Weather Synopsis

Current:

Surface/850hPa low situated over Lake Superior, with cyclonic flow on backside bringing strong northerly flow into western SD. Upper low (500/300 hPa) centered over central MN, leading to a decent cool pocket aloft, enhancing cumulus through the region. Surface heating minimized due to strong (30 knots, gusts to 40) NNW wind and partly cloudy skies. Currently only 67F in Philip and holding steady.

Today:

Will continue to see strong NNW winds through the afternoon, sustained near 30 knots, gusting to 40 due to a strong pressure gradient maximized over the Dakotas. This should hold down temperatures and not allow temperatures to maximize their potential, which should be around 78F (26C) with 3C 700 hPa temps. RAW NAM forecasts 77F today, as well as ETA/GFS MOS. However, all models are too warm at the moment, so will undercut a degree or so (75F today), which agrees with the NWS. Partly cloudy skies should be maintained through much of the afternoon with clearing towards the evening. If the clouds clear a little early then we might reach the model numbers.

Tonight:

Clearing skies should allow for good radiational cooling, except the models are forecasting the winds to stay up near 5-10 knots. RAW NAM forecasts 54F, with dewpoint of 50F. ETA MOS 49F, GFS MOS 53F. Last night, with winds 10 knots and dewpoint in the mid-40s, the low was 54F. Considering the dewpoint will be up a bit tonight and winds should be in the 5-10 knots range, we should see a low similar to last night. My forecast: 52F.

Tomorrow:

CLEAR! No models showing any clouds in the forecast for tomorrow. 850 hPa temps increase one degree C, and 700 hPa temps increase to 6C, leading to the possibility of highs maximizing near 84F (29C). As the 500 hPa low and surface low pull to the east, the pressure gradient should reduce considerably, resulting in much lighter winds, allowing for more heating. Decent mixing should still be possible with light winds around 10 knots, mixing to 725 mb. RAW NAM forecasts a high of 79F, ETA MOS 79F, GFS MOS 85F. Considering I am only learning about how high mixing occurs here at an altitude of 700 meters, its difficult to go against the agreement between the ETA MOS and Raw NAM. However, with the GFS MOS going much higher, and mixing forecasted to be substantial, I will go somewhere in between. My forecast: 83F.

Next Few Days:

GFS MOS ensembles have come into better agreement on the temperatures, with Monday in the upper 80s, and Tuesday in the low 90s. The RAW NAM/GFS both hint at the possibilities of upper 90s on Tuesday, the model trends will need to be watched for this possibility. Tuesday also begins the chance (20%) of thunderstorms and showers once again, leading to the greatest chance on Thursday (45%) as a shortwave trough moves through the region coupled with a surface low generating in western colorado driving a warm front into the NE/SD border region. The GFS currently keeps the precipitation shield to the south of the region throughout the next 5 days, but convection off of the hills is still likely as dewpoints will be rising as 850 hPa flow turns from the NNW today to easterly by Tuesday leading to dewpoints in the upper 50s on Wednesday. The unsettled weather should continue through the weekend as low level flow out of the SSE will commence, resulting in upslope convection. Severe weather looks possible Wed and into the weekend, depending on shortwave passages.

7-14 day outlook:

Highs will be much warmer as a large ridge builds over the western United States. Small disturbances in the flow through southern Canada could bring the chance of rain, but this should be minimal as the jet begins its annual treck to the north. Enhanced rainfall looks likely in the Southeast, just where they need it considering the drought last year.