Alert archive / Maine / Mesoscale Discussions in 2007

Mesoscale Discussion 4

January 1, 20078 counties in Maine

The Storm Prediction Center issued this mesoscale discussion at Jan 1, 2007, 7:43 AM EST for 8 counties in Maine. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Jan 1, 2007, 7:43 AM EST (12:43 UTC)
Expired
Jan 1, 2007, 1:45 PM EST
In force
6 hr
Issued by
the Storm Prediction Center

Counties Androscoggin County, ME, Franklin County, ME, Kennebec County, ME, Oxford County, ME, Penobscot County, ME, Piscataquis County, ME, Somerset County, ME, Waldo County, ME

The radar

The Portland,ME radar (KGYX), 143 km from the middle of the area, began a volume at 12:43 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.

The nearest sounding before it

Gray, ME (KGYX), launched 12:00Z, 0.7 hours before the alert went out and 144 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Gray, ME at 12:00Z on 2007-01-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Gray, ME at 12:00Z on 2007-01-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 303 square meters per square second.1939587897Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
542 m above ground
0-6 km bulk shear
44 kt
0-1 km storm-relative helicity
303 m²/s²
0-3 km storm-relative helicity
488 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
ACUS11 KWNS 011243
SWOMCD
SPC MCD 011243 
MEZ000-NHZ000-011845-

MESOSCALE DISCUSSION 0004
NWS STORM PREDICTION CENTER NORMAN OK
0643 AM CST MON JAN 01 2007

AREAS AFFECTED...ERN NH AND ME

CONCERNING...FREEZING RAIN 

VALID 011243Z - 011845Z

FREEZING RAIN...MIXED AT TIMES WITH SLEET...WILL CONTINUE THIS
MORNING.  HOURLY RATES OF UP TO .05-.07 WILL BE POSSIBLE WITH
PRECIPITATION ENDING FROM WEST TO EAST ACROSS REGION.

INTENSE...SHORT WAVE TROUGH WAS LIFTING NEWD THROUGH THE LOWER GREAT
LAKES THIS MORNING WITH ASSOCIATED...DOWNSTREAM WARM CONVEYOR BELT
SUPPORTING LARGE PRECIPITATION SHIELD FROM THE DELMARVA NEWD THROUGH
THE LOWER HUDSON VALLEY AND MUCH OF NEW ENGLAND.  INDEED...REGIONAL
VWPS INDICATE STRONG LLJ OF 50-60 KTS WHICH IS DRIVING INTENSE WAA
REGIME THROUGH THE LOWER HUDSON VALLEY INTO CNTRL/NRN NEW ENGLAND.

THIS WAA ATOP SUB-FREEZING SURFACE TEMPERATURES HAS RESULTED IN A
FAIRLY WIDESPREAD AREA OF FREEZING RAIN EARLY THIS MORNING WITH
EARLIER OBSERVATIONS FROM INTERIOR MA NWD INTO PORTIONS OF VT/NH
INDICATING RATES OF .05-.07/HR.  EXPECT SIMILAR TRENDS TO CONTINUE
THROUGH THE REMAINDER OF THE MORNING FROM PORTIONS OF E-CNTRL/NRN NH
INTO ME.  PRECIPITATION MAY CHANGE TO RAIN /NAMELY ACROSS CNTRL AND
SRN NH/...PRIOR TO DIMINISHING FROM WEST TO EAST ACROSS REGION AS
SYSTEM DRY SLOT SHIFTS EWD.

BASED ON 12Z GYX SOUNDING...INTENSE VERTICAL MOTION ASSOCIATED WITH
THE LOW-LEVEL WAA REGIME MAY OFFSET LAYER WARMING AND SUFFICIENTLY
COOL 850-700MB WARM NOSE TO SUPPORT A MIX OF SLEET AND FREEZING
RAIN...ESPECIALLY ACROSS PORTIONS OF ME.

..MEAD.. 01/01/2007

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

...NOTICE...
SPC WINTER WEATHER MESOSCALE DISCUSSIONS WILL BE ISSUED ON A
SCHEDULED BASIS FROM DECEMBER 1 THROUGH FEBRUARY 28...FOUR
TIMES A DAY...AROUND 00 UTC...06 UTC...12 UTC...AND 18 UTC
FOR SIGNIFICANT SHORT RANGE WINTER WEATHER EVENTS.

ATTN...WFO...CAR...GYX...

44297134 44957118 46086997 46716903 46606860 46066817
45186812 44606845 43977000 43697099

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jan 1, 2:00 AM ESTMesoscale DiscussionSPCAndroscoggin, Cumberland, Franklin, Oxford, Sagadahoc, York5 hr

Nearby

Mesoscale Discussions in Maine, 2007Every mesoscale discussion in 2007

Sources

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.