344
FXUS63 KBIS 270520
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
1220 AM CDT Tue Sep 27 2016

.UPDATE...
Issued at 1217 AM CDT Tue Sep 27 2016

no changes to the inherited forecast. Temperatures and dew points
were slower to fall off than what was expected but as with last
night a quick drop toward daybreak is very plausible.

UPDATE Issued at 927 PM CDT Mon Sep 26 2016

No significant changes to the going forecast. Main concern was
the frost advisory and would it need to be extended farther west.
Among other things, looked at 02 UTC temperatures compared to
last night, with a similar setup. The only question was perhaps
eastern portions of Dunn and Stark counties through Hettinger and
Adams counties. Eastern portions of these counties were about the
same as last nights 02 UTC temperatures, but the western portions
of these counties were about 3 degrees warmer than last night,
and farther west over far western ND temperatures were a good 4 to
7 degrees warmer. This is where low level warm advection is
beginning, and should continue through the night. Would like the
12z surface low position to be a little farther east, but already,
dewpoint temperatures at Hettinger and Dickinson have risen into
the upper 30s tonight where last night they remained in the mid
30s. Therefore will keep the frost advisory as is.

Otherwise, a few high clouds west and clear central. Frost
Advisory looks very reasonable across all of central ND where lows
are expected to be in the lower to middle 30s.

UPDATE Issued at 622 PM CDT Mon Sep 26 2016

High pressure will continue to build over the forecast area
tonight. Currently we are still near our max highs for the day,
and it remains breezy along and east of the Highway 83 corridor.
Expect winds to diminish fairly quickly this evening.

No significant changes needed other than a minor increase in
clouds across the west. Will updated latest sensible weather
elements and blend to mid evening temperatures.

Next update we may be able to see how quickly temperatures begin
to fall and thus see if we may need to adjust our current frost
advisory.

Will send updated text products shortly.

&&

.SHORT TERM...(This evening through Tuesday)
Issued at 241 PM CDT Mon Sep 26 2016

Frost tonight highlights the short term forecast.

Issued a Frost Advisory for much of western and central North
Dakota generally east of US Highway 85. Undercut the 12 UTC
guidance consensus for lows tonight given the observed temperature
pattern from this morning which came in cooler than than forecast.
Thus, in a similar setup with good radiational cooling tonight,
widespread lows in the lower to mid 30s are expected for the
aforementioned areas. Across the far west, low level warm air
advection through the night may hold temperatures high enough to
prevent frost. However, this will have to be monitored.

.LONG TERM...(Tuesday night through Monday)
Issued at 241 PM CDT Mon Sep 26 2016

Mild conditions through the period highlight the extended
forecast.

The 12 UTC global suites are in agreement on an upper level ridge
building across the Northern Plains Wednesday and Thursday.
Thereafter, the upper level flow transitions to southwest aloft
across the region on the upstream side of the ridge. This favors
slightly above normal temperatures with highs in the upper 60s and
70s for the period. The chance for showers and thunderstorms
returns Saturday night through Sunday as sufficient moisture may
return to the region coupled with impulses embedded in the upper
level southwest flow potentially ejecting out of the digging west
coast trough.

&&

.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1217 aM CDT Tue Sep 27 2016

VFR weather is forecast through the taf valid period.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
Frost Advisory until 8 AM CDT /7 AM MDT/ this morning for
NDZ002>005-010>013-019>023-025-034>037-042-045>048-050-051.

&&

$$

UPDATE...JPM
short and long term...PJA
AVIATION...JPM