Current Conditions at Sanborn Field
Freeze Warning in effect from April 21 01:00AM CDT until April 21 09:00AM CDT
Tuesday Night - Decreasing clouds. A freeze is likely. Low: 28-32
Wednesday - Partly sunny. Frost in the morning. High: 48-52
Wednesday Night - Decreasing cloud cover. A freeze is likely. Low: 28-32
Thursday - Partly sunny. Rain is possible late. High: 54-58
Friday - Cloudy. Rain possible throughout the day. Thunderstorms possible late. High: 54-58
A freeze warning for the entire state of Missouri is in effect from late tonight until
tomorrow morning at 9am. Temperatures are expected to drop to the high 20s/low 30s
which is well below average for this time of year. These cold nights are expected to
continue throughout the week, so make sure to take every precaution necessary to protect
crops, farm animals, pets, and anything else that could be negatively impacted by the
freezing temperatures. Wednesday will see frost in the morning, but as partly sunny
weather is expected throughout the day, temperatures will climb into the high 40s to low
50s. Another freeze is likely Wednesday night, but partly sunny skies will return on
Thursday and bring us comfortably high temperatures in the mid-50s. Rain is possible
Thursday night and throughout the day Friday, so make sure to pack your umbrella if
you are planning to head out during those times. Thunderstorms are also possible late
Friday night.
====================================================
This forecast was created using the 12Z run of the GFS, GFS soundings, and GEFS and
SREF plumes for temperatures. The GFS was chosen due to its continuity and accuracy
of forecasting the track of the passing cold front and low pressure system to the northeast.
This run of the model also had more accurate initial conditions than the other models at
this time.
Large amounts of divergence at the 250-mb level associated with the passing cold front
and Tuesday’s snowfall event moves out of Missouri by 09Z Wednesday. Missouri will
then fall under the influence of the polar jet, and will remain there for the entirety of the
forecast period. Higher amounts of divergence move into the region Friday at 21Z,
supporting Friday’s opportunity for rainfall and potential thunderstorms.
The 500-mb map of heights and vorticity depict the large amounts of vorticity associated
with the passing cold front. These circulations move out Tuesday night, but smaller
amounts persist into Wednesday, helping create partial cloud cover for Mid-Missouri. 21Z
Thursday and into Friday, higher amounts of vorticity move back into the region. This
supports the start of Thursday night and Friday’s rainfall event. High amounts of vorticity
remain in the region until around 00Z Saturday, increasing Friday evening’s potential for
thunderstorms.
At the 700-mb level, maps of relative humidity suggest moisture moving out of Mid-MO
by 06Z Wednesday. The drier conditions will provide a brief break from precipitation until
00Z Friday, when the abundant moisture returns. This moisture, when combined with the
other factors in higher levels, will lead to rainfall starting late Thursday and continuing
throughout the day Friday. The moisture appears to start moving out of the area by 06Z
Saturday, so future forecasters should watch for the end of this rainfall event.
Missouri will remain under a northwesterly flow at the 850-mb level until around 06Z
Thursday due to the passage of the strong cold front on Tuesday. These winds will cause
temperatures to be below the climatological average for this time of year, and freezes are
possible Tuesday and Wednesday night. The winds finally change around 18Z Thursday
when the passage of a ridge shifts them to a southerly direction. This shift will also form a
LLJ from The Gulf, funneling in moisture for Thursday night’s and Friday’s rain.
At the surface level, a region of high pressure becomes visible around 18Z Wednesday,
and remains in Missouri until 18Z Thursday, supporting the calmer conditions. By 09Z
Friday, Missouri falls under the influence of WAA, and temperatures will soon see a
warming trend.
GFS soundings provide support for Friday’s rainfall and the chance for thunderstorms.
The best chance for thunderstorms is around 21Z Friday. Soundings show high omega
amounts in the saturated levels, MUCAPE with values of 400-500 J/kg, and the LI
reaching a value of -3. These storms don’t appear too strong at the moment, but future
forecasters should keep an eye on them for any further development.
No comments:
Post a Comment