Communicating Winter Weather Threats In Low QPF

Events

“We woke to a beautiful blanket of crystal white snow covering every inch of the landscape. What a fantastic sight!”

“Snow, lovely snow! 8" last night. The temperature dropped to -20. The cold makes everything sparkle so.”

KCOU

KUIN

06z22311sfc.htm

Surface Map – 06z

Forecast Sounding – STL 06z

Forecast Sounding – STL 09Z

Forecast Sounding – STL 12z

“Ice storm this morning. Fell on my butt on the ice in the driveway putting down salt. Hurt like hell”

12 Midnight

1 AM

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ILZ102-MOZ061-063-065-231030-JEFFERSON MO-MONROE IL-ST. CHARLES MO-ST. LOUIS MO-INCLUDING THE CITIES OF...ST CHARLES

.REST OF TONIGHT...CONSIDERABLE CLOUDINESS. SLIGHT CHANCE OFFREEZING RAIN AND RAIN. STEADY OR SLOWLY RISING TEMPERATURES.LIGHT WIND. CHANCE OF PRECIPITATION 20 PERCENT.

ILZ102-MOZ061-063>065-231100-MONROE IL-ST. CHARLES MO-ST. LOUIS MO-ST. LOUIS CITY MO-JEFFERSON MO-INCLUDING THE CITIES OF...ST CHARLES...ST LOUIS

.NOW...PATCHES OF LIGHT RAIN AND FREEZING RAIN WILL BE MOVING INTO THEAREA DURING THE PREDAWN HOURS. WITH TEMPERATURES HOVERING JUSTBELOW FREEZING AT THE ONSET OF THE RAIN...MOTORISTS SHOULD BEALERT FOR ICY CONDITIONS IF THEY DO ENCOUNTER SOME OF THIS LIGHTPRECIPITATION. HOWEVER...TEMPERATURES ARE EXPECTED TO SLOWLY CLIMBDURING THE PREDAWN HOURS AND WILL BE ABOVE FREEZING BYDAYBREAK...ENDING THE FREEZING RAIN THREAT.

$$

Forecast/Weather Update #1

2 AM

3029

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“Electricity's back on, but had another 14" of stupid snow last night. More shoveling. Took all day. Tried to find a neighbor kid to shovel, but they said they're too busy playing hockey. I think they're lying.”

3 AM

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ILZ100>102-MOZ052-061-063>065-231230-MADISON IL-ST. CLAIR IL-MONROE IL-LINCOLN MO-ST. CHARLES MO-ST. LOUIS MO-ST. LOUIS CITY MO-JEFFERSON MO-INCLUDING THE CITIES OF...EDWARDSVILLE...BELLEVILLE...ST CHARLES...ST LOUIS

.NOW...AREAS OF LIGHT FREEZING RAIN...ALONG WITH SPOTTY SLEET... CAN BEEXPECTED FOR THE REMAINDER OF THE PREDAWN HOURS. WITH TEMPERATURESHOVERING JUST BELOW THE FREEZING MARK AT THE ONSET OF THEPRECIPITATION...MOTORISTS SHOULD BE ALERT FOR ICY CONDITIONS IFTHEY DO ENCOUNTER SOME OF THIS LIGHT PRECIPITATION. TEMPERATURESSHOULD CLIMB ABOVE FREEZING MARK EARLY THIS MORNING...ENDING THEFREEZING RAIN THREAT.

ILZ100>102-MOZ061-063>065-231030-JEFFERSON MO-MADISON IL-MONROE IL-ST. CHARLES MO-ST. CLAIR IL-ST. LOUIS CITY MO-ST. LOUIS MO-INCLUDING THE CITIES OF...BELLEVILLE...EDWARDSVILLE...ST CHARLES...ST LOUIS

.REST OF TONIGHT...MOSTLY CLOUDY WITH A 30 PERCENT CHANCE OFFREEZING RAIN AND SLEET. TEMPERATURE SLOWLY RISING TO FREEZING BY DAYBREAK.LIGHT WIND.

Forecast/Weather Update #2

4 AM

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ILZ100>102-MOZ061-063>065-232245-JEFFERSON MO-MADISON IL-MONROE IL-ST. CHARLES MO-ST. CLAIR IL-ST. LOUIS CITY MO-ST. LOUIS MO-INCLUDING THE CITIES OF...BELLEVILLE...EDWARDSVILLE...ST CHARLES...ST LOUIS

.TODAY...MOSTLY CLOUDY. CHANCE OF FREEZING RAIN...SLEET AND RAINEARLY IN THE MORNING...THEN CHANCE OF RAIN IN THE LATE MORNINGAND AFTERNOON. HIGH AROUND 50. SOUTHEAST WIND 10 TO 15 MPH.CHANCE OF PRECIPITATION 40 PERCENT.

“6 inches today. Snow packed so hard by snowplow, l broke the shovel. Thought I was having a heart attack. If I ever catch the jerk who drives that snowplow, I'll drag him through the snow by his hair.”

Forecast/Weather Update #3

ILZ064-065-069-070-074-098>102-MOZ041-042-047>052-059>065-231400-AUDRAIN-BOND IL-BOONE-CALHOUN IL-CALLAWAY-CLINTON IL-COLE-FAYETTE IL-FRANKLIN-GASCONADE-JEFFERSON-JERSEY IL-LINCOLN-MADISON IL-MARION IL-MONITEAU-MONROE IL-MONTGOMERY-OSAGE-ST CHARLES-ST CLAIR IL-ST LOUIS-ST LOUIS CITY-WARREN-WASHINGTON IL-

...AREAS OF FREEZING RAIN AND SLEET OVER CENTRAL AND EAST CENTRALMISSOURI...AND SOUTHWEST ILLINOIS...EARLY THIS MORNING...

A BAND OF FREEZING RAIN AND SLEET WILL PUSH THROUGHCENTRAL AND EASTERN MISSOURI...AS WELL AS SOUTHWEST ILLINOIS...EARLY THIS MORNING. THROUGH 7 AM...THE BULK OF THE PRECIPITATIONWILL BE LOCATED ALONG THE INTERSTATE 70 CORRIDOR IN MISSOURI...ANDALONG AND NORTH OF INTERSTATE 64 IN SOUTHWEST ILLINOIS.

WITH TEMPERATURES HOVERING NEAR AND JUST BELOW THE FREEZING MARK...ICY SPOTS MAY FORM ON SOME ROADS...BRIDGES...AND PARKING LOTS.MOTORISTS SHOULD TAKE THIS THREAT INTO ACCOUNT WHILE DRIVINGTHIS MORNING. SLOW DOWN...USE CAUTION...AND BE ON ALERTFOR CHANGING ROAD CONDITIONS.

TEMPERATURES ARE EXPECTED TO PUSH ABOVE FREEZING BETWEEN 7 AM AND9AM...ENDING THE THREAT OF ICING.

SPECIAL WEATHER STATEMENTNATIONAL WEATHER SERVICE ST LOUIS MO

5 AM

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Hourly Observations 1255 AM PTCLDY 28 21 75 E7 30.23F WCI 21 155 AM PTCLDY 30 22 72 SE8 30.21F WCI 22 255 AM CLOUDY 32 22 66 SE12 30.22R WCI 23 355 AM CLOUDY 32 22 66 SE13 30.20F WCI 22 455 AM FRZ RAIN 32 26 78 SE10 30.21R WCI 24 555 AM FRZ RAIN 32 27 81 SE9 30.21S WCI 24 1255 AM PTCLDY 29 22 75 E5 30.21F WCI 24 155 AM MOCLDY 30 22 72 E5 30.20F WCI 25 255 AM CLOUDY 31 23 72 SE6 30.20S WCI 25 355 AM MIX PCPN 32 23 69 SE7 30.18F WCI 26 455 AM MIX PCPN 31 26 82 SE5 30.19R WCI 26 555 AM CLOUDY 31 26 82 E6 30.19S WCI 25 1255 AM CLEAR 26 21 81 CALM 30.24F 155 AM PTCLDY 27 22 81 E7 30.21F WCI 19 255 AM CLOUDY 29 24 82 S5 30.23R WCI 24 355 AM CLOUDY 30 24 78 SE10 30.20F WCI 21 455 AM CLOUDY 30 26 85 SE8 30.23R WCI 22 555 AM CLOUDY 30 26 85 SE7 30.23S WCI 23

KSTL.08

KSUS.04

KCPS.02

Hourly Observations (cont)1255 AM CLEAR 29 24 82 E6 30.23F WCI 23 155 AM CLEAR 30 24 78 SE6 30.21F WCI 24 255 AM CLOUDY 30 24 78 S6 30.22R WCI 24 355 AM CLOUDY 31 24 75 SE7 30.21F WCI 24 455 AM MIX PCPN 32 25 75 SE12 30.21S WCI 23 555 AM FRZ RAIN 32 28 85 SE8 30.21S FOG WCI 25

KSETT?

KCOU.04

KJEF.06 (some R)

1255 AM MOCLDY 29 23 78 SE14 30.13F WCI 18 155 AM CLOUDY 29 23 78 SE15 30.13S WCI 18 255 AM MIX PCPN 30 25 81 SE10 30.12F WCI 21 355 AM CLOUDY 30 26 85 SE13 30.12S WCI 20 455 AM MIX PCPN 31 28 89 SE10 30.11F FOG WCI 22 555 AM FRZ RAIN 31 29 92 SE17 30.10S WCI 19

1255 AM PTCLDY 32 23 69 E12 30.17S WCI 23 155 AM CLOUDY 32 25 75 E13 30.16F WCI 22 255 AM CLOUDY 32 26 78 E8 30.15F WCI 25 355 AM MIX PCPN 32 29 88 E7 30.15S FOG WCI 26 455 AM CLOUDY 33 30 88 E8 30.14F WCI 26 555 AM CLOUDY 34 29 82 E10 30.14S WCI 26

February 23, 2011

- “At least 60 wrecks” – including 31 Car Pileup on I-64- 21 Injuries, 1 severeIntensity≠ Impact

Determining Impacts…(It Ain’t So Easy)

- Spatial/Temporal Variability Of Precip

- Time of day/week Societal/Meteorological

- Perception

- Pavement ConditionsTemperatures/Treatment/Elevation

And Another Reason…

Presentation has shown an example of how we attempt to convey winter weather threats in light QPF events, using the following products:

• Zones• Nowcasts• Special Weather Statements

Questions…

• Which of those products do you use? (Zones, SPS, Nowcasts)• Is a headline ALWAYS necessary (does what we

have in the forecast matter?)• Do Nowcasts/Special Weather Statements do

any good?• Is there something else we should be using in

these light QPF events?

Tom Blair, MoDOT's St. Louis assistant district engineer, said the meteorologists paid by MoDOT to make predictions about how weather will affect pavement told MoDOT at 4:20 a.m. Wednesday that there was a "chance" of freezing rain.

"They said there was going to be a chance — they didn't say it was going to happen — a chance of freezing rain hitting the St. Louis area," Blair said. "I don't think this was a clear-cut one to them. They shared the forecast as soon as they thought there was a chance. They did not see this coming.“

STL Today – 2/22/2011

Ode To A Snow

Shoveler…

December 9: We woke to a beautiful blanket of crystal white snow covering every inch of the landscape. What a fantastic sight! Can there be a more lovely place in the whole world? Moving here was the best idea I've ever had. I shoveled snow for the first time in years and felt like a boy again. I did both our driveway and the sidewalks. This afternoon the snowplow came along and covered up the sidewalks and closed in the driveway, so I got to shovel again! What a perfect life.

December 12: The sun has melted all our lovely snow. Such a disappointment. My neighbor tells me not to worry, we'll definitely have a white Christmas. No snow on Christmas would be awful! Bob says we'll have so much snow by the end of winter, that I'll never want to see snow again. l don't think that's possible. Bob is such a nice man - I'm glad he's our neighbor.

December 14: Snow, lovely snow! 8" last night. The temperature dropped to -20. The cold makes everything sparkle so. The wind took my breath away, but I warmed up by shoveling the driveway and sidewalks. This is the life! The snowplow came back this afternoon and buried everything again. l didn't realize I would have to do quite this much shoveling, but I'll certainly get back in shape this way. I wish l wouldn't huff and puff so.

December 15: 20 inches forecast. Sold my van and bought a 4x4 Blazer. Bought snow tires for the wife's car and 2 extra shovels. Stocked the freezer. The wife wants a wood stove in case the electricity goes out. I think that's silly. We aren't in Alaska, after all.

December 16: Ice storm this morning. Fell on my butt on the ice in the driveway putting down salt. Hurt like hell. The wife laughed for an hour, which I think was very cruel.

December 17: Still way below freezing. Roads are too icy to go anywhere. Electricity was off for 5 hours. I had to pile the blankets on to stay warm. Nothing to do but stare at the wife and try not to irritate her. Guess I should've bought a wood stove, but won't admit it to her. God I hate it when she's right. I can't believe I'm freezing to death in my own living room.

December 20: Electricity's back on, but had another 14" of stupid snow last night. More shoveling. Took all day. That stupid snowplow came by twice. Tried to find a neighbor kid to shovel, but they said they're too busy playing hockey. I think they're lying. Called the only hardware store around to see about buying a snow blower and they're out. Might have another shipment in March. I think they're lying. Bob says I have to shovel or the city will have it done and bill me. I think he's lying.

December 22: Bob was right about a white Christmas because 13 more inches of the white stuff fell today, and it's so cold it probably won't melt till August. Took me 45 minutes to get all dressed up to go out to shovel and then I had to use the restroom. By the time I got undressed, went and dressed again. I was too tired to shovel. Tried to hire Bob who has a plow on his truck for the rest of the winter; but he says he's too busy. I think the jerk is lying.

December 23: Only 2" of snow today. And it warmed up to 0. The wife wanted me to decorate the front of the house this morning. What is she, nuts? Why didn't she tell me to do that a month ago? She says she did, but I think she's lying.

December 24: 6" today. Snow packed so hard by snowplow, l broke the shovel. Thought I was having a heart attack. If I ever catch the jerk who drives that snowplow, I'll drag him through the snow by his hair. I know he hides around the corner and waits for me to finish shoveling and then he comes down the street at about 100 miles an hour and throws snow all over where I've just been! Tonight the wife wanted me to sing Christmas carols with her and open our presents, but I was busy watching for that stupid snowplow.

December 25: Merry Christmas. 20 more inches of the !=3D@x@!x!x1 slop tonight. Snowed in. The idea of shoveling makes my blood boil. God I hate the snow! Then the snowplow driver came by asking for a donation and I hit him over the head with my shovel. The wife says I have a bad attitude. I think she's an idiot. If I have to watch "It's a Wonderful Life" one more time, I'm going to kill her.

December 26: Still snowed in. Why the hell did I ever move here? It was all HER idea. She's really getting on my nerves.

December 27: Temperature dropped to -30 and the pipes froze.

December 28: Warmed up to above -50. Still snowed in. THAT WOMAN is driving me crazy!!!!!

December 29: 10 more inches. Bob says I have to shovel the roof or it could cave in. That's the silliest thing I ever heard. How dumb does he think I am?

December 30: Roof caved in. The snow plow driver is suing me for a million dollars. The wife went home to her mother. 9" predicted.

December 31: Set fire to what's left of the house. No more shoveling.

January 8: I feel so good. I just love those little white pills they keep giving me. Why am I tied to the bed?