METR 361 Spring, 2019
Exam
2
Directions: This is an Open-notes exam. Use anything you want, including the Internet. You can’t ask each other questions but you can ask me for clarifications (no guarantee that I’ll be able to answer). You have 90 minutes to complete this exam. Answer all parts of all questions in the blue books or write a text or Word file and send to Jerome.Blechman@oneonta.edu.
1. From
12Z March 14, 2019 to 12Z March 15, 2019, there was an outbreak of severe thunderstorms that caused injuries and fatalities. Use the
following maps and loops to help you answer questions 1a and 1b below: Day
1 convective outlook categories, Day
1 convective outlook with severe reports, 200 mb
loop, 300 mb loop, 500 mb height loop, 500 mb NAM vorticity loop, 700 mb,
loop, 850 mb loop, surface map loop, U.S. Radar loop, U.S. IR satellite loop, KDTW
sounding for 00Z March 15, KILN sounding for 18Z March 14, and KBMX sounding
for 18Z March 14. Consider the special
18Z soundings at KILN and KBMX to be representative of the “pre-storm
environment” while the 00Z KDTW sounding is at the time of severe weather.
a. ( 6%) This was the “bomb” storm that produced heavy
snows in the west earlier in the week.
This type of storm often is a severe-weather producer in the
Spring. What is unique about a bomb that
favors both heavy snow and severe thunderstorms? Refer to the maps.
b. ( 18%) The preliminary storm reports had three
separate and distinct groups of severe
events. One of the most unusual aspects
of this event is that in each of the three areas one of the three types of
severe storms outnumbered the other types, namely tornadoes in the south, straight-line
wind in the Ohio river valley, and hail in the north. It wasn’t exclusive in
that each area had some of each severe type but many red dots appeared in
Alabama around KBMX, mostly blue dots appeared in Indiana and Ohio around KILN,
and green dots were in the majority for the northern states, particularly near
KDTW. Give three credible explanations based on what we learned in this class
for this arrangement of the severe thunderstorms. In other words, why were
there tornadoes in the south, outflow wind in the Ohio river valley, and hail
in the north? Refer to specifics on the maps and/or soundings.
2. Use
the following 4-panel synoptic map images downloaded from the PSU
NARR. They show maps for severe
thunderstorm outbreaks on, June 29, 2005, March 15, 2008, June 1, 2011, and May
20, 2013. Severe thunderstorms occurred
in the northeast (Massachusetts, Maine), northern midwest
(Wisconsin, Iowa, Minnesota), southeast coast (South Carolina and Georgia), and
southern Plains through Michigan (shown as Oklahoma and Missouri). Which report map goes with which 4-panel map (answer part a, below)?
Massachusetts,
Maine ___________________________________________________
Wisconsin,
Iowa, Minnesota________________________________________
South
Carolina and North Carolina ___________________________________
Oklahoma
and Missouri. ___________________________________________
a. (8%) Based on the map images, match the correct
maps with the locations of severe weather by writing their dates on the lines
above after the appropriate state names. The arrangement of the map features on
each date should tell you where severe weather most likely happened.
b. ( 8%) For the NARR 4-panel depiction
of May 20, 2013 only, name the one strongest ingredient on each of the four panels
that caused the severe weather in the states you picked for part a. You will have four ingredients. Be sure you note which map panel each
ingredient is found on, (clockwise from upper left:) 500 mb, surface pressure,
850 mb, and 700 mb.
3.
For this question, study the sounding for 12Z at Fort Worth, TX (KFWD) on an
unspecified day.
a. ( 16%) On the paper copy, draw a
parcel line lifted from the surface to the LCL and from there to the
equilibrium level. Mark the LCL, LFC,
and areas of positive CAPE and CINH.
b. ( 3%) What is the Total-Totals index? Estimate what you need from the diagram.
4. This
question concerns the forecast for severe thunderstorms from 13Z March 24
through 12Z March 25, 2019. There is an
area marked SLGT with Little Rock, AR (KLZK) added. The location of that city is the small black
filled circle in the center of Arkansas.
a. ( 4%) What does the designation
SLGT mean, according to the SPC? Include
the threshold probability for SLGT on this Day 1 Outlook.
b. ( 6%) What information is given
in the forecast hodograph for KLZK 00Z March 25 that supports severe
thunderstorms?
c. ( 25%) On each of the NAM
forecast loops for MSLP, 850 mb temp, 850 mb RH, 700 mb, and 250 mb, find one
characteristic or process that favors severe thunderstorms. For each loop, explain what your one characteristic
or process is and how it works to produce or strengthen the storms.