Area Forecast Discussion
Issued by NWS Gaylord, MI

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS63 KAPX 040527
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
127 AM EDT MON MAY 4 2015

.UPDATE...
ISSUED AT 1033 PM EDT SUN MAY 3 2015

LINE OF SHOWERS AND EMBEDDED THUNDERSTORMS CONTINUES TO MAKE SLOW
EASTWARD PROGRESS THRU UPR MICHIGAN AND WISCONSIN TOWARD LWR
MICHIGAN LATE THIS EVENING. NE PORTION OF THIS LINE HAS TENDED TO
DIMINISH IN INTENSITY AS IT MOVES EAST INTO A MUCH DRIER AND MORE
STABLE AIRMASS. SURFACE DWPTS HAVE INCREASED INTO THE 40S THIS
EVENING ACROSS NRN LWR MICHIGAN...AND EXPECT THIS UPWARD TREND
WILL CONTINUE OVERNIGHT AS DWPTS RISE INTO THE 50S THANKS TO
WARM/MOIST AIR ADVECTION AHEAD OF THE COLD FRONT. NOCTURNAL
CONVECTION WILL BE ELEVATED...AND LIMITED INSTABILITY AT THAT WILL
TREND TOWARD WEAK/MAINLY ISOLD THUNDERSTORM ACTIVITY OVERNIGHT.
WILL KEEP CATEGORICAL POPS IN THE OVERNIGHT FORECAST...WITH ONLY A
CHANCE OF THUNDER AS UPSTREAM CONVECTION CONTINUES TO ENCOUNTER
DRIER/MORE STABLE AIR WITH EASTWARD PROGRESS. AT THIS POINT...NO
SEVERE WEATHER IS EXPECTED.

&&

.NEAR TERM...(THIS EVENING THROUGH TONIGHT)
ISSUED AT 400 PM EDT SUN MAY 3 2015

HIGH IMPACT WEATHER: RED FLAG CONDITIONS

FORECAST CHALLENGE: ENDING OF RED FLAG CONDITIONS AND THUNDERSTORM
CHANCES OVERNIGHT.

OVERVIEW...RELATIVELY FLAT 500 MB FLOW OVER THE FORECAST AREA, WITH
A MESO-VORT IN N ILLINOIS THAT WILL PASS TO THE SOUTH OF THE FORECAST
AREA. DESPITE THE MESO VORT PASSING TO THE SOUTH, THE MOISTURE
CIRCULATING AROUND IT PUSHING UP INTO N LOWER AND HAS SHIELDED THE
FORECAST AREA FOR A TIME TO PREVENT SOME OF THE HEATING FOR THE PEAK
OF THE DAY. OTHERWISE, UPSTREAM A COLD FRONT/SFC TROUGH IS PUSHING
INTO THE UPPER GREAT LAKES WITH SHOWERS ASSOCIATED WITH IT. THE
FRONT HAS A TRAILING SPEEDMAX AT 500 MB AS WELL.

DETAILS FOR TONIGHT...WITH THE MID LEVEL MOISTURE PLUME ASSOCIATED
WITH THE 500 MB MESOVORT DOWNSTATE, MOVING EAST, THE CLOUD COVER,
AND THE ISOLATED SHOWERS IN PRESQUE ISLE COUNTY LOOK TO BE ON A
DIMINISHING TREND. THERE HAS BEEN SOME RESPONSE IN THE TEMPERATURES,
AND THUS THE RELATIVE HUMIDITY IS BEGINNING TO DROP AGAIN. HOWEVER,
IT IS BEGINNING TO LOOK LIKE THE MOST PLACES WON`T BE GETTING BELOW
30% LET ALONE 25%. IT IS POSSIBLE THAT SOME LOCATIONS WILL GET
THERE, BUT UNLIKELY MANY SPOTS AS WAS THOUGHT DURING THE MID MORNING
UPDATE. SO THE HUMIDITY RECOVERY WILL BE FAIR, AS THE MOISTURE WITH
THE COLD FRONT, AND THEN THE FRONT ITSELF WILL GET THE REGION INTO
THE MID 80% RANGE.

OF COURSE WITH THE DRY AIR, HAVE BACKED OFF THE CHANCES FOR RAIN
SHOWERS, AND THUNDERSTORMS INITIALLY KEEPING THE BULK AFTER 00Z, AS
THE FRONT GETS CLOSER, WHICH WOULD BE MORE AKIN TO THE ECMWF/NAM
IDEA (AND SOME OF THE HI-RES MODELS AS WELL). HOWEVER, OVERNIGHT IT
LOOKS LIKE THE FRONT WILL PRESS THROUGH MOST OF THE FORECAST AREA,
SO THAT THERE WILL BE A FEW SHOWERS BEFORE 12Z THAT WILL HAVE TO
MOVE THROUGH THE FORECAST AREA. THUNDER IS POSSIBLE, BUT NOT
EXPECTED TO BE SEVERE AS THE SFC BASED CAPE WILL BE LESS THAN 200
J/KG WITH THE FRONT, BUT THE K-INDEX IS AROUND 30. THE SHOWALTER
INDEX WILL BE ABOUT -1C AROUND 06Z, SO WILL EXPECT THAT MOST OF THE
THUNDER WILL BE ELEVATED.

&&

.SHORT TERM...(MONDAY THROUGH WEDNESDAY)
ISSUED AT 400 PM EDT SUN MAY 3 2015

PATTERN OVERVIEW: WATER VAPOR IMAGERY THIS AFTERNOON  REVEALS A
SHORT WAVE IMPULSE MOVING EASTWARD THROUGH EXTREME SRN CANADA NEAR
THE U.S.-CANADIAN BORDER IN MINNESOTA. ASSOCIATED 100 KNOT UPPER JET
STREAK EXTENDS FROM THE UPPER MIDWEST INTO ONTARIO/FAR NRN LAKE
SUPERIOR. PARENT SFC LOW RESIDES OVER HUDSON BAY WITH A TRAILING
COLD FRONT STRETCHING DOWN THROUGH WESTERN LAKE SUPERIOR/FAR WESTERN
WISCONSIN AND INTO THE PLAINS. LOW LEVEL MOISTURE AXIS HAS BEEN
STEADILY ADVANCING INTO THE WESTERN GREAT LAKES AS EVIDENCED BY
EXPANDING CU/AC INTO THE CWA. AHEAD OF THE FRONT...POCKETS OF
SHOWERS/THUNDERSTORMS ONGOING ACROSS THE MIDWEST AND WESTERN GREAT
LAKES WITHIN THE PERSISTENT WARM/MOIST ADVECTION REGIME AND
MARGINALLY UNSTABLE AIRMASS. BUT WE SHOULD SEE THE DEVELOPMENT OF A
DECENT LINE OF SHOWERS/STORMS (QLCS) TAKE OFF ACROSS NW WISCONSIN
INTO IOWA LATE THIS AFTERNOON INTO THIS EVENING AHEAD OF THE
FRONT...WHICH IS STILL EXPECTED TO SPREAD INTO NRN MICHIGAN
TONIGHT.

PATTERN FORECAST: SHORT WAVE/UPPER JET STREAK STRUCTURE SKIRTS THE
UPPER LAKES REGION TONIGHT THROUGH MONDAY DRIVING THE AFOREMENTIONED
COLD FRONT DOWN THROUGH THE STATE AND (HOPEFULLY) BRINGING SOME
NEEDED RAIN TO THE REGION. A SLIGHT COOL-OFF FOLLOWS FOR THE FIRST
HALF OF THE WEEK. BUT REBUILDING HEIGHTS/WARMER AIR RETURNS MIDWEEK
ONWARD AS A FAIRLY STRONG SUBTROPICAL RIDGE SETS-UP ACROSS THE SE
CONUS...NOSING INTO THE GREAT LAKES.

MONDAY/MONDAY NIGHT...SHORT WAVE TROUGH AND UPPER JET STREAK CROSSES
THE NRN LAKES THROUGH THE DAY DRIVING COLD FRONT DOWN THROUGH LOWER
MICHIGAN BEFORE SETTLING/LAYING OUT ACROSS THE LOWER LAKES/OHIO
VALLEY MONDAY NIGHT...WHILE SFC HIGH PRESSURE BUILDS ACROSS NRN
MICHIGAN. SHORT TERM GUIDANCE HAS CERTAINLY TRENDED JUST A TAD
SLOWER WITH FROPA OVER THE LAST FEW RUNS SUGGESTING DWINDLING LINE
OF SHOWERS/THUNDERSTORMS WILL STILL BE ONGOING ACROSS A GOOD PART OF
NRN LOWER MICHIGAN MONDAY MORNING...POSSIBLY LINGERING THROUGH THE
AFTERNOON HOURS OVER THE FAR SE COUNTIES DEPENDING ON JUST HOW
QUICKLY THE FRONT GETS THROUGH NRN LOWER MI. HAVE TWEAKED FORECASTS
ACCORDINGLY TO SLOW TIMING OF PRECIP JUST A BIT ON MONDAY. BUT STILL
REASONABLY CONFIDENT THAT FRONT/ASSOCIATED PRECIP WILL BE OUT OF THE
CWA BY 00Z MONDAY EVENING FOLLOWED BY DRY AND COOLER WEATHER MONDAY
NIGHT AS HIGH PRESSURE AND WEDGE OF DRY AIR SETS UP ACROSS NRN
MICHIGAN.

TUESDAY AND WEDNESDAY...FORECAST TURNS A BIT TRICKIER (AND POSSIBLY
WETTER?) HEADING INTO THE MIDWEEK TIMEFRAME. WESTERN END OF FRONT
LYING OUT ACROSS THE OHIO VALLEY INTO THE PLAINS MONDAY NIGHT...
BEGINS TO BOW BACK NORTHWARD...IN RESPONSE TO SUBTROPICAL RIDGE AXIS
PRESSING INTO THE UPPER MIDWEST AND SHORT WAVE TROUGH LIFTING OUT OF
THE CENTRAL PLAINS BY THAT TIME. TOUGH TO KNOW JUST HOW ACTIVE THE
FRONT WILL BE AT THAT POINT. BUT CERTAINLY THE SIGNS ARE THERE THAT
WE SEE GRADUAL INCREASING CLOUD COVER FROM THE SOUTH TUESDAY INTO
WEDNESDAY AND POSSIBLY A LOW END THREAT FOR SHOWERS CREEPING BACK
INTO NRN LOWER MICHIGAN THROUGH THAT TIME. INHERITED FORECAST
ALREADY HAS THAT IDEA IN PLACE AND WILL JUST MAKE SOME MINOR TWEAKS.
BUT OTHERWISE...MORE SEASONABLE WEATHER WILL CHARACTERIZE THE FIRST
HALF OF THE WORK WEEK BEFORE TEMPS SHOOT BACK UP FOR THE END OF THE
WEEK (SEE BELOW).

&&

.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 400 PM EDT SUN MAY 3 2015

THE PERIOD BEGINS WITH MID-LEVEL RIDGING AND ASSOCIATED SURFACE HIGH
PRESSURE EVER SO SLOWLY SLIDING OFF TO THE EAST WEDNESDAY NIGHT AND
THURSDAY AS A WAVE EJECTS FROM THE WEST COAST INTO THE GREAT PLAINS.
THE PLACEMENT OF THAT WAVE AND ANY IMPACTS IT HAS ON NORTHERN
MICHIGAN WILL DEPEND ON THE STRENGTH AND TIMING OF EJECTION FROM A
DEEPENING TROUGH OVER THE WEST COAST. WHILE CONFIDENCE ISN`T TOO
GREAT AT THIS POINT...HAVE GONE AHEAD AND REMOVED POPS FROM
WEDNESDAY NIGHT WITH ONLY LOW END CHANCE POPS REMAINING FOR THURSDAY
AS THE BEST MOISTURE AND ASCENT SHOULD BE LIMITED TO OUR WEST.
ADDITIONAL PRECIPITATION CHANCES ARRIVE FRIDAY THROUGH THE
WEEKEND...BUT AT THIS TIMEFRAME...HAVE LITTLE CONFIDENCE AS TO THEIR
TIMING AND PLACEMENT.

TEMPERATURES TO WRAP UP THE WORK WEEK CONTINUE TO LOOK QUITE WARM
AND MAY APPROACH 80 DEGREES ACROSS MUCH OF NORTHERN LOWER BOTH
THURSDAY AND FRIDAY AS SOUTHWESTERLY WINDS TRANSPORT WARMTH AND EVEN
SOME STICKY DEW POINTS INTO THE REGION. A BLENDED TEMPERATURE
GUIDANCE APPROACH WOULD SUGGEST TEMPS BACK NEAR OR JUST A COUPLE OF
DEGREES ABOVE CLIMATOLOGY (HIGHS IN THE MIDDLE TO UPPER 60S) FOR
NEXT WEEKEND.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 127 AM EDT MON MAY 4 2015

PERIODS OF MVFR OVERNIGHT/THIS MORNING IN SHRA...THEN VFR.

LINE OF SHRA AHEAD OF A COLD FRONT CROSSING WI/UPPER MI WILL
CONTINUE TO WEAKEN AS INSTABILITY IS LOST. MVFR CIGS/VSBYS STILL
EXPECTED AT TIMES...BUT THUNDER IS WANING FAST. MUCH DRIER AIR
ARRIVES BEHIND THE FRONT THIS AFTERNOON...WITH VFR CONDITIONS.

CURRENT SW WINDS WILL VEER NW TO N THIS AFTERNOON. LLWS DURING THE
EARLY MORNING HUORS...WITH STRONG SW WINDS JUST OFF THE SURFACE.

&&

.MARINE...
ISSUED AT 330 AM EDT SUN MAY 3 2015

WINDS ALONG THE LAKE MICHIGAN HAS BEEN GUSTING ABOVE SMALL CRAFT
CRITERIA SO WILL KEEP THE LAKE MICHIGAN SMALL CRAFT ADVISORY GOING
INTO THE LATE EVENING, THEN ALLOW IT EXPIRE AS THE WINDS DIMINISH
FROM THE SLACK GRADIENT ASSOCIATED WITHE SFC TROUGH THAT WILL PASS
THROUGH THE UPPER GREAT LAKES LAKE OVERNIGHT. HIGH PRESSURE THEN
INTO THE REGION ON MONDAY AND STAYS OVER THE UPPER GREAT LAKES
THROUGH TUESDAY. THIS WILL PRODUCE A SLACK PRESSURE GRADIENT, AND
LIGHT WINDS.


&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 4 AM EDT EARLY THIS MORNING FOR
     LMZ341-342-344>346.

LS...NONE.
&&

$$

UPDATE...MLR
NEAR TERM...JSL
SHORT TERM...ADAM
LONG TERM...GILLEN
AVIATION...JAZ
MARINE...JAZ


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.