Area forecast discussion
National Weather Service Bismarck ND
1012 am CDT Wednesday may 22 2013
Update...
issued at 1006 am CDT Wednesday may 22 2013
Made only minor adjustments to the current forecast. The 22.12z
NAM and latest rap still suggest a small chance for a shower in
the far southeast corner of the forecast area today. Did not
increase rain chances in that area for the update...but will have
to keep an eye on radar trends in case a stray shower tries to
move in later.
Clouds continue to clear from north to south...with the most
abundant cloud cover in the southern James River Valley as of middle
morning. Adjusted near term sky cover grids to reflect the
trends...with the forecast for this afternoon still on track.
Update issued at 641 am CDT Wednesday may 22 2013
Surface high pressure continues to build into the region this
morning. Enough gradient flow has developed to mix out morning fog
across the northern portions of the state. As of the 11z
observation...there was no fog reported across the northern County Warning Area. As a
result...removed morning fog wording from the grids and zones.
Furthermore...regional radars are not detecting any shower
activity across the southern County Warning Area. Lowered morning probability of precipitation as a
result. Otherwise...adjusted the hourly sensible weather grids
based on current obs/trends. The updated gridded and text products
have been sent.
&&
Short term...(today and tonight)
Issued at 343 am CDT Wednesday may 22 2013
Forecast highlights in the short term period will be dry and cool
weather in the wake of the storm system which brought widespread
heavy rainfall to much of west and central North Dakota the past
several days.
Currently...mostly clear conditions across northern North Dakota
with high pressure slowly building south into the northern plains.
Scattered light rain continues to advect west-southwest further
south...still under the influence of the closed upper low which is
moving slowly south and east into the middle/upper Mississippi Valley
region. Precipitation chances will continue to diminish from north
to south as the low moves out of the region...and skies will
continue to clear from north to south now through 15z. Will maintain
morning fog north with T/dew point spreads nearing zero as skies
clear...and several observing sites reporting fog. Will monitor for
possible dense fog...however winds are expected to increase shortly
after sunrise so do not expect the duration of the fog to be very
long.
The ridge continues to build slowly south across the central
Dakotas today...with generally sunny skies and highs in the 60s. The
latest 00z GFS/European model (ecmwf) do generate 100-200 j/kg of MUCAPE this
afternoon/early evening along a cold front pushing south across
southern Manitoba into northeastern North Dakota. For now will leave
things dry...but could see a shower or two around The Turtle
mountains/Devils Lake basin area.
Another cool night Wednesday thanks to clear skies...light
winds...and surface dewpoints ranging from 35-45. This should result in
low temperatures around 40 to 45. Southeast return flow increases
late tonight far west.
Long term...(thursday through tuesday)
issued at 343 am CDT Wednesday may 22 2013
Dry conditions are expected Thursday as middle/upper level ridging
develops over the plains. Gradient flow will increase west in
response to an upper level low over the Pacific northwest. Wind
Advisory conditions will be possible over southwestern North Dakota
Thursday afternoon/evening.
The medium range models forecast the first impulse to eject from of the
aforementioned Pacific northwest low over western and central North
Dakota Friday. This will lead to thunderstorm chances developing
areawide by Friday afternoon.
An unsettled weather pattern will continue through the end of the
period. Persistent southwesterly flow aloft combined with Gulf of
Mexico moisture tap will lead to chances for thunderstorms each day
this weekend through the first part of next week. The persistent
return flow should also allow for a gradual warming trend to develop
Saturday and continue through the end of the period. By
Tuesday...highs should generally be in the middle 70s.
&&
Aviation...(for the 12z tafs through 12z Thursday morning)
issued at 641 am CDT Wednesday may 22 2013
VFR ceilings all terminals through the 12z taf period. Early morning fog
possible at kmot-kisn through 14z.
&&
Bis watches/warnings/advisories...
none.
&&
$$
Update...ck
short term...New Hampshire
long term...tm
aviation...New Hampshire
