Area Forecast Discussion
Issued by NWS Gaylord, MI

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000
FXUS63 KAPX 212331
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
731 PM EDT MON APR 21 2014

.SYNOPSIS...
ISSUED AT 409 PM EDT MON APR 21 2014

LOW PRESSURE WILL CROSS NORTHERN MICHIGAN LATE TODAY...WITH WET
WEATHER LINGERING INTO THIS EVENING. MUCH CHILLIER AIR WILL RETURN
TO THE REGION BEHIND THE LOW. TUESDAY IN PARTICULAR WILL BE COLD AND
WINDY. AFTER TODAY...OUR NEXT BEST CHANCE FOR RAIN WILL BE LATE
THURSDAY INTO FRIDAY...AS LOW PRESSURE MOVES EAST FROM THE PLAINS.

&&

.UPDATE...
ISSUED AT 731 PM EDT MON APR 21 2014

RAIN IS DEPARTING THE AREA A BIT FASTER THAN PREVIOUSLY
ANTICIPATED...AND HAVE SPED THINGS UP BY SEVERAL HOURS BASED ON
RADAR TRENDS. ONE FINAL BATCH OF WEAKENING CONVECTION...TIED TO AN
INCOMING COLD FRONT...MAY TRY TO SURVIVE THE TRIP ACROSS THE LAKE
MICHIGAN ICE COVER BUT WILL IN ALL LIKELIHOOD CONTINUE TO WANE AS
SURFACE-BASED CONVERGENCE WEAKENS OVER THE COLD LAKE AND ANY
REMAINING LAND-BASED INSTABILITY IS GONE. BASED ON OBS AND THE
PATTERN OF A RATHER SOUPY PRE-FRONTAL AIRMASS...HAVE ADDED A
MENTION OF FOG FOR MUCH OF NORTHERN LOWER...AS CURRENT TEMP/DEW
POINT DEPRESSIONS ARE ONLY IN THE 1-3F RANGE AND WINDS ARE LIGHT.
THAT THREAT SHOULD QUICKLY DIMINISH FROM WEST TO EAST AS THE FRONT
AND MUCH DRIER AIR ARRIVE...WITH EVEN A PERIOD OF CLEAR SKIES
POSSIBLE AS A QUICK PUNCH OF SUBSIDENCE AND VERY DRY AIR TRIES TO
WIN OUT. OF COURSE...THIS BEING NORTHERN MICHIGAN THIS SPRING...
LOW CLOUDS STILL ON TRACK PER SATELLITE TRENDS TO ARRIVE TOWARD
07Z...COINCIDENT WITH YET ANOTHER PUSH OF QUITE CHILLY AIR ABOUT
TO HEAD IN OUR DIRECTION AND BRING A LATE WINTER CHILL BACK TO THE
NORTHWOODS FOR TUESDAY. YUCK!

&&

.SHORT TERM...(THIS EVENING THROUGH TONIGHT)
ISSUED AT 409 PM EDT MON APR 21 2014

STALLED FRONT CURRENTLY STRETCHED ACROSS NRN LOWER MICHIGAN
ROUGHLY ALONG OR NORTH OF M-32...CONNECTING BACK TO DEVELOPING LOW
PRESSURE OVER WESTERN UPPER MICHIGAN. W-E ORIENTED MOISTURE
(THETA-E) AXIS STRUNG OUT ALONG/SOUTH OF THE FRONT AS WELL AND
WITH MODEST FORCING ALONG THAT AXIS THROUGH THE DAY...HAS BEEN
THE SOURCE OF ONGOING SHOWER ACTIVITY. HAS BECOME RATHER WARM WELL
SOUTH OF THE FRONT ACROSS CENTRAL LOWER MICHIGAN WHERE TEMPS ARE
PUSHING 80 DEGREES IN THE SAGINAW VALLEY (INCLUDING GLADWIN/ARENAC
COUNTIES) GENERATING AROUND 100 J/KG MLCAPE PER SPC MESO ANALYSIS. SO
NOT SURPRISING...CONVECTION HAS BECOME A BIT MORE ACTIVE ACROSS
THE SE COUNTIES OVER THE LAST HOUR WITH A FEW LIGHTNING STRIKES
AROUND THE WEST BRANCH AREA.

TO THE NORTH...POTENT SHORT WAVE CROSSING SRN ONTARIO/FAR NRN LAKE
SUPERIOR...ALONG NRN EDGE OF UPPER JET STREAK PUSHING ACROSS NRN
MICHIGAN. EASTERN UPPER MICHIGAN HAS BEEN LARGELY STUCK IN LOW
CLOUDS/STRATUS FOR A GOOD PART OF THE DAY ALTHOUGH STRATUS HAS
BEEN THINNING PRETTY WELL OVER THE LAST COUPLE OF HOURS AND TEMPS
CLAWING THEIR WAY TOWARD 50 DEGREES.

TONIGHT...SHORT WAVE TROUGH WILL BE DIGGING INTO THE NRN LAKES
REGION TONIGHT WHILE ENTRANCE REGION OF UPPER JET SWINGS IT/S WAY
ACROSS NRN LOWER MICHIGAN. THIS WILL KICK THE AFOREMENTIONED
STALLED FRONT S/E THROUGH THE CWA THROUGH THE EVENING HOURS. COUPLED
WITH THE UPPER JET ENTRANCE REGION FORCING SWINGING THROUGH AND
MODEST HEATING/INSTABILITY ACROSS NRN LOWER MICHIGAN...EXPECT ONE
MORE ROUND OF MORE WIDESPREAD SHOWERS TO WORK ACROSS NRN LOWER
MICHIGAN THROUGH THE EVENING HOURS. THUNDER THREAT OF COURSE
PRETTY MUCH CONFINED TO THE FAR S/SE COUNTIES WHERE AS MENTIONED
TEMPS ARE PUSHING THE 80 DEGREE MARK.

BEHIND THE FRONT...SUBSTANTIALLY COLDER AIR FOLLOWS OVERNIGHT
HEADING INTO TUESDAY (SAY GOODBYE TO SPRING) WHILE WRAP AROUND LOW
CLOUDS FILL BACK INTO THE REGION TOWARD MORNING. FORECAST SOUNDINGS
SUGGEST WE COULD SEE A LITTLE TERRAIN INDUCED DRIZZLE TOWARD
MORNING AS SATURATED LOW LEVELS DEEPEN TO 4-6K FEET BY MORNING.
OTHERWISE TURNING COLDER WITH SOME GUSTIER NW WINDS DEVELOPING BY
MORNING.

&&

.LONG TERM...(TUESDAY THROUGH MONDAY)
ISSUED AT 409 PM EDT MON APR 21 2014

LARGER SCALE OVERVIEW:  QUASI-ZONAL FLOW BECOMES MORE AMPLIFIED THIS
WEEK WITH INCREASING PACIFIC JET ENERGY AND DEVELOPMENT OF NEGATIVE
NAO.  HIGH LATITUDE GREENLAND BLOCK ALSO BEGINS TO TAKE
SHAPE...HELPING TO PUSH UNSEASONABLY COLD AIR INTO THE GREAT LAKES
/ONCE AGAIN/.  MODEL CONFIDENCE AVERAGE THROUGH MIDWEEK WITH
DECREASING CONFIDENCE END OF THE WEEK INTO THE WEEKEND.

PRIMARY FORECAST CONCERNS/CHALLENGES: TEMPERATURE AND CLOUD TRENDS
THROUGHOUT THE FORECAST. LIGHT PRECIPITATION CHANCES TUESDAY MORNING
AND POSSIBILITIES OF FREEZING PRECIPITATION /EASTERN UPPER/.
TIMING/COVERAGE/AND AMOUNT OF RAINFALL FOR THE END OF THE WEEK AND
POSSIBLE IMPACTS OF SUCH ON AREA RIVERS.

DETAILS: SLUG OF LOW LEVEL MOISTURE SLIDES ACROSS THE AREA THE FIRST
HALF OF TUESDAY WITH PASSAGE OF MID LEVEL WAVE.  MAINLY SUB-800MB
MOISTURE ON FORECAST SOUNDINGS WITH POSSIBILITIES FOR SOME EARLY DAY
DRIZZLE OR EVEN A BIT OF FREEZING DRIZZLE OVER EASTERN UPPER WHERE
SURFACE TEMPS WILL BE A LITTLE COLDER.  DESPITE RELATIVELY SHALLOW
MOISTURE BELOW -10C ON SOUNDINGS...POCKET OF STEEPENING MID LEVEL
LAPSE RATES WITH SHORTWAVE COMBINED WITH LOW LEVEL MOISTURE AND
STRONG COLD AIR ADVECTION SHOULD BE SUFFICIENT TO ALSO PRODUCE A FEW
RAIN/SNOW SHOWERS INTO THE EARLY AFTERNOON.  BEST PRECIPITATION
CHANCES LIKELY TIED TO THE HIGHER TERRAIN...WHERE UPSLOPE FLOW WILL
HELP TO SQUEEZE OUT ADDITIONAL MOISTURE.  MAY ALSO SEE A BIT OF
MOISTURE FLUX OFF OF THE LAKES...ALTHOUGH TEMPS NOT COLD ENOUGH FOR
TRUE LAKE EFFECT PROCESSES.  CLOUDS LIKELY TO HANG AROUND FOR MUCH
OF THE DAY...ESPECIALLY EASTERN 1/2 OF THE AREA.  A RUDE AWAKENING
WITH REGARD TO TEMPERATURES...WITH READINGS IN THE MID 30S TO MID
40S WITH GUSTY NORTHWEST WINDS MAKING IT FEEL COLDER.  OVERALL...NOT
A VERY NICE DAY AND CERTAINLY NOTHING RESEMBLING SPRINGTIME.

A DRY MID-WEEK PERIOD WITH NEAR SEASONABLE TEMPERATURES.  DEEP LAYER
DRY AIR IN PLACE FOR WEDNESDAY WHICH WILL MIX OUT TO SOME LOW
AFTERNOON RH VALUES FIRE WEATHER-WISE.  INCREASING RAIN CHANCES FOR
THE END OF THE WEEK WITH STRONG MODEL CONSENSUS SUPPORTING A DEEP
TROUGH CARVING OUT OVER THE NORTHERN PLAINS. THIS FEATURE WILL THEN
SLIDE SLOWLY ACROSS THE GREAT LAKES TO START THE WEEKEND...BRINGING
AN EXTENDED PERIOD OF UNSETTLED WEATHER TO THE AREA.   BEST CHANCE
FOR WIDESPREAD RAINS THURSDAY NIGHT WITH PUSH OF WARM AIR
ADVECTION.  SOME OF THIS ENTITLE PRECIPITATION COULD FALL AS SNOW
OVER PORTIONS OF EASTERN UPPER WITH H8 TEMPS STILL A FEW DEGREES
BELOW 0C AND INITIAL LOW LEVEL AIRMASS QUITE DRY /LEADING TO
EVAPORATIVE COOLING/.  FRIDAY AND SATURDAY LOOK TO BE MORE OF A
SHOWERY PATTERN WITH SLOW MOVING UPPER TROUGH AND COLD POCKET
ALOFT.  DIMINISHING CONFIDENCE IN THE PATTERN DETAILS HEADING INTO
THE WEEKEND WITH AT LEAST SOME MODEL SUPPORT FOR FURTHER DEEPENING
OF UPSTREAM RIDGING PUSHING COLD ENOUGH AIR FOR SOME MIXED
PRECIPITATION CONCERNS INTO THE AREA.  WILL NOT GET TOO CUTE WITH
THE WORDING THIS FAR OUT AND WILL KEEP THINGS WITH A SIMPLE
RAIN/SNOW WORDING.  TEMPERATURES ONCE AGAIN TAKE A NOSEDIVE...WITH
READINGS 10-20 DEGREES BELOW NORMAL HEADING INTO THE WEEKEND.
THINGS LOOK TO DRY OUT BY SUNDAY INTO MONDAY.  LOTS OF QUESTION
MARKS BEYOND THIS AS ANOTHER LARGE AND SLOW MOVING UPPER LOW
TRAVERSES THE MID SECTION OF THE COUNTRY.  TEMPERATURES WILL
CONTINUE TO AVERAGE BELOW NORMAL.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 731 PM EDT MON APR 21 2014

A HODGE PODGE OF CONDITIONS FOR A FEW MORE HOURS AT THE TERMINAL
SITES...WITH A BRIEF PERIOD OF LOWERING CEILINGS AND PROBABLY
VISIBILITIES IN A RATHER SOUPY AIRMASS...OUT AHEAD OF A COLD FRONT
WORKING ACROSS EASTERN WISCONSIN. COULD SEE A BRIEF BOUT OF IFR
VISBYS IN A FEW SPOTS IN ANY REMAINING SHOWERS...AND WHERE ANY FOG
CAN DEVELOP THROUGH ABOUT 03Z. HOWEVER...THE PASSAGE OF SAID COLD
FRONT AND ENTRAINMENT OF MUCH DRIER AIR INTO NORTHERN MICHIGAN
SHOULD RESULT IN A PERIOD OF RAPID IMPROVEMENT ROUGHLY 03-05Z...
WITH DOWNRIGHT CLEAR SKIES POSSIBLE. HOWEVER...MUCH COLDER AIR
SPILLING BACK INTO THE REGION SHOULD HELP EXPAND A RATHER
EXPANSIVE STRATUS DECK SOUTHWARD ACROSS THE AREA THE SECOND HALF
OF THE NIGHT...WITH A RETURN TO WIDESPREAD MVFR CEILINGS EXPECTED.
NOT OUT OF THE QUESTION WE SEE A FEW LIGHT RAIN OR SNOW SHOWERS
ALSO...BUT THOSE ARE MOST LIKELY INLAND INTO THE HIGHER TERRAIN.
LIGHT/VARIABLE WINDS THIS EVENING WILL SHIFT NORTHWESTERLY AND GET
RATHER GUSTY OVERNIGHT AND ESPECIALLY INTO TUESDAY...WITH PEAK
GUSTS UP AROUND 28-30 KNOTS POSSIBLE.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.

&&

$$

UPDATE...LAWRENCE
SYNOPSIS...JZ
SHORT TERM...ADAM
LONG TERM...JK
AVIATION...LAWRENCE





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