Thursday, April 30, 2020



Thursday Night - Mostly clear. Low: 46-50



Friday - Increasing clouds. High: 74-78



Friday Night - Partly cloudy. Low: 56-60



Saturday  - Mostly sunny. High: 80-84


Sunday - Cloudy, rain possible. High: 70-74


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Discussion: 

Mostly clear skies will continue Thursday night with temperatures falling to near average. Southerly winds will return Friday morning allowing for warmer air to move into Columbia, along with the transport of moisture from the Gulf of Mexico. This moisture will cause clouds to develop and spread across Missouri. Mostly sunny skies will return Saturday with above average temperatures in the low 80’s. This will be the best day in the forecast, so be sure to get outside and enjoy. Clouds are expected to develop Saturday night into early Sunday, bringing the possibility of rain throughout the day. CD
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Forecasters: Lieberman, Dowell, Ritter
Issued:  5:oopm: April 30, 2020.
Technical Discussion (The nerdy stuff we are discussing in class)

We used the GFS and NAM supplemented with SREF and GEFS. The model diagnosis from the WPC recommends a general model blend for this forecast. CD
Taking a current look and beginning with 250MB, there is a jet max located over the east coast stretching from Georgia to Quebec with a value of 110 knots. This leaves Columbia in the convergence entrance region. There is a deep, near neutral trough extending south from Ontario to the Gulf of Mexico. At 500MB, the trough is still existing in the same area. However, there is a second jet max over the Mississippi River valley with values near 100 knots. At 700MB, there is a large swap of moisture from the southeastern Gulf of Mexico extending up the east coast into Quebec. The moisture also wraps back to a large area of circulation over the Michigan/Indiana/Ohio border. Finally, at the surface, there is a low-pressure system over southern Michigan with a cold front sprawling from Pennsylvania to the eastern Gulf of Mexico. CD
Thursday was influenced by a high pressure system bringing the bright blue sunny skies. Mostly clear skies will remain Thursday night with northerly winds. Temperatures will drop near average with a low in the upper 40s to near 50. CD
The trough to the east and ridge to the west result in northerly flow that will continue to bring dry continental air aloft tonight. However, as the ridge axis passes over Missouri, flow will become more zonal. Friday, at 850MB, a low level jet max is strengthening and moving toward Missouri as well. This is advecting moisture into the area Friday throughout the day as we open to the Gulf. The result is increasing clouds.
Friday night, zonal flow will resume. Moderate clouds and slight WAA continuing into the night will result in warmer temperatures than the night before. Saturday morning, primarily westerly flow will bring dry air parcels that have tracked through the southwest. Mostly sunny skies allow for radiational heating and a warmer day than before.
Saturday evening and night, a 250MB jet max over the the Great Lakes puts Missouri in the right entrance region. This jet has a particularly strong wind speed gradient over the Greater Missouri area. This induces rotation at 500MB and UVM in the lower levels. Additionally, 850MB flow shows saturated parcels traveling from the Gulf, through eastern Mexico into the midwest. This may provide sufficient moisture for precipitation Saturday night into Sunday. Convection seems to be of some concern as well. CAPE values exceed 2500J/Kg on some soundings and SREF plumes show a mean of 1700J/Kg. K index and LI show peak values of 37 and -8 respectively on NAM soundings. However, these are limited to the evening and the convective temperature remains fairly high. CIN values also indicate strong capping. For this reason initiation is questionable. In terms of stratiform precipitation, soundings show significant UVM and shallow saturation between 700-900MB around 00Z on Sunday. This mostly decreases from then on with subsequent time steps inspiring little confidence for sustained precip. SREF plumes indicate small quantities of rain are likely but members are in disagreeance on times and quantities. Two members show close to an inch but the mean is around a quarter inch. Scattered, light precip seems possible. Future forecasters should monitor the situation and the possibility for convection.

Wednesday, April 29, 2020




Wednesday Night - Decreasing Clouds. Low: 42-46



Thursday - Sunny Skies. High: 66-70



Thursday Night - Mostly Clear. Low: 46-50



Friday - Mostly Cloudy. High: 74-78



Saturday - Mostly Sunny. High: 80-84


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Discussion: 
 With a massive low-pressure system moving to the east, clouds will stick around into the late evening hours tonight. However, high pressure will begin to build in from the west. Central Missouri will feel its effect, as this high will help to clear out some of the moisture. With northerly winds remaining, temperatures will stay cooler on Thursday, but will still be warm due to the influence of plentiful sunshine. However, winds will switch around to the south during the morning hours on Friday. Those southerly winds will help boost our temperatures into the middle to upper 70’s for the first day of May. The southern winds will also bring in some moisture from the Gulf of Mexico, creating a few clouds for our Friday. Saturday, we will see mostly sunny skies and temperatures in the lower 80’s. Enjoy the weather on Saturday, because we will enter another active pattern to begin next week. 
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Forecasters: Vanderpool, Pauley, Ritter
Issued:  5:oopm: April 29, 2020.
Technical Discussion (The nerdy stuff we are discussing in class)

The main feature in the near-term continues to be the large cyclone rotating over the Great Lakes/Midwest. This low-pressure system was (and continues to be) responsible for the persistent low cloudiness and stiff northerly winds across Mid-Missouri. WPC surface analysis as of 18z indicated that the center of the surface low was located over western Michigan and that the low was just beginning to occlude. Short-range prognostics (next ~24 hours) show this low remaining almost stationary over Michigan, though it will begin to decay later on tonight and into tomorrow as negative vorticity advection occurs on the backside of the 500-mb trough. 

For the local region, models agree that cloud cover will shift east of central MO starting late this afternoon and into the evening. This will leave the forecast area under mostly clear skies tonight, with the northerly flow on the backside of the aforementioned cyclone continuing to contribute to modest cold air advection. This CAA, in combination with the clear skies, will lead to ideal conditions for maximized overnight cooling. Lows are currently forecast to fall into the low to mid-40s. Fog may be a possibility in isolated spots, though this will be dependent upon wind speeds. Currently, surface winds look to remain around 5-10 kt, which should be just strong enough to prevent widespread fog from forming. 

Tomorrow, a beautiful day is in store for Mid-MO as ridging builds in from the west. This will lead to clear skies and moderate winds at the surface. Backing wind profiles indicate that CAA will still be a contributing factor in keeping temperatures slightly cooler than they otherwise would be, but the air to our north just isn’t that chilly. With plentiful sunshine also expected, insolation should be enough to drive temperatures up into the upper 60s to near 70. The mostly clear skies and calm weather will remain into Thursday night, with one more night of fairly light winds and good radiational cooling in store. This will allow lows to fall into the upper 40s, though as the surface high/ridging shifts east, modest warm air advection will begin towards daybreak. 

On Friday, central MO will begin in earnest on another warming trend to kick off May 2020. The GFS indicates strong southerly flow out ahead of a developing cyclone on the lee side slope of the Rockies. This deterministic solution is supported by ensemble guidance, which predicts strong WAA and clear skies contributing to above-average temperatures in the mid to upper 70s. This WAA will also help to bring moisture into the region, with dew points increasing throughout the day. 

By Saturday, the developing surface cyclone is progged to eject into the southern Midwest. However, the cyclone will be fighting a slight ridging pattern aloft at 500-mb, which is not conducive to the strength or even maintenance of the surface low. As a result, model guidance suggests a fizzling of this low. Saturday, therefore, looks to remain dry and sunny, with strong WAA driving temperatures above the 80-degree mark. Chances for precipitation (in the form of rain and thunderstorms) will probably hold off until late Saturday night and Sunday as a shortwave with accompanying vorticity maxima makes its way into Missouri. 

Tuesday, April 28, 2020



Tuesday Night - Cloudy with rain/storms. Low: 48-52

Wednesday - Cloudy with scattered rain. High: 56-60

Wednesday Night - Cloudy with scattered rain. Low: 46-50

Thursday - Sunny. High: 66-70

Friday - Mostly Sunny. High: 74-78

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Discussion: 
The sunny skies and above average temperatures that occurred this afternoon will
transition to cloudy skies with rain and thunderstorms late this afternoon. A cold front will
follow these storms and sweep through the region between 9:00pm and 12:00am. After
that, lingering rain will remain throughout most of the afternoon tomorrow along with
afternoon temperatures nearly 25 degrees colder than today. Skies will clear out
night and temperatures will warm back up to near average for Thursday and Friday
under sunny skies both days. 
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Forecasters: Gallahan, Munley
Issued:  5:oopm: April 28, 2020.
Technical Discussion (The nerdy stuff we are discussing in class)

A 12z blend of ECMWF and GFS were recommended via the WPC. ECMWF was
used for the short-term and GFS was used for Thursday and Friday.

The main topic of concern for this forecast period are the rain and storms forecast
to push through the area this evening ahead of a cold front passing through the area
overnight, and the clearing skies for Thursday and Friday and a return to average
temperatures for those days as well.

With the approaching cold front and storms associated with the front, the variables
used were 500mb vorticity, 700mb RH and UVM, 850mb winds to indicate low level
support to feed these storms. CAPE values for potential uplift an helicity for potential
rotation. Starting out at 500mb vorticity, there is definitely some strong circulation
pushing through the region indicating a potential longwave. That longwave will be followed
by a deepening trough. This indicates a potential change in wind direction which is an
indication of a possible cold front.

700mb UVM and RH values begin to kick up to 25-35 ubar/s and 100% respectively.
This indicates 700mb moisture and lift needed for rain and storm development.

850mb winds indicate good low level support which allows for the southerly moisture
to fuel these storms. This will allow for very good storm development as this low level
moist air will clash with the cold dry air associated with the passing cold front.

The last two ingredients that were looked at were CAPE for potential updraft and helicity
for potential rotation. CAPE values begin to pick up late this afternoon associated with
afternoon heating because of temperatures reaching the low 80s. These CAPE values will
reach as high as 2100 J/Kg which is an indication of good updraft. Helicity values do remain
relatively low throughout, so rotation in these storms look minimal. With that being said,
the main threats are going to be straight-line winds and hail. Total rainfall out of these storms
look to be along the lines of 0.5 to 0.75 inches.

After these storms, winds will begin to back wit height which will usher in CAA and cool
temperatures off for tomorrow by nearly 25 degrees. Rain showers look to remain for most
of the afternoon tomorrow as well. Tomorrow night, skies will clear out due to the previously
passed cold front. Winds will change direction again tomorrow night as well and will begin
to veer with height and usher in WAA and warm southerly air. This will warm temperatures
for Thursday back to average and 5 to 10 degrees above average for Friday.


Monday, April 27, 2020



Monday - Cloudy morning with rain. Sun comes out in the afternoon. 
High: 70-74



Monday Night - Partly cloudy. Low: 54-58


Tuesday - Partly sunny in the morning, with clouds and storms later. 
High: 72-76

 
Tuesday Night - Cloudy with lingering thunderstorms and rain. Low: 48-52

 

Wednesday - Partly sunny and breezy. High: 60-64

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Discussion: 
The current rain affecting the area will likely stop by noon. This brief period of dry time 
and southwesterly winds will allow for sunshine to help warm us up to the low 70s. 
Tomorrow, we begin to see a low pressure system develop to our north. 
Tuesday morning and afternoon, we remain south of the warm front and expect 
temps to rise into the mid and upper 70s. The cold front associated with the low will 
move through the area Tuesday evening. We expect thunderstorms to form along 
and behind the front as it passes. These storms may produce strong winds and 
small hail. Northerly winds behind the cold front and clouds will keep us much 
cooler on Wednesday.
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Forecasters: Clemons, Farr, Heaven
Issued:  10:00am: April 27, 2020
Technical Discussion (The nerdy stuff we are discussing in class)
A general model blend was used for this forecast period as suggested by the WPC. 
A shortwave trough is beginning to embed into the Great Plains and provide activity 
for Mid-Missouri. Rain has been falling in Columbia this morning, picking up <0.15” 
of QPF. Winds are shifting out of the southwest which will allow for moisture advection 
to end very soon, which will dry us out and bring sunshine into the afternoon. The sun 
will make or break our high temperature today as the more we get, the higher the temp
 will end up being. As the shortwave trough amplifies, our attention turns to tomorrow 
as a vertically stacked cyclone is forecasted to push across the upper Mississippi Valley.

This low pressure system forms from the shortwave trough, closing itself off as it moves 
across the Dakotas. From the ground up, this cyclone shows signs of detaching itself
from the general flow across the CONUS. The LLJ shows prominent signs of a warm 
and cold front attached to this low that will ignite storms along its way. Winds shift out of 
the south by tomorrow morning, funnelling moisture back into the central CONUS south 
of the warm front. However, overcast skies will not form until closer to cold FROPA in the 
afternoon/evening, allowing for sunshine to help warm us up and keep the dew point 
temperature over 60 F. This will also make the high temperature tomorrow a little higher 
than today’s.

Soundings ahead of the cold front show ample instability with SREF mean values at 2283 
J/kg for MUCAPE, 1891 J/kg for MLCAPE, and 40 knots for EFFSHR. However, the most 
concerning part of the soundings was that there is no cap forecasted. These thunderstorms 
look to be non-supercellular, which makes the biggest threat to be straight-line winds and 
maybe some small hail if the updraft can grow large enough. However, a few tornadic 
spin-ups cannot be ruled out on the leading edge of the line. The time of focus for these 
thunderstorms is 21Z tomorrow to 00Z Wednesday, and future forecasters will need to 
monitor Tuesday very closely to see how apt it is for convection in the afternoon/evening.

This low pressure system is forecasted to move across the IA-MN border and continue to 
move towards the NE CONUS after all is said and done in Mid-Missouri. Winds will back 
behind the front as expected, allowing for CAA into the area. Temperatures will be much 
cooler on Wednesday thanks to northerly flow behind the low. As the cyclone deepens to 
our east, winds will pick up in the Midwest, with gusts up to 25-35 kts. Models are suggesting 
some lingering morning rain on the backside of this cyclone, but a deep dry layer exists at the 
surface and in the mid-levels which would make it very hard for any precip to make it to the 
ground. Flow from the cP air mass will dry us out on Wednesday and allow for some sun by 
the afternoon.

Friday, April 24, 2020


Friday Night - Overcast with rain. Low: 52 - 56
Saturday - Overcast with rain. High: 58-62
Saturday Night - Clearing through the nightLow: 44-48
Sunday -  Partly cloudy. High: 62 - 66
Monday - Increasing clouds throughout the day. High: 68-72
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Discussion:  

For this weekend, we will be expecting rainfall this weekend as a deep low pressure system 
comes into our forecast area from Saturday into Sunday.  We expect a maximum cumulative 
3 hourly precipitation amount to be 0.2 inches during this period.  We expect temperatures to 
increase from Sunday and Monday as this closed off system moves past us.  




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Forecasters: Balkissoon, Savoy, Heaven
Issued:  5:00pm: April 17, 2020
Technical Discussion (The nerdy stuff we are discussing in class)

WPC model diagnostics suggested a general model blend so we decided to go with GFS. 
SREF was used alongside to supply temperature averages as well as precipitation amounts.

At 250 hPa we see westerly winds at the beginning of our forecasting period,  begin to shift to 
southerly around 3Z on Saturday. These northerly winds stick around until 12Z then shifts to 
northerly. We also noticed an upper level trough that enters Missouri around 6Z on Saturday 
which deepens as it moves through our region. 

As we move down to 500 hPa we notice the trough again entering the region at around 6Z on 
Saturday and continues to deepen until it’s exit at 12Z on Sun.  The system around this time 
period is closed off over Missouri.  There is a deep low and enclosed in the system, vorticity 
max is at the center of the rotation.   With this trough, comes vorticity, which will be an important 
factor in any rain we will be expecting. Small amounts of vorticity were noticed scattered 
throughout the state on Friday but increases as the trough approaches. Max values in our area 
were noticed between 6Z- 18Z on Saturday. As the trough continues to deepen we see another 
peak in vorticity around 15Z on Sunday, with small amounts of scattered vorticity as the trough 
exits the state. The vorticity will play an important role along with other factors to determine our 
chance for continued rain. 

We move further down to the 700 hPa RH and Omega map to further investigate rain chances 
from these products.   From this evening into tomorrow morning we note that very high 
percentages of RH over the entire state of MO.  This persists throughout Saturday and into 
Sunday with intermediate periods of reduced RH values starting on Saturday at 18Z before 
becoming fully saturated over the entire state on Monday at 12Z.  This persists there on out into 
Tuesday.  Comparing the RH values with vertical velocities, we note that there are significant 
values of VV from Saturday 3Z to Sunday 0Z over Missouri.  We see significant lift in central 
Missouri next, from Monday at 12Z into Tuesday.  It is these mentioned times , we expect the 
highest rain chances.    Consulting the skew-Ts, it was confirmed from the GFS sounding 
that throughout Saturday the atmosphere was saturated in Boone County with periods of 
significant lift.   It should be noted that there were no very significant CAPE values for the 
sounding and none of the hodographs were curved,  indicating there we are not expecting 
severe weather and supercell formation.  There are also no  significant SRH values both at 
1km and 3km  which was also supported by the low values of BNR Shear values.  

From the last map we looked at in our top-down approach  was the 850 hPa temperatures 
and heights.  It was noted that throughout the forecast period we are above freezing temperatures 
which implies all precipitation will be in the form of rainfall.  We expect  an average range of 2 - 6 
degrees Celsius over the weekend before temperatures rise in the double digits from Monday 
into Tuesday.