Friday, May 3, 2019

Friday Night - Cloudy with drizzle possible. Low: 50 - 54.

Saturday - Clouds clear out by middle of the day. Allowing for partly sunny skies. High: 66 - 70.

Saturday Night - Mostly clear. Low: 48 - 52.

Sunday - Partly cloudy with showers becoming possible in the evening. High: 72 - 76.

Monday - Cloudy with showers likely and possible some thunderstorms. High: 76 - 80.

Thanks to for the icons!

Tonight trace amounts of rain is possible, before we dry out for Saturday. Saturday afternoon will be a perfect time to go outside when we get some sunshine. Temperatures on Sunday will increase due to clouds not moving in until later in the day. From these clouds we could expect some showers from late Sunday evening through Monday. In the afternoon on Monday conditions look to be favorable for some thunderstorms.

Forecasters: Johnston, Rojas, and Summall.
Issued: 6:11 p.m.; 2 May 2019

Technical Discussion (The nerdy stuff we are discussing in class!)
The WPC at 19Z update mentioned that the ECMWF/UKMET/CMC adjusted toward the somewhat similar 12Z NAM/GFS with the amplitude and timing of the shortwave early Monday such that a general model blend can be used. We used the GFS for our forecasting due to it being more accessible then ECMWF/UKMET/CMC and reaching out to the end of our forecast period. 

A shortwave is located over Kansas and Missouri that will give us a chance for trace amounts of rain. This low-level moisture is also present in soundings. There is a vorticity maximum at 500-mb located over northern Texas through southeast Kansas and radar has reflective values over the same areas into south west Missouri. However, radar looks to keep the heavy precipitation moving more eastward then north so it will stay to our south. Then Saturday a high pressure works its way into our area. Wind profiles on Skew-t’s show backing during the whole day on Saturday. The soundings after 12Z on Saturday have dried out and no longer have clouds until Sunday. 

Sunday a zonal flow will dominate the upper level conditions during Sunday. The day starts drier in the middle troposphere from 700-mb to near 400-mb. The lower level will keep some of the moisture that would increase as the winds shift southwesterly which will allow high clouds formation. The temperature will increase as a result of the upper level clouds that do not represent a significant barrier for the solar radiation. This insolation itself will increase the instability in the atmosphere and from late evening on Sunday through Monday we will experience showers developing.  

A shortwave associated with a 500-mb maximum vorticity passing through the area will be the main concern on Monday while at surface there is stationary low pressure system, with its center remain around west Kansas the entire day. Soundings for the most unstable parcel shows the atmosphere starts to become saturated from top to bottom at 15Z. The 18Z soundings indicates a wind profile with strong veering, vertical motion between 700-mb to 500-mb, CAPE values of 2399 J/kg. The following 3 hours (21Z), CAPE decreases to 1873 J/kg with a cap of 1°C to be overcome. But the BRN reaches 37 which indicates the possibility of supercell formation and upward motion is now located below 850-mb. EHI at this time is 0.2 but increases the following times near to 1 which indicates the possibility of supercell formation.  Based on the reasons mentioned above having deep convection seems likely, but the severity of this event will need to be viewed by future forecasters.

No comments:

Post a Comment