Mesoscale Discussion 252

Issued

Mar 22, 2011, 9:57 PM EDT (01:57 UTC)

Expired

Mar 23, 2011, 3:00 AM EDT

In force

5 hr

Issued by

the Storm Prediction Center

The NCL Michigan radar (KAPX), 111 km from the middle of the area, began a volume at 01:58 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

588 
ACUS11 KWNS 230157
SWOMCD
SPC MCD 230157 
MIZ000-230700-

MESOSCALE DISCUSSION 0252
NWS STORM PREDICTION CENTER NORMAN OK
0857 PM CDT TUE MAR 22 2011

AREAS AFFECTED...NRN AND CNTRL LOWER MI

CONCERNING...WINTER MIXED PRECIPITATION 

VALID 230157Z - 230700Z

SNOW BAND ACROSS CNTRL AND NRN LOWER MI IS BECOMING BETTER DEFINED
AND MORE COMPACT THIS EVENING. WHILE OBS HAVE MAINLY SHOWED LIGHT
SNOWFALL THROUGH MUCH OF THE AFTERNOON INTO EARLY EVENING
HOURS...SNOWFALL RATES OF 1-2 INCHES PER HOUR ARE EXPECTED TO
DEVELOP BETWEEN 03-06Z AND CONTINUE THROUGH THE OVERNIGHT HOURS.
FURTHER SOUTH ACROSS THE MCD AREA...A WINTRY MIX IS MORE LIKELY
THROUGH AT LEAST MIDNIGHT BEFORE TRANSITIONING TO FREEZING RAIN.

A CONSOLIDATING BAND OF SNOWFALL ACROSS CNTRL/NRN LOWER MI IS
EXPECTED TO PRODUCE 1-2 INCH PER HOUR SNOWFALL TONIGHT AS FORCING
FOR ASCENT INCREASES THROUGH MID LEVELS WITH THE APPROACH OF LOW
PRESSURE SYSTEM FROM THE WEST. 00Z MESOANALYSIS INDICATED INCREASING
FRONTOGENESIS AT 850 MB AND 700 MB ATOP SFC BAROCLINIC ZONE FROM
NWRN WI INTO SERN MI. ADDITIONALLY...FORCING WILL FURTHER BE
SUPPORTED BY A COUPLED JET AROUND 500 MB LEADING TO DIVERGENCE
ALOFT. AS ISENTROPIC UPGLIDE OVER WARM FRONT /SITUATED FROM SFC LOW
OVER S-CNTRL IA INTO S-CNTRL OH/ CONTINUES TO BRING ABUNDANT
MOISTURE INTO WARM CONVEYOR BELT...EFFICIENT SNOW PRODUCTION WILL
PERSIST INTO THE EARLY MORNING HOURS. FORECAST MODELS ALSO SUGGEST
SOME MODEST INSTABILITY AND STEEP LAPSE RATES THROUGH THE CRYSTAL
GROWTH ZONE SO PERIODS OF CONVECTIVE SNOW BURSTS CAN NOT BE RULED
OUT...ALONG WITH PERHAPS A LIGHTNING STRIKE.

FURTHER S ACROSS THE MCD AREA...WARMER TEMPERATURE PROFILES WILL
LEAD TO A GREATER THREAT FOR MIXED PRECIP TYPES THROUGH AT LEAST
06Z. THEREAFTER...HI-RES HRRR MODEL SUGGESTS A TRANSITION TO
FREEZING RAIN. FORECAST RUC SOUNDINGS INDICATE A WARM NOSE JUST
ABOVE 850 MB OF AROUND 6 C WITH SFC TEMPERATURES HOVERING NEAR OR
JUST BELOW FREEZING. THIS AREA WILL CERTAINLY BE MORE TRICKY AS THE
AMOUNT OF LOW LEVEL WAA VERSUS WET BULB COOLING AFFECTS WILL PLAY A
ROLE IN PRECIPITATION TYPE.

..STOPPKOTTE.. 03/23/2011

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...DTX...APX...GRR...

LAT...LON   45278642 45478561 45418468 45218363 44968299 44558258
            44268231 43608212 43138211 42698213 42458262 42518328
            42578407 42878551 43158640 43638695 44168733 45278642

Mesoscale Discussions in Michigan, 2011Every mesoscale discussion in 2011

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.