERGY. HIGH TEMPERATURES ON SUNDAY WILL RANGE FROM THE LOWER 70S IN
THE MOUNTAINS TO THE UPPER 80S IN THE PIEDMONT.

&&

.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
AS OF 300 PM EDT SATURDAY...

MODELS CONTINUE TO BE IN GOOD AGREEMENT DURING SHORT TERM PERIOD IN
MAINTAINING A SOUTHEASTERN UPPER RIDGE AMPLIFYING INTO THE
BLACKSBURG FORECAST AREA THROUGH MONDAY NIGHT BEFORE BEING GRADUALLY
FLATTENED BY A SHORT WAVE TROF EXPECTED TO MOVE EAST THROUGH THE
GREAT LAKES ON TUESDAY.

WITH THE UPPER RIDGE HOLDING UNTIL TUESDAY...SLOWLY INCREASING HEAT
AND HUMIDITY ON LIGHT SOUTHWESTERLY FLOW ALONG THE PERIPHERY OF THE
UPPER RIDGE WILL CONTINUE TO SUPPORT DEVELOPMENT OF MAINLY DIURNALLY-
DRIVEN SHOWERS AND THUNDERSTORMS...MOST NOTABLY IN THE MOUNTAINS
WHERE THETA-E VALUES WILL BE THE HIGHEST...AND WHERE LOCALIZED
FORCED ASCENT AND DIFFERENTIAL HEATING DUE TO OROGRAPHIC INFLUENCES
WILL BE MAXIMIZED TO PUNCH THROUGH WEAK MID-LEVEL CAPPING INVERSION.

FORECAST SOUNDINGS CONTINUE TO MAINTAIN RELATIVELY WARM TEMPERATURES
IN THE MID LEVELS OF THE ATMOSPHERE ALONG WITH WEAK SHEAR INTO
TUESDAY...SUCH THAT SEVERE WEATHER THREAT EVEN UP THROUGH FRONTAL
PASSAGE ON TUESDAY APPEARS TO BE EXTREMELY LIMITED. CORFIDI VECTORS
YIELD A SLOW...BUT SUFFICIENTLY PROGRESSIVE MOTION SUCH THAT UNLESS
TRAINING ALONG AN OUTFLOW BOUNDARY AND/OR ANCHORING ON A OROGRAPHIC
POINT OCCURS...FLASH FLOODING THREAT SHOULD ALSO REMAIN MINIMAL
DESPITE PRECIPITABLE WATER VALUES GRADUALLY CLIMBING UP TO AND
MAXING OUT IN THE 1.6 - 1.8 INCH RANGE SUNDAY INTO MONDAY.

PASSAGE OF SHORT WAVE TROF AND ATTENDANT COOL FRONT LATER TUESDAY
SHOULD SHOULD BRING AN END TO THREAT FOR SCATTERED SHOWERS/STORMS
BY/DURING TUESDAY EVENING AS COOL ADVECTION IN WEST...AND
DOWNSLOPING EAST OF THE BLUE RIDGE TAKES OVER...SETTING THE STAGE
FOR DRIER AND SLIGHTLY COOLER WEATHER LATER TUESDAY NIGHT INTO THE
FIRST PART OF THE LONGER TERM PERIOD.

TEMPERATURES THROUGH THE PERIOD WILL CONTINUE TO BE LARGELY GOVERNED
BY EXTENT OF CLOUD COVER AND INFLUENCE OF CONVECTIVE OUTFLOW
BOUNDARIES...BUT NOT EXPECTED TO BE THAT FAR OFF CLIMATOLOGICAL
NORMALS AREA-WIDE.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 300 PM EDT SATURDAY...

SURFACE HIGH PRESSURE BUILDING IN FROM THE NORTHWEST SHOULD MAINTAIN
DRY AND SLIGHTLY COOLER WEATHER FOR THE BLACKSBURG FORECAST AREA
WEDNESDAY INTO AT LEAST THURSDAY MORNING.

APPROACH OF YET ANOTHER SERIES OF NORTHERN STREAM IMPULSES EXPECTED
TO SUFFICIENTLY BUCKLE/BACK UPPER FLOW AGAIN IN THURSDAY/FRIDAY
TIMEFRAME TO SUPPORT THE DEVELOPMENT OF WIDELY SCATTERED SHOWERS OR
ISOLATED THUNDERSHOWERS...MAINLY ACROSS THE SOUTHWESTERN VA INTO THE
MOUNTAINS OF NW NC WHERE RETURN FLOW AND THETA-E WILL BE A BIT
HIGHER.

OTHERWISE...ANOTHER RETURN TO DRIER WEATHER LOOKS TO BE IN THE
OFFING BY NEXT SATURDAY AS PASSAGE OF NORTHERN STREAM WAVES
SUFFICIENTLY DEEPENS/REESTABLISHES UPPER TROF OVER NEW
ENGLAND...SUPPORTING SURFACE HIGH PRESSURE THAT WILL SLIDE SOUTHEAST
INTO NEW ENGLAND AND WEDGE SOUTHWESTWARD INTO THE MID ATLANTIC
STATES.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AS OF 200 AM EDT SUNDAY...

RADAR INDICATES ONLY A FEW LINGERING SHOWERS ACROSS THE AREA THIS
MORNING. OVERALL...SHOWER ACTIVITY THROUGH LATE MORNING WILL
REMAIN MINIMAL...HOWEVER EXPECT TO SEE LIGHT RETURNS PASS ACROSS
FROM TIME TO TIME. PATCHY FOG AND LOW CEILINGS WILL AGAIN BE THE
MORE SIGNIFICANT ISSUE OVERNIGHT...MORE SO ACROSS THE MOUNTAINS
AND ESPECIALLY IN AREAS WHICH RECEIVED SIGNIFICANT RAINFALL ON
SATURDAY. FOG WILL BURN OFF QUICKLY AFTER 9 AM WITH STRONG DAYTIME
HEATING...AND LOW CEILINGS WILL GRADUALLY LIFT AND TRANSITION TO
STRATOCU THROUGH THE REMAINDER OF THE MORNING.

FOR SUNDAY...LOOKING FOR ANOTHER ROUND OF SCATTERED SHOWERS AND
THUNDERSTORMS SIMILAR TO WHAT OCCURRED ON SATURDAY...WITH
CONVECTION DEVELOPING ALONG THE MOUNTAIN RIDGES BEGINNING AS EARLY
AS 17/16Z. SHOWERS AND THUNDERSTORMS WILL BECOME SCATTERED TO
NUMEROUS ACROSS THE MOUNTAINS DURING MID/LATE AFTERNOON...WITH
WESTERLY FLOW PUSHING SOME OF THIS ACTIVITY EAST ACROSS THE
PIEDMONT DURING LATE AFTERNOON INTO THE EVENING. STORMS WILL AGAIN
BE SLOW MOVING AND CAPABLE OF PRODUCING LOCALLY HEAVY RAINFALL FOR
PROLONGED PERIODS OF TIME. AS SUCH...LOOKING AT THE POTENTIAL OF
LOCALIZED MVFR/IFR CONDITIONS WITHIN THE HEAVIER RAINSHAFTS...
REDUCING VISIBILITIES TO A FEW HUNDRED FEET AT TIMES. CONVECTION
WILL START TO WANE TOWARD SUNSET WITH THE LOSS OF HEATING...BUT
EXPECT SHOWERS AND A FEW THUNDERSTORMS TO REMAIN ON THE RADAR AS
LATE AS 18/04Z.

MEDIUM TO HIGH CONFIDENCE IN CEILINGS...VISIBILITIES AND WINDS
DURING THE TAF PERIOD.

EXTENDED AVIATION DISCUSSION...

LATE NIGHT/EARLY MORNING FOG AND ASSOCIATED IFR-LIFR VSBYS/CIGS
ARE HIGHLY LIKELY SUNDAY NIGHT INTO MONDAY GIVEN THE SOUPY
ATMOSPHERE IN PLACE. LATE MONDAY INTO TUESDAY...A COLD FRONT MOVES
THROUGH. THUNDERSTORMS SHOULD BE MOST NUMEROUS IN COVERAGE AND
STRONGEST IN INTENSITY DURING THIS TIME FRAME FOR ALL
AREAS...ENDING FROM THE WEST DURING TUESDAY. LONGER PERIODS OF
MVFR CIGS/VSBYS APPEAR LIKELY MONDAY-TUESDAY. BEHIND THE COLD
FRONT...DRIER/COOLER CONDITIONS ARE EXPECTED WED-THU WITH MOSTLY
VFR CONDITIONS AS HIGH PRESSURE SLIDES IN FROM THE NW.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...RAB
NEAR TERM...JH/KK
SHORT TERM...WERT
LONG TERM...WERT
AVIATION...JH/NF



AREA FORECAST DISCUSSION

NWS GREEN BAY WI

 1010 PM CDT MON MAY 18 2015

UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE

.SHORT TERM...TONIGHT AND TUESDAY
ISSUED AT 235 PM CDT MON MAY 18 2015

THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW OCCLUDED
LOW PRESSURE MOVING EAST OVER WESTERN LAKE SUPERIOR.  A VERY CHILLY
AIRMASS FOR THIS TIME OF THE YEAR IS WRAPPING AROUND THE LOW AND
GRADUALLY MOVING EAST OVER THE WESTERN HALF OF WISCONSIN.  THE LOW
STRATUS HAS MOVED VERY LITTLE EASTWARD SO FAR TODAY...BUT SHOULD
GAIN SOME MOMENTUM THROUGH THE AFTERNOON AS THE COLDER AIR AT 850MB
OVER TAKES IT.  PLENTY OF OBS ARE REPORTING LIGHT RAIN/DRIZZLE...AND
EVEN A FEW FLAKES UPSTREAM OVER NORTHWEST WISCONSIN AND NORTHERN
MINNESOTA.  AS THE COLDER AIR AND LIGHT PRECIP SPREAD ACROSS THE
REGION...TEMPS AND PRECIP TRENDS ARE THE MAIN FORECAST CONCERNS.

TONIGHT...OCCLUDED LOW PRESSURE WILL MOVE EAST OVER LAKE SUPERIOR
AND NORTHERN ONTARIO AND WEAKEN AT THE SAME TIME.  AS WINDS SHIFT TO
THE NORTHWEST...COLD ADVECTION WILL CONTINUE ACROSS THE STATE
THROUGH THE NIGHT...DROPPING 850MB TEMPS TO AROUND -8C TO -10C.
DEEPER MOISTURE WILL BE ROTATING ACROSS NORTHERN WISCONSIN AND
COMBINED WITH UPSLOPE FLOW OFF LAKE SUPERIOR AND UNSTABLE
CONDITIONS...SHOULD SEE PERIODS OF LIGHT RAIN/DRIZZLE...MIXED WITH
SNOW AT TIMES.  TEMPERATURES WILL BE FALLING INTO THE 30-32 DEGREE
RANGE OVER NORTHERN WISCONSIN FOR A FEW HOURS LATE TONIGHT.  BUT
AREAS OVER THE UPPER PENINSULA AND NORTHWEST WISCONSIN HAVE NOT
OFFICIALLY STARTED THEIR GROWING SEASONS...SO WILL HIGHLIGHT THE
COLD IN A SPECIAL WEATHER STATEMENT.  ELSEWHERE...LOOK FOR A CLOUDY
AND BLUSTERY NIGHT.

TUESDAY...THERMAL TROUGHING AND FLOW OFF LAKE SUPERIOR ARGUE FOR A
CLOUDY/MOSTLY CLOUDY START TO THE DAY.  BUT SHOULD SEE CLOUDS
GRADUALLY ERODE FROM SOUTHWEST THROUGH NORTHEAST THROUGH THE DAY AS
CYCLONIC FLOW ABATES AND LOW LEVEL TEMPS MODERATE.  LOWERED MAX
TEMPS A DEGREE...AND WENT WITH HIGHS RANGING FROM THE MID 40S NORTH
TO MID 50S SOUTH.

.LONG TERM...TUESDAY NIGHT THROUGH MONDAY
ISSUED AT 235 PM CDT MON MAY 18 2015

FROST/FREEZE HEADLINE POTENTIAL TUESDAY NIGHT AND WEDNESDAY NIGHT...
AND PCPN TRENDS FOR THE MEMORIAL DAY WEEKEND...ARE THE MAIN FCST
CONCERNS.

CANADIAN HIGH PRESSURE WILL BE RIDGED OVER THE WSTRN GREAT LAKES
ON TUESDAY NIGHT...AND WILL BRING LIGHT WINDS TO THE FORECAST AREA.
EXPECT SKIES TO BE MOSTLY CLEAR OVER NORTHERN WI...LEADING TO
WIDESPREAD SUB-FREEZING TEMPERATURES. AVERAGE MIXING RATIOS OF
2.5 TO 3 G/KG SUPPORT THE POTENTIAL FOR MIN TEMPS AS COLD AS
20 TO 25 AT THE CLIMATOLOGICALLY FAVORED COLD SPOTS. HIGH CLOUDS
ARE EXPECTED TO INCREASE OVER C/EC WI...ON THE ANTICYCLONIC SHEAR
SIDE...AND WITHIN THE RRQ...OF A STRONG UPPER JET STREAK. WHILE
THIS LIKELY WILL NOT PREVENT FROST DEVELOPMENT IN OUR SOUTHERN
COUNTIES...IT SHOULD AT LEAST KEEP MOST PLACES ABOVE FREEZING.
WILL NOT ISSUE ANY HEADLINES WITH THIS FORECAST PACKAGE...BUT
FROST/FREEZE HEADLINES APPEAR IMMINENT.

THE POTENTIAL FOR FROST WILL CONTINUE INTO WEDNESDAY NIGHT...
BUT SHOULD SHIFT TO MAINLY NORTHERN WI...WHERE MIN TEMPS ARE
EXPECTED TO DROP INTO THE LOWER TO MIDDLE 30S.

A WEAK BACK DOOR COLD FRONT IS EXPECTED TO DROP SOUTH THROUGH
THE REGION SOMETIME DURING THE WEDS NGT TO THU NGT PERIOD. THE
GFS IS FOCUSING ON WEDS NGT/THU...WHILE THE ECMWF IS SLOWER
AND BRINGS THE FRONT THROUGH THU AND EARLY THU NGT. A VERY
DRY AIR MASS SHOULD PRECLUDE ANY PCPN DEVELOPMENT.

CANADIAN HIGH PRESSURE WILL RETURN TO THE WSTRN GREAT LAKES
FRIDAY...AND SHOULD HOLD ANY PCPN AT BAY THROUGH AT LEAST
SATURDAY.

A COLD FRONT/INVERTED SFC TROF AND UPPER TROF WILL IMPACT THE
REGION FOR THE LATTER HALF OF THE MEMORIAL DAY WEEKEND...BUT
TIMING DIFFERENCES ARE SIGNIFICANT BETWEEN THE MODELS. THE GFS
HAS PCPN OVER THE REGION FROM SAT NGT THROUGH MONDAY...WITH THE
HEAVIEST QPF FCST ON SUNDAY. THE ECMWF IS SLOWER...AND FOCUSES
MOST OF THE PCPN DURING THE SUNDAY NIGHT AND MONDAY PERIODS.
DUE TO THE TIMING DIFFERENCES...HAVE BACKED OFF ON LIKELY POPS
FOR ANY SPECIFIC PERIOD...BUT OVERALL TRENDS SUPPORT AT LEAST
A PERIOD OR TWO OF MODERATE RAINFALL.

SLIGHTLY BLO NORMAL TEMPERATURES ARE EXPECTED AT THE BEGINNING
AND END OF THE EXTENDED PERIOD...WITH NEAR NORMAL READINGS FOR
THE REST OF THE DAYS.
&&

.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1009 PM CDT MON MAY 18 2015

CLOUDS AND COLD AIR WILL CONTINUE TO POUR INTO THE
AREA OVERNIGHT ON NORTHWEST WINDS. MAINLY MVFR CIGS ACROSS THE
AREA OVERNIGHT WITH POCKETS OF IFR CIGS AND MVFR VSBYS DUE TO
SHOWERS OVER NORTHERN WISCONSIN. GUSTY WINDS WILL CONTINUE TO
SUBSIDE OVERNIGHT. COOL DRY HIGH PRESSURE SETTLING INTO THE GREAT
LAKES REGION WILL PRODUCE VFR CIGS LATER TUESDAY.
&&

.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM.....MPC
LONG TERM......KIECKBUSCH
AVIATION.......TDH







AREA FORECAST DISCUSSION

NWS LA CROSSE WI

 600 PM CDT SUN MAY 17 2015

.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 303 PM CDT SUN MAY 17 2015

MAIN CONCERN IS SEVERE THREAT LATE THIS AFTERNOON INTO THIS
EVENING.

LATEST WATER VAPOR SATELLITE IMAGERY SHOWS UPPER LEVEL LOW/TROUGH
OVER EASTERN SOUTH DAKOTA AND WESTERN MINNESOTA...IN ADDITION A
SHORTWAVE TROUGH OVER SOUTHEAST NEBRASKA AND SOUTHWEST IOWA.
LATEST 19Z SURFACE ANALYSIS INDICATES SURFACE LOW OVER SOUTHEAST
NORTH DAKOTA AND WEST CENTRAL MINNESOTA...WITH A COLD FRONT
EXTENDING SOUTH INTO WESTERN IOWA. LATEST SATELLITE IMAGERY SHOWS
STRATUS OVER FORECAST AREA BECOMING MORE CELLUAR AND SCATTERED
SHOWERS DEVELOPED OVER NORTH CENTRAL WISCONSIN AND PARTS OF
SOUTHEAST MINNESOTA PER LATEST ARX RADAR.

WITH THE STRATUS DECK OVER MUCH OF THE REGION THROUGH EARLY
AFTERNOON HOURS...THIS HAS LIMITED INSTABILITY OVER FORECAST AREA
THIS AFTERNOON...WITH THE 17.19Z LAPS SHOWING 200-800 J/KG OVER
FORECAST AREA AND AROUND 1000-1200 J/KG ALONG AND JUST AHEAD OF
THE COLD FRONT. THE LATEST SPC MESOSCALE ANALYSIS INDICATES 40
KNOTS OF 0-6KM SHEAR OVER FORECAST AREA...WITH THE BEST SHEAR IN
THE 0-3KM SHEAR PER 17.18Z RAP OF 30 TO 40 KNOTS ALONG AND AHEAD
OF SURFACE FRONT. SPC MESOSCALE 0-1KM SHEAR INDICATES ABOUT 10 TO
20 KNOTS ALONG AND AHEAD OF COLD FRONT. WITH MINIMAL INSTABILITY
AND SHEAR DECREASING OVER FORECAST AREA...SEVERE THREAT OVER
FORECAST AREA HAS DECREASED. HOWEVER CANNOT RULE OUT AN ISOLATED
SEVERE THUNDERSTORM WITH DAMAGING WINDS...LARGE HAIL OR POSSIBLY
AN ISOLATED TORNADO LATE THIS AFTERNOON INTO THIS EVENING.

MONDAY...FORECAST AREA REMAINS UNDER THE INFLUENCE OF THE UPPER
LEVEL LOW/TROUGH OVER SOUTHERN ONTARIO AND LAKE SUPERIOR. THE
17.12Z GFS/NAM INDICATE COLD AIR ADVECTING INTO THE FORECAST
AREA...WITH 925MB TEMPERATURES FALLING TO 0 TO MINUS 2 DEGREES
CELSIUS OVER THE FORECAST AREA. HIGH TEMPERATURES ARE EXPECTED TO
BE WELL BELOW NORMAL...WITH READINGS IN THE UPPER 40S TO LOWER 60S
ACROSS THE FORECAST AREA. TIGHT PRESSURE GRADIENT WILL ALLOW FOR
WINDS TO BE SUSTAINED AT 15 TO 20 KNOTS AND GUSTS OF 20 TO 30
KNOTS.

.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 303 PM CDT SUN MAY 17 2015

TUESDAY INTO WEDNESDAY...SURFACE RIDGE BUILDS INTO MUCH OF MINNESOTA
AND NORTHERN WISCONSIN. SUBSIDENCE UNDERNEATH THE RIDGE SHOULD ALLOW
FOR DRY WEATHER AND SLIGHTLY BELOW NORMAL TEMPERATURES TUESDAY AND
TUESDAY NIGHT. PATCHY TO AREAS OF FROST IS POSSIBLE ACROSS PARTS OF
CENTRAL WISCONSIN TUESDAY NIGHT INTO WEDNESDAY MORNING. MID TO HIGH
CLOUDS STREAMING AHEAD OF SHORTWAVE TROUGH SOUTHWEST OF FORECAST
AREA MAY NOT ALLOW TEMPERATURES TO FALL INTO THE LOWER TO MIDDLE
30S. TIMING OF MOISTURE ABOVE 700MB WILL BE THE BIGGEST FACTOR AND
THIS IS EVIDENT BY THE 17.12Z GFS/NAM.

WEDNESDAY...SHORTWAVE TROUGH FLATTENS UPPER LEVEL SHORTWAVE RIDGE
WEDNESDAY OVER NEBRASKA AND IOWA. WITH DRY AIRMASS IN PLACE OVER
FORECAST AREA AND THE DEEPER FORCING/LIFT ASSOCIATED WITH SHORTWAVE
TROUGH SOUTH OF FORECAST AREA...HIGHER PRECIPITATION/SHOWER
CHANCES WILL REMAIN MAINLY SOUTH OF FORECAST AREA WEDNESDAY.
HOWEVER...THE 17.12Z GFS/NAM SUGGEST 500-300MB PV ADVECTION ALONG
THE MINNESOTA AND IOWA BORDER DURING THE DAY WEDNESDAY. WILL
INTRODUCE A SMALL PRECIPITATION CHANCE OVER THE EXTREME SOUTH PART
OF THE FORECAST AREA...AS THE 17.12 GFS/NAM DEVELOP LIGHT QPF...A
HUNDREDTH OR TWO...OVER THE EXTREME SOUTHERN PART OF THE FORECAST
AREA.

MAIN FORECAST CONCERNS FROM WEDNESDAY NIGHT INTO MEMORIAL DAY
WEEKEND ARE PRECIPITATION CHANCES FOR MEMORIAL DAY WEEKEND. THE
17.12Z GFS/ECMWF/GEM ARE IN GOOD AGREEMENT IN BUILDING IN
SHORTWAVE/SURFACE RIDGE INTO THE UPPER MIDWEST AND GREAT LAKES
REGION WEDNESDAY NIGHT INTO FRIDAY PROVIDING DRY WEATHER AND
SLIGHTLY TO NEAR NORMAL TEMPERATURES BOTH DAYS. FOCUS TURNS TO
MEMORIAL DAY WEEKEND...WHERE THE 17.12Z GFS/ECMWF ARE IN GOOD
AGREEMENT IN EJECTING PIECES OF ENERGY OUT OF UPPER LEVEL LOW/TROUGH
OVER THE SOUTHWEST UNITED STATES INTO THE CENTRAL UNITED STATES.
BOTH THE 17.12Z GFS/ECMWF SHOW INCREASING LOW LEVEL JET/MOISTURE
TRANSPORT/CONVERGENCE AND LIFT/FORCING SATURDAY INTO SUNDAY INTO THE
FORECAST AREA. WILL CONTINUE TO TREND OF SHOWERS AND THUNDERSTORMS
SATURDAY INTO SUNDAY.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 600 PM CDT SUN MAY 17 2015

SCATTERED SHRA/TS WILL CONTINUE TO PUSH NORTH/NORTHEAST THIS
EVENING...LIKELY WORKING NORTH OF KRST/KLSE BY 01Z OR SHORTLY
AFTERNOON. BRIEF MVFR CONDITIONS WITH ANY STORM.

EXPECTING SOME CLEARING AND MOSTLY SCT VFR CONDITIONS INTO THE
OVERNIGHT. AS THE RESPONSIBLE STORM SYSTEM MOVES INTO SOUTHERN
CANADA...CLOUD SHIELD WEST OF THE LOW LOOKS TO SINK ACROSS THE TAF
SITES AFTER 12Z MONDAY. MVFR CIGS LOOK LIKELY FOR KRST FOR MUCH OF
THE DAY...AND PERHAPS FOR A FEW HOURS AT KLSE.

TIGHT PRESSURE GRADIENT WILL KEEP WINDS STRONG AND GUSTY TONIGHT
THROUGH MONDAY. SUSTAINED NEAR 20 KTS FOR KRST. LOOK FOR A SHIFT TO
WEST WINDS OVERNIGHT AS A COLD FRONT SLIDES WEST-EAST ACROSS THE
AREA.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&

$$

SHORT TERM...DTJ
LONG TERM...DTJ
AVIATION...RIECK



AREA FORECAST DISCUSSION

NWS GREEN BAY WI

 552 PM CDT SUN MAY 17 2015

UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE

.SHORT TERM...TONIGHT AND MONDAY
ISSUED AT 229 PM CDT SUN MAY 17 2015

THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW AN OCCLUDED
LOW PRESSURE SYSTEM SPINNING OVER THE EASTERN DAKOTAS.  SHORTWAVES
ARE ROTATING NORTHWARD AHEAD OF THIS OCCLUDED CYCLONE...THE
STRONGEST OF WHICH IS LOCATED OVER EASTERN IOWA.  A PWAT AXIS IS
MOVING ACROSS WISCONSIN EARLY THIS AFTERNOON...WHICH COMBINED WITH
MOISTURE CONVERGENCE...IS CONTRIBUTING TO SCATTERED SHOWER
DEVELOPMENT OVER CENTRAL WISCONSIN.  CLOUD COVER HAS SIGNIFICANTLY
SLOWED THE HEATING CURVE SO FAR TODAY...KEEPING ML CAPES BELOW 200
J/KG.  WITH SHOWER COVERAGE EXPECT TO INCREASE THROUGH THE
AFTERNOON...IT WILL BE TOUGH TO SEE MUCH OF AN INCREASE OF
INSTABILITY.  STILL THOUGH...RADAR ECHOES SUGGEST SOME THUNDERSTORMS
WILL BE POSSIBLE...AND ANY STORMS COULD BRING DOWN STRONG WINDS FROM
ALOFT.  WILL HAVE TO KEEP A MENTION OF ISOLATED DAMAGING WINDS
THROUGH EARLY THIS EVENING. OTHERWISE...THE LATEST HRRR CONGEALS THE
SHOWER ACTIVITY INTO BAND AND PROGRESSES IT ACROSS THE FORECAST AREA
FOR THE REST OF THE AFTERNOON.

TONIGHT...LOW PRESSURE WILL MOVE EAST ACROSS NORTHERN
MINNESOTA...WHILE A COLD FRONT WILL PUSH EAST THROUGH ALL BUT FAR
EASTERN WISCONSIN OVERNIGHT.  THOUGH SHORTWAVE ENERGY WILL BE
ROTATING NORTHEAST OVER NORTHWEST WISCONSIN THROUGH THE
EVENING...CONCERNED THAT STRONG DRYING AND INCREASING CAPPING IN THE
MID-LEVELS WILL EVEN FURTHER LIMIT THUNDERSTORM POTENTIAL FOR THE
FIRST COUPLE HOURS IN THE EVENING.  WILL KEEP A MENTION OF ISOLATED
DAMAGING WINDS THROUGH 02Z IN CASE SOME THUNDERSTORMS MAKE A RUN
INTO N-C WISCONSIN FROM MINNESOTA.  ONCE THE THREAT OF STORMS ENDS...MODELS
SHOW CLEARING TAKING PLACE UNTIL LOW CLOUDS FLOOD EAST BEHIND THE
COLD FRONT LATE TONIGHT.  LOW TEMPS NEAR 60 OVER THE EAST...BUT
COOLING TO NEAR 50 OVER THE WEST.

MONDAY...OCCLUDED LOW PRESSURE WILL BE WEAKENING AS IT MOVES TO THE
EAST ACROSS LAKE SUPERIOR.  WEST WINDS ON THE SOUTHERN FLANK OF THE
LOW WILL BE COLD ADVECTING THROUGH THE DAY...WHILE PUSHING IN WRAP
AROUND MOISTURE.  SHOULD SEE AMPLE CLOUD COVER OVER CENTRAL AND
NORTH-CENTRAL WISCONSIN THROUGH THE DAY...BUT EAST-CENTRAL WISCONSIN
WILL LIKELY SEE SOME SUN IN THE MORNING BEFORE CLOUDS INCREASE IN
THE AFTERNOON.  WITH THE SUNSHINE...TEMPS SHOULD WARM TO NEAR 70 IN
THE EAST...BUT ONLY INTO THE MID AND UPPER 50S OVER THE WEST.

.LONG TERM...MONDAY NIGHT THROUGH SUNDAY
ISSUED AT 229 PM CDT SUN MAY 17 2015

MUCH COOLER TEMPERATURES FOR THE FIRST HALF OF THE WORK WEEK...DRY
AND MILDER CONDITIONS FOR THE LATTER HALF...AND A POSSIBLE RETURN
TO WET WEATHER LATER IN THE MEMORIAL DAY WEEKEND...ARE THE MAIN
FCST CONCERNS.

THE REMNANTS OF THE UPPER LOW WILL TRACK ACROSS NORTHERN LAKE SUPERIOR
ON MONDAY NIGHT...FOLLOWED BY A S/W TROF PASSING NORTH OF WI ON TUESDAY.
UNSEASONABLY COLD AIR (H8 TEMPS -8 TO -10 C) WILL FLOW INTO THE REGION
ON NNW WINDS...SETTING THE STAGE FOR SOME LAKE-ENHANCED SHOWERS OVER
NC WI. LOW-LEVEL TEMPS AND THICKNESSES SUPPORT A MIX THEN CHANGEOVER
TO SNOW LATE MONDAY NIGHT INTO TUESDAY MORNING...WITH LITTLE OR NO
ACCUMULATION EXPECTED. ANY LINGERING PCPN SHOULD END TUESDAY AFTERNOON
AS CANADIAN HIGH PRESSURE BUILDS INTO THE REGION.

HIGH PRESSURE WILL COVER THE AREA TUESDAY NIGHT INTO WEDNESDAY. STILL
EXPECTING FROST TUESDAY NIGHT...BUT GETTING A LITTLE CONCERNED ABOUT
THE POSSIBILITY OF THICKER HIGH LEVEL CLOUDS...DUE TO THE PRESENCE
OF A STRONG JET STREAK OVER THE REGION. RIGHT NOW...HAVE JUST
BUMPED UP CLOUD COVER A BIT OVER C/EC WI...BUT KEPT MOSTLY CLEAR
SKIES OVER NORTHERN WI. WILL CONTINUE TO CARRY WIDESPREAD FROST OR
FREEZE CONDITIONS OVER NORTHERN WI...AND PATCHY FROST OVER MOST OF
C/EC WI.

A WEAK BACK DOOR COLD FRONT WILL SAG THROUGH THE FORECAST AREA THURSDAY
INTO THURSDAY NIGHT...BUT WILL NOT HAVE ANY MOISTURE TO WORK WITH...SO
DRY WEATHER WILL PREVAIL. BEHIND THE FRONT...CANADIAN HIGH PRESSURE
WILL REESTABLISH ITSELF OVER THE WESTERN GREAT LAKES...AND IS EXPECTED
TO LINGER INTO SATURDAY. ABUNDANT SUNSHINE SHOULD BRING A RETURN TO
NEAR NORMAL TEMPERATURES FOR THE LATTER HALF OF THE WEEK.

AN UPPER TROF...LOW PRESSURE SYSTEM AND ASSOCIATED COLD FRONT WILL
IMPACT THE REGION FROM SATURDAY NIGHT INTO SUNDAY. GULF MOISTURE
IS EXPECTED TO FLOW INTO THE REGION AHEAD OF THE FRONT...WITH
PRECIPITABLE WATER VALUES REACHING 1.00-1.25 INCHES. HAVE RAMPED
POPS UP TO LIKELY FOR SUNDAY. THE ECMWF PULLS MOST OF THE PCPN OUT
OF THE REGION SUNDAY EVG...WHILE THE GFS HANGS ONTO SIGNIFICANT
QPF INTO MEMORIAL DAY...SO FCST CONFIDENCE WANES BEYOND SUNDAY.
&&

.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 552 PM CDT SUN MAY 17 2015

MARGINAL TO STRONG SHEAR ALONG WITH MARGINAL INSTABILITY WILL
CONTINUE TO PRODUCE AN ENVIRONMENT FOR THE DEVELOPMENT OF STORMS
THIS SUNDAY EVENING. PRIMARY FOCUS OF STRONGER STORMS THIS
EVENING APPEAR TO BE OVER THE NORTHWEST HALF THE STATE INCLUDING
PARTS OF CENTRAL AND NORTH CENTRAL WISCONSIN. IFR CONDITIONS WITH
LIFR CIGS WILL LINGER ALONG THE LAKE MICHIGAN SHORE LINE.
SOUTHWEST WINDS WILL IMPROVE CONDITIONS OVERNIGHT. OTHERWISE AFTER
A PERIOD OF VFR CONDITIONS OVERNIGHT...MVFR CIGS WILL FILTER INTO
THE STATE FROM NORTHWEST TO SOUTHEAST THROUGH MONDAY WITH BLUSTERY
WEST TO NORTHWEST WINDS.
&&

.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM.....MPC
LONG TERM......KIECKBUSCH
AVIATION.......TDH








AREA FORECAST DISCUSSION

NWS MILWAUKEE/SULLIVAN WI

 330 PM CDT SUN MAY 17 2015

.SHORT TERM...

TONIGHT...FORECAST CONFIDENCE MEDIUM.

THE HRRR MODEL HAS BEEN CONSISTENT TODAY AND SO FAR CORRECT. OTHER
MESO MODELS ARE SIMILAR. A LINE OF SHOWERS AND THUNDERSTORMS WAS
ORIENTED ROUGHLY NORTH TO SOUTH ACROSS THE CENTRAL MKX FORECAST AREA
AT 2 PM THIS AFTERNOON. THIS LINE IS SLOWLY TRACKING EAST WITH MID
LEVEL VORTICITY ADVECTION. THESE ARE WORKING OFF THE HIGHER CAPE
AXIS THAT DEVELOPED OVER INLAND WI AREAS AND ALSO WEAK SURFACE
CONVERGENCE. THE CONVECTION IS LOW-TOPPED SINCE MID LEVEL LAPSE
RATES ARE WEAK. THEREFORE... MANY OF THE ECHO TOPS ARE BENEATH THE
FREEZING LEVEL OF 12.5 KFT AND ARE NOT EVEN PRODUCING THUNDER.
SEVERAL CELLS HAVE TOPS AROUND 20 KFT AND WE ARE SEEING CLOUD TO
GROUND LIGHTNING STRIKES WITH THEM.

PER THE HRRR AND OTHER MESO MODELS... THESE SHOWERS WILL CONTINUE
EAST THROUGH 6 PM... ALL THE WAY THROUGH MILWAUKEE. EXPECT HEAVY
DOWNPOURS. BRIEF LOCALIZED FLOODING IS POSSIBLE IN URBAN AREAS.

THERE IS A BREAK BEHIND THIS LINE OF SHOWERS AND STORMS LATE THIS
AFTERNOON. LOOK FOR GUSTY SOUTH-SOUTHWEST WINDS AS THE LOW LEVELS
MIX OUT AND DEWPOINTS DROP TO AROUND 60. CAPE/INSTABILITY WILL LOWER
IN THIS AREA. 0-6KM BULK SHEAR WILL REMAIN HIGH... AROUND 40 KT.

THERE IS ONE MORE CHANCE FOR STORMS ACROSS SOUTHERN WI THIS
EVENING... BUT THE CHANCE IS BECOMING VERY LOW. THE HRRR... NAMNEST
AND OTHER MESO MODELS ARE SHOWING QUITE A DRY SCENARIO FOR OUR AREA.
THE FEATURE WE HAVE BEEN FOCUSING OUR ATTENTION ON FOR SEVERE
POTENTIAL IS AN UPPER LEVEL WAVE AND A SURFACE PRE-FRONTAL TROUGH
ASSOCIATED WITH AN OCCLUDING LOW PRESSURE SYSTEM OVER THE EASTERN
DAKOTAS AND WEST CENTRAL MN. THE UPPER WAVE NOW LOOKS LIKE IT WILL
COME THROUGH SOUTHERN WI A LITTLE AHEAD OF THE PRE-FRONTAL TROUGH...
SO DEVELOPMENT OF STORMS WILL BE HARDER TO ACHIEVE. IF ANY STORMS
DEVELOP... THE CAPE WILL BE MARGINAL AND SHEAR WILL BE HIGH. THUS...
THERE IS STILL A SMALL RISK FOR SEVERE. SPC STILL HAS OUR AREA IN A
SLIGHT RISK FOR SEVERE STORMS.

SKIES SHOULD CLEAR LATE THIS EVENING WITH THE DRY AIR WRAPPING INTO
SOUTHERN WI AS THE SURFACE LOW TRACKS INTO NORTHEAST MN. WINDS WILL
SHIFT TO THE SW AND WEST TOWARD MORNING.

.MONDAY...FORECAST CONFIDENCE HIGH.

THE SURFACE/925MB COLD FRONT WILL TRACK THROUGH SOUTHERN WI DURING
THE DAY MONDAY. IT WILL BE SLOW TO REACH SOUTHEAST WI... THUS MAX
TEMPS WILL BE IN THE MID 70S THERE. THE DELLS AREA WILL BE COOLEST
WITH HIGHS AROUND 60. EXPECT BRISK AND GUSTY WEST WINDS DUE TO A
STRONG PRESSURE GRADIENT OVER THE REGION.

MONDAY NIGHT THROUGH WEDNESDAY...FORECAST CONFIDENCE MEDIUM.

THE UPPER LOW OVER NRN MN WILL BECOME AN OPEN WAVE AND MOVE ACROSS
LAKE SUPERIOR AND INTO ONTARIO CANADA MON NT. A WEAKER SHORTWAVE
TROUGH WILL ALSO MOVE ACROSS CENTRAL WI DURING THAT TIME. THE
SHORTWAVE WILL LIKELY AID IN BROKEN STRATUS SHIFTING SOUTH INTO S
WI ALONG WITH THE NWLY SFC FLOW AND COLD ADVECTION. NLY SFC FLOW
WILL CONTINUE INTO TUE BUT WITH WEAKENING COLD ADVECTION. DAYTIME
HEATING AND DRIER AIR SHOULD BE ENOUGH TO SCATTER OUT THE STRATUS
DECK. HOWEVER HIGH TEMPS WILL REMAIN WELL BELOW NORMAL WITH 925 MB
TEMPS ONLY WARMING TO 5-7C.

AN UPPER LOW OVER THE WRN USA WILL THEN OPEN UP AS A SHORTWAVE
TROUGH AND MOVE TOWARD WI FOR WED. DESPITE MID LEVEL FRONTOGENESIS
OVER THE REGION...KEPT THE FCST DRY AS MUCH OF THE LOW TO MID
LEVEL WARM...MOIST ADVECTION STAYS TO THE SOUTH. THUS EXPECT MO
CLOUDY SKIES FROM MIDDLE TO HIGH CLOUDS. THE CLOUDS WILL KEEP THE
HIGH TEMPS MAINLY IN THE 50S FOR THE 2ND DAY IN A ROW.


.LONG TERM...

THURSDAY THROUGH SUNDAY...FORECAST CONFIDENCE MEDIUM.

THE SRN PERIPHERY OF AN UPPER TROUGH WILL MOVE ACROSS THE NORTHERN
AND EASTERN GREAT LAKES THU-FRI. THIS IS EXPECTED TO BRING A WEAK
AND DRY BACKDOOR COLD FRONT ACROSS SRN WI ON FRI. HIGH PRESSURE
WILL THEN FOLLOW FROM THE NORTHERN GREAT LAKES TO THE EASTERN
GREAT LAKES FOR FRI-SAT. FOR SAT NT AND SUN AN UPPER TROUGH WILL
EJECT NEWD TOWARD WI FROM THE 4 CORNERS REGION ALONG WITH ITS SFC
TROUGH. A GOOD SURGE OF WARM...MOIST ADVECTION AND SHOWERS/TSTORMS
ARE EXPECTED. TEMPS WILL RETURN TO NEAR NORMAL FOR THE THU-SUN
PERIOD.


&&

.AVIATION/00Z TAFS/...

AN AREA OF SHOWERS AND THUNDERSTORMS OVER SOUTH CENTRAL WI SHOULD
EXPAND AS IT TRACKS INTO SOUTHEAST WI THROUGH 6 PM. THIS WILL BE
ABOUT A 2 HOUR PERIOD OF MODERATE TO HEAVY RAIN AND OCCASIONAL
THUNDER.

LOOK FOR A QUIET PERIOD OF WEATHER LATE THIS AFTERNOON. THERE IS ONE
MORE SMALL CHANCE FOR THUNDERSTORMS EARLY THIS EVENING... BUT THAT
CHANCE IS NOW LOOKING VERY LOW.

THE RISK FOR SEVERE WEATHER HAS DECREASED... BUT ISOLATED SEVERE
STORMS ARE STILL POSSIBLE.

LOOK FOR CLEARING SKIES OVERNIGHT. GUSTY WEST WINDS AND SCATTERED TO
BROKEN VFR CUMULUS CLOUDS EXPECTED MONDAY.

&&

.MARINE...

DENSE FOG ADVISORY WAS EXTENDED UNTIL 00Z/ 7PM THIS EVENING DUE TO
PERSISTENT SOUTHEAST WINDS AND WARM AND HUMID AIR OVER THE LAKE.
INCREASING SOUTH TO SOUTHWEST WINDS SHOULD PUSH ANY LINGERING FOG
OUT OF THE NEARSHORE WATERS THIS EVENING.


&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...DENSE FOG ADVISORY UNTIL 7 PM CDT THIS AFTERNOON FOR LMZ643>646.

&&

$$

TONIGHT/MONDAY AND AVIATION/MARINE...MRC
MONDAY NIGHT THROUGH SUNDAY...GEHRING



AREA FORECAST DISCUSSION

NWS LA CROSSE WI

 303 PM CDT SUN MAY 17 2015

.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 303 PM CDT SUN MAY 17 2015

MAIN CONCERN IS SEVERE THREAT LATE THIS AFTERNOON INTO THIS
EVENING.

LATEST WATER VAPOR SATELLITE IMAGERY SHOWS UPPER LEVEL LOW/TROUGH
OVER EASTERN SOUTH DAKOTA AND WESTERN MINNESOTA...IN ADDITION A
SHORTWAVE TROUGH OVER SOUTHEAST NEBRASKA AND SOUTHWEST IOWA.
LATEST 19Z SURFACE ANALYSIS INDICATES SURFACE LOW OVER SOUTHEAST
NORTH DAKOTA AND WEST CENTRAL MINNESOTA...WITH A COLD FRONT
EXTENDING SOUTH INTO WESTERN IOWA. LATEST SATELLITE IMAGERY SHOWS
STRATUS OVER FORECAST AREA BECOMING MORE CELLUAR AND SCATTERED
SHOWERS DEVELOPED OVER NORTH CENTRAL WISCONSIN AND PARTS OF
SOUTHEAST MINNESOTA PER LATEST ARX RADAR.

WITH THE STRATUS DECK OVER MUCH OF THE REGION THROUGH EARLY
AFTERNOON HOURS...THIS HAS LIMITED INSTABILITY OVER FORECAST AREA
THIS AFTERNOON...WITH THE 17.19Z LAPS SHOWING 200-800 J/KG OVER
FORECAST AREA AND AROUND 1000-1200 J/KG ALONG AND JUST AHEAD OF
THE COLD FRONT. THE LATEST SPC MESOSCALE ANALYSIS INDICATES 40
KNOTS OF 0-6KM SHEAR OVER FORECAST AREA...WITH THE BEST SHEAR IN
THE 0-3KM SHEAR PER 17.18Z RAP OF 30 TO 40 KNOTS ALONG AND AHEAD
OF SURFACE FRONT. SPC MESOSCALE 0-1KM SHEAR INDICATES ABOUT 10 TO
20 KNOTS ALONG AND AHEAD OF COLD FRONT. WITH MINIMAL INSTABILITY
AND SHEAR DECREASING OVER FORECAST AREA...SEVERE THREAT OVER
FORECAST AREA HAS DECREASED. HOWEVER CANNOT RULE OUT AN ISOLATED
SEVERE THUNDERSTORM WITH DAMAGING WINDS...LARGE HAIL OR POSSIBLY
AN ISOLATED TORNADO LATE THIS AFTERNOON INTO THIS EVENING.

MONDAY...FORECAST AREA REMAINS UNDER THE INFLUENCE OF THE UPPER
LEVEL LOW/TROUGH OVER SOUTHERN ONTARIO AND LAKE SUPERIOR. THE
17.12Z GFS/NAM INDICATE COLD AIR ADVECTING INTO THE FORECAST
AREA...WITH 925MB TEMPERATURES FALLING TO 0 TO MINUS 2 DEGREES
CELSIUS OVER THE FORECAST AREA. HIGH TEMPERATURES ARE EXPECTED TO
BE WELL BELOW NORMAL...WITH READINGS IN THE UPPER 40S TO LOWER 60S
ACROSS THE FORECAST AREA. TIGHT PRESSURE GRADIENT WILL ALLOW FOR
WINDS TO BE SUSTAINED AT 15 TO 20 KNOTS AND GUSTS OF 20 TO 30
KNOTS.

.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 303 PM CDT SUN MAY 17 2015

TUESDAY INTO WEDNESDAY...SURFACE RIDGE BUILDS INTO MUCH OF MINNESOTA
AND NORTHERN WISCONSIN. SUBSIDENCE UNDERNEATH THE RIDGE SHOULD ALLOW
FOR DRY WEATHER AND SLIGHTLY BELOW NORMAL TEMPERATURES TUESDAY AND
TUESDAY NIGHT. PATCHY TO AREAS OF FROST IS POSSIBLE ACROSS PARTS OF
CENTRAL WISCONSIN TUESDAY NIGHT INTO WEDNESDAY MORNING. MID TO HIGH
CLOUDS STREAMING AHEAD OF SHORTWAVE TROUGH SOUTHWEST OF FORECAST
AREA MAY NOT ALLOW TEMPERATURES TO FALL INTO THE LOWER TO MIDDLE
30S. TIMING OF MOISTURE ABOVE 700MB WILL BE THE BIGGEST FACTOR AND
THIS IS EVIDENT BY THE 17.12Z GFS/NAM.

WEDNESDAY...SHORTWAVE TROUGH FLATTENS UPPER LEVEL SHORTWAVE RIDGE
WEDNESDAY OVER NEBRASKA AND IOWA. WITH DRY AIRMASS IN PLACE OVER
FORECAST AREA AND THE DEEPER FORCING/LIFT ASSOCIATED WITH SHORTWAVE
TROUGH SOUTH OF FORECAST AREA...HIGHER PRECIPITATION/SHOWER
CHANCES WILL REMAIN MAINLY SOUTH OF FORECAST AREA WEDNESDAY.
HOWEVER...THE 17.12Z GFS/NAM SUGGEST 500-300MB PV ADVECTION ALONG
THE MINNESOTA AND IOWA BORDER DURING THE DAY WEDNESDAY. WILL
INTRODUCE A SMALL PRECIPITATION CHANCE OVER THE EXTREME SOUTH PART
OF THE FORECAST AREA...AS THE 17.12 GFS/NAM DEVELOP LIGHT QPF...A
HUNDREDTH OR TWO...OVER THE EXTREME SOUTHERN PART OF THE FORECAST
AREA.

MAIN FORECAST CONCERNS FROM WEDNESDAY NIGHT INTO MEMORIAL DAY
WEEKEND ARE PRECIPITATION CHANCES FOR MEMORIAL DAY WEEKEND. THE
17.12Z GFS/ECMWF/GEM ARE IN GOOD AGREEMENT IN BUILDING IN
SHORTWAVE/SURFACE RIDGE INTO THE UPPER MIDWEST AND GREAT LAKES
REGION WEDNESDAY NIGHT INTO FRIDAY PROVIDING DRY WEATHER AND
SLIGHTLY TO NEAR NORMAL TEMPERATURES BOTH DAYS. FOCUS TURNS TO
MEMORIAL DAY WEEKEND...WHERE THE 17.12Z GFS/ECMWF ARE IN GOOD
AGREEMENT IN EJECTING PIECES OF ENERGY OUT OF UPPER LEVEL LOW/TROUGH
OVER THE SOUTHWEST UNITED STATES INTO THE CENTRAL UNITED STATES.
BOTH THE 17.12Z GFS/ECMWF SHOW INCREASING LOW LEVEL JET/MOISTURE
TRANSPORT/CONVERGENCE AND LIFT/FORCING SATURDAY INTO SUNDAY INTO THE
FORECAST AREA. WILL CONTINUE TO TREND OF SHOWERS AND THUNDERSTORMS
SATURDAY INTO SUNDAY.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1245 PM CDT SUN MAY 17 2015

LOW PRESSURE LIFTING THROUGH THE REGION WILL PRODUCE SCATTERED
SHOWERS AND THUNDERSTORMS AND MVFR TO IFR CONDITIONS AT TIMES.
LOOK FOR A COLD FRONT TO SWEEP ACROSS THE TAF SITES THIS EVENING
WITH SOUTHWEST WINDS INCREASING TO 15 TO 17 KTS WITH GUSTS OF 25
TO 30 KTS POSSIBLE.


&&

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&

$$

SHORT TERM...DTJ
LONG TERM...DTJ
AVIATION...WETENKAMP




FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE



 .SHORT TERM...TONIGHT AND MONDAY
ISSUED AT 229 PM CDT SUN MAY 17 2015

THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW AN OCCLUDED
LOW PRESSURE SYSTEM SPINNING OVER THE EASTERN DAKOTAS.  SHORTWAVES
ARE ROTATING NORTHWARD AHEAD OF THIS OCCLUDED CYCLONE...THE
STRONGEST OF WHICH IS LOCATED OVER EASTERN IOWA.  A PWAT AXIS IS
MOVING ACROSS WISCONSIN EARLY THIS AFTERNOON...WHICH COMBINED WITH
MOISTURE CONVERGENCE...IS CONTRIBUTING TO SCATTERED SHOWER
DEVELOPMENT OVER CENTRAL WISCONSIN.  CLOUD COVER HAS SIGNIFICANTLY
SLOWED THE HEATING CURVE SO FAR TODAY...KEEPING ML CAPES BELOW 200
J/KG.  WITH SHOWER COVERAGE EXPECT TO INCREASE THROUGH THE
AFTERNOON...IT WILL BE TOUGH TO SEE MUCH OF AN INCREASE OF
INSTABILITY.  STILL THOUGH...RADAR ECHOES SUGGEST SOME THUNDERSTORMS
WILL BE POSSIBLE...AND ANY STORMS COULD BRING DOWN STRONG WINDS FROM
ALOFT.  WILL HAVE TO KEEP A MENTION OF ISOLATED DAMAGING WINDS
THROUGH EARLY THIS EVENING. OTHERWISE...THE LATEST HRRR CONGEALS THE
SHOWER ACTIVITY INTO BAND AND PROGRESSES IT ACROSS THE FORECAST AREA
FOR THE REST OF THE AFTERNOON.

TONIGHT...LOW PRESSURE WILL MOVE EAST ACROSS NORTHERN
MINNESOTA...WHILE A COLD FRONT WILL PUSH EAST THROUGH ALL BUT FAR
EASTERN WISCONSIN OVERNIGHT.  THOUGH SHORTWAVE ENERGY WILL BE
ROTATING NORTHEAST OVER NORTHWEST WISCONSIN THROUGH THE
EVENING...CONCERNED THAT STRONG DRYING AND INCREASING CAPPING IN THE
MID-LEVELS WILL EVEN FURTHER LIMIT THUNDERSTORM POTENTIAL FOR THE
FIRST COUPLE HOURS IN THE EVENING.  WILL KEEP A MENTION OF ISOLATED
DAMAGING WINDS THROUGH 02Z IN CASE SOME THUNDERSTORMS MAKE A RUN
INTO N-C WISCONSIN FROM MINNESOTA.  ONCE THE THREAT OF STORMS ENDS...MODELS
SHOW CLEARING TAKING PLACE UNTIL LOW CLOUDS FLOOD EAST BEHIND THE
COLD FRONT LATE TONIGHT.  LOW TEMPS NEAR 60 OVER THE EAST...BUT
COOLING TO NEAR 50 OVER THE WEST.

MONDAY...OCCLUDED LOW PRESSURE WILL BE WEAKENING AS IT MOVES TO THE
EAST ACROSS LAKE SUPERIOR.  WEST WINDS ON THE SOUTHERN FLANK OF THE
LOW WILL BE COLD ADVECTING THROUGH THE DAY...WHILE PUSHING IN WRAP
AROUND MOISTURE.  SHOULD SEE AMPLE CLOUD COVER OVER CENTRAL AND
NORTH-CENTRAL WISCONSIN THROUGH THE DAY...BUT EAST-CENTRAL WISCONSIN
WILL LIKELY SEE SOME SUN IN THE MORNING BEFORE CLOUDS INCREASE IN
THE AFTERNOON.  WITH THE SUNSHINE...TEMPS SHOULD WARM TO NEAR 70 IN
THE EAST...BUT ONLY INTO THE MID AND UPPER 50S OVER THE WEST.

.LONG TERM...MONDAY NIGHT THROUGH SUNDAY
ISSUED AT 229 PM CDT SUN MAY 17 2015

MUCH COOLER TEMPERATURES FOR THE FIRST HALF OF THE WORK WEEK...DRY
AND MILDER CONDITIONS FOR THE LATTER HALF...AND A POSSIBLE RETURN
TO WET WEATHER LATER IN THE MEMORIAL DAY WEEKEND...ARE THE MAIN
FCST CONCERNS.

THE REMNANTS OF THE UPPER LOW WILL TRACK ACROSS NORTHERN LAKE SUPERIOR
ON MONDAY NIGHT...FOLLOWED BY A S/W TROF PASSING NORTH OF WI ON TUESDAY.
UNSEASONABLY COLD AIR (H8 TEMPS -8 TO -10 C) WILL FLOW INTO THE REGION
ON NNW WINDS...SETTING THE STAGE FOR SOME LAKE-ENHANCED SHOWERS OVER
NC WI. LOW-LEVEL TEMPS AND THICKNESSES SUPPORT A MIX THEN CHANGEOVER
TO SNOW LATE MONDAY NIGHT INTO TUESDAY MORNING...WITH LITTLE OR NO
ACCUMULATION EXPECTED. ANY LINGERING PCPN SHOULD END TUESDAY AFTERNOON
AS CANADIAN HIGH PRESSURE BUILDS INTO THE REGION.

HIGH PRESSURE WILL COVER THE AREA TUESDAY NIGHT INTO WEDNESDAY. STILL
EXPECTING FROST TUESDAY NIGHT...BUT GETTING A LITTLE CONCERNED ABOUT
THE POSSIBILITY OF THICKER HIGH LEVEL CLOUDS...DUE TO THE PRESENCE
OF A STRONG JET STREAK OVER THE REGION. RIGHT NOW...HAVE JUST
BUMPED UP CLOUD COVER A BIT OVER C/EC WI...BUT KEPT MOSTLY CLEAR
SKIES OVER NORTHERN WI. WILL CONTINUE TO CARRY WIDESPREAD FROST OR
FREEZE CONDITIONS OVER NORTHERN WI...AND PATCHY FROST OVER MOST OF
C/EC WI.

A WEAK BACK DOOR COLD FRONT WILL SAG THROUGH THE FORECAST AREA THURSDAY
INTO THURSDAY NIGHT...BUT WILL NOT HAVE ANY MOISTURE TO WORK WITH...SO
DRY WEATHER WILL PREVAIL. BEHIND THE FRONT...CANADIAN HIGH PRESSURE
WILL REESTABLISH ITSELF OVER THE WESTERN GREAT LAKES...AND IS EXPECTED
TO LINGER INTO SATURDAY. ABUNDANT SUNSHINE SHOULD BRING A RETURN TO
NEAR NORMAL TEMPERATURES FOR THE LATTER HALF OF THE WEEK.

AN UPPER TROF...LOW PRESSURE SYSTEM AND ASSOCIATED COLD FRONT WILL
IMPACT THE REGION FROM SATURDAY NIGHT INTO SUNDAY. GULF MOISTURE
IS EXPECTED TO FLOW INTO THE REGION AHEAD OF THE FRONT...WITH
PRECIPITABLE WATER VALUES REACHING 1.00-1.25 INCHES. HAVE RAMPED
POPS UP TO LIKELY FOR SUNDAY. THE ECMWF PULLS MOST OF THE PCPN OUT
OF THE REGION SUNDAY EVG...WHILE THE GFS HANGS ONTO SIGNIFICANT
QPF INTO MEMORIAL DAY...SO FCST CONFIDENCE WANES BEYOND SUNDAY.
&&

.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1215 PM CDT SUN MAY 17 2015

COMPLICATED WEATHER SCENARIO UNFOLDING TODAY AS LOW PRESSURE
MOVES NORTHEAST OVER MINNESOTA...AND WARM FRONT LIFTS NORTH OVER
CENTRAL WISCONSIN. CIGS WITHIN A MOISTURE LADEN AIRMASS WILL
SLOWLY IMPROVE THIS AFTERNOON AS SHOWERS MOVE IN FROM THE WEST.
WITH FURTHER DAYTIME HEATING...THUNDERSTORMS REMAIN POSSIBLE MID-AFTERNOON
INTO THE EVENING AHEAD OF A COLD FRONT...WITH POTENTIAL FOR
DAMAGING WINDS WITHIN ANY STORMS. THE STORMS SHOULD DISSIPATE BY
MID-EVENING AND SKIES SHOULD PARTIALLY CLEAR INTO THE OVERNIGHT
PERIOD. THEN A COLD FRONT WILL MOVE THROUGH THE REGION LATE
TONIGHT. MVFR CLOUDS WILL RETURN INTO CENTRAL AND NORTH- CENTRAL
WISCONSIN BEHIND THE FRONT AND LINGER THROUGH THE END OF THE TAF
PERIOD.
&&

.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM.....MPC
LONG TERM......KIECKBUSCH
AVIATION.......MPC







AREA FORECAST DISCUSSION

NWS TUCSON AZ

 930 PM MST MON MAY 18 2015

.SYNOPSIS...A WEATHER SYSTEM PASSING NORTH OF THE AREA WILL DROP
DAYTIME TEMPERATURES A FEW DEGREES FOR TUESDAY. TEMPERATURES WILL
REBOUND WEDNESDAY AND THURSDAY BEFORE DROPPING BACK DOWN TO BELOW
NORMAL READINGS BY SATURDAY. OTHERWISE...PERIODS OF GUSTY WINDS CAN
BE ANTICIPATED THIS WEEK AS WEATHER SYSTEMS PASS THROUGH THE REGION.

&&

.DISCUSSION...ISOLATED VERY LIGHT SHOWERS OR VIRGA WERE STILL
OCCURRING ACROSS ERN PIMA ...GRAHAM AND GREENLEE COUNTIES THIS
EVENING. EVENING RUNS OF THE HRRR INDICATE THAT THESE LIGHT
SHOWERS/VIRGA WILL CONTINUE TO MOVE NNE AND MOSTLY OUT OF THE AREAS
NE OF TUCSON BY MIDNIGHT. SHORT WAVE ROTATING THRU BROAD UPPER LEVEL
TROFINESS OVER THE WRN CONUS WILL LIFT NE AWAY FROM THE AREA
TONIGHT. DRY...COOLER AND NOT AS WINDY ON TUESDAY. WARMER WEDNESDAY
WITH HIGHS SIMILAR TO TODAY THEN ANOTHER STORM SYSTEM WILL IMPACT
THE AREA THURSDAY AND FRIDAY WITH STRONG GUSTY WINDS BOTH DAYS AND
COOLER TEMPERATURES. ALL OF THIS WILL KEEP BELOW NORMAL TEMPERATURES
ACROSS MOST OF THE AREA FOR THE REMAINDER OF THE WEEK.

&&

.AVIATION...VALID THRU 20/06Z. SCT-BKN CLOUDS 12-15K FT DISSIPATING
AFTER 19/08Z BECOMING CLEAR BY 19/10Z. A FEW CUMULUS CLOUDS OVER THE
MOUNTAINS AGAIN AFTER 19/20Z. SW SFC WINDS GENERALLY LESS THAN 10
KTS OR LESS OVERNIGHT. SW WINDS REDEVELOPING TUESDAY AFTERNOON 10-15
KTS WITH GUSTS TO 25 KT. AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.

&&

.FIRE WEATHER...ACTIVE WEATHER PATTERN WILL CONTINUE THROUGH THE
COMING WEEKEND WITH SEVERAL WINDY PERIODS. LIGHTER WINDS AND COOLER
TEMPERATURES EXPECTED TUESDAY AND WEDNESDAY HOWEVER DEWPOINTS WILL
BE LOWER WITH SINGLE DIGIT MIN RHS BECOMING FAIRLY WIDESPREAD ACROSS
LOWER ELEVATIONS OF ZONES 151 AND 152 BY WEDNESDAY AFTERNOON.

YET ANOTHER UPPER LOW WILL APPROACH CALIFORNIA LATER WEDNESDAY WITH
AN ASSOCIATED UPPER LEVEL DISTURBANCE PASSING ACROSS THE AREA LATE
THURSDAY RESULTING IN WINDS SIMILAR TO OR SLIGHTLY STRONGER THAN
TODAY WITH LOWER HUMIDITY LEVELS FOR SPOTTY RED FLAG CONDITIONS
SOUTHERN PORTIONS OF ZONES 151-152. THEN MODELS CURRENTLY INDICATE
THE UPPER LOW WILL MOVE OVER NORTHERN ARIZONA FRIDAY FOR EVEN
STRONGER WINDS. IF THIS COMES TO PASS WINDS WILL BE EVEN STRONGER
FOR MORE WIDESPREAD CRITICAL CONDITIONS ESPECIALLY ZONE 152. BY THE
END OF A WEEK OF LOW RH LEVELS AND BREEZINESS...FUELS WILL BE MORE
RECEPTIVE AS 10 AND 100 HOUR FUELS SHOULD BECOME QUITE DRY WITH THE
CURED GRASS READY TO GO ANY AFTERNOON.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...NONE

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON



AREA FORECAST DISCUSSION

NWS RENO NV

 1032 PM PDT MON MAY 18 2015

.UPDATE...
SHOWERS HAVE INCREASED THIS EVENING ALONG A SUSANVILLE TO PYRAMID
LAKE TO LOVELOCK LINE AND ARE MOVING SOUTH. THESE SHOWERS HAVE
ACTUALLY INCREASED IN INTENSITY THE LAST HOUR, AND EXPECT THESE TO
CONTINUE THROUGH AT LEAST MIDNIGHT BEFORE GRADUALLY WANING AS THEY
MOVE SOUTH. AS A RESULT, HAVE INCREASED POPS FOR THE SIERRA FRONT
AND TAHOE REGION AS WELL AS HIGHWAY 50 EAST THROUGH FALLON. HRRR
SHOWS THE SHOWERS DIMINISHING ABOUT THIS TIME WHICH SEEMS
REASONABLE, BUT CONFIDENCE IN THE MODEL IS LOW. IT HAS PERFORMED
RATHER POORLY THE LAST COUPLE NIGHTS AFTER CONVECTIVE INITIATION
AND BEYOND 3 HOURS. AT THIS POINT THOUGH, IT SEEMS REASONABLE AND
IS SIMILAR TO MY BEST GUESS SO WILL RUN WITH IT.

RAINFALL AMOUNTS WITH THE SHOWERS SHOULD AVERAGE AROUND A TENTH OF
AN INCH, BUT LOCALLY HIGHER AMOUNTS TO 1/3 INCH ARE POSSIBLE. AS
OF THIS WRITING THE HEAVIEST RAINS LOOK MOST LIKELY TO OCCUR IN
SPANISH SPRINGS, HIDDEN VALLEY AND AROUND LOCKWOOD. WALLMANN

&&

.AVIATION...
SCATTERED SHOWERS CONTINUE THIS EVENING NEAR AND SOUTH OF I-80.
CIGS 3-4000 FEET WILL OCCUR IN THE SHOWERS THRU 10Z FOR
KTVL/KTRK/KRNO/KCXP. LOW CLOUD DECKS AND RAIN SHOWERS WILL CREATE
SOME MOUNTAIN OBSCURATION IN THE SIERRA. GENERALLY LIGHT WEST
WINDS WITH THE CHANCE OF GUSTS TO AROUND 30 KTS NEAR
THUNDERSTORMS. A FEW MORE SHOWERS ARE EXPECTED TUESDAY, BUT
COVERAGE IS EXPECTED TO BE LESS THAN THE LAST TWO DAYS.
TOLBY/WALLMANN


&&

.PREVIOUS DISCUSSION... /ISSUED 300 PM PDT MON MAY 18 2015/

SYNOPSIS...
LOW PRESSURE ALOFT WILL REMAIN OVER CALIFORNIA AND NEVADA THROUGH
THE END OF THE WORK WEEK, BRINGING BELOW AVERAGE TEMPERATURES
AND ROUNDS OF SHOWERS AND THUNDERSTORMS, MAINLY IN THE AFTERNOONS
AND EVENINGS. PRECIPITATION CHANCES DECREASE OVER THE MEMORIAL
DAY WEEKEND ALTHOUGH A FEW SHOWERS AND THUNDERSTORMS WILL STILL
BE POSSIBLE.

SHORT TERM...
A TROUGH OF LOW PRESSURE REMAINS OVER THE WEST. AN UPPER
DISTURBANCE OVER SOUTHEAST CALIFORNIA AND SOUTHERN NEVADA IS
ROTATING AROUND THE TROUGH, BRINGING INCREASED DIVERGENCE ALOFT
AND HELPING TO INITIATE SHOWERS AND THUNDERSTORMS OVER SOUTHERN
AND EASTERN NEVADA.

FOR NORTHEAST CALIFORNIA AND WESTERN NEVADA, ACTIVITY IS RESTRICTED
EARLY THIS AFTERNOON WITH THE BEST FORCING SOUTH AND EAST OF THE
AREA. HOWEVER, SCATTERED SHOWERS SHOULD STILL DEVELOP GIVEN THE
MOIST AND WEAKLY UNSTABLE ATMOSPHERE, ESPECIALLY FOR EASTERN
CALIFORNIA AND FAR WESTERN NEVADA WHERE THE HRRR AND NAM SHOW A
LIGHT WESTERLY FLOW OFF THE SIERRA (TO AID LOW LEVEL CONVERGENCE
AND UPWARD MOTION) INTO THE EVENING. AS FAR AS THUNDERSTORMS, LOW
FREEZING LEVELS AND WEAK INSTABILITY MAKE IT HARD TO RULE OUT
BRIEF, ISOLATED CELLS. ANY STORMS THIS EVENING WILL BE WEAK WITH
THE MAIN THREAT BEING LIGHTNING AND LARGE QUANTITIES OF SMALL,
SOFT HAIL (GRAUPEL TECHNICALLY).

LATE TONIGHT, THE HRRR AND LESS-SO THE GFS AND NAM ARE INDICATING
WRAP-AROUND PRECIPITATION OVER NORTHEAST CALIFORNIA AND NORTHWEST
NEVADA AS THE UPPER LOW ADVANCES INTO EASTERN NEVADA. WITH THIS IN
MIND, I HAVE LEFT IN SCATTERED SHOWERS NORTH OF RENO AND FALLON
WITH ISOLATED COVERAGE ELSEWHERE.

TUESDAY, THE REGION IS BETWEEN UPPER WAVES. HOWEVER, MOISTURE
REMAINS IN PLACE AND BETTER HEATING IS POSSIBLE WITH LITTLE UPPER
FORCING ALLOWING FOR LESS/THINNER CLOUD COVER IN THE MORNING. THIS
SHOULD FACILITATE SCATTERED SHOWERS IN THE AFTERNOON AND EVENING,
WITH A LOW CHANCE FOR THUNDERSTORMS.

WEDNESDAY, THE BEST UPPER FORCING OF THE SHORT TERM IS EXPECTED AS
ANOTHER DISTURBANCE RELOADS THE SOUTHWEST CONUS TROUGH. THE
DISTURBANCE IS EXPECTED TO MOVE FROM SOUTH TO NORTH THROUGH
CALIFORNIA WITH THE BEST FORCING IN THE AFTERNOON AND EVENING.
WITH THIS IN MIND, I HAVE BUMPED POP A BIT MORE OVER MUCH OF FAR
WESTERN NEVADA AND EASTERN CALIFORNIA WITH NUMEROUS SHOWERS EXPECTED
BY AFTERNOON. WITH THE FORCING, I WOULD EXPECTED AT LEAST ISOLATED
THUNDERSTORMS WITH HIGHER COVERAGE POSSIBLE IF WE CAN GET DECENT
MORNING HEATING (CLEARER SKIES). SNYDER

LONG TERM...THURSDAY THROUGH MONDAY...

BY THURSDAY AN AREA OF LOW PRESSURE WILL AGAIN BE ALONG THE
CENTRAL CALIFORNIA COAST. THIS WILL CONTINUE TO BRING WIDESPREAD
CHANCES OF PRECIPITATION, ISOLATED THUNDERSTORMS, AND BELOW
AVERAGE DAYTIME TEMPERATURES. THURSDAY CURRENTLY LOOKS TO BE THE
WETTEST DAY WITH MOISTURE WRAPPING AROUND THE LOW PRESSURE AND
BANKING AGAINST THE SIERRA FROM THE EAST. RELATIVELY DEEP MOISTURE
AND UPSLOPE FLOW COULD ALLOW SOME AREAS TO PICK UP ANOTHER ROUND
OF SIGNIFICANT PRECIPITATION, ESPECIALLY IN THE CENTRAL SIERRA.

BY FRIDAY THE LOW PRESSURE WILL MOVE INTO SOUTHERN NEVADA
BRINGING NORTHERLY FLOW TO THE AREA. THIS WILL DECREASE THE CHANCE
OF SIGNIFICANT QPF IN THE SIERRA, BUT WILL STILL ALLOW WIDESPREAD
PRECIPITATION TO WESTERN NEVADA AND THE SIERRA.

FOR THE HOLIDAY WEEKEND...

CHANCES FOR THUNDERSTORMS WILL BE ON THE DECREASE BY THE HOLIDAY
WEEKEND AS THE LOW PRESSURE MOVES INTO THE ROCKIES, BUT WITH SOME
RESIDUAL MOISTURE AND INCREASING TEMPERATURES THERE IS STILL A
SLIGHT CHANCE OF THUNDERSTORM ACTIVITY IN SIERRA AND WESTERN
NEVADA THROUGH THE WEEKEND. SIGNIFICANT MODEL DISCREPANCIES EXIST
BY THE WEEKEND SO FORECAST CONFIDENCE IS CURRENTLY LOW ON THE
BEST AREA FOR THUNDERSTORM CHANCES.

EXPECT A WARMING TREND THROUGH THE WEEKEND WITH DAYTIME
TEMPERATURES RIGHT AROUND SEASONAL AVERAGES WITH MID 70`S IN
WESTERN NEVADA AND MID 60`S IN THE SIERRA. BY MONDAY WESTERN
NEVADA VALLEYS COULD HIT 80 WITH SIERRA VALLEYS REACHING 70.
TOLBY

AVIATION...

SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE EXPECTED
THROUGHOUT THE SIERRA AND WESTERN NEVADA THROUGH THIS EVENING.
LOW CLOUD DECKS AND RAIN SHOWERS WILL CREATE SOME MOUNTAIN
OBSCURATION IN THE SIERRA. GENERALLY LIGHT WEST WINDS WITH THE
CHANCE OF GUSTS TO AROUND 30 KTS NEAR THUNDERSTORMS. TOLBY

&&

.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&

$$

FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)




AREA FORECAST DISCUSSION

NWS COLUMBIA SC

 327 AM EDT TUE MAY 19 2015

.SYNOPSIS...
EXPECT SCATTERED MAINLY AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS TODAY AHEAD OF A WEAK FRONT THAT WILL CROSS THE AREA
TONIGHT. THE FRONT WILL STALL JUST TO OUR SOUTH
WEDNESDAY. AN UPPER DISTURBANCE AND SURFACE WAVE WILL MOVE
THROUGH THURSDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...

MORNING WATER VAPOR IMAGERY IS SHOWING THE UPPER RIDGE AXIS BREAKING
DOWN AS IT GIVES WAY TO SHORTWAVE ENERGY MOVING THROUGH THE
OHIO/MISSISSIPPI VALLEYS.  SURFACE ANALYSIS INDICATES BROAD HIGH
PRESSURE ACROSS THE CAROLINAS AND SOUTHEAST WITH A COLD FRONT
EXTENDING FROM NEAR DETROIT SOUTHWESTWARD TO SOUTHERN ILLINOIS INTO
NORTHERN TEXAS.  EARLIER CONVECTION HAS DIMINISHED WITH THE LOSS OF
HEATING AND THE DEBRIS CLOUDS ASSOCIATED WITH THAT CONVECTION ARE
ALSO DIMINISHING WHICH SHOULD ALLOW FOR SOME SUNSHINE THIS MORNING.

THE COLD FRONT OVER THE OHIO VALLEY WILL CONTINUE TO PUSH EASTWARD
TODAY AS SHORTWAVE ENERGY PUSHING INTO NEW ENGLAND BY THIS EVENING
AND THE COLD FRONT CROSSES OUR REGION.  PWAT VALUES INCREASE TO
NEARLY 1.8 JUST AHEAD OF THE FRONT THIS AFTERNOON PROVIDING PLENTY
OF MOISTURE FOR CONVECTION WHILE A PRE-FRONTAL SURFACE TROUGH ALSO
COULD PROVIDE A FOCUS FOR CONVECTION. SOME LIMITING FACTORS TODAY
INCLUDE WEAK CONVERGENCE FORECAST ALONG THE FRONT AS WINDS AHEAD OF
THE FRONT ALREADY WILL BE FROM THE WEST AND 850MB FLOW IS ALSO
WESTERLY COMING ACROSS THE MOUNTAINS WHICH USUALLY INHIBITS
WIDESPREAD CONVECTION.  MODERATE INSTABILITY IS FORECAST WITH LIFTED
INDEX VALUES AROUND -5C BUT SHEAR CONTINUES TO BE WEAK. MOST OF THE
NWP GUIDANCE INCLUDING THE HIGH RESOLUTION MODELS FOCUS THE
CONVECTION ACROSS SOUTHERN AND CENTRAL NORTH CAROLINA AND DEVELOP IT
EASTWARD THROUGH THE AFTERNOON THEN EXPANDING TO THE COASTAL REGIONS
OF NC/SC. THIS LOGICALLY MAKES SENSE AS THE BETTER UPPER LEVEL
SUPPORT WILL BE FURTHER TO THE NORTH AND THE SEA BREEZE COULD BE
ANOTHER TRIGGER FOR CONVECTION OR ENHANCE CONVECTION MOVING INTO THE
COASTAL AREAS LATE IN THE DAY. FOR THESE REASONS WILL CONTINUE WITH
ONLY CHANCE POPS WITH THE HIGHEST POPS ACROSS THE NORTHERN AND
EASTERN MIDLANDS AND PEE DEE REGION...AND COVERAGE COULD BECOME A
BIT MORE WIDESPREAD IF STORMS BECOME MULTICELLULAR WITH NEW
CONVECTION FORMING ON OUTFLOW BOUNDARIES.  CONVECTION MAY LINGER
INTO THE EVENING HOURS ALONG AND AHEAD OF THE FRONT ACROSS THE
EASTERN AND SOUTHERN MIDLANDS BUT SHOULD END BY 06Z ACROSS THE AREA.

TEMPERATURES TODAY WILL AGAIN BE WARM IN THE UPPER 80S TO LOWER 90S
WITH LOWS TONIGHT RANGING FROM THE MID 60S NORTHERN MIDLANDS TO
LOWER 70S SOUTHEASTERN MIDLANDS.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
MODELS INDICATE THE FRONT WILL STALL NEAR THE CSRA AND SOUTHERN
MIDLANDS OR JUST TO THE SOUTH WEDNESDAY. DIURNAL SHOWER AND
THUNDERSTORM ACTIVITY WILL FAVOR THOSE REGIONS. DRIER AIR
ENTERING THE NORTHERN FA BEHIND THE FRONT EXPECTED TO PRECLUDE
CONVECTION THERE. MODELS DEVELOP A SURFACE WAVE OF LOW PRESSURE
ALONG THE STALLED FRONT...IN RESPONSE TO APPROACHING UPPER
ENERGY...WHICH SLOWLY TRACKS EAST ACROSS THE FA LATE WEDNESDAY
NIGHT AND THURSDAY. ACCEPTED GUIDANCE BLEND OF CHANCE POPS.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
MODELS REMAIN IN GOOD AGREEMENT WITH SOME MINOR TIMING AND
INTENSITY DIFFERENCES THROUGH THE WEEKEND AND INTO NEXT WEEK.
ON FRIDAY HIGH PRESSURE CROSSING THE CENTRAL GREAT LAKES WILL
USHER SLIGHTLY COOLER AND DRIER AIR SOUTHWARD AND INTO THE REGION.
THE HIGH WILL TRACK OFF THE NEW ENGLAND COAST ON SATURDAY ALLOWING
MOIST SOUTHERLY FLOW TO BEGIN RETURNING TO THE REGION. THIS WILL
ALLOW LOW CHANCES OF MAINLY DIURNAL SHOWERS AND THUNDERSTORMS TO
RETURN TO THE AREA. TEMPERATURES THROUGH THE LONG TERM WILL BE
NEAR TO SLIGHTLY ABOVE NORMAL.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...

VFR CONDITIONS EXPECTED THROUGH THE PERIOD EXCEPT RESTRICTIONS IN
FOG AT AGS.

EVENING CONVECTION HAS COME TO AN END BUT RAIN COOLED AIR HAS
ALLOWED FOG TO DEVELOP AT AGS AND WILL LIKELY CONTINUE TO BE AN
ISSUE THROUGH 13Z WITH VSBYS RANGING BETWEEN 3SM AND 1/2SM.
ELSEWHERE...A WEAK LOW LEVEL JET IS HELPING TO KEEP THE SURFACE
WINDS UP JUST ENOUGH TO PREVENT FOG DEVELOPMENT THUS FAR. DO NOT
EXPECT MUCH FOG OUTSIDE OF AGS ALTHOUGH HRRR GUIDANCE AND NAM MOS
HINTING AT SOME POSSIBLE STRATUS CLOUD FORMATION AFTER 09Z IN
AREAS THAT RECEIVED RAINFALL SO HAVE INCLUDED A BRIEF PERIOD OF
MVFR CIGS TO ACCOUNT FOR THAT AT CAE/CUB.

HEATING AND SOME CONVERGENCE ASSOCIATED WITH A PRE-FRONTAL TROUGH
AND AN APPROACHING COLD FRONT SHOULD SUPPORT THUNDERSTORMS DURING
THE DAY TUESDAY. THE MODELS DISPLAY THE GREATER CONVERGENCE AND
INSTABILITY NORTH AND EAST OF THE TERMINALS AND WE EXPECT
SCATTERED THUNDERSTORM COVERAGE. THE CHANCE OF THUNDERSTORMS IS
TOO LOW TO INCLUDE IN THE TERMINAL FORECASTS AT THIS TIME THOUGH
OGB IS PROBABLY MOST LIKELY TO BE IMPACTED LATE THIS AFTERNOON
INTO EARLY EVENING.

EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE IN MAINLY
SCATTERED AFTERNOON AND EVENING THUNDERSTORMS.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.

&&

$$
99




AREA FORECAST DISCUSSION

NWS COLUMBIA SC

 155 AM EDT TUE MAY 19 2015

.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO WEAKEN AND SHIFT EAST TODAY WHILE
ATMOSPHERIC MOISTURE INCREASES OVER THE REGION. A WEAK FRONT WILL
CROSS THE AREA THIS AFTERNOON AND EVENING BRINGING SHOWERS AND
THUNDERSTORMS. THE FRONT WILL REMAIN JUST SOUTH OF THE REGION
THROUGH THE WEEKEND WITH PARTLY CLOUDY SKIES AND LOW CHANCES OF
MAINLY AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS.

&&

.NEAR TERM /THROUGH 6AM/...
EVENING CONVECTION CONTINUES TO WANE WITH THE STABILIZATION OF THE
ATMOSPHERE. HIGH PRESSURE OFF THE SOUTHEAST COAST WILL WEAKEN
TONIGHT. MOISTURE WILL REMAIN ELEVATED WITH PWAT VALUES AROUND 1.6
INCHES AHEAD OF AN APPROACHING FRONTAL BOUNDARY. UPPER LEVEL
CLOUDS AND HIGH DEW POINTS WILL KEEP LOWS ABOVE NORMAL...IN THE
UPPER 60S.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
UPPER LEVEL RIDGE WILL BEGIN THE DAY ALONG THE COAST AND CONTINUE
TRACKING EASTWARD INTO THE ATLANTIC BASIN TUESDAY WITH A ZONAL
PATTERN FOR TUESDAY NIGHT THROUGH WEDNESDAY NIGHT. THE WEAK
FRONTAL BOUNDARY WILL MOVE THROUGH THE FORECAST AREA DURING THE
AFTERNOON HOURS TRIGGERING SHOWERS AND THUNDERSTORMS FOR THE LATE
MORNING THROUGH EVENING HOURS. PWAT VALUES WILL BE BETWEEN 1.6 AND
1.7 INCHES THROUGH MUCH OF TUESDAY AND WITH WEAK FLOW ALOFT COULD
LEAD TO SOME LOCALLY HEAVY RAINFALL. ONE CONCERN WILL BE THE LOW
LEVEL WINDS WHICH WILL TURN NORTHWESTERLY DURING THE LATE MORNING
AND EARLY AFTERNOON HOURS...WITH THIS DOWNSLOPING WIND CONVECTION
IS TYPICALLY SUPPRESSED ESPECIALLY ACROSS THE WESTERN MIDLANDS. AS
SUCH HAVE ADJUSTED POPS TO ACCOUNT FOR THE DOWNSLOPING WITH HIGHER
POPS IN THE CENTRAL AND EASTERN MIDLANDS. FRONT WILL STALL JUST
SOUTH OF THE AREA TUESDAY NIGHT THROUGH WEDNESDAY NIGHT. THIS WILL
KEEP MOISTURE AND INSTABILITY GREATEST OVER THE SOUTHERN MIDLANDS
AND CSRA SO HAVE KEPT SLIGHT CHANCE POPS FOR THOSE AREAS TUESDAY.
SEVERE THREAT THROUGH THE SHORT TERM REMAINS LOW WITH THE MAIN
POTENTIAL FROM DAMAGING WIND GUSTS. DAYTIME HIGH TEMPERATURES WILL
BE IN THE UPPER 80S TO LOWER 90S WITH OVERNIGHT LOWS IN THE MIDDLE
TO UPPER 60S.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
MODELS REMAIN IN GOOD AGREEMENT WITH SOME MINOR TIMING AND
INTENSITY DIFFERENCES THROUGH THE WEEKEND AND INTO NEXT WEEK.
FRONTAL BOUNDARY WILL CONTINUE TO SHEAR APART SOUTH OF THE
FORECAST AREA WITH A WEAK AREA OF LOW PRESSURE EXPECTED TO CROSS
THE REGION THURSDAY AND THURSDAY NIGHT. ON FRIDAY HIGH PRESSURE
CROSSING THE CENTRAL GREAT LAKES WILL USHER SLIGHTLY COOLER AND
DRIER AIR SOUTHWARD AND INTO THE REGION. THE HIGH WILL TRACK OFF
THE NEW ENGLAND COAST ON SATURDAY ALLOWING MOIST SOUTHERLY FLOW TO
BEGIN RETURNING TO THE REGION. THIS WILL ALLOW LOW CHANCES OF
MAINLY DIURNAL SHOWERS AND THUNDERSTORMS TO RETURN TO THE AREA.
TEMPERATURES THROUGH THE LONG TERM WILL BE NEAR TO SLIGHTLY ABOVE
NORMAL.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
VFR CONDITIONS EXPECTED THROUGH THE PERIOD EXCEPT RESTRICTIONS IN
FOG AT AGS.

EVENING CONVECTION HAS COME TO AN END BUT RAIN COOLED AIR HAS
ALLOWED FOG TO DEVELOP AT AGS AND WILL LIKELY CONTINUE TO BE AN
ISSUE THROUGH 13Z WITH VSBYS RANGING BETWEEN 3SM AND 1/2SM.
ELSEWHERE...A WEAK LOW LEVEL JET IS HELPING TO KEEP THE SURFACE
WINDS UP JUST ENOUGH TO PREVENT FOG DEVELOPMENT THUS FAR. DO NOT
EXPECT MUCH FOG OUTSIDE OF AGS ALTHOUGH HRRR GUIDANCE AND NAM MOS
HINTING AT SOME POSSIBLE STRATUS CLOUD FORMATION AFTER 09Z IN
AREAS THAT RECEIVED RAINFALL SO HAVE INCLUDED A BRIEF PERIOD OF
MVFR CIGS TO ACCOUNT FOR THAT AT CAE/CUB.

HEATING AND SOME CONVERGENCE ASSOCIATED WITH A PRE-FRONTAL TROUGH
AND AN APPROACHING COLD FRONT SHOULD SUPPORT THUNDERSTORMS DURING
THE DAY TUESDAY. THE MODELS DISPLAY THE GREATER CONVERGENCE AND
INSTABILITY NORTH AND EAST OF THE TERMINALS AND WE EXPECT
SCATTERED THUNDERSTORM COVERAGE. THE CHANCE OF THUNDERSTORMS IS
TOO LOW TO INCLUDE IN THE TERMINAL FORECASTS AT THIS TIME THOUGH
OGB IS PROBABLY MOST LIKELY TO BE IMPACTED LATE THIS AFTERNOON
INTO EARLY EVENING.

EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE IN MAINLY
SCATTERED AFTERNOON AND EVENING THUNDERSTORMS.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.

&&

$$




AREA FORECAST DISCUSSION

NWS GRAY ME

 535 AM EDT TUE MAY 19 2015

.SYNOPSIS...
SHOWERS ASSOCIATED WITH A WARM FRONT WILL SPREAD ACROSS THE REGION
THIS MORNING. SHOWERS AND THUNDERSTORMS WILL DEVELOP THIS
AFTERNOON AND EVENING AHEAD OF A COLD FRONT. A NORTHWEST FLOW
WILL DEVELOP BEHIND THE FRONT TONIGHT AND PROVIDE COOL BUT MOSTLY
QUIET WEATHER INTO THE WEEKEND.

&&

.NEAR TERM /TODAY/...
530AM UPDATE...
HAVE UPDATED HOURLY PRECIPITATION CHANCES BASED ON RECENT RADAR
TRENDS. MUCH OF THE AREA IS SEEING SHOWERS NOW EXCEPT THE
IMMEDIATE COAST. THIS WILL CHANGE SOON. BACK EDGE OF PRECIPITATION
MOVING INTO VERMONT NOW AND WILL REACH WESTERN NEW HAMPSHIRE
WITHIN THE NEXT 2 TO 3 HOURS.

ORIGINAL DISCUSSION...
AREA OF SHOWERS AND A FEW EMBEDDED THUNDERSTORMS IS MOVING THROUGH
THE HUDSON VALLEY EARLY THIS MORNING AND SHOULD ARRIVE IN NEW
HAMPSHIRE IN THE NEXT TWO HOURS BEFORE SPREADING EASTWARD ACROSS
THE REST OF NEW HAMPSHIRE AND WESTERN MAINE THIS MORNING. THIS
AREA OF PRECIPITATION IS ASSOCIATED WITH A WARM FRONT-LIKE
FEATURE IN THAT BEHIND IT DEWPOINTS ARE SURGING INTO THE MID 60S
WHILE THE COOL MARITIME AIR MASS AHEAD OF IT IS COOLER AND WITH
LOWER DEWPOINTS. BUT YOU WILL BE HARD PRESSED TO FIND A
NOTICEABLE WIND SHIFT OR PRESSURE TROUGH WITH IT. SUCH IS LIFE IN
NORTHERN NEW ENGLAND.

AREA OF RAIN WILL MOVE INTO THE MIDCOAST REGION OF MAINE LATE IN
THE MORNING AND PERSIST INTO THE AFTERNOON. WHILE NEW HAMPSHIRE
WILL SEE THE RAIN ENDING EARLIER IN THE MORNING. BREAKS IN THE
CLOUDS SHOULD ALLOW FOR PRETTY GOOD WARMING INTO THE MID TO UPPER
70S OVER WESTERN NEW HAMPSHIRE. THE COMBINATION OF THIS WARMING...
THE INCREASING LOW LEVEL MOISTURE... AND COOLING TEMPERATURES
ALOFT ASSOCIATED WITH A SHORTWAVE TROUGH WILL PROVIDE SUBSTANTIAL
INSTABILITY THIS AFTERNOON... PERHAPS THE BEST SEEN YET THIS
SEASON. CAPE APPROACHES OR EXCEEDS 1000 BY LATE THIS AFTERNOON AND
EARLY EVENING OVER VERMONT AND NEW HAMPSHIRE. JUST AS INSTABILITY
IS INCREASING... A COLD FRONT WILL BEGIN MOVING ACROSS NORTHERN
NEW ENGLAND FROM WEST TO EAST. THIS WILL PROVIDE LOW LEVEL
CONVERGENCE TO ADD LIFT TO THE EQUATION... AIDING IN THE
DEVELOPMENT OF THUNDERSTORMS. BEST INSTABILITY AND LIFT DOES NOT
ARRIVE UNTIL LATE IN THE DAY... SO THUNDERSTORM POTENTIAL SEEMS TO
BE MORE IN THE 4PM-8PM TIME PERIOD... WITH REMNANT STORMS LIKELY
MAINTAINING THEMSELVES THROUGH ELEVATED INSTABILITY THROUGH
MIDNIGHT TONIGHT.

MESOSCALE MODELS INCLUDING THE NAM AND HRRR INDICATING POTENTIALLY
TWO SEPARATE AREAS OF MORE WIDESPREAD THUNDERSTORM ACTIVITY LATE
THIS AFTERNOON. THE FIRST IS OVER THE NORTHERN ADIRONDACKS AND THE
SECOND OVER THE CATSKILLS... BOTH AREAS FIRING AS THE FRONT MOVES
THROUGH TO PROVIDE LIFT AND MAY BE ENHANCED DUE TO TERRAIN-BASED
INSTABILITY. IF THIS SCENARIO UNFOLDS... THEN THE NORTHERN AREA OF
THUNDERSTORMS WOULD MOVE EAST ACROSS VERMONT AND THE NORTHERN HALF
OF NEW HAMPSHIRE AND INTO NORTHWEST MAINE IN THE EVENING. THE
SOUTHERN CLUSTER WOULD MOVE EAST MAINLY INTO MASSACHUSETTS. HAVE
ORIENTED AFTERNOON/EVENING THUNDERSTORM CHANCES AS BEING GREATEST
IN THE NORTH WHERE THE MORE NORTHERN CLUSTER OF STORMS WOULD MOVE
ACROSS BUT HAVE MAINTAINED AT LEAST A CHANCE OF THUNDERSTORMS OVER
ALL OF NEW HAMPSHIRE AND EXTENDING INTO FAR WESTERN/NORTHERN
MAINE IN THE EVENING.

ONE FINAL INGREDIENT TO ADD TO THE MIX TODAY IS INCREASING WIND
SHEAR. BY EVENING... AROUND THE TIME THE FRONT WILL BE MOVING INTO
NEW HAMPSHIRE... WINDS ALOFT APPROACH 50 KT AT 700 MB WHILE
SURFACE WINDS ARE BROADLY LIGHT OUT OF THE SOUTH. THIS WILL
PROVIDE ENOUGH SPEED SHEAR TO PROVIDE STORM ORGANIZATION AND
SUPERCELL TYPE STRUCTURES. THIS MAKES SEVERE THUNDERSTORMS MORE
LIKELY... WITH DAMAGING WINDS AND HAIL BEING THE PRIMARY THREATS.
HOWEVER... GIVEN LOW LEVEL WINDS OUT OF THE SOUTH... CANNOT RULE
OUT THE POSSIBILITY OF AN ISOLATED TORNADO PARTICULARLY IN AREAS
WHERE LOW LEVEL WINDS ARE CHANNELED BY TERRAIN AND PRODUCE GREATER
LOCALIZED DIRECTIONAL SHEAR. HAVE MENTIONED THE THREAT OF DAMAGING
WINDS AND LARGE HAIL IN THE PUBLIC FORECAST FOR LATE THIS
AFTERNOON. HAVE ALSO ORIENTED HOURLY PRECIPITATION CHANCES TO
BETTER REFLECT THE IDEA THAT EARLY MORNING SHOWERS WILL MOVE EAST
BEFORE THE CHANCE OF THUNDERSTORMS ARRIVES LATE.

&&

.SHORT TERM /TONIGHT AND WEDNESDAY/...
COLD FRONT WILL PUSH EAST ACROSS THE REGION TONIGHT WITH
THUNDERSTORM ACTIVITY LIKELY LINGERING INTO THE EVENING...
POSSIBLY TO AROUND MIDNIGHT IN NORTHERN MAINE. COOLER AND DRIER
AIR WILL BE MOVING IN BEHIND THE COLD FRONT. COULD SEE SOME FOG
NEAR THE COAST BEFORE THE FRONT MOVES THROUGH AND BEGINS TO
MIX/DRY THINGS OUT. TEMPERATURES FALL INTO THE UPPER 40S AND LOW
50S.

WILL BE A COOLER DAY ON WEDNESDAY FOR MOST OF THE REGION. BUT ON
THE COAST IT MAY ACTUALLY BE A FEW DEGREES WARMER... A TYPICAL
RESULT OF A PASSING COLD FRONT AND A SHIFT TO OFFSHORE WINDS. HIGH
TEMPERATURES RANGE FROM THE MID 50S IN THE NORTH TO THE MID 60S
NEAR THE COAST. DEWPOINTS WILL BE FALLING INTO THE 30S WHICH WILL
MAKE IT DIFFICULT FOR ANY SHOWERS TO DEVELOP IN SPITE OF SOME LIFT
MOVING THROUGH WITH THE PASSING OF THE UPPER LEVEL TROUGH.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
A LARGE UPPER LEVEL TROUGH WILL DOMINATE THE FLOW ACROSS NEW
ENGLAND THROUGH THE WEEKEND. SEVERAL DISTURBANCES WILL ROTATE
AROUND THE TROUGH, HOWEVER, COOL DRY WEATHER WILL RULE FOR MUCH OF
THE PERIOD. A MOISTURE-STARVED FRONT DROPPING SOUTHWARD FROM
CANADA COULD BRING A FEW SHOWERS TO THE REGION FRIDAY. BEHIND THE
FRONT...TEMPERATURES WILL BE MAINLY IN THE 60S SATURDAY BUT SHOULD
START TO WARM INTO THE 70S MOST AREAS FOR SUNDAY AND MONDAY AS THE
TROUGH AXIS SLIDES EAST OF THE REGION. MODELS NOW DELAY NEXT
SIGNIFICANT PRECIPITATION UNTIL TUESDAY, ALLOWING FOR A VERY
PLEASANT HOLIDAY WEEKEND.

NOTE: THE FREEZE/FROST PROGRAM STARTS IN NORTHERN ZONES
THURSDAY MAY 21. LOW TEMPERATURES THURSDAY AND SATURDAY MORNINGS
WILL DROP NEAR OR BELOW FREEZING ACROSS NORTHERN ZONES AND MAY
REQUIRE FREEZE WARNINGS AND/OR FROST ADVISORIES.

&&

.AVIATION /07Z TUESDAY THROUGH SATURDAY/...
SHORT TERM...EARLY MORNING IFR/LIFR CONDITIONS WILL BEGIN
IMPROVING THIS MORNING EVEN AS AN AREA OF RAIN MOVES ACROSS THE
AREA. COULD SEE MVFR CEILINGS LINGER THROUGH MUCH OF THE DAY BUT
THERE IS A BETTER CHANCE THAT CONDITIONS WILL BREAK OUT TO VFR FOR
AT LEAST A FEW HOURS. THERE IS A CHANCE OF THUNDERSTORMS ACROSS
MUCH OF NEW HAMPSHIRE LATE THIS AFTERNOON INTO EARLY THIS EVENING.
LOW CLOUDS MAY MAKE A RETURN VISIT TO COASTAL MAINE EARLY THIS
EVENING BUT THE PASSING OF A COLD FRONT DURING THE NIGHT WILL
LIKELY IMPROVE CONDITIONS TO VFR EVENTUALLY.

LONG TERM...MAINLY VFR CONDITIONS EXPECTED.

&&

.MARINE...
SHORT TERM...SOUTHERLY FLOW INCREASES TODAY THEN SHIFTS TO THE
WEST TONIGHT BEHIND A COLD FRONT. WEST WINDS COULD GUST TO AROUND
20 KT ON WEDNESDAY.

LONG TERM...WITH MAINLY OFFSHORE FLOW...WINDS AND SEAS EXPECTED
TO REMAIN BELOW SCA CRITERIA. STRONGEST WINDS AND HIGHEST SEAS
SHOULD BE WELL OFFSHORE.

&&

.FIRE WEATHER...
MOIST AIR AND WIDESPREAD WETTING RAIN TODAY WILL KEEP FIRE DANGER
CONDITIONS LOW. DRY AIR MOVES IN BEHIND A COLD FRONT TONIGHT...
LEADING TO MUCH DRIER CONDITIONS WEDNESDAY INTO THE WEEKEND.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.

&&

$$

NEAR TERM...KIMBLE
SHORT TERM...KIMBLE
LONG TERM...JENSENIUS




AREA FORECAST DISCUSSION

NWS GRAY ME

 329 AM EDT TUE MAY 19 2015

.SYNOPSIS...
SHOWERS ASSOCIATED WITH A WARM FRONT WILL SPREAD ACROSS THE REGION
THIS MORNING. SHOWERS AND THUNDERSTORMS WILL DEVELOP THIS
AFTERNOON AND EVENING AHEAD OF A COLD FRONT. A NORTHWEST FLOW
WILL DEVELOP BEHIND THE FRONT TONIGHT AND PROVIDE COOL BUT MOSTLY
QUIET WEATHER INTO THE WEEKEND.

&&

.NEAR TERM /TODAY/...
AREA OF SHOWERS AND A FEW EMBEDDED THUNDERSTORMS IS MOVING THROUGH
THE HUDSON VALLEY EARLY THIS MORNING AND SHOULD ARRIVE IN NEW
HAMPSHIRE IN THE NEXT TWO HOURS BEFORE SPREADING EASTWARD ACROSS
THE REST OF NEW HAMPSHIRE AND WESTERN MAINE THIS MORNING. THIS
AREA OF PRECIPITATION IS ASSOCIATED WITH A WARM FRONT-LIKE
FEATURE IN THAT BEHIND IT DEWPOINTS ARE SURGING INTO THE MID 60S
WHILE THE COOL MARITIME AIR MASS AHEAD OF IT IS COOLER AND WITH
LOWER DEWPOINTS. BUT YOU WILL BE HARD PRESSED TO FIND A
NOTICEABLE WIND SHIFT OR PRESSURE TROUGH WITH IT. SUCH IS LIFE IN
NORTHERN NEW ENGLAND.

AREA OF RAIN WILL MOVE INTO THE MIDCOAST REGION OF MAINE LATE IN
THE MORNING AND PERSIST INTO THE AFTERNOON. WHILE NEW HAMPSHIRE
WILL SEE THE RAIN ENDING EARLIER IN THE MORNING. BREAKS IN THE
CLOUDS SHOULD ALLOW FOR PRETTY GOOD WARMING INTO THE MID TO UPPER
70S OVER WESTERN NEW HAMPSHIRE. THE COMBINATION OF THIS WARMING...
THE INCREASING LOW LEVEL MOISTURE... AND COOLING TEMPERATURES
ALOFT ASSOCIATED WITH A SHORTWAVE TROUGH WILL PROVIDE SUBSTANTIAL
INSTABILITY THIS AFTERNOON... PERHAPS THE BEST SEEN YET THIS
SEASON. CAPE APPROACHES OR EXCEEDS 1000 BY LATE THIS AFTERNOON AND
EARLY EVENING OVER VERMONT AND NEW HAMPSHIRE. JUST AS INSTABILITY
IS INCREASING... A COLD FRONT WILL BEGIN MOVING ACROSS NORTHERN
NEW ENGLAND FROM WEST TO EAST. THIS WILL PROVIDE LOW LEVEL
CONVERGENCE TO ADD LIFT TO THE EQUATION... AIDING IN THE
DEVELOPMENT OF THUNDERSTORMS. BEST INSTABILITY AND LIFT DOES NOT
ARRIVE UNTIL LATE IN THE DAY... SO THUNDERSTORM POTENTIAL SEEMS TO
BE MORE IN THE 4PM-8PM TIME PERIOD... WITH REMNANT STORMS LIKELY
MAINTAINING THEMSELVES THROUGH ELEVATED INSTABILITY THROUGH
MIDNIGHT TONIGHT.

MESOSCALE MODELS INCLUDING THE NAM AND HRRR INDICATING POTENTIALLY
TWO SEPARATE AREAS OF MORE WIDESPREAD THUNDERSTORM ACTIVITY LATE
THIS AFTERNOON. THE FIRST IS OVER THE NORTHERN ADIRONDACKS AND THE
SECOND OVER THE CATSKILLS... BOTH AREAS FIRING AS THE FRONT MOVES
THROUGH TO PROVIDE LIFT AND MAY BE ENHANCED DUE TO TERRAIN-BASED
INSTABILITY. IF THIS SCENARIO UNFOLDS... THEN THE NORTHERN AREA OF
THUNDERSTORMS WOULD MOVE EAST ACROSS VERMONT AND THE NORTHERN HALF
OF NEW HAMPSHIRE AND INTO NORTHWEST MAINE IN THE EVENING. THE
SOUTHERN CLUSTER WOULD MOVE EAST MAINLY INTO MASSACHUSETTS. HAVE
ORIENTED AFTERNOON/EVENING THUNDERSTORM CHANCES AS BEING GREATEST
IN THE NORTH WHERE THE MORE NORTHERN CLUSTER OF STORMS WOULD MOVE
ACROSS BUT HAVE MAINTAINED AT LEAST A CHANCE OF THUNDERSTORMS OVER
ALL OF NEW HAMPSHIRE AND EXTENDING INTO FAR WESTERN/NORTHERN
MAINE IN THE EVENING.

ONE FINAL INGREDIENT TO ADD TO THE MIX TODAY IS INCREASING WIND
SHEAR. BY EVENING... AROUND THE TIME THE FRONT WILL BE MOVING INTO
NEW HAMPSHIRE... WINDS ALOFT APPROACH 50 KT AT 700 MB WHILE
SURFACE WINDS ARE BROADLY LIGHT OUT OF THE SOUTH. THIS WILL
PROVIDE ENOUGH SPEED SHEAR TO PROVIDE STORM ORGANIZATION AND
SUPERCELL TYPE STRUCTURES. THIS MAKES SEVERE THUNDERSTORMS MORE
LIKELY... WITH DAMAGING WINDS AND HAIL BEING THE PRIMARY THREATS.
HOWEVER... GIVEN LOW LEVEL WINDS OUT OF THE SOUTH... CANNOT RULE
OUT THE POSSIBILITY OF AN ISOLATED TORNADO PARTICULARLY IN AREAS
WHERE LOW LEVEL WINDS ARE CHANNELED BY TERRAIN AND PRODUCE GREATER
LOCALIZED DIRECTIONAL SHEAR. HAVE MENTIONED THE THREAT OF DAMAGING
WINDS AND LARGE HAIL IN THE PUBLIC FORECAST FOR LATE THIS
AFTERNOON. HAVE ALSO ORIENTED HOURLY PRECIPITATION CHANCES TO
BETTER REFLECT THE IDEA THAT EARLY MORNING SHOWERS WILL MOVE EAST
BEFORE THE CHANCE OF THUNDERSTORMS ARRIVES LATE.

&&

.SHORT TERM /TONIGHT AND WEDNESDAY/...
COLD FRONT WILL PUSH EAST ACROSS THE REGION TONIGHT WITH
THUNDERSTORM ACTIVITY LIKELY LINGERING INTO THE EVENING...
POSSIBLY TO AROUND MIDNIGHT IN NORTHERN MAINE. COOLER AND DRIER
AIR WILL BE MOVING IN BEHIND THE COLD FRONT. COULD SEE SOME FOG
NEAR THE COAST BEFORE THE FRONT MOVES THROUGH AND BEGINS TO
MIX/DRY THINGS OUT. TEMPERATURES FALL INTO THE UPPER 40S AND LOW
50S.

WILL BE A COOLER DAY ON WEDNESDAY FOR MOST OF THE REGION. BUT ON
THE COAST IT MAY ACTUALLY BE A FEW DEGREES WARMER... A TYPICAL
RESULT OF A PASSING COLD FRONT AND A SHIFT TO OFFSHORE WINDS. HIGH
TEMPERATURES RANGE FROM THE MID 50S IN THE NORTH TO THE MID 60S
NEAR THE COAST. DEWPOINTS WILL BE FALLING INTO THE 30S WHICH WILL
MAKE IT DIFFICULT FOR ANY SHOWERS TO DEVELOP IN SPITE OF SOME LIFT
MOVING THROUGH WITH THE PASSING OF THE UPPER LEVEL TROUGH.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
A LARGE UPPER LEVEL TROUGH WILL DOMINATE THE FLOW ACROSS NEW
ENGLAND THROUGH THE WEEKEND. SEVERAL DISTURBANCES WILL ROTATE
AROUND THE TROUGH, HOWEVER, COOL DRY WEATHER WILL RULE FOR MUCH OF
THE PERIOD. A MOISTURE-STARVED FRONT DROPPING SOUTHWARD FROM
CANADA COULD BRING A FEW SHOWERS TO THE REGION FRIDAY. BEHIND THE
FRONT...TEMPERATURES WILL BE MAINLY IN THE 60S SATURDAY BUT SHOULD
START TO WARM INTO THE 70S MOST AREAS FOR SUNDAY AND MONDAY AS THE
TROUGH AXIS SLIDES EAST OF THE REGION. MODELS NOW DELAY NEXT
SIGNIFICANT PRECIPITATION UNTIL TUESDAY, ALLOWING FOR A VERY
PLEASANT HOLIDAY WEEKEND.

NOTE: THE FREEZE/FROST PROGRAM STARTS IN NORTHERN ZONES
THURSDAY MAY 21. LOW TEMPERATURES THURSDAY AND SATURDAY MORNINGS
WILL DROP NEAR OR BELOW FREEZING ACROSS NORTHERN ZONES AND MAY
REQUIRE FREEZE WARNINGS AND/OR FROST ADVISORIES.

&&

.AVIATION /07Z TUESDAY THROUGH SATURDAY/...
SHORT TERM...EARLY MORNING IFR/LIFR CONDITIONS WILL BEGIN
IMPROVING THIS MORNING EVEN AS AN AREA OF RAIN MOVES ACROSS THE
AREA. COULD SEE MVFR CEILINGS LINGER THROUGH MUCH OF THE DAY BUT
THERE IS A BETTER CHANCE THAT CONDITIONS WILL BREAK OUT TO VFR FOR
AT LEAST A FEW HOURS. THERE IS A CHANCE OF THUNDERSTORMS ACROSS
MUCH OF NEW HAMPSHIRE LATE THIS AFTERNOON INTO EARLY THIS EVENING.
LOW CLOUDS MAY MAKE A RETURN VISIT TO COASTAL MAINE EARLY THIS
EVENING BUT THE PASSING OF A COLD FRONT DURING THE NIGHT WILL
LIKELY IMPROVE CONDITIONS TO VFR EVENTUALLY.

LONG TERM...MAINLY VFR CONDITIONS EXPECTED.

&&

.MARINE...
SHORT TERM...SOUTHERLY FLOW INCREASES TODAY THEN SHIFTS TO THE
WEST TONIGHT BEHIND A COLD FRONT. WEST WINDS COULD GUST TO AROUND
20 KT ON WEDNESDAY.

LONG TERM...WITH MAINLY OFFSHORE FLOW...WINDS AND SEAS EXPECTED
TO REMAIN BELOW SCA CRITERIA. STRONGEST WINDS AND HIGHEST SEAS
SHOULD BE WELL OFFSHORE.

&&

.FIRE WEATHER...
MOIST AIR AND WIDESPREAD WETTING RAIN TODAY WILL KEEP FIRE DANGER
CONDITIONS LOW. DRY AIR MOVES IN BEHIND A COLD FRONT TONIGHT...
LEADING TO MUCH DRIER CONDITIONS WEDNESDAY INTO THE WEEKEND.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.

&&

$$

NEAR TERM...KIMBLE
SHORT TERM...KIMBLE
LONG TERM...JENSENIUS




AREA FORECAST DISCUSSION

NWS WAKEFIELD VA

 200 AM EDT TUE MAY 19 2015

.SYNOPSIS...
HIGH PRESSURE REMAINS ANCHORED OFF THE SOUTHEAST COAST THROUGH
TUESDAY. A COLD FRONT CROSSES THE REGION TUESDAY NIGHT. HIGH
PRESSURE BUILDS INTO THE AREA FROM THE WEST WEDNESDAY THROUGH
THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
LATEST REGIONAL RADAR MOSAIC DEPICTS ISOLATED TO WIDELY SCATTERED
SHOWERS/THUNDERSTORMS ACROSS THE NW COUNTIES...WITH ANOTHER ISOLATED
THUNDERSTORM OVER HOPEWELL AS OF THIS WRITING. BETTER COVERAGE OF
SHOWERS AND THUNDERSTORMS FOUND JUST NORTH OF THE LOCAL AREA.
EARLIER THUNDERSTORMS HAVE LEFT BEHIND SEVERAL BOUNDARIES THIS
EVENING. WARM/HUMID AIRMASS REMAINS IN PLACE...WITH RAP MESOANALYSIS
DEPICTING 1000-1500 J/KG MLCAPE. BETTER FORCING ALOFT ALSO INDICATED
(ALBEIT LIMITED OVER THE LOCAL AREA) AS A SHORTWAVE VISIBLE ON WATER
VAPOR LIFTS ACROSS THE OH VALLEY. EXPECT THE BEST COVERAGE OF
SHOWERS/THUNDERSTORMS TO REMAIN NORTH OF THE LOCAL AREA
TONIGHT...BUT COMBINATION OF OUTFLOW BOUNDARIES AND
WARM/MOIST/RELATIVELY UNSTABLE AIRMASS WILL RESULT IN SLIGHT CHANCE-
CHANCE POPS THRU THE OVERNIGHT PERIOD. STORMS EXPECTED TO REMAIN SUB-
SEVERE DUE TO WEAK SHEAR PROFILES...BUT MEAN FLOW AOB 10 KT WILL
RESULT IN LOCALLY HEAVY RAINFALL.

BACKDOOR FRONT ALSO LOCATED OVER THE MD ERN SHORE THIS
EVENING...WITH ONSHORE FLOW OBSERVED AT OCEAN CITY WITH TEMPS
DROPPING INTO THE MID 60S. FOG OBSERVED DOV/GED/OXB...WITH
ADDITIONAL FOG EXPECTED THANKS TO ONSHORE FLOW. HAVE INCLUDED
AREAS OF FOG GENERALLY EAST OF HIGHWAY 13 IN MD. DO NOT ANTICIPATE
DENSE FOG ATTM. MILD TONIGHT WITH LOWS IN THE UPPER 60S TO AROUND
70 DEGREES. SKIES AVG PARTLY CLOUDY.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY/...
A COLD FRONT MOVING THROUGH THE MIDWEST THIS AFTN WILL REACH THE
SPINE OF THE APPALACHIANS AROUND 12Z TUE. THE COLD FRONT THEN
CROSSES THE LOCAL AREA TUESDAY AFTN/EVE...BEFORE PUSHING OFFSHORE
TUE NIGHT. BULK SHEAR REMAINS MARGINAL AT BEST AND DOWNSLOPE FLOW
ALOFT IS LESS THAN IDEAL FOR WIDESPREAD CONVECTIVE DEVELOPMENT.
HOWEVER...STRONG SFC HEATING PRE-FRONTAL SHOULD YIELD ANOTHER
ROUND OF SCATTERED SHWRS/TSTMS IN THE AFTN/EVE. WARM AND HUMID
AGAIN TUE. HIGHS FROM THE MID 80S TO AROUND 90 (EXCEPT COOLER AT
THE IMMEDIATE COAST). LOWS TUE NIGHT IN THE 60S.

COOL/DRY HIGH PRESSURE BEGINS TO BUILD TOWARD THE AREA FROM THE
WEST ON WEDNESDAY...YIELDING A DRIER/MORE COMFORTABLE DAY WITH
PLENTY OF SUNSHINE. HIGH TEMPS FROM THE MID 70S NORTH TO THE LOW
80S SOUTH. COMFORTABLE WED NIGHT WITH LOWS IN THE MID 50S TO LOW
60S. SHORTWAVE ENERGY DIVES SOUTH INTO THE CAROLINAS ON THURSDAY
WITH WEAK SFC LOW PRESSURE DEVELOPING ALONG A STALLED FRONTAL
BOUNDARY. MOISTURE ASSOCIATED WITH THIS SYSTEM WILL GET SHOVED
NORTHWARD INTO THE LOCAL AREA...ESPECIALLY IN THE AFTN/EVE. WILL
CONTINUE TO CARRY CHC POPS FOR MUCH OF THE AREA. HOWEVER...IT
APPEARS THE HIGHEST LIKELIHOOD OF PCPN WILL BE ACROSS SE PARTS OF
THE FA. PLEASANT TEMPS ON THU WITH HIGHS MOSTLY IN THE 70S.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
MEDIUM RANGE BEGINS WITH LATEST GFS/ECMWF INTO GOOD AGREEMENT WITH
WEAK UPPER TROUGH AXIS CROSSING THE REGION THU NIGHT...AND SFC LOW
PRESSURE SLIDING OFF THE COAST. WILL MAINTAIN LOW CHC POPS THU
NIGHT...AND SLIGHT CHC POPS THROUGH FRI MORNING IN THE FAR SE.
OTHERWISE. HIGH PRESSURE THEN GRADUALLY BUILDS ESE FROM THE UPPER
MIDWEST FRI-SAT...AND SLIDES OFF THE COAST ON SUN. THIS WILL RESULT
IN DRY CONDITIONS WITH COOLER TEMPERATURES FRI/SAT...PARTICULARLY AT
THE COAST ON SAT AS THE STRENGTH OF THE HIGH IS FAIRLY IMPRESSIVE...1030
MB+ AND ONSHORE FLOW INCREASES IN THE AFTN AS A PIECE OF THE HIGH
BECOMES CENTERED JUST OFFSHORE. SKIES WILL AVG MOSTLY SUNNY BOTH
DAYS ASIDE FROM SOME LINGERING CLOUDS FRI MORNING. HIGHS FRI WILL
BE FROM 75-80 F INLAND...TO 70-75 F NEAR THE COAST...TRENDING DOWN
TO THE MID 70S SAT INLAND TO ONLY THE UPPER 60S/LOWER 70S AT THE
COAST. LOWS WILL GENLY RANGE THROUGH THE 50S SAT AND SUN MORNING. FLOW
TURNS AROUND TO THE SSW SUN/MON AS SFC HIGH PUSHES WELL OFFSHORE
AND UPPER RIDGE AXIS MOVES BACK INTO THE REGION. HIGHS WARM BACK
INTO THE LWR 80S INLAND ON SUN...AND 85-90 F BY MON. CONDITIONS
BOTH DAYS WILL BE ABOUT 5 DEGREES COOLER AT THE COAST. WILL KEEP
FORECAST DRY THROUGH MIDDAY MON...THEN CARRY 20-30% POPS ACRS THE
NORTH BY MON AFTN.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
WILL MAINTAIN MAINLY VFR CONDITIONS AT ALL TAF SITES THRU THE 06Z
TAF PERIOD. ALTHO...EXPECT MVFR AND EVEN IFR CONDITIONS AT SBY
THRU EARLY THIS MORNG...DUE TO AREA OF SHOWERS AND POSSIBLY A TSTM
MOVNG THRU. OTHERWISE...WILL HAVE A VCSH AT OTHER TAF SITES DUE TO
CURRENT ACTIVITY ON RADAR...AND LINGERING INSTABILITY/BOUNDARIES
WITH SURFACE TROF CROSSING THE REGION.

CONTINUED CHCS FOR SHOWERS/TSTMS DURING TODAY...AS A COLD FRONT
APPROACHES AND MOVES ACRS THE AREA. FOR NOW...HAVE A VCSH STARTING
AT 16Z-18Z AT THE TAF SITES AND CONTINUING INTO EARLY THIS EVENG.

FRONT PUSHES OFF THE CST TNGT INTO WED MORNG...WITH NORTHERLY
WINDS BEHIND THE BOUNDARY USHERING DRIER AIR INTO THE REGION. VFR
CONDITIONS THEN EXPECTED THRU WED...AS HI PRES BLDS INTO THE AREA.
NEXT THREAT FOR SHOWERS/TSTMS WILL BE THU...AS A SHRTWV TROF
MOVES ACRS THE REGION.

&&

.MARINE...
WEAK SFC TROUGH OVER THE WATERS...WITH GENLY A LIGHT ONSHORE FLOW
LESS THAN 10 KT...THOUGH WIND DIRECTIONS ARE SOMEWHAT CHAOTIC DUE
TO SCATTERED TSTMS AND VERY WEAK PRESSURE GRADIENT. WINDS WIND
SHIFT TO BECOME A BIT MORE ORGANIZED FROM THE S/SE LATER THIS
EVENING...AND S/SW OVERNIGHT BUT SPEEDS AVG 10 KT OR LESS WITH
SEAS ONLY 2-3 FT AND WAVES IN THE BAY ONLY AROUND 1 FOOT (1-2 FT
MOUTH OF BAY). A COLD FRONT PUSHES ACROSS THE WATERS LATE TUE
(WITH PSBL SHRAS/TSTMS). WINDS BECOME N-NW POST- FRONTAL TUE
NIGHT. NOT A REAL STRONG COLD FRONT...BUT DOES APPEAR TO BE
SUFFICIENT COOL AIR SURGE TO LEAD TO LOW END SCA CONDITIONS FOR
THE BAY (AND PERHAPS THE RIVERS/SOUND). AT THIS TIME...KEEPING
CONDS BELOW SCA FOR THE OCEAN. IT WILL TEND TO BE FAIRLY SHORT IN
DURATION (AROUND 6 HRS..FROM AROUND 3-4 AM/WED THROUGH LATE
MORNING OR NOON/WED). SFC HI PRES BUILDS INTO THE RGN FM THE W WED
NIGHT...WITH A WEAK LOW PRESSURE SYSTEM PASSING BY TO THE SOUTH ON
THU. SOME UNCERTAINTY ON EXACT TRACK OF THIS SYSTEM...FOR NOW
MODELS KEEP WINDS FAIRLY LIGHT...10-15 KT AT MOST ALTHOUGH THIS
COULD CHANGE. HIGH PRESSURE THEN BUILDS OVER THE AREA LATER FRI-
SUN...FAIRLY COOL AIRMASS INITIALLY WILL LIKELY BRING SOME
INCREASE IN WINDS FRI NIGHT INTO SAT.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...JDM
NEAR TERM...JDM/SAM
SHORT TERM...JDM/MAS
LONG TERM...LKB
AVIATION...TMG
MARINE...LKB




AREA FORECAST DISCUSSION

NWS MARQUETTE MI

 506 AM EDT TUE MAY 19 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 506 AM EDT TUE MAY 19 2015

LATEST WV IMAGERY AND RAP ANALYSIS INDICATED A MID/UPPER LEVEL
TROUGH FROM NE CANADA EXTENDING INTO THE UPPER GREAT LAKES WITH THE
WEAKENING REMANTS OF THE MID-LVL LOW CIRCULATION CENTER SW OF JAMES
BAY. AT THE SFC...A TROUGH EXTENDED ACROSS THE UPPER GREAT LAKES
FROM LOW PRES NOW OVER QUEBEC. WRAPAROUND MOISTURE FROM THE LOW
CIRCULATION STILL SUSTAINING SNOW SHOWERS MIXED WITH RAIN SHOWERS
ACROSS PORTIONS OF NRN UPPER MI EARLY THIS MORNING AS NOTED ON THE
MQT RADAR.

TODAY...SFC HIGH PRES WILL BUILD TOWARD THE AREA DURING THE DAY AS
LOW-LEVEL FLOW BECOMES INCREASINGLY ANTICYCLONIC. THE ASSOCIATED
DRYING AS THE DEEPER MOISTURE DEPARTS TO THE EAST WILL ALLOW ANY
LINGERING SNOW SHOWERS TO GRADUALLY DIMINISH THIS MORNING FROM WEST
TO EAST AND END OVER MOST OF THE CWA BY 18Z. ONLY A DUSTING TO MAYBE
HALF AN INCH OF SNOW ACCUMULATION IS POSSIBLE ON GRASSY AREAS OF
NORTH CENTRAL HIGHER TERRAIN LOCATIONS BEFORE SNOW ENDS THIS
MORNING. CLOUDS WILL SLOWLY DISSIPATE FROM WEST TO EAST MAINLY
DURING THE MID TO LATE AFTERNOON WITH HIGHER PRESSURE AND ASSOC
DRIER AIR WORKING IN FM WEST. OTHERWISE...UNSEASONABLY COLD
CONDITIONS ARE EXPECTED UNDER GUSTY NW WINDS (20 TO 25 MPH
ESPECIALLY EAST HALF) AS HIGHS WILL RANGE FROM UPPER 30S/LOWER 40S
NORTH AND EAST TO THE MID AND UPPER 40S SOUTH AND WEST.

TONIGHT...HIGH PRESSURE BUILDS INTO THE AREA TONIGHT. THE DRY AIR
ASSOCIATED WITH THE HIGH WILL DIMINISH ANY LINGERING CLOUDS OVER THE
EASTERN CWA QUICKLY DURING THE EARLY EVENING HOURS. THE CLEARING
SKIES AND WEAKENING WINDS WILL LEAD TO A COLD NIGHT ACROSS THE AREA.
HAVE FOLLOWED THE LOWER END OF MODEL GUIDANCE (GIVEN PWAT VALUES AT
OR BELOW 0.25IN ACROSS MUCH OF THE INTERIOR)...WHICH INDICATES
VALUES IN THE 20S FOR MOST INTERIOR LOCATIONS...COLDEST INTERIOR
WEST ALONG THE WI BORDER WHERE LOWS COULD DIP INTO THE LOWER TO MID
20S. ALTHOUGH OUR FROST/FREEZE PROGRAM HASN/T STARTED YET...WOULD
EXPECT A WIDESPREAD FROST ACROSS UPPER MICHIGAN AND A HARD FREEZE
OVER THE INTERIOR WEST. PERSONS WITH SENSITIVE PLANTS SHOULD TAKE
THE NECESSARY PRECAUTIONS TO PROTECT AGAINST A HARD FROST AND/OR
FREEZE AND WILL INCLUDE A MENTION OF THIS IN THE HWO STATEMENT.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 238 AM EDT TUE MAY 19 2015

FROM WEDNESDAY THROUGH THE END OF THE WORK WEEK...A 500MB TROUGH
WILL REMAIN ACROSS THE GREAT LAKES REGION. THE LOW ITSELF WILL GET
AS CLOSE AS JAMES BAY THURSDAY AFTERNOON. AT THE SFC MUCH OF THIS
TIME PERIOD WILL BE MARKED BY A RIDGE OF HIGH PRESSURE EXTENDING
EITHER S CENTRAL CANADA OR THE NORTHERN TO CENTRAL PLAINS. LOOK FOR
THE RIDGE TO BE SUPPRESSED WEDNESDAY AFTERNOON INTO THURSDAY. A W-E
ORIENTED COLD FRONT SET UP JUST N OF LAKE SUPERIOR ACROSS ONTARIO
WILL SINK ACROSS LAKE SUPERIOR WEDNESDAY AFTERNOON...AND UPPER MI
WEDNESDAY NIGHT BEFORE PUSHING ACROSS WI AND LOWER MI DURING THE DAY
THURSDAY.

WEDNESDAY WILL BE DRY...AND EVEN WITH GOOD MIXING WINDS SHOULD STAY
FAIRLY LIGHT AS YOU NEED TO GO ABOVE 500MB TO GET ANYTHING ABOVE
15KTS. THE COLD FRONT SINKING THROUGH WILL BRING SOME MOISTURE TO
THE AREA...BUT IT/S NOT LOOKING LIKE MUCH MORE THAN CLOUD COVER.
MOST MODELS DO SHOW A BETTER CHANCE FOR AT LEAST SPRINKLES JUST S OF
MENOMINEE AND LOWER MI THURSDAY AFTERNOON...BUT NOTHING FOR UPPER
MI. THIS IS HANDLES WELL IN OUR PREVIOUS FCST...SO LIMITED CHANGES
WILL BE NEEDED. ANY REAL WARM UP WILL HAVE TO WAIT UNTIL THE
WEEKEND...AS COOL N WINDS OFF LAKE SUPERIOR AND 850MB TEMPS ON
THURSDAY HOVERING AROUND 2C. 850MB TEMPS MAY GET DOWN TO -3 OR -4C E
BY 12Z FRIDAY...LEADING TO ANOTHER CHILLY MORNING. OVERNIGHT LOWS IN
THE 30S WILL BE COMMON BOTH WEDNESDAY NIGHT AND THURSDAY NIGHT.

SATURDAY WILL BE A TRANSITION DAY AS THE CANADIAN HIGH EDGES TO THE
SE AND SLIGHTLY WARMER AIR MOVES IN. IT WILL END UP BEING THE
WARMEST DAY THIS WEEK WITH HIGHS NEAR NORMAL /60S TO AROUND 70F/.

THE 500MB RIDGE WILL STRENGTHEN OVER THE CWA SUNDAY AND MONDAY AS
THE SFC RIDGE LINGERS. THE GFS IS A BIT MORE AGGRESSIVE WITH THE MAIN
500MB TROUGH DIGGING BACK INTO THE UPPER GREAT LAKES ON
MONDAY...LEADING TO A STRONGER SYSTEM OVERALL. THE APEX OF THE RIDGE
WILL BE NEARBY AROUND 12Z MONDAY...WITH SW FLOW RETURNING AHEAD OF A
SFC LOW NEARING FROM THE SW. THE BEST CHANCE OF PRECIP IN THIS
LONGER TERM PERIOD WILL LIKELY HOLD OFF UNTIL THE DAYTIME HOURS
MONDAY. THERE IS STILL SOME UNCERTAINTY AS TO WHETHER THE BEST
CHANCE WILL BE OVER THE N OR S...DEPENDING ON THE TRACK/STRENGTH OF
THE SFC LOW AND NEARING SHORTWAVE ENERGY.
&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 122 AM EDT TUE MAY 19 2015

WRAPAROUND MOISTURE IN LIGHT SNOW SHOWERS WILL CONTINUE TO AFFECT
ALL SITES DURING THE EARLY MORNING HOURS WITH IFR TO MVFR CONDITIONS
EXPECTED. SITES WILL BEGIN TO IMPROVE SLIGHTLY TOWARD 12Z BUT WILL
STILL REMAIN MVFR. VFR CONDITIONS WITH MUCH DRIER AIR AND MIXING MOVE
INTO CMX AND IWD THIS AFTERNOON AND WILL TAKE UNTIL THIS EVENING TO
GET VFR AT SAW WHICH WILL STAY MVFR THROUGH THEN.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 506 AM EDT TUE MAY 19 2015

LOW PRES CENTERED OVER QUEBEC WILL CONTINUE TO LIFT NE TODAY AS HIGH
PRES GRADUALLY BUILDS IN FM THE WEST. NNW WINDS TO 20 TO 30 KNOTS
(HIGHEST EAST HALF) THIS MORNING WILL DIMINISH W TO E THIS
AFTERNOON/TONIGHT AS THE HIGH BUILDS IN FM THE WEST DECREASING THE
PRES GRADIENT. WED THRROUGH SAT...WINDS WILL BE UNDER 20KT AS SFC
HIGH PRES REMAINS IN CONTROL THROUGH MUCH OF THE PERIOD.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...VOSS
LONG TERM...KF
AVIATION...07
MARINE...VOSS



AREA FORECAST DISCUSSION

NWS MARQUETTE MI

 239 AM EDT TUE MAY 19 2015

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 359 PM EDT MON MAY 18 2015

WV IMAGERY AND RAP ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH FROM
NW ONTARIO INTO THE WRN GREAT LAKES WITH THE LOW CIRCULATION CENTER
NEAR CYQT. AT THE SFC...A TROUGH EXTENDED THROUGH NRN LAKE SUPERIOR
FROM LOW PRES E OF LAKE SUPERIOR. WITH THE WRAP-AROUND MOISTURE/PCPN
MOVING EDGING TOWARD THE AREA...RADARS INDICATED DIURNALLY ENHANCED
SCT/NMRS -SHSN/SHRA FROM NE MN INTO NW WI. SOME LIGHT RAIN OR
DRIZZLE HAD ALSO DEVELOPED INTO UPSLOPE FLOW LOCATIONS OF NW UPPER
MI.

TONIGHT...THE COMBINATION OF DEEP MOISTURE SLIDING INTO THE AREA
BEHIND THE MID LEVEL LOW AND CAA DROPPING 850 MB TEMPS INTO THE -8C
TO -11C RANGE WILL SUPPORT SCT/NMRS -SHRA/-SHSN INTO MAINLY THE WEST
HALF OF UPPER MI. THE MOST FAVORABLE UPSLOPE FLOW AND LOW LEVEL CONV
WILL SHIFT TO LOCATIONS OVER THE W FAVORED BY NRLY FLOW AND INTO N
CNTRL UPPER MI LATE. LOW LEVEL THICKNESS AND WET-BULB ZERO HEIGHTS
SUGGEST ANY PCPN WILL CHANGE OVER TO MAINLY SNOW FROM WEST TO EAST
THIS EVENING. ALTHOUGH QPF AMOUNTS TO AROUND A TENTH OF AN INCH ARE
EXPECTED...WITH THE RELATIVELY WARM GROUND...ANY SNOWFALL AMOUNTS
SHOULD REMAIN AROUND A HALF INCH OR LESS...MAINLY ON GRASSY SURFACES.

TUE...AS HIGH PRES BUILDS TOWARD THE AREA WITH INCREASINGLY ACYC
LOW LEVEL FLOW...AND THE DEEPER MOISTURE DEPARTS TO THE EAST...THE
LINGERING SNOW SHOWERS SHOULD GRADUALLY DIMINISH AND END OVER MOST OF
THE CWA BY 18Z. THERE MAY BE SOME LIGHT PCPN LINGERING OVER THE EAST
DURING THE AFTERNOON. CLOUDS WILL ALSO ONLY SLOWLY DISSIPATE FROM
WEST TO EAST DURING THE MID TO LATE AFTERNOON.
OTHERWISE...UNSEASONABLY COLD CONDITIONS ARE EXPECTED WITH HIGHS
ONLY FROM AROUND 40 NORTH TO THE MID AND UPPER 40S SOUTH AND WEST.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 238 AM EDT TUE MAY 19 2015

FROM WEDNESDAY THROUGH THE END OF THE WORK WEEK...A 500MB TROUGH
WILL REMAIN ACROSS THE GREAT LAKES REGION. THE LOW ITSELF WILL GET
AS CLOSE AS JAMES BAY THURSDAY AFTERNOON. AT THE SFC MUCH OF THIS
TIME PERIOD WILL BE MARKED BY A RIDGE OF HIGH PRESSURE EXTENDING
EITHER S CENTRAL CANADA OR THE NORTHERN TO CENTRAL PLAINS. LOOK FOR
THE RIDGE TO BE SUPPRESSED WEDNESDAY AFTERNOON INTO THURSDAY. A W-E
ORIENTED COLD FRONT SET UP JUST N OF LAKE SUPERIOR ACROSS ONTARIO
WILL SINK ACROSS LAKE SUPERIOR WEDNESDAY AFTERNOON...AND UPPER MI
WEDNESDAY NIGHT BEFORE PUSHING ACROSS WI AND LOWER MI DURING THE DAY
THURSDAY.

WEDNESDAY WILL BE DRY...AND EVEN WITH GOOD MIXING WINDS SHOULD STAY
FAIRLY LIGHT AS YOU NEED TO GO ABOVE 500MB TO GET ANYTHING ABOVE
15KTS. THE COLD FRONT SINKING THROUGH WILL BRING SOME MOISTURE TO
THE AREA...BUT IT/S NOT LOOKING LIKE MUCH MORE THAN CLOUD COVER.
MOST MODELS DO SHOW A BETTER CHANCE FOR AT LEAST SPRINKLES JUST S OF
MENOMINEE AND LOWER MI THURSDAY AFTERNOON...BUT NOTHING FOR UPPER
MI. THIS IS HANDLES WELL IN OUR PREVIOUS FCST...SO LIMITED CHANGES
WILL BE NEEDED. ANY REAL WARM UP WILL HAVE TO WAIT UNTIL THE
WEEKEND...AS COOL N WINDS OFF LAKE SUPERIOR AND 850MB TEMPS ON
THURSDAY HOVERING AROUND 2C. 850MB TEMPS MAY GET DOWN TO -3 OR -4C E
BY 12Z FRIDAY...LEADING TO ANOTHER CHILLY MORNING. OVERNIGHT LOWS IN
THE 30S WILL BE COMMON BOTH WEDNESDAY NIGHT AND THURSDAY NIGHT.

SATURDAY WILL BE A TRANSITION DAY AS THE CANADIAN HIGH EDGES TO THE
SE AND SLIGHTLY WARMER AIR MOVES IN. IT WILL END UP BEING THE
WARMEST DAY THIS WEEK WITH HIGHS NEAR NORMAL /60S TO AROUND 70F/.

THE 500MB RIDGE WILL STRENGTHEN OVER THE CWA SUNDAY AND MONDAY AS
THE SFC RIDGE LINGERS. THE GFS IS A BIT MORE AGGRESSIVE WITH THE MAIN
500MB TROUGH DIGGING BACK INTO THE UPPER GREAT LAKES ON
MONDAY...LEADING TO A STRONGER SYSTEM OVERALL. THE APEX OF THE RIDGE
WILL BE NEARBY AROUND 12Z MONDAY...WITH SW FLOW RETURNING AHEAD OF A
SFC LOW NEARING FROM THE SW. THE BEST CHANCE OF PRECIP IN THIS
LONGER TERM PERIOD WILL LIKELY HOLD OFF UNTIL THE DAYTIME HOURS
MONDAY. THERE IS STILL SOME UNCERTAINTY AS TO WHETHER THE BEST
CHANCE WILL BE OVER THE N OR S...DEPENDING ON THE TRACK/STRENGTH OF
THE SFC LOW AND NEARING SHORTWAVE ENERGY.
&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 122 AM EDT TUE MAY 19 2015

WRAPAROUND MOISTURE IN LIGHT SNOW SHOWERS WILL CONTINUE TO AFFECT
ALL SITES DURING THE EARLY MORNING HOURS WITH IFR TO MVFR CONDITIONS
EXPECTED. SITES WILL BEGIN TO IMPROVE SLIGHTLY TOWARD 12Z BUT WILL
STILL REMAIN MVFR. VFR CONDITIONS WITH MUCH DRIER AIR AND MIXING MOVE
INTO CMX AND IWD THIS AFTERNOON AND WILL TAKE UNTIL THIS EVENING TO
GET VFR AT SAW WHICH WILL STAY MVFR THROUGH THEN.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 359 PM EDT MON MAY 18 2015

LOW PRES EAST OF LAKE SUPERIOR WILL CONTINUE TO MOVE TO THE EAST
TONIGHT. A TIGHTENING PRES GRADIENT AHEAD OF HIGH PRES BUILDING
TOWARD THE AREA FROM THE NRN PLAINS WILL BOOST NNW WINDS TO 20 TO 30
KNOTS WITH THE POTENTIAL FOR A FEW GALE FORCE GUSTS OVER THE E HALF
LATE TONIGHT AND TUE MORNING. WINDS WILL DIMINISH W TO E TUE
AFTERNOON/NIGHT THE HIGH BUILDS IN FM THE WEST. WED THRROUGH
SAT...WINDS WILL BE UNDER 20KT.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...JLB
LONG TERM...KF
AVIATION...07
MARINE...JLB




AREA FORECAST DISCUSSION

NWS MARQUETTE MI

 131 AM EDT TUE MAY 19 2015

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 359 PM EDT MON MAY 18 2015

WV IMAGERY AND RAP ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH FROM
NW ONTARIO INTO THE WRN GREAT LAKES WITH THE LOW CIRCULATION CENTER
NEAR CYQT. AT THE SFC...A TROUGH EXTENDED THROUGH NRN LAKE SUPERIOR
FROM LOW PRES E OF LAKE SUPERIOR. WITH THE WRAP-AROUND MOISTURE/PCPN
MOVING EDGING TOWARD THE AREA...RADARS INDICATED DIURNALLY ENHANCED
SCT/NMRS -SHSN/SHRA FROM NE MN INTO NW WI. SOME LIGHT RAIN OR
DRIZZLE HAD ALSO DEVELOPED INTO UPSLOPE FLOW LOCATIONS OF NW UPPER
MI.

TONIGHT...THE COMBINATION OF DEEP MOISTURE SLIDING INTO THE AREA
BEHIND THE MID LEVEL LOW AND CAA DROPPING 850 MB TEMPS INTO THE -8C
TO -11C RANGE WILL SUPPORT SCT/NMRS -SHRA/-SHSN INTO MAINLY THE WEST
HALF OF UPPER MI. THE MOST FAVORABLE UPSLOPE FLOW AND LOW LEVEL CONV
WILL SHIFT TO LOCATIONS OVER THE W FAVORED BY NRLY FLOW AND INTO N
CNTRL UPPER MI LATE. LOW LEVEL THICKNESS AND WET-BULB ZERO HEIGHTS
SUGGEST ANY PCPN WILL CHANGE OVER TO MAINLY SNOW FROM WEST TO EAST
THIS EVENING. ALTHOUGH QPF AMOUNTS TO AROUND A TENTH OF AN INCH ARE
EXPECTED...WITH THE RELATIVELY WARM GROUND...ANY SNOWFALL AMOUNTS
SHOULD REMAIN AROUND A HALF INCH OR LESS...MAINLY ON GRASSY SURFACES.

TUE...AS HIGH PRES BUILDS TOWARD THE AREA WITH INCREASINGLY ACYC
LOW LEVEL FLOW...AND THE DEEPER MOISTURE DEPARTS TO THE EAST...THE
LINGERING SNOW SHOWERS SHOULD GRADUALLY DIMINISH AND END OVER MOST OF
THE CWA BY 18Z. THERE MAY BE SOME LIGHT PCPN LINGERING OVER THE EAST
DURING THE AFTERNOON. CLOUDS WILL ALSO ONLY SLOWLY DISSIPATE FROM
WEST TO EAST DURING THE MID TO LATE AFTERNOON.
OTHERWISE...UNSEASONABLY COLD CONDITIONS ARE EXPECTED WITH HIGHS
ONLY FROM AROUND 40 NORTH TO THE MID AND UPPER 40S SOUTH AND WEST.

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 320 PM EDT MON MAY 18 2015

A GENERALLY QUIET LONG TERM PERIOD IS IN STORE FOR THE UPPER GREAT
LAKES REGION. THIS IS DUE TO THE AREA LARGELY BEING BETWEEN AN
UPPER TROUGH OVER EASTERN CANADA AND ANOTHER OVER THE SOUTHWESTERN
CONUS. WHILE THE UPPER GREAT LAKES REGION WILL BE BRUSHED BY A FEW
WAVES ASSOCIATED WITH THESE FEATURES...THE OVERALL FLOW WILL BE OUT
OF THE NORTHWEST OR WEST-NORTHWEST WITH LIMITED MOISTURE.

HIGH PRESSURE BUILDS INTO THE AREA ON TUESDAY NIGHT AND REMAINS
INTO WEDNESDAY. THE DRY AIR ASSOCIATED WITH THE HIGH WILL DIMINISH
ANY LINGERING CLOUDS OVER THE EASTERN CWA QUICKLY DURING THE EARLY
EVENING HOURS. THE CLEARING SKIES AND WEAKENING WINDS WILL LEAD TO
A COLD NIGHT ACROSS THE AREA ON TUESDAY NIGHT. HAVE FOLLOWED THE
LOWER END OF GUIDANCE (WITH PWAT VALUES ONLY AROUND 0.25IN)...WHICH
GIVES VALUES IN THE 20S FOR MOST INTERIOR LOCATIONS. ALTHOUGH OUR
FROST/FREEZE PROGRAM HASN/T STARTED...WOULD EXPECT A WIDESPREAD
FROST (AND A HARD FREEZE FOR THE INTERIOR WEST) ACROSS UPPER
MICHIGAN AND PERSONS WITH SENSITIVE PLANTS WOULD BE WISE TO PREPARE
FOR A SOLID FROST.

A WEAK COLD FRONT DROPS SOUTH FROM ONTARIO WEDNESDAY NIGHT AND WITH
THE LACK OF MOISTURE ONLY SHOWED A PERIOD OF PARTLY CLOUDY SKIES
AS IT MOVES THROUGH. BEHIND THE FRONT...NORTHERLY FLOW OFF LAKE
SUPERIOR WILL KEEP TEMPERATURES COOLER NEAR LAKE SUPERIOR ON
THURSDAY (50S) WHILE AREAS INLAND RISE TO OR JUST ABOVE 60.
FRIDAY/SATURDAY CONTINUE TO LOOK DRY (WITH TEMPERATURES WARMING
TOWARDS NORMAL) AS ANOTHER CANADIAN HIGH PRESSURE MOVES ACROSS THE
AREA.

THE HIGH WILL DEPART SATURDAY NIGHT...AS ENERGY FROM THE
SOUTHWESTERN CONUS TROUGH EJECTS NORTHEAST TOWARDS THE AREA. A
SURFACE LOW DEVELOPING IN THE PLAINS WITH THIS FEATURE WILL MOVE
INTO IOWA BY SUNDAY NIGHT BEFORE SLOWLY SHIFTING EAST THROUGH
SOUTHERN WISCONSIN BY MONDAY NIGHT. AT THIS POINT...EXPECT THE CWA
TO BE ON THE NORTHERN EDGE OF MUCH OF THE FORCING (WARM FRONT
STALLS OVER SOUTHERN WISCONSIN) AND BEST CHANCES FOR RAIN WILL BE
OVER THE SOUTHERN HALF OF THE CWA AS WEAK SHORTWAVES LIFT NORTHEAST
ACROSS THE AREA IN THE SOUTHWESTERLY FLOW.
&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 122 AM EDT TUE MAY 19 2015

WRAPAROUND MOISTURE IN LIGHT SNOW SHOWERS WILL CONTINUE TO AFFECT
ALL SITES DURING THE EARLY MORNING HOURS WITH IFR TO MVFR CONDITIONS
EXPECTED. SITES WILL BEGIN TO IMPROVE SLIGHTLY TOWARD 12Z BUT WILL
STILL REMAIN MVFR. VFR CONDITIONS WITH MUCH DRIER AIR AND MIXING MOVE
INTO CMX AND IWD THIS AFTERNOON AND WILL TAKE UNTIL THIS EVENING TO
GET VFR AT SAW WHICH WILL STAY MVFR THROUGH THEN.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 359 PM EDT MON MAY 18 2015

LOW PRES EAST OF LAKE SUPERIOR WILL CONTINUE TO MOVE TO THE EAST
TONIGHT. A TIGHTENING PRES GRADIENT AHEAD OF HIGH PRES BUILDING
TOWARD THE AREA FROM THE NRN PLAINS WILL BOOST NNW WINDS TO 20 TO 30
KNOTS WITH THE POTENTIAL FOR A FEW GALE FORCE GUSTS OVER THE E HALF
LATE TONIGHT AND TUE MORNING. WINDS WILL DIMINISH W TO E TUE
AFTERNOON/NIGHT THE HIGH BUILDS IN FM THE WEST. WED THRROUGH
SAT...WINDS WILL BE UNDER 20KT.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...JLB
LONG TERM...SRF
AVIATION...07
MARINE...JLB



AREA FORECAST DISCUSSION

NWS DULUTH MN

 246 AM CDT TUE MAY 19 2015

.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 245 AM CDT TUE MAY 19 2015

AN UPPER TROUGH WILL REMAIN OVER THE NORTHLAND TODAY...BUT DRIER
AIR AND WEAK HIGH PRESSURE AT THE SURFACE SHOULD SCOUR OUT THE
CLOUDS THAT COVERED MOST AREAS AS OF 0730Z AND KEEP MOST AREAS DRY
TODAY. SOME LIGHT SNOW SHOWERS CONTINUED EARLY THIS MORNING UNDER
THIS DECK OF STRATOCU AND THAT WILL CONTINUE UNTIL IT CLEARS. MORE
PERSISTENT SNOW SHOWERS ARE POSSIBLE OVER THE SNOWBELT REGION OF
ASHLAND/IRON COUNTIES. A SPOTTER IN GILE REPORTED SOME LIGHT SNOW
ACCUMULATION SHORTLY AFTER 05Z AND WEBCAMS AROUND IRONWOOD ALSO
SHOW SOME LIGHT ACCUMULATION. SHIP AND BUOY OBS INDICATE THE LAKE
IS AROUND 2 TO 4C AND WITH 850MB TEMPS AROUND -10C THIS
MORNING...FAVORABLE CONDITIONS FOR SNOW SHOWERS WILL CONTINUE THIS
MORNING. THE LAKE EFFECT WILL DIMINISH BY LATE MORNING AS TEMPS
WARM AND DRIER AIR CONTINUE TO MOVES IN. WE FOLLOWED THE RAP/NAM
ON CLEARING TODAY AND WENT WITH HIGHS IN THE FIFTIES FOR MOST AREAS.

TONIGHT WILL BE MOSTLY CLEAR...WITH SOME HIGH CLOUDS MOVING IN.
THE CLOUDS SHOULD BE THIN ENOUGH AND WINDS LIGHT ENOUGH TO ALLOW
FOR COLD TEMPERATURES. MOST AREAS WILL DROP BELOW FREEZING...WITH
SOME LOCALIZED AREAS INTO THE LOWER TWENTIES.

WE EXPECT PARTLY TO MOSTLY SUNNY SKIES WEDNESDAY WITH TEMPERATURES
WARMING INTO THE LOWER TO MIDDLE SIXTIES. A WEAK COLD FRONT WILL
JUST BE NEARING THE INTERNATIONAL BORDER BY EARLY WEDNESDAY
EVENING.

.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 245 AM CDT TUE MAY 19 2015

QUIET PERIOD THROUGH THE END OF THE WEEK ACROSS THE FORECAST AREA.
AN AREA OF HIGH PRESSURE WILL DOMINATE THE WEATHER ACROSS THE REGION
THROUGH SATURDAY WITH MAINLY SUNNY SKIES AND SLOWLY WARMING
TEMPERATURES.  MODELS SHOW A VERY WEAK FRONT WILL MOVE THROUGH THE
FORECAST REGION EARLY THURSDAY BUT ONLY CLOUDS WILL BE SEEN WITH
THIS SYSTEM.  THE NORTHWEST FLOW WILL SWITCH AROUND TO A S-SW FLOW
BY FRIDAY WHICH WILL ALLOW MOISTURE TO MOVE INTO THE REGION.  THE
MODELS INDICATE A LOW PRESSURE AREA TO MOVE INTO THE CENTRAL PLAINS
BY THE SATURDAY NIGHT/SUNDAY TIMEFRAME.  THIS WILL BRING A CHANCE
FOR SHOWERS TO THE REGION FOR SUNDAY AND MONDAY.  MODELS DO SHOW
SOME INCREASE INSTABILITY...SO WILL HAVE ISOLATED TSTMS IN THE
GRIDS.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 106 AM CDT TUE MAY 19 2015

AN AREA OF LOW PRESSURE JUST NORTH OF LAKE SUPERIOR WILL CONTINUE
MOVING NORTHEASTWARDS INTO QUEBEC PROVINCE. BEHIND IT HIGH
PRESSURE WILL BUILD INTO THE NORTHLAND THROUGH TUESDAY. CIGS WILL
VARY BETWEEN VFR/MVFR AT ALL SITES UNTIL AT LEAST 09Z. LAST
SEVERAL RAP SOUNDINGS AND LATEST NAM SHOW ALL SITES EXCEPT FOR
KHYR REACH VFR CIGS BETWEEN 09Z AND 13Z. KHYR SHOULD REACH VFR CIGS
AROUND 16Z. GUSTY WINDS WILL DEVELOP AT KDLH AND KHIB AROUND
13Z.


&&

.PRELIMINARY POINT TEMPS/POPS...
DLH  53  34  63  39 /   0   0   0   0
INL  53  26  66  36 /   0   0   0   0
BRD  55  30  65  42 /   0   0   0   0
HYR  53  27  64  38 /  10   0   0   0
ASX  53  32  62  38 /  20   0   0   0

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 7 AM CDT THIS MORNING FOR LSZ121-140-
     146>148.

&&

$$

SHORT TERM...MELDE
LONG TERM...STEWART
AVIATION...STEWART/WL






AREA FORECAST DISCUSSION...UPDATED

NWS DULUTH MN

 106 AM CDT TUE MAY 19 2015

.SHORT TERM...(THIS EVENING THROUGH TUESDAY AFTERNOON)
ISSUED AT 251 PM CDT MON MAY 18 2015

MAIN CONCERNS IN THE SHORT TERM ARE CENTERED AROUND THE LINGERING
RAIN AND SNOW SHOWERS ACROSS THE REGION THIS AFTERNOON AND EVENING
WITH AN INCOMING COLD AIR MASS FROM THE NORTH PRODUCING
TEMPERATURES 15 TO 20 DEGREES BELOW NORMAL TODAY...TONIGHT AND
TOMORROW.

STACKED LOW PRESSURE SYSTEM CURRENTLY LIFTING NEWD FROM THE TIP
OF THE ARROWHEAD INTO ONTARIO AND THE NRN GREAT LAKES THIS
AFTERNOON WITH A COLD CANADIAN AIR MASS FILLING IN BEHIND THE
DEPARTING SYSTEM ACROSS MUCH OF THE UPPER MIDWEST. THIS STRONG
AREA OF LOW PRESSURE WHICH BROUGHT MUCH NEEDED RAIN TO THE REGION
THIS PAST WEEKEND IS CONTINUING TO PRODUCE LIGHT RAIN SHOWERS OVER
THE AREA TODAY WITH THE COLD AIR MIXING IN ALLOWING FOR A FEW SNOW
SHOWERS AS WELL. THE COLD AND WET CONDITIONS ARE ALSO COMBINING
WITH GUSTY N/NW WINDS TODAY AS HIGH PRESSURE TO THE WEST AND THE
DEEP SYSTEM TO THE EAST INDUCE A TIGHT PRESSURE GRADIENT OVER NRN
MN. HAVE HAD REPORTS OF SUSTAINED WINDS 15 TO 20 MPH...AND GUSTS
NEAR OR EXCEEDING 30 MPH. IN CASE YOU FORGOT WHAT FALL FEELS LIKE.

PRECIPITATION TRENDS TONIGHT WILL BE DRYING AS THE SYSTEM
CONTINUES TO MOVE TO THE EAST AND HIGH PRESSURE AND DRIER AIR MOVE
IN OVER THE UPPER MIDWEST. THE GRADIENT WILL ALSO RELAX AS THE
HIGH MOVES IN...WHICH WILL ALLOW THE WINDS TO DIMINISH THROUGH THE
OVERNIGHT HOURS...BUT REMAIN LIGHT FROM THE N/NW.

THE COLD CONDITIONS WILL PERSIST TONIGHT WITH LOWS IN THE UPPER 20S
AND 30S OVER MUCH OF THE AREA. A FEW ISOLATED COLDER LOCATIONS
INTO THE LOWER TO MID 20S ARE NOT OUT OF THE QUESTION...ESPECIALLY
IF CLOUDS MIX OUT OVER N-CENTRAL MN BEFORE SUNRISE TUE MORNING.
EXPECTING WEAK LAKE INDUCED CLOUDS AND LIGHT SNOW/DRIZZLE ALONG
THE SOUTH SHORE TONIGHT AND EARLY TUE MORNING...BUT WITH ONLY
LIGHT AMTS ANTICIPATED. MOST OF THE DAY TUESDAY WILL BE SUNNY
ACROSS THE NORTHLAND...BUT WITH THE INFLUENCE FROM THE COLD AIR
MASS STILL IN PLACE ONLY ALLOWING TEMPERATURES TO REACH INTO THE
LOWER TO MID 50S.

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 251 PM CDT MON MAY 18 2015

IN SUMMARY...THE NORTHLAND CAN ANTICIPATE CLEAR SKIES FOR MOST OF
THE MIDDLE AND LATTER HALF OF THE WEEK WITH TEMPERATURES SLIGHTLY
ON THE COOLER SIDE OF NORMAL. THERE IS AN OPPORTUNITY FOR LIGHT
RAIN OVER THE SOUTHERN FORECAST AREA OVER THE WEEKEND.

SURFACE HIGH PRESSURE OVER THE NORTHERN PLAINS AND UPPER MIDWEST
WILL HELP KEEP THE NORTHLAND DRY AND SUNNY FOR THE MIDDLE AND
LATTER HALF OF THE WEEK. COOL NW FLOW ALOFT WILL KEEP TEMPERATURES
SLIGHTLY ON THE COOLER SIDE FOR TUESDAY NIGHT THROUGH THURSDAY
NIGHT. THE COLDEST NIGHT WILL BE TUESDAY NIGHT WITH TEMPERATURES
LIKELY FALLING INTO THE UPPER 20S AND LOW 30S EARLY WEDNESDAY.
LEANED ON THE COOLER NAM/GFS MOS GUIDANCE FOR TUESDAY NIGHT LOWS
SINCE THE CLEAR SKIES AND LIGHT WINDS WILL PROMOTE RADIATIONAL
COOLING. A WEAK COLD FRONT WILL MOVE THROUGH THE NORTHLAND LATE
WEDNESDAY AND EARLY THURSDAY...BUT AT THIS TIME...IT APPEARS THERE
WILL BE FEW CLOUDS AND NO PCPN WITH THE PASSAGE OF THIS FRONT.

THE PATTERN WILL BEGIN TO CHANGE LATE THIS WEEK. THE NW FLOW WILL
SUBSIDE FRIDAY. LIGHT SW TO W WINDS ARE LIKELY. THE GFS AND ECMWF
INCREASE 850 HPA TEMPERATURES FOR FRIDAY TO A COUPLE DEGREES MORE
THAN THURSDAY. THINK THE SUNNY SKIES AND GENERALLY WARMER AIR MASS
SHOULD FAVOR SLIGHTLY WARMER TEMPERATURES COMPARED TO
THURSDAY...SO INCREASED THE FRIDAY FORECAST A BIT. THE GFS
EXTENDED MOS CAME IN WITH A HIGH OF 68 FOR FRIDAY. AVOIDED
INCREASING THE HIGH TEMPERATURE FOR THE TWIN PORTS AREA THAT MUCH
BECAUSE THE LIGHT WIND FLOW REGIME COULD RESULT IN A SUBTLE LAKE
BREEZE.

THE GFS/GEM/ECMWF ARE INDICATING A LOW WILL MOVE INTO THE PLAINS
OVER THE WEEKEND...AND THE ASSOCIATED WARM FRONT WILL BEGIN TO LIFT
INTO THE UPPER MIDWEST. THE GFS BRINGS THE WARM FRONT...ESPECIALLY
THE ELEVATED 850 HPA WARM FRONT...FASTER AND FARTHER NORTH THAN THE
ECMWF. MAINTAINED LOW PCPN CHANCES FOR SHOWERS AND STORMS OVER THE
SOUTHERN FORECAST AREA SATURDAY THROUGH SUNDAY. EASTERLY FLOW MAY
DEVELOP SUNDAY...AND IF SO...THE COOL FLOW FROM THE LAKE COULD
SUPPRESS ANY CHANCE OF THUNDER TO WELL SOUTH OF HIGHWAY 2.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 106 AM CDT TUE MAY 19 2015

AN AREA OF LOW PRESSURE JUST NORTH OF LAKE SUPERIOR WILL CONTINUE
MOVING NORTHEASTWARDS INTO QUEBEC PROVINCE. BEHIND IT HIGH
PRESSURE WILL BUILD INTO THE NORTHLAND THROUGH TUESDAY. CIGS WILL
VARY BETWEEN VFR/MVFR AT ALL SITES UNTIL AT LEAST 09Z. LAST
SEVERAL RAP SOUNDINGS AND LATEST NAM SHOW ALL SITES EXCEPT FOR
KHYR REACH VFR CIGS BETWEEN 09Z AND 13Z. KHYR SHOULD REACH VFR CIGS
AROUND 16Z. GUSTY WINDS WILL DEVELOP AT KDLH AND KHIB AROUND
13Z.

&&

.PRELIMINARY POINT TEMPS/POPS...
DLH  34  63  39  63 /   0   0   0   0
INL  29  66  36  64 /   0   0   0   0
BRD  34  65  42  68 /   0   0   0   0
HYR  29  64  38  66 /   0   0   0   0
ASX  32  62  38  62 /   0   0   0   0

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 7 AM CDT THIS MORNING FOR LSZ121-140-
     146>148.

&&

$$

SHORT TERM...BJT
LONG TERM...GROCHOCINSKI
AVIATION...STEWART/WL






AREA FORECAST DISCUSSION

NWS LAS VEGAS NV

 915 PM PDT MON MAY 18 2015

.SYNOPSIS...AN AREA OF LOW PRESSURE LIFTING AWAY TO THE NORTHERN
INTERMOUNTAIN REGION WILL LEAVE LINGERING MOISTURE FOR SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS ACROSS THE SOUTHERN GREAT BASIN
TUESDAY. MOST AREAS WILL SEE DRY CONDITIONS ON WEDNESDAY AND
WEDNESDAY NIGHT. A NEW STORM SYSTEM WILL APPROACH THE AREA ON
THURSDAY THEN MOVE ACROSS ON FRIDAY BRINGING ADDITIONAL CHANCES FOR
SHOWERS AND THUNDERSTORMS. A SLOW DRYING AND WARMING TREND IS
EXPECTED FOR THE MEMORIAL DAY WEEKEND.
&&

.UPDATE...ONLY A FEW LINGERING LIGHT SHOWERS WERE INDICATED BY RADAR
ACROSS SOUTHERN NYE COUNTY AND MOHAVE COUNTY LATE THIS EVENING AND
WHATEVER REMAINS SHOULD FADE AWAY SHORTLY. SHOWERS ARE PRETTY WELL
OVER FOR AREAS FROM LAS VEGAS SOUTHWARD. ISOLATED TO SCATTERED LIGHT
SHOWERS WILL KEEP GOING OVER NORTHERN INYO COUNTY AND THE SOUTHERN
GREAT BASIN ZONES NEAR THE UPPER LOW CENTER BUT ANY PRECIP AMOUNTS
WILL BE MINIMAL. THE POP/WX/SKY/QPF GRIDS WERE ADJUSTED BASED ON
THESE LATEST TRENDS.
&&

.PREV DISCUSSION...
339 PM PDT MON MAY 18 2015

.SHORT TERM...TONIGHT THROUGH WEDNESDAY NIGHT.

CLARK AND LINCOLN COUNTIES HAVE REALLY SEEN AN ACTIVE DAY AS SHOWERS
AND THUNDERSTORMS GOT GOING SHORTLY AFTER DAYBREAK IN THE NORTHEAST
QUADRANT OF A MID/UPPER LEVEL LOW. THE CENTER OF THIS LOW COULD BE
SEEN THIS AFTERNOON ON WATER VAPOR AND SATELLITE OVER DEATH VALLEY
NATIONAL PARK. DESPITE ONLY 0.53 INCH OF PWAT IN THIS MORNING`S NWS
VEGAS SOUNDING AND RELATIVELY LOW-TOPPED CONVECTION, THERE HAVE BEEN
SOME IMPRESSIVE PRECIPITATION TOTALS TODAY WHERE STRONGER STORMS
DEVELOPED OR ACTIVITY TRAINED. A FEW SPOTS IN SUMMERLIN WEST PICKED
UP OVER AN INCH OF RAIN AS WELL AS ONE GUAGE JUST SOUTH OF INSPIRADA
IN HENDERSON. WHILE WIDESPREAD HEAVY RAIN IS NOT EXPECTED THIS
EVENING, ANY SLOWER MOVING OR STRONGER ACTIVITY COULD DUMP A HALF OF
AN INCH OR MORE OF RAIN ESPECIALLY IF IT TRAINS. GIVEN THE
ATMOSPHERE HAS BECOME WORKED OVER IN AND AROUND THE LAS VEGAS VALLEY
EARLIER TODAY, WE THINK THAT THE INTENSITY OF ACTIVITY IMMEDIATELY
IN AND AROUND THE VALLEY SHOULD STAY TOWARD THE LOW-MODERATE END.
HOWEVER, CLOSER TO THE LOW CENTER IN THE NORTHEAST QUADRANT WHERE
ACTIVITY WAS MORE LIMITED EARLIER TODAY, THINGS COULD BE MORE ACTIVE
IN ESMERALDA, EASTERN INYO AND CENTRAL NYE COUNTIES. THE HRRR AND
LOCAL NMM AND ARW MODELS ALL KEY IN ON THESE AREAS FOR ACTIVITY TO
DEVELOP OR PERSIST THIS EVENING AND THUS POPS WERE ADJUSTED UP IN
THESE AREAS. THESE AREAS MAY BE THE SLOWEST TO SEE ACTIVITY END THIS
EVENING WHILE ELSEWHERE THINGS SHOULD END BETWEEN 7 AND 9 PM. LOW
FREEZING LEVELS HAVE ALSO RESULTED IN STRONGER ACTIVITY PRODUCING
HAIL WITH REPORTS EARLIER TODAY AS LARGE AS AN INCH IN DIAMETER IN
THE MOST INTENSE ACTIVITY. IN ADDITION SNOW LEVELS AROUND 8500 FEET
WERE NOTED AND A LIGHT COATING TO AN INCH OR TWO OF SNOW IS POSSIBLE
IN THE HIGHEST ELEVATIONS UNDER ANY SHOWER OR THUNDERSTORM ACTIVITY
OVERNIGHT.

THE LOW CENTER WILL TRANSITION ACROSS THE AREA TONIGHT WHICH WILL
PLACE US ON THE BACK SIDE OF THE LOW FOR TUESDAY. LINGERING ENERGY
AND MID-LEVEL MOISTURE WILL BE ENOUGH TO TOUCH OFF SCATTERED SHOWERS
AND ISOLATED THUNDERSTORMS MAINLY ACROSS THE SOUTHERN GREAT BASIN
BUT OUTSIDE OF LINCOLN AND CENTRAL NYE COUNTIES THE COVERAGE OF
ACTIVITY SHOULD BE LOWER TOMORROW. ONCE AGAIN, LOW FREEZING LEVELS
WILL ALLOW FOR HAIL IN ANY STRONGER ACTIVITY. HIGH TEMPS SHOULD WARM
UP SEVERAL DEGREES AS DRIER AIR WORKS IN AND ERODES AWAY THE CLOUDS
OVER THE MOJAVE DESERT.

ANOTHER LOW WILL APPROACH THE COAST OF CALIFORNIA ON WEDNESDAY. THIS
WILL SPREAD LOTS OF HIGH LEVEL MOISTURE INTO THE AREA AS THE JET
STREAM PASSES BY ACROSS SOCAL INTO ARIZONA RESULTING IN A DECENT
AMOUNT OF CIRRUS CLOUDS TO START TO THE DAY AND AGAIN WEDNESDAY
NIGHT. OTHERWISE, THE BEST MOISTURE AND INSTABILITY WILL BE OVER THE
SOUTHERN SIERRA CREST AND EASTERN SLOPES AS WELL AS ESMERALDA COUNTY
AND A FEW SHOWERS AND THUNDERSTORMS ARE POSSIBLE HERE MAINLY IN THE
AFTERNOON. THE REST OF THE AREA LOOKS DRY WITH WINDS PICKING UP FROM
THE SOUTH IN THE AFTERNOON AND EVENING AND GUSTING TO 20-30 MPH.
HIGH TEMPS SHOULD WARM BACK UP ANOTHER 3-5 DEGREES OVER TUESDAY.
THIS LOW WILL EVENTUALLY LOOP BACK OUT AND MERGE WITH ANOTHER LOW
THAT HEADS TOWARD THE COAST ON THURSDAY.

.LONG TERM...THURSDAY THROUGH MONDAY.

THE NEXT UPPER LOW WILL APPROACH THE CENTRAL CALIFORNIA COAST
THURSDAY. A SHORTWAVE ROTATING AROUND THE LOW WILL MOVE NORTHEAST
INTO CALIFORNIA AND NEVADA DURING THE DAY. AN AREA OF DIFFLUENCE AND
DECENT MID LEVEL MOISTURE WILL LEAD TO A CHANCE OF SHOWERS OVER MUCH
OF INYO COUNTY AND ACROSS ESMERALDA...CENTRAL NYE AND NORTHERN
LINCOLN COUNTIES. THE UPPER LOW WILL MOVE INLAND THURSDAY NIGHT AND
ACROSS SOUTHERN NEVADA INTO NORTHWEST ARIZONA FRIDAY. PRECIPITATION
CHANCES WILL THUS SPREAD EAST ACROSS A GOOD PORTION OF THE FORECAST
AREA...MAINLY NORTH OF INTERSTATE 40. WITH THE LOW MOVING
OVERHEAD...HIGH TEMPERATURES FRIDAY WILL BE SOME 10 TO 15 DEGREES
BELOW NORMAL. PRECIPITATION CHANCES WILL DECREASE AND SHIFT
NORTHEAST FRIDAY NIGHT AS THE LOW STARTS TO EXIT THE AREA.
HOWEVER...A SHORTWAVE TROUGH FOLLOWING BEHIND FROM THE NORTH WILL
BRING A CHANCE OF SHOWERS SATURDAY TO AREAS MAINLY NORTH OF LAS
VEGAS.

FOR SUNDAY THROUGH MONDAY THE MODELS ARE NOT IN VERY GOOD AGREEMENT
BUT IN GENERAL IT LOOKS LIKE THERE WILL BE SOME SORT OF UPPER TROUGH
ROUGHLY OVER NORTHERN NEVADA. THIS WOULD KEEP AT LEAST A SLIGHT
CHANCE OF SHOWERS OVER THE FAR NORTHERN PART OF THE FORECAST AREA
AND I LEFT SLIGHT CHANCE POPS IN FOR THOSE AREAS.
&&

.AVIATION...FOR MCCARRAN...LIGHT NORTHEAST WINDS THAT DEVELOPED
EARLY THIS EVENING SHOULD GIVE WAY TO TYPICAL DIURNAL DIRECTIONS AT
8 KTS OR LESS THE REST OF TONIGHT THROUGH TUESDAY EVENING.
CONDITIONS LOOK DRY IN THE LAS VEGAS VALLEY ON TUESDAY THOUGH,
ISOLATED SHRA/TSRA ARE POSSIBLE IN THE SPRING MOUNTAINS. ADDITIONAL
SHRA AND TSRA CHANCES EXIST FOR FRIDAY AND FRIDAY NIGHT IN THE LAS
VEGAS VALLEY.

FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...ISOLATED SHRA ACTIVITY MAY LINGER THOUGH THE NIGHT IN
THE SOUTHERN GREAT BASIN. SHRA/TSRA WILL AGAIN BE POSSIBLE ON
TUESDAY ESPECIALLY AFTER 18Z NORTH OF KIYK-KDRA-KACZ LINE. WINDS MAY
BE GUSTY AND ERRATIC IN AND NEAR SHRA/TSRA WITH CIGS LOWERING TO 5K-
8K FEET. OTHERWISE LOOK FOR WINDS TO TREND TOWARD TYPICAL DIURNAL
DIRECTIONS AT 10 KTS OR LESS WITH SCT-BKN CLOUDS AOA 10K FEET. &&

.SPOTTER INFORMATION STATEMENT...SPOTTERS ARE ENCOURAGED TO REPORT
ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING
PROCEDURES.
&&

$$

UPDATE/AVIATION...ADAIR
SHORT TERM...STACHELSKI
LONG TERM...HARRISON

FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:

HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER



AREA FORECAST DISCUSSION

NWS BINGHAMTON NY

 249 AM EDT TUE MAY 19 2015

.SYNOPSIS...
WARM AND MUGGY CONDITIONS WILL CONTINUE THROUGH THE NIGHT WITH
ADDITIONAL SHOWERS AND THUNDERSTORMS THROUGH SUNRISE. A COLD
FRONT WILL SWEEP THROUGH THE AREA BY EARLY AFTERNOON TUESDAY WITH
MORE SHOWERS AND STORMS POSSIBLE. MUCH COOLER WEATHER WILL FOLLOW
BEHIND THE FRONT FOR THE MIDDLE AND LATER PART OF THE WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
500 MB HEIGHT FALLS WERE OCCURRING ACROSS THE REGION THIS EVENING
SUPPORTED BY MODEST MID-UPR LEVEL DIVERGENCE ALOFT. A SERIES OF
WEAK MID-LVL IMPULSES ARE PROGGED TO CONTINUE TO SLIDE FROM THE
OHIO VALLEY OFF TO THE NORTHEAST ACROSS WESTERN...THEN CENTRAL NEW
YORK AS THE ENTIRE COMPLEX SYSTEM DRIFTS EASTWARD. MODERATE SFC
BASED INSTABILITY WILL WANE WITH THE LOSS OF SOLAR HEATING...
HOWEVER...ANOMALOUS MOISTURE IN THE BOUNDARY LAYER WILL REMAIN
AND CONTRIBUTE TO A LINGERING INSTABILITY AXIS ACROSS CNTRL NY AND
NRN PA THROUGH THE NIGHT. FORECAST WAS GENERALLY IN GOOD SHAPE TO
ACCOUNT FOR OCCASIONAL ROUNDS OF TSRA THROUGH THE NIGHT. GFS/GGEM
AND HRRR MODELS DO SUGGEST A POTENTIAL ENHANCEMENT OF HEAVIER
STORMS FOCUSING AGAIN FROM SOUTH CNTRL PA INTO CNTRL NY BETWEEN
03Z-09Z WHICH MATCHES WELL WITH THE INSTABILITY AXIS. WE ARE NO
LONGER THINKING ANY ORGANIZED SEVERE WEATHER OVERNIGHT...BUT HEAVY
RAIN POTENTIAL DOES REMAIN. THE QUESTION BEING IS THERE ENOUGH
EVIDENCE AND CONFIDENCE TO HOIST A FLASH FLOOD WATCH AS THERE HAVE
BEEN LOCALIZED AREAS OF EXTREME RAINFALL TODAY...ESPECIALLY HERE
IN THE HOME COUNTY.

RIGHT NOW...WE THINK THE CONVECTIVE STRENGTH WILL BE WEAKER THAN
EARLIER TODAY GIVEN THE LOSS OF BUOYANCY AND REALLY NO SIGNIFICANT
PUNCH TO THE DYNAMIC FORCING. CAN`T TOTALLY RULE OUT SOME HEAVIER
DOWNPOURS AND POTENTIAL OVERWHELMING OF STORM DRAINS IN ANY
DEVELOPED TOWN OR CITY THAT MIGHT GET A SLOW MOVING STORM...BUT
WILL DEAL WITH THAT ON THE SHORT TERM SHOULD IT UNFOLD.

OTHERWISE...JUST MINOR CHANGES THIS EVENING TO ADJUST FOR TEMPS IN
THE MARINE LAYER TO OUR EAST PUSHING WESTWARD.

COLD FRONT THEN SWEEPS INTO AND THROUGH THE REGION ON TUESDAY
MORNING WITH IMPROVING AND COOLER WEATHER DURING THE AFTERNOON.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
QUIET WEATHER IS EXPECTED THROUGH THIS PERIOD WITH MUCH LOWER
TEMPERATURES BEHIND THE COLD FRONT. CANADIAN HIGH PRESSURE WILL
BUILD ACROSS THE GREAT LAKES TOWARD THE MID-ATLANTIC WEDNESDAY
INTO THURSDAY. LOW PRESSURE IS FORECAST TO TRACK FROM THE
TENNESSEE VALLEY TOWARD THE CAROLINAS WEDNESDAY NIGHT INTO
THURSDAY WITH ASSOCIATED RAIN WELL TO OUR SOUTH. GENERALLY WENT
WITH A BLEND OF MAV/MET GUIDANCE FOR TEMPERATURES WEDNESDAY AND
THURSDAY WHICH YIELDED UNSEASONABLY COOL HIGHS IN THE MID 50S TO
MID 60S ON WEDNESDAY... WARMING A BIT INTO THE 60S ON THURSDAY.
LOWS WEDNESDAY NIGHT WILL RANGE FROM THE MID 30S TO MID 40S WITH A
TOUCH OF FROST NOT OUT OF THE QUESTION IN NORMALLY COOLER
LOCATIONS.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
0245 AM UPDATE...WE ONLY MADE A COUPLE MINOR CHANGES TO THE
PREVIOUS FORECAST ISSUED MONDAY AFTERNOON. THE FIRST WAS TO LOWER
HIGH TEMPS A COUPLE DEGREES FOR FRIDAY AS A COLD FRONT PUSHES
THROUGH THE AREA AND THE SECOND CHANGE WAS TO REMOVE THE MENTION
OF PRECIP FOR SUNDAY.

PREVIOUS DISCUSSION...QUIET PD FOR THE XTNDD. SCNDRY FNT APRCHS
THE AREA ON FRI AND MGT GENERATE A FEW SHWRS OVER THE NRN AREAS
WITH PEAK HTG. HGTS BLDS AGAIN AS SFC HIPRES BLDS IN FOR THE
WEEKEND SO XPCT DRY WEATHER INTO SUNDAY. WITH THE TROFINESS ALOFT
IN THE PD...TEMPS WILL BE A BIT COOLER THAN NRML DESPITE THE
DAYTIME SUN.

&&

.AVIATION /07Z TUESDAY THROUGH SATURDAY/...
EXPECT CONTINUING RESTRICTIONS OVERNIGHT. FOR KBGM/KAVP, IFR CIGS
WILL PERSIST WITH KBGM BELOW ALTERNATE MINS. FOR KITH/KELM/KSYR
EXPECT A REDUCTION IN VISBYS NEAR SUNRISE AS CLEARING STARTS TO
MAKE IT IN AND ALLOW FOR AREAS OF FOG TO DEVELOP. EXPECT LOW
CLOUDS AND FOG TO MIX OUT BY LATER TUESDAY MORNING INTO THE
AFTERNOON WITH VFR EXPECTED BY MID AFTERNOON. HOWEVER AS THE COLD
FRONT CROSSES THE AREA AROUND MIDDAY INTO THE EARLY AFTERNOON THERE
MAY BE SOME ADDITIONAL SCATTERED SHOWERS AND THUNDERSTORMS THAT
COULD POTENTIALLY EFFECT KSYR/KRME/KBGM/KAVP. THESE COULD PRODUCE
GUSTY WINDS.

S/SE WINDS OVERNIGHT AROUND 5-10 KNOTS BECOMING SOUTHWEST AROUND
MID MORNING AT 10 KNOTS THEN NW BY AFTERNOON AT 10-15 KNOTS WITH
GUSTS AROUND 25 KNOTS.

.OUTLOOK...

TUE NGT-SAT...MAINLY VFR.

&&

.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.

&&

$$
SYNOPSIS...JAB
NEAR TERM...JAB
SHORT TERM...MSE
LONG TERM...DGM/PCF
AVIATION...PCF



AREA FORECAST DISCUSSION

NWS BINGHAMTON NY

 154 AM EDT TUE MAY 19 2015

.SYNOPSIS...
WARM AND MUGGY CONDITIONS WILL CONTINUE THROUGH THE NIGHT WITH
ADDITIONAL SHOWERS AND THUNDERSTORMS THROUGH SUNRISE. A COLD
FRONT WILL SWEEP THROUGH THE AREA BY EARLY AFTERNOON TUESDAY WITH
MORE SHOWERS AND STORMS POSSIBLE. MUCH COOLER WEATHER WILL FOLLOW
BEHIND THE FRONT FOR THE MIDDLE AND LATER PART OF THE WEEK.

&&

.NEAR TERM /THROUGH TODAY/...
500 MB HEIGHT FALLS WERE OCCURRING ACROSS THE REGION THIS EVENING
SUPPORTED BY MODEST MID-UPR LEVEL DIVERGENCE ALOFT. A SERIES OF
WEAK MID-LVL IMPULSES ARE PROGGED TO CONTINUE TO SLIDE FROM THE
OHIO VALLEY OFF TO THE NORTHEAST ACROSS WESTERN...THEN CENTRAL NEW
YORK AS THE ENTIRE COMPLEX SYSTEM DRIFTS EASTWARD. MODERATE SFC
BASED INSTABILITY WILL WANE WITH THE LOSS OF SOLAR HEATING...
HOWEVER...ANOMALOUS MOISTURE IN THE BOUNDARY LAYER WILL REMAIN
AND CONTRIBUTE TO A LINGERING INSTABILITY AXIS ACROSS CNTRL NY AND
NRN PA THROUGH THE NIGHT. FORECAST WAS GENERALLY IN GOOD SHAPE TO
ACCOUNT FOR OCCASIONAL ROUNDS OF TSRA THROUGH THE NIGHT. GFS/GGEM
AND HRRR MODELS DO SUGGEST A POTENTIAL ENHANCEMENT OF HEAVIER
STORMS FOCUSING AGAIN FROM SOUTH CNTRL PA INTO CNTRL NY BETWEEN
03Z-09Z WHICH MATCHES WELL WITH THE INSTABILITY AXIS. WE ARE NO
LONGER THINKING ANY ORGANIZED SEVERE WEATHER OVERNIGHT...BUT HEAVY
RAIN POTENTIAL DOES REMAIN. THE QUESTION BEING IS THERE ENOUGH
EVIDENCE AND CONFIDENCE TO HOIST A FLASH FLOOD WATCH AS THERE HAVE
BEEN LOCALIZED AREAS OF EXTREME RAINFALL TODAY...ESPECIALLY HERE
IN THE HOME COUNTY.

RIGHT NOW...WE THINK THE CONVECTIVE STRENGTH WILL BE WEAKER THAN
EARLIER TODAY GIVEN THE LOSS OF BUOYANCY AND REALLY NO SIGNIFICANT
PUNCH TO THE DYNAMIC FORCING. CAN`T TOTALLY RULE OUT SOME HEAVIER
DOWNPOURS AND POTENTIAL OVERWHELMING OF STORM DRAINS IN ANY
DEVELOPED TOWN OR CITY THAT MIGHT GET A SLOW MOVING STORM...BUT
WILL DEAL WITH THAT ON THE SHORT TERM SHOULD IT UNFOLD.

OTHERWISE...JUST MINOR CHANGES THIS EVENING TO ADJUST FOR TEMPS IN
THE MARINE LAYER TO OUR EAST PUSHING WESTWARD.

COLD FRONT THEN SWEEPS INTO AND THROUGH THE REGION ON TUESDAY
MORNING WITH IMPROVING AND COOLER WEATHER DURING THE AFTERNOON.

&&

.SHORT TERM /TONIGHT THROUGH THURSDAY/...
QUIET WEATHER IS EXPECTED THROUGH THIS PERIOD WITH MUCH LOWER
TEMPERATURES BEHIND THE COLD FRONT. CANADIAN HIGH PRESSURE WILL
BUILD ACROSS THE GREAT LAKES TOWARD THE MID-ATLANTIC WEDNESDAY
INTO THURSDAY. LOW PRESSURE IS FORECAST TO TRACK FROM THE
TENNESSEE VALLEY TOWARD THE CAROLINAS WEDNESDAY NIGHT INTO
THURSDAY WITH ASSOCIATED RAIN WELL TO OUR SOUTH. GENERALLY WENT
WITH A BLEND OF MAV/MET GUIDANCE FOR TEMPERATURES WEDNESDAY AND
THURSDAY WHICH YIELDED UNSEASONABLY COOL HIGHS IN THE MID 50S TO
MID 60S ON WEDNESDAY... WARMING A BIT INTO THE 60S ON THURSDAY.
LOWS WEDNESDAY NIGHT WILL RANGE FROM THE MID 30S TO MID 40S WITH A
TOUCH OF FROST NOT OUT OF THE QUESTION IN NORMALLY COOLER
LOCATIONS.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
QUIET PD FOR THE XTNDD. SCNDRY FNT APRCHS THE AREA ON FRI AND MGT
GENERATE A FEW SHWRS OVER THE NRN AREAS WITH PEAK HTG. HGTS BLDS
AGAIN AS SFC HIPRES BLDS IN FOR THE WEEKEND SO XPCT DRY WEATHER
INTO SUNDAY. WITH THE TROFINESS ALOFT IN THE PD...TEMPS WILL BE A
BIT COOLER THAN NRML DESPITE THE DAYTIME SUN.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
EXPECT CONTINUING RESTRICTIONS OVERNIGHT. FOR KBGM/KAVP, IFR CIGS
WILL PERSIST WITH KBGM BELOW ALTERNATE MINS. FOR KITH/KELM/KSYR
EXPECT A REDUCTION IN VISBYS NEAR SUNRISE AS CLEARING STARTS TO
MAKE IT IN AND ALLOW FOR AREAS OF FOG TO DEVELOP. EXPECT LOW
CLOUDS AND FOG TO MIX OUT BY LATER TUESDAY MORNING INTO THE
AFTERNOON WITH VFR EXPECTED BY MID AFTERNOON. HOWEVER AS THE COLD
FRONT CROSSES THE AREA AROUND MIDDAY INTO THE EARLY AFTERNOON THERE
MAY BE SOME ADDITIONAL SCATTERED SHOWERS AND THUNDERSTORMS THAT
COULD POTENTIALLY EFFECT KSYR/KRME/KBGM/KAVP. THESE COULD PRODUCE
GUSTY WINDS.

S/SE WINDS OVERNIGHT AROUND 5-10 KNOTS BECOMING SOUTHWEST AROUND
MID MORNING AT 10 KNOTS THEN NW BY AFTERNOON AT 10-15 KNOTS WITH
GUSTS AROUND 25 KNOTS.

.OUTLOOK...

TUE NGT-SAT...MAINLY VFR.

&&

.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.

&&

$$
SYNOPSIS...JAB
NEAR TERM...JAB
SHORT TERM...MSE
LONG TERM...DGM
AVIATION...PCF/RRM



AREA FORECAST DISCUSSION

NWS CHARLESTON WV

 226 AM EDT TUE MAY 19 2015

.SYNOPSIS...
COLD FRONT PUSHES EAST THIS MORNING. UPPER LEVEL DISTURBANCE
PASSES BY WEDNESDAY NIGHT INTO THURSDAY. WEAK DRY COLD FRONT
PUSHES SOUTH FRIDAY. HIGH PRESSURE IN CONTROL FOR SATURDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
SENT A QUICK UPDATE TO ADJUST POPS PER LATEST RADAR IMAGES. A
BROKEN LINE OF SHOWERS...WITH FEW LIGHTNING STRIKES TO OUR FAR
SOUTH OVER THE WESTERN SLOPES OF WV AND EXTREME SOUTHWEST VA...MOVING
EAST AROUND 15 KNOTS. BEHIND THIS LINE RADAR LOOKS DRY EVEN ALONG
THE UPCOMING COLD FRONT. THEREFORE...KEPT HIGH CHANCE WITH THE
SHOWERS AND REMOVE CHANCES BEHIND IT. REST OF FORECAST REMAINS ON
TRACK.

PREVIOUS DISCUSSION BELOW...
815 PM UPDATE...
FINE TUNED POPS TO KEY IN MAINLY ON BROKEN LINE OF SHOWERS
CROSSING THE OHIO RIVER AS OF 00Z. THE LINE CLOSER TO THE FRONT
WILL MOSTLY FALL APART BEFORE REACHING THE FCST AREA OVERNIGHT
TONIGHT. THE THREAT FOR THUNDER OVERALL QUICKLY WANES TONIGHT. THE
COLD FRONT CROSSES/MIXES THROUGH TUE MORNING.

PREV DISCN...
SCATTERED POPCORN CONVECTION IS BEING SEEN ACROSS THE AREA THIS
AFTERNOON...AS MOIST AIR MASS HEATS UP IN BOUNDARY LAYER HEATING.
OTHERWISE...SLIGHTLY MORE ORGANIZED CONVECTION NOTED OVER EASTERN
KY AND SOUTHERN OH...AS WEAK VORT FEATURE APPROACHES FROM THE
WEST. IT APPEARS THE LATEST RAP RUNS HAVE A FAIR HANDLE ON THE
OVERALL MASS FIELDS AND THE PROGRESSION OF FEATURES ACROSS
TONIGHT. USED A RATHER BROAD BRUSH APPROACH TO COVER POPS THIS
AFTERNOON AND THIS EVENING. HAVE FRONT CROSSING LATE TONIGHT AND
EARLY MORNING. SPEED UP TIMING SLIGHTLY...BY AN HOUR OR TWO...NOT
MUCH TO REALLY MAKE A CHANGE TO THE OVERALL FORECAST.

FOR TEMPS...WILL SEE A FEW DEGREES OF COOLING TUESDAY OVER TODAYS
HIGHS AS COOLER AIR MASS MOVES IN...WITH DRYING OF THE ATMOSPHERIC
COLUMN.

&&

.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
REGION SHOULD START OUT DRY AS SURFACE HIGH PRESSURE TRIES TO TAKE
CONTROL OF THE WEATHER ACROSS THE AREA.  HOWEVER...SEVERAL UPPER
LEVEL DISTURBANCES WILL MOVE EAST.  THESE FEATURES MAY RESULT IN A
FEW SHOWERS WEDNESDAY NIGHT INTO EARLY THURSDAY.  IN RESPONSE...HAVE
INCLUDED SLIGHT CHANCE POPS.

DRY CONDITIONS SHOULD THEN RETURN AS THE LAST OF THE DISTURBANCES
MOVE EAST.

MODELS SUGGEST A COLD FRONT WILL APPROACH THE AREA FROM THE NORTH ON
FRIDAY.  LITTLE MOISTURE IS FORECAST WITH THIS FEATURE.  SO OTHER
THAN A FEW MORE CLOUDS...EXPECT DRY WEATHER FOR FRIDAY.

HIGH TEMPERATURES ON WEDNESDAY AND THURSDAY WILL BE QUITE COOL.
TEMPERATURES ON FRIDAY WILL BE A LITTLE WARMER...WITH READINGS
CLOSER TO SEASONAL AVERAGES. GENERALLY WENT WITH A BLEND OF MET/MAV
NUMBERS...AND THEN THE MEX/ECMWF NUMBERS FOR THE LATTER PART OF THE
PERIOD.

&&

.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
A HIGH BEGINS TO BUILD IN THE GULF OF MEXICO ON SUNDAY...MIGRATES
EAST AND TRIES TO STRENGTHEN. THIS WILL LEAD TO A POTENTIALLY
MESSY FORECAST FOR THE OHIO VALLEY WITH SEVERAL UPPER LEVEL
DISTURBANCES ROTATING AROUND THE CANADIAN LOW PRESSURE SYSTEMS.
HAVE CHANCE POPS ON SUNDAY AND MONDAY AS EXPECT MOISTURE TO BECOME
TRAPPED UNDER THE HIGH. THERE REALLY ISN/T ANYTHING SIGNIFICANT TO
FOCUS ON TO TIME THESE EVENTS.

WENT WITH A BLEND OF GUIDANCE FOR TEMPERATURES. TEMPERATURES WILL
RISE THROUGH THE EXTENDED PART OF THE FORECAST.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
SATELLITE IMAGES SHOW AN AREA OF CLEAR SKIES BETWEEN THE BATCH OF
SHOWERS CROSSING THE EASTERN MOUNTAINS ATTM AND THE COLD FRONT
CURRENTLY OVER CENTRAL OH. WITH DEWPOINTS IN THE MID 60S...THIS AREA OF
CLEARING COULD ALLOW RADIATIONAL COOLING TO REACH SATURATION FOR
FOG OR LOW STRATUS FORMATION OVERNIGHT. THEREFORE...CODED IFR
CEILINGS AT CKB...EKN AND HTS WHERE DEWPOINT DEPRESSION IS ALREADY
ZERO. OTHER SITES COULD EXPERIENCE MVFR CEILINGS OR VISIBILITIES
OVERNIGHT.

THE COLD FRONT IS EXPECTED TO REACH SOUTHEAST OH AROUND 12Z THIS
MORNING. SOME LOW STRATUS CLOUDS CAN BE EXPECTED ALONG ITS PATH
WITH NO PCPN. THE MORNING STRATUS WILL THEN MIX HIGHER BEFORE
MIXING OUT ALTOGETHER BY MID MORNING.

CALM FLOW EXPECTED AT MOST SITES OVERNIGHT...BECOMING LIGHT W TO
NW ON TUESDAY. IT MAY STRENGTHEN AND BECOME JUST A BIT GUSTY TUE
AFTERNOON.

FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z WEDNESDAY...

FORECAST CONFIDENCE: MEDIUM.

ALTERNATE SCENARIOS: FOG AND STRATUS FORMATION OVERNIGHT AND BREAK
UP TUE MORNING MAY VARY.  THERE MAY BE MORE IFR THAN FCST ON
EITHER...ESPECIALLY E OF THE OHIO RIVER.

EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH:   TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW:    TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.

DATE                              TUE 05/19/15
UTC 1HRLY       06   07   08   09   10   11   12   13   14   15   16   17
EDT 1HRLY       02   03   04   05   06   07   08   09   10   11   12   13
CRW CONSISTENCY  M    M    M    M    M    H    H    H    H    H    M    H
HTS CONSISTENCY  M    M    M    M    M    M    M    M    M    M    M    H
BKW CONSISTENCY  M    M    H    H    M    M    M    H    H    H    H    H
EKN CONSISTENCY  M    H    M    L    M    L    L    L    H    H    H    H
PKB CONSISTENCY  H    H    M    M    M    M    M    M    M    M    M    H
CKB CONSISTENCY  M    M    M    H    H    H    H    H    H    H    H    H

AFTER 06Z WEDNESDAY...
FOG/LOW CLOUDS POSSIBLE OVERNIGHT TUE NT INTO WED MORNING AND
POSSIBLY AGAIN OVERNIGHT THU NT INTO FRI MORNING.

&&

.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.

&&

$$
SYNOPSIS...JSH/ARJ
NEAR TERM...ARJ/TRM
SHORT TERM...JSH
LONG TERM...FB
AVIATION...ARJ









AREA FORECAST DISCUSSION

NWS MEDFORD OR

 901 PM PDT MON MAY 18 2015

.DISCUSSION...THE FORECAST WAS UPDATED TO ADJUST THE PROBABILITY
OF PRECIPITATION AND PRECIPITATION AMOUNTS FORECAST FOR TONIGHT
THROUGH TUESDAY NIGHT...MAINLY TO SHAVE BACK THE AMOUNTS EXPECTED
FROM THE COAST INTO WESTERN AND CENTRAL DOUGLAS COUNTY AND ALSO
OVER LAKE COUNTY. THESE CHANGES ARE IN ACCORDANCE WITH THE 18Z GFS
AND RECENTLY ARRIVED 00Z NAM DATA.

COMPARED TO YESTERDAY AFTERNOON AND EVENING, SHOWERS WERE MORE
NUMEROUS BUT THUNDERSTORMS WERE LESS NUMEROUS. THE LARGE MAJORITY
OF THE THUNDERSTORMS OCCURRED BETWEEN 1 PM AND 4PM WITH ABOUT 135
LIGHTNING STRIKES COMPARED TO THE MORE THAN 300 YESTERDAY. SLOW
MOVING AND VERY MOIST SHOWERS ARE STILL MOST WIDESPREAD OVER THE
SISKIYOU MOUNTAINS AND HIGHER TERRAIN OF SISKIYOU COUNTY. SEVERAL
RAWS SITES IN THAT AREA HAVE RECEIVED AROUND 0.25 TO 0.60 INCHES
OF RAIN.

ANOTHER FEW BOLTS OF LIGHTNING ARE POSSIBLE DURING THE REMAINDER
OF THE EVENING, BUT ACTIVITY IS WANING WITH THE DECREASE IN
INSTABILITY DUE TO SURFACE COOLING. BUT, A SHORTWAVE ROTATING FROM
NORTHEAST TO SOUTHWEST ACROSS OUR AREA WILL CONTINUE SCATTERED TO
NUMEROUS SHOWERS OVERNIGHT INTO TUESDAY MORNING. THE THUNDERSTORM
FORECAST FOR TUESDAY AFTERNOON AND EVENING LOOKS ON TRACK...WITH
THE THREAT FARTHER EAST THAN IT WAS TODAY...SOUTH AND EAST OF THE
ROGUE VALLEY...DUE TO THE UPPER TROUGH TRACKING FARTHER EAST INTO
THE GREAT BASIN.

THE PATTERN STILL LOOKS TO REMAIN SIMILARLY ACTIVE WITH OCCASIONAL
SHOWERS...MOST NUMEROUS AND MAINLY OVER THE HIGHER TERRAIN DURING
THE AFTERNOON AND EVENING HOURS THROUGH FRIDAY. AT THIS EARLY
JUNCTURE, MODEL DIFFERENCES ARE SUBSTANTIAL REGARDING THE HOLIDAY
WEEKEND FORECAST. BUT, THE PROBABILITIES ARE SHADED TOWARDS A
WARMER AND DRIER PATTERN.

&&

.AVIATION...FOR THE 19/00Z TAF CYCLE...CURRENT RADAR IMAGERY SHOWS
MORE SHOWERS THAN THUNDERSTORMS ACROSS THE CWA.  LOOK FOR THE
POTENTIAL FOR THUNDERSTORMS TO DIMINISH THIS EVENING. RIGHT NOW VFR
CIGS ARE STILL PREVAILING, YET MVFR CIGS SHOULD DEVELOP LATER
TONIGHT INTO TUESDAY MORNING UNDER A STABLE AIR MASS WITH PLENTY OF
LOW LEVEL MOISTURE.  VFR AND BKN TO OVC DECKS WILL CONTINUE TOMORROW
WITH PLENTY OF MISTURE MOISTURE AND VERTICAL MOTION. /CS

&&

.MARINE...UPDATED 200 PM PDT, MONDAY 18 MAY 2015...A PATTERN OF WEAK
HIGH PRESSURE OFFSHORE AND WEAK LOW PRESSURE INLAND WILL PERSIST
MOST OF THIS WEEK WITH LIGHT TO MODERATE NORTH WINDS AND NORTHWEST
SWELL OVER THE WATERS. WINDS WILL APPROACH SMALL CRAFT ADVISORY
LEVELS ON TUESDAY EVENING AND WEDNESDAY MORNING SOUTH OF CAPE
BLANCO.  AFTER THIS NORTH WINDS AROUND 10-20 KTS WILL CONTINUE INTO
THWE WEEKEND. /CS


&&

.PREV DISCUSSION... /ISSUED 521 PM PDT MON MAY 18 2015/

SHORT TERM...MOISTURE CONTINUES TO ROTATE IN OVER OUR AREA FROM
THE EAST AS AN UPPER LOW MOVES INTO THE GREAT BASIN. DYNAMICS ARE
WEAK, BUT THERE IS PLENTY OF INSTABILITY PRESENT FROM THE CASCADE
CREST AND SISKIYOUS EASTWARD, AND NUMEROUS SHOWERS AND ISOLATED
THUNDERSTORMS HAVE ALREADY DEVELOPED. THIS CONVECTION WILL
INCREASE IN COVERAGE AND MIGRATE TOWARD THE WEST THROUGH THE
AFTERNOON. CONVECTION IS ALREADY TRYING TO SPILL OVER ONTO THE
WEST SIDE, BUT IT IS BEING INHIBITED BY THE LITTLE REMAINING CAP.
THE SUN IS PEAKING THROUGH IN THE WEST SIDE VALLEYS AND THE
SURFACE HEATING WILL BREAK THE CAP PRETTY SOON. MESOANALYSIS
INDICATES WE`VE BUILT 500-1000 J/KG OF SURFACE BASED CAPE
OVER JACKSON AND JOSEPHINE COUNTIES ALREADY, WHICH SHOULD BE
RELEASED EVENTUALLY, AND RESULT IN SHOWERS AND THUNDERSTORMS THERE
AS WELL. LATEST RAP AND HRRR GUIDANCE ACTUALLY SHOWS QUITE A LOT
OF CONVECTION OVER THE ROGUE AND ILLINOIS VALLEYS LATER THIS
AFTERNOON. THEY MAY BE A BIT OVERDONE, BUT PEOPLE IN THESE AREAS
SHOULD KEEP AN EYE ON THE SKY. AS OPPOSED TO YESTERDAY, THE SUN IS
ALSO POKING OUT IN THE UMPQUA, AND THEY DO STAND A BETTER CHANCE
OF SEEING SOME THUNDERSTORMS THIS AFTERNOON AS WELL. THERE IS A
LOT OF MOISTURE IN THE PROFILE (PRECIPITABLE WATER IS NEAR AN
INCH) AND THUS ANY OF THESE STORMS WILL BE CAPABLE OF PRODUCING
SMALL HAIL AND HEAVY DOWNPOURS. WITH LITTLE WIND ALOFT TO SPEAK
OF, STRONG WINDS SHOULDN`T BE MUCH OF A CONCERN, BUT WE COULD SEE
GUSTY WINDS AROUND STORMS.

THINGS WILL STABILIZE TONIGHT AS THE BOUNDARY LAYER COOLS, BUT
SHOWERS ARE LIKELY TO CONTINUE OVERNIGHT ALONG THE MOUNTAINS AND
EAST SIDE. AS BROAD TROUGHING REMAINS OVER THE REGION, WE EXPECT
TO REPEAT THIS BASIC DIURNAL PATTERN OF NIGHT TIME SHOWERS AND
MORE WIDESPREAD SHOWERS AND THUNDERSTORMS IN THE AFTERNOONS
TOMORROW THROUGH THURSDAY. WE SHOULD GRADUALLY BECOME MORE STABLE
ON THE WEST SIDE, SO THUNDERSTORMS BECOME LESS OF AN ISSUE. ONE
BIGGER CHANGE I MADE WAS TO INCREASE POPS OVER THE WEST SIDE
TUESDAY NIGHT INTO WEDNESDAY MORNING AS ALL THE MODELS ARE SHOWING
A DEFORMATION BAND FORMING OVER THE AREA. -WRIGHT

LONG TERM...THE MODELS SHOW THE WEAK UPPER LOW MOVING INTO
ARIZONA WITH WEAK RIDGING BUILDING OFFSHORE. THE GFS SHOWS MORE
RIDGING COMPARED TO THE EC AND BOTH CONTINUE TO SHOW QPF OVER MOST
OF THE AREA. I SUSPECT THE QPF MAY BE OVERDONE NOT ONLY WITH
AMOUNTS, BUT ALSO THE COVERAGE. THUS HAVE SCALED BACK ON POPS FOR
FRIDAY. ANOTHER WEAK UPPER LOW MOVES INTO THE AREA SATURDAY, BUT
THIS ONE WILL BE COMING IN FROM THE NORTHWEST AND IS NOT EXPECTED
TO HAVE ANY OVER WATER TRAJECTORY, THEREFORE MOISTURE WILL BE
LIMITED AND ANY SHOWERS SHOULD BE ISOLATED AND EAST OF THE
CASCADES. THE EC AND GFS DISAGREE WITH THE PROGRESSION OF THE
UPPER LOW SUNDAY AND THE UPSTREAM UPPER LOW. THE GFS KEEPS THE
UPPER LOW OVER THE AREA SUNDAY WHILE THE EC MOVES IT INTO NORTHERN
CAL. FOR NOW WE`LL GO WITH A BLEND BETWEEN THE TWO AND KEEP A
SLIGHT CHANCE OF SHOWERS EAST OF THE CASCADES. THE ENSEMBLE MEAN
SHOWS A LARGE SPREAD IN THIS TIME PERIOD WHICH YIELDS LOWER
CONFIDENCE IN THE FORECAST. -PETRUCELLI

FIRE WEATHER...UPDATED 200 PM PDT, MONDAY 18 MAY 2015...AN UPPER
LOW CENTERED JUST EAST OF THE BAY AREA IS SENDING MOISTURE NORTHEAST
TOWARDS THE AREA. SO FAR ISOLATED STORMS HAVE BEEN CONFINED TO THE
CASCADES EAST, BUT THEY ARE EXPECTED TO BECOME MORE FREQUENT AS THE
AFTERNOON PROGRESSES INTO THIS EVENING. THE LATEST MESOSCALE  ANALYSIS
SHOWS HIGHER CAPE VALUES WEST OF THE CASCADES COMPARED TO YESTERDAY
AND THE MOIST LAYER IS MUCH DEEPER ALL THE WAY UP TO 400 MB BASED IN
THIS MORNINGS SOUNDING. THE 700 MB FLOW WILL BE FROM THE EAST TO
NORTHEAST, THERE IS A BETTER CHANCE FOR SHOWERS AND ISOLATED STORMS
TO MAKE THEIR WAY WEST OF THE CASCADES. WITH PLENTY OF MOISTURE
AVAILABLE, THUNDERSTORMS ARE LIKELY TO BE RAIN PRODUCERS AND THEY
WILL BE SLOW MOVERS. SO HEAVY RAINFALL IS POSSIBLE.

THUNDERSTORMS WILL DECREASE THIS EVENING AND END TONIGHT, BUT WE`LL
CONTINUE TO GET MUCH NEEDED RAIN SHOWERS OVERNIGHT TONIGHT.

THE UPPER LOW WILL MOVE EAST AND WEAKEN TUESDAY WITH THE BEST CHANCE
FOR THUNDERSTORMS ALONG AND EAST OF THE CASCADES. THE ATMOSPHERE IS
EXPECTED TO BE MORE STABLE WEST OF THE CASCADES DUE TO A MARINE
INFLUENCE, SO WERE ONLY EXPECTING SHOWERS. -PETRUCELLI

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.

CA...NONE.

PACIFIC COASTAL WATERS...NONE.

$$

DW/MAP/CZS



AREA FORECAST DISCUSSION

NWS STATE COLLEGE PA

 512 AM EDT TUE MAY 19 2015

.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS CENTRAL PENNSYLVANIA TODAY WITH A
MARGINAL/ISOLATED SEVERE WEATHER RISK FROM THE EASTERN COAL REGION
INTO THE POCONOS. A COOLER AND MAINLY DRY WEATHER PATTERN WITH
NEAR TO BELOW NORMAL TEMPERATURES WILL GRIP THE REGION FROM
WEDNESDAY INTO THE WEEKEND...FOLLOWED BY A GRADUAL WARMING TREND
WITH UNSETTLED CONDITIONS THROUGH EARLY NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
09Z RADAR SHOWS WHAT IS LEFT OF MEASURABLE SHOWERS MOVG EWD ALONG
RDG-LNS LINE. WILL TAPER DOWN POPS THROUGH MID MORNING BASED ON
RADAR TRENDS AND HRRR. SUBTLE BACKDOOR TYPE FRONT HAS ALLOWED
MARINE AIR/EASTERLY LLVL FLOW TO REACH AS FAR WEST AS THE SUSQ
RIVER WITH WDSPRD LOW CIGS AND FOG EXPECTED TO PERSIST THROUGH
DAYBREAK. TO THE WEST ALONG THE ALLEGHANY FRONT...WEAK BUT MOIST
UPSLOPE IS PROMOTING LOW CIGS AND FOG ALONG THE RT 219 CORRIDOR.

SHORTWAVE CURRENTLY MOVING THROUGH THE UPPER GREAT LAKES WILL
TEAM WITH ADDITIONAL ENERGY DROPPING DOWN AROUND THE HUDSON BAY
UPPER TROUGH TO FLATTEN THE ANOMALOUS RIDGE OVER THE NORTHEASTERN
U.S. ONCE THE LOW CLOUDS/FOG BURN OFF THIS MORNING...STRONG PRE-
FRONTAL BOUNDARY LAYER WARMING SHOULD PROVE MORE THAN ADEQUATE FOR
CONVECTION WITH HRRR SHOWING DEVELOPMENT EAST OF THE SUSQ RIVER
BY 18-19Z. THE SPC DAY 1 MARGINAL RISK JUST CLIPS EAST-CENTRAL PA
FROM THE COAL REGION ENEWD INTO THE POCONOS WITH INCREASING SHEAR
TO THE NORTH. HOWEVER DESPITE WEAKER FLOW ALOFT...CANT RULE OUT
THREAT FOR GUSTY WINDS/SMALL HAIL IN MORE CAPE-DRIVEN STORMS
WITHIN STEEP LLVL LAPSE RATE ENVIRONMENT OVER THE LWR SQV. HEAVY
DOWNPOURS COULD POSE MINOR FLOOD THREAT PROBABLY MORE SO CONFINED
TO URBAN/POOR DRAINAGE AREAS VS. SMALL STREAMS AND CREEKS GIVEN
DRY ANTECEDENT CONDITIONS AND BELOW NORMAL STREAM FLOWS FOR THIS
TIME OF YEAR. ANY EARLY EVENING ACTIVITY OVER FAR ERN SXNS SHOULD
PUSH OUT OF THE CWA AFTER 00Z AS NOTICEABLY DRIER AIR SPREADS
ACROSS THE AREA IN THE WAKE OF THE COLD FRONT.

&&

.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
A COOLER BROAD CYCLONIC FLOW WILL BEGIN TO GRIP THE REGION ON
WEDNESDAY WITH DAYTIME HIGHS SOME 15-20F COOLER THAN TODAY. THE
COOLER AIR ALOFT SHOULD PROMOTE AFTN CU DEVELOPMENT WITH A NW
BREEZE ADDING TO THE RELATIVE CHILL. THE MODELS SHOW A SHORTWAVE
TROUGH MOVING QUICKLY ESEWD FROM THE UPPER GREAT LAKES THROUGH
CENTRAL APPALACHIANS AND NORTHERN MID ATLANTIC STATES THU-FRI WITH
SOME SHOWERS POSSIBLE ON THU. A SFC LOW IS FCST TO EMERGE OFF THE
CAROLINAS INTO FRIDAY WITH SOME SPREAD IN THE GUIDANCE...OWING TO
VARIABILITY IN THE HANDLING OF THE PARENT SHORTWAVE. A SECONDARY
COLD FRONT SHOULD CROSS THE AREA ON FRIDAY FOLLOWED BY ANOTHER
SHOT OF COOL AIR. CONFIDENCE REMAINS ON THE LOW SIDE FOR FROST
THU MORNING IN THE NORTH AS THE PATTERN DOES NOT LOOK FAVORABLE
OR CONDUCIVE.

&&

.LONG TERM /SATURDAY THROUGH MONDAY/...
CONFIDENCE IN FROST POTENTIAL IS MUCH HIGHER ON SATURDAY MORNING
OVER THE NORTH-CNTRL ZONES WITH A LARGE AREA OF HP FCST TO SETTLE
OVER CENTRAL PA. WILL ADD FROST WORDING TO THE HWO FOR THE 3 ZONES
THAT ARE STILL NOT IN THE GROWING SEASON /MCKEAN-POTTER-ELK/. DRY
WX SHOULD HOLD ON UNTL EARLY NEXT WEEK AS THE UPPER RIDGE BUILDS
AGAIN OVER THE ERN U.S. AN E-W FRONTAL BOUNDARY COULD BE A FOCUS
FOR PCPN AS IT PIVOTS AND LIFTS NWD IN A SIMILAR FASHION TO THIS
PAST WEEKEND. CLOSELY FOLLOWED THE ROBUST NATIONAL SUPERBLEND
PROTOTYPE GUIDANCE FOR TEMPERATURES WHICH FAVORS A GRADUAL
WARMING TREND FOR THE AREA BEYOND THE END OF THE PERIOD.

&&

.AVIATION /09Z TUESDAY THROUGH SATURDAY/...
AN UNSTABLE AIR MASS AHEAD OF AN APPROACHING COLD FRONT WILL
ALLOW FOR SCATTERED SHRA TO CONTINUE TO MOVE ACROSS CENTRAL PA
OVERNIGHT. ANY OF THESE SHRA COULD PRODUCE BRIEF VIS REDUCTIONS.

HOWEVER...THE MAIN AVIATION CONCERN OVERNIGHT AND THROUGH THE
FIRST HALF OF THE MORNING WILL BE THE DEVELOPING LOW CIGS ACROSS
CENTRAL PA. THE LOW CIGS IN EASTERN PA IS A RESULT OF MARINE AIR
FLOWING OFF THE ATLANTIC OCEAN...COUPLED WITH THE AMPLE LOW LEVEL
MOISTURE PROVIDED BY THE SHOWERS FROM EARLIER.

IFR CIGS ARE ALREADY PRESENT ACROSS MUCH OF EASTERN AND WESTERN
PA AT 06Z...WITH AOO AND UNV THE LONE HOLD OUTS. NEAR TERM MDL
DATA SUPPORT THESE LOW CIGS CONTINUING THROUGH 12Z. THE WESTERN
TAF SITES THAT ARE IFR ARE DUE TO A PLUME OF MOISTURE AHEAD OF
APPROACHING COLD FRONT THAT WILL ASCEND THE W MTNS...LIKELY
RESULTING IN IFR CIGS AT KBFD/KJST OVERNIGHT. BOTH THE SREF AND
LATEST HRRR SUPPORT THIS SCENARIO. MOST FAVORABLE CONDS OVERNIGHT
SHOULD BE AT KAOO/KUNV...WHERE SIG REDUCTIONS APPEAR UNLIKELY.

LOW CIGS ACROSS THE W MTNS AND EASTERN PA SHOULD LIFT BY LATE AM.
CAN/T RULE OUT AN ISOLD SHRA/TSRA ACROSS EASTERN PA ARND MIDDAY
WITH PASSAGE OF COLD FRONT. OTHERWISE...EXPECT A RETURN TO
WIDESPREAD VFR CONDS...AS A GUSTY WEST WIND BRINGS MUCH DRIER AIR
INTO THE REGION BEHIND THE COLD FRONT.

OUTLOOK...

WED-SAT...NO SIG WX EXPECTED.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...STEINBUGL
AVIATION...FITZGERALD/CERU




AREA FORECAST DISCUSSION

NWS STATE COLLEGE PA

 247 AM EDT TUE MAY 19 2015

.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS CENTRAL PENNSYLVANIA TODAY WITH A
MARGINAL/ISOLATED SEVERE WEATHER RISK FROM THE EASTERN COAL REGION
INTO THE POCONOS. A COOLER WEATHER PATTERN WILL GRIP THE REGION
INTO THE WEEKEND BEFORE SUMMER HEAT RETURNS BY MEMORIAL DAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
06Z RADAR SHOWS SCT SHOWERS MAINLY S/E OF I-99 CORRIDOR WITH THE
GREATEST CONCENTRATION /INCLUDING RECENT UPTICK/ OF PCPN ACTIVITY
FOCUSED OVER THE LWR SQV. HRRR FAVORS THIS SCENARIO AND PLACED
HIGHEST POPS FROM THE SOUTH-CENTRAL MTNS NEWD INTO THRU THE SUSQ
VLY. SUBTLE BACKDOOR TYPE FRONT HAS ALLOWED MARINE AIR/EASTERLY
LLVL FLOW TO PENETRATE WWD TO ALONG THE SUSQ RIVER WITH WDSPRD LOW
CIGS AND FOG EXPECTED TO PERSIST THROUGH DAYBREAK. TO THE
WEST...WEAK BUT MOIST UPSLOPE IS PROMOTING LOW CIGS AND FOG ALONG
THE RT 219 CORRIDOR. SITES SUCH AS AOO/UNV WILL LKLY SEE AT LEAST
SOME PATCHY FOG GIVEN LGT WINDS AND MUGGY AIR W/60-65F DEWPTS BUT
MAY ESCAPE THE WORST CONDITIONS.

SHORTWAVE CURRENTLY MOVING THROUGH THE WESTERN GREAT LAKES WILL
TEAM WITH ADDITIONAL ENERGY DROPPING DOWN FROM HUDSON BAY UPPER
TROUGH TO FLATTEN THE ANOMALOUS RIDGE OVER THE NORTHEASTERN U.S.
ONCE THE LOW CLOUDS/FOG ARE ERODED...STRONG PRE-FRONTAL BOUNDARY
LAYER WARMING SHOULD PROVE MORE THAN ADEQUATE FOR CONVECTION WITH
HRRR SHOWING DEVELOPMENT ALONG/EAST OF THE SUSQ VLY BY 18-19Z. SPC
HAS OUTLOOKED EAST-CENTRAL PA FROM THE COAL REGION ENEWD INTO THE
POCONOS WITH MARGINAL SEVERE RISK WITH INCREASING SHEAR TO THE
NORTH. HOWEVER DESPITE WEAKER FLOW ALOFT...CANT RULE OUT THREAT
FOR GUSTY WINDS/SMALL HAIL IN MORE CAPE-DRIVEN STORMS IN STEEP
LLVL LAPSE RATE ENVIRONMENT OVER THE LWR SQV. HEAVY DOWNPOURS
COULD POSE MINOR FLOOD THREAT PROBABLY MORE SO TO URBAN/POOR
DRAINAGE AREAS VS. SMALL STREAMS GIVEN RECENT DRY CONDITIONS AND
BELOW NORMAL STREAM FLOWS FOR THIS TIME OF YEAR.

ANY EARLY EVENING ACTIVITY OVER FAR ERN SXNS SHOULD PUSH OUT OF
THE CWA AFTER 00Z AS NOTICEABLY DRIER AIR SPREADS ACROSS THE AREA
IN THE WAKE OF THE COLD FRONT.

&&

.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
A COOLER BROAD CYCLONIC FLOW WILL BEGIN TO GRIP THE REGION ON
WEDNESDAY WITH DAYTIME HIGHS SOME 15-20F COOLER THAN TODAY. THE
COOLER AIR ALOFT SHOULD PROMOTE AFTN CU DEVELOPMENT WITH A NW
BREEZE ADDING TO THE RELATIVE CHILL. THE MODELS SHOW A SHORTWAVE
TROUGH MOVING QUICKLY FROM THE UPPER GREAT LAKES TOWARD THE MID
ATLANTIC WITH SOME SHOWERS POSSIBLY REACHING THE SW MTNS BY 12Z
THU. THE OTHER CONCERN IS FROST FOR THE NRN MTNS WITH THE FINAL 3
ZONES STARTING THE GROWING SEASON ON 5/21 BUT THE OVERALL PATTERN
DOES NOT LOOK THAT FAVORABLE ATTM SUGGESTING LOW CONFIDENCE.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
A WEAK WAVE EJECTS EASTWARD FROM THE S PLAINS TOWARD THE
CAROLINA/S ON THU...WHILE TROUGH CONTINUES TO SPIN OVER EASTERN
CANADA. CENTRAL PA REMAINS BETWEEN THESE TWO FEATURES...WHICH WILL
KEEP US DRY. EVEN WITH NW FLOW...DAYTIME TEMPS WILL REBOUND A BIT
WARMER EACH DAY. BUT DIURNAL TEMP RANGES WILL BE FAIRLY LARGE
THANKS TO THE DRIER AIRMASS...WHICH WILL BRING CHILLY MORNINGS.
THE COLDEST CONTINUES TO LOOK LIKE THURSDAY MORNING WHERE THERE
REMAINS A RISK FOR PATCHY FROST...MAINLY OVER THE NORTH-CENTRAL
ZONES WHERE GUIDANCE IS SHOWING POSS FOR MID 30S AOA BFD /JUST IN
TIME FOR THE START OF THE GROWING SEASON/.

THE WEAK LOW OVER CAROLINAS/MID ATLANTIC REGION SLIDES OFFSHORE
FRI...WITH SPRAWLING HIGH PRESSURE AREA BUILDING IN FOR SAT/SUN.
ONCE RIDGE AXIS SLIDES BY SAT NIGHT...HUMIDITY WILL BEGIN TO
SLOWLY INCREASE ON SUNDAY WITH RISING TEMPS /AND ISOLATED
LATE DAY CONVECTION POSS/. WARMER AND MUGGIER CONDITIONS ON
MEMORIAL DAY...WITH SCATTERED TO EVEN NUMEROUS SHOWERS/TSTMS IN
THE FORECAST.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AN UNSTABLE AIR MASS AHEAD OF AN APPROACHING COLD FRONT WILL
ALLOW FOR SCATTERED SHRA TO CONTINUE TO MOVE ACROSS CENTRAL PA
OVERNIGHT. ANY OF THESE SHRA COULD PRODUCE BRIEF VIS REDUCTIONS.

HOWEVER...THE MAIN AVIATION CONCERN OVERNIGHT AND THROUGH THE
FIRST HALF OF THE MORNING WILL BE THE DEVELOPING LOW CIGS ACROSS
CENTRAL PA. THE LOW CIGS IN EASTERN PA IS A RESULT OF MARINE AIR
FLOWING OFF THE ATLANTIC OCEAN...COUPLED WITH THE AMPLE LOW LEVEL
MOISTURE PROVIDED BY THE SHOWERS FROM EARLIER.

IFR CIGS ARE ALREADY PRESENT ACROSS MUCH OF EASTERN AND WESTERN
PA AT 06Z...WITH AOO AND UNV THE LONE HOLD OUTS. NEAR TERM MDL
DATA SUPPORT THESE LOW CIGS CONTINUING THROUGH 12Z. THE WESTERN
TAF SITES THAT ARE IFR ARE DUE TO A PLUME OF MOISTURE AHEAD OF
APPROACHING COLD FRONT THAT WILL ASCEND THE W MTNS...LIKELY
RESULTING IN IFR CIGS AT KBFD/KJST OVERNIGHT. BOTH THE SREF AND
LATEST HRRR SUPPORT THIS SCENARIO. MOST FAVORABLE CONDS OVERNIGHT
SHOULD BE AT KAOO/KUNV...WHERE SIG REDUCTIONS APPEAR UNLIKELY.

LOW CIGS ACROSS THE W MTNS AND EASTERN PA SHOULD LIFT BY LATE AM.
CAN/T RULE OUT AN ISOLD SHRA/TSRA ACROSS EASTERN PA ARND MIDDAY
WITH PASSAGE OF COLD FRONT. OTHERWISE...EXPECT A RETURN TO
WIDESPREAD VFR CONDS...AS A GUSTY WEST WIND BRINGS MUCH DRIER AIR
INTO THE REGION BEHIND THE COLD FRONT.

OUTLOOK...

WED-SAT...NO SIG WX EXPECTED.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...RXR
AVIATION...FITZGERALD/CERU



AREA FORECAST DISCUSSION

NWS STATE COLLEGE PA

 150 AM EDT TUE MAY 19 2015

.SYNOPSIS...
A NEARLY STATIONARY...BACK DOOR COLD FRONT WILL BE LOCATED ACROSS
THE SUSQUEHANNA VALLEY TONIGHT. THIS BOUNDARY WILL COMBINE WITH AN
EXTENSIVE PLUME OF DEEP MOISTURE TO FOCUS ADDITIONAL HEAVY
SHOWERS AND THUNDERSTORMS ACROSS CENTRAL PENNSYLVANIA AND THE
SUSQUEHANNA VALLEY OVERNIGHT. A SEPARATE COLD FRONT WILL APPROACH
FROM THE UPPER MIDWEST...PUSHING SOUTHEAST ACROSS THE COMMONWEALTH
TUESDAY AND BRINGING WITH IT...ANOTHER FEW ROUNDS OF SHOWERS AND
THUNDERSTORMS TUESDAY. A COOLER AND DRY AIRMASS WILL MOVE IN
BEHIND THE COLD FRONT FOR THE MIDDLE OF THIS WEEK. SATURDAY AND
SUNDAY SHOULD FEATURE DRY WEATHER WITH PLEASANTLY LOW HUMIDITY
AND NEAR TO SLIGHTLY BELOW NORMAL HIGH TEMPERATURES. WARMER
TEMPERATURES AND MUGGINESS WILL RETURN FOR MEMORIAL DAY.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
VERY HIGH PWAT AIR WILL STAY PARKED OVER THE AREA THROUGH THE
OVERNIGHT. HOWEVER...WITH THE LOSS OF DAYTIME HEATING...
INSTABILITY AND PRECIP RATES IN THE SHRA/TSRA HAVE STEADILY
DIMINISHED.

NEARLY STATIONARY/BACK DOOR CFRONT JUST WEST OF THE SUSQ RIVER
MAINSTEM WILL HELP TO REFIRE AND FOCUS ADDITIONAL LOW-TOPPED
CONVECTION THROUGH THE OVERNIGHT HOURS WITH BASIN AVG RAINFALL
AMOUNTS GENERALLY AROUND ONE QUARTER OF AN INCH. THE FEW LOCATIONS
THAT SEE SLOW MVG OR TRAINING HEAVY SHRA/TSRA WILL PICK UP ANOTHER
0.5 TO 1.0 OF RAIN...PERHAPS LEADING TO SOME ADDITIONAL MINOR
FLOODING NEAR AND TO THE EAST OF A KSEG TO KMDT AND KTHV LINE.

ELSEWHERE...A RATHER MILD/MUGGY NIGHT IS IN STORE WITH ISOLATED TO
SCTD SHRA. LOWS EARLY TUESDAY WILL BE IN THE 60-65F RANGE FROM
NORTH TO SOUTH.

FOG AND LOW CLOUDS ARE AGAIN EXPECTED OVER MOST/ALL OF THE AREA
LATE TONIGHT/EARLY TUESDAY. PERHAPS ONLY THE PLACES WHICH CAN
KEEP WIND OVER 5-6KTS THROUGH THE NIGHT - MAINLY HIGHER ELEVS IN
THE WEST - CAN STAY AWAY FROM BAD VISBYS.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM WEDNESDAY/...
COLD FRONT PUSHES SE ACROSS THE REGION TUESDAY. DEWPOINTS DROP
THROUGH THE DAY IN THE NW HALF OF THE CWA...BUT THE SE WILL STAY
VERY WARM AND HUMID THROUGH MOST OF THE AFTERNOON. PWATS STILL AOA
35 MM NEAR AND SE OF THE I-81 CORRIDOR THROUGH 18Z TUESDAY...AND
THE COMBINATION OF THE HEAT AND MOISTURE WILL HELP TO FIRE UP SFC-
BASED CAPES INTO THE 1500-2000 J/KG RANGE. EXPECT A BKN LINE OR
TWO OF SHOWERS AND PERHAPS A RUMBLE OF THUNDER ALONG THE CFRONT
FROM NEAR KELM...TO KUNV AND KJST DURING THE MIDDAY HOURS. THIS
AREA OF CONVECTION WILL LIKELY INTENSIFY INTO A BKN LINE OF STRONG
TSRA AFTER 16Z TUESDAY NEAR A KAVP TO KSEG AND KHGR LINE.

SPC/S MARGINAL RISK FOR SVR TSRA NIPS A FEW OF OUR EASTERN
COUNTIES TUESDAY...AND COULD SEE THIS BEING EXTENDED A TAD FURTHER
TO THE SW BASED MAINLY ON INSTABILITY AND A LOCALIZED LARGE HAIL
THREAT /COMPARED TO BETTER DEEP LAYER SHEAR FURTHER NORTH/.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
AREA OF SHOWERS/TSTMS WILL BE DEPARTING LATE TUE/EARLY TUE
EVE...ASSOCIATED WITH A COLD FRONT CLEARING THE REGION.

IN IT/S WAKE...RESPECTABLE ANTICYCLONE WILL BUILD IN FROM THE WEST
WITH A PUSH OF NOTICEABLY COOLER AND DRIER AIR FILTERING IN FOR
MIDWEEK. A WEAK WAVE EJECTS EASTWARD FROM THE S PLAINS TOWARD THE
CAROLINA/S ON THU...WHILE TROUGH CONTINUES TO SPIN OVER EASTERN
CANADA. CENTRAL PA REMAINS BETWEEN THESE TWO FEATURES...WHICH WILL
KEEP US DRY. EVEN WITH NW FLOW...DAYTIME TEMPS WILL REBOUND A BIT
WARMER EACH DAY. BUT DIURNAL TEMP RANGES WILL BE FAIRLY LARGE
THANKS TO THE DRIER AIRMASS...WHICH WILL BRING CHILLY MORNINGS.
THE COLDEST CONTINUES TO LOOK LIKE THURSDAY MORNING WHERE THERE
REMAINS A RISK FOR PATCHY FROST...MAINLY OVER THE NORTH-CENTRAL
ZONES WHERE GUIDANCE IS SHOWING POSS FOR MID 30S AOA BFD /JUST IN
TIME FOR THE START OF THE GROWING SEASON/.

THE WEAK LOW OVER CAROLINAS/MID ATLANTIC REGION SLIDES OFFSHORE
FRI...WITH SPRAWLING HIGH PRESSURE AREA BUILDING IN FOR SAT/SUN.
ONCE RIDGE AXIS SLIDES BY SAT NIGHT...HUMIDITY WILL BEGIN TO
SLOWLY INCREASE ON SUNDAY WITH RISING TEMPS /AND ISOLATED
LATE DAY CONVECTION POSS/. WARMER AND MUGGIER CONDITIONS ON
MEMORIAL DAY...WITH SCATTERED TO EVEN NUMEROUS SHOWERS/TSTMS IN
THE FORECAST.

&&

.AVIATION /05Z TUESDAY THROUGH SATURDAY/...

AN UNSTABLE AIR MASS AHEAD OF AN APPROACHING COLD FRONT WILL
ALLOW FOR SCATTERED SHRA TO CONTINUE TO MOVE ACROSS CENTRAL PA
OVERNIGHT. ANY OF THESE SHRA COULD PRODUCE BRIEF VIS REDUCTIONS.

HOWEVER...THE MAIN AVIATION CONCERN OVERNIGHT AND THROUGH THE
FIRST HALF OF THE MORNING WILL BE THE DEVELOPING LOW CIGS ACROSS
CENTRAL PA. THE LOW CIGS IN EASTERN PA IS A RESULT OF MARINE AIR
FLOWING OFF THE ATLANTIC OCEAN...COUPLED WITH THE AMPLE LOW LEVEL
MOISTURE PROVIDED BY THE SHOWERS FROM EARLIER.

IFR CIGS ARE ALREADY PRESENT ACROSS MUCH OF EASTERN AND WESTERN
PA AT 06Z...WITH AOO AND UNV THE LONE HOLD OUTS. NEAR TERM MDL
DATA SUPPORT THESE LOW CIGS CONTINUING THROUGH 12Z. THE WESTERN
TAF SITES THAT ARE IFR ARE DUE TO A PLUME OF MOISTURE AHEAD OF
APPROACHING COLD FRONT THAT WILL ASCEND THE W MTNS...LIKELY
RESULTING IN IFR CIGS AT KBFD/KJST OVERNIGHT. BOTH THE SREF AND
LATEST HRRR SUPPORT THIS SCENARIO. MOST FAVORABLE CONDS OVERNIGHT
SHOULD BE AT KAOO/KUNV...WHERE SIG REDUCTIONS APPEAR UNLIKELY.

LOW CIGS ACROSS THE W MTNS AND EASTERN PA SHOULD LIFT BY LATE AM.
CAN/T RULE OUT AN ISOLD SHRA/TSRA ACROSS EASTERN PA ARND MIDDAY
WITH PASSAGE OF COLD FRONT. OTHERWISE...EXPECT A RETURN TO
WIDESPREAD VFR CONDS...AS A GUSTY WEST WIND BRINGS MUCH DRIER AIR
INTO THE REGION BEHIND THE COLD FRONT.

OUTLOOK...

WED-SAT...NO SIG WX EXPECTED.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...LAMBERT
LONG TERM...RXR
AVIATION...FITZGERALD/CERU




AREA FORECAST DISCUSSION...UPDATED

NWS NASHVILLE TN

 1202 AM CDT TUE MAY 19 2015

.UPDATE...
UPDATED FOR 06Z AVIATION DISCUSSION.

&&

.AVIATION.../06Z TAFS/
GENERALLY VFR CONDITIONS CAN BE EXPECTED OVER THE NEXT 24 HOURS WITH
EXCEPTION OF KCSV WHERE MVFR/IFR VISIBILITIES AND CEILINGS WILL
CONTINUE OFF AND ON THROUGH 16Z WITH THE WORST CONDITIONS EXPECTED
BETWEEN 09Z-14Z.

&&

.PREV DISCUSSION... /ISSUED 844 PM CDT MON MAY 18 2015/

DISCUSSION...
FRONTAL BOUNDARY CURRENTLY STRETCHES FROM CENTRAL IN SOUTHWEST
THROUGH THE MO BOOTHEEL. THIS FEATURE WILL MOVE SOUTHEAST AND
PUSH ACROSS THE MID STATE LATE TONIGHT. FORCING ALONG THIS
BOUNDARY IS EXPECTED TO BE VERY WEAK. IN FACT...NVA LOOKS LIKE IT
WILL DOMINATE AFT 06Z. LATEST HRRR SHOWS A NARROW AND VERY LIGHT
DISORGANIZED BAND OF SHOWER ACTIVITY FOR LATE TONIGHT WHEN THE
FRONT MOVES THROUGH.

WILL GO AHEAD AND LOWER POPS. I WILL KEEP THE CHC CATEGORY GOING
OVER THE FAR SOUTHEAST FOR THE PRE 06Z TIMEFRAME. AFT 06Z...WILL
KEEP A SLIGHT CHANCE OF SHOWERS AND TSTMS GOING AREA WIDE.

OTW...WILL GO AHEAD AND ADD SOME PATCHY FOG ACROSS THE PLATEAU FOR
LATE TONIGHT. MODEL GUIDANCE LEANS TOWARD THE REDUCTION OF VSBYS. ALSO...
DRIER AIR IS NOT EXPECTED TO REACH THE PLAT PRIOR TO 12Z.
REMAINDER OF FCST APPEARS TO BE ON TRACK. COOLER AIR SHOULD REACH
INTO OUR NW COUNTIES BY SUNRISE AS THE FRONT MOVES THROUGH.

PREV DISCUSSION... /ISSUED 309 PM CDT MON MAY 18 2015/

DISCUSSION...

LATEST RADAR IMAGERY SHOWS SCATTERED SHOWERS AND A COUPLE OF
THUNDERSTORMS HAVE DEVELOPED THROUGHOUT THE MID STATE WITH THE
HEAVIEST CONCENTRATION SOUTH OF I-40. EXPECT THIS ACTIVITY TO
CONTINUE SPREADING EASTWARD THROUGH THE AFTERNOON. SHOWERS AND
STORMS WILL DIMINISH THIS EVENING AND TONIGHT AS A COLD FRONT
CURRENTLY IN SE MO AND S IL MOVES ACROSS THE AREA LATE TONIGHT
AND TOMORROW. MOISTURE WILL LINGER OVER SOUTHEASTERN ZONES
ON TUESDAY PRIOR TO FROPA SO COULD STILL SEE SOME ISOLATED SHOWERS
OR STORMS.

SOMEWHAT COOLER AND DRIER WEATHER IS OTHERWISE EXPECTED TUESDAY
INTO WEDNESDAY BEFORE THE NEXT SYSTEM APPROACHES FROM THE PLAINS.
NAM/ECMWF ARE MUCH MORE AGGRESSIVE THAN THE GFS IN BRINGING
NUMEROUS SHOWERS AND STORMS ACROSS THE AREA LATE WEDNESDAY INTO
EARLY THURSDAY. THEIR DEGREE OF MOISTURE RETURN FROM THE GULF MAY
BE TOO AGGRESSIVE...BUT WILL STILL GO AHEAD AND BUMP UP POPS FOR
THIS TIME FRAME. REMAINDER OF THE WEEK LOOKS QUITE NICE WITH LOWS
IN THE 50S AND HIGHS IN THE 70S.

GLOBAL MODELS AGREE THAT MIDDLE TENNESSEE WILL TRANSITION
INTO A WARMER BUT WETTER PATTERN OVER THE MEMORIAL DAY WEEKEND AS
THE PERSISTENT UPPER RIDGE OVER THE SOUTHEAST CONUS SHIFTS MORE
INTO THE ATLANTIC OCEAN...ALLOWING THE ACTIVE SUBTROPICAL JET TO
SHIFT FURTHER TO THE SOUTH OVER OUR REGION. THUS RAIN CHANCES WILL
INCREASE FROM SUNDAY ONWARD WITH HIGHS RETURNING INTO THE 80S AND
LOWS IN THE 60S.

&&

.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

99





AREA FORECAST DISCUSSION

NWS AUSTIN/SAN ANTONIO TX

 357 AM CDT TUE MAY 19 2015

.SHORT TERM (TODAY THROUGH WEDNESDAY)...
A SLOW MOVING MCS OVER WEST CENTRAL TX IS PRODUCING FLASH
FLOODING OVER THE SAN ANGELO AREA EARLY THIS MORNING. IN THE PAST
HOUR OR SO...THE SOUTHERN PORTION OF THE COMPLEX IS TAKING OVER
AND SHOWING A MORE FORWARD PROPAGATING TREND. HI-RES MODEL
SUGGESTED CORFIDI VECTORS SUGGEST THE STORMS TO REMAIN MOSTLY IN
THE FORECAST AREAS TO THE NORTH...BUT AS NOTED IN THE LATEST
SPENES AND FFGMPD DISCUSSIONS...DIFFLUENCE ALOFT IS CAUSING HI-
RES SOLUTIONS TO SLOW DOWN THE MOTION WITH THE SYSTEM EXPECTED
BECOME MORE DISORGANIZED AND SLOWER TOWARD DAYBREAK. UPSHEAR
PROPAGATION VECTORS AND MODEL DEPICTIONS OF AN INCREASING MOISTURE
TAP LATER IN THE MORNING WOULD SUGGEST THAT WE SHOULD CONSIDER AT
LEAST A MENTION OF LOCALLY HEAVY RAINFALL OVER THE NORTHERN HILL
COUNTRY INTO THE NORTHERN PART OF AUSTIN METRO FOR TODAY. SHOULD
THE HRRR CONTINUE TO ADVERTISE ROBUST STORM DEVELOPMENT FURTHER
DOWN THE I-35 CORRIDOR...WE MAY CONSIDER A RAISE OF POPS AND
EXPANSION OF THE HEAVY RAINFALL MENTION. OTHER HI-RES MODELS SHOW
POOR AGREEMENT ON THESE SHORT-TERM TRENDS...SO WITH LOW CONFIDENCE
WILL NOT EXPRESS A CONCERN OVER THE SATURATED SOILS OR THE NEED
FOR A FFA AT THIS TIME.

ASIDE FROM THE ACTIVITY AFFECTING NORTHERN COUNTIES TODAY...OVERALL
MODEL TRENDS HAVE BEEN CONSISTENT FOR A RELATIVELY STABLE FORECAST
FOR OUR SOUTHERN COUNTIES TODAY INTO WEDNESDAY. FORECAST WEAK 700
MB RIDGING SHOULD LEAD TO EVEN LESS CONVECTIVE ACTIVITY FOR
DAYTIME WEDNESDAY THAN TODAY.

&&

.LONG TERM (WEDNESDAY NIGHT THROUGH MONDAY)...
THE RECOVERY TIME FOR SOUTH CENTRAL TX SOILS AND RIVERS IS SHORT
AS MODEL CONSENSUS NOW SHOWS GOOD AGREEMENT ON A COLD FRONT FOCUS
FOR MORE CONVECTION WEDNESDAY NIGHT INTO THURSDAY. THE MORE
DISTINCT INDICATION OF THE FRONT WOULD SUGGEST THAT THE FRONT
COULD POSSIBLY REMOVE SOME OF THE LOW LEVEL MOISTURE AND LEAD TO
LIGHTER RAINFALL TOTALS INITIALLY. SOME BRIEF HEAVY DOWNPOURS AND
A FEW STRONG STORMS COULD OCCUR WEDNESDAY EVENING GIVEN THE
EVENING TIMING EXPECTED.

MODELS SHOW HIGHEST QPF CONCENTRATIONS SHIFTING TO WESTERN
COUNTIES BY LATE THURSDAY WHERE ELEVATED MOISTURE POOLING IS
PINNED AGAINST THE HIGHER TERRAIN TO THE WEST. THE WEAK MID-LEVEL
RIDGING IS CLEARS OUT BY THEN...AND OVERRUNNING OF THE UNSTABLE
MOIST AIR SHOULD BE ABLE TO SPREAD EAST ACROSS ALL AREAS THURSDAY
NIGHT INTO FRIDAY WITH MULTIPLE ROUNDS OF ELEVATED STORMS THAT
TRANSITION INTO DEEPER CONVECTION BY FRIDAY. AT SOME POINT A FLASH
FLOOD WATCH WILL PROBABLY BE ISSUED...POSSIBLY AS EARLY AS
THURSDAY NIGHT. THE HEAVIEST RAINFALL CONCERN IS SAVED FOR
MEMORIAL DAY WEEKEND...AND WITH ALL MODELS SHOWING A GOOD PATTERN
FOR A SLOW MOVING COMPLEX ENHANCED BY A HIGH AMPLITUDE UPPER
TROUGH...WILL SHOW MOST OF THE ATTENTION FOR LATE SATURDAY THROUGH
LATE SUNDAY.

&&

.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY              85  71  86  69  81 /  40  20  20  40  30
AUSTIN BERGSTROM INTL AIRPORT  85  71  85  69  82 /  30  20  20  30  40
NEW BRAUNFELS MUNI AIRPORT     85  71  85  70  82 /  20  20  20  30  40
BURNET MUNI AIRPORT            82  70  84  67  78 /  40  30  20  40  30
DEL RIO INTL AIRPORT           87  72  86  70  83 /  30  20  20  50  40
GEORGETOWN MUNI AIRPORT        84  71  84  67  79 /  40  20  20  40  30
HONDO MUNI AIRPORT             86  71  86  71  83 /  30  20  20  40  40
SAN MARCOS MUNI AIRPORT        85  71  85  70  82 /  30  20  20  30  40
LA GRANGE - FAYETTE REGIONAL   85  73  86  71  83 /  30  20  20  20  40
SAN ANTONIO INTL AIRPORT       85  72  86  71  82 /  30  20  20  30  40
STINSON MUNI AIRPORT           87  73  87  72  84 /  20  20  20  30  40

&&

.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

MESOSCALE/AVIATION...76
SYNOPTIC/GRIDS...18




AREA FORECAST DISCUSSION

NWS BLACKSBURG VA

 217 AM EDT TUE MAY 19 2015

.SYNOPSIS...
A COLD FRONT WILL MOVE EAST ACROSS THE OHIO VALLEY OVERNIGHT...
THEN CROSS THE MID ATLANTIC REGION TUESDAY. SOME ADDITIONAL SHOWERS
ARE POSSIBLE IN THE WEST OVERNIGHT...WITH SHOWERS AND A FEW STORMS
POSSIBLE ON TUESDAY...ESPECIALLY ACROSS THE SOUTHEAST PART OF THE
REGION. ONCE THE FRONT PASSES EAST OF THE AREA TUESDAY...COOLER...DRIER
AIR WILL FILTER INTO THE REGION FOR MID WEEK.

&&

.NEAR TERM /THROUGH TODAY/...
AS OF 935 PM EDT MONDAY...

MUCH OF THE SHOWER AND THUNDERSTORM ACTIVITY HAS ENDED ACROSS THE
REGION. WHAT REMAINS IS MAINLY ACROSS BUCKINGHAM COUNTY VA...BUT
THERE TOO...THE PRECIPITATION WILL CONTINUE TO DISSIPATE. ISOLATED
TO SCATTERED SHOWERS ARE EXPECTED TO RETURN TO WESTERN PARTS OF
THE AREA AFTER MIDNIGHT IN ADVANCE OF AN APPROACHING COLD FRONT.
HAVE MADE MINOR ADJUSTMENTS UPWARD TO THE EXPECTED LOW
TEMPERATURES ACROSS THE EASTERN PORTIONS OF THE AREA. PATCHY FOG
IS EXPECTED TO DEVELOP OVERNIGHT...WITH AREAS THAT RECEIVED RAIN
TODAY...RIVER VALLEYS AND MOUNTAIN VALLEYS THE MOST LIKELY AREAS
TO EXPERIENCE SOME. NO OTHER NOTABLE CHANGES WERE MADE AT THIS
TIME.

AS OF 640 PM EDT MONDAY...

NO MAJOR CHANGES TO THE FORECAST AS WE HEAD INTO THE EVENING
HOURS. WE STILL EXPECT SCATTERED SHOWERS AND SOME STORMS ACROSS
MUCH OF THE REGION. WHAT DID CHANGE WAS THE FOCUS FOR WHERE THE
BEST CHANCES WOULD BE IN THE NEXT COUPLE OF HOURS BASED UPON WHERE
THE GREATEST CONCENTRATION IS CURRENTLY LOCATED...FROM FRANKLIN
COUNTY VA SOUTHWEST TO AROUND PILOT MOUNTAIN IN NORTH
CAROLINA...AND WEST TO THE GRAYSON HIGHLANDS OF SOUTHWEST
VIRGINIA. ALSO...ANOTHER GENEROUS REGION OF PRECIPITATION WAS
MOVING THROUGH ROCKBRIDGE COUNTY VA...AND THERE WAS ANOTHER ONE
APPROACHING WESTERN GREENBRIER COUNTY AND SUMMERS COUNTY IN
SOUTHEAST WEST VIRGINIA. AS WE PROGRESS INTO THE LATE EVENING AND
TOWARDS MIDNIGHT....FORECAST CHANGES WERE A LITTLE MORE EXPANSIVE.
BASED UPON THE LATEST HRRR AND RNK WRF. THE FORECAST WILL NOW
REFLECT LITTLE OR NO COVERAGE OF PRECIPITATION OUTSIDE SOUTHEAST
WEST VIRGINIA AND NEIGHBORING PORTIONS OF SOUTHWEST VIRGINIA ONCE
WE REACH THAT TIME TONIGHT.

AS OF 330 PM EDT MONDAY...

PWATS 2-3 STANDARD DEVIATIONS ABOVE NORMAL WILL HELP FUEL
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS THIS EVENING.
THE AIRMASS IS UNSEASONABLY JUICY BUT LACK OF ANY GOOD DYNAMICS
SHOULD KEEP ACTIVITY UNORGANIZED. NEVER THE LESS...SLOW MOVEMENT
WILL YIELD HEAVY DOWNPOURS FOR ANY PASSING SHOWER/STORM.

FORECAST AREA REMAINS UNDERNEATH A VERY SHARP UPPER LEVEL
RIDGE...WHICH IS PROMOTING VERY LIGHT STEERING WINDS...0-8KM MEAN
WIND OF ONLY 11 KTS...FROM 290 DEGREES. THIS UPPER RIDGE IS
EXPECTED TO WEAKEN AS WE TRANSITION THROUGH THE NEXT 12-18
HOURS...AS LOW PRESSURE MOVES ACROSS THE GREAT LAKES AND INTO
ONTARIO CANADA. AT THE SURFACE...A COLD FRONT WILL TRAIL SOUTH
FROM THE LOW...CROSSING THE OHIO VALLEY TONIGHT. AS THE FRONT
APPROACHES...IT WILL FOCUS THE DEEPER MOISTURE FROM THE OH/TN
VALLEYS INTO THE WEST SIDE OF THE APPALACHIANS. THIS SQUEEZE PLAY
OF DEEPER MOISTURE IN ADDITION TO LINGERING INSTABILITY OVER THE
MOUNTAINS WILL RESULT IN GOOD COVERAGE OF SHOWER ACTIVITY THROUGH
THIS EVENING.

COVERAGE AND INTENSITY OF SHOWER AND THUNDERSTORM ACTIVITY WILL
DECREASE WITH THE LOSS OF DAYTIME HEATING. HOWEVER...WITH THE
COLD FRONT CONTINUING ITS APPROACH OVERNIGHT...SHOWER THREAT WILL
NOT SUBSIDE ALTOGETHER. MOISTURE TRANSPORT AND CONVERGENCE PER
SOUTHWEST WIND FLOW AHEAD OF THE FRONT WILL CONTINUE TO GENERATE
ACTIVITY INTO THE LATE NIGHT.

SURFACE FRONT IS EXPECTED TO REACH THE WESTERN SLOPES OF THE
APPALACHIANS BY DAYBREAK TUESDAY...THEN MOVE OVER AND EAST OF THE
MTNS MID-DAY...CLEARING THE CWA BY TUESDAY EVENING. WILL MAINTAIN
THREAT FOR SHOWERS UNTIL THE PASSAGE OF THE FRONT...FOLLOWED BY
CLEARING AND DRYING WITH FROPA.

MET/MAV TEMPERATURE GUIDANCE LOOKS GOOD...AND USED A BLEND FOR
TONIGHT`S LOWS AND TUESDAYS HIGHS...READINGS REMAINING QUITE MILD
TONIGHT...AOA 60 FOR LOWS...FOLLOWED BY ANOTHER WARM DAY TUESDAY
WITH HIGHS RANGING IN THE 70S MTNS TO THE 80S IN THE LOWER
ELEVATIONS.

ANY SIGNIFICANT COOLING/DRYING WILL NOT TAKE PLACE UNTIL WE CHANGE
AIRMASSES LATER TUESDAY...BECOMING NOTICEABLE ONCE THE SUN GOES
DOWN TUESDAY EVENING.

&&

.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
AS OF 300 PM EDT MONDAY...

ANY LINGERING CONVECTION IN THE FAR SOUTHEAST PORTIONS OF FORECAST
AREA WILL TAPER OFF BY 06Z WEDNESDAY. LOW TEMPERATURES TUESDAY NIGHT
WILL RANGE FROM THE UPPER 40S IN THE NORTHWEST MOUNTAINS TO
THE LOWER 60S IN THE PIEDMONT.

HIGH PRESSURE IN THE MIDWEST WILL RIDGE SOUTHEAST INTO OUR AREA FOR
WEDNESDAY PROVIDING A BREAK FROM THE ACTIVE CONVECTION. THE COOLER
HIGH TEMPERATURES ON WEDNESDAY WILL ALSO BE A WELCOME CHANGE WITH
READINGS FROM THE LOWER 60S IN THE NORTHWEST MOUNTAINS TO THE MID
80S IN THE PIEDMONT. WITH A WEAK SHORTWAVE ROTATING EAST ACROSS THE
REGION WEDNESDAY NIGHT...ALLOW FOR SOME LIGHT POPS IN THE WEST.
LOW TEMPERATURES WEDNESDAY NIGHT WILL VARY FROM THE UPPER 40S IN
THE WEST TO THE UPPER 50S IN THE EAST.

THURSDAYS FORECAST REMAINS A CHALLENGE WITH THE LATEST MODEL RUNS
ALL DEPICT A STRONGER SHORTWAVE TRACKING ACROSS THE AREA...BUT WITH
WIDELY VARYING DEGREES OF INTENSITY AND RESULTANT
MOISTURE/PRECIPITATION. WITH CAUTION...ELECTED TO USE A BLEND OF
SUPERBLEND AND HPCGUIDE WITH SCATTERED POPS FOR THURSDAY. HIGH
TEMPERATURES THURSDAY WILL WARM TO AROUND 60 DEGREES IN THE
NORTHWEST TO AROUND 80 DEGREES ALONG THE SOUTHERN BLUE RIDGE.

SHORTWAVE WILL EXIT TO THE SOUTHEAST THURSDAY NIGHT AS SFC HIGH
PRESSURE SLIDES FROM THE PLAINS TO THE GREAT LAKES. OVERALL...THE
AIRMASS APPEARS TO BE TOO STABLE AND DRY IN THE LOWER LEVELS TO
SUPPORT MUCH THUNDER WITH THIS EVENT. HOWEVER...A NOSE OF
INSTABILITY SUPPORT ISOLATED THUNDERSTORM ACROSS SOUTHERN PORTIONS
OF FORECAST AREA. DIURNAL CONVECTION TAPERS OFF QUICKLY THURSDAY
NIGHT. LOW TEMPERATURES THURSDAY NIGHT WILL GENERALLY VARY FROM THE
UPPER 40S IN THE MOUNTAINS TO THE UPPER 50S IN THE PIEDMONT.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 300 PM EDT MONDAY...

MOISTURE...WARMTH...AND HUMIDITY ARE POISED TO RETURN BY EARLY NEXT
WEEK AS YET ANOTHER DEEP UPPER LOW BUILDS INTO THE SOUTHWEST UNITED
STATE...THE NORTHEAST TROUGH PUSHES EASTWARD INTO THE NORTHERN
ATLANTIC...AND AN ELONGATED RIDGE BETWEEN THESE TWO FEATURES DRIFTS
INTO OUR REGION. HIGH TEMPERATURES FRIDAY WARM INTO THE MID 60S IN
THE MOUNTAINS TO THE MID 70S IN THE PIEDMONT. LOW TEMPERATURES WILL
DROP INTO THE MID 40S TO THE 50S IN GENERAL.

ON SATURDAY...CANADIAN HIGH PRESSURE SHIFTS OFF THE MID-ATLANTIC
COAST...AS FRONTAL BOUNDARY IS CENTRAL U.S. LIFTS NORTHEAST. KEPT
SATURDAY DRY...WITH HIGH TEMPERATURES RANGING FROM THE MID 60S IN
THE NORTHWEST MOUNTAINS TO THE UPPER 70S IN THE PIEDMONT.

AS THE HIGH CENTER MOVES EAST...AN EAST TO SOUTHEAST RETURN FLOW ON
THE BACKSIDE MAY DEVELOP A WEDGE ACROSS THE REGION OVER THE WEEKEND.
WITH THE POTENTIAL OF OVERRUNNING PRECIPITATION DEVELOPING FROM THE
WEST. ADDED A SLIGHT CHANCE OF SHOWERS IN THE NORTHWEST MOUNTAINS OF
NORTH CAROLINA.  MODERATED LOW TEMPERATURES SATURDAY NIGHT WITH
VALUES MAINLY IN THE 50S...WITH INCREASED CLOUD COVER. SCATTERED
SHOWERS CONTINUED ON SUNDAY WITH THE BEST CHANCES IN THE NORTHWEST.

THE UPPER RIDGE WILL SHIFT SOUTHEAST BY MONDAY...ALLOWING AN ACTIVE
BAROCLINIC ZONE TO SHIFT SOUTH AND EAST INTO THE REGION FROM THE
OH/TN VALLEY. CONTINUED THE POTENTIAL FOR SCATTERED CONVECTION ON
TUESDAY.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS OF 200 AM EDT TUESDAY...

OCCASIONAL SHOWER ACTIVITY WILL MOVE ACROSS THE AREA OVERNIGHT AS
WEAK DISTURBANCES PASS OVERHEAD...INTERACTING WITH THE VERY MOIST
AIR IN THE LOW LEVELS OF THE ATMOSPHERE. THROUGH THE REMAINDER
OF THE NIGHT...MID LEVEL CLOUDS WITH BASES AT 8KFT AND UP WILL
REMAIN IN PLACE. WILL ALSO SEE LOCALIZED IFR CONDITIONS AS POCKETS
OF FOG AND ASSOCIATED UPSLOPE LOW CEILINGS DEVELOP...ESPECIALLY
ACROSS AREAS THAT RECEIVED SIGNIFICANT RAINFALL ON MONDAY.
HOWEVER...ANY SHOWERS MOVING ACROSS THE AREA OVERNIGHT MAY STIR
THE ATMOSPHERE JUST ENOUGH TO CAUSE FOG AND LOW CLOUDS TO MIX OUT
FOR A TIME.

FOG AND LOW CEILINGS WILL LIFT AFTER 19/13Z AS HEATING CAUSING
WESTERLY WIND FLOW ALOFT TO MIX DOWN TO THE SURFACE. EXPECT BANDS
OF SHOWER ACTIVITY TO PASS ACROSS THE AREA DURING THE MORNING AND
AFTERNOON...WHICH MAY RESULT IN BRIEF PERIODS OF MVFR/IFR
VISIBILITIES. A COLD FRONT WILL ENTER SOUTHEAST WEST VIRGINIA
DURING THE AFTERNOON...RESULTING IN A SOLID NORTHWEST WIND SHIFT
WITH SPEEDS 6 TO 10 KTS. OCCASIONAL GUSTS UP TO 25 KNOTS ARE
POSSIBLE IN THE MOUNTAINS. FROPA WILL ALSO RESULT IN CLEARING
SKIES AS HIGH PRESSURE BUILDS IN. THE FRONT WILL CONTINUE TO CROSS
THE AREA...EXITING TO THE EAST AROUND 20/00Z.

EXTENDED AVIATION DISCUSSION...

DRIER/COOLER CONDITIONS ARE EXPECTED TUESDAY NIGHT AND WEDNESDAY.
AN UPPER DISTURBANCE WILL LIKELY BRING SOME MVFR CEILINGS AND
SHOWERS BACK INTO THE AREA THURSDAY...MOVING OUT FRIDAY MORNING...
WITH VFR CONDITIONS RETURNING FRIDAY AFTERNOON AND SATURDAY.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...DS/PM
NEAR TERM...DS/PM
SHORT TERM...KK
LONG TERM...KK
AVIATION...AMS/NF




AREA FORECAST DISCUSSION

NWS MOUNT HOLLY NJ

 911 AM EDT TUE MAY 19 2015

.SYNOPSIS...
A COLD FRONT APPROACHING WESTERN PENNSYLVANIA WILL PASS
THROUGH OUR FORECAST AREA THIS EVENING. WEAK HIGH PRESSURE WILL
FOLLOW FOR WEDNESDAY. LOW PRESSURE ALONG THE NORTH CAROLINA COAST
LATE THURSDAY SHOULD MOVE OUT TO SEA BY FRIDAY. ANOTHER COLD FRONT
IS FORECAST TO ARRIVE FROM THE NORTHWEST FRIDAY AFTERNOON WITH
STRONGER HIGH PRESSURE MOVING TO THE MID ATLANTIC COAST THIS
WEEKEND. A WARM FRONT MAY APPROACH FROM THE SOUTHWEST FOR SUNDAY
NIGHT AND MONDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SO THE BACKDOOR FRONT THAT PUSHED SOUTH AND WEST ACROSS THE FORECAST
AREA YESTERDAY IS HANGING OUT ACROSS THE DELMARVA EARLY THIS
MORNING. THIS FRONT IS EXPECTED TO LIFT BACK NORTH ACROSS THE
COASTAL PLAIN DURING THE DAY.

THE COLD FRONT TO OUR WEST ISN`T IN ANY HURRY AND PROBABLY WON`T
MAKE IT OFF THE COAST UNTIL SOME TIME THIS EVENING. THE EARLIER
THINKING WAS THIS AFTERNOON.

THE FOG AND LOW CLOUDS WILL CONTINUE TO LESSEN OR DISSIPATE AS THE
DAYS PROGRESSES, BUT THE ASSUMPTION IS IMPROVEMENT WILL COMMENCE
DOWN SOUTH FIRST AND UP NORTH LAST. IMPROVEMENT SHOULD COINCIDE WITH
THE WARM FRONT AND IT`S MIGRATION TO THE NORTH. THE HRRR SHOWS WINDS
BECOMING WEST ACROSS THE SOUTHERN 1/2 OF THE CWA BY AROUND 15Z, BUT
NOT AROUND 18-19Z ACROSS THE NORTHEAST COASTAL ZONES.

THE ENTIRE AREA SHOULD HAVE ENOUGH TIME TO EXPERIENCE THESE WESTERLY
WINDS, BUT IF THIS DOESN`T MATERIALIZE FOR EVERYONE, FORECAST
TEMPERATURES WILL BE TOO HIGH FOR PLACES LIKE MONMOUTH COUNTY.

THE GFS ISN`T SHOWING DEEP LAYER MOISTURE TODAY AND THE BEST
INSTABILITY AND SYNOPTIC LIFT/FLOW ARE DECOUPLED. THE BEST SURFACE
BASED INSTABILITY SHOULD RESIDE ACROSS THE DELMARVA THIS AFTERNOON
WHILE THE BEST OVERALL LIFT/DYNAMICS/FLOW WILL BE ACROSS THE NORTH.

WITH THAT SAID, WE WILL CONTINUE WITH THE IDEA THAT OVERALL
CONVECTIVE ORGANIZATION WILL BE ON THE LOWER END AS THE DAY WEARS
ON. STILL, WITH SOME DRY AIR ALOFT, WE COULD SEE SOME DECENT GUSTS
IF THIS AFTERNOON`S THUNDERSTORMS DEVELOP ENOUGH TO TAP INTO THAT
LAYER.

AS FOR THE HIGH TEMPERATURES, WE USED MOSTLY AN EVEN BLEND OF THE
GFS/NAM MOS.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/...
AN UPPER-LEVEL TROUGH IS FORECAST TO START SHARPENING UP ACROSS
SOUTHEASTERN CANADA AND INTO THE NORTHEAST LATER TONIGHT. THIS WILL
DRIVE A COLD FRONT OFFSHORE THIS EVENING AND ANY LINGERING
CONVECTION WILL EITHER DISSIPATE OR MOVE OUT TO SEA. AS A RESULT,
KEPT A MENTION IN FOR A TIME IN THE EVENING BUT QUICKLY TAPER THE
POPS DOWN FROM WEST TO EAST. FOLLOWING THE COLD FRONTAL PASSAGE, CAA
BEGINS TO OVERTAKE THE AREA THROUGH THE NIGHT.

THE PRESSURE GRADIENT SHOULD TIGHTEN SOME THROUGH THE NIGHT AS LOW
PRESSURE TRACKS NORTH OF MAINE AND HIGH PRESSURE BUILDS INTO THE
OHIO VALLEY. THIS ALONG WITH SOME CAA SHOULD PROMOTE SOME MIXING
THROUGH THE NIGHT AND THEREFORE AT LEAST SOME WIND AT THE SURFACE.
THE AIRMASS IS DRYING QUITE A BIT THEREFORE OTHER THAN SOME
STRATOCUMULUS ACROSS THE NORTHWEST ZONES, MOST AREAS SHOULD HAVE A
CLEAR OR MOSTLY CLEAR SKY.

AS FOR THE LOW TEMPERATURES, WE USED A NAM/GFS MOS BLEND WITH SOME
TWEAKS.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
500MB: CONFLUENT WESTERLY FLOW OVERHEAD TO START WEDNESDAY WITH
THE NORTHERN BRANCH SLIPPING SOUTHWARD AND BECOMING DOMINANT WITH
ITS SHORT WAVE PASSAGE FRIDAY AND COOLER THAN NORMAL HEIGHTS. A
VERY WARM RIDGE DEVELOPS ALONG THE EAST COAST SUNDAY THROUGH EARLY
NEXT WEEK.

TEMPERATURES: THE FIRST 18 DAYS HAVE AVERAGED AROUND 7 DEGREES
ABOVE NORMAL. CALENDAR DAY AVERAGES WILL BE BELOW NORMAL WEDNESDAY
THROUGH SUNDAY WITH GREATEST NEGATIVE DEPARTURES ALMOST 10 DEGREES
BELOW NORMAL ON SATURDAY. (AND POSSIBLY THURSDAY IF IT RAINS).
CONSIDERABLE WARMING SHOULD BEGIN AROUND MEMORIAL DAY OR
IMMEDIATELY THEREAFTER.

LONG TERM HAZARDS: LOW PROBABILITY POSSIBLE COUNTRYSIDE SPOTTY
TOUCH OF FROST N OF I-78 THURSDAY MORNING OR MAYBE A SLIGHTLY
GREATER CHANCE SATURDAY MORNING?

FORECAST BASIS: UNLESS OTHERWISE NOTED, A 50 50 BLEND 00Z/19 GFS/NAM
MOS GUIDANCE WEDNESDAY - THURSDAY, 00Z/19 MEX MOS THURSDAY NIGHT AND
FRIDAY, THEN THE 0521Z/19 WPC GRIDDED ELEMENTS OF MAX/MIN TEMP, 12
HOUR POP, 6 HOUR DEWPOINT-SKY-WIND FROM FRIDAY NIGHT THROUGH MONDAY.

THE DAILIES...

WEDNESDAY-WEDNESDAY NIGHT...WEAK HIGH PRESSURE IS EXPECTED TO FOLLOW
THE COLD FRONT AND IT SHOULD BRING DRY WEATHER CONDITIONS AND BELOW
NORMAL TEMPERATURES WITH PARTLY CLOUDY SKIES OVERALL (DIURNAL CU WED
AFTERNOON AND THEN SOME HIGH CLOUDINESS IS POSSIBLE LATE WED NIGHT).
WINDS WEDNESDAY NORTHWEST GUSTY 15-20 MPH.  NEARLY CALM AT NIGHT.
TEMPERATURES MAY FALL INTO THE UPPER 30S IN PARTS OF THE POCONOS
REGION AND NORTHWESTERN NEW JERSEY EARLY ON THURSDAY MORNING IF THE
HIGH CLOUD COVER DOES NOT ARRIVE PRIOR TO 09Z/21. IT COULD BE CLOSE
FOR A TOUCH OF LOCALIZED FROST N OF I-78 IN TYPICALLY COLDEST
SPOTS... WALPACK AND PEQUEST NJ AMONG OTHERS? CONFIDENCE: AVERAGE.


THURSDAY...PARTLY CLOUDY OR CONSIDERABLE CLOUDINESS WITH THE APPROACHING
SHORT WAVE AND MODEL DEPENDENT. GENERALLY WEST OR NORTHWEST WIND
GUSTS 15 MPH OR LESS. TEMPERATURES MAY BE FORECAST TOO WARM.
THIS DEPENDENT ON SKYCOVER AND THE NORTHERN EXTENT OF THE RAIN
SHIELD. SINCE THERE IS UNCERTAINTY, THERE IS ALSO BELOW NORMAL
CONFIDENCE IN THE TEMPS AND PROBABILITY OF MEASURABLE RAIN. AT
THIS TIME, THINK THIS THURSDAY FORECAST IS ON THE WARMER SIDE OF
THE ENVELOPE OF SOLUTIONS.

FRIDAY...PARTLY TO MOSTLY SUNNY WITH DIURNAL CU/SC IN THE AFTERNOON. WEST
TO NORTHWEST WIND GUSTY 20 MPH BECOME NEARLY CALM LATE AT NIGHT.
EC HAS -2C AT 850 MB DOWN TO ABOUT I-80. COULD BE A COUNTRYSIDE RISK
OF SPOTTY FROST N OF I-80.

SATURDAY...LOOKS SUNNY! LIGHT WIND.

SUNDAY...INCREASING CLOUDS WITH WARM AIR ADVECTION.  SHOWERS POSSIBLE AT NIGHT?

MONDAY...WARMER WITH A CHANCE OF SHOWERS? UNCERTAINTY FOR MEMORIAL
DAY AND ITS STILL POSSIBLE IT WILL BE RAINFREE. IT DOES APPEAR
THAT WAA SHOWERS SHOULD OCCUR SOMETIME SUNDAY OR MONDAY. PLENTY OF
TIME FOR MORE OPTIMISM IN THE MODEL GUIDANCE.

&&

.AVIATION /13Z TUESDAY THROUGH SATURDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.

TODAY...IFR/LIFR CEILINGS IMPROVING TO MVFR TOWARD LATE MORNING,
THEN VFR DURING THE AFTERNOON AS A COLD FRONT APPROACHES. AFTER
SOME LIFR FOG EARLIER THIS MORNING, MAINLY MVFR FOG WILL IMPROVE
THROUGH THE MORNING. LIGHT EAST TO SOUTHEAST WINDS, TURNING
TOWARDS THE SOUTH AND SOUTHWEST AROUND 10 KNOTS IN THE AFTERNOON.
SOME SHOWERS AND THUNDERSTORMS /AFTERNOON/ ARE EXPECTED TO OCCUR
AHEAD OF THE COLD FRONT, HOWEVER THESE MAY BE MAINLY SCATTERED.
LOWER CONFIDENCE ON THE TIMING OF IMPROVEMENT TO MVFR/VFR, AND
ALSO SHOWER/THUNDER COVERAGE ESPECIALLY THIS AFTERNOON.

TONIGHT...A FEW SHOWERS OR A THUNDERSTORM EARLY, OTHERWISE VFR. WEST
TO NORTHWEST WINDS MOSTLY 5-15 KNOTS.

OUTLOOK...
WEDNESDAY...VFR.  SCT-BKN AOA 5000 FT. NORTHWEST GUSTY 15 TO 20 KT
DURING THE DAY BECOME NEARLY CALM AT NIGHT.

THURSDAY...VFR.  SCT-BKN AOA 5000 FT.   GENERALLY WEST WIND GUST
UNDER 15 KT. SMALL CHC OF SHOWERS PHL SEWD, ESPECIALLY S DE AND
COASTAL SE NJ.

FRIDAY...VFR SCT-BKN AOA 5000 FT MAY BECOME COMPLETELY CLEAR NIGHT.
WEST-NORTHWEST WIND GUSTY 20 KT SHOULD DIMINISH AT NIGHT.

SATURDAY...VFR NEARLY CLEAR.  LIGHT WIND.

&&

.MARINE...
A LIGHT ONSHORE FLOW TO START TODAY WILL VEER TO SOUTH THEN TO
SOUTHWEST AND WEST BY LATE AFTERNOON. A COLD FRONT WILL MOVE THROUGH
THIS EVENING WITH CAA DEVELOPING IN ITS WAKE. THE CONDITIONS ARE
EXPECTED TO BE BELOW SMALL CRAFT ADVISORY CRITERIA TODAY INTO
TONIGHT, HOWEVER THE CAA LATE TONIGHT AND MAINLY TOWARD DAYBREAK
WEDNESDAY MAY ALLOW FOR WIND GUSTS TO NEAR 25 KNOTS. THIS LOOKS
SHORT IN DURATION THOUGH IF IT WERE TO OCCUR. SOME SHOWERS AND
THUNDERSTORMS ARE EXPECTED TODAY INTO TONIGHT AHEAD OF THE COLD
FRONT.

OUTLOOK...
WEDNESDAY...NO SCA HEADLINE ANTICIPATED AT THIS TIME. NW WIND GUSTS
AROUND 20 KT DURING THE DAY DIMINISH AT NIGHT WITH STRONGEST
DAYTIME WIND PROBABLY ALONG THE NEARSHORE WATERS.

THURSDAY....SCA NOT ANTICIPATED AT THIS TIME, THOUGHT KEEPING AN
EYE ON THE NORTH CAROLINA SFC LOW.

FRIDAY....SMALL CHANCE OF SCA FOR NEARSHORE WEST TO NORTHWEST WIND
GUSTS NEAR 25 KT DURING THE DAY DIMINISHING AT NIGHT.

SATURDAY...NO MARINE HEADLINE ANTICIPATED.

&&

.FIRE WEATHER...
WIND GUSTS SHOULD BE AROUND 20 MPH FROM THE NORTHWEST ON WEDNESDAY
AFTERNOON. RELATIVE HUMIDITY VALUES MAY FALL TO NEAR 30 PERCENT
ESPECIALLY IN PARTS OF EASTERN PENNSYLVANIA AND NEW JERSEY.

FRIDAY AFTERNOON MAY BE SIMILAR TO WEDNESDAY AFTERNOON.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...DRAG/KRUZDLO
NEAR TERM...GORSE/KRUZDLO
SHORT TERM...GORSE
LONG TERM...DRAG
AVIATION...DRAG/GORSE/KRUZDLO
MARINE...DRAG/GORSE
FIRE WEATHER...DRAG



AREA FORECAST DISCUSSION

NWS LINCOLN IL

 1037 AM CDT TUE MAY 19 2015

.UPDATE...
ISSUED AT 1037 AM CDT TUE MAY 19 2015

SURFACE HIGH PRESSURE CENTERED OVER THE NORTHERN PLAINS WILL
CONTINUE TO SHIFT EASTWARD TODAY BRINGING LIGHT NORTHERLY WINDS
AND CONTINUED ADVECTION OF COOL AND RELATIVELY DRY AIR INTO
CENTRAL IL. GENERAL SUBSIDENCE ALOFT IS INDICATED BY MODEL
FORECASTS AND CURRENT WATER VAPOR IMAGERY, HOWEVER A BAND OF LOW
CLOUD OVER PORTIONS OF IL MAINLY NORTH OF I-72 PERSISTS THIS
MORNING. MODEL TIME-HEIGHT PLOTS NOW INDICATE THIS LAYER FAIRLY
WELL AND HRRR HALTS THE PROGRESS OF THE BAND AROUND THE CURRENT
LOCATION. SURFACE HEATING WILL TEND TO RAISE THE CEILING HEIGHT
THROUGH THE AFTERNOON...BUT ENOUGH MOISTURE SHOULD PERSIST THAT
THE LAYER SHOULD TRANSITION INTO A SCATTERED SHALLOW CUMULUS LAYER
AROUND 4000-5000 FEET. FORECAST IS MORE OR LESS ON TRACK, BUT HAVE
MADE SOME MODIFICATIONS TO CLOUD COVER THROUGH THE AFTERNOON TO
BETTER DEPICT THE SITUATION.

&&

.SHORT TERM...(TODAY)
ISSUED AT 331 AM CDT TUE MAY 19 2015

CANADIAN HIGH PRESSURE WILL BEGIN TO BUILD INTO CENTRAL AND
SOUTHEAST ILLINOIS TODAY, ACCOMPANIED BY A CONTINUED FEED OF
COOLER/DRIER AIR IN THE WAKE OF YESTERDAY`S COLD FRONT. THIS
SCENARIO SUPPORTS A DRY DAY, WITH AFTERNOON HIGH TEMPERATURES
MAINLY IN THE 60S.

ONE FLY IN THE OINTMENT, ONE THAT MAY IMPACT TEMPERATURES ACROSS
NORTHERN PORTIONS OF THE FORECAST AREA, IS A LARGE AREA OF WRAP-
AROUND CLOUDINESS THAT HAS STARTED TO SINK INTO FAR NORTHERN
PORTIONS OVER THE FORECAST AREA OVER THE PAST FEW HOURS. NONE OF THE
MODEL GUIDANCE HAS A VERY GOOD HANDLE ON THE CURRENT SOUTHERN EXTENT
OF THE CLOUD SHIELD, OR IN MANY CASES EVEN INDICATES IT AT ALL. AT
THIS POINT, HAVE USED SIMPLE EXTRAPOLATION OF THE CURRENT CLOUD
SHIELD INTO MID-MORNING. THEN, AS DIURNAL MIXING GETS GOING, HAVE
ALLOWED THE SOUTHERN EDGE OF THE CLOUD SHIELD TO MIX-OUT/ERODE AND
BE NORTH OF THE AREA BY MIDDAY. SO, BASICALLY, MUCH OF THE FORECAST
AREA ALONG/NORTH OF I-74 WILL BE CLOUDY TO START THE DAY, GRADUALLY
BECOMING MOSTLY SUNNY BY AFTERNOON.

.LONG TERM...(TONIGHT THROUGH MONDAY)
ISSUED AT 331 AM CDT TUE MAY 19 2015

CANADIAN HIGH PRESSURE WILL BE SPRAWLED NORTH OF IL ACROSS WI
TONIGHT KEEPING CENTRAL IL DRY. MID/HIGH CLOUDS TO INCREASE FROM THE
WEST DURING TONIGHT AHEAD OF NEXT WEATHER SYSTEM EJECTING INTO THE
CENTRAL PLAINS. LOWS TONIGHT IN THE MID TO UPPER 40S WITH COOLEST
READINGS OVER EAST CENTRAL IL WHERE CLOUDS MOVE IN LATER.

SHORT WAVE TO WEAKEN AS IT EJECTS INTO CENTRAL IL WED AFTERNOON AND
LIKELY SPREADING LIGHT RAIN SHOWERS EAST ACROSS CENTRAL AND SE IL
DURING THE DAY WED. SPC KEEPS CHANCES OF THUNDER SOUTH OF I-64 OVER
SOUTHERN IL ON WED BUT KEPT SLIGHT CHANCE OF THUNDER WED AFTERNOON
OVER SW CWA. NE FLOW AROUND HIGH PRESSURE OVER THE GREAT LAKES WILL
TRY TO BRING DRIER AIR INTO NE CWA WHERE RAINFALL AMOUNTS ONLY ONE
TO TWO TENTHS WHILE A QUARTER TO A THIRD OF AN INCH OF RAIN SW CWA.
BEST RAIN CHANCES SHIFT INTO SE IL WED EVENING WHILE THE IL RIVER
VALLEY DRIER OUT AS WEAKENING SYSTEM GETS SHUNTED TO THE SE AS
ANOTHER HIGH PRESSURE SYSTEM NOSES INTO IL FROM THE CENTRAL PLAINS.
WENT A FEW DEGREES COOLER THAN MET/MAV GUIDANCE FOR HIGHS WED
ESPECIALLY CENTRAL AND WESTERN AREAS WHERE HIGHER CHANCES OF
RAIN WITH MID TO UPPER 50S NORTH AND LOWER 60S IN SOUTHEAST IL.

HIGH PRESSURE SETTLES INTO MO THU AFTERNOON INTO THU NIGHT AND TO
BRING DRY WEATHER TO IL WITH RETURN OF PARTLY TO MOSTLY SUNNY SKIES
BY THU AFTERNOON. MILDER HIGHS IN THE MID TO UPPER 60S BUT STILL
BELOW NORMAL HIGHS IN THE MID 70S. LOWS THU NIGHT IN THE MID TO
UPPER 40S. A NICE DAY IN STORE FRIDAY AS HIGH PRESSURE SETTLES OVER
IL WITH AMPLE SUNSHINE...FAIRLY LIGHT WINDS AND HIGHS IN THE LOWER
70S. DRY CONDITIONS CONTINUE FRIDAY NIGHT ACROSS IL WITH LOWS IN THE
LOW TO MID 50S.

MOST OF CENTRAL AND ESPECIALLY EASTERN IL APPEAR TO STAY DRY YET ON
SATURDAY WITH INCREASING CLOUDS AND HIGHS IN THE MID 70S AS HIGH
PRESSURE SLIPS OFF THE MID ATLANTIC COAST BY SUNSET SATURDAY AND
UPPER LEVEL RIDGE INTO IL. HAVE SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS SAT AFTERNOON OVER WEST CENTRAL IL WHILE BETTER
CHANCES OF SHOWERS AND THUNDERSTORMS TO SPREAD NE ACROSS CENTRAL IL
DURING SAT NIGHT AND SUNDAY WITH SHORT WAVES EJECTING NE FROM THE
LARGE UPPER LEVEL TROF OVER THE ROCKIES. INCREASING GULF MOISTURE
WITH SOUTHERLY FLOW TO PROVIDE GOOD CHANCES OF SHOWERS AND
THUNDERSTORMS SUNDAY INTO MONDAY AND TO EVEN LINGER INTO NEXT
TUESDAY. A WARMER AND MORE HUMID STRETCH OF WEATHER FROM SUNDAY
THROUGH TUESDAY WITH HIGHS IN THE UPPER 70S (LOWER 80S IN SOUTHEAST
IL) AND DEWPOINTS IN THE 60S.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 650 AM CDT TUE MAY 19 2015

LARGE AREA OF MVFR CLOUDS HAS CONTINUED TO SINK SOUTHWARD ACROSS
CENTRAL ILLINOIS OVERNIGHT. KPIA & KBMI HAVE BEEN BENEATH THE
CLOUDS FOR A WHILE, BUT IT NOW LOOKS AS THOUGH ALL LOCAL TERMINALS
WILL BE IMPACTED. NONE OF THE MODEL GUIDANCE HAS HAD A GOOD FEEL
ON THESE CLOUDS AT ALL, AND INITIAL FORECAST IS BASED PARTLY ON
SATELLITE EXTRAPOLATION AND PARTLY ON DIURNAL EFFECTS THAT SHOULD
TEND TO ERODE THE SOUTHERN EDGE OF THE CLOUD FIELD. SO, HAVE SKIES
SCATTERING OUT AGAIN THIS AFTERNOON, WITH VFR CONDTIONS THEN
PERSISTING THROUGH THE REST OF THE PERIOD. HOWEVER, CONFIDENCE IN
THE EXACT TIME OF THE CLEARING IS NOT HIGH. NORTHWEST WINDS WILL
CONTINUE TO DIMINISH AS HIGH PRESSURE BUILDS INTO THE AREA,
BECOMING VARIABLE BY TONIGHT.


&&

.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE...ONTON
SHORT TERM...BAK
LONG TERM...07
AVIATION...BAK




AREA FORECAST DISCUSSION

NWS GRAY ME

 954 AM EDT TUE MAY 19 2015

.SYNOPSIS...
SHOWERS ASSOCIATED WITH A WARM FRONT WILL SPREAD ACROSS THE REGION
THIS MORNING. SHOWERS AND THUNDERSTORMS WILL DEVELOP THIS
AFTERNOON AND EVENING AHEAD OF A COLD FRONT. A NORTHWEST FLOW
WILL DEVELOP BEHIND THE FRONT TONIGHT AND PROVIDE COOL BUT MOSTLY
QUIET WEATHER INTO THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
950 AM UPDATE...HAVE UPDATED THE FORECAST TO FRESHEN UP THE TIMING
OF POPS TODAY AS WELL AS TEMPERATURES. OVERALL...FORECAST REMAINS
ON TRACK. WIDESPREAD RAIN THIS MORNING WILL PUSH OFF THE COAST IN
A FEW HOURS AND SHOULD ALLOW FOR AT LEAST PARTIAL SUNSHINE THIS
AFTERNOON...ESPECIALLY ACROSS THE INTERIOR. THIS WILL LEAD TO
INCREASING INSTABILITY. AS A SHORT WAVE TROUGH APPROACHES THIS
AFTERNOON...THUNDERSTORMS SHOULD DEVELOP IN UPSTATE NY AND VT AND
REACH THE CT VALLEY BY 4 PM. THE STORMS SHOULD THEN PROGRESS
EASTWARD AND EXIT THE COAST BETWEEN 8 AND 9 PM. A FEW SEVERE
STORMS WILL BE POSSIBLE...ESPECIALLY ACROSS NH.

PREVIOUSLY...

530AM UPDATE...
HAVE UPDATED HOURLY PRECIPITATION CHANCES BASED ON RECENT RADAR
TRENDS. MUCH OF THE AREA IS SEEING SHOWERS NOW EXCEPT THE
IMMEDIATE COAST. THIS WILL CHANGE SOON. BACK EDGE OF PRECIPITATION
MOVING INTO VERMONT NOW AND WILL REACH WESTERN NEW HAMPSHIRE
WITHIN THE NEXT 2 TO 3 HOURS.

ORIGINAL DISCUSSION...
AREA OF SHOWERS AND A FEW EMBEDDED THUNDERSTORMS IS MOVING THROUGH
THE HUDSON VALLEY EARLY THIS MORNING AND SHOULD ARRIVE IN NEW
HAMPSHIRE IN THE NEXT TWO HOURS BEFORE SPREADING EASTWARD ACROSS
THE REST OF NEW HAMPSHIRE AND WESTERN MAINE THIS MORNING. THIS
AREA OF PRECIPITATION IS ASSOCIATED WITH A WARM FRONT-LIKE
FEATURE IN THAT BEHIND IT DEWPOINTS ARE SURGING INTO THE MID 60S
WHILE THE COOL MARITIME AIR MASS AHEAD OF IT IS COOLER AND WITH
LOWER DEWPOINTS. BUT YOU WILL BE HARD PRESSED TO FIND A
NOTICEABLE WIND SHIFT OR PRESSURE TROUGH WITH IT. SUCH IS LIFE IN
NORTHERN NEW ENGLAND.

AREA OF RAIN WILL MOVE INTO THE MIDCOAST REGION OF MAINE LATE IN
THE MORNING AND PERSIST INTO THE AFTERNOON. WHILE NEW HAMPSHIRE
WILL SEE THE RAIN ENDING EARLIER IN THE MORNING. BREAKS IN THE
CLOUDS SHOULD ALLOW FOR PRETTY GOOD WARMING INTO THE MID TO UPPER
70S OVER WESTERN NEW HAMPSHIRE. THE COMBINATION OF THIS WARMING...
THE INCREASING LOW LEVEL MOISTURE... AND COOLING TEMPERATURES
ALOFT ASSOCIATED WITH A SHORTWAVE TROUGH WILL PROVIDE SUBSTANTIAL
INSTABILITY THIS AFTERNOON... PERHAPS THE BEST SEEN YET THIS
SEASON. CAPE APPROACHES OR EXCEEDS 1000 BY LATE THIS AFTERNOON AND
EARLY EVENING OVER VERMONT AND NEW HAMPSHIRE. JUST AS INSTABILITY
IS INCREASING... A COLD FRONT WILL BEGIN MOVING ACROSS NORTHERN
NEW ENGLAND FROM WEST TO EAST. THIS WILL PROVIDE LOW LEVEL
CONVERGENCE TO ADD LIFT TO THE EQUATION... AIDING IN THE
DEVELOPMENT OF THUNDERSTORMS. BEST INSTABILITY AND LIFT DOES NOT
ARRIVE UNTIL LATE IN THE DAY... SO THUNDERSTORM POTENTIAL SEEMS TO
BE MORE IN THE 4PM-8PM TIME PERIOD... WITH REMNANT STORMS LIKELY
MAINTAINING THEMSELVES THROUGH ELEVATED INSTABILITY THROUGH
MIDNIGHT TONIGHT.

MESOSCALE MODELS INCLUDING THE NAM AND HRRR INDICATING POTENTIALLY
TWO SEPARATE AREAS OF MORE WIDESPREAD THUNDERSTORM ACTIVITY LATE
THIS AFTERNOON. THE FIRST IS OVER THE NORTHERN ADIRONDACKS AND THE
SECOND OVER THE CATSKILLS... BOTH AREAS FIRING AS THE FRONT MOVES
THROUGH TO PROVIDE LIFT AND MAY BE ENHANCED DUE TO TERRAIN-BASED
INSTABILITY. IF THIS SCENARIO UNFOLDS... THEN THE NORTHERN AREA OF
THUNDERSTORMS WOULD MOVE EAST ACROSS VERMONT AND THE NORTHERN HALF
OF NEW HAMPSHIRE AND INTO NORTHWEST MAINE IN THE EVENING. THE
SOUTHERN CLUSTER WOULD MOVE EAST MAINLY INTO MASSACHUSETTS. HAVE
ORIENTED AFTERNOON/EVENING THUNDERSTORM CHANCES AS BEING GREATEST
IN THE NORTH WHERE THE MORE NORTHERN CLUSTER OF STORMS WOULD MOVE
ACROSS BUT HAVE MAINTAINED AT LEAST A CHANCE OF THUNDERSTORMS OVER
ALL OF NEW HAMPSHIRE AND EXTENDING INTO FAR WESTERN/NORTHERN
MAINE IN THE EVENING.

ONE FINAL INGREDIENT TO ADD TO THE MIX TODAY IS INCREASING WIND
SHEAR. BY EVENING... AROUND THE TIME THE FRONT WILL BE MOVING INTO
NEW HAMPSHIRE... WINDS ALOFT APPROACH 50 KT AT 700 MB WHILE
SURFACE WINDS ARE BROADLY LIGHT OUT OF THE SOUTH. THIS WILL
PROVIDE ENOUGH SPEED SHEAR TO PROVIDE STORM ORGANIZATION AND
SUPERCELL TYPE STRUCTURES. THIS MAKES SEVERE THUNDERSTORMS MORE
LIKELY... WITH DAMAGING WINDS AND HAIL BEING THE PRIMARY THREATS.
HOWEVER... GIVEN LOW LEVEL WINDS OUT OF THE SOUTH... CANNOT RULE
OUT THE POSSIBILITY OF AN ISOLATED TORNADO PARTICULARLY IN AREAS
WHERE LOW LEVEL WINDS ARE CHANNELED BY TERRAIN AND PRODUCE GREATER
LOCALIZED DIRECTIONAL SHEAR. HAVE MENTIONED THE THREAT OF DAMAGING
WINDS AND LARGE HAIL IN THE PUBLIC FORECAST FOR LATE THIS
AFTERNOON. HAVE ALSO ORIENTED HOURLY PRECIPITATION CHANCES TO
BETTER REFLECT THE IDEA THAT EARLY MORNING SHOWERS WILL MOVE EAST
BEFORE THE CHANCE OF THUNDERSTORMS ARRIVES LATE.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
COLD FRONT WILL PUSH EAST ACROSS THE REGION TONIGHT WITH
THUNDERSTORM ACTIVITY LIKELY LINGERING INTO THE EVENING...
POSSIBLY TO AROUND MIDNIGHT IN NORTHERN MAINE. COOLER AND DRIER
AIR WILL BE MOVING IN BEHIND THE COLD FRONT. COULD SEE SOME FOG
NEAR THE COAST BEFORE THE FRONT MOVES THROUGH AND BEGINS TO
MIX/DRY THINGS OUT. TEMPERATURES FALL INTO THE UPPER 40S AND LOW
50S.

WILL BE A COOLER DAY ON WEDNESDAY FOR MOST OF THE REGION. BUT ON
THE COAST IT MAY ACTUALLY BE A FEW DEGREES WARMER... A TYPICAL
RESULT OF A PASSING COLD FRONT AND A SHIFT TO OFFSHORE WINDS. HIGH
TEMPERATURES RANGE FROM THE MID 50S IN THE NORTH TO THE MID 60S
NEAR THE COAST. DEWPOINTS WILL BE FALLING INTO THE 30S WHICH WILL
MAKE IT DIFFICULT FOR ANY SHOWERS TO DEVELOP IN SPITE OF SOME LIFT
MOVING THROUGH WITH THE PASSING OF THE UPPER LEVEL TROUGH.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
A LARGE UPPER LEVEL TROUGH WILL DOMINATE THE FLOW ACROSS NEW
ENGLAND THROUGH THE WEEKEND. SEVERAL DISTURBANCES WILL ROTATE
AROUND THE TROUGH, HOWEVER, COOL DRY WEATHER WILL RULE FOR MUCH OF
THE PERIOD. A MOISTURE-STARVED FRONT DROPPING SOUTHWARD FROM
CANADA COULD BRING A FEW SHOWERS TO THE REGION FRIDAY. BEHIND THE
FRONT...TEMPERATURES WILL BE MAINLY IN THE 60S SATURDAY BUT SHOULD
START TO WARM INTO THE 70S MOST AREAS FOR SUNDAY AND MONDAY AS THE
TROUGH AXIS SLIDES EAST OF THE REGION. MODELS NOW DELAY NEXT
SIGNIFICANT PRECIPITATION UNTIL TUESDAY, ALLOWING FOR A VERY
PLEASANT HOLIDAY WEEKEND.

NOTE: THE FREEZE/FROST PROGRAM STARTS IN NORTHERN ZONES
THURSDAY MAY 21. LOW TEMPERATURES THURSDAY AND SATURDAY MORNINGS
WILL DROP NEAR OR BELOW FREEZING ACROSS NORTHERN ZONES AND MAY
REQUIRE FREEZE WARNINGS AND/OR FROST ADVISORIES.

&&

.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
SHORT TERM...EARLY MORNING IFR/LIFR CONDITIONS WILL BEGIN
IMPROVING THIS MORNING EVEN AS AN AREA OF RAIN MOVES ACROSS THE
AREA. COULD SEE MVFR CEILINGS LINGER THROUGH MUCH OF THE DAY BUT
THERE IS A BETTER CHANCE THAT CONDITIONS WILL BREAK OUT TO VFR FOR
AT LEAST A FEW HOURS. THERE IS A CHANCE OF THUNDERSTORMS ACROSS
MUCH OF NEW HAMPSHIRE LATE THIS AFTERNOON INTO EARLY THIS EVENING.
LOW CLOUDS MAY MAKE A RETURN VISIT TO COASTAL MAINE EARLY THIS
EVENING BUT THE PASSING OF A COLD FRONT DURING THE NIGHT WILL
LIKELY IMPROVE CONDITIONS TO VFR EVENTUALLY.

LONG TERM...MAINLY VFR CONDITIONS EXPECTED.

&&

.MARINE...
SHORT TERM...SOUTHERLY FLOW INCREASES TODAY THEN SHIFTS TO THE
WEST TONIGHT BEHIND A COLD FRONT. WEST WINDS COULD GUST TO AROUND
20 KT ON WEDNESDAY.

LONG TERM...WITH MAINLY OFFSHORE FLOW...WINDS AND SEAS EXPECTED
TO REMAIN BELOW SCA CRITERIA. STRONGEST WINDS AND HIGHEST SEAS
SHOULD BE WELL OFFSHORE.

&&

.FIRE WEATHER...
MOIST AIR AND WIDESPREAD WETTING RAIN TODAY WILL KEEP FIRE DANGER
CONDITIONS LOW. DRY AIR MOVES IN BEHIND A COLD FRONT TONIGHT...
LEADING TO MUCH DRIER CONDITIONS WEDNESDAY INTO THE WEEKEND.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.

&&

$$

NEAR TERM UPDATE...EKSTER



AREA FORECAST DISCUSSION

NWS MARQUETTE MI

 734 AM EDT TUE MAY 19 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 506 AM EDT TUE MAY 19 2015

LATEST WV IMAGERY AND RAP ANALYSIS INDICATED A MID/UPPER LEVEL
TROUGH FROM NE CANADA EXTENDING INTO THE UPPER GREAT LAKES WITH THE
WEAKENING REMANTS OF THE MID-LVL LOW CIRCULATION CENTER SW OF JAMES
BAY. AT THE SFC...A TROUGH EXTENDED ACROSS THE UPPER GREAT LAKES
FROM LOW PRES NOW OVER QUEBEC. WRAPAROUND MOISTURE FROM THE LOW
CIRCULATION STILL SUSTAINING SNOW SHOWERS MIXED WITH RAIN SHOWERS
ACROSS PORTIONS OF NRN UPPER MI EARLY THIS MORNING AS NOTED ON THE
MQT RADAR.

TODAY...SFC HIGH PRES WILL BUILD TOWARD THE AREA DURING THE DAY AS
LOW-LEVEL FLOW BECOMES INCREASINGLY ANTICYCLONIC. THE ASSOCIATED
DRYING AS THE DEEPER MOISTURE DEPARTS TO THE EAST WILL ALLOW ANY
LINGERING SNOW SHOWERS TO GRADUALLY DIMINISH THIS MORNING FROM WEST
TO EAST AND END OVER MOST OF THE CWA BY 18Z. ONLY A DUSTING TO MAYBE
HALF AN INCH OF SNOW ACCUMULATION IS POSSIBLE ON GRASSY AREAS OF
NORTH CENTRAL HIGHER TERRAIN LOCATIONS BEFORE SNOW ENDS THIS
MORNING. CLOUDS WILL SLOWLY DISSIPATE FROM WEST TO EAST MAINLY
DURING THE MID TO LATE AFTERNOON WITH HIGHER PRESSURE AND ASSOC
DRIER AIR WORKING IN FM WEST. OTHERWISE...UNSEASONABLY COLD
CONDITIONS ARE EXPECTED UNDER GUSTY NW WINDS (20 TO 25 MPH
ESPECIALLY EAST HALF) AS HIGHS WILL RANGE FROM UPPER 30S/LOWER 40S
NORTH AND EAST TO THE MID AND UPPER 40S SOUTH AND WEST.

TONIGHT...HIGH PRESSURE BUILDS INTO THE AREA TONIGHT. THE DRY AIR
ASSOCIATED WITH THE HIGH WILL DIMINISH ANY LINGERING CLOUDS OVER THE
EASTERN CWA QUICKLY DURING THE EARLY EVENING HOURS. THE CLEARING
SKIES AND WEAKENING WINDS WILL LEAD TO A COLD NIGHT ACROSS THE AREA.
HAVE FOLLOWED THE LOWER END OF MODEL GUIDANCE (GIVEN PWAT VALUES AT
OR BELOW 0.25IN ACROSS MUCH OF THE INTERIOR)...WHICH INDICATES
VALUES IN THE 20S FOR MOST INTERIOR LOCATIONS...COLDEST INTERIOR
WEST ALONG THE WI BORDER WHERE LOWS COULD DIP INTO THE LOWER TO MID
20S. ALTHOUGH OUR FROST/FREEZE PROGRAM HASN/T STARTED YET...WOULD
EXPECT A WIDESPREAD FROST ACROSS UPPER MICHIGAN AND A HARD FREEZE
OVER THE INTERIOR WEST. PERSONS WITH SENSITIVE PLANTS SHOULD TAKE
THE NECESSARY PRECAUTIONS TO PROTECT AGAINST A HARD FROST AND/OR
FREEZE AND WILL INCLUDE A MENTION OF THIS IN THE HWO STATEMENT.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 238 AM EDT TUE MAY 19 2015

FROM WEDNESDAY THROUGH THE END OF THE WORK WEEK...A 500MB TROUGH
WILL REMAIN ACROSS THE GREAT LAKES REGION. THE LOW ITSELF WILL GET
AS CLOSE AS JAMES BAY THURSDAY AFTERNOON. AT THE SFC MUCH OF THIS
TIME PERIOD WILL BE MARKED BY A RIDGE OF HIGH PRESSURE EXTENDING
EITHER S CENTRAL CANADA OR THE NORTHERN TO CENTRAL PLAINS. LOOK FOR
THE RIDGE TO BE SUPPRESSED WEDNESDAY AFTERNOON INTO THURSDAY. A W-E
ORIENTED COLD FRONT SET UP JUST N OF LAKE SUPERIOR ACROSS ONTARIO
WILL SINK ACROSS LAKE SUPERIOR WEDNESDAY AFTERNOON...AND UPPER MI
WEDNESDAY NIGHT BEFORE PUSHING ACROSS WI AND LOWER MI DURING THE DAY
THURSDAY.

WEDNESDAY WILL BE DRY...AND EVEN WITH GOOD MIXING WINDS SHOULD STAY
FAIRLY LIGHT AS YOU NEED TO GO ABOVE 500MB TO GET ANYTHING ABOVE
15KTS. THE COLD FRONT SINKING THROUGH WILL BRING SOME MOISTURE TO
THE AREA...BUT IT/S NOT LOOKING LIKE MUCH MORE THAN CLOUD COVER.
MOST MODELS DO SHOW A BETTER CHANCE FOR AT LEAST SPRINKLES JUST S OF
MENOMINEE AND LOWER MI THURSDAY AFTERNOON...BUT NOTHING FOR UPPER
MI. THIS IS HANDLES WELL IN OUR PREVIOUS FCST...SO LIMITED CHANGES
WILL BE NEEDED. ANY REAL WARM UP WILL HAVE TO WAIT UNTIL THE
WEEKEND...AS COOL N WINDS OFF LAKE SUPERIOR AND 850MB TEMPS ON
THURSDAY HOVERING AROUND 2C. 850MB TEMPS MAY GET DOWN TO -3 OR -4C E
BY 12Z FRIDAY...LEADING TO ANOTHER CHILLY MORNING. OVERNIGHT LOWS IN
THE 30S WILL BE COMMON BOTH WEDNESDAY NIGHT AND THURSDAY NIGHT.

SATURDAY WILL BE A TRANSITION DAY AS THE CANADIAN HIGH EDGES TO THE
SE AND SLIGHTLY WARMER AIR MOVES IN. IT WILL END UP BEING THE
WARMEST DAY THIS WEEK WITH HIGHS NEAR NORMAL /60S TO AROUND 70F/.

THE 500MB RIDGE WILL STRENGTHEN OVER THE CWA SUNDAY AND MONDAY AS
THE SFC RIDGE LINGERS. THE GFS IS A BIT MORE AGGRESSIVE WITH THE MAIN
500MB TROUGH DIGGING BACK INTO THE UPPER GREAT LAKES ON
MONDAY...LEADING TO A STRONGER SYSTEM OVERALL. THE APEX OF THE RIDGE
WILL BE NEARBY AROUND 12Z MONDAY...WITH SW FLOW RETURNING AHEAD OF A
SFC LOW NEARING FROM THE SW. THE BEST CHANCE OF PRECIP IN THIS
LONGER TERM PERIOD WILL LIKELY HOLD OFF UNTIL THE DAYTIME HOURS
MONDAY. THERE IS STILL SOME UNCERTAINTY AS TO WHETHER THE BEST
CHANCE WILL BE OVER THE N OR S...DEPENDING ON THE TRACK/STRENGTH OF
THE SFC LOW AND NEARING SHORTWAVE ENERGY.
&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 728 AM EDT TUE MAY 19 2015

WRAPAROUND MOISTURE WILL CONTINUE TO AFFECT ALL SITES INTO THE
MORNING HOURS WITH MVFR TO OCCASIONAL IFR CONDITIONS IN LIGHT SNOW
SHOWERS. VFR CONDITIONS WITH MUCH DRIER AIR AND MIXING MOVE INTO
KIWD EARLY THIS AFTERNOON AND INTO KCMX AND KSAW MID TO LATE
AFTERNOON AS NNW GRADUALLY DIMINISH.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 506 AM EDT TUE MAY 19 2015

LOW PRES CENTERED OVER QUEBEC WILL CONTINUE TO LIFT NE TODAY AS HIGH
PRES GRADUALLY BUILDS IN FM THE WEST. NNW WINDS TO 20 TO 30 KNOTS
(HIGHEST EAST HALF) THIS MORNING WILL DIMINISH W TO E THIS
AFTERNOON/TONIGHT AS THE HIGH BUILDS IN FM THE WEST DECREASING THE
PRES GRADIENT. WED THRROUGH SAT...WINDS WILL BE UNDER 20KT AS SFC
HIGH PRES REMAINS IN CONTROL THROUGH MUCH OF THE PERIOD.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...VOSS
LONG TERM...KF
AVIATION...VOSS
MARINE...VOSS



AREA FORECAST DISCUSSION...UPDATED AVIATION

NWS ST LOUIS MO

 650 AM CDT Tue May 19 2015

.SHORT TERM:  (Through Late This Afternoon)
Issued at 425 AM CDT Tue May 19 2015

High pressure building into Missouri and Illinois brings cool
temperatures and calm weather to the area today. Expect highs in
the 60s and light winds out of the northwest to north.

42

.LONG TERM:  (Tonight through Monday)
Issued at 425 AM CDT Tue May 19 2015

An upper disturbance induces a surface wave along a pre-existing
baroclinic zone stretching across the south central and
southeastern states. A southerly LLJ ahead of the low pressure
system interacts with the boundary to spread showers/thunderstorms
northward into the forecast area as early as late tonight.
Precipitation coverage seems most widespread on Wednesday, then
tapers off on Wednesday night when the surface wave both dampens
and moves farther away from the forecast area. High pressure
builds back into the region on Thursday for another day of cooler
temperatures and calm weather. The synoptic pattern for this
weekend resembles the synoptic pattern for the last two weekends.
A few periods of active weather appear likely between Friday and
Monday.

42

&&

.AVIATION:  (For the 12z TAFs through 12z Wednesday Morning)
Issued at 650 AM CDT Tue May 19 2015

Over the last few hours some of the cold air SC (with MVFR cigs) in
the wake of the Great Lakes low has managed to drift south and
sneak into our far N counties...including KUIN. 00z and 06z
guidance as well as the latest RUC solutions suggest that this
cloudiness should become stationary and quickly dissipate over the
next few hours. Otherwise and elsewhere...VFR conditions are
expected today, with cloudiness limited to some high level CI
spreading from the Plains into the mid-Mississippi Valley. Mid and
high clouds will then slowly thicken overnight as WAA ramps up
ahead of upper level trof. Overnight synoptic guidance suggests
that only threat of rain during this TAF period will be limited to
KCOU just before daybreak, with cigs here possibily lowering to
around 5kft by this time.

Specifics for KSTL: Clouds aoa 10kft expected today and into
tonight, with north-northeast winds aob 10kts. Ceilings should
begin to lower on Wednesday morning as WAA intensifies across
area, with ceilings dropping into the 3-5kt range by late morning
as rain begins to push into the area.

Truett

&&

.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&

$$

WFO LSX







AREA FORECAST DISCUSSION

NWS CLEVELAND OH

 722 AM EDT TUE MAY 19 2015

.SYNOPSIS...
HIGH PRESSURE CENTERED OVER THE DAKOTAS WILL BUILD SOUTHEAST
INTO THE PLAIN STATES AND EXTEND A RIDGE INTO THE REGION THROUGH
MID WEEK. FRIDAY MORNING A COLD FRONT WILL DROP SOUTH ACROSS THE
GREAT LAKES AND INTO NORTHERN OHIO. HIGH PRESSURE WILL
FOLLOW...BUILDING ACROSS THE REGION SATURDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATE...COLD FRONT NOW THROUGH MOST OF THE AREA WITH WINDS NOW
FROM THE WNW. ADJUSTED HOURLY TEMPS INTO THE AFTERNOON TOWARD
THE HRRR TO CAPTURE THE NON DIURNAL TRENDS. CLOUDS ADVANCING
TOWARD THE AREA FROM THE NORTHWEST ASSOCIATED WITH WRAP AROUND
MOISTURE AND COOL AIR ALOFT. CURRENT TIMING STILL LOOKS GOOD
GETTING INTO KTOL AREA BETWEEN 8-9AM AND KCLE A LITTLE AFTER NOON
SO NO CHANGES TO SKY GRIDS.

ORIGINAL...COLD FRONT PROGRESSING EAST ACROSS THE AREA EARLY THIS
MORNING WITH SWLY FLOW KCLE-KMFD AND NWLY FLOW AT KTOL AND KFDY.
AT THIS TIME NO PRECIP IS ASSOCIATED WITH THE BOUNDARY AND NON IS
EXPECTED. SKIES CLEAR 100 MILES EITHER SIDE OF THE FRONT WITH
CLEARING JUST ABOUT TO ENTER NWRN PA. ON THE OTHER HAND...WRAP
AROUND MOISTURE/CLOUDS DROPPING ESE ACROSS SOUTHERN LAKE MI. THIS
LOW LEVEL CLOUD DECK IS EXPECTED INTO NWRN TOL AREA 12-13Z BASED
ON TIMING OF CURRENT MOVEMENT. CLOUDS REACH KCLE AROUND 17Z. HIGH
TODAY IN THE 60S BUT TEMPS WILL BE STEADY/SLOWLY FALLING POST
FRONT.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
NO BIG CHANGE TO THE SHORT TERM THINKING. MUCH COOLER AND
GENERALLY DRY CONDITIONS CONTINUE TO BE EXPECTED DURING THIS
PERIOD AS HIGH PRESSURE TO OUR WEST FORCES MUCH COOLER AIR INTO
THE REGION. THIS HIGH WILL GRADUALLY BUILD EAST THROUGH MID WEEK.
THERE IS STILL A POTENTIAL FOR FROST EARLY WEDNESDAY MORNING WHERE
SKIES CLEAR. WILL NOT ISSUE AN ADVISORY JUST YET AS TEMPS MARGINAL
AND CLOUDS STILL MOVING TOWARD THE AREA. A WEAK SHORTWAVE EARLY
THURSDAY COULD PRODUCE A BRIEF SPRINKLE. PUT IN SLIGHT CHANCE FOR
MOST BUT WILL NOT GET INTO THE ZFP. ANOTHER COLD FRONT WILL DROP
ACROSS THE REGION FRIDAY AS UPPER TROF DIGS INTO QUEBEC. THIS
SHOULD AFFECT NORTHEAST OHIO AND NWRN PA TEMPS THE MOST BASED ON
PACKING AND ORIENTATION. HIGHS WEDNESDAY FROM THE MID 50S TO MID
60S. EXPECT A GRADUAL WARMUP INTO THURSDAY. FRIDAY WESTERN
COUNTIES COULD TACK ON ANOTHER COUPLE DEGREES BUT NERN OHIO AND
NWRN PA LIKELY DROP BACK TO 60 TO 65.

&&

.LONG TERM /SATURDAY THROUGH MONDAY/...
UPPER LEVEL RIDGE BECOMES AMPLIFIED OVER THE WEEKEND ACROSS THE
MISSISSIPPI VALLEY REGION. THIS WILL HELP TO BUILD SURFACE HIGH
PRESSURE AS IT MOVES EAST OVER THE FORECAST AREA. EVENTUALLY...THE
SURFACE HIGH PUSHES EAST TO THE EAST COAST BY SUNDAY MORNING. THIS
WILL SET UP ANOTHER ROUND OF WARM AIR ADVECTION INTO THE FORECAST
AREA OVER THE WEEKEND. THE UNFORTUNATE SCENARIO WILL OCCUR WHERE THE
GULF OF MEXICO WILL OPEN UP AND SEND A STREAM OF MOISTURE NORTH
ACROSS EASTERN TEXAS INTO THE FORECAST AREA. THIS CONVEYOR BELT OF
MOISTURE WILL UNDOUBTEDLY BRING WITH IT A THREAT FOR SHOWERS AND
THUNDERSTORMS DURING THE LATTER HALF OF THE MEMORIAL DAY WEEKEND.
WILL CONTINUE THE GRADUAL INCREASE OF SHOWERS AND THUNDERSTORMS
SUNDAY INTO MONDAY FROM WEST TO EAST. HAVE A GUT FEELING WE MAY NEED
TO UP POPS TO LIKELY ALL AREAS FOR MONDAY. TEMPERATURE FORECAST IS A
TOUGH ONE AS WE GET INTO THE WEEKEND AND MONDAY AS THEY WILL BE
HIGHLY DEPENDENT ON HOW MUCH SUN BREAKS THROUGH THE OVERCAST BETWEEN
SHOWERS AND THUNDERSTORMS. IF WE GET A PERIOD OF SUN ANY OF THOSE
DAYS...MAX TEMPERATURES WILL BE UNDER FORECAST.

&&

.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
COLD FRONT SHOULD CONTINUE TO MOVE EAST THROUGH THE REST OF THE
MORNING HOURS. SKIES CLEARED OVER MUCH OF THE FORECAST AREA. THE
EXCEPTION IS THE EXTREME EAST WHERE SOME LOWER CLOUDS FORMED BUT
APPEARS IT SHOULD MOVE EAST AS WELL. A STRATOCUMULUS DECK AROUND
3500 TO 4000 FEET WILL MOVE EAST INTO THE AREA THIS MORNING AND
LINGER OVER MOST OF THE AREA THROUGH MUCH OF THE TAF PERIOD. WINDS
WILL REMAIN AT 10 TO 15 KNOTS UNTIL THIS EVENING AND THEN
DIMINISH.

.OUTLOOK... NON-VFR POSSIBLE BEHIND A COLD FRONT IN NE OH/NW PA
TUESDAY NIGHT.

&&

.MARINE...
A SMALL CRAFT ADVISORY WILL BE NEEDED THIS AFTERNOON AND EARLY
TONIGHT AS WINDS INCREASE OUT OF THE WEST AND BECOME NORTHERLY
ACROSS THE LAKE. WINDS DO DIMINISH STARTING TONIGHT AND THEN `
CONSIDERABLY WEDNESDAY INTO WEDNESDAY NIGHT. WINDS DO INCREASE A
TAD OUT OF THE SOUTHWEST ON THURSDAY AHEAD OF A WEAK COLD FRONT
THAT MOVES SOUTHEAST ACROSS THE LAKE. AT THIS TIME...IT LOOKS LIKE
WINDS SHOULD BE WEAK ENOUGH TO AVOID SMALL CRAFT ADVISORIES. WINDS
THEN BECOME LIGHT AND VARIABLE AS HIGH PRESSURE BUILDS SOUTHEAST
ACROSS THE LAKE HEADING INTO THE WEEKEND.

&&

.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 10 PM EDT
     THIS EVENING FOR LEZ148-149.

&&

$$
SYNOPSIS...TK
NEAR TERM...TK
SHORT TERM...TK
LONG TERM...LOMBARDY
AVIATION...LOMBARDY
MARINE...LOMBARDY







AREA FORECAST DISCUSSION

NWS CLEVELAND OH

 630 AM EDT TUE MAY 19 2015

.SYNOPSIS...
HIGH PRESSURE CENTERED OVER THE DAKOTAS WILL BUILD SOUTHEAST
INTO THE PLAIN STATES AND EXTEND A RIDGE INTO THE REGION THROUGH
MID WEEK. FRIDAY MORNING A COLD FRONT WILL DROP SOUTH ACROSS THE
GREAT LAKES AND INTO NORTHERN OHIO. HIGH PRESSURE WILL
FOLLOW...BUILDING ACROSS THE REGION SATURDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATE...COLD FRONT NOW THROUGH MOST OF THE AREA WITH WINDS NOW
FROM THE WNW. ADJUSTED HOURLY TEMPS INTO THE AFTERNOON TOWARD
THE HRRR TO CAPTURE THE NON DIURNAL TRENDS. CLOUDS ADVANCING
TOWARD THE AREA FROM THE NORTHWEST ASSOCIATED WITH WRAP AROUND
MOISTURE AND COOL AIR ALOFT. CURRENT TIMING STILL LOOKS GOOD
GETTING INTO KTOL AREA BETWEEN 8-9AM AND KCLE A LITTLE AFTER NOON
SO NO CHANGES TO SKY GRIDS.

ORIGINAL...COLD FRONT PROGRESSING EAST ACROSS THE AREA EARLY THIS
MORNING WITH SWLY FLOW KCLE-KMFD AND NWLY FLOW AT KTOL AND KFDY.
AT THIS TIME NO PRECIP IS ASSOCIATED WITH THE BOUNDARY AND NON IS
EXPECTED. SKIES CLEAR 100 MILES EITHER SIDE OF THE FRONT WITH
CLEARING JUST ABOUT TO ENTER NWRN PA. ON THE OTHER HAND...WRAP
AROUND MOISTURE/CLOUDS DROPPING ESE ACROSS SOUTHERN LAKE MI. THIS
LOW LEVEL CLOUD DECK IS EXPECTED INTO NWRN TOL AREA 12-13Z BASED
ON TIMING OF CURRENT MOVEMENT. CLOUDS REACH KCLE AROUND 17Z. HIGH
TODAY IN THE 60S BUT TEMPS WILL BE STEADY/SLOWLY FALLING POST
FRONT.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
NO BIG CHANGE TO THE SHORT TERM THINKING. MUCH COOLER AND
GENERALLY DRY CONDITIONS CONTINUE TO BE EXPECTED DURING THIS
PERIOD AS HIGH PRESSURE TO OUR WEST FORCES MUCH COOLER AIR INTO
THE REGION. THIS HIGH WILL GRADUALLY BUILD EAST THROUGH MID WEEK.
THERE IS STILL A POTENTIAL FOR FROST EARLY WEDNESDAY MORNING WHERE
SKIES CLEAR. WILL NOT ISSUE AN ADVISORY JUST YET AS TEMPS MARGINAL
AND CLOUDS STILL MOVING TOWARD THE AREA. A WEAK SHORTWAVE EARLY
THURSDAY COULD PRODUCE A BRIEF SPRINKLE. PUT IN SLIGHT CHANCE FOR
MOST BUT WILL NOT GET INTO THE ZFP. ANOTHER COLD FRONT WILL DROP
ACROSS THE REGION FRIDAY AS UPPER TROF DIGS INTO QUEBEC. THIS
SHOULD AFFECT NORTHEAST OHIO AND NWRN PA TEMPS THE MOST BASED ON
PACKING AND ORIENTATION. HIGHS WEDNESDAY FROM THE MID 50S TO MID
60S. EXPECT A GRADUAL WARMUP INTO THURSDAY. FRIDAY WESTERN
COUNTIES COULD TACK ON ANOTHER COUPLE DEGREES BUT NERN OHIO AND
NWRN PA LIKELY DROP BACK TO 60 TO 65.

&&

.LONG TERM /SATURDAY THROUGH MONDAY/...
UPPER LEVEL RIDGE BECOMES AMPLIFIED OVER THE WEEKEND ACROSS THE
MISSISSIPPI VALLEY REGION. THIS WILL HELP TO BUILD SURFACE HIGH
PRESSURE AS IT MOVES EAST OVER THE FORECAST AREA. EVENTUALLY...THE
SURFACE HIGH PUSHES EAST TO THE EAST COAST BY SUNDAY MORNING. THIS
WILL SET UP ANOTHER ROUND OF WARM AIR ADVECTION INTO THE FORECAST
AREA OVER THE WEEKEND. THE UNFORTUNATE SCENARIO WILL OCCUR WHERE THE
GULF OF MEXICO WILL OPEN UP AND SEND A STREAM OF MOISTURE NORTH
ACROSS EASTERN TEXAS INTO THE FORECAST AREA. THIS CONVEYOR BELT OF
MOISTURE WILL UNDOUBTEDLY BRING WITH IT A THREAT FOR SHOWERS AND
THUNDERSTORMS DURING THE LATTER HALF OF THE MEMORIAL DAY WEEKEND.
WILL CONTINUE THE GRADUAL INCREASE OF SHOWERS AND THUNDERSTORMS
SUNDAY INTO MONDAY FROM WEST TO EAST. HAVE A GUT FEELING WE MAY NEED
TO UP POPS TO LIKELY ALL AREAS FOR MONDAY. TEMPERATURE FORECAST IS A
TOUGH ONE AS WE GET INTO THE WEEKEND AND MONDAY AS THEY WILL BE
HIGHLY DEPENDENT ON HOW MUCH SUN BREAKS THROUGH THE OVERCAST BETWEEN
SHOWERS AND THUNDERSTORMS. IF WE GET A PERIOD OF SUN ANY OF THOSE
DAYS...MAX TEMPERATURES WILL BE UNDER FORECAST.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
COLD FRONT IS GRADUALLY PUSHING EAST ACROSS THE WESTERN HALF OF
THE FORECAST AREA AT THIS TIME AND SHOULD CONTINUE TO MOVE EAST
THROUGH THE REST OF THE MORNING HOURS. SKIES CLEARING OUT WITH THE
COLD FRONT FOR A PERIOD OF TIME. A STRATOCUMULUS DECK AROUND 4K
FEET WILL MOVE EAST INTO THE AREA THIS MORNING AND LINGER OVER
MOST OF THE AREA THROUGH MUCH OF THE TAF PERIOD. WINDS WILL
INCREASE ALONG THE FRONTAL BOUNDARY AND REMAIN AT 10 TO 15 KNOTS
UNTIL THIS EVENING AND THEN DIMINISH. LOW CLOUDS AT YOUNGSTOWN AND
AKRON CANTON SHOULD GRADUALLY SHIFT EAST THIS MORNING AS WELL.

.OUTLOOK... NON-VFR POSSIBLE BEHIND A COLD FRONT IN NE OH/NW PA
TUESDAY NIGHT.

&&

.MARINE...
A SMALL CRAFT ADVISORY WILL BE NEEDED THIS AFTERNOON AND EARLY
TONIGHT AS WINDS INCREASE OUT OF THE WEST AND BECOME NORTHERLY
ACROSS THE LAKE. WINDS DO DIMINISH STARTING TONIGHT AND THEN `
CONSIDERABLY WEDNESDAY INTO WEDNESDAY NIGHT. WINDS DO INCREASE A
TAD OUT OF THE SOUTHWEST ON THURSDAY AHEAD OF A WEAK COLD FRONT
THAT MOVES SOUTHEAST ACROSS THE LAKE. AT THIS TIME...IT LOOKS LIKE
WINDS SHOULD BE WEAK ENOUGH TO AVOID SMALL CRAFT ADVISORIES. WINDS
THEN BECOME LIGHT AND VARIABLE AS HIGH PRESSURE BUILDS SOUTHEAST
ACROSS THE LAKE HEADING INTO THE WEEKEND.

&&

.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 10 PM EDT
     THIS EVENING FOR LEZ148-149.

&&

$$
SYNOPSIS...TK
NEAR TERM...TK
SHORT TERM...TK
LONG TERM...LOMBARDY
AVIATION...LOMBARDY
MARINE...LOMBARDY






AREA FORECAST DISCUSSION

NWS STATE COLLEGE PA

 831 AM EDT TUE MAY 19 2015

.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS CENTRAL PENNSYLVANIA TODAY WITH A
MARGINAL/ISOLATED SEVERE WEATHER RISK FROM THE EASTERN COAL REGION
INTO THE POCONOS. A COOLER AND MAINLY DRY WEATHER PATTERN WITH
NEAR TO BELOW NORMAL TEMPERATURES WILL GRIP THE REGION FROM
WEDNESDAY INTO THE WEEKEND...FOLLOWED BY A GRADUAL WARMING TREND
WITH UNSETTLED CONDITIONS THROUGH EARLY NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
815 AM UPDATE...
SHOWERS EXITING TO THE EAST. COLD FRONT BARELY TO THE WEST OF BFD
AND PIT...MOVING SLOWLY BUT STEADILY. THE FRONT WILL BE HALF WAY
THROUGH THE CWA AROUND NOON BUT TAKE ALL AFTERNOON AND MAYBE UNTIL
EARLY EVENING DAY TO GET TOTALLY OUT OF THE CWA. HIGH MOISTURE IN
THE EAST AND ALL DAY TO COOK/MIX WILL MAKE THE KETTLE BUBBLE WHEN
THE FRONT APPROACHES/PASSES. HAVE DELAYED EXIT OF STORMS FROM
LANCASTER CO BY AN HOUR OR TWO.

PREV...
09Z RADAR SHOWS WHAT IS LEFT OF MEASURABLE SHOWERS MOVG EWD ALONG
RDG-LNS LINE. WILL TAPER DOWN POPS THROUGH MID MORNING BASED ON
RADAR TRENDS AND HRRR. SUBTLE BACKDOOR TYPE FRONT HAS ALLOWED
MARINE AIR/EASTERLY LLVL FLOW TO REACH AS FAR WEST AS THE SUSQ
RIVER WITH WDSPRD LOW CIGS AND FOG EXPECTED TO PERSIST THROUGH
DAYBREAK. TO THE WEST ALONG THE ALLEGHANY FRONT...WEAK BUT MOIST
UPSLOPE IS PROMOTING LOW CIGS AND FOG ALONG THE RT 219 CORRIDOR.

SHORTWAVE CURRENTLY MOVING THROUGH THE UPPER GREAT LAKES WILL
TEAM WITH ADDITIONAL ENERGY DROPPING DOWN AROUND THE HUDSON BAY
UPPER TROUGH TO FLATTEN THE ANOMALOUS RIDGE OVER THE NORTHEASTERN
U.S. ONCE THE LOW CLOUDS/FOG BURN OFF THIS MORNING...STRONG PRE-
FRONTAL BOUNDARY LAYER WARMING SHOULD PROVE MORE THAN ADEQUATE FOR
CONVECTION WITH HRRR SHOWING DEVELOPMENT EAST OF THE SUSQ RIVER
BY 18-19Z. THE SPC DAY 1 MARGINAL RISK JUST CLIPS EAST-CENTRAL PA
FROM THE COAL REGION ENEWD INTO THE POCONOS WITH INCREASING SHEAR
TO THE NORTH. HOWEVER DESPITE WEAKER FLOW ALOFT...CANT RULE OUT
THREAT FOR GUSTY WINDS/SMALL HAIL IN MORE CAPE-DRIVEN STORMS
WITHIN STEEP LLVL LAPSE RATE ENVIRONMENT OVER THE LWR SQV. HEAVY
DOWNPOURS COULD POSE MINOR FLOOD THREAT PROBABLY MORE SO CONFINED
TO URBAN/POOR DRAINAGE AREAS VS. SMALL STREAMS AND CREEKS GIVEN
DRY ANTECEDENT CONDITIONS AND BELOW NORMAL STREAM FLOWS FOR THIS
TIME OF YEAR. ANY EARLY EVENING ACTIVITY OVER FAR ERN SXNS SHOULD
PUSH OUT OF THE CWA AFTER 00Z AS NOTICEABLY DRIER AIR SPREADS
ACROSS THE AREA IN THE WAKE OF THE COLD FRONT.

&&

.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
A COOLER BROAD CYCLONIC FLOW WILL BEGIN TO GRIP THE REGION ON
WEDNESDAY WITH DAYTIME HIGHS SOME 15-20F COOLER THAN TODAY. THE
COOLER AIR ALOFT SHOULD PROMOTE AFTN CU DEVELOPMENT WITH A NW
BREEZE ADDING TO THE RELATIVE CHILL. THE MODELS SHOW A SHORTWAVE
TROUGH MOVING QUICKLY ESEWD FROM THE UPPER GREAT LAKES THROUGH
CENTRAL APPALACHIANS AND NORTHERN MID ATLANTIC STATES THU-FRI WITH
SOME SHOWERS POSSIBLE ON THU. A SFC LOW IS FCST TO EMERGE OFF THE
CAROLINAS INTO FRIDAY WITH SOME SPREAD IN THE GUIDANCE...OWING TO
VARIABILITY IN THE HANDLING OF THE PARENT SHORTWAVE. A SECONDARY
COLD FRONT SHOULD CROSS THE AREA ON FRIDAY FOLLOWED BY ANOTHER
SHOT OF COOL AIR. CONFIDENCE REMAINS ON THE LOW SIDE FOR FROST
THU MORNING IN THE NORTH AS THE PATTERN DOES NOT LOOK FAVORABLE
OR CONDUCIVE.

&&

.LONG TERM /SATURDAY THROUGH MONDAY/...
CONFIDENCE IN FROST POTENTIAL IS MUCH HIGHER ON SATURDAY MORNING
OVER THE NORTH-CNTRL ZONES WITH A LARGE AREA OF HP FCST TO SETTLE
OVER CENTRAL PA. WILL ADD FROST WORDING TO THE HWO FOR THE 3 ZONES
THAT ARE STILL NOT IN THE GROWING SEASON /MCKEAN-POTTER-ELK/. DRY
WX SHOULD HOLD ON UNTL EARLY NEXT WEEK AS THE UPPER RIDGE BUILDS
AGAIN OVER THE ERN U.S. AN E-W FRONTAL BOUNDARY COULD BE A FOCUS
FOR PCPN AS IT PIVOTS AND LIFTS NWD IN A SIMILAR FASHION TO THIS
PAST WEEKEND. CLOSELY FOLLOWED THE ROBUST NATIONAL SUPERBLEND
PROTOTYPE GUIDANCE FOR TEMPERATURES WHICH FAVORS A GRADUAL
WARMING TREND FOR THE AREA BEYOND THE END OF THE PERIOD.

&&

.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
PATCHY DENSE FOG AND LOW STRATOCU IS CONTINUING THROUGH THE
EASTERN TAF SITES. EXPECT FOR THIS TO PERSIST OVER THE NEXT FEW
HOURS...LIFTING BETWEEN 13Z TO 15Z. IFR AT BFD AND JST WILL
PERSIST AS WELL AND BY 14Z SHOULD LIFT TO MVFR ADN BY 16Z BE VFR.

THE COLD FRONT IS SLOWLY MOVING EASTWARD AND WILL MOVE THROUGH
THIS AFTERNOON. STILL CAN/T RULE OUT AN ISOLD SHRA/TSRA ACROSS
EASTERN PA ARND MIDDAY WITH PASSAGE OF THE FRONT.
OTHERWISE...EXPECT A RETURN TO WIDESPREAD VFR CONDS...AS A GUSTY
WEST WIND BRINGS MUCH DRIER AIR INTO THE REGION BEHIND THE COLD
FRONT.

GUSTY WINDS SHOULD SUBSIDE BY EARLY EVENING...WITH STRONG
NORTHWESTERLY FLOW INCREASING OVERNIGHT WHICH COULD MIX DOWN
STRONTER WINDS EARLY WEDNESDAY MORNING.

OUTLOOK...

WED-SAT...NO SIG WX EXPECTED.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...STEINBUGL
NEAR TERM...DANGELO/STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...STEINBUGL
AVIATION...FITZGERALD/CERU




AREA FORECAST DISCUSSION

NWS STATE COLLEGE PA

 744 AM EDT TUE MAY 19 2015

.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS CENTRAL PENNSYLVANIA TODAY WITH A
MARGINAL/ISOLATED SEVERE WEATHER RISK FROM THE EASTERN COAL REGION
INTO THE POCONOS. A COOLER AND MAINLY DRY WEATHER PATTERN WITH
NEAR TO BELOW NORMAL TEMPERATURES WILL GRIP THE REGION FROM
WEDNESDAY INTO THE WEEKEND...FOLLOWED BY A GRADUAL WARMING TREND
WITH UNSETTLED CONDITIONS THROUGH EARLY NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
09Z RADAR SHOWS WHAT IS LEFT OF MEASURABLE SHOWERS MOVG EWD ALONG
RDG-LNS LINE. WILL TAPER DOWN POPS THROUGH MID MORNING BASED ON
RADAR TRENDS AND HRRR. SUBTLE BACKDOOR TYPE FRONT HAS ALLOWED
MARINE AIR/EASTERLY LLVL FLOW TO REACH AS FAR WEST AS THE SUSQ
RIVER WITH WDSPRD LOW CIGS AND FOG EXPECTED TO PERSIST THROUGH
DAYBREAK. TO THE WEST ALONG THE ALLEGHANY FRONT...WEAK BUT MOIST
UPSLOPE IS PROMOTING LOW CIGS AND FOG ALONG THE RT 219 CORRIDOR.

SHORTWAVE CURRENTLY MOVING THROUGH THE UPPER GREAT LAKES WILL
TEAM WITH ADDITIONAL ENERGY DROPPING DOWN AROUND THE HUDSON BAY
UPPER TROUGH TO FLATTEN THE ANOMALOUS RIDGE OVER THE NORTHEASTERN
U.S. ONCE THE LOW CLOUDS/FOG BURN OFF THIS MORNING...STRONG PRE-
FRONTAL BOUNDARY LAYER WARMING SHOULD PROVE MORE THAN ADEQUATE FOR
CONVECTION WITH HRRR SHOWING DEVELOPMENT EAST OF THE SUSQ RIVER
BY 18-19Z. THE SPC DAY 1 MARGINAL RISK JUST CLIPS EAST-CENTRAL PA
FROM THE COAL REGION ENEWD INTO THE POCONOS WITH INCREASING SHEAR
TO THE NORTH. HOWEVER DESPITE WEAKER FLOW ALOFT...CANT RULE OUT
THREAT FOR GUSTY WINDS/SMALL HAIL IN MORE CAPE-DRIVEN STORMS
WITHIN STEEP LLVL LAPSE RATE ENVIRONMENT OVER THE LWR SQV. HEAVY
DOWNPOURS COULD POSE MINOR FLOOD THREAT PROBABLY MORE SO CONFINED
TO URBAN/POOR DRAINAGE AREAS VS. SMALL STREAMS AND CREEKS GIVEN
DRY ANTECEDENT CONDITIONS AND BELOW NORMAL STREAM FLOWS FOR THIS
TIME OF YEAR. ANY EARLY EVENING ACTIVITY OVER FAR ERN SXNS SHOULD
PUSH OUT OF THE CWA AFTER 00Z AS NOTICEABLY DRIER AIR SPREADS
ACROSS THE AREA IN THE WAKE OF THE COLD FRONT.

&&

.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
A COOLER BROAD CYCLONIC FLOW WILL BEGIN TO GRIP THE REGION ON
WEDNESDAY WITH DAYTIME HIGHS SOME 15-20F COOLER THAN TODAY. THE
COOLER AIR ALOFT SHOULD PROMOTE AFTN CU DEVELOPMENT WITH A NW
BREEZE ADDING TO THE RELATIVE CHILL. THE MODELS SHOW A SHORTWAVE
TROUGH MOVING QUICKLY ESEWD FROM THE UPPER GREAT LAKES THROUGH
CENTRAL APPALACHIANS AND NORTHERN MID ATLANTIC STATES THU-FRI WITH
SOME SHOWERS POSSIBLE ON THU. A SFC LOW IS FCST TO EMERGE OFF THE
CAROLINAS INTO FRIDAY WITH SOME SPREAD IN THE GUIDANCE...OWING TO
VARIABILITY IN THE HANDLING OF THE PARENT SHORTWAVE. A SECONDARY
COLD FRONT SHOULD CROSS THE AREA ON FRIDAY FOLLOWED BY ANOTHER
SHOT OF COOL AIR. CONFIDENCE REMAINS ON THE LOW SIDE FOR FROST
THU MORNING IN THE NORTH AS THE PATTERN DOES NOT LOOK FAVORABLE
OR CONDUCIVE.

&&

.LONG TERM /SATURDAY THROUGH MONDAY/...
CONFIDENCE IN FROST POTENTIAL IS MUCH HIGHER ON SATURDAY MORNING
OVER THE NORTH-CNTRL ZONES WITH A LARGE AREA OF HP FCST TO SETTLE
OVER CENTRAL PA. WILL ADD FROST WORDING TO THE HWO FOR THE 3 ZONES
THAT ARE STILL NOT IN THE GROWING SEASON /MCKEAN-POTTER-ELK/. DRY
WX SHOULD HOLD ON UNTL EARLY NEXT WEEK AS THE UPPER RIDGE BUILDS
AGAIN OVER THE ERN U.S. AN E-W FRONTAL BOUNDARY COULD BE A FOCUS
FOR PCPN AS IT PIVOTS AND LIFTS NWD IN A SIMILAR FASHION TO THIS
PAST WEEKEND. CLOSELY FOLLOWED THE ROBUST NATIONAL SUPERBLEND
PROTOTYPE GUIDANCE FOR TEMPERATURES WHICH FAVORS A GRADUAL
WARMING TREND FOR THE AREA BEYOND THE END OF THE PERIOD.

&&

.AVIATION /11Z TUESDAY THROUGH SATURDAY/...
PATCHY DENSE FOG AND LOW STRATOCU IS CONTINUING THROUGH THE
EASTERN TAF SITES. EXPECT FOR THIS TO PERSIST OVER THE NEXT FEW
HOURS...LIFTING BETWEEN 13Z TO 15Z. IFR AT BFD AND JST WILL
PERSIST AS WELL AND BY 14Z SHOULD LIFT TO MVFR ADN BY 16Z BE VFR.

THE COLD FRONT IS SLOWLY MOVING EASTWARD AND WILL MOVE THROUGH
THIS AFTERNOON. STILL CAN/T RULE OUT AN ISOLD SHRA/TSRA ACROSS
EASTERN PA ARND MIDDAY WITH PASSAGE OF THE FRONT.
OTHERWISE...EXPECT A RETURN TO WIDESPREAD VFR CONDS...AS A GUSTY
WEST WIND BRINGS MUCH DRIER AIR INTO THE REGION BEHIND THE COLD
FRONT.

GUSTY WINDS SHOULD SUBSIDE BY EARLY EVENING...WITH STRONG
NORTHWESTERLY FLOW INCREASING OVERNIGHT WHICH COULD MIX DOWN
STRONTER WINDS EARLY WEDNESDAY MORNING.

OUTLOOK...

WED-SAT...NO SIG WX EXPECTED.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...STEINBUGL
AVIATION...FITZGERALD/CERU




AREA FORECAST DISCUSSION

NWS AUSTIN/SAN ANTONIO TX

 832 AM CDT TUE MAY 19 2015

.UPDATE...
MORNING SHOWER ACTIVITY IS INCREASING OVER THE NORTHERN COUNTIES
AS MOISTURE FEEDS INTO THE MCV IN THE FWD CWA. UPPED POPS A BIT IN
THIS REGION TO ACCOUNT FOR THIS NEW ACTIVITY. OTHERWISE...NO MAJOR
CHANGES WERE MADE TO THE FORECAST.

&&

.PREV DISCUSSION... /ISSUED 645 AM CDT TUE MAY 19 2015/

DISCUSSION...12Z AVIATION BELOW.

AVIATION...BKN-OVC MVFR TO IFR CEILINGS WITH STRATUS THIS
MORNING ACROSS SOUTH-CENTRAL TEXAS. REMNANTS OF OVERNIGHT
CONVECTIVE COMPLEX IS PASSING NORTH OF THE CWA THIS MORNING.
A FEW SHRA AND ISOLATED TSTMS POSSIBLE THROUGH THE MORNING ACROSS
THE HILL COUNTRY AND CENTRAL TEXAS NEAR AUS...FEEDING INTO WHAT IS
LEFT OF THE MCV FARTHER TO THE NORTH. OTHERWISE...CEILINGS SLOWLY
RISING AFTER 16Z AND EVENTUALLY BECOMING VFR 18Z-20Z.
MVFR CEILINGS RE-DEVELOPING 03Z-05Z AUS/SAT/SSF AND BECOMING IFR
06Z-08Z. MVFR CEILINGS RE-DEVELOP AT DRT 06Z-08Z.

PREV DISCUSSION... /ISSUED 357 AM CDT TUE MAY 19 2015/

SHORT TERM (TODAY THROUGH WEDNESDAY)...
A SLOW MOVING MCS OVER WEST CENTRAL TX IS PRODUCING FLASH
FLOODING OVER THE SAN ANGELO AREA EARLY THIS MORNING. IN THE PAST
HOUR OR SO...THE SOUTHERN PORTION OF THE COMPLEX IS TAKING OVER
AND SHOWING A MORE FORWARD PROPAGATING TREND. HI-RES MODEL
SUGGESTED CORFIDI VECTORS SUGGEST THE STORMS TO REMAIN MOSTLY IN
THE FORECAST AREAS TO THE NORTH...BUT AS NOTED IN THE LATEST
SPENES AND FFGMPD DISCUSSIONS...DIFFLUENCE ALOFT IS CAUSING HI-
RES SOLUTIONS TO SLOW DOWN THE MOTION WITH THE SYSTEM EXPECTED
BECOME MORE DISORGANIZED AND SLOWER TOWARD DAYBREAK. UPSHEAR
PROPAGATION VECTORS AND MODEL DEPICTIONS OF AN INCREASING MOISTURE
TAP LATER IN THE MORNING WOULD SUGGEST THAT WE SHOULD CONSIDER AT
LEAST A MENTION OF LOCALLY HEAVY RAINFALL OVER THE NORTHERN HILL
COUNTRY INTO THE NORTHERN PART OF AUSTIN METRO FOR TODAY. SHOULD
THE HRRR CONTINUE TO ADVERTISE ROBUST STORM DEVELOPMENT FURTHER
DOWN THE I-35 CORRIDOR...WE MAY CONSIDER A RAISE OF POPS AND
EXPANSION OF THE HEAVY RAINFALL MENTION. OTHER HI-RES MODELS SHOW
POOR AGREEMENT ON THESE SHORT-TERM TRENDS...SO WITH LOW CONFIDENCE
WILL NOT EXPRESS A CONCERN OVER THE SATURATED SOILS OR THE NEED
FOR A FFA AT THIS TIME.

ASIDE FROM THE ACTIVITY AFFECTING NORTHERN COUNTIES TODAY...OVERALL
MODEL TRENDS HAVE BEEN CONSISTENT FOR A RELATIVELY STABLE FORECAST
FOR OUR SOUTHERN COUNTIES TODAY INTO WEDNESDAY. FORECAST WEAK 700
MB RIDGING SHOULD LEAD TO EVEN LESS CONVECTIVE ACTIVITY FOR
DAYTIME WEDNESDAY THAN TODAY.

LONG TERM (WEDNESDAY NIGHT THROUGH MONDAY)...
THE RECOVERY TIME FOR SOUTH CENTRAL TX SOILS AND RIVERS IS SHORT
AS MODEL CONSENSUS NOW SHOWS GOOD AGREEMENT ON A COLD FRONT FOCUS
FOR MORE CONVECTION WEDNESDAY NIGHT INTO THURSDAY. THE MORE
DISTINCT INDICATION OF THE FRONT WOULD SUGGEST THAT THE FRONT
COULD POSSIBLY REMOVE SOME OF THE LOW LEVEL MOISTURE AND LEAD TO
LIGHTER RAINFALL TOTALS INITIALLY. SOME BRIEF HEAVY DOWNPOURS AND
A FEW STRONG STORMS COULD OCCUR WEDNESDAY EVENING GIVEN THE
EVENING TIMING EXPECTED.

MODELS SHOW HIGHEST QPF CONCENTRATIONS SHIFTING TO WESTERN
COUNTIES BY LATE THURSDAY WHERE ELEVATED MOISTURE POOLING IS
PINNED AGAINST THE HIGHER TERRAIN TO THE WEST. THE WEAK MID-LEVEL
RIDGING IS CLEARS OUT BY THEN...AND OVERRUNNING OF THE UNSTABLE
MOIST AIR SHOULD BE ABLE TO SPREAD EAST ACROSS ALL AREAS THURSDAY
NIGHT INTO FRIDAY WITH MULTIPLE ROUNDS OF ELEVATED STORMS THAT
TRANSITION INTO DEEPER CONVECTION BY FRIDAY. AT SOME POINT A FLASH
FLOOD WATCH WILL PROBABLY BE ISSUED...POSSIBLY AS EARLY AS
THURSDAY NIGHT. THE HEAVIEST RAINFALL CONCERN IS SAVED FOR
MEMORIAL DAY WEEKEND...AND WITH ALL MODELS SHOWING A GOOD PATTERN
FOR A SLOW MOVING COMPLEX ENHANCED BY A HIGH AMPLITUDE UPPER
TROUGH...WILL SHOW MOST OF THE ATTENTION FOR LATE SATURDAY THROUGH
LATE SUNDAY.

&&

.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY              85  71  86  69  81 /  50  20  20  40  30
AUSTIN BERGSTROM INTL AIRPORT  85  71  85  69  82 /  40  20  20  30  40
NEW BRAUNFELS MUNI AIRPORT     85  71  85  70  82 /  30  20  20  30  40
BURNET MUNI AIRPORT            82  70  84  67  78 /  50  30  20  40  30
DEL RIO INTL AIRPORT           87  72  86  70  83 /  30  20  20  50  40
GEORGETOWN MUNI AIRPORT        84  71  84  67  79 /  50  20  20  40  30
HONDO MUNI AIRPORT             86  71  86  71  83 /  30  20  20  40  40
SAN MARCOS MUNI AIRPORT        85  71  85  70  82 /  30  20  20  30  40
LA GRANGE - FAYETTE REGIONAL   85  73  86  71  83 /  30  20  20  20  40
SAN ANTONIO INTL AIRPORT       85  72  86  71  82 /  30  20  20  30  40
STINSON MUNI AIRPORT           87  73  87  72  84 /  30  20  20  30  40

&&

.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

MESOSCALE/AVIATION...TB3
SYNOPTIC/GRIDS...HAMPSHIRE
PUBLIC SERVICE/DATA COLLECTION...TREADWAY




AREA FORECAST DISCUSSION

NWS AUSTIN/SAN ANTONIO TX

 645 AM CDT TUE MAY 19 2015

.DISCUSSION...12Z AVIATION BELOW.

&&

.AVIATION...BKN-OVC MVFR TO IFR CEILINGS WITH STRATUS THIS
MORNING ACROSS SOUTH-CENTRAL TEXAS. REMNANTS OF OVERNIGHT
CONVECTIVE COMPLEX IS PASSING NORTH OF THE CWA THIS MORNING.
A FEW SHRA AND ISOLATED TSTMS POSSIBLE THROUGH THE MORNING ACROSS
THE HILL COUNTRY AND CENTRAL TEXAS NEAR AUS...FEEDING INTO WHAT IS
LEFT OF THE MCV FARTHER TO THE NORTH. OTHERWISE...CEILINGS SLOWLY
RISING AFTER 16Z AND EVENTUALLY BECOMING VFR 18Z-20Z.
MVFR CEILINGS RE-DEVELOPING 03Z-05Z AUS/SAT/SSF AND BECOMING IFR
06Z-08Z. MVFR CEILINGS RE-DEVELOP AT DRT 06Z-08Z.

&&

.PREV DISCUSSION... /ISSUED 357 AM CDT TUE MAY 19 2015/

SHORT TERM (TODAY THROUGH WEDNESDAY)...
A SLOW MOVING MCS OVER WEST CENTRAL TX IS PRODUCING FLASH
FLOODING OVER THE SAN ANGELO AREA EARLY THIS MORNING. IN THE PAST
HOUR OR SO...THE SOUTHERN PORTION OF THE COMPLEX IS TAKING OVER
AND SHOWING A MORE FORWARD PROPAGATING TREND. HI-RES MODEL
SUGGESTED CORFIDI VECTORS SUGGEST THE STORMS TO REMAIN MOSTLY IN
THE FORECAST AREAS TO THE NORTH...BUT AS NOTED IN THE LATEST
SPENES AND FFGMPD DISCUSSIONS...DIFFLUENCE ALOFT IS CAUSING HI-
RES SOLUTIONS TO SLOW DOWN THE MOTION WITH THE SYSTEM EXPECTED
BECOME MORE DISORGANIZED AND SLOWER TOWARD DAYBREAK. UPSHEAR
PROPAGATION VECTORS AND MODEL DEPICTIONS OF AN INCREASING MOISTURE
TAP LATER IN THE MORNING WOULD SUGGEST THAT WE SHOULD CONSIDER AT
LEAST A MENTION OF LOCALLY HEAVY RAINFALL OVER THE NORTHERN HILL
COUNTRY INTO THE NORTHERN PART OF AUSTIN METRO FOR TODAY. SHOULD
THE HRRR CONTINUE TO ADVERTISE ROBUST STORM DEVELOPMENT FURTHER
DOWN THE I-35 CORRIDOR...WE MAY CONSIDER A RAISE OF POPS AND
EXPANSION OF THE HEAVY RAINFALL MENTION. OTHER HI-RES MODELS SHOW
POOR AGREEMENT ON THESE SHORT-TERM TRENDS...SO WITH LOW CONFIDENCE
WILL NOT EXPRESS A CONCERN OVER THE SATURATED SOILS OR THE NEED
FOR A FFA AT THIS TIME.

ASIDE FROM THE ACTIVITY AFFECTING NORTHERN COUNTIES TODAY...OVERALL
MODEL TRENDS HAVE BEEN CONSISTENT FOR A RELATIVELY STABLE FORECAST
FOR OUR SOUTHERN COUNTIES TODAY INTO WEDNESDAY. FORECAST WEAK 700
MB RIDGING SHOULD LEAD TO EVEN LESS CONVECTIVE ACTIVITY FOR
DAYTIME WEDNESDAY THAN TODAY.

LONG TERM (WEDNESDAY NIGHT THROUGH MONDAY)...
THE RECOVERY TIME FOR SOUTH CENTRAL TX SOILS AND RIVERS IS SHORT
AS MODEL CONSENSUS NOW SHOWS GOOD AGREEMENT ON A COLD FRONT FOCUS
FOR MORE CONVECTION WEDNESDAY NIGHT INTO THURSDAY. THE MORE
DISTINCT INDICATION OF THE FRONT WOULD SUGGEST THAT THE FRONT
COULD POSSIBLY REMOVE SOME OF THE LOW LEVEL MOISTURE AND LEAD TO
LIGHTER RAINFALL TOTALS INITIALLY. SOME BRIEF HEAVY DOWNPOURS AND
A FEW STRONG STORMS COULD OCCUR WEDNESDAY EVENING GIVEN THE
EVENING TIMING EXPECTED.

MODELS SHOW HIGHEST QPF CONCENTRATIONS SHIFTING TO WESTERN
COUNTIES BY LATE THURSDAY WHERE ELEVATED MOISTURE POOLING IS
PINNED AGAINST THE HIGHER TERRAIN TO THE WEST. THE WEAK MID-LEVEL
RIDGING IS CLEARS OUT BY THEN...AND OVERRUNNING OF THE UNSTABLE
MOIST AIR SHOULD BE ABLE TO SPREAD EAST ACROSS ALL AREAS THURSDAY
NIGHT INTO FRIDAY WITH MULTIPLE ROUNDS OF ELEVATED STORMS THAT
TRANSITION INTO DEEPER CONVECTION BY FRIDAY. AT SOME POINT A FLASH
FLOOD WATCH WILL PROBABLY BE ISSUED...POSSIBLY AS EARLY AS
THURSDAY NIGHT. THE HEAVIEST RAINFALL CONCERN IS SAVED FOR
MEMORIAL DAY WEEKEND...AND WITH ALL MODELS SHOWING A GOOD PATTERN
FOR A SLOW MOVING COMPLEX ENHANCED BY A HIGH AMPLITUDE UPPER
TROUGH...WILL SHOW MOST OF THE ATTENTION FOR LATE SATURDAY THROUGH
LATE SUNDAY.

&&

.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY              85  71  86  69  81 /  40  20  20  40  30
AUSTIN BERGSTROM INTL AIRPORT  85  71  85  69  82 /  30  20  20  30  40
NEW BRAUNFELS MUNI AIRPORT     85  71  85  70  82 /  20  20  20  30  40
BURNET MUNI AIRPORT            82  70  84  67  78 /  40  30  20  40  30
DEL RIO INTL AIRPORT           87  72  86  70  83 /  30  20  20  50  40
GEORGETOWN MUNI AIRPORT        84  71  84  67  79 /  40  20  20  40  30
HONDO MUNI AIRPORT             86  71  86  71  83 /  30  20  20  40  40
SAN MARCOS MUNI AIRPORT        85  71  85  70  82 /  30  20  20  30  40
LA GRANGE - FAYETTE REGIONAL   85  73  86  71  83 /  30  20  20  20  40
SAN ANTONIO INTL AIRPORT       85  72  86  71  82 /  30  20  20  30  40
STINSON MUNI AIRPORT           87  73  87  72  84 /  20  20  20  30  40

&&

.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

MESOSCALE/AVIATION...76
SYNOPTIC/GRIDS...18




AREA FORECAST DISCUSSION

NWS SACRAMENTO CA

 328 PM PDT Tue May 19 2015

.Synopsis...
Variable clouds and mainly mountain showers and afternoon
thunderstorms through the week as a series of weak low pressure
systems move across California. Daytime highs forecast to remain
below normal.

&&

.Discussion...
Broad upper low is over California and will only gradually shift
east into the weekend. Not as much activity as shown by short
range models thus far this afternoon over the mountains. The best
coverage is over the coastal range...not much at all over the
Sierra. HRRR model shows best activity over the coastal range and
the Sierra south of Kirkwood through the evening. WRF core model
indicates more mountain shower and thunderstorm activity Wednesday
and Thursday with possibly an isolated cell or two in valley.
Weak/moderate onshore flow will keep temperatures slightly below
normal srn sac/nrn sj valleys into the weekend.

&&

.Extended Discussion (Saturday through Tuesday)

Area will be sandwiched between ridging building over eastern
Pacific and trough departing to the east for the start of the weekend.
Models continue to differ on the track and speed of the trough as
it departs. GFS moves the trough off faster to the east with
riding across the area for the weekend into Tuesday, which would
lead to a dry forecast. ECMWF/GEM are slower with the departure
and continue the chance for mountain showers and thunderstorms
through at least Sunday. Given uncertainty, have not made major
changes to going forecast. Feel that there may be enough
instability present to continue the chance for daily showers and
thunderstorms across higher terrain through Sunday for now. May
then see a break in convection for Monday and Tuesday. Regardless,
valley should remain dry in either scenario. Temperatures will
hover within a few degrees of normal with valley highs generally
in the 80s and foothills/mountains in the 50s to 60s. CEO


&&

.Aviation...

Mainly VFR conditions for interior NorCal except during showers
and afternoon/evening thunderstorms that bring periods of MVFR.
Best chance for showers/thunderstorms is across higher terrain and far
northern portions of Sacramento valley. The onshore flow will
bring light winds to TAF sites around 5-12 kts. Delta breeze will
be 10-20 kts with gusts up to 25 kts.


&&

.STO Watches/Warnings/Advisories...
None.
&&

$$







AREA FORECAST DISCUSSION

NWS NEW YORK NY

 431 PM EDT TUE MAY 19 2015

.SYNOPSIS...
A COLD FRONT CROSSES THE REGION TONIGHT. THE FRONT STALLS TO THE
SOUTH INTO THURSDAY AS HIGH PRESSURE BUILDS IN FROM THE WEST
THROUGH THURSDAY. LOW PRESSURE PASSES TO THE SOUTHEAST THURSDAY
NIGHT INTO FRIDAY MORNING...THEN A WEAK COLD FRONT MOVES THROUGH
FRIDAY AFTERNOON INTO EVENING. HIGH PRESSURE THEN CONTROLS THE
WEATHER THROUGH SUNDAY...FOLLOWED BY AN APPROACHING WARM FRONT ON
MONDAY. THIS BOUNDARY THEN STALLS NEAR THE AREA INTO TUESDAY.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
SURFACE WARM FRONT STILL EDGING EASTWARD...BASICALLY TO NEAR THE
HUDSON RIVER AT 19Z...AND INCHING EAST. COLD FRONT IS FAST ON ITS
HEELS FROM EASTERN UPSTATE NEW YORK BACK INTO NE PA. MAIN QUESTION
IS HOW MUCH CONVECTION THAT FIRES ALONG THE FRONT OVER THE
CATSKILLS/POCONOS HOLDS TOGETHER IS IT TRACKS SE INTO THE CWA. NAM
IS MOST AGGRESSIVE...AND APPEARS ON OUTLIER. OTHER HI-RES MODELS
INCLUDING RAP AND HRRR AS WELL AS SREF SUGGESTS LITTLE IF
ANYTHING HOLD TOGETHER EAST OF THE HUDSON. POPS ARE WEIGHED
TOWARDS THIS CONSENSUS.

RAP SHOWING POTENTIAL FOR AROUND 1000 J/KG CAPE OVER THE LOWER
HUDSON VALLEY/NE NJ SO POTENTIAL FOR SOME LOCALLY STRONG STORMS
THERE...WITH LOCALLY HEAVY RAINFALL AS WELL NOTING PRECIPITABLE
WATERS TO AROUND 1.5 INCHES JUST AHEAD OF THE FRONT. COULD ALSO
SEE A FEW HUNDRED J/KG OF CAPE INTO INTERIOR SW CT ZONES...SO DO
HAVE CHANCE THUNDER IN FOR NE NJ/LOWER HUDSON VALLEY/SW CT AHEAD
OF THE FRONT.

SHOULD CLEAR OUT FAIRLY QUICKLY BEHIND THE FRONT...WITH 20-25KT
DOWNSLOPING BL WINDS. SO COULD SEE GUSTS TO AROUND 20 TO MAYBE
OCCASIONALLY 25 MPH BY MORNING.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
MAINLY ZONAL FLOW ALOFT WEDNESDAY-WEDNESDAY NIGHT...AND WITH BEST
FORCING WITH A PASSING N STREAM SHORT WAVE STAYING WELL TO THE
N...WENT WITH A DRY FORECAST IN THIS TIME FRAME.

GUSTY WINDS SHOULD CONTINUE THROUGH THE MORNING...THEN DIMINISH
INTO THE AFTERNOON AS LOW LEVEL WINDS REDUCE DOWN TO 15-20KT BY
MID TO LATE AFTERNOON. WINDS CONTINUE TO DIMINISH WEDNESDAY
NIGHT...WHICH COUPLED WITH MINIMAL CLOUD COVER SHOULD PROMOTE
SOLID RADIATIONAL COOLING.

FOR HIGHS WEDNESDAY USED A BLEND OF MIXING DOWN FROM 875-850 HPA
PER BUFKIT SOUNDINGS WITH NAM 2-METER TEMPERATURES AND A BLEND OF
MAV/MET/ECS GUIDANCE. HIGHS SHOULD BE A FEW DEGREES BELOW NORMAL.

FOR LOWS WEDNESDAY NIGHT...A BLEND OF ECS/MAV/MET GUIDANCE WAS
USED...TWEAKED DOWN SLIGHTLY OVER NORMALLY COLDER LOCATIONS. LOWS
SHOULD BE AROUND 5-10 DEGREES BELOW NORMAL.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
MOST OF THE GUIDANCE KEEPS THE DAYTIME HOURS OF THURSDAY DRY WITH
HIGH PRESSURE BEING THE MAIN INFLUENCE. AT THE LEAST...BROKEN TO
OVERCAST MID TO HIGH LEVEL CLOUDS DEVELOP. SO PARTLY SUNNY TO MOSTLY
CLOUDY. A BLEND OF MAV/NAM MOS LOOKED REASONABLE FOR HIGH
TEMPERATURES.

HAVE INSERTED SLIGHT CHANCE POPS FOR THURSDAY NIGHT FOR THE
SOUTHERN ZONES AS LOW PRESSURE PASSES TO THE SOUTHEAST...BRINGING
THE NORTHERN FRINGE OF THE PRECIPITATION SHIELD TO THIS PART OF
THE CWA. A COLD FRONT THEN FOLLOWS FRIDAY AFTERNOON INTO EVENING.
MOISTURE IS LACKING...BUT AN ISOLATED SHOWER IS NOT OUT OF THE
QUESTION. WILL HOWEVER MAINTAIN A DRY FORECAST FOR NOW. HIGHS FOR
FRIDAY SLIGHTLY ABOVE NORMAL.

HIGH PRESSURE IS THEN RESTORED FOR THE WEEKEND WITH DRY WEATHER
HIGHS SATURDAY IN THE MID-UPPER 60S...THEN WARMING INTO THE LOW-MID
70S ON SUNDAY AS WINDS SHIFT SW.

A WARM FRONT APPROACHES FROM THE SW LATE SUNDAY NIGHT. MEANWHILE...A
COLD FRONT DROPS DOWN FROM THE NORTH. SOME UNCERTAINTY REGARDING HOW
FAR SOUTH IT PUSHES. GIVEN MODEL AGREEMENT OF UPPER RIDGING...WILL
FAVOR THE IDEA THAT THE COLD FRONT REMAINS TO THE NORTH...OR AT MOST
PASSES THROUGH PART OF THE CWA BEFORE RETREATING BACK NORTH. IN ANY
CASE...WILL CARRY CHANCE POPS LATE SUN NIGHT THROUGH TUESDAY WITH
BOTH FRONTS NEARBY. A RUMBLE OF THUNDER ALSO POSSIBLE WITH SOME
CAPE PRESENT AFTER SUNDAY NIGHT.

&&

.AVIATION /21Z TUESDAY THROUGH SUNDAY/...
A COLD FRONT ACROSS UPSTATE NY WILL PASS THRU THE REGION TONIGHT.

MAINLY VFR THRU 00Z...ESPECIALLY THE METRO. TSTMS APPEAR THEY WILL
REMAIN RELEGATED TO AREAS NW OF THE CITY THIS EVE. VCTS INCLUDED FOR
KSWF...OTHERWISE NO TSTMS FORECAST ELSEWHERE. THERE IS A LOW PROB
THAT TSTMS HOLD TOGETHER TO IMPACT THE METRO. MOST LIKELY SCENARIO
IS SCT -RA. VFR BEHIND THE COLD FRONT TONIGHT.

LIGHT SW WIND THIS EVE...WITH COMPLICATED MARINE INFLUENCED FLOW
AT THE COASTAL TERMINALS. WINDS BECOME NW BEHIND THE FRONT...WITH
SPEEDS GENERALLY 15-25 KT THRU THE REMAINDER OF THE TAF PERIOD.

     NY METRO ENHANCED AVIATION WEATHER SUPPORT...

DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS
CAN BE FOUND AT:
HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)

KJFK FCSTER COMMENTS: SOME VARIABILITY IN WIND DIRECTION POSSIBLE
THRU 4Z. LOW CHANCE FOR MVFR CIGS 00Z TO 04Z.

KLGA FCSTER COMMENTS: SOME VARIABILITY IN WIND DIRECTION POSSIBLE
THEREAFTER THRU 4Z. LOW CHANCE FOR MVFR CIGS 00Z TO 04Z.

KEWR FCSTER COMMENTS: SIGNIFICANT CHANGES TO WIND DIRECTION THRU
3Z MAY BE NEEDED IF SEA BREEZE FLOW DEVELOPS...BRINGING WINDS TO
AROUND 140 TRUE. LOW PROB OF RESIDUAL TSTMS REACHING THE TERMINAL
AFT 00Z.

KTEB FCSTER COMMENTS: LOW PROB OF RESIDUAL TSTMS REACHING THE
TERMINAL AFT 00Z.

KHPN FCSTER COMMENTS: LOW PROB OF RESIDUAL TSTMS REACHING THE
TERMINAL AFT 00Z.

KISP FCSTER COMMENTS: CONDITIONS MAY REMAIN VFR TIL AROUND 00Z.

.OUTLOOK FOR 18Z WEDNESDAY THROUGH SATURDAY...
.WED...VFR. NW WINDS 15-25KT.
.THU...VFR WITH SW WINDS.
.FRI...VFR WITH W FLOW BECOMING NW.
.SAT...VFR WITH VRB WINDS.
.SUN...VFR WITH SW WINDS.

&&

.MARINE...
WINDS INCREASE THIS EVENING BEHIND A COLD FRONT...AND REMAIN GUSTY
TO AROUND 20 KT...WITH OCCASIONAL GUSTS TO AROUND 25 KT NEAR
SHORE IN THE NY BIGHT REGION...INTO WEDNESDAY EVENING...BEFORE
SUBSIDING LATER WEDNESDAY NIGHT. FOR NOW EXPECT CONDITIONS TO
STAY JUST BELOW SCA LEVELS...HOWEVER CANNOT COMPLETELY RULE OUT A
FEW HOURS OF GUSTS TO AROUND 25 KT NEAR SHORE AROUND NYC/WESTERN
LONG ISLAND WEDNESDAY MORNING.

SEAS ARE EXPECTED TO REMAIN BELOW 5 FT THROUGH THE REST OF THE
FORECAST PERIOD. THERE COULD BE HOWEVER BE FREQUENT GUSTS TO SCA
CRITERIA FRIDAY AFTERNOON AND EVENING BEHIND A COLD FRONT.

&&

.FIRE WEATHER...
WINDS WILL GUSTS TO AROUND 20 TO OCCASIONALLY 25 MPH WEDNESDAY
MORNING...THEN GUSTS SHOULD SLACKEN IN THE AFTERNOON. MINIMUM
RELATIVE HUMIDITIES ARE GENERALLY FORECAST TO BE 30-25
PERCENT...EXCEPT 25-30 PERCENT IN THE IMMEDIATE NYC METRO. GIVEN
THE UNCERTAINTY...PLUS UNCERTAINTY ON HOW MUCH RAINFALL WILL BE
RECEIVED THIS EVENING. WILL HOLD OFF ON ISSUING ANY FIRE WEATHER
RELATED PRODUCTS FOR WEDNESDAY AT THIS TIME.

&&

.HYDROLOGY...
GENERALLY LESS THAN .2 INCHES OF RAIN IS EXPECTED THROUGH THIS
EVENING. HOWEVER...ANY STRONGER CONVECTION WHICH DOES OCCUR OVER
MAINLY NE NJ/LOWER HUDSON VALLEY/SW CT COULD PRODUCE LOCALLY HEAVY
RAINFALL. IF THIS WERE TO OCCUR...THEN THE PONDING OF WATER ON
ROADWAYS WOULD BE POSSIBLE.

NO SIGNIFICANT PRECIPITATION AMOUNTS ARE EXPECTED FROM LATE
TONIGHT THROUGH SUNDAY.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...JC/MALOIT
NEAR TERM...MALOIT
SHORT TERM...MALOIT
LONG TERM...JC
AVIATION...JMC/DS
MARINE...JC/MALOIT
FIRE WEATHER...
HYDROLOGY...JC/MALOIT




AREA FORECAST DISCUSSION

NWS NEW YORK NY

 343 PM EDT TUE MAY 19 2015

.SYNOPSIS...
A COLD FRONT CROSSING THE REGION TONIGHT. THE FRONT STALLS TO THE
SOUTH INTO THURSDAY AS HIGH PRESSURE BUILDS IN FROM THE WEST
THROUGH THURSDAY. LOW PRESSURE PASSES TO THE SOUTHEAST THURSDAY
NIGHT INTO FRIDAY MORNING...THEN A WEAK COLD FRONT MOVES THROUGH
FRIDAY AFTERNOON INTO EVENING. HIGH PRESSURE THEN CONTROLS THE
WEATHER THROUGH SUNDAY...FOLLOWED BY AN APPROACHING WARM FRONT ON
MONDAY. THIS BOUNDARY THEN STALLS NEAR THE AREA INTO TUESDAY.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
SURFACE WARM FRONT STILL EDGING EASTWARD...BASICALLY TO NEAR THE
HUDSON RIVER AT 19Z...AND INCHING EAST. COLD FRONT IS FAST ON ITS
HEELS FROM EASTERN UPSTATE NEW YORK BACK INTO NE PA. MAIN QUESTION
IS HOW MUCH CONVECTION THAT FIRES ALONG THE FRONT OVER THE
CATSKILLS/POCONOS HOLDS TOGETHER IS IT TRACKS SE INTO THE CWA. NAM
IS MOST AGGRESSIVE...AND APPEARS ON OUTLIER. OTHER HI-RES MODELS
INCLUDING RAP AND HRRR AS WELL AS SREF SUGGESTS LITTLE IF
ANYTHING HOLD TOGETHER EAST OF THE HUDSON. POPS ARE WEIGHED
TOWARDS THIS CONSENSUS.

RAP SHOWING POTENTIAL FOR AROUND 1000 J/KG CAPE OVER THE LOWER
HUDSON VALLEY/NE NJ SO POTENTIAL FOR SOME LOCALLY STRONG STORMS
THERE...WITH LOCALLY HEAVY RAINFALL AS WELL NOTING PRECIPITABLE
WATERS TO AROUND 1.5 INCHES JUST AHEAD OF THE FRONT. COULD ALSO
SEE A FEW HUNDRED J/KG OF CAPE INTO INTERIOR SW CT ZONES...SO DO
HAVE CHANCE THUNDER IN FOR NE NJ/LOWER HUDSON VALLEY/SW CT AHEAD
OF THE FRONT.

SHOULD CLEAR OUT FAIRLY QUICKLY BEHIND THE FRONT...WITH 20-25KT
DOWNSLOPING BL WINDS. SO COULD SEE GUSTS TO AROUND 20 TO MAYBE
OCCASIONALLY 25 MPH BY MORNING.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
MAINLY ZONAL FLOW ALOFT WEDNESDAY-WEDNESDAY NIGHT...AND WITH BEST
FORCING WITH A PASSING N STREAM SHORT WAVE STAYING WELL TO THE
N...WENT WITH A DRY FORECAST IN THIS TIME FRAME.

GUSTY WINDS SHOULD CONTINUE THROUGH THE MORNING...THEN DIMINISH
INTO THE AFTERNOON AS LOW LEVEL WINDS REDUCE DOWN TO 15-20KT BY
MID TO LATE AFTERNOON. WINDS CONTINUE TO DIMINISH WEDNESDAY
NIGHT...WHICH COUPLED WITH MINIMAL CLOUD COVER SHOULD PROMOTE
SOLID RADIATIONAL COOLING.

FOR HIGHS WEDNESDAY USED A BLEND OF MIXING DOWN FROM 875-850 HPA
PER BUFKIT SOUNDINGS WITH NAM 2-METER TEMPERATURES AND A BLEND OF
MAV/MET/ECS GUIDANCE. HIGHS SHOULD BE A FEW DEGREES BELOW NORMAL.

FOR LOWS WEDNESDAY NIGHT...A BLEND OF ECS/MAV/MET GUIDANCE WAS
USED...TWEAKED DOWN SLIGHTLY OVER NORMALLY COLDER LOCATIONS. LOWS
SHOULD BE AROUND 5-10 DEGREES BELOW NORMAL.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
MOST OF THE GUIDANCE KEEPS THE DAYTIME HOURS OF THURSDAY DRY WITH
HIGH PRESSURE BEING THE MAIN INFLUENCE. AT THE LEAST...BROKEN TO
OVERCAST MID TO HIGH LEVEL CLOUDS DEVELOP. SO PARTLY SUNNY TO MOSTLY
CLOUDY. A BLEND OF MAV/NAM MOS LOOKED REASONABLE FOR HIGH
TEMPERATURES.

HAVE INSERTED SLIGHT CHANCE POPS FOR THURSDAY NIGHT FOR THE
SOUTHERN ZONES AS LOW PRESSURE PASSES TO THE SOUTHEAST...BRINGING
THE NORTHERN FRINGE OF THE PRECIPITATION SHIELD TO THIS PART OF
THE CWA. A COLD FRONT THEN FOLLOWS FRIDAY AFTERNOON INTO EVENING.
MOISTURE IS LACKING...BUT AN ISOLATED SHOWER IS NOT OUT OF THE
QUESTION. WILL HOWEVER MAINTAIN A DRY FORECAST FOR NOW. HIGHS FOR
FRIDAY SLIGHTLY ABOVE NORMAL.

HIGH PRESSURE IS THEN RESTORED FOR THE WEEKEND WITH DRY WEATHER
HIGHS SATURDAY IN THE MID-UPPER 60S...THEN WARMING INTO THE LOW-MID
70S ON SUNDAY AS WINDS SHIFT SW.

A WARM FRONT APPROACHES FROM THE SW LATE SUNDAY NIGHT. MEANWHILE...A
COLD FRONT DROPS DOWN FROM THE NORTH. SOME UNCERTAINTY REGARDING HOW
FAR SOUTH IT PUSHES. GIVEN MODEL AGREEMENT OF UPPER RIDGING...WILL
FAVOR THE IDEA THAT THE COLD FRONT REMAINS TO THE NORTH...OR AT MOST
PASSES THROUGH PART OF THE CWA BEFORE RETREATING BACK NORTH. IN ANY
CASE...WILL CARRY CHANCE POPS LATE SUN NIGHT THROUGH TUESDAY WITH
BOTH FRONTS NEARBY. A RUMBLE OF THUNDER ALSO POSSIBLE WITH SOME
CAPE PRESENT AFTER SUNDAY NIGHT.

&&

.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
A COLD FRONT ACROSS UPSTATE NY WILL PASS THRU THE REGION TONIGHT.

MAINLY VFR THRU 00Z...ESPECIALLY THE METRO. TSTMS APPEAR THEY WILL
REMAIN RELEGATED TO AREAS NW OF THE CITY THIS EVE. VCTS INCLUDED FOR
KSWF...OTHERWISE NO TSTMS FORECAST ELSEWHERE. THERE IS A LOW PROB
THAT TSTMS HOLD TOGETHER TO IMPACT THE METRO. MOST LIKELY SCENARIO
IS REMNANT MVFR CIGS AND PERHAPS SOME -RA. VFR BEHIND THE COLD
FRONT TONIGHT.

LIGHT SW WIND THIS EVE...WITH COMPLICATED MARINE INFLUENCED FLOW
AT THE COASTAL TERMINALS. WINDS BECOME NW BEHIND THE FRONT...WITH
SPEEDS GENERALLY 15-25 KT THRU THE REMAINDER OF THE TAF PERIOD.

...NY METRO ENHANCED AVIATION WEATHER SUPPORT...

DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS
CAN BE FOUND AT:
HTTP://WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)

KJFK FCSTER COMMENTS: SOME VARIABILITY IN WIND DIRECTION POSSIBLE
THRU 4Z.

KLGA FCSTER COMMENTS: WINDS MAY REMAIN FROM THE NE BEYOND 20Z. SOME
VARIABILITY IN WIND DIRECTION POSSIBLE THEREAFTER THRU 4Z.

KEWR FCSTER COMMENTS: SIGNIFICANT CHANGES TO WIND DIRECTION THRU
3Z MAY BE NEEDED IF SEA BREEZE FLOW DEVELOPS...BRINGING WINDS TO
AROUND 140 TRUE. LOW PROB OF RESIDUAL TSTMS REACHING THE TERMINAL
AFT 00Z.

KTEB FCSTER COMMENTS: LOW PROB OF RESIDUAL TSTMS REACHING THE
TERMINAL AFT 00Z.

KHPN FCSTER COMMENTS: LOW PROB OF RESIDUAL TSTMS REACHING THE
TERMINAL AFT 00Z.

KISP FCSTER COMMENTS: CONDITIONS MAY REMAIN VFR TIL AROUND 00Z.

.OUTLOOK FOR 18Z WEDNESDAY THROUGH SATURDAY...
.WED...VFR. NW WINDS 15-25KT.
.THU...VFR WITH SW WINDS.
.FRI...VFR WITH W FLOW BECOMING NW.
.SAT...VFR WITH VRB WINDS.
.SUN...VFR WITH SW WINDS.

&&

.MARINE...
WINDS INCREASE THIS EVENING BEHIND A COLD FRONT...AND REMAIN GUSTY
TO AROUND 20 KT...WITH OCCASIONAL GUSTS TO AROUND 25 KT NEAR
SHORE IN THE NY BIGHT REGION...INTO WEDNESDAY EVENING...BEFORE
SUBSIDING LATER WEDNESDAY NIGHT. FOR NOW EXPECT CONDITIONS TO
STAY JUST BELOW SCA LEVELS...HOWEVER CANNOT COMPLETELY RULE OUT A
FEW HOURS OF GUSTS TO AROUND 25 KT NEAR SHORE AROUND NYC/WESTERN
LONG ISLAND WEDNESDAY MORNING.

&&

.FIRE WEATHER...
WINDS WILL GUSTS TO AROUND 20 TO OCCASIONALLY 25 MPH WEDNESDAY
MORNING...THEN GUSTS SHOULD SLACKEN IN THE AFTERNOON. MINIMUM
RELATIVE HUMIDITIES ARE GENERALLY FORECAST TO BE 30-25
PERCENT...EXCEPT 25-30 PERCENT IN THE IMMEDIATE NYC METRO. GIVEN
THE UNCERTAINTY...PLUS UNCERTAINTY ON HOW MUCH RAINFALL WILL BE
RECEIVED THIS EVENING. WILL HOLD OFF ON ISSUING ANY FIRE WEATHER
RELATED PRODUCTS FOR WEDNESDAY AT THIS TIME.

&&

.HYDROLOGY...
GENERALLY LESS THAN .2 INCHES OF RAIN IS EXPECTED THROUGH THIS
EVENING. HOWEVER...ANY STRONGER CONVECTION WHICH DOES OCCUR OVER
MAINLY NE NJ/LOWER HUDSON VALLEY/SW CT COULD PRODUCE LOCALLY HEAVY
RAINFALL. IF THIS WERE TO OCCUR...THEN THE PONDING OF WATER ON
ROADWAYS WOULD BE POSSIBLE.

NO SIGNIFICANT PRECIPITATION AMOUNTS ARE EXPECTED FROM LATE
TONIGHT THROUGH SUNDAY.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.

&&

$$

SYNOPSIS...JC/MALOIT
NEAR TERM...MALOIT
SHORT TERM...MALOIT
LONG TERM...JC
AVIATION...JMC
MARINE...JC/MALOIT
FIRE WEATHER...
HYDROLOGY...JC/MALOIT



AREA FORECAST DISCUSSION

NWS MOUNT HOLLY NJ

 352 PM EDT TUE MAY 19 2015

.SYNOPSIS...
A COLD FRONT APPROACHING FROM THE WEST WILL PASS THROUGH OUR
REGION EARLY TONIGHT. HIGH PRESSURE IS FORECAST TO FOLLOW FOR
WEDNESDAY INTO WEDNESDAY NIGHT. WEAK LOW PRESSURE IS EXPECTED TO
BE LOCATED OVER NORTH CAROLINA ON THURSDAY BEFORE IT MOVES OUT TO
SEA ON THURSDAY NIGHT. A COLD FRONT FROM THE NORTHWEST IS
ANTICIPATED TO ARRIVE ON FRIDAY EVENING WITH HIGH PRESSURE
FORECAST TO BUILD ACROSS OUR REGION IN ITS WAKE FOR SATURDAY. A
WARM FRONT IS EXPECTED TO APPROACH FROM THE SOUTHWEST ON SUNDAY
AND MONDAY, AS A COLD FRONT PUSHES DOWN FROM THE NORTH AND
NORTHEAST. ANOTHER FRONTAL BOUNDARY MAY MOVE TOWARD OUR REGION
FROM THE NORTHWEST ON TUESDAY.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
THE COLD FRONT WILL MOVE THROUGH THE CWA THIS EVENING AND BRING A
SMALL CHANCE OF SHOWERS AND THUNDERSTORMS. THE HRRR CONTINUES TO
HIT THINGS TOO HARD. WE HAVE NOTHING HIGHER THAN CHANCE.

NORTHWEST WINDS WILL WORK INTO THE REGION BEHIND THE COLD FRONT.
WHILE WE COULD SEE SOME GUSTS OVERNIGHT, IN GENERAL, SPEEDS SHOULD
REMAIN RIGHT AROUND 10 MPH.

OVERNIGHT LOWS WILL DROP INTO THE MID TO UPPER 40S ACROSS THE FAR
NORTHWEST AND INTO THE 50S ELSEWHERE. THE EXCEPTION MIGHT BE
SOUTHERN DELAWARE WHERE A LOW OF 60 IS POSSIBLE. THESE TEMPS
AREN`T TOO FAR FROM NORMAL.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/...
FOR TOMORROW, LOOKS LIKE LOTS OF SUNSHINE WITH BROAD SURFACE HIGH
PRESSURE NOSING IN FROM THE WEST. TEMPS WILL BE COOLER THAN WHAT
WE`RE SEEING TODAY AND SHOULD TOP OUT RIGHT AROUND 60 ACROSS THE
FAR NORTHWEST, IN THE 60S ACROSS THE LEHIGH VALLEY AND NORTHERN
COASTAL PLAIN , AND IN THE 70S ELSEWHERE. HUMIDITY LEVELS WILL BE
LOW. IT WILL BE BREEZY WITH NORTHWEST WIND GUSTS REACHING 20 TO 25
MPH.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
HIGH PRESSURE IS FORECAST TO CONTINUE INFLUENCING OUR WEATHER
INTO WEDNESDAY NIGHT. HOWEVER, HIGH AND MID LEVEL CLOUDS WILL BE
ON THE INCREASE, ESPECIALLY AFTER MIDNIGHT. LOW TEMPERATURES ARE
ANTICIPATED TO BE MAINLY IN THE 40S AND LOWER 50S IN OUR REGION
WITH A FEW READINGS IN THE UPPER 30S IN THE FAR NORTH.

THE MODEL GUIDANCE IS COMING INTO BETTER AGREEMENT REGARDING
THURSDAY`S WEAK LOW IN NORTH CAROLINA AND ITS IMPACTS ON OUR
WEATHER. IT APPEARS AS THOUGH MID LEVEL CLOUDS WILL BE OVERHEAD
FOR MUCH OF THURSDAY INTO THURSDAY EVENING. A DECK OF
STRATOCUMULUS IS ANTICIPATED TO EXPAND OVER OUR SOUTHERN COUNTIES
ON THURSDAY BEFORE CLEARING GRADUALLY FROM THE NORTHWEST ON
THURSDAY NIGHT. ALSO, RAIN IS ANTICIPATED TO AFFECT NORTHEASTERN
MARYLAND, DELAWARE AND SOUTHERN NEW JERSEY. THE FORECAST IMPACTS
ON THE NORTHERN EDGE OF THE SYSTEM MAY SHIFT A LITTLE AS WE GET
CLOSER TO THE EVENT.

A MID LEVEL SHORT WAVE TROUGH IS FORECAST TO APPROACH FROM THE
WEST ON THURSDAY NIGHT AND IT SHOULD PASS OVERHEAD EARLY ON
FRIDAY. A SECOND SHORT WAVE IS EXPECTED ON FRIDAY NIGHT. IT SHOULD
BE PRECEDED BY A COLD FRONTAL PASSAGE IN OUR REGION ON FRIDAY
EVENING. THE SYSTEM SHOULD NOT HAVE MUCH MOISTURE ASSOCIATED WITH
IT, SO WE WILL FORECAST FEW CLOUDS AND NO RAINFALL.

SURFACE HIGH PRESSURE WILL BUILD INTO OUR REGION ON FRIDAY NIGHT
AND SATURDAY. THE CENTER OF THE HIGH IS EXPECTED TO PASS OFF THE
COAST LATE ON SATURDAY. THE AIR MASS SHOULD BRING OUR FORECAST
AREA DRY WEATHER CONDITIONS ALONG WITH SLIGHTLY BELOW NORMAL
TEMPERATURES.

WARMTH AND MOISTURE WILL LIKELY BE ON THE INCREASE ON THE BACK
SIDE OF THE HIGH AS WE GET INTO SUNDAY AND MONDAY. MEANWHILE, A
BACK DOOR COLD FRONT MAY PUSH DOWN FROM THE NORTH AND NORTHEAST ON
SUNDAY NIGHT AND MONDAY. WE ARE ANTICIPATING AN INCREASE IN CLOUD
COVER FROM THE SOUTHWEST IN THE DEVELOPING ISENTROPIC LIFT. ALSO,
THERE MAY BE SOME STRATUS IN THE WAKE OF THE BACK DOOR COLD FRONT.
THE TIMING AND PROGRESSION OF BOTH BOUNDARIES REMAINS A LOW
CONFIDENCE FORECAST AT THIS POINT, FIVE AND SIX DAYS REMOVED.
HOWEVER, WE WILL INDICATE THE INCREASE IN CLOUD COVER ALONG WITH A
CHANCE OF SHOWERS ON SUNDAY NIGHT AND MONDAY MORNING, AND A CHANCE
OF SHOWERS AND THUNDERSTORMS ON MONDAY AFTERNOON.

THE AXIS OF A MID LEVEL RIDGE IS FORECAST TO PASS OVERHEAD ON
MONDAY NIGHT. ANOTHER FRONTAL BOUNDARY MAY APPROACH FROM THE
NORTHWEST ON TUESDAY, SO WE WILL CONTINUE TO MENTION THE POTENTIAL
FOR SOME CLOUDS AND A CHANCE OF SHOWERS AND AFTERNOON
THUNDERSTORMS.

&&

.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.

FINALLY TRANSITIONING TO VFR AND GETTING RID OF THE MARINE LAYER
WITH THE SW TO W WINDS. THE COLD FRONT WILL COME THROUGH THIS
EVENING. THE HRRR HI-RES MODELS CONTINUE TO SHOW SOME SHOWERS AND
THUNDERSTORMS MOVING THROUGH WITH THE FRONT. THE TAFS HAVE A
MENTION BETWEEN 21Z-24ZZ. ANY PRECIPITATION WILL BE SCATTERED AT
BEST. AFTER THE COLD FRONT PASSES, ALL TERMINALS WILL SEE VFR
CONDITIONS OVERNIGHT WITH WEST TO NORTHWEST WINDS AROUND 10 KT.
VFR CONDITIONS WILL REMAIN IN PLACE THROUGH TOMORROW, BUT
NORTHWEST WINDS WILL GUST UP TO 25 KT.

OUTLOOK...
WEDNESDAY NIGHT...MAINLY VFR.

THURSDAY AND THURSDAY NIGHT...MAINLY VFR. A CHANCE OF RAIN FROM
KILG, KMIV AND KACY SOUTHWARD.

FRIDAY THROUGH SUNDAY...MAINLY VFR.

&&

.MARINE...
FOR TONIGHT, THE COLD FRONT PASSES THROUGH IN THE EVENING.
NORTHWEST WINDS WILL INCREASE BEHIND THE FRONT. GUSTS SHOULD
SETTLE RIGHT AROUND 20 KT. GUSTS COULD REACH 25 KT. MODELS PEG THE
NORTHERN WATERS AFTER 3 AM. SEAS SHOULD BE NO WORSE THAN 4 FEET.
ISOLATED SHOWERS AND THUNDERSTORMS ARE EXPECTED WITH THE FRONTAL
PASSAGE.

FOR TOMORROW, HIGH PRESSURE BUILDS IN ACROSS AREA WATERS.
NORTHWEST WINDS WILL REMAIN. THOSE ISOLATED 25 KT GUSTS COULD
PERSIST THROUGH ABOUT 9 AM, OTHERWISE EXPECT 10 TO 15 KT. SEAS
WILL BE IN THE 2 TO 4 FOOT RANGE.

OUTLOOK...
WEDNESDAY NIGHT THROUGH SUNDAY...NO MARINE HEADLINES ARE
ANTICIPATED.

&&

.FIRE WEATHER...
FOR TOMORROW, WE`LL SEE WINDS GUSTING TO 25 MPH AND DRY FINE
FUELS ACROSS PORTIONS OF THE REGION, BUT MINIMUM RH`S ARE FORECAST
TO BE IN THE 30-40% RANGE.

ALSO, WIND GUSTS MAY BE AROUND 20 MPH FROM THE NORTHWEST ON
FRIDAY AFTERNOON. RELATIVE HUMIDITY VALUES MAY FALL INTO THE 30 TO
35 PERCENT RANGE AT THAT TIME IN MUCH OF OUR REGION.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.

&&

$$

SYNOPSIS...IOVINO
NEAR TERM...KRUZDLO
SHORT TERM...KRUZDLO
LONG TERM...IOVINO
AVIATION...IOVINO/KRUZDLO
MARINE...IOVINO/KRUZDLO
FIRE WEATHER...IOVINO/KRUZDLO



AREA FORECAST DISCUSSION

NWS LINCOLN IL

 1249 PM CDT TUE MAY 19 2015

.UPDATE...
ISSUED AT 1037 AM CDT TUE MAY 19 2015

SURFACE HIGH PRESSURE CENTERED OVER THE NORTHERN PLAINS WILL
CONTINUE TO SHIFT EASTWARD TODAY BRINGING LIGHT NORTHERLY WINDS
AND CONTINUED ADVECTION OF COOL AND RELATIVELY DRY AIR INTO
CENTRAL IL. GENERAL SUBSIDENCE ALOFT IS INDICATED BY MODEL
FORECASTS AND CURRENT WATER VAPOR IMAGERY, HOWEVER A BAND OF LOW
CLOUD OVER PORTIONS OF IL MAINLY NORTH OF I-72 PERSISTS THIS
MORNING. MODEL TIME-HEIGHT PLOTS NOW INDICATE THIS LAYER FAIRLY
WELL AND HRRR HALTS THE PROGRESS OF THE BAND AROUND THE CURRENT
LOCATION. SURFACE HEATING WILL TEND TO RAISE THE CEILING HEIGHT
THROUGH THE AFTERNOON...BUT ENOUGH MOISTURE SHOULD PERSIST THAT
THE LAYER SHOULD TRANSITION INTO A SCATTERED SHALLOW CUMULUS LAYER
AROUND 4000-5000 FEET. FORECAST IS MORE OR LESS ON TRACK, BUT HAVE
MADE SOME MODIFICATIONS TO CLOUD COVER THROUGH THE AFTERNOON TO
BETTER DEPICT THE SITUATION.

&&

.SHORT TERM...(TODAY)
ISSUED AT 331 AM CDT TUE MAY 19 2015

CANADIAN HIGH PRESSURE WILL BEGIN TO BUILD INTO CENTRAL AND
SOUTHEAST ILLINOIS TODAY, ACCOMPANIED BY A CONTINUED FEED OF
COOLER/DRIER AIR IN THE WAKE OF YESTERDAY`S COLD FRONT. THIS
SCENARIO SUPPORTS A DRY DAY, WITH AFTERNOON HIGH TEMPERATURES
MAINLY IN THE 60S.

ONE FLY IN THE OINTMENT, ONE THAT MAY IMPACT TEMPERATURES ACROSS
NORTHERN PORTIONS OF THE FORECAST AREA, IS A LARGE AREA OF WRAP-
AROUND CLOUDINESS THAT HAS STARTED TO SINK INTO FAR NORTHERN
PORTIONS OVER THE FORECAST AREA OVER THE PAST FEW HOURS. NONE OF THE
MODEL GUIDANCE HAS A VERY GOOD HANDLE ON THE CURRENT SOUTHERN EXTENT
OF THE CLOUD SHIELD, OR IN MANY CASES EVEN INDICATES IT AT ALL. AT
THIS POINT, HAVE USED SIMPLE EXTRAPOLATION OF THE CURRENT CLOUD
SHIELD INTO MID-MORNING. THEN, AS DIURNAL MIXING GETS GOING, HAVE
ALLOWED THE SOUTHERN EDGE OF THE CLOUD SHIELD TO MIX-OUT/ERODE AND
BE NORTH OF THE AREA BY MIDDAY. SO, BASICALLY, MUCH OF THE FORECAST
AREA ALONG/NORTH OF I-74 WILL BE CLOUDY TO START THE DAY, GRADUALLY
BECOMING MOSTLY SUNNY BY AFTERNOON.

.LONG TERM...(TONIGHT THROUGH MONDAY)
ISSUED AT 331 AM CDT TUE MAY 19 2015

CANADIAN HIGH PRESSURE WILL BE SPRAWLED NORTH OF IL ACROSS WI
TONIGHT KEEPING CENTRAL IL DRY. MID/HIGH CLOUDS TO INCREASE FROM THE
WEST DURING TONIGHT AHEAD OF NEXT WEATHER SYSTEM EJECTING INTO THE
CENTRAL PLAINS. LOWS TONIGHT IN THE MID TO UPPER 40S WITH COOLEST
READINGS OVER EAST CENTRAL IL WHERE CLOUDS MOVE IN LATER.

SHORT WAVE TO WEAKEN AS IT EJECTS INTO CENTRAL IL WED AFTERNOON AND
LIKELY SPREADING LIGHT RAIN SHOWERS EAST ACROSS CENTRAL AND SE IL
DURING THE DAY WED. SPC KEEPS CHANCES OF THUNDER SOUTH OF I-64 OVER
SOUTHERN IL ON WED BUT KEPT SLIGHT CHANCE OF THUNDER WED AFTERNOON
OVER SW CWA. NE FLOW AROUND HIGH PRESSURE OVER THE GREAT LAKES WILL
TRY TO BRING DRIER AIR INTO NE CWA WHERE RAINFALL AMOUNTS ONLY ONE
TO TWO TENTHS WHILE A QUARTER TO A THIRD OF AN INCH OF RAIN SW CWA.
BEST RAIN CHANCES SHIFT INTO SE IL WED EVENING WHILE THE IL RIVER
VALLEY DRIER OUT AS WEAKENING SYSTEM GETS SHUNTED TO THE SE AS
ANOTHER HIGH PRESSURE SYSTEM NOSES INTO IL FROM THE CENTRAL PLAINS.
WENT A FEW DEGREES COOLER THAN MET/MAV GUIDANCE FOR HIGHS WED
ESPECIALLY CENTRAL AND WESTERN AREAS WHERE HIGHER CHANCES OF
RAIN WITH MID TO UPPER 50S NORTH AND LOWER 60S IN SOUTHEAST IL.

HIGH PRESSURE SETTLES INTO MO THU AFTERNOON INTO THU NIGHT AND TO
BRING DRY WEATHER TO IL WITH RETURN OF PARTLY TO MOSTLY SUNNY SKIES
BY THU AFTERNOON. MILDER HIGHS IN THE MID TO UPPER 60S BUT STILL
BELOW NORMAL HIGHS IN THE MID 70S. LOWS THU NIGHT IN THE MID TO
UPPER 40S. A NICE DAY IN STORE FRIDAY AS HIGH PRESSURE SETTLES OVER
IL WITH AMPLE SUNSHINE...FAIRLY LIGHT WINDS AND HIGHS IN THE LOWER
70S. DRY CONDITIONS CONTINUE FRIDAY NIGHT ACROSS IL WITH LOWS IN THE
LOW TO MID 50S.

MOST OF CENTRAL AND ESPECIALLY EASTERN IL APPEAR TO STAY DRY YET ON
SATURDAY WITH INCREASING CLOUDS AND HIGHS IN THE MID 70S AS HIGH
PRESSURE SLIPS OFF THE MID ATLANTIC COAST BY SUNSET SATURDAY AND
UPPER LEVEL RIDGE INTO IL. HAVE SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS SAT AFTERNOON OVER WEST CENTRAL IL WHILE BETTER
CHANCES OF SHOWERS AND THUNDERSTORMS TO SPREAD NE ACROSS CENTRAL IL
DURING SAT NIGHT AND SUNDAY WITH SHORT WAVES EJECTING NE FROM THE
LARGE UPPER LEVEL TROF OVER THE ROCKIES. INCREASING GULF MOISTURE
WITH SOUTHERLY FLOW TO PROVIDE GOOD CHANCES OF SHOWERS AND
THUNDERSTORMS SUNDAY INTO MONDAY AND TO EVEN LINGER INTO NEXT
TUESDAY. A WARMER AND MORE HUMID STRETCH OF WEATHER FROM SUNDAY
THROUGH TUESDAY WITH HIGHS IN THE UPPER 70S (LOWER 80S IN SOUTHEAST
IL) AND DEWPOINTS IN THE 60S.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1249 PM CDT TUE MAY 19 2015

VFR CONDITIONS OVER MOST OF CENTRAL/SE IL THIS AFTERNOON...WITH
LINGERING MVFR CEILINGS KPIA-KBMI NORTHWARD. WITH DAYTIME
HEATING...CEILINGS SHOULD RAISE ABOVE MVFR THRESHOLDS WITHIN A FEW
HOURS ACROSS THE AREA...ALTHOUGH AREAS OF CLOUD COVER SCT-
BKN035-050 WILL LINGER THROUGH THE AFTERNOON ESPECIALLY KPIA-KBMI
NORTHWARD. LOW LEVEL CLOUD COVER DIMINISHING
EVENING/OVERNIGHT...THEN INCREASING LOW CLOUD COVER AND RAIN
SHOWERS AFTER 12Z. MODEL TIME-HEIGHT SECTIONS AND GUIDANCE
GENERALLY DEPICT CEILINGS REMAINING IN VFR RANGE UNTIL 18Z SO HAVE
INTRODUCED VCSH WITH CIGS/VSBY VFR STARTING 14-16Z. WINDS NNW
8-12 KTS DECREASING OVERNIGHT...THEN BECOMING ENE AROUND 10 KTS
AFTER 15Z WEDNESDAY.

&&

.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE...ONTON
SHORT TERM...BAK
LONG TERM...07
AVIATION...ONTON




AREA FORECAST DISCUSSION

NWS SHREVEPORT LA

 345 PM CDT TUE MAY 19 2015

.DISCUSSION...
OUR TEMPERATURES ARE IN THE LOW 80S NORTH TO MID 80S ELSEWHERE.
THE NORTHEAST WINDS ARE RUNNING OUT OF GAS. AS EXPECTED AFTERNOON
THUNDERSTORM INITIATION HAS OCCURRED OVER OUR TEXAS COUNTIES
LIFTING NORTHEAST WARD WITH MEAGER COVERAGE SO FAR. THE WINDS
THERE ARE MOIST FROM THE SOUTHEAST. FOR NOW...THE MORE STABLE AIR
REMAINS OVER OUR EAST AND MAYBE FOR A WHILE YET.

FARTHER WEST...THUNDERSTORMS ARE STRONGER AND TO SOME EXTENT A
BIT MORE NUMEROUS. THE WATER VAPOR SHOWS THE REASON IS A GOOD PUSH
OUT OF THE ROCKIES OUT INTO THE PLAINS WITH A LARGE UPPER LOW. THE
TAIL END OF THIS FEATURE WILL CONTINUE IT/S EVOLUTION BEYOND
SUNDOWN WITH THE EXPECTATION OF THE UPPER DIVERGENCE ALOFT AHEAD
OF THE LOW WORKING EAST OUT INTO THE MID SOUTH OVERNIGHT.

SO AFTER A BRIEF BREAK FROM THE ACTION WE HAVE THE WEAK FRONTAL
BOUNDARY NOW ALONG THE AR/LA STATE LINE OR SO WITH A CONTINUED
LIFT BACK TO THE NORTH OVERNIGHT. THE HRRR SHOWS A GOOD PUSH OF
QPF INTO OUR NW CORNER AFTER MIDNIGHT WITH MUCH OF THE DIURNAL
COVERAGE GONE HOURS EARLIER IN THE MID EVENING. THE NAM IS
SIMILAR...BUT MUCH SLOWER. THE RAIN THAT ACTUALLY FALLS IN THIS
AREA IS CRUCIAL TO RIVER FORECAST WHICH IS QPF DRIVEN. SO CLOSE
ATTENTION TO CONDITIONS IS MORE THAN WARRANTED WITH ALREADY PRETTY
HIGH WATER AND SOIL SATURATION AS YET ANOTHER FRONTAL BOUNDARY
WILL SETTLE INTO THE I-20 CORRIDOR LATE TOMORROW AND INTO EARLY
THURSDAY.

THE WEATHER PATTERN WILL NOT CHANGE GREATLY AS WE SEE ANOTHER
DEEP TROUGH MOVING INTO THE ROCKIES OVER THE WEEKEND AND OUT INTO
THE PLAINS EARLY NEXT WEEK.

&&

.PRELIMINARY POINT TEMPS/POPS...
SHV  69  86  70  79 /  20  30  50  40
MLU  69  88  69  79 /  20  30  50  40
DEQ  68  82  62  74 /  60  50  50  30
TXK  68  83  67  75 /  50  40  50  40
ELD  67  83  65  75 /  20  30  50  40
TYR  70  84  66  78 /  30  30  50  40
GGG  69  85  68  79 /  30  30  50  40
LFK  71  86  71  83 /  20  20  30  40

&&

.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&

$$

24




AREA FORECAST DISCUSSION

NWS GRAY ME

 1258 PM EDT TUE MAY 19 2015

.SYNOPSIS...
SHOWERS ASSOCIATED WITH A WARM FRONT WILL SPREAD ACROSS THE REGION
THIS MORNING. SHOWERS AND THUNDERSTORMS WILL DEVELOP THIS
AFTERNOON AND EVENING AHEAD OF A COLD FRONT. A NORTHWEST FLOW
WILL DEVELOP BEHIND THE FRONT TONIGHT AND PROVIDE COOL BUT MOSTLY
QUIET WEATHER INTO THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1 PM UPDATE...FORECAST REMAINS ON TRACK. SHOWERS WITH EMBEDDED
THUNDER DEVELOPING ACROSS UPSTATE NY IN ADVANCE OF COLD FRONT.
THESE WILL MOVE EASTWARD AND INTO THE CT VALLEY AROUND OR AFTER 4
PM. HEATING IS BEGINNING TO OCCUR THERE AND SHOULD CONTRIBUTE TO
ENOUGH CAPE TO SUSTAIN A FEW STRONG TO LOCALLY SEVERE STORMS LATE
THIS AFTERNOON.

950 AM UPDATE...HAVE UPDATED THE FORECAST TO FRESHEN UP THE TIMING
OF POPS TODAY AS WELL AS TEMPERATURES. OVERALL...FORECAST REMAINS
ON TRACK. WIDESPREAD RAIN THIS MORNING WILL PUSH OFF THE COAST IN
A FEW HOURS AND SHOULD ALLOW FOR AT LEAST PARTIAL SUNSHINE THIS
AFTERNOON...ESPECIALLY ACROSS THE INTERIOR. THIS WILL LEAD TO
INCREASING INSTABILITY. AS A SHORT WAVE TROUGH APPROACHES THIS
AFTERNOON...THUNDERSTORMS SHOULD DEVELOP IN UPSTATE NY AND VT AND
REACH THE CT VALLEY BY 4 PM. THE STORMS SHOULD THEN PROGRESS
EASTWARD AND EXIT THE COAST BETWEEN 8 AND 9 PM. A FEW SEVERE
STORMS WILL BE POSSIBLE...ESPECIALLY ACROSS NH.

PREVIOUSLY...

530AM UPDATE...
HAVE UPDATED HOURLY PRECIPITATION CHANCES BASED ON RECENT RADAR
TRENDS. MUCH OF THE AREA IS SEEING SHOWERS NOW EXCEPT THE
IMMEDIATE COAST. THIS WILL CHANGE SOON. BACK EDGE OF PRECIPITATION
MOVING INTO VERMONT NOW AND WILL REACH WESTERN NEW HAMPSHIRE
WITHIN THE NEXT 2 TO 3 HOURS.

ORIGINAL DISCUSSION...
AREA OF SHOWERS AND A FEW EMBEDDED THUNDERSTORMS IS MOVING THROUGH
THE HUDSON VALLEY EARLY THIS MORNING AND SHOULD ARRIVE IN NEW
HAMPSHIRE IN THE NEXT TWO HOURS BEFORE SPREADING EASTWARD ACROSS
THE REST OF NEW HAMPSHIRE AND WESTERN MAINE THIS MORNING. THIS
AREA OF PRECIPITATION IS ASSOCIATED WITH A WARM FRONT-LIKE
FEATURE IN THAT BEHIND IT DEWPOINTS ARE SURGING INTO THE MID 60S
WHILE THE COOL MARITIME AIR MASS AHEAD OF IT IS COOLER AND WITH
LOWER DEWPOINTS. BUT YOU WILL BE HARD PRESSED TO FIND A
NOTICEABLE WIND SHIFT OR PRESSURE TROUGH WITH IT. SUCH IS LIFE IN
NORTHERN NEW ENGLAND.

AREA OF RAIN WILL MOVE INTO THE MIDCOAST REGION OF MAINE LATE IN
THE MORNING AND PERSIST INTO THE AFTERNOON. WHILE NEW HAMPSHIRE
WILL SEE THE RAIN ENDING EARLIER IN THE MORNING. BREAKS IN THE
CLOUDS SHOULD ALLOW FOR PRETTY GOOD WARMING INTO THE MID TO UPPER
70S OVER WESTERN NEW HAMPSHIRE. THE COMBINATION OF THIS WARMING...
THE INCREASING LOW LEVEL MOISTURE... AND COOLING TEMPERATURES
ALOFT ASSOCIATED WITH A SHORTWAVE TROUGH WILL PROVIDE SUBSTANTIAL
INSTABILITY THIS AFTERNOON... PERHAPS THE BEST SEEN YET THIS
SEASON. CAPE APPROACHES OR EXCEEDS 1000 BY LATE THIS AFTERNOON AND
EARLY EVENING OVER VERMONT AND NEW HAMPSHIRE. JUST AS INSTABILITY
IS INCREASING... A COLD FRONT WILL BEGIN MOVING ACROSS NORTHERN
NEW ENGLAND FROM WEST TO EAST. THIS WILL PROVIDE LOW LEVEL
CONVERGENCE TO ADD LIFT TO THE EQUATION... AIDING IN THE
DEVELOPMENT OF THUNDERSTORMS. BEST INSTABILITY AND LIFT DOES NOT
ARRIVE UNTIL LATE IN THE DAY... SO THUNDERSTORM POTENTIAL SEEMS TO
BE MORE IN THE 4PM-8PM TIME PERIOD... WITH REMNANT STORMS LIKELY
MAINTAINING THEMSELVES THROUGH ELEVATED INSTABILITY THROUGH
MIDNIGHT TONIGHT.

MESOSCALE MODELS INCLUDING THE NAM AND HRRR INDICATING POTENTIALLY
TWO SEPARATE AREAS OF MORE WIDESPREAD THUNDERSTORM ACTIVITY LATE
THIS AFTERNOON. THE FIRST IS OVER THE NORTHERN ADIRONDACKS AND THE
SECOND OVER THE CATSKILLS... BOTH AREAS FIRING AS THE FRONT MOVES
THROUGH TO PROVIDE LIFT AND MAY BE ENHANCED DUE TO TERRAIN-BASED
INSTABILITY. IF THIS SCENARIO UNFOLDS... THEN THE NORTHERN AREA OF
THUNDERSTORMS WOULD MOVE EAST ACROSS VERMONT AND THE NORTHERN HALF
OF NEW HAMPSHIRE AND INTO NORTHWEST MAINE IN THE EVENING. THE
SOUTHERN CLUSTER WOULD MOVE EAST MAINLY INTO MASSACHUSETTS. HAVE
ORIENTED AFTERNOON/EVENING THUNDERSTORM CHANCES AS BEING GREATEST
IN THE NORTH WHERE THE MORE NORTHERN CLUSTER OF STORMS WOULD MOVE
ACROSS BUT HAVE MAINTAINED AT LEAST A CHANCE OF THUNDERSTORMS OVER
ALL OF NEW HAMPSHIRE AND EXTENDING INTO FAR WESTERN/NORTHERN
MAINE IN THE EVENING.

ONE FINAL INGREDIENT TO ADD TO THE MIX TODAY IS INCREASING WIND
SHEAR. BY EVENING... AROUND THE TIME THE FRONT WILL BE MOVING INTO
NEW HAMPSHIRE... WINDS ALOFT APPROACH 50 KT AT 700 MB WHILE
SURFACE WINDS ARE BROADLY LIGHT OUT OF THE SOUTH. THIS WILL
PROVIDE ENOUGH SPEED SHEAR TO PROVIDE STORM ORGANIZATION AND
SUPERCELL TYPE STRUCTURES. THIS MAKES SEVERE THUNDERSTORMS MORE
LIKELY... WITH DAMAGING WINDS AND HAIL BEING THE PRIMARY THREATS.
HOWEVER... GIVEN LOW LEVEL WINDS OUT OF THE SOUTH... CANNOT RULE
OUT THE POSSIBILITY OF AN ISOLATED TORNADO PARTICULARLY IN AREAS
WHERE LOW LEVEL WINDS ARE CHANNELED BY TERRAIN AND PRODUCE GREATER
LOCALIZED DIRECTIONAL SHEAR. HAVE MENTIONED THE THREAT OF DAMAGING
WINDS AND LARGE HAIL IN THE PUBLIC FORECAST FOR LATE THIS
AFTERNOON. HAVE ALSO ORIENTED HOURLY PRECIPITATION CHANCES TO
BETTER REFLECT THE IDEA THAT EARLY MORNING SHOWERS WILL MOVE EAST
BEFORE THE CHANCE OF THUNDERSTORMS ARRIVES LATE.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
COLD FRONT WILL PUSH EAST ACROSS THE REGION TONIGHT WITH
THUNDERSTORM ACTIVITY LIKELY LINGERING INTO THE EVENING...
POSSIBLY TO AROUND MIDNIGHT IN NORTHERN MAINE. COOLER AND DRIER
AIR WILL BE MOVING IN BEHIND THE COLD FRONT. COULD SEE SOME FOG
NEAR THE COAST BEFORE THE FRONT MOVES THROUGH AND BEGINS TO
MIX/DRY THINGS OUT. TEMPERATURES FALL INTO THE UPPER 40S AND LOW
50S.

WILL BE A COOLER DAY ON WEDNESDAY FOR MOST OF THE REGION. BUT ON
THE COAST IT MAY ACTUALLY BE A FEW DEGREES WARMER... A TYPICAL
RESULT OF A PASSING COLD FRONT AND A SHIFT TO OFFSHORE WINDS. HIGH
TEMPERATURES RANGE FROM THE MID 50S IN THE NORTH TO THE MID 60S
NEAR THE COAST. DEWPOINTS WILL BE FALLING INTO THE 30S WHICH WILL
MAKE IT DIFFICULT FOR ANY SHOWERS TO DEVELOP IN SPITE OF SOME LIFT
MOVING THROUGH WITH THE PASSING OF THE UPPER LEVEL TROUGH.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
A LARGE UPPER LEVEL TROUGH WILL DOMINATE THE FLOW ACROSS NEW
ENGLAND THROUGH THE WEEKEND. SEVERAL DISTURBANCES WILL ROTATE
AROUND THE TROUGH, HOWEVER, COOL DRY WEATHER WILL RULE FOR MUCH OF
THE PERIOD. A MOISTURE-STARVED FRONT DROPPING SOUTHWARD FROM
CANADA COULD BRING A FEW SHOWERS TO THE REGION FRIDAY. BEHIND THE
FRONT...TEMPERATURES WILL BE MAINLY IN THE 60S SATURDAY BUT SHOULD
START TO WARM INTO THE 70S MOST AREAS FOR SUNDAY AND MONDAY AS THE
TROUGH AXIS SLIDES EAST OF THE REGION. MODELS NOW DELAY NEXT
SIGNIFICANT PRECIPITATION UNTIL TUESDAY, ALLOWING FOR A VERY
PLEASANT HOLIDAY WEEKEND.

NOTE: THE FREEZE/FROST PROGRAM STARTS IN NORTHERN ZONES
THURSDAY MAY 21. LOW TEMPERATURES THURSDAY AND SATURDAY MORNINGS
WILL DROP NEAR OR BELOW FREEZING ACROSS NORTHERN ZONES AND MAY
REQUIRE FREEZE WARNINGS AND/OR FROST ADVISORIES.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
SHORT TERM...EARLY MORNING IFR/LIFR CONDITIONS WILL BEGIN
IMPROVING THIS MORNING EVEN AS AN AREA OF RAIN MOVES ACROSS THE
AREA. COULD SEE MVFR CEILINGS LINGER THROUGH MUCH OF THE DAY BUT
THERE IS A BETTER CHANCE THAT CONDITIONS WILL BREAK OUT TO VFR FOR
AT LEAST A FEW HOURS. THERE IS A CHANCE OF THUNDERSTORMS ACROSS
MUCH OF NEW HAMPSHIRE LATE THIS AFTERNOON INTO EARLY THIS EVENING.
LOW CLOUDS MAY MAKE A RETURN VISIT TO COASTAL MAINE EARLY THIS
EVENING BUT THE PASSING OF A COLD FRONT DURING THE NIGHT WILL
LIKELY IMPROVE CONDITIONS TO VFR EVENTUALLY.

LONG TERM...MAINLY VFR CONDITIONS EXPECTED.

&&

.MARINE...
SHORT TERM...SOUTHERLY FLOW INCREASES TODAY THEN SHIFTS TO THE
WEST TONIGHT BEHIND A COLD FRONT. WEST WINDS COULD GUST TO AROUND
20 KT ON WEDNESDAY.

LONG TERM...WITH MAINLY OFFSHORE FLOW...WINDS AND SEAS EXPECTED
TO REMAIN BELOW SCA CRITERIA. STRONGEST WINDS AND HIGHEST SEAS
SHOULD BE WELL OFFSHORE.

&&

.FIRE WEATHER...
MOIST AIR AND WIDESPREAD WETTING RAIN TODAY WILL KEEP FIRE DANGER
CONDITIONS LOW. DRY AIR MOVES IN BEHIND A COLD FRONT TONIGHT...
LEADING TO MUCH DRIER CONDITIONS WEDNESDAY INTO THE WEEKEND.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.

&&

$$

NEAR TERM...EKSTER




AREA FORECAST DISCUSSION

NWS MARQUETTE MI

 408 PM EDT TUE MAY 19 2015

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 407 PM EDT TUE MAY 19 2015

WV IMAGERY AND RAP ANALYSIS INDICATED A MID/UPPER LEVEL RIDGE OVER
WRN CANADA AND A DOWNSTREAM TROUGH FROM ERN CANADA INTO THE NRN
GREAT LAKES. STRONG MID-LEVEL DRYING WAS EVIDENT THROUGH THE NORTHERN
LAKES BEHIND A SHORTWAVE TROUGH THAT HAS MOVED EAST OF LAKE
SUPERIOR. AT THE SFC...HIGH PRES OVER THE ERN DAKOTAS WAS BUILDING
INTO THE UPPER MS VALLEY AN WRN LAKES BRINGING DIMINISHING NW WINDS
AND CLEARING SKIES. VIS LOOP SHOWED CLEAR SKIES OVER THE WEST AND
THINNING CLOUDS CENTRAL. RADAR ALSO INDICATED THAT THE REMAINING -
SHSN HAD QUICKLY DISSIPATED WITH ONLY SOME ISOLD FLURRIES OVER THE
EAST.

TONIGHT...AS THE HIGH PRES RIDGE BUILDS FROM WI INTO LOWER
MI...EXPECT SKIES TO CLEAR AND WEST WINDS TO DIMINISH/DECOUPLE.
FAVORABLE RADIATIONAL COOLING CONDITIONS WITH PWAT VALUES AT OR
BELOW 0.25 INCH WILL ALLOW TEMPS TO DROP TOWARD THE LOWER END OF
GUIDANCE. MIN READINGS INTO THE MID TO UPPER 20S INLAND ARE EXPECTED
TO TEMPS TO AROUND 30 CLOSER TO THE LAKES. ALTHOUGH OUR FROST/FREEZE
PROGRAM HAS NOT STARTED YET...WOULD EXPECT A WIDESPREAD FROST ACROSS
UPPER MICHIGAN AND A HARD FREEZE OVER THE INTERIOR WEST. AN SPS HAS
BEEN ISSUED TO HIGHLIGHT THE EXPECTED CONDITIONS.

WEDNESDAY...WITH DRY HIGH PRES DOMINATING...ABUNDANT SUNSHINE AND
MIXING TO AROUND 6K FT (850 MB TEMPS AROUND 4C) WILL SUPPORT INLAND
HIGHS IN TOE LOW TO MID 60S. LAKE BREEZES WILL KEEP READINGS IN THE
50S ALONG THE GREAT LAKES.

.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 328 PM EDT TUE MAY 19 2015

A QUIET FIRST HALF OF THE LONG TERM PERIOD IS IN STORE FOR THE UPPER
GREAT LAKES REGION...DUE TO THE AREA BEING BETWEEN AN UPPER TROUGH
OVER EASTERN CANADA AND ANOTHER OVER THE SOUTHWESTERN
CONUS. WHILE THE UPPER GREAT LAKES REGION WILL BE BRUSHED BY A FEW
WAVES ASSOCIATED WITH THESE FEATURES...THE OVERALL FLOW WILL BE OUT
OF THE NORTHWEST OR WEST-NORTHWEST WITH LIMITED MOISTURE.

HIGH PRESSURE WILL DOMINATE MUCH OF THE WEDNESDAY TO SATURDAY
PERIOD...WITH TEMPERATURES GENERALLY RUNNING BELOW NORMAL
(ESPECIALLY NEAR LAKE SUPERIOR). THE ONLY SIGNIFICANT ITEM OF NOTE
IS A COLD FRONT THAT WILL DROP SOUTH ACROSS THE REGION ON WEDNESDAY
NIGHT AND THURSDAY. WITH MOISTURE CONTINUING TO LOOK LIMITED...WILL
JUST SHOW PARTLY CLOUDY SKIES AS IT MOVES THROUGH THE AREA. THERE
ARE SOME HINTS THAT DIURNAL HEATING MAY BE ENOUGH TO KICK OFF A
STRAY SHOWER OVER SOUTHERN MENOMINEE COUNTY (MORE LIKELY IN
NORTHEAST WISCONSIN) WITH SOME HELP FROM A LAKE BREEZE OFF THE BAY
OF GREEN BAY. DON/T HAVE ENOUGH CONFIDENCE TO INCLUDE POPS FOR
ANY FARTHER NORTH THAN THE CITY OF MENOMINEE...BUT IT WILL BE
SOMETHING TO WATCH. ANOTHER BRIEF COOL DOWN IS EXPECTED BEHIND THE
FRONT WITH THE NORTHERLY FLOW OFF LAKE SUPERIOR BEFORE HIGHS SLOWLY
RISE TOWARDS MORE NORMAL VALUES ON SATURDAY (DUE TO THE HIGH
DEPARTING AND SOUTHERLY FLOW STARTING TO DEVELOP.

MODELS REMAIN CONSISTENT ON ENERGY FROM THE SOUTHWESTERN CONUS
TROUGH EJECTING NORTHEAST TOWARDS THE AREA SATURDAY NIGHT INTO
EARLY NEXT WEEK. A SURFACE LOW DEVELOPING IN THE PLAINS WITH THIS
FEATURE WILL MOVE INTO IOWA BY SUNDAY NIGHT BEFORE LIFTING
NORTHEAST THROUGH THE GREAT LAKES REGION MONDAY INTO MONDAY NIGHT.
THE LATEST TREND IS FOR THE LOW AND ASSOCIATED UPPER LEVEL WAVE TO
LIFT FARTHER TO THE NORTH THAN THOUGHT YESTERDAY...SO WILL TREND
POPS UP ON SUNDAY NIGHT AND MONDAY AS THE LOW MOVES THROUGH.
INSTABILITY AND MID LEVEL LAPSE RATES REMAIN WEAK DURING THAT
PERIOD...WITH THE AREA GENERALLY ON THE NORTHWEST SIDE OF THE
SURFACE LOW...SO WILL KEEP THUNDER OUT OF THE FORECAST. NEXT WEEK
STILL LOOKS TO BE UNSETTLED...AS THE UPPER TROUGH IN THE SOUTHWEST
CONUS WEAKENS AND LIFTS THROUGH THE CENTRAL CONUS.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 128 PM EDT TUE MAY 19 2015

AS HIGH PRESSURE BUILDS TOWARD THE AREA...EXPECT VFR CONDITIONS WITH
MUCH DRIER AIR AND MIXING AT KIWD AND INTO KCMX AND KSAW MID TO LATE
AFTERNOON AS NNW GRADUALLY DIMINISH.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 407 PM EDT TUE MAY 19 2015

AS HIGH PRES BUILDS ACROSS THE REGION FROM THE WEST AND THE PRES
GRADIENT WEAKENS...WINDS WILL DIMINISH TO LESS THAN 20 KNOTS. WED
THROUGH SAT...WINDS WILL BE UNDER 20KT AS SFC HIGH PRES REMAINS IN
CONTROL THROUGH MUCH OF THE PERIOD. A WEAK FRONT IS EXPECTED TO SAG
INTO THE REGION BY SUNDAY BUT WINDS WILL REMAIN GENERALLY LIGHT.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...JLB
LONG TERM...SRF
AVIATION...JLB
MARINE...JLB



AREA FORECAST DISCUSSION

NWS GRAND RAPIDS MI

 330 PM EDT TUE MAY 19 2015

LATEST UPDATE...
SYNOPSIS/SHORT TERM/LONG TERM/MARINE

.SYNOPSIS...
ISSUED AT 330 PM EDT TUE MAY 19 2015

A COOL AIR MASS HAS SETTLED INTO SOUTHWEST LOWER MICHIGAN AND FROST
AND FREEZING TEMPERATURES ARE A DISTINCT POSSIBILITY TONIGHT. A
FREEZE WARNING HAS BEEN POSTED FOR CENTRAL LOWER MICHIGAN AND A
FROST ADVISORY HAS BEEN HOISTED FOR THE REMAINING AREAS OF SOUTHWEST
LOWER MICHIGAN. DRY WEATHER IS EXPECTED THE REMAINDER OF THE WORK
WEEK. CONDITIONS WILL REMAIN ON THE COOL SIDE OF NORMAL THIS
WEEK...WITH A WARMUP AS WE MOVE THROUGH THE HOLIDAY WEEKEND. ALONG
WITH THE WARMER AIR WILL COME CHANCES FOR RAIN...ESPECIALLY SUNDAY
INTO MEMORIAL DAY.

&&

.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 330 PM EDT TUE MAY 19 2015

MAIN FOCUS OF THE SHORT TERM WAS ON WHETHER TO EXPAND A FROST
HEADLINE INTO THE COUNTIES THAT WERE NOT COVERED BY THE FREEZE
WARNING ACROSS CENTRAL LOWER. DECIDED TO DO THAT...SO A FROST
ADVISORY IS NOW IN PLACE FOR THE REST OF THE FORECAST
AREA...ESSENTIALLY FROM INTERSTATE 96 TO THE SOUTH. DRIER AIR
CONTINUES TO POUR INTO THE AREA ON NORTHWEST WINDS...WITH THE DEW
POINT CURRENTLY AT GRAND RAPIDS AT 31 DEGREES. THINKING THE
STRATOCUMULUS WILL FADE WITH THE SETTING SUN THIS EVENING WHICH
SHOULD SET UP OK RADIATIONAL CONDITIONS. ONE ITEM OF CONCERN IS A
CORE OF WIND THAT IS SEEN IN NAM CROSS SECTIONS IN BUFKIT.
STILL...GIVEN A DECENT AMOUNT OF MAINLY CLEAR SKIES TONIGHT AND VERY
DRY/COOL AIR ALREADY IN PLACE FELT HEADLINES WERE WARRANTED ACROSS
THE FORECAST AREA.

THE REMAINDER OF THE SHORT TERM WILL BE QUIET. WE HAVE A DRY
FORECAST IN PLACE TONIGHT THROUGH THURSDAY NIGHT. THERE IS A
SHORTWAVE THAT SLIDES BY THE SOUTHERN GREAT LAKES TOMORROW NIGHT
INTO THURSDAY...BUT HAVE SIDED WITH THE DRY ECMWF AND GFS MODELS.
THE PRECIP SHOULD MISS US JUST TO THE SOUTH. ALSO ON THURSDAY...A
WEAK TROUGH MOVES THROUGH THE LOWER PENINSULA WITH SOME SPOTTY
PRECIP AMOUNTS BEING KICKED OUT BY THE MODELS. MOISTURE IS NOT ALL
THAT DEEP IN THE WED NIGHT THROUGH THURS NIGHT TIME FRAME SO AM
OPTING FOR DRY.

IT WILL BE COOL THE NEXT SEVERAL DAYS WITH NO MAJOR WARM ADVECTION
PUSH AT 850MB/S.

.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 330 PM EDT TUE MAY 19 2015

THE MAIN FOCUS IN THE LONG TERM WILL BE THE POSSIBILITY FOR WET
WEATHER AND GUSTY WINDS GOING INTO THE HOLIDAY WEEKEND.

HIGH PRESSURE WILL BE IN CONTROL EARLY IN THE PERIOD FROM FRIDAY
THROUGH THE MAJORITY OF SATURDAY. AS HIGH PRESSURE PROGRESSES TO THE
EAST AN AREA OF LOW PRESSURE WILL BEGIN TO EJECT OUT OF THE
SOUTHWEST AND INTO THE CENTRAL PLAINS. A WARM FRONTAL BOUNDARY WILL
EXTEND OUT AHEAD OF THE SYSTEM...GIVING WAY TO SOUTHERLY INFLUENCE.
THIS SYSTEM WILL TAKE SOMEWHAT OF A SIMILAR TRACK TO LAST WEEKENDS
SYSTEM...THROUGH THE UPPER MIDWEST.

THE BEST PRECIPITATION CHANCES WILL LIKELY BE LATE SATURDAY NIGHT
INTO SUNDAY MORNING AND AGAIN MONDAY AFTERNOON AND EVENING. SATURDAY
NIGHTS RAINFALL WILL BE ASSOCIATED WITH THE RESULTING ISENTROPIC
LIFT WITH THE PASSAGE OF THE WARM FRONT. LOW PRESSURE THEN
TRANSITIONS FROM A CLOSED LOW TO A SHORT WAVE THAT IS EVENTUALLY
CONSUMED AROUND THE MAIN CYCLONIC FLOW NEAR THE HUDSON BAY. THE WARM
FRONTAL BOUNDARY GETS HINGED UP OVER CENTRAL AND NORTHERN LOWER
MICHIGAN AND BECOMES NEARLY STATIONARY. WE MAY VERY WELL SEE A LULL
IN ACTIVITY SUNDAY AFTERNOON AS WE LOSE THE LIFT.

GOING INTO MEMORIAL DAY IS WHERE WE SEE THE POSSIBILITY OF GUSTY
WINDS AND THE POTENTIAL FOR THUNDERSTORMS. WHILE UPPER LEVEL WINDS
ARE NOT SO IMPRESSIVE...AN 850MB JET CORE OF 40-50KTS MOVES OVER THE
SOUTHERN PORTIONS OF THE FORECAST AREA. THIS IS SOMETHING THAT WOULD
USUALLY TRIGGER SOME CONCERN...BUT THERE ARE A COUPLE OF LIMITING
FACTORS TO ANY REAL ORGANIZED CONVECTION. THE BEST LIFT WOULD REMAIN
NORTH ALONG THE BOUNDARY...WHILE THE BEST CAPE STAYS SOUTHEAST OF
GRAND RAPIDS. THIS MAY BE SOMETHING TO WATCH AS WE CREEP CLOSER TO
MONDAY IF CONDITIONS BECOME BETTER ORGANIZED. OTHERWISE...IT SEEMS
THE HOLIDAY WILL HAVE SCATTERED AFTERNOON THUNDERSTORMS...SOME
LOCALIZED HEAVY RAINFALL AND GUSTY WINDS.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 219 PM EDT TUE MAY 19 2015

DRIER AIR WILL CONTINUE TO WORK INTO THE REGION OVER THE NEXT
SEVERAL HOURS. MVFR CONDITIONS WILL GRADUALLY IMPROVE WITH VFR
CONDITIONS EXPECTED AREA WIDE. GUSTY WINDS SHOULD CALM THROUGH
LATE THIS EVENING AND OVERNIGHT TONIGHT. CLEAR SKIES WILL SETTLE
ALSO SETTLE IN. HIGH LEVEL SCATTERED/BROKEN CLOUDS MAY FILTER IN
NEAR DAWN ON WEDNESDAY WITH WINDS REMAINING AROUND OR BELOW 5KTS.
NO REAL IMPACTS ARE EXPECTED THROUGH 18Z WEDNESDAY WITH VFR
CONDITIONS EXPECTED.

&&

.MARINE...
ISSUED AT 330 PM EDT TUE MAY 19 2015

EXTENDED THE SMALL CRAFT ADVISORY THROUGH 800 PM. OBS ARE STILL GUST
TO AROUND 20 KNOTS IN MOST AREAS. THE BUOYS AT LAST CHECK ARE IN THE
3 TO 5 FOOT RANGE AT MUSKEGON...PORT SHELDON AND SOUTH HAVEN IN
TERMS OF WAVE HEIGHTS. EXPECTING THINGS TO DIMINISH TONIGHT. ONE
POSSIBLE ISSUE IS HIGH RESOLUTION GUIDANCE LIKE THE HRRR IS SHOWING
A SURGE IN WINDS FROM HOLLAND SOUTH AFTER DARK. THIS IS LIKELY DUE
TO SOME CHANNELING AND FUNNELING DOWN THE SHORELINE IN NORTHERLY
FLOW. THE EVENING SHIFT WILL BE MONITORING THE LATEST TRENDS IN THE
HIGH RESO GUIDANCE FOR A POSSIBLE EXTENTION IN TIME SOUTH OF
HOLLAND. THE SOUTH HAVEN GLERL OB ON THE PIER AND THE BUOY JUST
OFFSHORE WILL BE THE PIECES OF DATA TO WATCH AFTER DARK TO SEE IF
THE HRRR VERIFIES. OTHERWISE FAIRLY LIGHT WINDS THE NEXT FEW DAYS.

&&

.HYDROLOGY...
ISSUED AT 140 PM EDT MON MAY 18 2015

IN GENERAL...RIVER LEVELS ACROSS SOUTHWEST LOWER MICHIGAN ARE
GRADUALLY FALLING. THAT WILL CONTINUE TO BE THE CASE WITH LIMITED
QPF THIS WEEK. FAIR WEATHER WILL DOMINATE FOR THE REST OF THE WEEK
INTO AT LEAST SATURDAY. THE NEXT SIGNIFICANT CHANCE FOR WIDESPREAD
RAINFALL WILL BE LATE IN THE HOLIDAY WEEKEND INTO NEXT WEEK.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...FROST ADVISORY FROM MIDNIGHT TONIGHT TO 8 AM EDT WEDNESDAY FOR
     MIZ050-056>059-064>067-071>074.

     FREEZE WARNING FROM MIDNIGHT TONIGHT TO 8 AM EDT WEDNESDAY FOR
     MIZ037>040-043>046-051-052.

LM...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LMZ844>849.

&&

$$

SYNOPSIS...DUKE
SHORT TERM...DUKE
LONG TERM...JAM
AVIATION...JAM
HYDROLOGY...EBW/CAS
MARINE...DUKE



AREA FORECAST DISCUSSION

NWS GRAND RAPIDS MI

 307 PM EDT TUE MAY 19 2015

LATEST UPDATE...
SYNOPSIS/SHORT TERM/LONG TERM/MARINE

.SYNOPSIS...
ISSUED AT 307 PM EDT TUE MAY 19 2015

A COOL AIR MASS HAS SETTLED INTO SOUTHWEST LOWER MICHIGAN AND FROST
AND FREEZING TEMPERATURES ARE A DISTINCT POSSIBILITY TONIGHT. A
FREEZE WARNING HAS BEEN POSTED FOR CENTRAL LOWER MICHIGAN AND A
FROST ADVISORY HAS BEEN HOISTED FOR THE REMAINING AREAS OF SOUTHWEST
LOWER MICHIGAN. DRY WEATHER IS EXPECTED THE REMAINDER OF THE WORK
WEEK. CONDITIONS WILL REMAIN ON THE COOL SIDE OF NORMAL THIS
WEEK...WITH A WARMUP AS WE MOVE THROUGH THE HOLIDAY WEEKEND. ALONG
WITH THE WARMER AIR WILL COME CHANCES FOR RAIN...ESPECIALLY SUNDAY
INTO MEMORIAL DAY.

&&

.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 307 PM EDT TUE MAY 19 2015

MAIN FOCUS OF THE SHORT TERM WAS ON WHETHER TO EXPAND A FROST
HEADLINE INTO THE COUNTIES THAT WERE NOT COVERED BY THE FREEZE
WARNING ACROSS CENTRAL LOWER. DECIDED TO DO THAT...SO A FROST
ADVISORY IS NOW IN PLACE FOR THE REST OF THE FORECAST
AREA...ESSENTIALLY FROM INTERSTATE 96 TO THE SOUTH. DRIER AIR
CONTINUES TO POUR INTO THE AREA ON NORTHWEST WINDS...WITH THE DEW
POINT CURRENTLY AT GRAND RAPIDS AT 31 DEGREES. THINKING THE
STRATOCUMULUS WILL FADE WITH THE SETTING SUN THIS EVENING WHICH
SHOULD SET UP OK RADIATIONAL CONDITIONS. ONE ITEM OF CONCERN IS A
CORE OF WIND THAT IS SEEN IN NAM CROSS SECTIONS IN BUFKIT.
STILL...GIVEN A DECENT AMOUNT OF MAINLY CLEAR SKIES TONIGHT AND VERY
DRY/COOL AIR ALREADY IN PLACE FELT HEADLINES WERE WARRANTED ACROSS
THE FORECAST AREA.

THE REMAINDER OF THE SHORT TERM WILL BE QUIET. WE HAVE A DRY
FORECAST IN PLACE TONIGHT THROUGH THURSDAY NIGHT. THERE IS A
SHORTWAVE THAT SLIDES BY THE SOUTHERN GREAT LAKES TOMORROW NIGHT
INTO THURSDAY...BUT HAVE SIDED WITH THE DRY ECMWF AND GFS MODELS.
THE PRECIP SHOULD MISS US JUST TO THE SOUTH. ALSO ON THURSDAY...A
WEAK TROUGH MOVES THROUGH THE LOWER PENINSULA WITH SOME SPOTTY
PRECIP AMOUNTS BEING KICKED OUT BY THE MODELS. MOISTURE IS NOT ALL
THAT DEEP IN THE WED NIGHT THROUGH THURS NIGHT TIME FRAME SO AM
OPTING FOR DRY.

IT WILL BE COOL THE NEXT SEVERAL DAYS WITH NO MAJOR WARM ADVECTION
PUSH AT 850MB/S.

.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 307 PM EDT TUE MAY 19 2015

THE MAIN FOCUS IN THE LONG TERM WILL BE THE POSSIBLITY FOR WET
WEATHER AND GUSTY WINDS GOING INTO THE HOLIDAY WEEKEND.

HIGH PRESSURE WILL BE IN CONTROL EARLY IN THE PERIOD FROM FRIDAY
THROUGH THE MAJORITY OF SATURDAY. AS HIGH PRESSURE PROGRESSES TO THE
EAST AN AREA OF LOW PRESSURE WILL BEGIN TO EJECT OUT OF THE
SOUTHWEST AND INTO THE CENTRAL PLAINS. A WARM FRONTAL BOUNDARY WILL
EXTEND OUT AHEAD OF THE SYSTEM...GIVING WAY TO SOUTHERLY INFLUENCE.
THIS SYSTEM WILL TAKE SOMEWHAT OF A SIMILAR TRACK TO LAST WEEKENDS
SYSTEM...THROUGH THE UPPER MIDWEST.

THE BEST PRECIPITION CHANCES WILL LIKELY BE LATE SATURDAY NIGHT INTO
SUNDAY MORNING AND AGAIN MONDAY AFTERNOON AND EVENING. SATURDAY
NIGHTS RAINFALL WILL BE ASSOCIATED WITH THE RESULTING ISENTROPIC
LIFT WITH THE PASSAGE OF THE WARM FRONT. LOW PRESSURE THEN
TRANSITIONS FROM A CLOSED LOW TO A SHORT WAVE THAT IS EVENTUALLY
CONSUMED AROUND THE MAIN CYCLONIC FLOW NEAR THE HUDSON BAY. THE WARM
FRONTAL BOUNDARY GETS HINGED UP OVER CENTRAL AND NORTHERN LOWER
MICHIGAN AND BECOMES NEARLY STATIONARY. WE MAY VERY WELL SEE A LULL
IN ACTIVITY SUNDAY AFTERNOON AS WE LOSE THE LIFT.

GOING INTO MEMORIAL DAY IS WHERE WE SEE THE POSSIBILITY OF GUSTY
WINDS AND THE POTENTIAL FOR THUNDERSTORMS. WHILE UPPER LEVEL WINDS
ARE NOT SO IMPRESSIVE...AN 850MB JET CORE OF 40-50KTS MOVES OVER THE
SOUTHERN PORTIONS OF THE FORECAST AREA. THIS IS SOMETHING THAT WOULD
USUALLY TRIGGER SOME CONCERN...BUT THERE ARE A COUPLE OF LIMITING
FACTORS TO ANY REAL ORGANIZED CONVECTION. THE BEST LIFT WOULD REMAIN
NORTH ALONG THE BOUNDARY...WHILE THE BEST CAPE STAYS SOUTHEAST OF
GRAND RAPIDS. THIS MAY BE SOMETHING TO WATCH AS WE CREEP CLOSER TO
MONDAY IF CONDITIONS BECOME BETTER ORGANIZED. OTHERWISE...IT SEEMS
THE HOLIDAY WILL HAVE SCATTERED AFTERNOON THUNDERSTORMS...SOME
LOCALIZED HEAVY RAINFALL AND GUSTY WINDS.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 219 PM EDT TUE MAY 19 2015

DRIER AIR WILL CONTINUE TO WORK INTO THE REGION OVER THE NEXT
SEVERAL HOURS. MVFR CONDITIONS WILL GRADUALLY IMPROVE WITH VFR
CONDITIONS EXPECTED AREA WIDE. GUSTY WINDS SHOULD CALM THROUGH
LATE THIS EVENING AND OVERNIGHT TONIGHT. CLEAR SKIES WILL SETTLE
ALSO SETTLE IN. HIGH LEVEL SCATTERED/BROKEN CLOUDS MAY FILTER IN
NEAR DAWN ON WEDNESDAY WITH WINDS REMAINING AROUND OR BELOW 5KTS.
NO REAL IMPACTS ARE EXPECTED THROUGH 18Z WEDNESDAY WITH VFR
CONDITIONS EXPECTED.

&&

.MARINE...
ISSUED AT 307 PM EDT TUE MAY 19 2015

EXTENDED THE SMALL CRAFT ADVISORY THROUGH 800 PM. OBS ARE STILL GUST
TO AROUND 20 KNOTS IN MOST AREAS. THE BUOYS AT LAST CHECK ARE IN THE
3 TO 5 FOOT RANGE AT MUSKEGON...PORT SHELDON AND SOUTH HAVEN IN
TERMS OF WAVE HEIGHTS. EXPECTING THINGS TO DIMINISH TONIGHT. ONE
POSSIBLE ISSUE IS HIGH RESOLUTION GUIDANCE LIKE THE HRRR IS SHOWING
A SURGE IN WINDS FROM HOLLAND SOUTH AFTER DARK. THIS IS LIKELY DUE
TO SOME CHANNELLING AND FUNNELLING DOWN THE SHORELINE IN NORTHERLY
FLOW. THE EVENING SHIFT WILL BE MONITORING THE LATEST TRENDS IN THE
HIGH RESO GUIDANCE FOR A POSSIBLE EXTENTION IN TIME SOUTH OF
HOLLAND. THE SOUTH HAVEN GLERL OB ON THE PIER AND THE BUOY JUST
OFFSHORE WILL BE THE PIECES OF DATA TO WATCH AFTER DARK TO SEE IF
THE HRRR VERIFIES. OTHERWISE FAIRLY LIGHT WINDS THE NEXT FEW DAYS.

&&

.HYDROLOGY...
ISSUED AT 140 PM EDT MON MAY 18 2015

IN GENERAL...RIVER LEVELS ACROSS SOUTHWEST LOWER MICHIGAN ARE
GRADUALLY FALLING. THAT WILL CONTINUE TO BE THE CASE WITH LIMITED
QPF THIS WEEK. FAIR WEATHER WILL DOMINATE FOR THE REST OF THE WEEK
INTO AT LEAST SATURDAY. THE NEXT SIGNIFICANT CHANCE FOR WIDESPREAD
RAINFALL WILL BE LATE IN THE HOLIDAY WEEKEND INTO NEXT WEEK.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...FROST ADVISORY FROM MIDNIGHT TONIGHT TO 8 AM EDT WEDNESDAY FOR
     MIZ050-056>059-064>067-071>074.

     FREEZE WARNING FROM MIDNIGHT TONIGHT TO 8 AM EDT WEDNESDAY FOR
     MIZ037>040-043>046-051-052.

LM...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LMZ844>849.

&&

$$

SYNOPSIS...DUKE
SHORT TERM...DUKE
LONG TERM...JAM
AVIATION...JAM
HYDROLOGY...EBW/CAS
MARINE...DUKE



AREA FORECAST DISCUSSION

NWS MARQUETTE MI

 329 PM EDT TUE MAY 19 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 506 AM EDT TUE MAY 19 2015

LATEST WV IMAGERY AND RAP ANALYSIS INDICATED A MID/UPPER LEVEL
TROUGH FROM NE CANADA EXTENDING INTO THE UPPER GREAT LAKES WITH THE
WEAKENING REMANTS OF THE MID-LVL LOW CIRCULATION CENTER SW OF JAMES
BAY. AT THE SFC...A TROUGH EXTENDED ACROSS THE UPPER GREAT LAKES
FROM LOW PRES NOW OVER QUEBEC. WRAPAROUND MOISTURE FROM THE LOW
CIRCULATION STILL SUSTAINING SNOW SHOWERS MIXED WITH RAIN SHOWERS
ACROSS PORTIONS OF NRN UPPER MI EARLY THIS MORNING AS NOTED ON THE
MQT RADAR.

TODAY...SFC HIGH PRES WILL BUILD TOWARD THE AREA DURING THE DAY AS
LOW-LEVEL FLOW BECOMES INCREASINGLY ANTICYCLONIC. THE ASSOCIATED
DRYING AS THE DEEPER MOISTURE DEPARTS TO THE EAST WILL ALLOW ANY
LINGERING SNOW SHOWERS TO GRADUALLY DIMINISH THIS MORNING FROM WEST
TO EAST AND END OVER MOST OF THE CWA BY 18Z. ONLY A DUSTING TO MAYBE
HALF AN INCH OF SNOW ACCUMULATION IS POSSIBLE ON GRASSY AREAS OF
NORTH CENTRAL HIGHER TERRAIN LOCATIONS BEFORE SNOW ENDS THIS
MORNING. CLOUDS WILL SLOWLY DISSIPATE FROM WEST TO EAST MAINLY
DURING THE MID TO LATE AFTERNOON WITH HIGHER PRESSURE AND ASSOC
DRIER AIR WORKING IN FM WEST. OTHERWISE...UNSEASONABLY COLD
CONDITIONS ARE EXPECTED UNDER GUSTY NW WINDS (20 TO 25 MPH
ESPECIALLY EAST HALF) AS HIGHS WILL RANGE FROM UPPER 30S/LOWER 40S
NORTH AND EAST TO THE MID AND UPPER 40S SOUTH AND WEST.

TONIGHT...HIGH PRESSURE BUILDS INTO THE AREA TONIGHT. THE DRY AIR
ASSOCIATED WITH THE HIGH WILL DIMINISH ANY LINGERING CLOUDS OVER THE
EASTERN CWA QUICKLY DURING THE EARLY EVENING HOURS. THE CLEARING
SKIES AND WEAKENING WINDS WILL LEAD TO A COLD NIGHT ACROSS THE AREA.
HAVE FOLLOWED THE LOWER END OF MODEL GUIDANCE (GIVEN PWAT VALUES AT
OR BELOW 0.25IN ACROSS MUCH OF THE INTERIOR)...WHICH INDICATES
VALUES IN THE 20S FOR MOST INTERIOR LOCATIONS...COLDEST INTERIOR
WEST ALONG THE WI BORDER WHERE LOWS COULD DIP INTO THE LOWER TO MID
20S. ALTHOUGH OUR FROST/FREEZE PROGRAM HASN/T STARTED YET...WOULD
EXPECT A WIDESPREAD FROST ACROSS UPPER MICHIGAN AND A HARD FREEZE
OVER THE INTERIOR WEST. PERSONS WITH SENSITIVE PLANTS SHOULD TAKE
THE NECESSARY PRECAUTIONS TO PROTECT AGAINST A HARD FROST AND/OR
FREEZE AND WILL INCLUDE A MENTION OF THIS IN THE HWO STATEMENT.

.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 328 PM EDT TUE MAY 19 2015

A QUIET FIRST HALF OF THE LONG TERM PERIOD IS IN STORE FOR THE UPPER
GREAT LAKES REGION...DUE TO THE AREA BEING BETWEEN AN UPPER TROUGH
OVER EASTERN CANADA AND ANOTHER OVER THE SOUTHWESTERN
CONUS. WHILE THE UPPER GREAT LAKES REGION WILL BE BRUSHED BY A FEW
WAVES ASSOCIATED WITH THESE FEATURES...THE OVERALL FLOW WILL BE OUT
OF THE NORTHWEST OR WEST-NORTHWEST WITH LIMITED MOISTURE.

HIGH PRESSURE WILL DOMINATE MUCH OF THE WEDNESDAY TO SATURDAY
PERIOD...WITH TEMPERATURES GENERALLY RUNNING BELOW NORMAL
(ESPECIALLY NEAR LAKE SUPERIOR). THE ONLY SIGNIFICANT ITEM OF NOTE
IS A COLD FRONT THAT WILL DROP SOUTH ACROSS THE REGION ON WEDNESDAY
NIGHT AND THURSDAY. WITH MOISTURE CONTINUING TO LOOK LIMITED...WILL
JUST SHOW PARTLY CLOUDY SKIES AS IT MOVES THROUGH THE AREA. THERE
ARE SOME HINTS THAT DIURNAL HEATING MAY BE ENOUGH TO KICK OFF A
STRAY SHOWER OVER SOUTHERN MENOMINEE COUNTY (MORE LIKELY IN
NORTHEAST WISCONSIN) WITH SOME HELP FROM A LAKE BREEZE OFF THE BAY
OF GREEN BAY. DON/T HAVE ENOUGH CONFIDENCE TO INCLUDE POPS FOR
ANY FARTHER NORTH THAN THE CITY OF MENOMINEE...BUT IT WILL BE
SOMETHING TO WATCH. ANOTHER BRIEF COOL DOWN IS EXPECTED BEHIND THE
FRONT WITH THE NORTHERLY FLOW OFF LAKE SUPERIOR BEFORE HIGHS SLOWLY
RISE TOWARDS MORE NORMAL VALUES ON SATURDAY (DUE TO THE HIGH
DEPARTING AND SOUTHERLY FLOW STARTING TO DEVELOP.

MODELS REMAIN CONSISTENT ON ENERGY FROM THE SOUTHWESTERN CONUS
TROUGH EJECTING NORTHEAST TOWARDS THE AREA SATURDAY NIGHT INTO
EARLY NEXT WEEK. A SURFACE LOW DEVELOPING IN THE PLAINS WITH THIS
FEATURE WILL MOVE INTO IOWA BY SUNDAY NIGHT BEFORE LIFTING
NORTHEAST THROUGH THE GREAT LAKES REGION MONDAY INTO MONDAY NIGHT.
THE LATEST TREND IS FOR THE LOW AND ASSOCIATED UPPER LEVEL WAVE TO
LIFT FARTHER TO THE NORTH THAN THOUGHT YESTERDAY...SO WILL TREND
POPS UP ON SUNDAY NIGHT AND MONDAY AS THE LOW MOVES THROUGH.
INSTABILITY AND MID LEVEL LAPSE RATES REMAIN WEAK DURING THAT
PERIOD...WITH THE AREA GENERALLY ON THE NORTHWEST SIDE OF THE
SURFACE LOW...SO WILL KEEP THUNDER OUT OF THE FORECAST. NEXT WEEK
STILL LOOKS TO BE UNSETTLED...AS THE UPPER TROUGH IN THE SOUTHWEST
CONUS WEAKENS AND LIFTS THROUGH THE CENTRAL CONUS.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 128 PM EDT TUE MAY 19 2015

AS HIGH PRESSURE BUILDS TOWARD THE AREA...EXPECT VFR CONDITIONS WITH
MUCH DRIER AIR AND MIXING AT KIWD AND INTO KCMX AND KSAW MID TO LATE
AFTERNOON AS NNW GRADUALLY DIMINISH.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 506 AM EDT TUE MAY 19 2015

LOW PRES CENTERED OVER QUEBEC WILL CONTINUE TO LIFT NE TODAY AS HIGH
PRES GRADUALLY BUILDS IN FM THE WEST. NNW WINDS TO 20 TO 30 KNOTS
(HIGHEST EAST HALF) THIS MORNING WILL DIMINISH W TO E THIS
AFTERNOON/TONIGHT AS THE HIGH BUILDS IN FM THE WEST DECREASING THE
PRES GRADIENT. WED THRROUGH SAT...WINDS WILL BE UNDER 20KT AS SFC
HIGH PRES REMAINS IN CONTROL THROUGH MUCH OF THE PERIOD.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...VOSS
LONG TERM...SRF
AVIATION...JLB
MARINE...VOSS




AREA FORECAST DISCUSSION

NWS MARQUETTE MI

 132 PM EDT TUE MAY 19 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 506 AM EDT TUE MAY 19 2015

LATEST WV IMAGERY AND RAP ANALYSIS INDICATED A MID/UPPER LEVEL
TROUGH FROM NE CANADA EXTENDING INTO THE UPPER GREAT LAKES WITH THE
WEAKENING REMANTS OF THE MID-LVL LOW CIRCULATION CENTER SW OF JAMES
BAY. AT THE SFC...A TROUGH EXTENDED ACROSS THE UPPER GREAT LAKES
FROM LOW PRES NOW OVER QUEBEC. WRAPAROUND MOISTURE FROM THE LOW
CIRCULATION STILL SUSTAINING SNOW SHOWERS MIXED WITH RAIN SHOWERS
ACROSS PORTIONS OF NRN UPPER MI EARLY THIS MORNING AS NOTED ON THE
MQT RADAR.

TODAY...SFC HIGH PRES WILL BUILD TOWARD THE AREA DURING THE DAY AS
LOW-LEVEL FLOW BECOMES INCREASINGLY ANTICYCLONIC. THE ASSOCIATED
DRYING AS THE DEEPER MOISTURE DEPARTS TO THE EAST WILL ALLOW ANY
LINGERING SNOW SHOWERS TO GRADUALLY DIMINISH THIS MORNING FROM WEST
TO EAST AND END OVER MOST OF THE CWA BY 18Z. ONLY A DUSTING TO MAYBE
HALF AN INCH OF SNOW ACCUMULATION IS POSSIBLE ON GRASSY AREAS OF
NORTH CENTRAL HIGHER TERRAIN LOCATIONS BEFORE SNOW ENDS THIS
MORNING. CLOUDS WILL SLOWLY DISSIPATE FROM WEST TO EAST MAINLY
DURING THE MID TO LATE AFTERNOON WITH HIGHER PRESSURE AND ASSOC
DRIER AIR WORKING IN FM WEST. OTHERWISE...UNSEASONABLY COLD
CONDITIONS ARE EXPECTED UNDER GUSTY NW WINDS (20 TO 25 MPH
ESPECIALLY EAST HALF) AS HIGHS WILL RANGE FROM UPPER 30S/LOWER 40S
NORTH AND EAST TO THE MID AND UPPER 40S SOUTH AND WEST.

TONIGHT...HIGH PRESSURE BUILDS INTO THE AREA TONIGHT. THE DRY AIR
ASSOCIATED WITH THE HIGH WILL DIMINISH ANY LINGERING CLOUDS OVER THE
EASTERN CWA QUICKLY DURING THE EARLY EVENING HOURS. THE CLEARING
SKIES AND WEAKENING WINDS WILL LEAD TO A COLD NIGHT ACROSS THE AREA.
HAVE FOLLOWED THE LOWER END OF MODEL GUIDANCE (GIVEN PWAT VALUES AT
OR BELOW 0.25IN ACROSS MUCH OF THE INTERIOR)...WHICH INDICATES
VALUES IN THE 20S FOR MOST INTERIOR LOCATIONS...COLDEST INTERIOR
WEST ALONG THE WI BORDER WHERE LOWS COULD DIP INTO THE LOWER TO MID
20S. ALTHOUGH OUR FROST/FREEZE PROGRAM HASN/T STARTED YET...WOULD
EXPECT A WIDESPREAD FROST ACROSS UPPER MICHIGAN AND A HARD FREEZE
OVER THE INTERIOR WEST. PERSONS WITH SENSITIVE PLANTS SHOULD TAKE
THE NECESSARY PRECAUTIONS TO PROTECT AGAINST A HARD FROST AND/OR
FREEZE AND WILL INCLUDE A MENTION OF THIS IN THE HWO STATEMENT.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 238 AM EDT TUE MAY 19 2015

FROM WEDNESDAY THROUGH THE END OF THE WORK WEEK...A 500MB TROUGH
WILL REMAIN ACROSS THE GREAT LAKES REGION. THE LOW ITSELF WILL GET
AS CLOSE AS JAMES BAY THURSDAY AFTERNOON. AT THE SFC MUCH OF THIS
TIME PERIOD WILL BE MARKED BY A RIDGE OF HIGH PRESSURE EXTENDING
EITHER S CENTRAL CANADA OR THE NORTHERN TO CENTRAL PLAINS. LOOK FOR
THE RIDGE TO BE SUPPRESSED WEDNESDAY AFTERNOON INTO THURSDAY. A W-E
ORIENTED COLD FRONT SET UP JUST N OF LAKE SUPERIOR ACROSS ONTARIO
WILL SINK ACROSS LAKE SUPERIOR WEDNESDAY AFTERNOON...AND UPPER MI
WEDNESDAY NIGHT BEFORE PUSHING ACROSS WI AND LOWER MI DURING THE DAY
THURSDAY.

WEDNESDAY WILL BE DRY...AND EVEN WITH GOOD MIXING WINDS SHOULD STAY
FAIRLY LIGHT AS YOU NEED TO GO ABOVE 500MB TO GET ANYTHING ABOVE
15KTS. THE COLD FRONT SINKING THROUGH WILL BRING SOME MOISTURE TO
THE AREA...BUT IT/S NOT LOOKING LIKE MUCH MORE THAN CLOUD COVER.
MOST MODELS DO SHOW A BETTER CHANCE FOR AT LEAST SPRINKLES JUST S OF
MENOMINEE AND LOWER MI THURSDAY AFTERNOON...BUT NOTHING FOR UPPER
MI. THIS IS HANDLES WELL IN OUR PREVIOUS FCST...SO LIMITED CHANGES
WILL BE NEEDED. ANY REAL WARM UP WILL HAVE TO WAIT UNTIL THE
WEEKEND...AS COOL N WINDS OFF LAKE SUPERIOR AND 850MB TEMPS ON
THURSDAY HOVERING AROUND 2C. 850MB TEMPS MAY GET DOWN TO -3 OR -4C E
BY 12Z FRIDAY...LEADING TO ANOTHER CHILLY MORNING. OVERNIGHT LOWS IN
THE 30S WILL BE COMMON BOTH WEDNESDAY NIGHT AND THURSDAY NIGHT.

SATURDAY WILL BE A TRANSITION DAY AS THE CANADIAN HIGH EDGES TO THE
SE AND SLIGHTLY WARMER AIR MOVES IN. IT WILL END UP BEING THE
WARMEST DAY THIS WEEK WITH HIGHS NEAR NORMAL /60S TO AROUND 70F/.

THE 500MB RIDGE WILL STRENGTHEN OVER THE CWA SUNDAY AND MONDAY AS
THE SFC RIDGE LINGERS. THE GFS IS A BIT MORE AGGRESSIVE WITH THE MAIN
500MB TROUGH DIGGING BACK INTO THE UPPER GREAT LAKES ON
MONDAY...LEADING TO A STRONGER SYSTEM OVERALL. THE APEX OF THE RIDGE
WILL BE NEARBY AROUND 12Z MONDAY...WITH SW FLOW RETURNING AHEAD OF A
SFC LOW NEARING FROM THE SW. THE BEST CHANCE OF PRECIP IN THIS
LONGER TERM PERIOD WILL LIKELY HOLD OFF UNTIL THE DAYTIME HOURS
MONDAY. THERE IS STILL SOME UNCERTAINTY AS TO WHETHER THE BEST
CHANCE WILL BE OVER THE N OR S...DEPENDING ON THE TRACK/STRENGTH OF
THE SFC LOW AND NEARING SHORTWAVE ENERGY.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 128 PM EDT TUE MAY 19 2015

AS HIGH PRESSURE BUILDS TOWARD THE AREA...EXPECT VFR CONDITIONS WITH
MUCH DRIER AIR AND MIXING AT KIWD AND INTO KCMX AND KSAW MID TO LATE
AFTERNOON AS NNW GRADUALLY DIMINISH.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 506 AM EDT TUE MAY 19 2015

LOW PRES CENTERED OVER QUEBEC WILL CONTINUE TO LIFT NE TODAY AS HIGH
PRES GRADUALLY BUILDS IN FM THE WEST. NNW WINDS TO 20 TO 30 KNOTS
(HIGHEST EAST HALF) THIS MORNING WILL DIMINISH W TO E THIS
AFTERNOON/TONIGHT AS THE HIGH BUILDS IN FM THE WEST DECREASING THE
PRES GRADIENT. WED THRROUGH SAT...WINDS WILL BE UNDER 20KT AS SFC
HIGH PRES REMAINS IN CONTROL THROUGH MUCH OF THE PERIOD.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...VOSS
LONG TERM...KF
AVIATION...- NONE -
MARINE...VOSS




AREA FORECAST DISCUSSION

NWS RALEIGH NC

 318 PM EDT TUE MAY 19 2015

.SYNOPSIS...A COLD FRONT WILL MOVE ACROSS CENTRAL NORTH CAROLINA
TONIGHT...AND THEN STALL OVER SOUTH CAROLINA ON WEDNESDAY.  THE
FRONT WILL THEN RETREAT NORTH IN ADVANCE OF AN AREA OF LOW PRESSURE
THAT WILL CROSS THE CAROLINAS ON THURSDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 225 PM TUESDAY...

SCATTERED SHOWERS AND ISOLD TSTMS HAVE BROKEN OUT ACROSS PARTS OF
CENTRAL NC AS EXPECTED...WITH ACTIVITY EXPECTED TO CONTINUE TO
EXPAND AND MOVE EAST THROUGH THE REMAINDER OF THE AFTERNOON. LATEST
MESOANALYSIS STILL SHOWS THE BEST MOISTURE AND INSTABILITY LOCATED
ACROSS OUR EASTERN ZONES...AND SUGGESTS THAT SHOWER/TSTM COVERAGE
SHOULD INCREASE AS THEY EVOLVE EASTWARD LATER THIS AFTERNOON.
ANOTHER NOTABLE FEATURE IS A MID LEVEL VORT CURRENTLY MOVING E
ACROSS NE SC. THIS FEATURE MAY AID THE DEVELOPMENT AND MAINTENANCE
OF SHOWER/TSTM ACTIVITY ACROSS OUR SE ZONES AS IT MOVES EAST THE
REST OF THIS AFTERNOON. OTHERWISE...GIVEN WEAK MID-LEVEL LAPSE RATES
AND WEAK SHEAR...CELL INTENSITY SHOULD BE LIMITED...BUT STILL
CAPABLE OF PRODUCING BRIEF INTENSE DOWNPOURS GIVEN THE ABUNDANT
MOISTURE AND ABOVE-CLIMO PWAT VALUES IN PLACE ACROSS THE AREA.
SHOWER/TSTM ACTIVITY IS THEN EXPECTED TO DIMINISH AND MOVE EAST
TOWARD THE COAST LATER THIS EVENING.

OVERNIGHT...THE COLD FRONT WHICH IS CURRENTLY EXTENDING FROM
PITTSBURGH TO NASHVILLE TO MEMPHIS WILL MOVE S AND E AND ACROSS OUR
CWA. LATEST HRRR SUGGESTS AN ISOLD SHOWER CAN`T BE RULED OUT WITH
PASSAGE OF THE FRONT...BUT MOST PLACES WILL REMAIN DRY AS THE FRONT
MOVES ACROSS. MORE LIKELY WILL BE THE FORMATION OF SOME FOG...ESP
ACROSS AREAS THAT RECEIVE HEAVIER RAINFALL THIS AFTERNOON AND
EVENING. LOW TEMPS WILL BE COOLEST ACROSS THE NW (AROUND 60) WHERE
THE FRONT WILL MOVE THROUGH EARLIER IN THE NIGHT...VERSUS OUR SE
ZONES WHERE THE FROPA WILL OCCUR LATER IN THE NIGHT AND THUS HAVE
LOW IN THE MID TO UPPER 60S.

&&

.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
AS OF 225 PM TUESDAY...

THE COLD FRONT WILL STALL TO OUR SOUTH ACROSS SC ON WEDNESDAY. THIS
WILL ALLOW DRIER AND SLIGHTLY COOLER AIR TO MOVE INTO OUR AREA FROM
THE NW. AS SUCH...LOOK FOR FAIR WEATHER WITH HIGHS FROM THE MID 80S
NORTH TO UPPER 80S SOUTH.

WEDNESDAY NIGHT...A SHORT WAVE OVER THE MISS VALLEY WILL MOVE EAST
AND INDUCE A LOW PRESSURE WAVE ALONG THE OLD BOUNDARY TO OUR SOUTH.
THERE ARE STILL MODEL DIFFERENCES REGARDING WHERE (PARTICULARLY HOW
FAR NORTH) THAT WAVE WILL SET UP...BUT EITHER WAY IT APPEARS THAT A
FEW SHOWERS WILL BE POSSIBLE ACROSS OUR PIEDMONT ZONES LATER
OVERNIGHT. LOWS WILL RANGE FROM AROUND 60 NW TO MID 60S SE.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
AS OF 315 PM TUESDAY...

THURSDAY TROUGH FRIDAY NIGHT: A QUICK MOVING S/W DISTURBANCE IS
EXPECTED TO MOVE FROM THE PLAINS TO OFF THE MID-ATLANTIC/NORTHEAST
U.S. COAST BY FRIDAY MORNING... SPREADING SHOWERS AND SOME STORMS
ACROSS CENTRAL ON THURSDAY. WHILE THE DISTURBANCE WILL TRACK JUST TO
OUR NORTH...AN AREA OF LOW PRESSURE IN RESPONSE WILL DEVELOP/DEEPEN
ALONG THE OLD FRONTAL ZONE NEAR THE NC/SC BORDER... THEN LIFT NORTH
AND EASTWARD ON THURSDAY NIGHT INTO FRIDAY. THIS SHOULD BRING A WIDE
RANGE IN TEMPS ACROSS CENTRAL NC ON THURSDAY... WITH THE POTENTIAL
FOR SOME ROTATING STORMS NEAR THE BOUNDARY... AS DEEP LAYER SHEAR IS
EXPECTED TO INCREASE TO 30 TO 35 KTS WITH A BACKED SURFACE FLOW AS
THE SURFACE APPROACHES. HOWEVER... WITH THE POSSIBILITY OF ON GOING
SHOWERS AND WIDESPREAD CLOUD COVER THERE IS QUITE A BIT OF
UNCERTAINTY WRT HOW MUCH DESTABILIZATION WE WILL SEE IN THE
DEVELOPING WARM SECTOR. THUS...SPC HAS PLACED SOUTHEASTERN/EASTERN
PORTIONS OF CENTRAL NC IN A MARGINAL RISK FOR SEVERE STORMS. FOR NOW
WILL CONTINUE TO MENTION A THREAT FOR ISOLATED SEVERE STORMS ACROSS
OUR SE/E COUNTIES IN THE HWO FOR THURSDAY. WILL GO WITH HIGHS TEMPS
ON THURSDAY RANGING FROM THE UPPER 60S/NEAR 70 (MAYBE NOT COOL
ENOUGH EVEN) NEAR THE NC/VA BORDER TO LOWER TO MID 80S
SOUTH/SOUTHEAST.

THE PRIMARY SURFACE LOW IS EXPECTED TO LIFT OFF TO THE NORTHEAST
LATE THURSDAY NIGHT INTO FRIDAY... BRINGING A RETURN TO DRY AND
QUIET WEATHER... WITH CLEARING/SUNNY SKIES BY FRIDAY AFTERNOON
ONWARD AS SURFACE HIGH PRESSURE BUILDS INTO THE AREA FROM THE
NORTHWEST. EXPECT HIGHS ON FRIDAY WILL BE IN THE UPPER 70S TO LOWER
80S. LOWS FRIDAY MORNING WILL BE DEPENDENT ON THE AMOUNT OF CLEARING
AND ANY LINGERING COOL STABLE AIRMASS. FOR NOW WILL GO WITH LOWS
RANGING FROM THE 50S NORTH TO THE MID 60S SE. LOWS SATURDAY... WITH
SURFACE HIGH PRESSURE TO THE NORTH OF THE REGION... ARE EXPECTED TO
BE IN THE MID TO UPPER 50S.

SATURDAY THROUGH TUESDAY: SURFACE HIGH PRESSURE WILL MOVE ACROSS THE
REGION THIS WEEKEND AND OFFSHORE EARLY NEXT WEEK AS MID LEVEL
RIDGING BEGINS TO BUILD AGAIN. THIS WILL YIELD A WARMING TREND EACH
DAY FROM HIGHS IN THE UPPER 70S TO LOWER 80S ON SATURDAY TO THE
UPPER 80S TO LOWER 90S ON TUESDAY. LOWS WILL FOLLOW A SIMILAR
TREND... 50S THIS WEEKEND TO THE MID TO UPPER 60S BY TUESDAY
MORNING. DRY CONDITIONS ARE GENERALLY EXPECTED FOR THIS PERIOD...
WITH INCREASING CHANCES OF AT LEAST SOME ISOLATED OR WIDELY
SCATTERED SHOWERS AND STORMS BY TUESDAY AFTERNOON (BEST CHANCE
NORTHWEST) AS LOW LEVEL MOISTURE INCREASES IN RETURN FLOW.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
AS OF 225 PM TUESDAY...

SCATTERED SHOWERS AND TSTMS WILL BE POSSIBLE ACROSS MUCH OF CENTRAL
NC THROUGH THE REMAINDER OF THE AFTERNOON. THESE SHOWERS WILL
LOCALLY AND BRIEFLY REDUCE CIGS AND VSBY TO IFR OR MVFR. OUTSIDE OF
THESE SHOWERS/TSTMS...VFR CONDITIONS CAN BE EXPECTED. THE ACTIVITY
WILL WIND DOWN FROM WEST TO EAST THIS EVENING...ENDING AT INT/GSO BY
19/23Z...RDU BY 20/00Z...AND RWI/FAY BY 20/01Z. AREAS OF FOG WILL BE
POSSIBLE OVERNIGHT WHERE THE HEAVIEST RAIN OCCURS...BUT CONFIDENCE
RIGHT NOW IS STILL TOO LOW TO INCLUDE IN THE TAFS. WITH DRIER AIR
ARRIVING BEHIND THE FRONT...EXPECT VFR CONDITIONS DURING THE DAYTIME
WEDNESDAY.

OUTLOOK: AN AREA OF LOW PRESSURE WILL TRACK ACROSS THE CAROLINAS AND
RESULT IN A CHANCE OF SUB-VFR CEILINGS AND RAIN LATE WED NIGHT AND
EARLY THU...FOLLOWED BY SHOWERS AND STORMS THU AFTERNOON.

&&

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

&&

$$

SYNOPSIS...RAH
NEAR TERM...RAH
SHORT TERM...RAH
LONG TERM...RAH
AVIATION...RAH



AREA FORECAST DISCUSSION

NWS RALEIGH NC

 225 PM EDT TUE MAY 19 2015

.SYNOPSIS...A COLD FRONT WILL MOVE ACROSS CENTRAL NORTH CAROLINA
TONIGHT...AND THEN STALL OVER SOUTH CAROLINA ON WEDNESDAY.  THE
FRONT WILL THEN RETREAT NORTH IN ADVANCE OF AN AREA OF LOW PRESSURE
THAT WILL CROSS THE CAROLINAS ON THURSDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 225 PM TUESDAY...

SCATTERED SHOWERS AND ISOLD TSTMS HAVE BROKEN OUT ACROSS PARTS OF
CENTRAL NC AS EXPECTED...WITH ACTIVITY EXPECTED TO CONTINUE TO
EXPAND AND MOVE EAST THROUGH THE REMAINDER OF THE AFTERNOON. LATEST
MESOANALYSIS STILL SHOWS THE BEST MOISTURE AND INSTABILITY LOCATED
ACROSS OUR EASTERN ZONES...AND SUGGESTS THAT SHOWER/TSTM COVERAGE
SHOULD INCREASE AS THEY EVOLVE EASTWARD LATER THIS AFTERNOON.
ANOTHER NOTABLE FEATURE IS A MID LEVEL VORT CURRENTLY MOVING E
ACROSS NE SC. THIS FEATURE MAY AID THE DEVELOPMENT AND MAINTENANCE
OF SHOWER/TSTM ACTIVITY ACROSS OUR SE ZONES AS IT MOVES EAST THE
REST OF THIS AFTERNOON. OTHERWISE...GIVEN WEAK MID-LEVEL LAPSE RATES
AND WEAK SHEAR...CELL INTENSITY SHOULD BE LIMITED...BUT STILL
CAPABLE OF PRODUCING BRIEF INTENSE DOWNPOURS GIVEN THE ABUNDANT
MOISTURE AND ABOVE-CLIMO PWAT VALUES IN PLACE ACROSS THE AREA.
SHOWER/TSTM ACTIVITY IS THEN EXPECTED TO DIMINISH AND MOVE EAST
TOWARD THE COAST LATER THIS EVENING.

OVERNIGHT...THE COLD FRONT WHICH IS CURRENTLY EXTENDING FROM
PITTSBURGH TO NASHVILLE TO MEMPHIS WILL MOVE S AND E AND ACROSS OUR
CWA. LATEST HRRR SUGGESTS AN ISOLD SHOWER CAN`T BE RULED OUT WITH
PASSAGE OF THE FRONT...BUT MOST PLACES WILL REMAIN DRY AS THE FRONT
MOVES ACROSS. MORE LIKELY WILL BE THE FORMATION OF SOME FOG...ESP
ACROSS AREAS THAT RECEIVE HEAVIER RAINFALL THIS AFTERNOON AND
EVENING. LOW TEMPS WILL BE COOLEST ACROSS THE NW (AROUND 60) WHERE
THE FRONT WILL MOVE THROUGH EARLIER IN THE NIGHT...VERSUS OUR SE
ZONES WHERE THE FROPA WILL OCCUR LATER IN THE NIGHT AND THUS HAVE
LOW IN THE MID TO UPPER 60S.

&&

.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
AS OF 225 PM TUESDAY...

THE COLD FRONT WILL STALL TO OUR SOUTH ACROSS SC ON WEDNESDAY. THIS
WILL ALLOW DRIER AND SLIGHTLY COOLER AIR TO MOVE INTO OUR AREA FROM
THE NW. AS SUCH...LOOK FOR FAIR WEATHER WITH HIGHS FROM THE MID 80S
NORTH TO UPPER 80S SOUTH.

WEDNESDAY NIGHT...A SHORT WAVE OVER THE MISS VALLEY WILL MOVE EAST
AND INDUCE A LOW PRESSURE WAVE ALONG THE OLD BOUNDARY TO OUR SOUTH.
THERE ARE STILL MODEL DIFFERENCES REGARDING WHERE (PARTICULARLY HOW
FAR NORTH) THAT WAVE WILL SET UP...BUT EITHER WAY IT APPEARS THAT A
FEW SHOWERS WILL BE POSSIBLE ACROSS OUR PIEDMONT ZONES LATER
OVERNIGHT. LOWS WILL RANGE FROM AROUND 60 NW TO MID 60S SE.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 335 AM TUESDAY...

A WAVE OF LOW PRESSURE MOVING ALONG THE FRONTAL ZONE DRAPED ACROSS
THE MID-SOUTH AND CAROLINAS IS FORECAST TO SLOWLY DEEPEN AS IT MOVES
SOMEWHERE NEAR THE NC/SC ON THURSDAY AND THEN OFF THE NC COAST
THURSDAY NIGHT.  THE GFS CONTINUES TO BE A WEAKER AND SOUTHERN
OUTLIER WHEN IT COMES TO THE LOCATION OF THE FRONT AND TRACK OF THE
WAVE...SO WILL LEAN TOWARD THE ECMWF/NAM...WHICH HAVE SUPPORT FROM
THE ECMWF ENSEMBLE.  THE FORCING ALOFT WILL BE MOSTLY WEAK WITH THIS
SYSTEM AS THE LEAD SOUTHERN STREAM SHORTWAVE DEAMPLIFIES OVER THE
MIDWEST AND MERGES WITH A TRAILING NORTHERN STREAM WAVE THAT PASSES
TO OUR NORTH THURSDAY AFTERNOON.  HOWEVER...WEAK HEIGHT FALLS AND
GOOD LOW-LEVEL CONVERGENCE NEAR THE FRONTAL ZONE/SFC LOW WILL LEAD
TO SCATTERED SHOWERS/STORMS THAT MAY BECOME NUMEROUS OVER THE
COASTAL PLAIN THURSDAY AFTERNOON/EVENING PENDING DESTABILIZATION AS
DEWPOINTS CREEP BACK INTO THE UPPER 60S.  IF MORNING SHOWERS AND/OR
CLOUDS DONT LIMIT HEATING TOO MUCH THEN SOME WEAK CAPE MAY DEVELOP.
A CONDITIONAL SEVERE THREAT MAY THEN EXIST GIVEN 30-35KT OF MID-
LEVEL FLOW AND  BACKED LOW-LEVEL FLOW AHEAD OF THE SURFACE
LOW....MAINLY EAST OF I-95 WHERE THE THE PARAMETER SPACE FOR SOME
ROTATING STORMS WOULD BE MAXIMIZED. THE DEEPER NAM SHOWS BETTER
POTENTIAL THAN THE ECMWF...SO AT THIS TIME THE SEVERE THREAT IS
LIKELY LOW BUT WORTH WATCHING.  HIGHS WILL RANGE FROM THE MID 70S
NORTH TO LOW OR MID 80S SOUTH DEPENDING ON HOW ROBUST MID CLOUDS ARE
AS THEY ADVECT IN FROM THE WEST EARLY IN THE DAY.

PRECIP WILL COME TO AN END THURSDAY NIGHT AND EARLY FRIDAY AS THE
SURFACE LOW MOVES OFF THE COAST AND A MUCH MORE STABLE AIRMASS
FILTERS OVER THE REGION...COURTESY OF A RELATIVELY STRONG HIGH
PRESSURE THAT WILL BUILD ACROSS THE GREAT LAKES.  THICKNESSES DROP
OFF SIGNIFICANTLY FRIDAY AND SUGGEST HIGHS IN THE MID 70S TO LOW 80S
FRIDAY AND SATURDAY.  THE PATTERN WILL THEN SHIFT BACK TO TROUGHING
OUT WEST AND A SUB-TROPICAL RIDGE OVER THE SOUTHEAST US...WHICH
WILL BRING TEMPS BACK TO AND ABOVE NORMAL BY EARLY NEXT WEEK.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
AS OF 225 PM TUESDAY...

SCATTERED SHOWERS AND TSTMS WILL BE POSSIBLE ACROSS MUCH OF CENTRAL
NC THROUGH THE REMAINDER OF THE AFTERNOON. THESE SHOWERS WILL
LOCALLY AND BRIEFLY REDUCE CIGS AND VSBY TO IFR OR MVFR. OUTSIDE OF
THESE SHOWERS/TSTMS...VFR CONDITIONS CAN BE EXPECTED. THE ACTIVITY
WILL WIND DOWN FROM WEST TO EAST THIS EVENING...ENDING AT INT/GSO BY
19/23Z...RDU BY 20/00Z...AND RWI/FAY BY 20/01Z. AREAS OF FOG WILL BE
POSSIBLE OVERNIGHT WHERE THE HEAVIEST RAIN OCCURS...BUT CONFIDENCE
RIGHT NOW IS STILL TOO LOW TO INCLUDE IN THE TAFS. WITH DRIER AIR
ARRIVING BEHIND THE FRONT...EXPECT VFR CONDITIONS DURING THE DAYTIME
WEDNESDAY.

OUTLOOK: AN AREA OF LOW PRESSURE WILL TRACK ACROSS THE CAROLINAS AND
RESULT IN A CHANCE OF SUB-VFR CEILINGS AND RAIN LATE WED NIGHT AND
EARLY THU...FOLLOWED BY SHOWERS AND STORMS THU AFTERNOON.

&&

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

&&

$$

SYNOPSIS...RAH
NEAR TERM...RAH
SHORT TERM...RAH
LONG TERM...22
AVIATION...RAH



AREA FORECAST DISCUSSION

NWS STATE COLLEGE PA

 531 PM EDT TUE MAY 19 2015

.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS CENTRAL PENNSYLVANIA TODAY WITH A
MARGINAL/ISOLATED SEVERE WEATHER RISK FROM THE EASTERN COAL REGION
INTO THE POCONOS. A COOLER AND MAINLY DRY WEATHER PATTERN WITH
NEAR TO BELOW NORMAL TEMPERATURES WILL GRIP THE REGION FROM
WEDNESDAY INTO THE WEEKEND...FOLLOWED BY A GRADUAL WARMING TREND
WITH UNSETTLED CONDITIONS THROUGH EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
WINDS NOW GUSTY WITH MIXING FAIRLY DEEP IN THE CENTRAL MTNS WHERE
SUN HAS BEEN OUT LONGEST. ML CAPES ABOVE 500 THERE NOW. COLD
FRONT ONLY THROUGH ABOUT 5 COUNTIES AT THIS POINT AND TAKING IT/S
TIME. CAPES RISING IN THE SUSQ VALLEY WHERE DEWPOINTS ARE STILL
VERY HIGH. OLD BOUNDARY LYING OVER OR EVEN JUST TO THE WEST OF THE
MAIN STEM SUSQ RIVER AT 1 PM. HRRR AND RUC ARE IN AGREEMENT THAT
SHRA AND WIDELY SCT TSRA WILL FORM IN THE EASTERN COUNTIES IN THE
MIDDLE OF THE AFTERNOON...BUT TAKE UNTIL SUNSET FOR ALL OF THEM TO
GET TO THE EAST OF THE CWA. WINDS ALOFT WILL HELP MOVE THESE SCT
SHRA ALONG AND FLOODING WORRIES VERY LOW.

AS THE SUN SETS AND SHOWERS EXIT/WANE CONCURRENTLY...THE REST OF
THE AREA SHOULD BE MAINLY CLEAR. BUT THE LOWER CLOUDS OVER THE
UPPER GREAT LAKES WILL BEGIN TO SLIDE INTO THE NW. THESE CLOUDS
WILL TRY TO COVER THE NWRN HALF OF THE AREA. SCT CLOUDS MAY MAKE
IT DOWN THE HILLS INTO THE SE BY THE END OF THE NIGHT BUT THE
DOWNSLOPE WILL HELP TO DRY THEM UP. CLOUDS IN THE NW WILL HELP
KEEP TEMPS UP IN THE U30S ON THE NW PLATEAU AND OTHER AREAS WILL
FALL TO THE 40S AND L50S. URBAN AREAS IN THE SE MAY HOLD NEAR 55F
DESPITE THE CLEAR SKY DUE TO THE WINDS STAYING UP FOR MOST/ALL OF
THE NIGHT AND KEEPING THE BLYR WELL-MIXED.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/...
PRESSURE RISES AND SUBSIDENCE MOVES IN FROM THE NW BUT WINDS WILL
STILL BE NW AND RATHER GUSTY DURING THE DAY ON WED AS CENTER OF
SFC HIGH STAYS WELL TO THE WEST. MIXING SHOULD ALLOW GUSTS INTO
THE 20S OR EVEN NEAR 30 MPH. MAXES WILL BE MUCH COOLER THAN
TUES...BUT THE MID/LATE MAY SUN/HEATING WILL ALLOW US TO MIX WELL
ABOVE 8H TEMPS. SO EVEN THOUGH MORNING 8H TEMPS WILL BE -2C IN THE
NRN TIER AND ONLY +2C IN THE SRN TIER...WE SHOULD STILL GET BACK
TO THE M50S N AND NEAR 70F IN THE SERN CITIES.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
THE MODELS SHOW A SHORTWAVE TROUGH MOVING QUICKLY ESEWD FROM THE
UPPER GREAT LAKES THROUGH THE CENTRAL APPALACHIANS AND NORTHERN
MID ATLANTIC STATES THU-FRI WITH PLENTY OF CLOUDS AND SOME
SHOWERS POSSIBLE ON THU. A WEAK SFC LOW IS FCST TO EMERGE OFF THE
CAROLINAS INTO FRIDAY WITH SOME SPREAD IN THE GUIDANCE...OWING TO
VARIABILITY IN THE HANDLING OF THE PARENT SHORTWAVE. A SECONDARY
COLD FRONT SHOULD CROSS THE AREA ON FRIDAY FOLLOWED BY A
REINFORCING SHOT OF COOL AIR. CONFIDENCE REMAINS ON THE LOW SIDE
FOR FROST THU MORNING IN THE NORTH AS THE PATTERN DOES NOT LOOK
FAVORABLE OR CONDUCIVE.

CONFIDENCE IN FROST POTENTIAL IS MUCH HIGHER ON SATURDAY MORNING
OVER THE NORTH-CNTRL ZONES WITH A LARGE AREA OF HIGH PRESSURE
FCST TO SETTLE OVER CENTRAL PA. MAINTAINED FROST WORDING IN SOME
NORTHERN ZONES. DRY WX SHOULD HOLD ON UNTIL EARLY NEXT WEEK AS
THE UPPER RIDGE BUILDS AGAIN OVER THE ERN U.S.

AN E-W FRONTAL BOUNDARY LOOKS TO BECOME A FOCUS FOR PCPN MON-TUE
AS IT PIVOTS AND LIFTS NWD IN A SIMILAR FASHION TO THIS PAST
WEEKEND. ALL GUIDANCE POINTS TO A GRADUAL WARMING TREND OVER THE
WEEKEND...WITH EVEN MILDER AND MORE MUGGY CONDITIONS STARTING
MEMORIAL DAY AND CONTINUING INTO NEXT WEEK.

&&

.AVIATION /22Z TUESDAY THROUGH SUNDAY/...

THE COLD FRONT HAS CLEARED MY EASTERN ZONES LEAVING BEHIND VFR
CONDITIONS AND A GUSTY WNW WIND.

MOST OF THE REGION WILL REMAIN VFR INTO WEDNESDAY...WITH THE
POSSIBLE EXCEPTION OF HIGHER ELEVATIONS FROM JOHNSTOWN INTO THE
NORTHERN MOUNTAINS WHERE CEILINGS MAY DROP INTO THE MVFR CATEGORY
FOR A TIME LATER TONIGHT THROUGH MID MORNING TOMORROW.



OUTLOOK...

WED-FRI...NO SIG WX.

SUN...MAINLY VFR...MVFR POSS IN SHRA/TSRA.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...DANGELO
LONG TERM...RXR/STEINBUGL
AVIATION...DANGELO/LA CORTE




AREA FORECAST DISCUSSION

NWS STATE COLLEGE PA

 400 PM EDT TUE MAY 19 2015

.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS CENTRAL PENNSYLVANIA TODAY WITH A
MARGINAL/ISOLATED SEVERE WEATHER RISK FROM THE EASTERN COAL REGION
INTO THE POCONOS. A COOLER AND MAINLY DRY WEATHER PATTERN WITH
NEAR TO BELOW NORMAL TEMPERATURES WILL GRIP THE REGION FROM
WEDNESDAY INTO THE WEEKEND...FOLLOWED BY A GRADUAL WARMING TREND
WITH UNSETTLED CONDITIONS THROUGH EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
WINDS NOW GUSTY WITH MIXING FAIRLY DEEP IN THE CENTRAL MTNS WHERE
SUN HAS BEEN OUT LONGEST. ML CAPES ABOVE 500 THERE NOW. COLD
FRONT ONLY THROUGH ABOUT 5 COUNTIES AT THIS POINT AND TAKING IT/S
TIME. CAPES RISING IN THE SUSQ VALLEY WHERE DEPOINTS ARE STILL
VERY HIGH. OLD BOUNDARY LYING OVER OR EVEN JUST TO THE WEST OF THE
MAIN STEM SUSQ RIVER AT 1 PM. HRRR AND RUC ARE IN AGREEMENT THAT
SHRA AND WIDELY SCT TSRA WILL FORM IN THE EASTERN COUNTIES IN THE
MIDDLE OF THE AFTERNOON...BUT TAKE UNTIL SUNSET FOR ALL OF THEM TO
GET TO THE EAST OF THE CWA. WINDS ALOFT WILL HELP MOVE THESE SCT
SHRA ALONG AND FLOODING WORRIES VERY LOW.

AS THE SUN SETS AND SHOWERS EXIT/WANE CONCURRENTLY...THE REST OF
THE AREA SHOULD BE MAINLY CLEAR. BUT THE LOWER CLOUDS OVER THE
UPPER GREAT LAKES WILL BEGIN TO SLIDE INTO THE NW. THESE CLOUDS
WILL TRY TO COVER THE NWRN HALF OF THE AREA. SCT CLOUDS MAY MAKE
IT DOWN THE HILLS INTO THE SE BY THE END OF THE NIGHT BUT THE
DOWNSLOPE WILL HELP TO DRY THEM UP. CLOUDS IN THE NW WILL HELP
KEEP TEMPS UP IN THE U30S ON THE NW PLATEAU AND OTHER AREAS WILL
FALL TO THE 40S AND L50S. URBAN AREAS IN THE SE MAY HOLD NEAR 55F
DESPITE THE CLEAR SKIY DUE TO THE WINDS STAYING UP FOR MOST/ALL
OF THE NIGHT AND KEEPING THE BLYR WELL-MIXED.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/...
PRESSURE RISES AND SUBSIDENCE MOVES IN FROM THE NW BUT WINDS WILL
STILL BE NW AND RATHER GUSTY DURING THE DAY ON WED AS CENTER OF
SFC HIGH STAYS WELL TO THE WEST. MIXING SHOULD ALLOW GUSTS INTO
THE 20S OR EVEN NEAR 30 MPH. MAXES WILL BE MUCH COOLER THAN
TUES...BUT THE MID/LATE MAY SUN/HEATING WILL ALLOW US TO MIX WELL
ABOVE 8H TEMPS. SO EVEN THOUGH MORNING 8H TEMPS WILL BE -2C IN THE
NRN TIER AND ONLY +2C IN THE SRN TIER...WE SHOULD STILL GET BACK
TO THE M50S N AND NEAR 70F IN THE SERN CITIES.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
THE MODELS SHOW A SHORTWAVE TROUGH MOVING QUICKLY ESEWD FROM THE
UPPER GREAT LAKES THROUGH THE CENTRAL APPALACHIANS AND NORTHERN
MID ATLANTIC STATES THU-FRI WITH PLENTY OF CLOUDS AND SOME
SHOWERS POSSIBLE ON THU. A WEAK SFC LOW IS FCST TO EMERGE OFF THE
CAROLINAS INTO FRIDAY WITH SOME SPREAD IN THE GUIDANCE...OWING TO
VARIABILITY IN THE HANDLING OF THE PARENT SHORTWAVE. A SECONDARY
COLD FRONT SHOULD CROSS THE AREA ON FRIDAY FOLLOWED BY A
REINFORCING SHOT OF COOL AIR. CONFIDENCE REMAINS ON THE LOW SIDE
FOR FROST THU MORNING IN THE NORTH AS THE PATTERN DOES NOT LOOK
FAVORABLE OR CONDUCIVE.

CONFIDENCE IN FROST POTENTIAL IS MUCH HIGHER ON SATURDAY MORNING
OVER THE NORTH-CNTRL ZONES WITH A LARGE AREA OF HIGH PRESSURE
FCST TO SETTLE OVER CENTRAL PA. MAINTAINED FROST WORDING IN SOME
NORTHERN ZONES. DRY WX SHOULD HOLD ON UNTL EARLY NEXT WEEK AS THE
UPPER RIDGE BUILDS AGAIN OVER THE ERN U.S.

AN E-W FRONTAL BOUNDARY LOOKS TO BECOME A FOCUS FOR PCPN MON-TUE
AS IT PIVOTS AND LIFTS NWD IN A SIMILAR FASHION TO THIS PAST
WEEKEND. ALL GUIDANCE POINTS TO A GRADUAL WARMING TREND OVER THE
WEEKEND...WITH EVEN MILDER AND MORE MUGGY CONDITIONS STARTING
MEMORIAL DAY AND CONTINUING INTO NEXT WEEK.

&&

.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
COLD FRONT MOVING RATHER SLOWLY THIS AFTN. IT MAY NOT CLEAR LNS
BEFORE 00Z. THUS...SHOWERS AND SCT THUNDERSTORMS ARE EXPECTED TO
DEVELOP - MAINLY ALONG AND TO THE EAST OF IPT AND MDT. HIGH
PRESSURE THEN MOVES IN. BUT CLOUD DECK UNDER UPPER LOW WILL SLIDE
ACROSS THE AREA FROM NW-SE LATER THIS EVENING AND OVERNIGHT.
SOME STRATUS CLOUDS WILL LINGER INTO THE MORNING...BUT BREAK UP
AND LIFT TO JUST HARMLESS CU. CIGS SHOULD REMAIN MVFR
TONIGHT...BUT COULD DIP TO IFR AT BFD AND JST. WILL LEAVE THEM
LOWER-END MVFR FOR NOW.

OUTLOOK...

WED...NO SIG WX.
WED NIGHT-THURS...MAINLY VFR. SHRA POSS ESP S.
THURS NIGHT-FRI...NO SIG WX.
SUN...MAINLY VFR...MVFR POSS IN SHRA/TSRA.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...DANGELO
LONG TERM...RXR/STEINBUGL
AVIATION...DANGELO




AREA FORECAST DISCUSSION

NWS STATE COLLEGE PA

 113 PM EDT TUE MAY 19 2015

.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS CENTRAL PENNSYLVANIA TODAY WITH A
MARGINAL/ISOLATED SEVERE WEATHER RISK FROM THE EASTERN COAL REGION
INTO THE POCONOS. A COOLER AND MAINLY DRY WEATHER PATTERN WITH
NEAR TO BELOW NORMAL TEMPERATURES WILL GRIP THE REGION FROM
WEDNESDAY INTO THE WEEKEND...FOLLOWED BY A GRADUAL WARMING TREND
WITH UNSETTLED CONDITIONS THROUGH EARLY NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
WINDS NOW GUSTY WITH MIXING FAIRLY DEEP IN THE CENTRAL MTNS WHERE
SUN HAS BEEN OUT LONGEST. ML CAPES ABOVE 500 THERE NOW. COLD
FRONT ONLY THROUGH ABOUT 5 COUNTIES AT THIS POINT AND TAKING IT/S
TIME. CAPES RISING IN THE SUSQ VALLEY WHERE DEPOINTS ARE STILL
VERY HIGH. OLD BOUNDARY LYING OVER OR EVEN JUST TO THE WEST OF THE
MAIN STEM SUSQ RIVER AT 1 PM. HRRR AND RUC ARE IN AGREEMENT THAT
SHRA AND WIDELY SCT TSRA WILL FORM IN THE EASTERN COUNTIES IN THE
MIDDLE OF THE AFTERNOON...BUT TAKE UNTIL SUNSET FOR ALL OF THEM TO
GET TO THE EAST OF THE CWA. WINDS ALOFT WILL HELP MOVE THESE SCT
SHRA ALONG AND FLOODING WORRIES VERY LOW.

AS THE SUN SETS AND SHOWERS EXIT/WANE CONCURRENTLY...THE REST OF
THE AREA SHOULD BE MAINLY CLEAR. BUT THE LOWER CLOUDS OVER THE
UPPER GREAT LAKES WILL BEGIN TO SLIDE INTO THE NW. THESE CLOUDS
WILL TRY TO COVER THE NWRN HALF OF THE AREA. SCT CLOUDS MAY MAKE
IT DOWN THE HILLS INTO THE SE BY THE END OF THE NIGHT BUT THE
DOWNSLOPE WILL HELP TO DRY THEM UP. CLOUDS IN THE NW WILL HELP
KEEP TEMPS UP IN THE U30S ON THE NW PLATEAU AND OTHER AREAS WILL
FALL TO THE 40S AND L50S. URBAN AREAS IN THE SE MAY HOLD NEAR 55F
DESPITE THE CLEAR SKIY DUE TO THE WINDS STAYING UP FOR MOST/ALL
OF THE NIGHT AND KEEPING THE BLYR WELL-MIXED.

&&

.SHORT TERM /WEDNESDAY/...
PRESSURE RISES AND SUBSIDENCE MOVES IN FROM THE NW BUT WINDS WILL
STILL BE NW AND RATHER GUSTY DURING THE DAY ON WED AS CENTER OF
SFC HIGH STAYS WELL TO THE WEST. MIXING SHOULD ALLOW GUSTS INTO
THE 20S OR EVEN NEAR 30 MPH. MAXES WILL BE MUCH COOLER THAN
TUES...BUT THE MID/LATE MAY SUN/HEATING WILL ALLOW US TO MIX WELL
ABOVE 8H TEMPS. SO EVEN THOUGH MORNING 8H TEMPS WILL BE -2C IN THE
NRN TIER AND ONLY +2C IN THE SRN TIER...WE SHOULD STILL GET BACK
TO THE M50S N AND NEAR 70F IN THE SERN CITIES.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
THE MODELS SHOW A SHORTWAVE TROUGH MOVING QUICKLY ESEWD FROM THE
UPPER GREAT LAKES THROUGH CENTRAL APPALACHIANS AND NORTHERN MID
ATLANTIC STATES THU-FRI WITH SOME SHOWERS POSSIBLE ON THU. A SFC
LOW IS FCST TO EMERGE OFF THE CAROLINAS INTO FRIDAY WITH SOME
SPREAD IN THE GUIDANCE...OWING TO VARIABILITY IN THE HANDLING OF
THE PARENT SHORTWAVE. A SECONDARY COLD FRONT SHOULD CROSS THE AREA
ON FRIDAY FOLLOWED BY ANOTHER SHOT OF COOL AIR. CONFIDENCE REMAINS
ON THE LOW SIDE FOR FROST THU MORNING IN THE NORTH AS THE PATTERN
DOES NOT LOOK FAVORABLE OR CONDUCIVE.

CONFIDENCE IN FROST POTENTIAL IS MUCH HIGHER ON SATURDAY MORNING
OVER THE NORTH-CNTRL ZONES WITH A LARGE AREA OF HP FCST TO SETTLE
OVER CENTRAL PA. WILL ADD FROST WORDING TO THE HWO FOR THE 3 ZONES
THAT ARE STILL NOT IN THE GROWING SEASON /MCKEAN-POTTER-ELK/. DRY
WX SHOULD HOLD ON UNTL EARLY NEXT WEEK AS THE UPPER RIDGE BUILDS
AGAIN OVER THE ERN U.S. AN E-W FRONTAL BOUNDARY COULD BE A FOCUS
FOR PCPN AS IT PIVOTS AND LIFTS NWD IN A SIMILAR FASHION TO THIS
PAST WEEKEND. CLOSELY FOLLOWED THE ROBUST NATIONAL SUPERBLEND
PROTOTYPE GUIDANCE FOR TEMPERATURES WHICH FAVORS A GRADUAL
WARMING TREND FOR THE AREA BEYOND THE END OF THE PERIOD.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
COLD FRONT MOVING RATHER SLOWLY THIS AFTN. IT MAY NOT CLEAR LNS
BEFORE 00Z. THUS...SHOWERS AND SCT THUNDERSTORMS ARE EXPECTED TO
DEVELOP - MAINLY ALONG AND TO THE EAST OF IPT AND MDT. HIGH
PRESSURE THEN MOVES IN. BUT CLOUD DECK UNDER UPPER LOW WILL SLIDE
ACROSS THE AREA FROM NW-SE LATER THIS EVENING AND OVERNIGHT.
SOME STRATUS CLOUDS WILL LINGER INTO THE MORNING...BUT BREAK UP
AND LIFT TO JUST HARMLESS CU. CIGS SHOULD REMAIN MVFR
TONIGHT...BUT COULD DIP TO IFR AT BFD AND JST. WILL LEAVE THEM
LOWER-END MVFR FOR NOW.

OUTLOOK...

WED...NO SIG WX.
WED NIGHT-THURS...MAINLY VFR. SHRA POSS ESP S.
THURS NIGHT-FRI...NO SIG WX.
SUN...MAINLY VFR...MVFR POSS IN SHRA/TSRA.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...DANGELO
LONG TERM...STEINBUGL
AVIATION...DANGELO




AREA FORECAST DISCUSSION

NWS SAN ANGELO TX

 602 PM CDT Tue May 19 2015

.AVIATION...
/00Z TAFS/

Scattered showers and thunderstorms are affecting mainly the KABI
TAF this evening, where a VCTS group was included. Elsewhere,
convection should remain isolated. Stratus will move back into all
of the TAF sites after 06z, resulting in MVFR/IFR ceilings. VFR
ceilings should return to all sites by late morning or early
afternoon Wednesday. A cold front will approach KABI around 17z,
then slowly move south. Scattered showers and thunderstorms will
be possible along and behind the front, along with a wind shift to
the north at 8 to 12 knots.

&&

.PREV DISCUSSION... /ISSUED 353 PM CDT Tue May 19 2015/

SHORT TERM...
(Today and Tonight)

..Flash flood Watch has been extended until 10 PM CDT tonight for
the Big Country, Concho Valley, and Heartland...

The atmosphere is unstable this afternoon with RUC SB CAPES of
4000 J/KG. Severe storms are certainly possible this afternoon and
evening with the very strong instability. Strong storms were
already developing in the Trans Pecos and eastern Permian basin,
where less stratus was bringing more heating and instability.
These will likely move eastward into the Concho Valley this
evening. Scattered showers and thunderstorms were also developing
from Robert Lee to Brownwood, then northward into the Big Country.

With saturated soil conditions from Wednesday storms, the flash
flood watch has been extended to 10 PM CDT to catch the evening
storms. While coverage is expected to be less, excessive rainfall
rates from slow moving storms will likely cause localized flash
flooding on saturated soils. The atmosphere remains very moist,
with the SPC mesoanalysis page indicating very high precipitable
waters of 1.5 to 1.7 inches, which could bring very efficient
rainfall production.

Wednesday, a cold front will move into the Big Country in the
afternoon, and through the rest of West Central Texas overnight.
The atmosphere will remain unstable, and the front may be a
focus for severe thunderstorm development and localized flooding.

04

LONG TERM...
(Wednesday night through Tuesday)

The slow moving cold front is forecast to be near the I-20
corridor by Wednesday evening. A potent shortwave trough is
progged to be lifting northeast across Far West TX by this time,
increasing large scale forcing for ascent. Precipitable water
values will be in the 1.4 to 1.6" range, providing ample moisture
for convective development. As thunderstorms develop along/north
of this cold front, southerly winds above the boundary layer will
feed Gulf moisture into the complex. This will help propagate the
cold front slowly south across the CWA through Thursday morning,
with east to northeast surface winds developing across West
Central TX. Relatively weak winds aloft will result in slower
storm motions, enhancing the potential for locally heavy rainfall.
Another Flash Flood Watch may be required for this period.

The best rain chances shift to the southern zones on Thursday as
slightly drier air advects into the area behind this cold front.
Cooler temperatures are anticipated on Thursday, with highs in the
mid/upper 60s across the Big Country to the mid 70s along the I-10
corridor. The next shortwave trough is progged to approach West TX
Thursday and Thursday night. Rain chances ramp up accordingly, as
fairly widespread convection is anticipated across West Central
TX. Additional locally heavy rainfall will be possible during the
overnight hours.

Southerly winds are forecast to resume on Friday as the
aforementioned surface boundary washes out. Temperatures are
expected to respond by warming into the upper 70s to lower 80s.
Again, showers and thunderstorms will be possible, especially
during the afternoon and evening hours as thunderstorms over the
Permian Basin drift east into West Central TX.

The weather pattern over the weekend suggests a potential not only
for heavy rainfall, but also for severe weather. Southwest flow
aloft increases as a strong shortwave trough moves slowly east
across the Four Corners. Warmer surface temperatures, rich Gulf
moisture, and steepening mid-level lapse rates will increase the
potential for strong to severe thunderstorms.

In summary, showers and thunderstorms will be possible areawide
through Monday. The severe weather threat will be relatively low,
albeit still present. The potential for severe thunderstorms will
increase this weekend. Heavy rainfall will be the primary concern
through the period. Total rainfall amounts exceeding 4 inches are
possible.

Johnson

&&

.PRELIMINARY POINT TEMPS/POPS...
Abilene  68  78  59  69  60 /  40  40  50  30  60
San Angelo  68  83  63  73  63 /  30  30  60  40  60
Junction  69  83  67  77  65 /  20  20  60  50  50

&&

.SJT WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH until 10 PM CDT this evening FOR THE FOLLOWING
ZONES: Brown...Callahan...Coke...Coleman...Concho...Fisher...
Haskell...Irion...Jones...McCulloch...Nolan...Runnels...San
Saba...Shackelford...Sterling...Taylor...Throckmorton...Tom
Green.

&&

$$

Daniels





AREA FORECAST DISCUSSION

NWS SAN ANGELO TX

 353 PM CDT Tue May 19 2015

.SHORT TERM...
(Today and Tonight)

...Flash flood Watch has been extended until 10 PM CDT tonight for
the Big Country, Concho Valley, and Heartland...

The atmosphere is unstable this afternoon with RUC SB CAPES of
4000 J/KG. Severe storms are certainly possible this afternoon and
evening with the very strong instability. Strong storms were
already developing in the Trans Pecos and eastern Permian basin,
where less stratus was bringing more heating and instability.
These will likely move eastward into the Concho Valley this
evening. Scattered showers and thunderstorms were also developing
from Robert Lee to Brownwood, then northward into the Big Country.

With saturated soil conditions from Wednesday storms, the flash
flood watch has been extended to 10 PM CDT to catch the evening
storms. While coverage is expected to be less, excessive rainfall
rates from slow moving storms will likely cause localized flash
flooding on saturated soils. The atmosphere remains very moist,
with the SPC mesoanalysis page indicating very high precipitable
waters of 1.5 to 1.7 inches, which could bring very efficient
rainfall production.

Wednesday, a cold front will move into the Big Country in the
afternoon, and through the rest of West Central Texas overnight.
The atmosphere will remain unstable, and the front may be a
focus for severe thunderstorm development and localized flooding.

04

.LONG TERM...
(Wednesday night through Tuesday)

The slow moving cold front is forecast to be near the I-20
corridor by Wednesday evening. A potent shortwave trough is
progged to be lifting northeast across Far West TX by this time,
increasing large scale forcing for ascent. Precipitable water
values will be in the 1.4 to 1.6" range, providing ample moisture
for convective development. As thunderstorms develop along/north
of this cold front, southerly winds above the boundary layer will
feed Gulf moisture into the complex. This will help propagate the
cold front slowly south across the CWA through Thursday morning,
with east to northeast surface winds developing across West
Central TX. Relatively weak winds aloft will result in slower
storm motions, enhancing the potential for locally heavy rainfall.
Another Flash Flood Watch may be required for this period.

The best rain chances shift to the southern zones on Thursday as
slightly drier air advects into the area behind this cold front.
Cooler temperatures are anticipated on Thursday, with highs in the
mid/upper 60s across the Big Country to the mid 70s along the I-10
corridor. The next shortwave trough is progged to approach West TX
Thursday and Thursday night. Rain chances ramp up accordingly, as
fairly widespread convection is anticipated across West Central
TX. Additional locally heavy rainfall will be possible during the
overnight hours.

Southerly winds are forecast to resume on Friday as the
aforementioned surface boundary washes out. Temperatures are
expected to respond by warming into the upper 70s to lower 80s.
Again, showers and thunderstorms will be possible, especially
during the afternoon and evening hours as thunderstorms over the
Permian Basin drift east into West Central TX.

The weather pattern over the weekend suggests a potential not only
for heavy rainfall, but also for severe weather. Southwest flow
aloft increases as a strong shortwave trough moves slowly east
across the Four Corners. Warmer surface temperatures, rich Gulf
moisture, and steepening mid-level lapse rates will increase the
potential for strong to severe thunderstorms.

In summary, showers and thunderstorms will be possible areawide
through Monday. The severe weather threat will be relatively low,
albeit still present. The potential for severe thunderstorms will
increase this weekend. Heavy rainfall will be the primary concern
through the period. Total rainfall amounts exceeding 4 inches are
possible.

Johnson

&&

.PRELIMINARY POINT TEMPS/POPS...
Abilene  68  78  59  69  60 /  40  40  50  30  60
San Angelo  68  83  63  73  63 /  30  30  60  40  60
Junction  69  83  67  77  65 /  20  20  60  50  50

&&

.SJT WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH until 10 PM CDT this evening FOR THE FOLLOWING
ZONES: Brown...Callahan...Coke...Coleman...Concho...Fisher...
Haskell...Irion...Jones...McCulloch...Nolan...Runnels...San
Saba...Shackelford...Sterling...Taylor...Throckmorton...Tom
Green.

&&

$$

04/25






AREA FORECAST DISCUSSION

NWS AUSTIN/SAN ANTONIO TX

 1258 PM CDT TUE MAY 19 2015

.AVIATION...
MVFR CIGS HAVE LIFTED IN SAN ANTONIO AND WILL WITHIN THE NEXT
COUPLE OF HOURS IN DRT AND AUS. SOUTHEASTERLY WINDS WILL GUST IN
THE LOW 20 KTS THIS AFTERNOON. THERE IS A SLIGHT CHANCE FOR
SHRA/TSRA THIS AFTERNOON...BUT PROBABILITY IS TOO LOW TO INCLUDE
IN THE TAFS. CIGS WILL LOWER AGAIN LATER TONIGHT AT ALL TERMINALS
EVENTUALLY DROPPING TO IFR IN AUSTIN AND SAN ANTONIO.

&&

.PREV DISCUSSION... /ISSUED 832 AM CDT TUE MAY 19 2015/

UPDATE...
MORNING SHOWER ACTIVITY IS INCREASING OVER THE NORTHERN COUNTIES
AS MOISTURE FEEDS INTO THE MCV IN THE FWD CWA. UPPED POPS A BIT IN
THIS REGION TO ACCOUNT FOR THIS NEW ACTIVITY. OTHERWISE...NO MAJOR
CHANGES WERE MADE TO THE FORECAST.

PREV DISCUSSION... /ISSUED 357 AM CDT TUE MAY 19 2015/

SHORT TERM (TODAY THROUGH WEDNESDAY)...
A SLOW MOVING MCS OVER WEST CENTRAL TX IS PRODUCING FLASH
FLOODING OVER THE SAN ANGELO AREA EARLY THIS MORNING. IN THE PAST
HOUR OR SO...THE SOUTHERN PORTION OF THE COMPLEX IS TAKING OVER
AND SHOWING A MORE FORWARD PROPAGATING TREND. HI-RES MODEL
SUGGESTED CORFIDI VECTORS SUGGEST THE STORMS TO REMAIN MOSTLY IN
THE FORECAST AREAS TO THE NORTH...BUT AS NOTED IN THE LATEST
SPENES AND FFGMPD DISCUSSIONS...DIFFLUENCE ALOFT IS CAUSING HI-
RES SOLUTIONS TO SLOW DOWN THE MOTION WITH THE SYSTEM EXPECTED
BECOME MORE DISORGANIZED AND SLOWER TOWARD DAYBREAK. UPSHEAR
PROPAGATION VECTORS AND MODEL DEPICTIONS OF AN INCREASING MOISTURE
TAP LATER IN THE MORNING WOULD SUGGEST THAT WE SHOULD CONSIDER AT
LEAST A MENTION OF LOCALLY HEAVY RAINFALL OVER THE NORTHERN HILL
COUNTRY INTO THE NORTHERN PART OF AUSTIN METRO FOR TODAY. SHOULD
THE HRRR CONTINUE TO ADVERTISE ROBUST STORM DEVELOPMENT FURTHER
DOWN THE I-35 CORRIDOR...WE MAY CONSIDER A RAISE OF POPS AND
EXPANSION OF THE HEAVY RAINFALL MENTION. OTHER HI-RES MODELS SHOW
POOR AGREEMENT ON THESE SHORT-TERM TRENDS...SO WITH LOW CONFIDENCE
WILL NOT EXPRESS A CONCERN OVER THE SATURATED SOILS OR THE NEED
FOR A FFA AT THIS TIME.

ASIDE FROM THE ACTIVITY AFFECTING NORTHERN COUNTIES TODAY...OVERALL
MODEL TRENDS HAVE BEEN CONSISTENT FOR A RELATIVELY STABLE FORECAST
FOR OUR SOUTHERN COUNTIES TODAY INTO WEDNESDAY. FORECAST WEAK 700
MB RIDGING SHOULD LEAD TO EVEN LESS CONVECTIVE ACTIVITY FOR
DAYTIME WEDNESDAY THAN TODAY.

LONG TERM (WEDNESDAY NIGHT THROUGH MONDAY)...
THE RECOVERY TIME FOR SOUTH CENTRAL TX SOILS AND RIVERS IS SHORT
AS MODEL CONSENSUS NOW SHOWS GOOD AGREEMENT ON A COLD FRONT FOCUS
FOR MORE CONVECTION WEDNESDAY NIGHT INTO THURSDAY. THE MORE
DISTINCT INDICATION OF THE FRONT WOULD SUGGEST THAT THE FRONT
COULD POSSIBLY REMOVE SOME OF THE LOW LEVEL MOISTURE AND LEAD TO
LIGHTER RAINFALL TOTALS INITIALLY. SOME BRIEF HEAVY DOWNPOURS AND
A FEW STRONG STORMS COULD OCCUR WEDNESDAY EVENING GIVEN THE
EVENING TIMING EXPECTED.

MODELS SHOW HIGHEST QPF CONCENTRATIONS SHIFTING TO WESTERN
COUNTIES BY LATE THURSDAY WHERE ELEVATED MOISTURE POOLING IS
PINNED AGAINST THE HIGHER TERRAIN TO THE WEST. THE WEAK MID-LEVEL
RIDGING IS CLEARS OUT BY THEN...AND OVERRUNNING OF THE UNSTABLE
MOIST AIR SHOULD BE ABLE TO SPREAD EAST ACROSS ALL AREAS THURSDAY
NIGHT INTO FRIDAY WITH MULTIPLE ROUNDS OF ELEVATED STORMS THAT
TRANSITION INTO DEEPER CONVECTION BY FRIDAY. AT SOME POINT A FLASH
FLOOD WATCH WILL PROBABLY BE ISSUED...POSSIBLY AS EARLY AS
THURSDAY NIGHT. THE HEAVIEST RAINFALL CONCERN IS SAVED FOR
MEMORIAL DAY WEEKEND...AND WITH ALL MODELS SHOWING A GOOD PATTERN
FOR A SLOW MOVING COMPLEX ENHANCED BY A HIGH AMPLITUDE UPPER
TROUGH...WILL SHOW MOST OF THE ATTENTION FOR LATE SATURDAY THROUGH
LATE SUNDAY.

&&

.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY              72  86  70  80  68 /  30  20  30  40  40
AUSTIN BERGSTROM INTL AIRPORT  71  85  69  80  67 /  20  20  30  40  40
NEW BRAUNFELS MUNI AIRPORT     71  85  71  81  68 /  20  20  20  40  30
BURNET MUNI AIRPORT            70  84  67  76  65 /  30  20  40  40  50
DEL RIO INTL AIRPORT           73  86  71  82  69 /  20  20  50  50  60
GEORGETOWN MUNI AIRPORT        71  84  68  77  66 /  20  20  30  40  40
HONDO MUNI AIRPORT             71  85  71  82  69 /  30  20  40  40  40
SAN MARCOS MUNI AIRPORT        72  85  70  80  68 /  20  20  20  40  40
LA GRANGE - FAYETTE REGIONAL   73  86  71  82  70 /  10  20  20  50  40
SAN ANTONIO INTL AIRPORT       72  85  72  81  69 /  30  20  30  40  40
STINSON MUNI AIRPORT           72  87  73  82  70 /  20  20  30  40  40

&&

.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

MESOSCALE/AVIATION...05/TB3
SYNOPTIC/GRIDS...HAMPSHIRE
PUBLIC SERVICE/DATA COLLECTION...TREADWAY



AREA FORECAST DISCUSSION

NWS BLACKSBURG VA

 358 PM EDT TUE MAY 19 2015

.SYNOPSIS...
HIGH PRESSURE OVER THE OHIO VALLEY AND UPPER MIDWEST WILL MOVE
EAST TONIGHT...INTRODUCING A MUCH DRIER AIRMASS TO THE MID
ATLANTIC REGION FOR WEDNESDAY. AN UPPER LEVEL DISTURBANCE WILL
PASS ACROSS THE REGION THURSDAY...FOLLOWED BY TRANQUIL WEATHER
FOR FRIDAY AND SATURDAY COURTESY OF DRY HIGH PRESSURE.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
AS OF 345 PM EDT TUESDAY...

CHANGE IN AIRMASS IS UNDERWAY WITH FALLING DEWPOINTS. SURFACE COLD
FRONT HAS MOVED EAST OF THE MOUNTAINS. ANY SHOWER ACTIVITY WILL
QUICKLY MOVE EAST THIS EVENING AND AWAY FROM THE FORECAST AREA.
TREND THROUGH THE EVENING WILL BE FOR CLEARING SKIES WITH FAIR/DRY
WEATHER EXPECTED THE NEXT 24 HOURS PER HIGH PRESSURE WHICH IS
BUILDING INTO THE MID ATLANTIC REGION FROM THE NORTHWEST.

TEMPERATURES TONIGHT AND WEDNESDAY WILL ACTUALLY RESEMBLE
SOMETHING CLOSE TO NORMAL WITH 50S FOR LOWS AND 70S TO AROUND 80
FOR HIGHS. WITH LOW DEWPOINTS FORECAST FOR WEDNESDAY...AFTERNOON
HUMIDITY MINIMUMS MAY DIP TO BETWEEN 25-30 PERCENT.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
AS OF 330 PM EDT TUESDAY...

A GOOD DEGREE OF UNCERTAINTY IN THE FORECAST EARLY IN THE SHORT TERM
PERIOD AS GUIDANCE DIFFERENCES ON HANDLING OF SURFACE FEATURES...
WHICH WILL HAVE AN IMPACT ON RAIN CHANCES WEDNESDAY NIGHT THROUGH
THURSDAY. SHORT WAVE ENERGY EJECTING OUT OF AN WESTERN UPPER LEVEL
RIDGE WILL COMBINE WITH SOME SHORT WAVE ENERGY ROTATING AROUND AN
UPPER TROF OVER THE GREAT LAKES AND HEAD IN OUR DIRECTION. THIS
WILL HELP DRIVE DEVELOPMENT OF A SURFACE LOW OVER THE SOUTHEAST US
LATE WEDNESDAY NIGHT...WHICH WILL THEN MOVE OFF THE MIDDLE ATLANTIC
COAST BY THURSDAY NIGHT. THE OPERATIONAL GFS RUN IS ON BOARD WITH
OTHER MODELS IN HANDLING OF DYNAMICS BUT IS MUCH LESS AGGRESSIVE AND
FURTHER EAST IN DEVELOPING PRECIPITATION OVER THE AREA. OTHER
OPERATIONAL RUNS AND ENSEMBLES DO GENERATE A MUCH MORE COHESIVE
PRECIPITATION SHIELD NORTH AND WEST OF THE LOW ASSOCIATED WITH
ENHANCED LIFT IN DEFORMATION AREAS AND RR QUAD OF UPPER JET WHERE WE
NORMALLY EXPECT TO SEE THESE FEATURES. THUS WILL LEAN TOWARD THE
WETTER GUIDANCE AND RAMP POPS UP TO HIGH CHANCE FOR MOST AREAS BY
LATE WED NIGHT AND THROUGH THURSDAY. BELIEVE THUNDER CHANCES WILL
STAY JUST SOUTH OF THE FOOTHILLS/PIEDMONT OF NC SINCE WE WILL BE IN
A COOLER AND MORE STABLE ENVIRONMENT WITH THE LOW TRACKING TO OUR
SOUTH. AS THE LOW DEPARTS THURSDAY NIGHT...HIGH PRESSURE WILL BUILD
IN FROM THE UPPER MIDWEST AND WE WILL SEE STEADILY IMPROVING
CONDITIONS WITH QUIET WEATHER EXPECTED AS WE HEAD INTO THE WEEKEND.

TEMPERATURES WILL START OFF A BIT COOL ON THURSDAY WITH
PRECIPITATION ON THE COOL SIDE OF THE LOW...BUT VALUES WILL REBOUND
TO SEASONAL LEVELS WITH GENERALLY UPPER 60S/AROUND 70 BLUE RIDGE
WEST AND LOW TO MID 70S EAST.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 330 PM EDT TUESDAY...

UPPER PATTERN WILL BE DEVELOPING A LARGE TROF OVER THE EASTERN US
DURING THE EXTENDED PERIOD...WITH A BERMUDA HIGH OFF THE COAST. THIS
WILL GIVE US A VERY COMFORTABLE AND PLEASANT SATURDAY FOLLOWED BY
HEAT AND HUMIDITY MOVING BACK INTO THE REGION BY SUNDAY...WITH THE
TRULY UNCOMFORTABLE CONDITIONS HOLDING OFF UNTIL THE FIRST PART OF
NEXT WEEK. HOWEVER THE CHANCES FOR SHOWERS AND THUNDERSTORMS WILL BE
ONLY MODEST AS SIGNIFICANT DYNAMIC FORCING WILL BE ABSENT...LEAVING
US TO RELY ON OROGRAPHIC FORCING FROM THE BLUE RIDGE WEST TO FOCUS
LIFT AND GENERATE SOME CONVECTIVE ACTIVITY. PWATS WILL ONCE AGAIN BE
RISING ABOVE ONE INCH SO THE POSSIBILITY OF LOCAL DOWNPOURS WILL BE
INCREASING. BY TUESDAY A COLD FRONT WILL BE APPROACHING FROM THE
WEST AND LOOKS TO BRING GREATER COVERAGE OF PRECIPITATION TO THE
REGION TUESDAY AFTERNOON AND EVENING. AFTER A COMFORTABLE
SATURDAY...EXPECT RISING TEMPERATURES TO BE ABOUT 10 DEGREES ABOVE
NORMAL AS WE HEAD INTO NEXT WEEK.

&&

.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
AS OF 200 PM EDT TUESDAY...

SCATTERED SHOWERS/STORMS OVER THE AREA THIS EVENING WILL
DISSIPATE BY SUNSET. A MUCH DRIER AIRMASS WILL ADVECT INTO THE
FORECAST AREA OVERNIGHT AND WEDNESDAY. THIS DRY AIRMASS WILL
PREVENT DEEP CONVECTION WEDNESDAY.

ASIDE FROM THE SHOWER ACTIVITY THIS EVENING ANTICIPATING MAINLY
VFR THROUGH THE VALID TAF PERIOD. SOME OF THE MODELS INDICATE THAT
A SHALLOW LAYER OF MOISTURE MAY GET TRAPPED UP AGAINST THE WEST
SIDE OF THE APPALACHIANS LATE TONIGHT. THIS MAY RESULT IN A PERIOD
OF LOW STRATUS 4-8FT AGL VCNTY OF KBLF EARLY WEDNESDAY MORNING.
ANY LOW CLOUD THAT DOES FORM SHOULD DISSIPATE QUICKLY WEDNESDAY
MORNING.


EXTENDED AVIATION DISCUSSION...

AN UPPER LEVEL DISTURBANCE WILL LIKELY BRING SOME MVFR CEILINGS
AND SHOWERS BACK INTO THE AREA THURSDAY...MOVING OUT FRIDAY
MORNING...WITH VFR CONDITIONS RETURNING FRIDAY AFTERNOON AND
SATURDAY.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...PM
NEAR TERM...PM
SHORT TERM...MBS
LONG TERM...MBS
AVIATION...PM



AREA FORECAST DISCUSSION

NWS PORTLAND

 240 PM PDT TUE MAY 19 2015

.SYNOPSIS...BROAD LOW PRESSURE CONTINUES TO DOMINATE THE WESTERN
UNITED STATES WITH GENERAL UNSETTLED WEATHER ACROSS THE REGION
THROUGH THE WEEKEND. ONSHORE FLOW SHOULD WEAKEN AGAIN
WEDNESDAY...ALLOWING A RETURN TO WARMER TEMPERATURES AND A SLIGHT
CHANCE OF THUNDER TO SPREAD BACK WEST INTO THE WILLAMETTE VALLEY.
INCREASING ONSHORE FLOW SHOULD KEEP TEMPERATURES NEAR NORMAL
THURSDAY THROUGH THE WEEKEND...AND KEEP THE BEST SHOWER/THUNDERSTORM
CHANCES CONFINED TO THE CASCADES.

&&

.SHORT TERM...TONIGHT THROUGH FRIDAY...CONVECTION BEGAN FIRING UP IN
EARNEST AROUND 1 PM THIS AFTERNOON NEARER THE CASCADE CREST WHERE
THE STRATUS HAD BURNED OFF OR WAS RELATIVELY THIN TO BEGIN WITH.
THERE ARE SOME THIN SPOTS IN THE STRATUS ELSEWHERE OFF THE CASCADES
BUT FIND IT HARD TO BELIEVE THE TEMPERATURES WILL WARM ENOUGH TO
REACH CONVECTIVE TEMPERATURES AROUND THE MID 70S TODAY. BOTTOM LINE
WILL BE A FAR LESS EXCITING EVENING THAN LAST NIGHT THOUGH STILL
HAVE POTENTIAL FOR BRIEF HEAVY RAINS UNDER SOME OF THE CELLS.
SHOWERS WILL GREATLY DIMINISH AGAIN THIS EVENING AS THE SUN SETS.
THERE IS A WEAK LOWER TO MID LEVEL SHORTWAVE ROTATING AROUND THE
NORTHWESTERN PERIPHERY OF THE LOOSELY DEFINED CLOSED UPPER LOW
TRANSITING THE GREAT BASIN TONIGHT. THIS SHORTWAVE MAY HOLD TOGETHER
LONG ENOUGH TO BRING LIGHT CONVECTIVE DEBRIS SHOWERS OVERNIGHT
MAINLY TO THE EASTERN HALF OF LANE COUNTY.

WEDNESDAY CAN LARGELY BE CONSIDERED A TRANSITION DAY AS THE PREVIOUS
UPPER LOW OVER THE DESERT SW WILL HAVE LIFTED AND CONTINUES TO MOVE
NORTHEAST ACROSS THE ROCKIES WHILE ANOTHER UPPER LOW DROPS SOUTH
FROM THE GULF OF ALASKA AND WELL OFFSHORE. AS SUCH THE PACNW WILL
REMAIN IN A MOIST GREY AREA WITH A FAIRLY NON DESCRIPT UPPER LEVEL
FLOW PATTERN. EXPECT ANOTHER MORNING WITH A FAIRLY DEEP STRATUS
LAYER BUT THIS TIME WITH INDICATIONS OF THE LAYER CLEARING BEGINNING
MID-DAY TO EARLY AFTERNOON. UPPER LEVEL CONDITIONS REMAIN MOIST AND
UNSTABLE AND WILL LIKELY PROMOTE ANOTHER DAY OF THUNDERSTORMS.
EXPECT STORMS TO INITIATE OVER THE CASCADES AROUND MID-DAY. THE
LOWER ELEVATIONS WILL NEED THE STRATUS LAYER TO BURN OFF BEFORE
DEEPER CONVECTION CAN DEVELOP. SEEMS LIKE THE NORTH END OF THE
VALLEY MAY CLEAR OUT AS EARLY AS 2 OR 3 PM WHILE THE SOUTH END MAY
NOT BREAK FREE UNTIL CLOSER TO 4 OR 5. WOULD THEN EXPECT THE DEEPER
SHOWERS AND POSSIBLE THUNDERSTORMS TO DEVELOP AN HOUR OR TWO AFTER
THAT. GIVEN A LATE STRATUS BREAKOUT AS EXPECTED...THE SURFACE
INVERSION COULD BREAK RATHER QUICKLY WITH STORMS GOING FROM THE
PROVERBIAL 0 TO 60 FAIRLY QUICKLY. STILL COULD SEE LOCALIZED VERY
HEAVY RAINS BUT WILL NEED TO SORT OUT SOME OF THE DETAILS REGARDING
TIMING AND COVERAGE BEFORE GETTING TOO CONFIDENT ON THE QUALITY
DETAILS.

THURSDAY AND FRIDAY APPEAR TO BRING A ANOTHER COUPLE DAYS OF
INCREASING MARINE LAYER WITH TEMPERATURES BACK DOWN TO THE LOWER
70S. HAVE LOWER CONFIDENCE WITH REGARD TO HOW LONG THE LAYER WILL
LAST ON THURSDAY. FEEL REASONABLY CONFIDENT THERE WILL BE CONVECTION
FOR THE CASCADES AGAIN BUT AM NOT TERRIBLY SURE ABOUT THE LOWER
ELEVATIONS. THAT WILL ALL DEPEND ON THE EXTENT AND DURATION OF THE
STRATUS LAYER. FRIDAY IS A LITTLE MORE CERTAIN AND HAVE REASONABLE
CONFIDENCE THE THUNDERSTORMS WILL STAY EAST OF THE CREST BUT STILL
MIGHT GET ENOUGH INSTABILITY FOR SOME SHOWERS ALONG THE WEST SLOPES.

TEMPERATURES WILL EASILY BE WARMEST TOMORROW AD GIVE THE BEST SHOT
OF VALLEY STORMS WHILE THURSDAY AND FRIDAY WILL DROP BACK CLOSER TO
THE 70 DEGREE MARK. /JBONK

.LONG TERM...FRIDAY NIGHT THROUGH TUESDAY...MODEL GUIDANCE CONTINUES
TO REMAIN IN GENERAL AGREEMENT FOR THE END OF THE WEEK WITH THE
BLOCKING PATTERN CONTINUING WITH HIGH PRESSURE OVER ALASKA AND
WESTERN CANADA ABOVE UPPER LOW PRESSURE SLOWLY SLIDING EAST ACROSS
THE SOUTHWESTERN U.S. AND GREAT BASIN. KEPT SOME SLIGHT CHANCE
SHOWERS IN THE CASCADES FOR THE WEEKEND WITH PERHAPS SHOWERS
ATTEMPTING TO MAKE THEIR WAY INTO THE FOOTHILLS OR EASTERN
VALLEY...THOUGH CONFIDENCE IS LOW. HEIGHTS MAY RISE A BIT FOR THE
START OF THE WEEK THOUGH MODELS DIVERGE CONSIDERABLY IN THE DETAILS
SO CONFIDENCE REMAINS LOWER IN THE SPECIFICS FOR THIS TIME. CULLEN

.AVIATION....MVFR STRATUS THIS AFTERNOON WILL LIKELY LIFT ENOUGH TO
PRODUCE VFR CONDITIONS ACROSS THE INTERIOR THIS EVENING. THERE IS A
CHANCE CONDITIONS COULD FLUCTUATE BETWEEN MVFR AND VFR THIS EVENING
IN POCKETS AROUND THE WILLAMETTE VALLEY DUE TO THE SLOW IMPROVEMENT
THUS FAR TODAY. EITHER WAY...EXPECT CONDITIONS TO DETERIORATE ONCE
AGAIN TO MVFR LATER TONIGHT FOR MOST INTERIOR TAF SITES...LIKELY
BETWEEN 09Z AND 18Z WEDNESDAY. KEUG...KHIO...KSLE WILL LIKELY BE THE
LOCATIONS TO HOLD ONTO VFR CONDITIONS THE LONGEST. COASTAL LOCATIONS
SHOULD STAY SOLIDLY HIGH END IFR TO MVFR THROUGH APPROXIMATELY 18Z
WEDNESDAY BEFORE CONDITIONS LIKELY IMPROVE TO VFR AFTER 18Z
WEDNESDAY.

KPDX AND APPROACHES...MVFR CONDITIONS SHOULD GIVE WAY TO VFR TOWARDS
23Z TUESDAY. IT IS POSSIBLE CONDITIONS COULD FLUCTUATE IN AND OUT OF
HIGH END MVFR CONDITIONS THIS EVENING...BUT EXPECT A DETERIORATION
MORE SOLIDLY INTO MVFR LATER TONIGHT BETWEEN 09Z AND 18Z WEDNESDAY.
PATCHY DRIZZLE IN THE MORNING AGAIN COULD BRING ADDITIONAL IFR
CONDITIONS AFTER 12Z WEDNESDAY...BUT CONFIDENCE IN THIS SCENARIO
DEVELOPING IS LOW. /NEUMAN

&&

.MARINE...SURFACE HIGH PRESSURE AND THERMAL LOW PRESSURE OVER THE
INLAND NORTHWEST SHOULD GENERALLY KEEP WINDS BELOW 20 KT THROUGH THE
UPCOMING WEEKEND. SEAS WILL ALSO HOVER IN THE 3 TO 6 FT RANGE
THROUGH THIS PERIOD. A FRESH NORTHWEST SWELL WILL LIKELY MAKE SEAS A
BIT CHOPPIER THAN NORMAL DESPITE WINDS REMAINING RELATIVELY LIGHT.

STRONG TO VERY STRONG EBBS WILL LIKELY PRODUCE STEEP EBB CHOP THE
NEXT SEVERAL MORNINGS ON THE COLUMBIA RIVER BAR...BUT SEAS SHOULD
REMAIN SMALL ENOUGH THAT SMALL CRAFT ADVISORIES FOR ROUGH BAR DO NOT
APPEAR NECESSARY. /NEUMAN

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...NONE.

&&

$$

INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND

THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.




Area Forecast Discussion
National Weather Service Spokane WA
1146 AM PDT TUE MAY 19 2015

.SYNOPSIS...
A mild, occasionally unsettled pattern will persist over the
region through the week. While most of the area will remain dry,
scattered showers and a few afternoon and evening thunderstorms
will be possible mainly over the southeast and Cascades. A shift
to a cooler and more unsettled pattern is expected for the
upcoming holiday weekend.

&&

.DISCUSSION...
Rest of today...Deep upper level low continues to hover over
northern Utah with moisture and instability streaming westward
over southern Idaho and much of Oregon. Meanwhile most of the
Inland Northwest continues to see relatively drier air filter in
from the northeast due to a strong high pressure east of the
Continental Divide. This drier air mass will ensure that most of
the forecast area sees a dry and mild day. The only locations
which could see some precipitation develop later today would be
across extreme SE Washington and adjacent portions of the Idaho
Panhandle. Models have been insistent that the best potential
instability will develop in this area later today. Whether or not
this instability can produce deep enough convection for showers or
thunderstorms remains uncertain. Yesterday the coverage was quite
limited and all the lightning strikes occurred south and west of
our forecast area. That might be the same story today. Various
runs of the HRRR vary on whether or not to produce convection in
this area. The latest GOES Bufr soundings in that area suggest
a little more heating could tap into the potential instability
and produce some rapidly developing cumulus towers and eventually
some showers. The other area with some convective potential is
near the Cascades. Satellite is already detecting some of this
convection but it looks like the tops are too shallow to produce
preciptiation for now. If it does deepen enough, we would see a
small chance of showers in that area, however the models have been
showing this signature for the last several days and it has yet to
materialize at least during the afternoon hours. fx

&&
.AVIATION...
18Z TAFS: Dry northeast flow will deliver VFR conditions to all
forecast sites. There will be a small chance of -shra that could
develop over extreme SE WA/NC ID and an westward drift could move
them close enough to LWS to warrant the mention of vcsh in their
forecast. The HRRR keeps this threat through 04-06z or so. After
that we should see any chance of convection move out of that area
with VFR conditions prevailing. fx

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        75  50  77  51  78  52 /   0  10   0  10  10  10
Coeur d`Alene  74  49  77  49  77  50 /   0  10   0  10  20  20
Pullman        75  47  77  48  75  47 /  10  10  10  10  30  50
Lewiston       81  53  82  54  80  54 /  10  20  10  20  30  30
Colville       79  49  80  49  82  50 /   0   0   0  10  10  10
Sandpoint      74  45  75  45  76  46 /   0   0   0  10  10  10
Kellogg        75  46  76  46  76  47 /  10  10  10  10  20  30
Moses Lake     82  55  83  55  84  54 /  10   0   0  10  10  10
Wenatchee      83  56  84  58  83  58 /   0  10  10  10  20  20
Omak           82  49  83  50  83  52 /   0   0   0  10  20  20

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&

$$