MD 0004 CONCERNING FREEZING RAIN FOR PARTS OF NEBRASKA AND FAR NORTHWEST IOWA
Mesoscale Discussion 0004
NWS Storm Prediction Center Norman OK
0128 PM CST Mon Jan 02 2023
Areas affected...Parts of Nebraska and far northwest Iowa
Concerning...Freezing rain
Valid 021928Z - 030000Z
SUMMARY...Freezing rain with rates up to 0.06 inch/3 hours is
possible this afternoon/early evening across parts of NE into far
northwest IA -- especially northeast NE in the 21-00Z time frame.
DISCUSSION...The nose of a strong south-southwesterly midlevel speed
max will gradually overspread western OK and southwest KS this
afternoon, with related strong DCVA emerging over parts of NE in the
21-00Z time frame. This midlevel ascent, coupled with strengthening
low/midlevel isentropic ascent, will support an increase in
precipitation focused along a southwest-northeast-oriented
low/midlevel baroclinic zone across parts of south-central NE
northeastward into far northwest IA.
Current surface temperatures through this corridor are in the 32-34
F range, and light precipitation and related wet-bulb cooling this
afternoon will support surface temperatures in the 30-32 F range
before precipitation rates increase over the area. These
sufficiently cold surface temperatures beneath a substantial warm
nose at 850-mb should favor freezing rain with rates up to 0.06 inch
per 3 hours given the strengthening/focused ascent. Confidence in
these rates is greatest in northeast NE and perhaps into far
northwest IA between 21-00Z. North of the expected freezing-rain
corridor, colder thermodynamic profiles should favor mixed winter
precipitation including areas of heavy snow. Of note, upslope flow
and favorable freezing-rain thermodynamic profiles over southeast WY
into the NE Panhandle are yielding freezing drizzle, and these
conditions could persist into the evening hours as well.
..Weinman.. 01/02/2023
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...FSD...OAX...GID...LBF...GLD...
LAT...LON 40160026 40060132 40460157 40900088 41350009 42169894
42639814 42809719 42769614 42289597 41499708 41129784
40479941 40160026
