Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion 
National Weather Service Bismarck ND
1132 PM CDT Wednesday Jul 30 2014

Update...
issued at 1132 PM CDT Wednesday Jul 30 2014

Previous forecast mentioned an area of showers and thunderstorms
arriving into northwest North Dakota between 04z and 05z...and
this is right on track. For this update...have followed the nam12/hrrr
and rap13 which indicates scattered to numerous showers and
thunderstorms across northwest North Dakota then shifting south to
near kdik between 09z and 11z. Have increased probability of precipitation based on
areal coverage of showers and thunderstorms per local/regional
radar and latest high resolution guidance. Rest of forecast
remains on track.

Update issued at 956 PM CDT Wednesday Jul 30 2014

Latest radar imagery is showing an area of thunderstorms over
southern Saskatchewan and tracking to the southeast. Latest 01 UTC
hrrr is showing this convection dropping into northwest North
Dakota between 04-05 UTC then becoming less organized as it drops
southeast toward Dickinson...and into the south central. Previous
probability of precipitation had this handled well. Only some minor tweaks were needed.
Will keep a mention of patchy fog mainly north and east of Lake
Sakakawea and the Missouri River. Increasing clouds should help
mitigate fog development over the west.

Update issued at 650 PM CDT Wednesday Jul 30 2014

Latest WV satellite indicates a shortwave along the
Manitoba and Saskatchewan border dropping down the upper level
ridge. Convection with this feature is very spotty and basically
remains north of a Weyburn to Brandon line. Thus eliminated probability of precipitation
across the north late this afternoon and early this evening. Did
keep some isolated shower activity over the northwest middle-late
evening...then into the southwest late tonight as previously
forecast with increasing middle level moisture and another weak wave
working through the mean ridge. High pressure over the area
tonight with light winds and mostly clear skies. Similar setup to
last night...thus added some patchy fog mainly north and east of
Lake Sakakawea and the Missouri River.

&&

Short term...(this evening through thursday)
issued at 350 PM CDT Wednesday Jul 30 2014

Water vapor satellite imagery indicates a middle level shortwave
on the west side of Winnipeg is in phase with another wave
embedded in northwesterly flow aloft near Regina. Associated
showers and thunderstorms in southern Saskatchewan have
dissipated...so the isolated thunderstorm forecast for this
afternoon is a low confidence one despite agreement that the hires
nmm and arw/hrrr all initiate convection ahead of that wave in the
next few hours.

Cloud cover was also increased tomorrow to account for the past
couple days of late morning cumulus development.

Long term...(thursday night through wednesday)
issued at 350 PM CDT Wednesday Jul 30 2014

High latitude blocking will have little impact on middle latitude
weather as weak subtropical flow over Continental U.S. Will allow for
continued warming into next week. The 12 UTC European model (ecmwf)/Gem global/GFS
and 06 UTC gefs suggest that assorted mesoscale convective
vortices will move through the weak flow...so low confidence
chances of thunderstorms will be daily through the period.

&&

Aviation...(for the 06z tafs through 06z Thursday night)
issued at 1132 PM CDT Wednesday Jul 30 2014

Have introduced predominant thunderstorms into kisn overnight
gradually waning by 12z. Will mention a thunderstorms in the vicinity at kdik between 09z and
11z and adjust as necessary for predominant precipitation an area of
showers and thunderstorms move toward the south from kisn through
12z Thursday. Otherwise...VFR ceilings expected with a vcfg at kjms
between 09z and 13z Thursday.

&&

Bis watches/warnings/advisories...
none.
&&

$$

Update...Kansas
short term...scheck
long term...scheck
aviation...Kansas

National Weather Service Glossary of Abbreviations