Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

fxus63 kfgf 231951 
afdfgf

Area forecast discussion
National Weather Service Grand Forks ND
251 PM CDT Fri Aug 23 2019

Short term...(this evening through Saturday night)
issued at 251 PM CDT Fri Aug 23 2019

Ridging prevails today but is slowly moving eastward as an upper low
approaches from the west. The main challenge is timing the onset of
precipitation tonight into Saturday as dry air remains in place
across the region. Southwest winds turn southerly gradually
overnight and will slowly increase our moisture levels ahead of the
approaching 500 mb trough. Adjustments were made to the forecast to slow
the onset of precipitation on Saturday with increasing pops now
expected during the morning hours.

Quantitative precipitation forecast values will be the next challenge as we are expecting widespread
shower activity with more isolated to scattered thunderstorms within
the showers, giving US an overall expectation of around an inch of
rain. Areas in the footprint of convective activity, however, could
see higher amounts with some guidance suggesting upwards of 2 or
more inches. Winds will increase as the trough approaches with
southerly winds of 15 to 20 mph and gusts upwards of 30 to 35 mph
for Saturday.

Long term...(sunday through friday)
issued at 251 PM CDT Fri Aug 23 2019

Sunday through Tuesday

For Sunday, expect to see rain chances increase and become more
widespread with the progression of the low pressure system. By
Sunday afternoon into Sunday evening, rain chances look to be likely
first in eastern North Dakota and then spread across much of western
Minnesota by the evening. Winds will also be breezy out of the
south. With precipitable water values in the top 10% to top 2.5% across much of
the area for the weekend, some areas may see upwards of 1.5 inches
or more. Since the precipitation is likely to be convective due to
heating, there is a lot of uncertainty as to which specific areas
will see higher amounts. However, total rainfall values of near an
inch to possibly more will be fairly widespread. Rain coverage looks
to decrease on Monday night. For Tuesday, a secondary cold front
will pass through the area bringing cooler temperatures and chances
for isolated showers. Highs will fall to the 60s area-wide for
Tuesday.

Wednesday through Friday

Following the passage of the secondary cold front, much cooler air
is expected to move in during the latter portion of the work week.
The GFS is suggesting a 500mb height anomaly of up to 20 dam below
normal for this time of year, suggesting that the airmass will be
cooler than any that have been seen in the past couple of months.
Fall-like temperatures can be expected, similar to climatological
averages of mid to late September. Temperatures on Wednesday night
and Thursday night could fall into the lower 40s for some areas and
possibly lower if winds are calm and cloud cover is minimal. If
these conditions come to fruition, some guidance suggests the
possibility of isolated frost near the international border. The
main chances for showers during this period will be on Wednesday
with high temperatures remaining in the 60s for the whole period.

&&

Aviation...(for the 18z tafs through 18z Saturday afternoon)
issued at 1220 PM CDT Fri Aug 23 2019

Look for VFR conditions this afternoon into the evening hours with
increasing cloudiness through the overnight. Showers begin moving
into the area after midnight but will remain light and scattered
with a relatively low chance of MVFR cigs. Devils Lake will see
the first rain chances as we head into Saturday with possible MVFR
to IFR cigs, mainly during heavier showers. The system bring US
the rain chances will move slowly east, spreading into the kgfk
and kfar areas during the mid to late morning and into the ktvf
and kbji region during the midday to early afternoon time frame.



&&

Fgf watches/warnings/advisories...
ND...none.
Minnesota...none.
&&

National Weather Service Glossary of Abbreviations